WorldWideScience

Sample records for endurance testing primarily

  1. LMFBR fuel-design environment for endurance testing, primarily of oxide fuel elements with local faults

    International Nuclear Information System (INIS)

    Warinner, D.K.

    1980-01-01

    The US Department of Energy LMFBR Lines-of-Assurance are briefly stated and local faults are given perspective with an historical review and definition to help define the constraints of LMFBR fuel-element designs. Local-fault-propagation (fuel-element failure-propagation and blockage propagation) perceptions are reviewed. Fuel pin designs and major LMFBR parameters affecting pin performance are summarized. The interpretation of failed-fuel data is aided by a discussion of the effects of nonprototypicalities. The fuel-pin endurance expected in the US, USSR, France, UK, Japan, and West Germany is outlined. Finally, fuel-failure detection and location by delayed-neutron and gaseous-fission-product monitors are briefly discussed to better realize the operational limits

  2. Testing of badminton specific endurance

    DEFF Research Database (Denmark)

    Madsen, Christian Møller; Højlyng, Mads; Nybo, Lars

    2016-01-01

    In the present study, a novel intermittent badminton endurance test (B-ENDURANCE) was developed and tested in elite (n=17) and skilled (n=9) badminton players as well as in age-matched physically active men (non-badminton players; n=8). In addition, B-ENDURANCE test-retest reproducibility...... was evaluated in nine badminton players.B-ENDURANCE is an incremental test where each level consists of repeated sequences of badminton specific actions towards the four corners on the court. The subject starts in the center of the court in front of a computer screen and within each sequence he must...... decreases until the subjects cannot follow the dictated tempo.B-ENDURANCE performance for elite players was better (Pbadminton players. In addition, B-ENDURANCE performance correlated (r=0.8; P

  3. 14 CFR 35.39 - Endurance test.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Endurance test. 35.39 Section 35.39... STANDARDS: PROPELLERS Tests and Inspections § 35.39 Endurance test. Endurance tests on the propeller system... propellers must be subjected to one of the following tests: (1) A 50-hour flight test in level flight or in...

  4. Endurance test for DUPIC capsule

    International Nuclear Information System (INIS)

    Chung, Heung June; Bae, K. K.; Lee, C. Y.; Park, J. M.; Ryu, J. S.

    1999-07-01

    This report presents the pressure drop, vibration and endurance test results for mini-plate fuel rig which were designed fabricately by KAERI. From the pressure drop test results, it is noted that the flow rate across the capsule corresponding to the pressure drop of 200 kPa is measured to be about 9.632 kg/sec. Vibration frequency for the capsule ranges from 14 to 18.5 Hz. RMS (Root Mean Square) displacement for the fuel rig is less than 14 μm, and the maximum displacement is less than 54 μm. Based on the endurance test results, the appreciable fretting wear for the DUPIC capsule was not detected. Oxidation on the support tube is observed, also tiny trace of wear between contact points observed. (author). 4 refs., 10 tabs., 45 figs

  5. 14 CFR 33.87 - Endurance test.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Endurance test. 33.87 Section 33.87... STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.87 Endurance test. (a) General. Each engine must be subjected to an endurance test that includes a total of at least 150 hours of operation...

  6. 14 CFR 33.49 - Endurance test.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Endurance test. 33.49 Section 33.49... STANDARDS: AIRCRAFT ENGINES Block Tests; Reciprocating Aircraft Engines § 33.49 Endurance test. (a) General. Each engine must be subjected to an endurance test that includes a total of 150 hours of operation...

  7. Testing of Badminton-Specific Endurance.

    Science.gov (United States)

    Madsen, Christian M; Højlyng, Mads; Nybo, Lars

    2016-09-01

    Madsen, CM, Højlyng, M, and Nybo, L. Testing of badminton-specific endurance. J Strength Cond Res 30(9): 2582-2590, 2016-In the present study, a novel intermittent badminton endurance (B-ENDURANCE) test was developed and tested in elite (n = 17) and skilled (n = 9) badminton players and in age-matched physically active men (nonbadminton players; n = 8). In addition, B-ENDURANCE test-retest reproducibility was evaluated in 9 badminton players. The B-ENDURANCE test is an incremental test where each level consists of repeated sequences of badminton-specific actions toward the 4 corners of the court. The subject starts in the center of the court in front of a computer screen and within each sequence, he must, in a randomized order, complete 8 actions as dictated by the computer, providing the audiovisual input and verifying that the appropriate sensor is activated within the allocated time. Recovery time between each sequence is 10 seconds throughout the test, but the time to complete each sequence is gradually decreased until the subjects cannot follow the dictated tempo. The B-ENDURANCE test performance for elite players was better (p ≤ 0.05) compared with the skilled players and nonbadminton players. In addition, the B-ENDURANCE test performance correlated (r = 0.8 and p badminton-specific endurance but at least 1 familiarization trial is recommended if the test is used for evaluation of longitudinal changes, e.g., tracking training effects.

  8. Endurance test of DUPIC irradiation test rig-003

    Energy Technology Data Exchange (ETDEWEB)

    Moon, J.S; Yang, M.S.; Lee, C.Y.; Ryu, J.S.; Jeon, H.G

    2001-04-01

    This report presents the pressure drop, vibration and endurance test results for DUPIC Irradiation Test Rig-003 which was design and fabricated by KAERI. From the pressure drop and vibration test results, it is verified that DUPIC Irradiation Test Rig-003 satisfied the limit conditions of HANARO. And, remarkable wear is not observed in DUPIC Irradiation Test Rig-003 during 40 endurance test days.

  9. Thermal endurance tests on silicone rubber specimens

    International Nuclear Information System (INIS)

    Warburton, C.

    1977-07-01

    Thermal endurance tests have been performed on a range of silicone rubber specimens at temperature above 300 0 C. It is suggested that the rubber mix A2426, the compound from which Wylfa sealing rings are manufactured, will fail at temperatures above 300 0 C within weeks. Hardness measurements show that this particular rubber performs in a similar manner to Walker's S.I.L./60. (author)

  10. A power recirculating test rig for ball screw endurance tests

    Directory of Open Access Journals (Sweden)

    Giberti Hermes

    2016-01-01

    Full Text Available A conceptual design of an innovative test rig for endurance tests of ball screws is presented in this paper. The test rig layout is based on the power recirculating principle and it also allows to overtake the main critical issues of the ball screw endurance tests. Among these there are the high power required to make the test, the lengthy duration of the same and the high loads between the screw and the frame that holds it. The article describes the test rig designed scheme, the kinematic expedients to be adopted in order to obtain the required performance and functionality and the sizing procedure to choose the actuation system.

  11. Endurance testing with Li/Na electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Ong, E.T.; Remick, R.J.; Sishtla, C.I. [Institute of Gas Technology, Des Plaines, IL (United States)

    1996-12-31

    The Institute of Gas Technology (IGT), under subcontract to M-C Power Corporation under DOE funding, has been operating bench-scale fuel cells to investigate the performance and endurance issues of the Li/Na electrolyte because it offers higher ionic conductivity, higher exchange current densities, lower vapor pressures, and lower cathode dissolution rates than the Li/K electrolyte. These cells have continued to show higher performance and lower decay rates than the Li/K cells since the publication of our two previous papers in 1994. In this paper, test results of two long-term 100-cm{sup 2} bench scale cells are discussed. One cell operated continuously at 160 mA/cm{sup 2} for 17,000 hours with reference gases (60H{sub 2}/20CO{sub 2}/20H{sub 2}O fuel at 75% utilization and 30CO{sub 2}/70 air oxidant humidified at room temperature at 50% utilization). The other cell operated at 160 mA/cm{sup 2} for 6900 hours at 3 atm with system gases (64H{sub 2}/16CO{sub 2}/20H{sub 2}O at 75% utilization and an M-C Power system-defined oxidant at 40% utilization). Both cells have shown the highest performance and longest endurance among IGT cells operated to date.

  12. Facility for endurance tests of thermal insulations

    International Nuclear Information System (INIS)

    Mauersberger, R.

    1984-01-01

    In the following report the design and construction of an experimental facility for endurance tests of thermal insulations is presented. It's name in abbreviation is 'ADI' standing for the German words A nlage zum Dauertest von Isolierungen . This test facility was build by HRB in order to investigate the performance of thermal insulation systems of hot gas ducts for the process heat-reactor-project. The tests are intended to simulate the conditions of reactor operation. They include short-time experiments for selection of insulation-concepts and in a second step long-time experiments as performance tests. During these tests are measured the effective heat conductivity the local heat losses the temperature profiles of the insulation, of the fixing elements and along the wall of the duct. The design-data required to perform all these tasks are shown in the first picture: The gas-atmosphere must be Helium in tests like in reactor with regard to the special thermal and hydraulic properties of Helium and to the influence of Helium on mechanic friction and wear. The hot gas temperature in the PNP-reactor will be 950 deg. C and should be equal in the experiments. The temperature on the cold side of the insulation has to be adjustable from 50 deg. C up to 300 deg. C. The Helium pressure in the hot gas ducts of a HTR-plant is about 42 bar. The ADI was laid out for 70 bar to cover the hole range of interest. A Helium mass flow has to stream through the insulated test duct in order to realize equal temperatures on the hot side of the insulation. A flow rate of 4,5 kg/s is sufficient for this requirement. The axial pressure gradient along the insulation must be the same as in the reactor, because this has an essential influence on the heat losses. This pressure gradient is about 40 Pa/m

  13. Static and Dynamic Handgrip Strength Endurance: Test-Retest Reproducibility.

    Science.gov (United States)

    Gerodimos, Vassilis; Karatrantou, Konstantina; Psychou, Dimitra; Vasilopoulou, Theodora; Zafeiridis, Andreas

    2017-03-01

    This study investigated the reliability of static and dynamic handgrip strength endurance using different protocols and indicators for the assessment of strength endurance. Forty young, healthy men and women (age, 18-22 years) performed 2 handgrip strength endurance protocols: a static protocol (sustained submaximal contraction at 50% of maximal voluntary contraction) and a dynamic one (8, 10, and 12 maximal repetitions). The participants executed each protocol twice to assess the test-retest reproducibility. Total work and total time were used as indicators of strength endurance in the static protocol; the strength recorded at each maximal repetition, the percentage change, and fatigue index were used as indicators of strength endurance in the dynamic protocol. The static protocol showed high reliability irrespective of sex and hand for total time and work. The 12-repetition dynamic protocol exhibited moderate-high reliability for repeated maximal repetitions and percentage change; the 8- and 10-repetition protocols demonstrated lower reliability irrespective of sex and hand. The fatigue index was not a reliable indicator for the assessment of dynamic handgrip endurance. Static handgrip endurance can be measured reliably using the total time and total work as indicators of strength endurance. For the evaluation of dynamic handgrip endurance, the 12-repetition protocol is recommended, using the repeated maximal repetitions and percentage change as indicators of strength endurance. Practitioners should consider the static (50% maximal voluntary contraction) and dynamic (12 repeated maximal repetitions) protocols as reliable for the assessment of handgrip strength endurance. The evaluation of static endurance in conjunction with dynamic endurance would provide more complete information about hand function. Copyright © 2017 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  14. Endurance testing of a WDS catalyst

    International Nuclear Information System (INIS)

    Vladu, Mihaela; Brad, Sebastian; Vijulie, Mihai; Vasut, Felicia; Constantin, Marin

    2007-01-01

    Full text: The Water Detritiation System (WDS) of ITER is a safety related component since it is the final barrier against tritium discharge into the environment. Therefore, its subcomponents have to be qualified and predictions on the time evolution of performances have to be made. During the activities devoted to JET WDS, test at lower concentrations of tritium and at small scale have been performed. The goal of this work is to extend the endurance testings and to check early results by tests under relevant conditions. The degradation of the WDS catalyst can strongly affect its separation performances and consequently it will entail a raise of the tritium releases into the environment. If a catalyst based on Teflon material is used for the LPCE column of WDS, the fluoride that may be formed and released due to the tritium presence causes the corrosion of the LPCE column with unpredictable effects. Therefore the quantification of catalyst degradation and the amount of fluoride released is needed for planning the maintenance activities and to predict the operation life time of the WDS components. The manufacturing of hydrophobic catalysts with activity that is not lowered by liquid water determined the rise of interest for the isotopes separation techniques in the hydrogen - water system. The active component of these catalysts is Pt (the only material to be further discussed) that enhances the exchange between the hydrogen and water vapors. The hydrophobic support does not allow the wetting and blocking by water of the active surface. Hydrophobic catalysts were manufactured by two methods: - direct deposition of Pt into the pores of a hydrophobic support (Teflon, carbon monofluoride, poly styrene, styrene di-vinyl benzene, etc.); - deposition on a hydrophilic support, most common charcoal, followed by hydrophobization by silicon oil or by homogenizing with hydrophobic polymer (Teflon, silicon resins). This type of catalysts is one of the most studied groups due to

  15. CANFLEX fuel bundle cross-flow endurance test (test report)

    International Nuclear Information System (INIS)

    Hong, Sung Deok; Chung, C. H.; Chang, S. K.; Kim, B. D.

    1997-04-01

    As part of the normal refuelling sequence of CANDU nuclear reactor, both new and irradiated bundles can be parked in the cross-flow region of the liner tubes. This situation occurs normally for a few minutes. The fuel bundle which is subjected to the cross-flow should be capable of withstanding the consequences of cross flow for normal periods, and maintain its mechanical integrity. The cross-flow endurance test was conducted for CANFLEX bundle, latest developed nuclear fuel, at CANDU-Hot Test Loop. The test was carried out during 4 hours at the inlet cross-flow region. After the test, the bundle successfully met all acceptance criteria after the 4 hours cross-flow test. (author). 2 refs., 3 tabs

  16. CANFLEX fuel bundle cross-flow endurance test (test report)

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Sung Deok; Chung, C. H.; Chang, S. K.; Kim, B. D.

    1997-04-01

    As part of the normal refuelling sequence of CANDU nuclear reactor, both new and irradiated bundles can be parked in the cross-flow region of the liner tubes. This situation occurs normally for a few minutes. The fuel bundle which is subjected to the cross-flow should be capable of withstanding the consequences of cross flow for normal periods, and maintain its mechanical integrity. The cross-flow endurance test was conducted for CANFLEX bundle, latest developed nuclear fuel, at CANDU-Hot Test Loop. The test was carried out during 4 hours at the inlet cross-flow region. After the test, the bundle successfully met all acceptance criteria after the 4 hours cross-flow test. (author). 2 refs., 3 tabs.

  17. A Field Test for Upper Body Strength and Endurance.

    Science.gov (United States)

    Nelson, Jack K.; And Others

    1991-01-01

    Researchers studied the reliability of the modified push-up test in measuring upper body strength and endurance in elementary through college students. It also examined the accuracy of partner scoring. The test proved much easier to administer than the regular floor push-up. It was valid and reliable for all students and suitable for partner…

  18. Endurance test on IR rig for RI production

    International Nuclear Information System (INIS)

    Chung, Heung June; Youn, Y. J.; Han, H. S.; Hong, S. B.; Cho, Y. G.; Ryu, J. S.

    2000-12-01

    This report presents the pressure drop, vibration and endurance test results for IR rig for RI production which were desigened and fabricated by KAERI. From the pressure drop test results, it is noted that the flow rate through the IR rig corresponding to the pressure drop of 200 kPa is measured to be about 3.12 kg/sec. Vibration frequency for the IR rig ranges from 13 to 17 Hz. RMS(Root Mean Square) displacement for the IR rig is less than 30 μm, and the maximum displacement is less than 110μm. These experimental results show that the design criteria of IR rig meet the HANARO limit conditions. Endurance test results show that the appreciable fretting wear for the IR rig does not occur, however tiny trace of wear between contact points is observed

  19. Analysis of Tests Evaluating Sport Climbers’ Strength and Isometric Endurance

    Directory of Open Access Journals (Sweden)

    Ozimek Mariusz

    2016-12-01

    Full Text Available The present study was designed to determine which types of specific tests provide an effective evaluation of strength and endurance in highly trained competitive sport climbers. The research process consisted of three basic components: the measurement of selected somatic characteristics of the climbers, the assessment of their physical conditioning, and a search for correlations between the anthropometric and “conditioning” variables on the one hand, and climber’s performance on the other. The sample of subjects consisted of 14 experienced volunteer climbers capable of handling 7a- 8a+/b on-sight rock climbing grades. The strongest correlations (Spearman’s rank were found between climber’s competence and the relative results of the finger strength test (r = 0.7; much lower, but still statistically significant coefficients were found between the level of competence and the results of the muscle endurance tests (r = 0.53 – 0.57. Climbers aspiring to attain an elite level must have strong finger and forearm muscles, but most of all, they must be capable of releasing their potential during specific motor capability tests engaging these parts of the body. The forearm muscles of elite climbers must also be very resistant to fatigue. Since highly trained athletes vary only slightly in body mass, this variable does not have a major effect on their performance during strength and endurance tests.

  20. Validity, Reliability, and Sensitivity of a Volleyball Intermittent Endurance Test.

    Science.gov (United States)

    Rodríguez-Marroyo, Jose A; Medina-Carrillo, Javier; García-López, Juan; Morante, Juan C; Villa, José G; Foster, Carl

    2017-03-01

    To analyze the concurrent and construct validity of a volleyball intermittent endurance test (VIET). The VIET's test-retest reliability and sensitivity to assess seasonal changes was also studied. During the preseason, 71 volleyball players of different competitive levels took part in this study. All performed the VIET and a graded treadmill test with gas-exchange measurement (GXT). Thirty-one of the players performed an additional VIET to analyze the test-retest reliability. To test the VIET's sensitivity, 28 players repeated the VIET and GXT at the end of their season. Significant (P volleyball players.

  1. Endurance test for IR rig for RI production assembly (test procedure)

    International Nuclear Information System (INIS)

    Chung, Heung June; Ryu, Jeong Soo

    2000-08-01

    This test procedure details the test loop, test method, and test procedure for pressure drop, vibration and endurance test of IR Rig for RI production. From the pressure drop test, the hydraulic design requirements of the capsule are verified. HANARO limit condition is checked and the compatibility with HANARO core is verified. From flow induced vibration test vibration frequency and displacement are investigated. The wear of IR Rig is investigated through endurance test, and these data are used to evaluate the expected wear at maximum resident time of the IR Rig for RI production

  2. Vibration test and endurance test for HANARO 36-element fuel assembly

    International Nuclear Information System (INIS)

    Ryu, Jeong Soo; Kim, Heon ll; Chung, Heung June

    1998-06-01

    Vibration test and endurance test for HANARO DU (depleted uranium) 36-element fuel assembly which was fabricated by KAERI were carried out based on the HANARO operation conditions. The endurance test of 22 days was added to the previous 18 days test. The vibration test was performed at various flow rates. Vibration frequency for the 36-element fuel assembly is between 11 to 14.5 Hz. And the maximum vibration displacement is less than 100 μm. From the endurance test result, it can be concluded that the appreciable fretting wear for the 36-element fuel assembly and the hexagonal flow tube was not observed. (author). 4 refs., 5 tabs., 29 figs

  3. Endurance Pump Test with MIL-PRF-83282 Hydraulic Fluid, Purified with Malabar Purifier

    National Research Council Canada - National Science Library

    Sharma, Shashi

    2004-01-01

    .... Endurance aircraft hydraulic pump tests under carefully controlled conditions were previously conducted using hydraulic fluid purified with a rotating-disk and vacuum type purifier, the portable...

  4. Endurance Test and Evaluation of Alkaline Water Electrolysis Cells

    Science.gov (United States)

    Kovach, Andrew J.; Schubert, Franz H.; Chang, B. J.; Larkins, Jim T.

    1985-01-01

    The overall objective of this program is to assess the state of alkaline water electrolysis cell technology and its potential as part of a Regenerative Fuel Cell System (RFCS) of a multikilowatt orbiting powerplant. The program evaluates the endurance capabilities of alkaline electrolyte water electrolysis cells under various operating conditions, including constant condition testing, cyclic testing and high pressure testing. The RFCS demanded the scale-up of existing cell hardware from 0.1 sq ft active electrode area to 1.0 sq ft active electrode area. A single water electrolysis cell and two six-cell modules of 1.0 sq ft active electrode area were designed and fabricated. The two six-cell 1.0 sq ft modules incorporate 1.0 sq ft utilized cores, which allow for minimization of module assembly complexity and increased tolerance to pressure differential. A water electrolysis subsystem was designed and fabricated to allow testing of the six-cell modules. After completing checkout, shakedown, design verification and parametric testing, a module was incorporated into the Regenerative Fuel Cell System Breadboard (RFCSB) for testing at Life Systems, Inc., and at NASA JSC.

  5. Critical evaluation of a badminton-specific endurance test.

    Science.gov (United States)

    Fuchs, Michael; Faude, Oliver; Wegmann, Melissa; Meyer, Tim

    2014-03-01

    To overcome the limitations of traditional 1-dimensional fitness tests in analyzing physiological properties of badminton players, a badminton-specific endurance test (BST) was created. This study aimed at analyzing the influence of various fitness dimensions on BST performance. 18 internationally competing male German badminton players (22.4 ± 3.2 y, 79.2 ± 7.7 kg, 1.84 ± 0.06 m, world-ranking position [WRP] 21-501) completed a straight-sprint test, a change-of-direction speed test, various jump tests (countermovement jump, drop jump, standing long jump), a multistage running test (MST), and the BST. During this on-court field test players have to respond to a computerized sign indicating direction and speed of badminton-specific movements by moving into the corresponding corners. Significant correlations were found between performance in MST and BST (individual anaerobic threshold [IAT], r = .63, P = .005; maximum velocity [Vmax], r = .60, P = .009). A negative correlation (r = -.59, P = .014) was observed between IAT in BST and drop-jump contact time. No further associations between performance indices could be detected. Apart from a small portion explained by MST results (IAT, R2 = .40; Vmax, R2 = .36), the majority of BST performance cannot be explained by the determined physiological correlates. Moreover, it was impossible to predict the WRP of a player on the basis of BST results (r = -.15, P = .55). Neither discipline-specific performance nor basic physiological properties were appropriately reflected by a BST in elite badminton players. This does not substantiate its validity for regular use as a testing tool. However, it may be useful for monitoring on-court training sessions.

  6. Endurance test and evaluation of alkaline water electrolysis cells

    Science.gov (United States)

    Burke, K. A.; Schubert, F. H.

    1981-01-01

    Utilization in the development of multi-kW low orbit power systems is discussed. The following technological developments of alkaline water electrolysis cells for space power application were demonstrated: (1) four 92.9 cm2 single water electrolysis cells, two using LST's advanced anodes and two using LST's super anodes; (2) four single cell endurance test stands for life testing of alkaline water electrolyte cells; (3) the solid performance of the advanced electrode and 355 K; (4) the breakthrough performance of the super electrode; (5) the four single cells for over 5,000 hours each significant cell deterioration or cell failure. It is concluded that the static feed water electrolysis concept is reliable and due to the inherent simplicity of the passive water feed mechanism coupled with the use of alkaline electrolyte has greater potential for regenerative fuel cell system applications than alternative electrolyzers. A rise in cell voltage occur after 2,000-3,000 hours which was attributed to deflection of the polysulfone end plates due to creepage of the thermoplastic. More end plate support was added, and the performance of the cells was restored to the initial performance level.

  7. The sit up test to exhaustion as a test for muscular endurance evaluation.

    Science.gov (United States)

    Bianco, Antonino; Lupo, Corrado; Alesi, Marianna; Spina, Serena; Raccuglia, Margherita; Thomas, Ewan; Paoli, Antonio; Palma, Antonio

    2015-01-01

    The aim of this study was to examine the sit up test to exhaustion as a field test for muscular endurance evaluation in a sample of sedentary people of both sexes. A cross-sectional study was performed. Three-hundred-eighty-one participants volunteered for the study (28.5 ± 10.0 years; 168.2 ± 8.9 cm; 65.1 ± 11.1 kg), of which 194 males (27.5 ± 10.2 years; 173.6 ± 7.0 cm; 71.2 ± 5.2 kg) and 187 females (29.6 ± 10.1 years; 162.6 ± 7.1 cm; 58.7 ± 8.9 kg). Each subject voluntarily and randomly performed: a sit up test (SUT), a push up test (PUT), and a free weight squat test (ST), all till exhaustion. A multiple regression analysis was adopted for data analysis. Subsequently a percentile model for muscle endurance was developed. The 25th, 50th, and 75th percentile were identified as upper limit for low muscular endurance, average muscular endurance, and lower limit for high muscular endurance, respectively. Considering the sit up test as the dependent variable, the coefficients (R(2) = 0.23; r = 0.49; p squat test, respectively. Gender stratification showed regression coefficients of (R(2) = 0.19; r = 0.44; p < 0.001) for SUT vs. PUT, and (R(2) = 0.30; r = 0.56; p < 0.001) for SUT vs. ST in male; and (R(2) = 0.23; r = 0.49; p < 0.001) for SUT vs. PUT, and (R(2) = 0.34; r = 0.59; p < 0.001) for SUT vs. ST in female. The SUT showed low inter-relation with the other proposed tests indicating that the adoption of a single test for the global evaluation of muscle endurance is not the optimal approach. Moreover, the SUT was found to be inexpensive, safe, and appropriate for core muscle endurance measurement for both male and female.

  8. Isokinetic Strength and Endurance Tests used Pre- and Post-Spaceflight: Test-Retest Reliability

    Science.gov (United States)

    Laughlin, Mitzi S.; Lee, Stuart M. C.; Loehr, James A.; Amonette, William E.

    2009-01-01

    To assess changes in muscular strength and endurance after microgravity exposure, NASA measures isokinetic strength and endurance across multiple sessions before and after long-duration space flight. Accurate interpretation of pre- and post-flight measures depends upon the reliability of each measure. The purpose of this study was to evaluate the test-retest reliability of the NASA International Space Station (ISS) isokinetic protocol. Twenty-four healthy subjects (12 M/12 F, 32.0 +/- 5.6 years) volunteered to participate. Isokinetic knee, ankle, and trunk flexion and extension strength as well as endurance of the knee flexors and extensors were measured using a Cybex NORM isokinetic dynamometer. The first weekly session was considered a familiarization session. Data were collected and analyzed for weeks 2-4. Repeated measures analysis of variance (alpha=0.05) was used to identify weekly differences in isokinetic measures. Test-retest reliability was evaluated by intraclass correlation coefficients (ICC) (3,1). No significant differences were found between weeks in any of the strength measures and the reliability of the strength measures were all considered excellent (ICC greater than 0.9), except for concentric ankle dorsi-flexion (ICC=0.67). Although a significant difference was noted in weekly endurance measures of knee extension (p less than 0.01), the reliability of endurance measure by week were considered excellent for knee flexion (ICC=0.97) and knee extension (ICC=0.96). Except for concentric ankle dorsi-flexion, the isokinetic strength and endurance measures are highly reliable when following the NASA ISS protocol. This protocol should allow accurate interpretation isokinetic data even with a small number of crew members.

  9. Tests for predicting endurance kayak performance | Olivier | South ...

    African Journals Online (AJOL)

    Methods : The following variables were measured on 23 competitive endurance kayakers, who provided written informed consent : Arm crank VO2 peak; 1 minute dips; armspan; modified sit-and-reach; grip strength; body mass; height. These were selected on the basis of their being identified as possibly contributing to ...

  10. CANFLEX fuel bundle cross-flow endurance test 2 (Test report)

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Sung Deok; Chung, C. H.; Chang, S. K.; Kim, B. D. [Korea Atomic Energy Research Institute, Taejeon (Korea)

    2000-02-01

    This report describes cross-flow endurance test 2 that was conducted at the CANDU-Hot Test Loop. The test was completed on March 30, 1999 using a new CANFLEX bundle, built by KAERI. It was carried out for a total of 22 hours. After an initial period of ten hours, the test was stopped at the intervals of four hours for bundle inspection and inter-element gap measurement[7]. The test bundle end-plate to end-cap welds were inspected carefully for failure or crack propagation using liquid penetrant examination especially at the heat-affected zones. 12 refs., 4 figs., 10 tabs. (Author)

  11. Endurance Pump Tests With Fresh and Purified MIL-PRF-83282 Hydraulic Fluid

    National Research Council Canada - National Science Library

    Sharma, Shashi

    1999-01-01

    .... Two endurance pump tests were conducted with F-16 aircraft hydraulic pumps, using both fresh and purified MIL-PRF-83282 hydraulic fluid, to determine if fluid purification had any adverse effect on pump life...

  12. Mobility limitation in self-described well-functioning older adults : importance of endurance walk testing

    NARCIS (Netherlands)

    Simonsick, Eleanor M; Newman, Anne B; Visser, Marjolein; Goodpaster, Bret; Kritchevsky, Stephen B; Rubin, Susan; Nevitt, Michael C; Harris, Tamara B

    BACKGROUND: Mobility limitations are prevalent, potentially reversible precursors to mobility loss that may go undetected in older adults. This study evaluates standardized administration of an endurance walk test for identifying unrecognized and impending mobility limitation in community elders.

  13. The assisted 6-minute cycling test to assess endurance in children with a neuromuscular disorder

    NARCIS (Netherlands)

    Jansen, M.; Jong, M. de; Coes, H.M.; Eggermont, F.; Alfen, N. van; de Groot, I.J.

    2012-01-01

    Introduction: For late- or non-ambulant children with a neuromuscular disorder no suitable endurance tests are currently available. We developed the assisted 6-minute cycling test (A6MCT) for the legs and arms and investigated its psychometric properties in healthy boys and boys with Duchenne

  14. Sport-specific endurance plank test for evaluation of global core muscle function.

    Science.gov (United States)

    Tong, Tom K; Wu, Shing; Nie, Jinlei

    2014-02-01

    To examine the validity and reliability of a sports-specific endurance plank test for the evaluation of global core muscle function. Repeated-measures study. Laboratory environment. Twenty-eight male and eight female young athletes. Surface electromyography (sEMG) of selected trunk flexors and extensors, and an intervention of pre-fatigue core workout were applied for test validation. Intraclass correlation coefficient (ICC), coefficient of variation (CV), and the measurement bias ratio */÷ ratio limits of agreement (LOA) were calculated to assess reliability and measurement error. Test validity was shown by the sEMG of selected core muscles, which indicated >50% increase in muscle activation during the test; and the definite discrimination of the ∼30% reduction in global core muscle endurance subsequent to a pre-fatigue core workout. For test-retest reliability, when the first attempt of three repeated trials was considered as familiarisation, the ICC was 0.99 (95% CI: 0.98-0.99), CV was 2.0 ± 1.56% and the measurement bias ratio */÷ ratio LOA was 0.99 */÷ 1.07. The findings suggest that the sport-specific endurance plank test is a valid, reliable and practical method for assessing global core muscle endurance in athletes given that at least one familiarisation trial takes place prior to measurement. Copyright © 2013 Elsevier Ltd. All rights reserved.

  15. Reliability of ultrasound thickness measurement of the abdominal muscles during clinical isometric endurance tests.

    Science.gov (United States)

    ShahAli, Shabnam; Arab, Amir Massoud; Talebian, Saeed; Ebrahimi, Esmaeil; Bahmani, Andia; Karimi, Noureddin; Nabavi, Hoda

    2015-07-01

    The study was designed to evaluate the intra-examiner reliability of ultrasound (US) thickness measurement of abdominal muscles activity when supine lying and during two isometric endurance tests in subjects with and without Low back pain (LBP). A total of 19 women (9 with LBP, 10 without LBP) participated in the study. Within-day reliability of the US thickness measurements at supine lying and the two isometric endurance tests were assessed in all subjects. The intra-class correlation coefficient (ICC) was used to assess the relative reliability of thickness measurement. The standard error of measurement (SEM), minimal detectable change (MDC) and the coefficient of variation (CV) were used to evaluate the absolute reliability. Results indicated high ICC scores (0.73-0.99) and also small SEM and MDC scores for within-day reliability assessment. The Bland-Altman plots of agreement in US measurement of the abdominal muscles during the two isometric endurance tests demonstrated that 95% of the observations fall between the limits of agreement for test and retest measurements. Together the results indicate high intra-tester reliability for the US measurement of the thickness of abdominal muscles in all the positions tested. According to the study's findings, US imaging can be used as a reliable method for assessment of abdominal muscles activity in supine lying and the two isometric endurance tests employed, in participants with and without LBP. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Literature review Quasi-static and Dynamic pile load tests : Primarily report on non-static pile load tests

    NARCIS (Netherlands)

    Huy, N.Q.

    2010-01-01

    Pile testing, which plays an importance role in the field of deep foundation design, is performed by static and non-static methods to provide information about the following issues: (Poulos, 1998) - The ultimate capacity of a single pile. - The load-displacement behavior of a pile. - The performance

  17. Reproducibility of an aerobic endurance test for nonexpert swimmers.

    Science.gov (United States)

    Veronese da Costa, Adalberto; Costa, Manoel da Cunha; Carlos, Daniel Medeiros; Guerra, Luis Marcos de Medeiros; Silva, Antônio José; Barbosa, Tiago Manoel Cabral Dos Santos

    2012-01-01

    This study aimed to verify the reproduction of an aerobic test to determine nonexpert swimmers' resistance. The sample consisted of 24 male swimmers (age: 22.79 ± 3.90 years; weight: 74.72 ± 11.44 kg; height: 172.58 ± 4.99 cm; and fat percentage: 15.19% ± 3.21%), who swim for 1 hour three times a week. A new instrument was used in this study (a Progressive Swim Test): the swimmer wore an underwater MP3 player and increased their swimming speed on hearing a beep after every 25 meters. Each swimmer's heart rate was recorded before the test (BHR) and again after the test (AHR). The rate of perceived exertion (RPE) and the number of laps performed (NLP) were also recorded. The sample size was estimated using G*Power software (v 3.0.10; Franz Faul, Kiel University, Kiel, Germany). The descriptive values were expressed as mean and standard deviation. After confirming the normality of the data using both the Shapiro-Wilk and Levene tests, a paired t-test was performed to compare the data. The Pearson's linear correlation (r) and intraclass coefficient correlation (ICC) tests were used to determine relative reproducibility. The standard error of measurement (SEM) and the coefficient of variation (CV) were used to determine absolute reproducibility. The limits of agreement and the bias of the absolute and relative values between days were determined by Bland-Altman plots. All values had a significance level of P 0.50 and ICC > 0.66. The SEM had a variation of ±2% and the CV was 0.90; SEM swimmers. The Progressive Swim Test for nonexpert swimmers produces comparable results for noncompetitive swimmers with a favorable degree of reproducibility, thus presenting possible applications for researching the physiological performance of nonexpert swimmers.

  18. Associations of maximal strength and muscular endurance test scores with cardiorespiratory fitness and body composition.

    Science.gov (United States)

    Vaara, Jani P; Kyröläinen, Heikki; Niemi, Jaakko; Ohrankämmen, Olli; Häkkinen, Arja; Kocay, Sheila; Häkkinen, Keijo

    2012-08-01

    The purpose of the present study was to assess the relationships between maximal strength and muscular endurance test scores additionally to previously widely studied measures of body composition and maximal aerobic capacity. 846 young men (25.5 ± 5.0 yrs) participated in the study. Maximal strength was measured using isometric bench press, leg extension and grip strength. Muscular endurance tests consisted of push-ups, sit-ups and repeated squats. An indirect graded cycle ergometer test was used to estimate maximal aerobic capacity (V(O2)max). Body composition was determined with bioelectrical impedance. Moreover, waist circumference (WC) and height were measured and body mass index (BMI) calculated. Maximal bench press was positively correlated with push-ups (r = 0.61, p strength (r = 0.34, p strength correlated positively (r = 0.36-0.44, p test scores were related to maximal aerobic capacity and body fat content, while fat free mass was associated with maximal strength test scores and thus is a major determinant for maximal strength. A contributive role of maximal strength to muscular endurance tests could be identified for the upper, but not the lower extremities. These findings suggest that push-up test is not only indicative of body fat content and maximal aerobic capacity but also maximal strength of upper body, whereas repeated squat test is mainly indicative of body fat content and maximal aerobic capacity, but not maximal strength of lower extremities.

  19. Reproducibility of an aerobic endurance test for nonexpert swimmers

    Directory of Open Access Journals (Sweden)

    Veronese da Costa A

    2012-09-01

    Full Text Available Adalberto Veronese da Costa,1,2 Manoel da Cunha Costa,3 Daniel Medeiros Carlos,1 Luis Marcos de Medeiros Guerra,1,2 Antônio José Silva,2 Tiago Manoel Cabral dos Santos Barbosa2,41Department of Physical Education, Bioscience Laboratory of Human Kinetics, Rio Grande do Norte State University, Mossoró, Brazil; 2Sport Sciences Trás-os-Montes e Alto Douro University, Research Center in Sport, Health and Human Development, Vila Real, Portugal; 3Superior School of Physical Education, Human Performance Laboratory, Pernambuco State University, Recife, Brazil; 4National Institute of Education, Nanyang Technological University, SingaporeBackground: This study aimed to verify the reproduction of an aerobic test to determine nonexpert swimmers' resistance.Methods: The sample consisted of 24 male swimmers (age: 22.79 ± 3.90 years; weight: 74.72 ± 11.44 kg; height: 172.58 ± 4.99 cm; and fat percentage: 15.19% ± 3.21%, who swim for 1 hour three times a week. A new instrument was used in this study (a Progressive Swim Test: the swimmer wore an underwater MP3 player and increased their swimming speed on hearing a beep after every 25 meters. Each swimmer's heart rate was recorded before the test (BHR and again after the test (AHR. The rate of perceived exertion (RPE and the number of laps performed (NLP were also recorded. The sample size was estimated using G*Power software (v 3.0.10; Franz Faul, Kiel University, Kiel, Germany. The descriptive values were expressed as mean and standard deviation. After confirming the normality of the data using both the Shapiro–Wilk and Levene tests, a paired t-test was performed to compare the data. The Pearson's linear correlation (r and intraclass coefficient correlation (ICC tests were used to determine relative reproducibility. The standard error of measurement (SEM and the coefficient of variation (CV were used to determine absolute reproducibility. The limits of agreement and the bias of the absolute and relative

  20. Results of the 1000 Hour Rotary Microfilter Endurance Test

    International Nuclear Information System (INIS)

    Herman, D.

    2010-01-01

    During operation, a primary concern is lifetime of the mechanical seal. Leakage from main shaft mechanical seal is expected to be first indication of wear on rotary filter but will not be the ultimate failure of the filter. Initial clearance inadequate to support thermal expansion resulted in initial scarring of journal. Tolerances adjusted and no journal issues were found during 1000 hour test. Disassembly and inspection of the rotary joint seals showed no unusual wear. No leakage observed during test. Total operation time over 1500 hours. Test summary successfully demonstrated: (1) Filtration of a 'challenging' SRS simulant up to 15 wt % insoluble solids in a 5.6 M salt simulant; (2) Sludge washing; (3) In-situ acid cleaning with dilute acid; (4) Over 1000 hours of operation on new journal material; and (5) Over 1500 hours of operation on all seals. The filter out lasted: 2 air compressors, 2 power outages (one planned), 2 chillers, 1 fire, 1 electrical breaker and 1 feed pump seal.

  1. Shattered: Medawar's test tubes and their enduring legacy of chaos.

    Science.gov (United States)

    Bowles, J

    2000-02-01

    Medawar's 1952 paper 'An Unsolved Problem of Biology' underlies most subsequent theoretical work regarding the evolution of aging; it concludes that aging is accidental and could not have evolved; this prevents reconciling the growing body of evidence suggesting the existence of multiple, evolved, aging systems. The paper features a well-known thought experiment using test tubes to show why aging could not evolve. Medawar assumes that constant, random, breakage sufficiently represents lethal forces of nature; however, famine, drought, predation, disease, and accidents each uniquely affect populations. Predation is the only evolving force that continually invents new ways to kill members of the prey populations; thus all prey defenses to predation will eventually be defeated. Defenses to non-evolving or non-obligate lethal forces, however, should quickly evolve. Thus unevolving, identical test tubes cannot adequately represent biological populations. The example also ignores population booms and busts which often occur in nature. By ignoring these issues, Medawar examines only one population age distribution skewed towards younger individuals in predator-dominated environments while ignoring predator-free populations skewed towards older individuals after population crashes. Further, Medawar's test tubes lack meaningful competition for finite resources, and ignore declining fertility which occurs in all aging species. Medawar concludes that older individuals are too few in number to influence the population's gene pool for or against aging. This conclusion is found to be incorrect when variations in the age of reproductive senescence are introduced into a predator-free population.A new thought experiment with competing strains of algae corrects for these issues and shows that aging evolved and is retained so that groups retain enough genetic variability to allow for rapid evolution of a defense to novel predation. The example shows reasons why the rate of aging is

  2. Free-piston Stirling engine/linear alternator 1000-hour endurance test

    Science.gov (United States)

    Rauch, J.; Dochat, G.

    1985-01-01

    The Free Piston Stirling Engine (FPSE) has the potential to be a long lived, highly reliable, power conversion device attractive for many product applications such as space, residential or remote site power. The purpose of endurance testing the FPSE was to demonstrate its potential for long life. The endurance program was directed at obtaining 1000 operational hours under various test conditions: low power, full stroke, duty cycle and stop/start. Critical performance parameters were measured to note any change and/or trend. Inspections were conducted to measure and compare critical seal/bearing clearances. The engine performed well throughout the program, completing more than 1100 hours. Hardware inspection, including the critical clearances, showed no significant change in hardware or clearance dimensions. The performance parameters did not exhibit any increasing or decreasing trends. The test program confirms the potential for long life FPSE applications.

  3. Energy Monitoring and Control Systems--Performance Verification and Endurance Test Procedures.

    Science.gov (United States)

    1982-12-01

    EM-; tK2 s) trave h.en loadted in qvstem sit ~rp sm:l , o,1 ti-’.~ -1 rouiitthe factoz’, lest. E.VEF.NT Comnmwid the system to display the status of...contractor correction of all outstanding deficiencies . 163 TEST NO: END-i Page I of 1 OBJECTIVE: To demonstrate EMCS normal mode operation 24 TITLE: Endurance

  4. Reliability of Arm Curl and Chair Stand tests for assessing muscular endurance in older people

    Directory of Open Access Journals (Sweden)

    Boneth M

    2012-05-01

    Full Text Available Objective: to assess the test-retest reliability and level of agreement between measures of the 30 second (30-s Arm Curl and 30-s Chair Stand test in a sample of older adults from Bucaramanga. Materials and methods: a study of evaluation of diagnostic technology was done. Both tests were administered by the same evaluator to 111 adults older than 59 year-old (70,4 ± 7,3, on two occasions, with an interval of time between measures of 4 to 8 days. In the analysis, test-retest reliability was determined using the Intraclass Correlation Coefficient ICC= 2,1 with their confidence interval 95% (CI 95% respective. The agreement level was established by the Bland and Altman method. Results: the test-retest reproducibility of the 30-s Arm Curl test was very good ICC= 0,88 and to the Chair Stand test was good ICC= 0,78. The agreement was very good for both tests of muscle endurance. The CI 95% were between -3,8 and 3,2 stands to 30-s Chair Stand test and between -3,1 and 2,8 curls to 30-s Arm Curl test. Conclusion: the 30-s Arm Curl and 30-s Chair Stand test have good reliability and agreement to assess muscle endurance in older adults functionally independent.

  5. Hand grip endurance test relates to clinical state and prognosis in COPD patients better than 6-minute walk test distance

    Directory of Open Access Journals (Sweden)

    Kovarik M

    2017-12-01

    Full Text Available Miroslav Kovarik,1,2 Vera Joskova,1,2 Anna Patkova,1,2 Vladimir Koblizek,3 Zdenek Zadak,2 Miloslav Hronek1,2 1Department of Biological and Medical Sciences, Faculty of Pharmacy in Hradec Kralove, Charles University, Hradec Kralove, Czech Republic; 2Department of Research and Development, University Hospital Hradec Kralove, Hradec Kralove, Czech Republic; 3Department of Pulmonary Medicine, University Hospital Hradec Kralove, Hradec Kralove, Czech Republic Purpose: Patients with COPD present peripheral muscle dysfunction and atrophy, expressed as muscle strength and endurance reduction. The goal of this study was direct dynamometric assessment of hand grip endurance and strength in relation to the stage of disease, multidimensional predictors of mortality, and 6-minute walk test (6MWT. To the best of our knowledge, there has been no previous study determining these parameters.Patients and methods: In this observational study, 58 consecutive outpatients with stable COPD and 25 volunteers without respiratory problems were compared. All COPD subjects underwent a comprehensive examination to determine COPD severity, prognostic scales, and 6MWT. Body composition, basic spirometric parameters, and hand grip strength and endurance were determined in all study participants.Results: Patients in the COPD group had a 15% decrease in maximum strength (P=0.012 and a 28% decrease in area under the force/time curve (AUC of the endurance test (P<0.001 compared to the control group. Dynamometric parameters were significantly negatively associated with the stage of disease and values of multivariable prediction indexes, and positively associated with the results of 6MWT. In most cases, closer associations were found with AUC than with 6MWT and in the gender-specific groups.Conclusion: Both hand grip strength and endurance are impaired in COPD patients in comparison with the control group. In particular, AUC could be considered as an attractive option not only to

  6. Real-time and accelerated outdoor endurance testing of solar cells

    Science.gov (United States)

    Forestieri, A. F.; Anagnostou, E.

    1977-01-01

    Real-time and accelerated outdoor endurance testing was performed on a variety of samples of interest to the National Photovoltaic Conversion Program. The real-time tests were performed at seven different sites and the accelerated tests were performed at one of those sites in the southwestern United States. The purpose of the tests were to help evaluate the lifetime of photovoltaic systems. Three types of samples were tested; transmission samples of possible cover materials, sub-modules constructed using these materials attached to solar cells, and solar cell modules produced by the manufacturers for the ERDA program. Results indicate that suitable cover materials are glass, FEP-A and PFA. Dirt accumulation and cleanability are important factors in the selection of solar cell module covers and encapsulants.

  7. Development of Stepping Endurance Test Plan on CRDM of a Research Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kim, DongHyun; Kim, Hyeonil; Park, Suki [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    Various types of the irradiation targets can be loaded and unloaded during power operation, according to the purpose of research reactor utilization. And their reactivity worth varies as well. The insertion rate of reactivity is dependent to reactivity worth of targets, travel length during loading or unloading and transfer device speed. Due to the reactivity transition during loading and unloading, neutron power is changed and reaches an action point of the reactor regulating system. Based on the measured neutron rate of change, reactor power control system controls the power with its own algorithm. It generates the signals and transmits these to the CRDM for motor driving. Stepping motors on the CRDM move the control rods with step signals. The process repeats until power is stabilized. Accordingly, the stepping behaviours of CRDM should be modelled upon an understanding of the control process and reactor responses. Methodology for a stepping endurance test plan on the CRDM of a research reactor is developed since CRDM endurance is very important for reactor controller and should be ensured for a certain period of time throughout the life of a research reactor. Therefore, it is expected to provide a reasonable stepping test plan. In the future, the simulation will be performed with specific design values.

  8. The Impact of Listening to Music During a High-Intensity Exercise Endurance Test in People With COPD.

    Science.gov (United States)

    Lee, Annemarie L; Dolmage, Thomas E; Rhim, Matthew; Goldstein, Roger S; Brooks, Dina

    2018-05-01

    In people with COPD, dyspnea is the primary symptom limiting exercise tolerance. One approach to reducing dyspnea during exercise is through music listening. A constant speed endurance test reflects a high-intensity aerobic exercise training session, but whether listening to music affects endurance time is unknown. This study aimed to determine the effects of listening to music during a constant speed endurance test in COPD. Participants with COPD completed two endurance walk tests, one with and one without listening to self-selected music throughout the test. The primary outcome was the difference in endurance time between the two conditions. Heart rate, percutaneous oxygen saturation, dyspnea, and rate of perceived exertion were measured before and after each test. Nineteen participants (mean [SD]: age, 71 [8] years; FEV 1 , 47 [19] % predicted) completed the study. Endurance time was greater (1.10 [95% CI, 0.41-1.78] min) while listening to music (7.0 [3.1] min) than without (5.9 [2.6] min), and reduced end-test dyspnea (1.0 [95% CI, -2.80 to -1.80] units) (with music, 4.6 [1.7] units; vs without music, 5.6 [1.4] units, respectively). There was not a significant difference in heart rate, percutaneous oxygen saturation, or leg fatigue. There were no adverse events under either condition. In COPD, dyspnea was less while listening to music and was accompanied by an increased tolerance of high-intensity exercise demonstrated by greater endurance time. Practically, the effect was modest but may represent an aid for exercise training of these patients. Australian New Zealand Clinical Trials Registry; No. ACTRN12617001217392. Copyright © 2017 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

  9. SUPER-CAPACITOR APPLICATION IN ELECTRICAL POWER CABLE TESTING FACILITIES IN THERMAL ENDURANCE AND MECHANICAL BRACING TESTS

    Directory of Open Access Journals (Sweden)

    I. V. Oleksyuk

    2015-01-01

    Full Text Available The current-carrying cores of the electrical power cables should be resistant to effects of short-circuit currents whose values depend on the material of the core, its cross-sectional area, cable insulation properties, environment temperature, and the duration of the short-circuit current flow (1 and 3–4 sec. when tested for thermal endurance and mechanical bracing. The facilities for testing the 10 kV aluminum core cables with short-circuit current shall provide mechanical-bracing current 56,82 kA and thermal endurance current 11,16 kA. Although capacitors provide such values of the testing currents to the best advantage, utilizing conventional capacitor-units will involve large expenditures for erecting and  running a separate building. It is expedient to apply super-capacitors qua the electric power supply for testing facilities, as they are capacitors with double-electrical layer and involve the current values of tens of kilo-amperes.The insulation voltage during short-circuit current testing being not-standardized, it is not banned to apply voltages less than 10 kV when performing short-circuit thermal endurance and mechanical bracing tests for electrical power cables of 10 kV. The super-capacitor voltage variation-in-time graph consists of two regions: capacitive and resistive. The capacitive part corresponds to the voltage change consequent on the energy change in the super-capacitors. The resistive part shows the voltage variation due to the active resistance presence in the super-capacitor.The author offers the algorithm determining the number of super capacitors requisite for testing 10 kV-electrical power cables with short-circuit currents for thermal endurance and mechanical bracing. The paper shows that installation of super-capacitors in the facilities testing the cables with short-circuit currents reduces the area needed for the super-capacitors in comparison with conventional capacitors more than by one order of magnitude.

  10. Estimating the Contact Endurance of the AISI 321 Stainless Steel Under Contact Gigacycle Fatigue Tests

    Science.gov (United States)

    Savrai, R. A.; Makarov, A. V.; Osintseva, A. L.; Malygina, I. Yu.

    2018-02-01

    Mechanical testing of the AISI 321 corrosion resistant austenitic steel for contact gigacycle fatigue has been conducted with the application of a new method of contact fatigue testing with ultrasonic frequency of loading according to a pulsing impact "plane-to-plane" contact scheme. It has been found that the contact endurance (the ability to resist the fatigue spalling) of the AISI 321 steel under contact gigacycle fatigue loading is determined by its plasticity margin and the possibility of additional hardening under contact loading. It is demonstrated that the appearance of localized deep and long areas of spalling on a material surface can serve as a qualitative characteristic for the loss of the fatigue strength of the AISI 321 steel under impact contact fatigue loading. The value of surface microhardness measured within contact spots and the maximum depth of contact damages in the peripheral zone of contact spots can serve as quantitative criteria for that purpose.

  11. Validity and Reliability of Curl-Up Test on Assessing the Core Endurance for Kindergarten Children in Hong Kong

    OpenAIRE

    Lai, CY; Lee, KY; Lams, MHS; Wu, CF; Peake, R; Flint, SW; Li, WHC; Ho, E

    2017-01-01

    Objective: The purpose of this study was to examine the test-retest reliability and the criterion validity of a curlup\\ud test (CUT) as a measure of core stability, core endurance and dynamic stability in kindergarten children. CUT\\ud performance was also compared to half hold lying test (HHLT) and walking time on course (WTC) among without\\ud obstacle, with low obstacle and high obstacle measures of core stability, core endurance and dynamic stability.\\ud Methods: To estimate reliability, 33...

  12. Comparison between two motor tests used for muscular strength/endurance analysis

    Directory of Open Access Journals (Sweden)

    Matheus Amarante do Nascimento

    2013-04-01

    Full Text Available The aim of this study was to compare motor performance in modified pull-up (MPUand flexed knee push-up (FKPU tests in young women. Thirty-five apparently healthy women (20.1±2.2 years were submitted to each one of the tests at an interval of48 hours in a random balanced design. Most individuals performed between 0 an d 10 repetitions (86% of the MPU test, and approximately 17% did not perform even one repetitions. On the other hand, the highest prevalence of outcomes for the FKPUtest was between 16 and 35 repetitions (71%. The Wilcoxon test identified statistically significant differences (p MPU. A moderate agreement (kappa =0.40 was found between the performance in both tests. Negative correlations of low magnitude (r=-0.23 to 0.46 were found between morphological variables (body weight,height, fat mass, and lean body mass and motor performance in both tests. The results suggest that the FKPU test is presented as a better indicator ofmuscular endurance levels, where as the MPU test seems to better discriminate muscular strength in young women.

  13. Back extensor muscle endurance test scores in coal miners in Australia

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, M.; Latimer, J.; Jamieson, M. [University of Sydney, Sydney, NSW (Australia). Faculty of Health and Science, School of Physiotherapy

    2003-06-01

    Low back pain is a common complaint among those working in the Australian coal mining industry. One test that may be predictive of first-time episodes of low back pain is the Biering-Sorensen test of back extensor endurance strength. While this test has been evaluated in overseas sedentary populations, normative data and the discriminative ability of the test have not been evaluated with coal miners. Eighty-eight coal miners completed a questionnaire for known risk factors for low back pain, performed the Biering-Sorensen test, and undertook a test of aerobic fitness. Data analysis was performed to describe the groups and to determine whether any significant difference existed between those with a past history of low back pain and those without. Significantly lower than expected holding times were found in this group of coal miners (mean 113 s). This result was significantly lower than demonstrated in previous studies. When holding times for those with a past history of low back pain were compared with times for those with no history of low back pain, the difference was not statistically significant, nor was there a significant difference in fitness between those with a past history of low back pain and those without. It is concluded that coal miners in Australia have lower than normal Biering-Sorensen holding times. This lower back holding time does not differ between coal miners with a past history of low back pain and those without.

  14. Reliability and validity of a low load endurance strength test for upper and lower extremities in patients with fibromyalgia.

    Science.gov (United States)

    Munguía-Izquierdo, Diego; Legaz-Arrese, Alejandro

    2012-11-01

    To evaluate the reliability, standard error of the mean (SEM), clinical significant change, and known group validity of 2 assessments of endurance strength to low loads in patients with fibromyalgia syndrome (FS). Cross-sectional reliability and comparative study. University Pablo de Olavide, Seville, Spain. Middle-aged women with FS (n=95) and healthy women (n=64) matched for age, weight, and body mass index (BMI) were recruited for the study. Not applicable. The endurance strength to low loads tests of the upper and lower extremities and anthropometric measures (BMI) were used for the evaluations. The differences between the readings (tests 1 and 2) and the SDs of the differences, intraclass correlation coefficient (ICC) model (2,1), 95% confidence interval for the ICC, coefficient of repeatability, intrapatient SD, SEM, Wilcoxon signed-rank test, and Bland-Altman plots were used to examine reliability. A Mann-Whitney U test was used to analyze the differences in test values between the patient group and the control group. We hypothesized that patients with FS would have an endurance strength to low loads performance in lower and upper extremities at least twice as low as that of the healthy controls. Satisfactory test-retest reliability and SEMs were found for the lower extremity, dominant arm, and nondominant arm tests (ICC=.973-.979; P.05 for all). The Bland-Altman plots showed 95% limits of agreement for the lower extremity (4.7 to -4.5), dominant arm (3.8 to -4.4), and nondominant arm (3.9 to -4.1) tests. The endurance strength to low loads test scores for the patients with FS were 4-fold lower than for the controls in all performed tests (P<.001 for all). The endurance strength to low loads tests showed good reliability and known group validity and can be recommended for evaluating endurance strength to low loads in patients with FS. For individual evaluation, however, an improved score of at least 4 and 5 repetitions for the upper and lower extremities

  15. RESIDUAL RESOURCE STUDY OF DEFECTIVE RAILS FOR TYPE P 50 CYCLE TEST OF ENDURANCE

    Directory of Open Access Journals (Sweden)

    R. M. Yosyfovych

    2015-11-01

    Full Text Available Purpose. The paper is devoted to the study and evaluation of residual life for defective rails P50 operated on the roads of the Kyiv subway, which are taken out of service because of defects 11.1-2 on the side of the rolling surface of the rail head. Methodology. The studies were performed with the use of experimental methods: testing of samples of defective rails in the cyclical strength of the pulse machine and testing of defective rails in the static load limit on the hydraulic vertical press. Findings. The performed experiments indicate that on the tests basis in 2 million cycles is only a small development (increase in size 0.5-0.7 mm of existing code defects 11.2 as a result of shedding the particles of crumble out metal on the side of the rails head of working prototypes. The intensity and the catastrophic development of defects, such as 11.2, or transformation of these defects in defects such as 21.2 or 30G.2 did not happen in any case. Originality. For the first time in Ukraine with the theoretical calculations substantiated the greater possibility of defects formation of contact fatigue origin in the form of spall and jag of metal on the surface of the rail, at the edge of the head. It is the result of the creation of a high degree of stress nonequilibrium compression in this area, due to the high values of principal normal stresses and appearance of large shear stresses in the body of the head at a depth of 2.5-3.5 mm, exceeding the yield strength and metal endurance. The tests of experimental prototypes of defective rails on high cycle endurance (based № = 2,1h10 cycles with periodic defectoscopic control were conducted. Practical value. In experiments, the new data of the resistance ability to spall rail defects on the surface of the head of rolling on the code 11.1-2 long-term cyclic loading equal to operational magnitude at the wheel load test of 2 million cycles was obtained. That is, the defective rails can have residual life

  16. Validity of Alternative Fitnessgram Upper Body Tests of Muscular Strength and Endurance among Seventh and Eighth Grade Males and Females

    Science.gov (United States)

    Hobayan, Kalani; Patterson, Debra; Sherman, Clay; Wiersma, Lenny

    2014-01-01

    In a society in which obesity levels have tripled in the past 30 years, the importance of increased fitness levels within the academic setting has become even more critical. The purpose of this study was to investigate the validity of alternative Fitnessgram upper body tests of muscular strength and endurance among seventh and eighth grade males…

  17. Effects of endurance training and competition on exercise tests in relatively untrained people.

    Science.gov (United States)

    Verstappen, F T; Janssen, G M; Does, R J

    1989-10-01

    One hundred fourteen subjects (34 +/- 8 years) without any competition background took part in an endurance training study to be completed after 1.5 years with running a marathon. Ultimately, 60 males and 18 females achieved that goal. The training program, carefully supervised, was divided into three phases with a maximum of 45, 70, and 110 km/week training volume and concluded with a performance race of 15, 25, and 42.195 km, respectively. Three days before and 3 and 5 days after each race, 35 subjects were selected to perform a progressive treadmill test and the remaining subjects participated in performing field tests of running 400 and 1000 m. The maximal velocity achieved in the treadmill test was 4.75 +/- 0.36 m.s-1 for males and 4.18 +/- 0.28 m.s-1 for females; it remained constant throughout the study. However, the running velocity at 4 mmol.1(-1) plasma lactate concentration increased about 10% from phase 1 to 3. In the females this rise already appeared to be completed in phase 2. Heart rate showed a tendency to increase at both submaximal and maximal exercise from training phase 1 to 2 and 3, whereas plasma lactate concentration showed a decreasing tendency. Three days after the 25 km and the marathon race the maximal running velocity in the exercise test was 2%-4% lower compared with the pre-race test (P less than 0.05). Five days after the race this difference again faded away. This small decline in running performance was not reflected in changes of physiologic responses such as heart rate or plasma lactate concentration.

  18. Reliability and validity of lumbar and abdominal trunk muscle endurance tests in office workers with nonspecific subacute low back pain.

    Science.gov (United States)

    del Pozo-Cruz, Borja; Mocholi, Miguel H; del Pozo-Cruz, Jesus; Parraca, Jose A; Adsuar, Jose C; Gusi, Narcis

    2014-01-01

    Despite the widespread use of trunk endurance tests, the reliability and validity of these tests in office workers with subacute nonspecific low back pain are unknown. This cross-sectional study involved 190 subjects: 30 men and 42 women without low back pain and 47 men and 71 women with low back pain. All subjects underwent timed prone and supine isometric lumbar and abdominal trunk endurance tests that were performed until subjective fatigue occurred. All subjects also completed the Roland Morris and Oswestry self-reported disability questionnaires. A test-retest study (7 days) was conducted with 31 participants with low back pain from the study. For the abdominal trunk endurance test, males and females with low back pain had mean (SD) values of 62.06 (36.87) and 46.06 (29.28) seconds, respectively, both significantly lower than the asymptomatic workers. For the lumbar test, males and females with low back pain had mean (SD) values of 79.57 (30.66) and 75.49 (28.97) seconds, respectively, again, both significantly lower than the asymptomatic workers. The intraclass correlation coefficients of both tests exceeded 0.90 and the Kappa indices were excellent for both men and women. Receiver-operating curve analyses revealed areas under the curve very close to or exceeding 0.70 for both men and women for both tests. The lumbar and abdominal trunk muscle endurance tests appeared to be reliable and valid measures in office workers with subacute low back pain.

  19. CANFLEX fuel bundle cross-flow endurance test 2 (test procedure)

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Sung Deok; Chung, C. H.; Chang, S. K. [Korea Atomic Energy Research Institute, Taejon (Korea)

    1999-04-01

    This report describes test procedure of cross-flow 2 test for CANFLEX fuel. In October 1996. a cross-flow test was successfully performed in the KAERI Hot Test Loop for four hours at a water flow rate of 31kg/s, temperature of 266 deg C and inlet pressure of 11MPa, but it is requested more extended time periods to determine a realistic operational margin for the CANFLEX bundle during abnormal refuelling operations. The test shall be conducted for twenty two hours under the reactor conditions. After an initial period of ten hours, the test shall be stopped at the intervals of four hours for bundle inspection and inspect the test bundle end-plate to end-cap welds for failure or crack propagation using liquid penetrant examination. 2 refs., 1 fig. (Author)

  20. Is the timed loaded standing test a valid measure of back muscle endurance in people with vertebral osteoporosis?

    Science.gov (United States)

    Newman, M; Newman, R; Hughes, T; Vadher, K; Barker, K L

    2018-04-01

    Timed loaded standing (TLS) is a suggested measure of back muscle endurance for people with vertebral osteoporosis. Surface electromyography revealed back muscles work harder and fatigue during TLS. The test end-point and total time were associated with back fatigue. The findings help demonstrate the concurrent validity of the TLS test. The TLS test is suggested as a measure of back muscle endurance for patients with vertebral osteoporosis. However, to date, no study has demonstrated that TLS does measure back extensor or erector spinae (ES) muscle endurance. We used surface electromyography (sEMG) to investigate the performance of the thoracic ES muscles during TLS. Thirty-six people with vertebral osteoporosis with a mean age of 71.6 (range 45-86) years participated. sEMG recordings were made of the ES at T3 and T12 bilaterally during quiet standing (QS) and TLS. The relative (%) change in sEMG amplitude between conditions was compared. Fatigue was evaluated by analysing the change in median frequency (MF) of the sEMG signal during TLS, and the correlation between maximal TLS time and rate of MF decline was examined. Activity in the ES increased significantly during TLS at all electrode locations. During TLS, the MF declined at a mean rate of -24.2% per minute (95% C.I. -26.5 to -21.9%). The MF slope and test time were strongly correlated (r 2  = 0.71), and at test end, the final MF dropped to an average 89% (95% C.I. 85 to 93%) of initial MF. Twenty-eight participants (78%) reported fatigue was the main reason for stopping, and for eight (22%), it was pain. This study demonstrates that TLS challenges the ES muscles in the thoracic region and results in ES fatigue. Endurance time and the point at which the TLS test ends are strongly related to ES fatigue.

  1. Effects of endurance training on reduction of plasma glucose during high intensity constant and incremental speed tests in Wistar rats

    Directory of Open Access Journals (Sweden)

    P. Abreu

    Full Text Available The aim of this research was to investigate the effects of endurance training on reduction of plasma glucose during high intensity constant and incremental speed tests in Wistar rats. We hypothesized that plasma glucose might be decreased in the exercised group during heavy (more intense exercise. Twenty-four 10-week-old male Wistar rats were randomly assigned to sedentary and exercised groups. The prescription of endurance exercise training intensity was determined as 60% of the maximum intensity reached at the incremental speed test. The animals were trained by running on a motorized treadmill, five days/week for a total period of 67 weeks. Plasma glucose during the constant speed test in the exercised group at 20 m/min was reduced at the 14th, 21st and 28th min compared to the sedentary group, as well at 25 m/min at the 21st and 28th min. Plasma glucose during the incremental speed test was decreased in the exercised group at the moment of exhaustion (48th min compared to the sedentary group (27th min. Endurance training positively modulates the mitochondrial activity and capacity of substrate oxidation in muscle and liver. Thus, in contrast to other studies on high load of exercise, the effects of endurance training on the decrease of plasma glucose during constant and incremental speed tests was significantly higher in exercised than in sedentary rats and associated with improved muscle and hepatic oxidative capacity, constituting an important non-pharmacological intervention tool for the prevention of insulin resistance, including type 2 diabetes mellitus.

  2. Ball-Sport Endurance and Sprint Test (BEAST90): validity and reliability of a 90-minute soccer performance test.

    Science.gov (United States)

    Williams, Jeremy D; Abt, Grant; Kilding, Andrew E

    2010-12-01

    The aim of this study was to determine the validity and reliability of a 90-minute soccer performance test: Ball-sport Endurance and Sprint Test (BEAST90). Fifteen healthy male amateur soccer players participated and attended 5 testing sessions over a 10-day period to perform physiologic and soccer-specific assessments. This included familiarization sessions and 2 full trials of the BEAST90, separated by 7 days. The total 90-minute distance, mean percent peak heart rate (HRpeak), and estimated percent peak oxygen uptake of the BEAST90 were 8,097 ± 458 m, 85 ± 5% and 82 ± 14%, respectively. Measures obtained from trial 1 and trial 2 were not significantly different (p > 0.05). Reliability of measures over 90 minutes ranged from 0.9-25.5% (% typical error). The BEAST90 protocol replicated soccer match play in terms of time, movement patterns, physical demands (volume and intensity), distances, and mean and HRpeak values, as well as having an aerobic load similar to that observed during a soccer match. Reproducibility of key physical measures during the BEAST90 were mostly high, suggesting good reliability. The BEAST90 could be used in studies that wish to determine the effects of training or nutritional interventions on prolonged intermittent physical performance.

  3. The 6-min mastication test: a unique test to assess endurance of continuous chewing, normal values, reliability, reproducibility and usability in patients with mitochondrial disease

    NARCIS (Netherlands)

    Engel-Hoek, L. van den; Knuijt, S.; Gerven, M.H.J.C van; Lagarde, M.L.J.; Groothuis, J.T.; Groot, I.J.M. de; Janssen, M.C.

    2017-01-01

    In patients with mitochondrial disease, fatigue and muscle problems are the most common complaints. They also experience these complaints during mastication. To measure endurance of continuous mastication in patients with mitochondrial diseases, the 6-min mastication test (6MMT) was developed. This

  4. The application of the Yo-Yo intermittent endurance level 2 test to elite female soccer populations

    DEFF Research Database (Denmark)

    Bradley, P S; Bendiksen, M; Dellal, A

    2014-01-01

    The aim of this study was to evaluate the application of the Yo-Yo intermittent endurance test level 2 (Yo-Yo IE2) to elite female soccer populations. Elite senior (n = 92), youth (n = 42), domestic (n = 46) and sub-elite female soccer players (n = 19) carried out the Yo-Yo IE2 test on numerous...... occasions across the season. Test-retest coefficient of variation (CV) in Yo-Yo IE2 test performance in domestic female players was 4.5%. Elite senior female players' Yo-Yo IE2 test performances were better (P ... 1490 ± 447, 1261 ± 449, and 994 ± 373 m). For elite senior female players, wide midfielders (2057 ± 550 m) had a higher Yo-Yo IE2 test performance (P 

  5. Can persistence hunting signal male quality? A test considering digit ratio in endurance athletes.

    Directory of Open Access Journals (Sweden)

    Daniel Longman

    Full Text Available Various theories have been posed to explain the fitness payoffs of hunting success among hunter-gatherers. 'Having' theories refer to the acquisition of resources, and include the direct provisioning hypothesis. In contrast, 'getting' theories concern the signalling of male resourcefulness and other desirable traits, such as athleticism and intelligence, via hunting prowess. We investigated the association between androgenisation and endurance running ability as a potential signalling mechanism, whereby running prowess, vital for persistence hunting, might be used as a reliable signal of male reproductive fitness by females. Digit ratio (2D:4D was used as a proxy for prenatal androgenisation in 439 males and 103 females, while a half marathon race (21km, representing a distance/duration comparable with that of persistence hunting, was used to assess running ability. Digit ratio was significantly and positively correlated with half-marathon time in males (right hand: r = 0.45, p<0.001; left hand: r = 0.42, p<0.001 and females (right hand: r = 0.26, p<0.01; left hand: r = 0.23, p = 0.02. Sex-interaction analysis showed that this correlation was significantly stronger in males than females, suggesting that androgenisation may have experienced stronger selective pressure from endurance running in males. As digit ratio has previously been shown to predict reproductive success, our results are consistent with the hypothesis that endurance running ability may signal reproductive potential in males, through its association with prenatal androgen exposure. However, further work is required to establish whether and how females respond to this signalling for fitness.

  6. Ecological validity and reliability of an age-adapted endurance field test in young male soccer players

    DEFF Research Database (Denmark)

    Castagna, Carlo; Krustrup, Peter; D'Ottavio, Stefano

    2018-01-01

    The purpose of this study was to examine the reliability and the association with relevant match activities (ecological validity) of an age-adapted field test for intermittent high-intensity endurance known as Yo-Yo intermittent recovery level 1 children test (YYIR1C) in young male soccer players......-intensity metabolic power (r=0.46) distances. Match total distance was largely associated with YYIR1C (r=0.30). The results of this study showed that YYIR1C may be considered a valid and reliable field test for assessing intermittent high-intensity endurance in young male soccer players. Due to the relevance...... performance showed an excellent relative (ICC=0.94) and a good absolute reliability (TEM as %CV=5.1%). Very large and significant associations were found between YYIR1C performance and match high-intensity activity (r=0.53). Large correlations were found between YYIR1C and match sprinting (r=0.42) and high...

  7. Cardiorespiratory endurance evaluation using heart rate analysis during ski simulator exercise and the Harvard step test in elementary school students.

    Science.gov (United States)

    Lee, Hyo Taek; Roh, Hyo Lyun; Kim, Yoon Sang

    2016-01-01

    [Purpose] Efficient management using exercise programs with various benefits should be provided by educational institutions for children in their growth phase. We analyzed the heart rates of children during ski simulator exercise and the Harvard step test to evaluate the cardiopulmonary endurance by calculating their post-exercise recovery rate. [Subjects and Methods] The subjects (n = 77) were categorized into a normal weight and an overweight/obesity group by body mass index. They performed each exercise for 3 minutes. The cardiorespiratory endurance was calculated using the Physical Efficiency Index formula. [Results] The ski simulator and Harvard step test showed that there was a significant difference in the heart rates of the 2 body mass index-based groups at each minute. The normal weight and the ski-simulator group had higher Physical Efficiency Index levels. [Conclusion] This study showed that a simulator exercise can produce a cumulative load even when performed at low intensity, and can be effectively utilized as exercise equipment since it resulted in higher Physical Efficiency Index levels than the Harvard step test. If schools can increase sport durability by stimulating students' interests, the ski simulator exercise can be used in programs designed to improve and strengthen students' physical fitness.

  8. The influence of age, sex, bulb position, visual feedback, and the order of testing on maximum anterior and posterior tongue strength and endurance in healthy belgian adults.

    Science.gov (United States)

    Vanderwegen, Jan; Guns, Cindy; Van Nuffelen, Gwen; Elen, Rik; De Bodt, Marc

    2013-06-01

    This study collected data on the maximum anterior and posterior tongue strength and endurance in 420 healthy Belgians across the adult life span to explore the influence of age, sex, bulb position, visual feedback, and order of testing. Measures were obtained using the Iowa Oral Performance Instrument (IOPI). Older participants (more than 70 years old) demonstrated significantly lower strength than younger persons at the anterior and the posterior tongue. Endurance remains stable throughout the major part of life. Gender influence remains significant but minor throughout life, with males showing higher pressures and longer endurance. The anterior part of the tongue has both higher strength and longer endurance than the posterior part. Mean maximum tongue pressures in this European population seem to be lower than American values and are closer to Asian results. The normative data can be used for objective assessment of tongue weakness and subsequent therapy planning of dysphagic patients.

  9. Responsiveness of the Countermovement Jump and Handgrip Strength to an Incremental Running Test in Endurance Athletes: Influence of Sex.

    Science.gov (United States)

    García-Pinillos, Felipe; Delgado-Floody, Pedro; Martínez-Salazar, Cristian; Latorre-Román, Pedro Á

    2018-03-01

    The present study analyzed the acute effects of an incremental running test on countermovement jump (CMJ) and handgrip strength performance in endurance athletes, considering the effect of post-exercise recovery time and sex. Thirty-three recreationally trained long-distance runners, 20 men and 13 women, participated voluntarily in this study. The participants performed the Léger test, moreover, the CMJ and handgrip strength tests were carried out before and after the running test and during different stages of recovery (at the 1st min of recovery (posttest1), 5th min of recovery (posttest2), and 10th min of recovery (posttest3)). Two-way analysis of variance revealed a significant improvement in the CMJ (pre-posttest1, p = 0.001) and handgrip strength (pre-posttest2, p = 0.017) during recovery time. The Pearson's Chi-2 test showed no significant relationship ( p ≥ 0.05) between sex and post-activation potentiation (PAP). A linear regression analysis pointed to heart rate recovery as a predictive factor of CMJ improvement (PAP). In conclusion, despite significant fatigue reached during the Léger test, the long-distance runners did not experience an impaired CMJ and handgrip strength performance, either men or women, achieving an improvement (PAP) in posttest conditions. The results obtained showed no significant relationship between sex and PAP. Moreover, significant effect of recovery after running at high intensity on CMJ performance and handgrip strength was found. Finally, the data suggest that PAP condition can be predicted by heart rate recovery in endurance runners.

  10. Comparative endurance testing of the Biomet Matthews Nail and the Dynamic Compression Screw, in simulated condylar and supracondylar femoral fractures

    Directory of Open Access Journals (Sweden)

    Davies Benjamin M

    2008-01-01

    Full Text Available Abstract Background The dynamic compression screw is a plate and screws implant used to treat fractures of the distal femur. The Biomet Matthews Nail is a new retrograde intramedullary nail designed as an alternative surgical option to treat these fractures. The objective of this study was to assess the comparative endurance of both devices. Method The dynamic compression screw (DCS and Biomet Matthews Nail (BMN were implanted into composite femurs, which were subsequently cyclically loaded using a materials testing machine. Simulated fractures were applied to each femur prior to the application of load. Either a Y type fracture or a transverse osteotomy was prepared on each composite femur using a jig to enable consistent positioning of cuts. Results The Biomet Matthews Nail demonstrated a greater endurance limit load over the dynamic compression screw in both fracture configurations. Conclusion The distal locking screws pass through the Biomet Matthews Nail in a unique "cruciate" orientation. This allows for greater purchase in the bone of the femoral condyle and potentially improves the stability of the fracture fixation. As these fractures are usually in weak osteoporotic bone, the Biomet Matthews Nail represents a favourable surgical option in these patients.

  11. The application of the Yo-Yo intermittent endurance level 2 test to elite female soccer populations.

    Science.gov (United States)

    Bradley, P S; Bendiksen, M; Dellal, A; Mohr, M; Wilkie, A; Datson, N; Orntoft, C; Zebis, M; Gomez-Diaz, A; Bangsbo, J; Krustrup, P

    2014-02-01

    The aim of this study was to evaluate the application of the Yo-Yo intermittent endurance test level 2 (Yo-Yo IE2) to elite female soccer populations. Elite senior (n = 92), youth (n = 42), domestic (n = 46) and sub-elite female soccer players (n = 19) carried out the Yo-Yo IE2 test on numerous occasions across the season. Test-retest coefficient of variation (CV) in Yo-Yo IE2 test performance in domestic female players was 4.5%. Elite senior female players' Yo-Yo IE2 test performances were better (P wide midfielders (2057 ± 550 m) had a higher Yo-Yo IE2 test performance (P World Cup Finals (2049 ± 283 vs 1803 ± 342 m). The data demonstrate that the Yo-Yo IE2 test is reproducible and is an indicator of the match-specific physical capacity of female soccer players. Furthermore, the Yo-Yo IE2 test illustrates sensitivity by differentiating intermittent exercise performance of female players in various competitive levels, stages of the season and playing positions. © 2012 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Yo-Yo Intermittent Endurance Test-Level 1 to monitor changes in aerobic fitness in pre-pubertal boys

    DEFF Research Database (Denmark)

    Fernandes, Luís; Krustrup, Peter; Silva, Gustavo

    2016-01-01

    Abstract The present study aimed to examine the performance and heart rate responses during the Yo-Yo Intermittent Endurance Test-Level 1 (Yo-Yo IE1) in children under the age of 10. One hundred and seven male children (7-9 years) performed the Yo-Yo IE1 at the beginning (M1), middle (M2) and end...... (M3) of the school year. Data from individual heart rate curves of the Yo-Yo IE1 were analysed in order to detect the inflection point between an initial phase of fast rise in heart rate values and a second phase in which the rise of the heart rate values is much smaller. The distance covered...

  13. Uzobo, Endurance

    African Journals Online (AJOL)

    Uzobo, Endurance. Vol 11, No 1 (2016) - Articles Population and development in Nigeria: An assesment of the National Policy on Population and Sustainable Development Abstract PDF · Vol 12, No 1 (2017) - Articles Kin networks and migration in Sagbama Local Government Area of Bayelsa State Abstract PDF.

  14. Does core stability exercise improve lumbopelvic stability (through endurance tests) more than general exercise in chronic low back pain? A quasi-randomized controlled trial.

    Science.gov (United States)

    Shamsi, Mohammad Bagher; Rezaei, Mandana; Zamanlou, Mehdi; Sadeghi, Mehdi; Pourahmadi, Mohammad Reza

    2016-01-01

    The aim was to compare core stability and general exercises (GEs) in chronic low back pain (LBP) patients based on lumbopelvic stability (LPS) assessment through three endurance core stability tests. There is a controversy about preference of core stability exercise (CSE) over other types of exercise for chronic LBP. Studies which have compared these exercises used other outcomes than those related to LPS. As it is claimed that CSE enhances back stability, endurance tests for LPS were used. A 16-session CSE program and a GE program with the same duration were conducted for two groups of participants. Frequency of interventions for both groups was three times a week. Forty-three people (aged 18-60 years) with chronic non-specific LBP were alternately allocated to core stability (n = 22) or GE group (n = 21) when admitted. The primary outcomes were three endurance core stability tests including: (1) trunk flexor; (2) trunk extensor; and (3) side bridge tests. Secondary outcomes were disability and pain. Measurements were taken at baseline and the end of the intervention. After the intervention, test times increased and disability and pain decreased within groups. There was no significant difference between two groups in increasing test times (p = 0.23 to p = 0.36) or decreasing disability (p = 0.16) and pain (p = 0.73). CSE is not more effective than GE for improving endurance core stability tests and reducing disability and pain in chronic non-specific LBP patients.

  15. Testing the efficacy of existing force-endurance models to account for the prevalence of obesity in the workforce.

    Science.gov (United States)

    Pajoutan, Mojdeh; Cavuoto, Lora A; Mehta, Ranjana K

    2017-10-01

    This study evaluates whether the existing force-endurance relationship models are predictive of endurance time for overweight and obese individuals, and if not, provide revised models that can be applied for ergonomics practice. Data was collected from 141 participants (49 normal weight, 50 overweight, 42 obese) who each performed isometric endurance tasks of hand grip, shoulder flexion, and trunk extension at four levels of relative workload. Subject-specific fatigue rates and a general model of the force-endurance relationship were determined and compared to two fatigue models from the literature. There was a lack of fit between previous models and the current data for the grip (ICC = 0.8), with a shift toward lower endurance times for the new data. Application of the revised models can facilitate improved workplace design and job evaluation to accommodate the capacities of the current workforce.

  16. Reliability and validity of the test of incremental respiratory endurance measures of inspiratory muscle performance in COPD.

    Science.gov (United States)

    Formiga, Magno F; Roach, Kathryn E; Vital, Isabel; Urdaneta, Gisel; Balestrini, Kira; Calderon-Candelario, Rafael A; Campos, Michael A; Cahalin, Lawrence P

    2018-01-01

    The Test of Incremental Respiratory Endurance (TIRE) provides a comprehensive assessment of inspiratory muscle performance by measuring maximal inspiratory pressure (MIP) over time. The integration of MIP over inspiratory duration (ID) provides the sustained maximal inspiratory pressure (SMIP). Evidence on the reliability and validity of these measurements in COPD is not currently available. Therefore, we assessed the reliability, responsiveness and construct validity of the TIRE measures of inspiratory muscle performance in subjects with COPD. Test-retest reliability, known-groups and convergent validity assessments were implemented simultaneously in 81 male subjects with mild to very severe COPD. TIRE measures were obtained using the portable PrO2 device, following standard guidelines. All TIRE measures were found to be highly reliable, with SMIP demonstrating the strongest test-retest reliability with a nearly perfect intraclass correlation coefficient (ICC) of 0.99, while MIP and ID clustered closely together behind SMIP with ICC values of about 0.97. Our findings also demonstrated known-groups validity of all TIRE measures, with SMIP and ID yielding larger effect sizes when compared to MIP in distinguishing between subjects of different COPD status. Finally, our analyses confirmed convergent validity for both SMIP and ID, but not MIP. The TIRE measures of MIP, SMIP and ID have excellent test-retest reliability and demonstrated known-groups validity in subjects with COPD. SMIP and ID also demonstrated evidence of moderate convergent validity and appear to be more stable measures in this patient population than the traditional MIP.

  17. Reliability, sensitivity and validity of the assistant referee intermittent endurance test (ARIET) - a modified Yo-Yo IE2 test for elite soccer assistant referees

    DEFF Research Database (Denmark)

    Castagna, Carlo; Bendiksen, Mads; Impellizzeri, Franco M

    2012-01-01

    We examined the reliability and validity of the assistant referee intermittent endurance test (ARIET), a modified Yo-Yo IE2 test including shuttles of sideways running. The ARIET was carried out on 198 Italian (Serie A-B, Lega-Pro and National Level) and 47 Danish elite soccer assistant referees....... Reproducibility was tested for 41 assistant referees on four occasions each separated by one week. The ARIET intraclass correlation coefficients and typical error of measurement ranged from 0.96 to 0.99 and 3.1 to 5.7%, respectively. ARIET performance for Serie A and B was 23 and 25% greater than in Lega-Pro (P...... ARIET performance was significantly correlated with VO(2max) (r = 0.78, P ARIET (r = - 0.81, P

  18. Endurance of lead-free assembly under board level drop test and thermal cycling

    Energy Technology Data Exchange (ETDEWEB)

    Xia Yanghua [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China)], E-mail: xia_yanghua@hotmail.com; Xie Xiaoming [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China)

    2008-06-12

    The reliability of lead-free electronic assemblies under board level drop test and thermal cycling was investigated. TSOP (thin small outline package) devices with FeNi leads were reflow soldered on FR4 PCB (printed circuit board) with Sn3.0Ag0.5Cu (wt%) solder. The effects of different PCB finishes (organic solderability preservative (OSP) and electroless nickel immersion gold (ENIG)) on the reliability performance were studied. The results show that the assemblies with ENIG finishes reveal better reliability performance than its OSP counterparts under drop test, however, the OSP samples outperform those with ENIG finishes under thermal cycling. The failure mechanism is different under these two test conditions: the solder joints fracture into the intermetallic compounds (IMCs) layer under drop test, and cracks initiate in the bulk solder under thermal cycling. The surface finishes have an effect on the failure mode. The propagation of crack in the ENIG case is along the device/solder interface, while in the case of OSP, the crack extends parallel to the solder/PCB interface.

  19. The 6-min mastication test: a unique test to assess endurance of continuous chewing, normal values, reliability, reproducibility and usability in patients with mitochondrial disease.

    Science.gov (United States)

    van den Engel-Hoek, L; Knuijt, S; van Gerven, M H J C; Lagarde, M L J; Groothuis, J T; de Groot, I J M; Janssen, M C H

    2017-03-01

    In patients with mitochondrial disease, fatigue and muscle problems are the most common complaints. They also experience these complaints during mastication. To measure endurance of continuous mastication in patients with mitochondrial diseases, the 6-min mastication test (6MMT) was developed. This study included the collection of normal data for the 6MMT in a healthy population (children and adults). During 6 min of continuous mastication on a chew tube chewing cycles per minute, total amount of chewing cycles and the difference between minute 1 (M 1 ) and minute 6 (M 2 ) were collected in 271 healthy participants (5-80 years old). These results were compared with those of nine paediatric and 25 adult patients with a mitochondrial disease. Visual analogue scale (VAS) scores were collected directly after the test and after 5 min. A qualitative rating was made on masticatory movements. The reproducibility of the 6MMT in the healthy population with an interval of approximately 2 weeks was good. The inter-rater reliability for the observations was excellent. The patient group demonstrated lower total amount of chewing cycles or had greater differences between M 1 and M 6 . The 6MMT is a reliable and objective test to assess endurance of continuous chewing. It demonstrates the ability of healthy children and adults to chew during 6 min with a highly stable frequency of mastication movements. The test may give an explanation for the masticatory problems in patient groups, who are complaining of pain and fatigue during mastication. © 2017 John Wiley & Sons Ltd.

  20. Reliability and validity of the test of incremental respiratory endurance measures of inspiratory muscle performance in COPD

    Directory of Open Access Journals (Sweden)

    Formiga MF

    2018-05-01

    Full Text Available Magno F Formiga,1,2 Kathryn E Roach,1 Isabel Vital,3 Gisel Urdaneta,3 Kira Balestrini,3 Rafael A Calderon-Candelario,3,4 Michael A Campos,3,4,* Lawrence P Cahalin1,* 1Department of Physical Therapy, University of Miami Miller School of Medicine, Coral Gables, FL, USA; 2CAPES Foundation, Ministry of Education of Brazil, Brasilia, Brazil; 3Pulmonary Section, Miami Veterans Administration Medical Center, Miami, FL, USA; 4Division of Pulmonary, Allergy, Critical Care and Sleep Medicine, University of Miami Miller School of Medicine, Miami, FL, USA *These authors contributed equally to this work Purpose: The Test of Incremental Respiratory Endurance (TIRE provides a comprehensive assessment of inspiratory muscle performance by measuring maximal inspiratory pressure (MIP over time. The integration of MIP over inspiratory duration (ID provides the sustained maximal inspiratory pressure (SMIP. Evidence on the reliability and validity of these measurements in COPD is not currently available. Therefore, we assessed the reliability, responsiveness and construct validity of the TIRE measures of inspiratory muscle performance in subjects with COPD. Patients and methods: Test–retest reliability, known-groups and convergent validity assessments were implemented simultaneously in 81 male subjects with mild to very severe COPD. TIRE measures were obtained using the portable PrO2 device, following standard guidelines. Results: All TIRE measures were found to be highly reliable, with SMIP demonstrating the strongest test–retest reliability with a nearly perfect intraclass correlation coefficient (ICC of 0.99, while MIP and ID clustered closely together behind SMIP with ICC values of about 0.97. Our findings also demonstrated known-groups validity of all TIRE measures, with SMIP and ID yielding larger effect sizes when compared to MIP in distinguishing between subjects of different COPD status. Finally, our analyses confirmed convergent validity for both SMIP

  1. Endurance test of a 30-CM-diameter engineering model ion thruster. Task 12: Investigation of thin-film erosion monitors for ion thrusters

    Science.gov (United States)

    Beattie, J. R.

    1983-01-01

    An investigation of short term measurement techniques for predicting the wearout of ion thrusters resulting from sputter erosion damage is described. The previously established laminar thin film techniques to provide high precision erosion rate data. However, the erosion rates obtained using this technique are generally substantially higher than those obtained during long term endurance tests (by virtue of the as deposited nature of the thin films), so that the results must be interpreted in a relative sense. Absolute measurements can be performed using a new masked substrate arrangement which was developed during this study. This new technique provides a means for estimating the lifetimes of critical discharge chamber components based on direct measurements of sputter erosion depths obtained during short duration (10 hour) tests. The method enables the effects on lifetime of thruster design and operating parameters to be inferred without the investment of the time and capital required to conduct long term (1000 hour) endurance tests. Results obtained using the direct measurement technique are shown to agree with sputter erosion depths calculated for the plasma conditions of the test and also with lifetest results. The direct measurement approach is shown to be applicable to both mercury and argon discharge plasma environments and should be useful in estimating the lifetimes of inert gas and extended performance mercury ion thrusters presently under development.

  2. Content Validity Index and Intra- and Inter-Rater Reliability of a New Muscle Strength/Endurance Test Battery for Swedish Soldiers.

    Directory of Open Access Journals (Sweden)

    Helena Larsson

    Full Text Available The objective of this study was to examine the content validity of commonly used muscle performance tests in military personnel and to investigate the reliability of a proposed test battery. For the content validity investigation, thirty selected tests were those described in the literature and/or commonly used in the Nordic and North Atlantic Treaty Organization (NATO countries. Nine selected experts rated, on a four-point Likert scale, the relevance of these tests in relation to five different work tasks: lifting, carrying equipment on the body or in the hands, climbing, and digging. Thereafter, a content validity index (CVI was calculated for each work task. The result showed excellent CVI (≥0.78 for sixteen tests, which comprised of one or more of the military work tasks. Three of the tests; the functional lower-limb loading test (the Ranger test, dead-lift with kettlebells, and back extension, showed excellent content validity for four of the work tasks. For the development of a new muscle strength/endurance test battery, these three tests were further supplemented with two other tests, namely, the chins and side-bridge test. The inter-rater reliability was high (intraclass correlation coefficient, ICC2,1 0.99 for all five tests. The intra-rater reliability was good to high (ICC3,1 0.82-0.96 with an acceptable standard error of mean (SEM, except for the side-bridge test (SEM%>15. Thus, the final suggested test battery for a valid and reliable evaluation of soldiers' muscle performance comprised the following four tests; the Ranger test, dead-lift with kettlebells, chins, and back extension test. The criterion-related validity of the test battery should be further evaluated for soldiers exposed to varying physical workload.

  3. Sub-maximal and maximal Yo-Yo intermittent endurance test level 2: heart rate response, reproducibility and application to elite soccer

    DEFF Research Database (Denmark)

    Bradley, Paul S; Mohr, Magni; Bendiksen, Mads

    2011-01-01

    to detect test-retest changes and discriminate between performance for different playing standards and positions in elite soccer. Elite (n = 148) and sub-elite male (n = 14) soccer players carried out the Yo-Yo IE2 test on several occasions over consecutive seasons. Test-retest coefficient of variation (CV......) in Yo-Yo IE2 test performance and heart rate after 6 min were 3.9% (n = 37) and 1.4% (n = 32), respectively. Elite male senior and youth U19 players Yo-Yo IE2 performances were better (P ......The aims of this study were to (1) determine the reproducibility of sub-maximal and maximal versions of the Yo-Yo intermittent endurance test level 2 (Yo-Yo IE2 test), (2) assess the relationship between the Yo-Yo IE2 test and match performance and (3) quantify the sensitivity of the Yo-Yo IE2 test...

  4. Development of internal CRD for next generation BWR-endurance and robustness tests of ball-bearing materials in high-pressure and high-temperature water

    International Nuclear Information System (INIS)

    Shoji Goto; Shuichi Ohmori; Michitsugu Mori; Shohei Kawano; Tadashi Narabayashi; Shinichi Ishizato

    2005-01-01

    An internal CRD using a heatproof ceramics insulated coil is under development to be a competitive and higher performance as Next- Generation BWR. In the case of the 1700MWe next generation BWR, adapting the internal CRDs, the reactor pressure vessel is almost equivalent to that of 1356 MWe ABWR. The endurance and robustness tests were examined in order to confirm the durability of the bearing for the internal CRD. The durability of the ball bearing for the internal CRD was performed in the high-pressure and high-temperature reactor water of current BWR conditions. The experimental results confirmed the durability of rotational numbers for the operation length of 60 years. We added the cruds into water to confirm the robustness of the ball bearing. The test results also showed good robustness even in high-density crud conditions, compared with the current BWR. This program is conducted as one of the selected offers for the advertised technical developments of the Institute of Applied Energy founded by METI (Ministry of Economy, Trade and Industry) of Japan. (authors)

  5. Evaluation of Ratnaprash for its effect on strength, stamina and fatigue using swim endurance test and biochemical estimation in swiss albino mice.

    Science.gov (United States)

    Gupta, Arun; Kumar, Satyendra; Rajput, Rashmi; Srivastava, Ruchi; Rai, Rajiv K; Sastry, J L N

    2015-01-01

    Traditional medicines have been considered as important resources for postponing fatigue, accelerating elimination of fatigue related metabolites and improving physical ability. Rasāyanās or rejuvenative therapies are mentioned as one of the eight clinical specialties in Ayurveda for attaining longevity, healthy life and regulation of bodily balance. Eventhough more detailed studies are needed to confirm the claims of benefits in the light of evidence based research, Ratnaprash, a herbo-mineral rasāyana formulation, is proposed here to be an antifatigue supplement that is good in promoting strength and stamina. In the present study, anti fatigue, strength and stamina enhancing properties of Ratnaprash were examined based on swim endurance capacity and the change in biochemical parameters in Swiss Albino mice. Treatment groups were orally administered Ratnaprash at various test doses (500, 1000, 2000 mg/Kg per day), while the control group received distilled water at similar dose volumes. Effect of therapy was evaluated after 28 days of treatment. At the end of study period, the swimming times to exhaustion were longer in the treated groups than in the control group. Plasma lactate levels of treated groups were lower than those of the control group (P stamina and contributing anti-fatigue activity.

  6. Evaluation of Ratnaprash for its effect on strength, stamina and fatigue using swim endurance test and biochemical estimation in swiss albino mice

    Science.gov (United States)

    Gupta, Arun; Kumar, Satyendra; Rajput, Rashmi; Srivastava, Ruchi; Rai, Rajiv K.; Sastry, J. L. N.

    2015-01-01

    Context: Traditional medicines have been considered as important resources for postponing fatigue, accelerating elimination of fatigue related metabolites and improving physical ability. Rasāyanās or rejuvenative therapies are mentioned as one of the eight clinical specialties in Ayurveda for attaining longevity, healthy life and regulation of bodily balance. Eventhough more detailed studies are needed to confirm the claims of benefits in the light of evidence based research, Ratnaprash, a herbo-mineral rasāyana formulation, is proposed here to be an antifatigue supplement that is good in promoting strength and stamina. Materials and Methods: In the present study, anti fatigue, strength and stamina enhancing properties of Ratnaprash were examined based on swim endurance capacity and the change in biochemical parameters in Swiss Albino mice. Treatment groups were orally administered Ratnaprash at various test doses (500, 1000, 2000 mg/Kg per day), while the control group received distilled water at similar dose volumes. Effect of therapy was evaluated after 28 days of treatment. Results: At the end of study period, the swimming times to exhaustion were longer in the treated groups than in the control group. Plasma lactate levels of treated groups were lower than those of the control group (P increased tissue ATP levels in preclinical models in comparison to vehicle control, exhibiting possible role in increasing strength and stamina and contributing anti-fatigue activity. PMID:26600664

  7. Antioxidant and Antifatigue Properties of the Aqueous Extract of Moringa oleifera in Rats Subjected to Forced Swimming Endurance Test

    Science.gov (United States)

    Lamou, Bonoy; Taiwe, Germain Sotoing; Hamadou, André; Abene; Houlray, Justin; Atour, Mahamat Mey; Tan, Paul Vernyuy

    2016-01-01

    The effects of the aqueous extract of Moringa oleifera on swimming performance and related biochemical parameters were investigated in male Wistar rats (130–132 g). Four groups of rats (16 per group) were fed a standard laboratory diet and given distilled water, 100, 200, or 400 mg/kg of extract, respectively, for 28 days. On day 28, 8 rats from each group were subjected to the forced swimming test with tail load (10% of body weight). The remaining 8 rats per group were subjected to the 90-minute free swim. Maximum swimming time, glycemia, lactamia, uremia, triglyceridemia, hepatic and muscle glycogen, hematological parameters, and oxidative stress parameters (superoxide dismutase, catalase, reduced glutathione, and malondialdehyde) were measured. Results. M. oleifera extract increased maximum swimming time, blood hemoglobin, blood glucose, and hepatic and muscle glycogen reserves. The extract also increased the activity of antioxidant enzymes and decreased the blood concentrations of malondialdehyde. Furthermore, it decreased blood concentrations of lactate, triglycerides, and urea. In conclusion, the antifatigue properties of M. oleifera extract are demonstrated by its ability to improve body energy stores and tissue antioxidant capacity and to reduce the tissue build-up of lactic acid. PMID:26904162

  8. Antioxidant and Antifatigue Properties of the Aqueous Extract of Moringa oleifera in Rats Subjected to Forced Swimming Endurance Test.

    Science.gov (United States)

    Lamou, Bonoy; Taiwe, Germain Sotoing; Hamadou, André; Abene; Houlray, Justin; Atour, Mahamat Mey; Tan, Paul Vernyuy

    2016-01-01

    The effects of the aqueous extract of Moringa oleifera on swimming performance and related biochemical parameters were investigated in male Wistar rats (130-132 g). Four groups of rats (16 per group) were fed a standard laboratory diet and given distilled water, 100, 200, or 400 mg/kg of extract, respectively, for 28 days. On day 28, 8 rats from each group were subjected to the forced swimming test with tail load (10% of body weight). The remaining 8 rats per group were subjected to the 90-minute free swim. Maximum swimming time, glycemia, lactamia, uremia, triglyceridemia, hepatic and muscle glycogen, hematological parameters, and oxidative stress parameters (superoxide dismutase, catalase, reduced glutathione, and malondialdehyde) were measured. Results. M. oleifera extract increased maximum swimming time, blood hemoglobin, blood glucose, and hepatic and muscle glycogen reserves. The extract also increased the activity of antioxidant enzymes and decreased the blood concentrations of malondialdehyde. Furthermore, it decreased blood concentrations of lactate, triglycerides, and urea. In conclusion, the antifatigue properties of M. oleifera extract are demonstrated by its ability to improve body energy stores and tissue antioxidant capacity and to reduce the tissue build-up of lactic acid.

  9. An empirical test of the information-motivation-behavioral skills model of ART adherence in a sample of HIV-positive persons primarily in out-of-HIV-care settings.

    Science.gov (United States)

    Horvath, Keith J; Smolenski, Derek; Amico, K Rivet

    2014-02-01

    The current body of evidence supporting the Information-Motivation-Behavioral Skills (IMB) model of antiretroviral therapy (ART) adherence rests exclusively on data collected from people living with HIV (PLWH) at point-of-HIV-care services. The aims of this study were to: (1) determine if the IMB model is a useful predictive model of ART adherence among PLWH who were primarily recruited in out-of-HIV-care settings; and (2) assess whether the theorized associations between IMB model constructs and adherence persist in the presence of depression and current drug use. PLWH (n = 312) responding to a one-time online survey completed the Life Windows IMB-ART-Adherence Questionnaire, and demographic, depression (CES-D 10), and drug use items. Path models were used to assess the fit of a saturated versus fully mediated IMB model of adherence and examined for moderating effects of depression and current drug use. Participants were on average 43 years of age, had been living with HIV for 9 or more years, and mostly male (84.0%), Caucasian (68.8%), and gay-identified (74.8%). The a priori measurement models for information and behavioral skills did not have acceptable fit to the data and were modified accordingly. Using the revised IMB scales, IMB constructs were associated with adherence as predicted by the theory in all but one model (i.e., the IMB model operated as predicted among nondrug users and those with and without depression). Among drug users, information exerted a direct effect on adherence but was not significantly associated with behavioral skills. Results of this study suggest that the fully or partially mediated IMB model is supported for use with samples of PLWH recruited primarily out-of-HIV-care service settings and is robust in the presence of depression and drug use.

  10. EFFECTIVENESS OF LAND BASED ENDURANCE TRAINING VERSUS AQUATIC BASED ENDURANCE TRAINING ON IMPROVING ENDURANCE IN NORMAL INDIVIDUALS

    Directory of Open Access Journals (Sweden)

    Sabitha Eunice Regima

    2015-06-01

    Full Text Available Background: Recently the exercises and fitness professionals have adopted water as an alternative medium for delivering programs to improve fitness and health. When exercise on dry land our skeletal muscular, cardiovascular, respiratory and other body systems are greatly affected by the forces of gravity. When exercise in water, the effects created by the gravitational pull on the body are attenuated. Therefore the aim of this study was to determine the effectiveness of land based endurance training and aquatic based endurance training for enhancing endurance in normal individuals. Methods: An experimental study design with 30 subjects healthy individuals between 20-30 years of both sexes currently were divided equally into 2 groups. Group A underwent land based exercises while Group B underwent aquatic based exercises. The outcome measures consist of RPP (rate pressure product, REC HR (recovery heart rate, RHR (resting heart rate and 6MWD (6 minute walking distance was measured before (pre-training and after four weeks of endurance training. Results: In this study, the mean improvement between the 2 groups of land and aquatic based endurance exercises were tested for significance using a dependent t test. The calculated t value were 43.550, 4.583, 16, 5.870 for RPP, REC HR, RHR, 6MWD for group A respectively. For group B 25.922, 12.762, 27.495,19.236 for RPP, REC HR, RHR, 6MWD for group A respectively with p<0.05. This clearly indicated that both land based exercises and aquatic based exercises will improve cardiovascular endurance significantly and there is no significant difference between land based exercises and aquatic based exercises for enhancing endurance in normal individuals. Conclusion: It is concluded that both land based and aquatic based endurance exercises methods produce equivalent, if not same effect on the enhancement of aerobic endurance. There was no significant difference between these two exercising mediums. Nonetheless

  11. Effects of endurance training only versus same-session combined endurance and strength training on physical performance and serum hormone concentrations in recreational endurance runners.

    Science.gov (United States)

    Schumann, Moritz; Mykkänen, Olli-Pekka; Doma, Kenji; Mazzolari, Raffaele; Nyman, Kai; Häkkinen, Keijo

    2015-01-01

    This study investigated the effects of endurance training only (E, n = 14) and same-session combined training, when strength training is repeatedly preceded by endurance loading (endurance and strength training (E+S), n = 13) on endurance (1000-m running time during incremental field test) and strength performance (1-repetition maximum (1RM) in dynamic leg press), basal serum hormone concentrations, and endurance loading-induced force and hormone responses in recreationally endurance-trained men. E was identical in the 2 groups and consisted of steady-state and interval running, 4-6 times per week for 24 weeks. E+S performed additional mixed-maximal and explosive-strength training (2 times per week) immediately following an incremental running session (35-45 min, 65%-85% maximal heart rate). E and E+S decreased running time at week 12 (-8% ± 5%, p = 0.001 and -7% ± 3%, p force (-5% to -9%, p = 0.032 to 0.001) and testosterone and cortisol responses (18%-47%, p = 0.013 to p benefits when strength training was performed repeatedly after endurance training compared with endurance training only. This was supported by similar acute responses in force and hormonal measures immediately post-endurance loading after the training with sustained 1RM strength in E+S.

  12. Endurance Training - Science and Practice

    African Journals Online (AJOL)

    I have always had an interest in endurance sports and have been fortunate enough to work with endurance athletes while completing my PhD. Professor Mujika is a well-respected scientist who, apart from his research work, consults with many elite endurance athletes. I was surprised at how excited I was to review.

  13. ANTHROPOLOGY DIMENSIONS AS INDEPENDENT AEROBIC ENDURANCE

    Directory of Open Access Journals (Sweden)

    Ratko Pavlović

    2009-11-01

    Full Text Available Endurance as human capability is treated in two ways. Some authors define it as mobility capability, while others deny this theory. The denying of this theory lies in attitude that endurance is saturated with psychological factors (motivation and cardio- vascular factors as well and is often identified with aero power, typical dimension of fun- ctional diagnostics. Having that in mind this research enabled the obtaining of necessary informations which could contribute to the clearing up of these uncoordinated opinions. The research included 110 student of the III year Phisical Education in East Sarajevo, male gender. Nine (9 predictors has been applied (4 variables for mobility space estima- te, 5 variables for morphology and functional space estimate and variable used for the estimate of endurance race 1500m. Obtained results confirmed statistical significance of two functional capability variable of Harvard step test, Margarija test and mobility variable race 4x15 meters with the race results.

  14. Physiological responses of horses to a treadmill simulated speed and endurance test in high heat and humidity before and after humid heat acclimation.

    Science.gov (United States)

    Marlin, D J; Scott, C M; Schroter, R C; Harris, R C; Harris, P A; Roberts, C A; Mills, P C

    1999-01-01

    To investigate whether horses were able to acclimate to conditions of high temperature and humidity, 5 horses of different breeds were trained for 80 min on 15 consecutive days on a treadmill at 30 degrees C and 80%RH. Training consisted of a combination of long duration low-intensity exercise, medium duration medium intensity exercise and short duration high intensity exercise. Between training sessions the horses were maintained at 11+/-3 degrees C and 74+/-2%RH. Before (PRE-ACC) and after acclimation (POST-ACC) the horses undertook a simulated Competition Exercise Test (CET), designed to represent the Speed and Endurance Test of a 3-day event, at 30 degrees C/80%RH. Maximal oxygen uptake (VO2PEAK) was not changed following acclimation (PRE-ACC 141+/-8 ml/min/kg bwt vs. POST-ACC 145+/-9 ml/min/kg bwt [STPD], P>0.05). Following acclimation, 4 of the 5 horses were able to complete a significantly greater amount of Phase D in the CET (PRE-ACC 6.3+/-0.3 min vs. POST-ACC 7.3+/-0.3 min, P<0.05; target time = 8 min). Resting body temperatures (pulmonary artery [TPA], rectal [TREC] and tail-skin [TTSK] temperatures) were all significantly lower following acclimation. During exercise, metabolic heat production (M) and heat dissipation (HD), for the same exercise duration, were both significantly lower following acclimation (P<0.05), although heat storage (HS) was significantly higher (P<0.05). The higher heat storage following acclimation was associated with a lower TTSK for a given TPA and a decreased total fluid loss (% bodyweight, P<0.05). Plasma volume was not changed following acclimation. The relationship of sweating rate (SR) to TPA or TTSK on either the neck or the gluteal region was not significantly altered by acclimation, although the onset of sweating occurred at a lower TPA or TTSK following acclimation (P<0.05). The horses in the present study showed a number of physiological adaptations to a period of 15 days of exposure to high heat and humidity consistent

  15. Reassessing the structure of enduring leisure involvement

    Science.gov (United States)

    Jinhee Jun; Gerard T. Kyle; Symeon P. Vlachopoulos; Nicholas D. Theodorakis; James D. Absher; William E. Hammitt

    2012-01-01

    Using data collected from U.S. and Greek respondents, we tested an alternate conceptualization of enduring leisure involvement where identity was considered a key driver of other affective and conative outcomes. Rather than existing on the same temporal plane, as has been the tradition in the leisure literature, we observed that identity was an antecedent of the other...

  16. Endurance training at altitude.

    Science.gov (United States)

    Saunders, Philo U; Pyne, David B; Gore, Christopher J

    2009-01-01

    Since the 1968 Olympic Games when the effects of altitude on endurance performance became evident, moderate altitude training ( approximately 2000 to 3000 m) has become popular to improve competition performance both at altitude and sea level. When endurance athletes are exposed acutely to moderate altitude, a number of physiological responses occur that can comprise performance at altitude; these include increased ventilation, increased heart rate, decreased stroke volume, reduced plasma volume, and lower maximal aerobic power ((.)Vo(2max)) by approximately 15% to 20%. Over a period of several weeks, one primary acclimatization response is an increase in the volume of red blood cells and consequently of (.)Vo(2max). Altitudes > approximately 2000 m for >3 weeks and adequate iron stores are required to elicit these responses. However, the primacy of more red blood cells for superior sea-level performance is not clear-cut since the best endurance athletes in the world, from Ethiopia (approximately 2000 to 3000 m), have only marginally elevated hemoglobin concentrations. The substantial reduction in (.)Vo(2max) of athletes at moderate altitude implies that their training should include adequate short-duration (approximately 1 to 2 min), high-intensity efforts with long recoveries to avoid a reduction in race-specific fitness. At the elite level, athlete performance is not dependent solely on (.)Vo(2max), and the "smallest worthwhile change" in performance for improving race results is as little as 0.5%. Consequently, contemporary statistical approaches that utilize the concept of the smallest worthwhile change are likely to be more appropriate than conventional statistical methods when attempting to understand the potential benefits and mechanisms of altitude training.

  17. Mental toughness latent profiles in endurance athletes.

    Science.gov (United States)

    Zeiger, Joanna S; Zeiger, Robert S

    2018-01-01

    Mental toughness in endurance athletes, while an important factor for success, has been scarcely studied. An online survey was used to examine eight mental toughness factors in endurance athletes. The study aim was to determine mental toughness profiles via latent profile analysis in endurance athletes and whether associations exist between the latent profiles and demographics and sports characteristics. Endurance athletes >18 years of age were recruited via social media outlets (n = 1245, 53% female). Mental toughness was measured using the Sports Mental Toughness Questionnaire (SMTQ), Psychological Performance Inventory-Alternative (PPI-A), and self-esteem was measured using the Rosenberg Self-Esteem Scale (RSE). A three-class solution emerged, designated as high mental toughness (High MT), moderate mental toughness (Moderate MT) and low mental toughness (Low MT). ANOVA tests showed significant differences between all three classes on all 8 factors derived from the SMTQ, PPI-A and the RSE. There was an increased odds of being in the High MT class compared to the Low MT class for males (OR = 1.99; 95% CI, 1.39, 2.83; Pathletes who were over 55 compared to those who were 18-34 (OR = 2.52; 95% CI, 1.37, 4.62; Pathletes. High MT is associated with demographics and sports characteristics. Mental toughness screening in athletes may help direct practitioners with mental skills training.

  18. Is Self-Sacrificial Competitive Altruism Primarily a Male Activity?

    Directory of Open Access Journals (Sweden)

    Francis T. McAndrew

    2012-01-01

    Full Text Available This study explored the basis of self-sacrificial prosocial behavior in small groups. Seventy-eight undergraduates (39M, 39F filled out a thirty-item personality scale and then participated in a “group problem-solving study” in which the monetary success of a three-person group depended upon one of its members volunteering to endure pain (a cold stressor test and inconvenience (being soaked in a dunk tank. There were 13 groups consisting of two females and one male, and 13 groups consisting of two males and one female. Across groups, the behavior of the altruist was judged to be more costly, challenging, and important and he/she was liked better, rewarded with more money, and preferred as a future experimental partner. Groups containing two males showed more evidence of competition to become altruists than groups containing two females, and personality traits were more effective predictors of altruistic behavior in males than in females. We conclude that competition between males and “showing off” are key factors in triggering self-sacrificial altruistic behavior.

  19. Mental toughness latent profiles in endurance athletes.

    Directory of Open Access Journals (Sweden)

    Joanna S Zeiger

    Full Text Available Mental toughness in endurance athletes, while an important factor for success, has been scarcely studied. An online survey was used to examine eight mental toughness factors in endurance athletes. The study aim was to determine mental toughness profiles via latent profile analysis in endurance athletes and whether associations exist between the latent profiles and demographics and sports characteristics. Endurance athletes >18 years of age were recruited via social media outlets (n = 1245, 53% female. Mental toughness was measured using the Sports Mental Toughness Questionnaire (SMTQ, Psychological Performance Inventory-Alternative (PPI-A, and self-esteem was measured using the Rosenberg Self-Esteem Scale (RSE. A three-class solution emerged, designated as high mental toughness (High MT, moderate mental toughness (Moderate MT and low mental toughness (Low MT. ANOVA tests showed significant differences between all three classes on all 8 factors derived from the SMTQ, PPI-A and the RSE. There was an increased odds of being in the High MT class compared to the Low MT class for males (OR = 1.99; 95% CI, 1.39, 2.83; P<0.001, athletes who were over 55 compared to those who were 18-34 (OR = 2.52; 95% CI, 1.37, 4.62; P<0.01, high sports satisfaction (OR = 8.17; 95% CI, 5.63, 11.87; P<0.001, and high division placement (OR = 2.18; 95% CI, 1.46,3.26; P<0.001. The data showed that mental toughness latent profiles exist in endurance athletes. High MT is associated with demographics and sports characteristics. Mental toughness screening in athletes may help direct practitioners with mental skills training.

  20. Physical fitness differences of students with different cardiorespiratory endurance levels

    Directory of Open Access Journals (Sweden)

    Stojanović Darko

    2016-01-01

    Full Text Available In order to determine physical fitness differences in students with different cardiorespiratory endurance levels, a study was conducted on a sample of students of the Faculty of Sport and Physical Education at the University of Nis. The sample was divided into two subsamples, where the first subsample comprised 27 female students and the other 35 male students. Physical fitness was assessed using eight tests from the Eurofit battery of tests: the single-leg balance test - for the assessment of general balance, plate tapping - for the assessment of speed of movement, sit-and-reach - for the assessment of flexibility, the standing broad jump - for the assessment of explosive strength, the handgrip test - for the assessment of static strength, sit-ups - for the assessment of repetitive trunk strength, the bent arm hang - for the assessment of muscular endurance and the 10x5 meter shuttle run - for the assessment of the speed/agility. Cardiorespiratory endurance was estimated with the aid of 20 m endurance shuttle-run test. Based on the level of cardiorespiratory endurance, the participants in each subsample, were divided into three groups using a cluster analysis: high (VKRI, average (PKRI and low level (NKRI. The physical fitness differences of students with different cardiorespiratory endurance levels were calculated using the one-way analysis of variance. The results showed that there were no differences in physical fitness of students with different cardiorespiratory endurance levels. Based on the results it can be concluded that the level of cardiorespiratory endurance does not affect the components of physical fitness among students of both sexes.

  1. Wytrzymałość pływacka i biegowa studentów kierunku wychowanie fizyczne na podstawie testu Coopera = Endurance swimming and gear students of physical education based on the basis of the Cooper's test

    OpenAIRE

    Jan Banach; Mirosława Cieślicka; Radosław Muszkieta; Walery Zukow; Robert Stępniak

    2015-01-01

    Banach Jan, Cieślicka Mirosława, Muszkieta Radosław, Zukow Walery, Stępniak Robert. Wytrzymałość pływacka i biegowa studentów kierunku wychowanie fizyczne na podstawie testu Coopera = Endurance swimming and gear students of physical education based on the basis of the Cooper's test. Journal of Education, Health and Sport. 2015;5(5):445-462. ISSN 2391-8306. DOI 10.5281/zenodo.18157 http://ojs.ukw.edu.pl/index.php/johs/article/view/2015%3B5%285%29%3A445-462 https://pbn.nauka.gov.pl/work...

  2. Wytrzymałość pływacka i biegowa studentów kierunku wychowanie fizyczne na podstawie testu Coopera = Endurance swimming and gear students of physical education based on the basis of the Cooper's test

    OpenAIRE

    Banach, Jan; Cieślicka, Mirosława; Muszkieta, Radosław; Zukow, Walery; Stępniak, Robert

    2015-01-01

    Banach Jan, Cieślicka Mirosława, Muszkieta Radosław, Zukow Walery, Stępniak Robert. Wytrzymałość pływacka i biegowa studentów kierunku wychowanie fizyczne na podstawie testu Coopera = Endurance swimming and gear students of physical education based on the basis of the Cooper's test. Journal of Education, Health and Sport. 2015;5(5):445-462. ISSN 2391-8306. DOI 10.5281/zenodo.18157 http://ojs.ukw.edu.pl/index.php/johs/article/view/2015%3B5%285%29%3A445-462 https://pbn.nauka.gov.pl/work...

  3. Altitude and endurance training.

    Science.gov (United States)

    Rusko, Heikki K; Tikkanen, Heikki O; Peltonen, Juha E

    2004-10-01

    The benefits of living and training at altitude (HiHi) for an improved altitude performance of athletes are clear, but controlled studies for an improved sea-level performance are controversial. The reasons for not having a positive effect of HiHi include: (1) the acclimatization effect may have been insufficient for elite athletes to stimulate an increase in red cell mass/haemoglobin mass because of too low an altitude (altitude training period (training effect at altitude may have been compromised due to insufficient training stimuli for enhancing the function of the neuromuscular and cardiovascular systems; and (3) enhanced stress with possible overtraining symptoms and an increased frequency of infections. Moreover, the effects of hypoxia in the brain may influence both training intensity and physiological responses during training at altitude. Thus, interrupting hypoxic exposure by training in normoxia may be a key factor in avoiding or minimizing the noxious effects that are known to occur in chronic hypoxia. When comparing HiHi and HiLo (living high and training low), it is obvious that both can induce a positive acclimatization effect and increase the oxygen transport capacity of blood, at least in 'responders', if certain prerequisites are met. The minimum dose to attain a haematological acclimatization effect is > 12 h a day for at least 3 weeks at an altitude or simulated altitude of 2100-2500 m. Exposure to hypoxia appears to have some positive transfer effects on subsequent training in normoxia during and after HiLo. The increased oxygen transport capacity of blood allows training at higher intensity during and after HiLo in subsequent normoxia, thereby increasing the potential to improve some neuromuscular and cardiovascular determinants of endurance performance. The effects of hypoxic training and intermittent short-term severe hypoxia at rest are not yet clear and they require further study.

  4. Wytrzymałość pływacka i biegowa studentów kierunku wychowanie fizyczne na podstawie testu Coopera = Endurance swimming and gear students of physical education based on the basis of the Cooper's test

    Directory of Open Access Journals (Sweden)

    Jan Banach

    2015-05-01

    IKF, WKFZIT, Uniwersytet Kazimierza Wielkiego w Bydgoszczy                           Streszczenie          Wytrzymałość i wydolność można badać różnymi metodami. Na kierunku wychowania fizycznego Uniwersytety Kazimierza Wielkiego podjęto badania metodą  biegowego i pływackiego testu Coopera. Do badań na sali gimnastycznej i na pływalni przystąpiło i ukończyło 59 studentów. Dokonano analizy wyników z podziałem na wyniki kobiet i mężczyzn z wyróżnieniem studentów uprawiających czynnie wybrane dyscypliny sportu. Wynikiem pracy jest stwierdzenie że przebadani  studenci posiadają w znakomitej większość bardzo dobrą i dobrą wytrzymałość. Nie stwierdzono aby studenci czynnie uprawiający wybrane dyscypliny sportowe wyróżniali się wyższą wytrzymałością.   Słowa kluczowe: pływanie, Test pływacki, Test Coopera, wytrzymałość.   Abstract Endurance performance can be investigated by different methods. At the direction of physical education Universities Casimir the Great been investigated by cross-country skiing and swimming Cooper test. To study the gym and the swimming pool has acceded and graduated 59 students. The analysis of the results from the division of the results for men and women with honors students engaged actively chosen sport. The result of work is the finding that students have screened the vast majority of very good and good strength. There were no students to actively cultivating selected sports disciplines distinguished by a higher resistance.   Keywords: swimming, pool Test, Test Cooper endurance.

  5. Protein Requirements Are Elevated in Endurance Athletes after Exercise as Determined by the Indicator Amino Acid Oxidation Method.

    Directory of Open Access Journals (Sweden)

    Hiroyuki Kato

    Full Text Available A higher protein intake has been recommended for endurance athletes compared with healthy non-exercising individuals based primarily on nitrogen balance methodology. The aim of this study was to determine the estimated average protein requirement and recommended protein intake in endurance athletes during an acute 3-d controlled training period using the indicator amino acid oxidation method. After 2-d of controlled diet (1.4 g protein/kg/d and training (10 and 5km/d, respectively, six male endurance-trained adults (28±4 y of age; Body weight, 64.5±10.0 kg; VO2peak, 60.3±6.7 ml·kg-1·min-1; means±SD performed an acute bout of endurance exercise (20 km treadmill run prior to consuming test diets providing variable amounts of protein (0.2-2.8 g·kg-1·d-1 and sufficient energy. Protein was provided as a crystalline amino acid mixture based on the composition of egg protein with [1-13C]phenylalanine provided to determine whole body phenylalanine flux, 13CO2 excretion, and phenylalanine oxidation. The estimated average protein requirement was determined as the breakpoint after biphasic linear regression analysis with a recommended protein intake defined as the upper 95% confidence interval. Phenylalanine flux (68.8±8.5 μmol·kg-1·h-1 was not affected by protein intake. 13CO2 excretion displayed a robust bi-phase linear relationship (R2 = 0.86 that resulted in an estimated average requirement and a recommended protein intake of 1.65 and 1.83 g protein·kg-1·d-1, respectively, which was similar to values based on phenylalanine oxidation (1.53 and 1.70 g·kg-1·d-1, respectively. We report a recommended protein intake that is greater than the RDA (0.8 g·kg-1·d-1 and current recommendations for endurance athletes (1.2-1.4 g·kg-1·d-1. Our results suggest that the metabolic demand for protein in endurance-trained adults on a higher volume training day is greater than their sedentary peers and current recommendations for athletes based

  6. Human punishment is not primarily motivated by inequality.

    Science.gov (United States)

    Marczyk, Jesse

    2017-01-01

    Previous theorizing about punishment has suggested that humans desire to punish inequality per se. However, the research supporting such an interpretation contains important methodological confounds. The main objective of the current experiment was to remove those confounds in order to test whether generating inequality per se is punished. Participants were recruited from an online market to take part in a wealth-alteration game with an ostensible second player. The participants were given an option to deduct from the other player's payment as punishment for their behavior during the game. The results suggest that human punishment does not appear to be motivated by inequality per se, as inequality that was generated without inflicting costs on others was not reliably punished. Instead, punishment seems to respond primarily to the infliction of costs, with inequality only becoming relevant as a secondary input for punishment decisions. The theoretical significance of this finding is discussed in the context of its possible adaptive value.

  7. Human punishment is not primarily motivated by inequality

    Science.gov (United States)

    Marczyk, Jesse

    2017-01-01

    Previous theorizing about punishment has suggested that humans desire to punish inequality per se. However, the research supporting such an interpretation contains important methodological confounds. The main objective of the current experiment was to remove those confounds in order to test whether generating inequality per se is punished. Participants were recruited from an online market to take part in a wealth-alteration game with an ostensible second player. The participants were given an option to deduct from the other player’s payment as punishment for their behavior during the game. The results suggest that human punishment does not appear to be motivated by inequality per se, as inequality that was generated without inflicting costs on others was not reliably punished. Instead, punishment seems to respond primarily to the infliction of costs, with inequality only becoming relevant as a secondary input for punishment decisions. The theoretical significance of this finding is discussed in the context of its possible adaptive value. PMID:28187166

  8. Human punishment is not primarily motivated by inequality.

    Directory of Open Access Journals (Sweden)

    Jesse Marczyk

    Full Text Available Previous theorizing about punishment has suggested that humans desire to punish inequality per se. However, the research supporting such an interpretation contains important methodological confounds. The main objective of the current experiment was to remove those confounds in order to test whether generating inequality per se is punished. Participants were recruited from an online market to take part in a wealth-alteration game with an ostensible second player. The participants were given an option to deduct from the other player's payment as punishment for their behavior during the game. The results suggest that human punishment does not appear to be motivated by inequality per se, as inequality that was generated without inflicting costs on others was not reliably punished. Instead, punishment seems to respond primarily to the infliction of costs, with inequality only becoming relevant as a secondary input for punishment decisions. The theoretical significance of this finding is discussed in the context of its possible adaptive value.

  9. Investigation of Cardiovascular Endurance Levels of Sedentary High School Students

    Science.gov (United States)

    Akyol, Betül; Sögüt, Kayhan

    2018-01-01

    The aim of our study is to examine the cardiovascular endurance systems of sedentary high school students. The 112 sedentary individual was taken to the 1600 meter walking test run, and the 120 sedentary individual Harward step test. While both individuals were participating in the same test, weight, height, oxygen saturation, and heart rate of…

  10. Nutritional Supplements for Endurance Athletes

    Science.gov (United States)

    Rasmussen, Christopher J.

    Athletes engaged in heavy endurance training often seek additional nutritional strategies to help maximize performance. Specific nutritional supplements exist to combat certain factors that limit performance beginning with a sound everyday diet. Research has further demonstrated that safe, effective, legal supplements are in fact available for today's endurance athletes. Several of these supplements are marketed not only to aid performance but also to combat the immunosuppressive effects of intense endurance training. It is imperative for each athlete to research the legality of certain supplements for their specific sport or event. Once the legality has been established, it is often up to each individual athlete to decipher the ethics involved with ingesting nutritional supplements with the sole intent of improving performance.

  11. Comparison between two types of anaerobic speed endurance training in competitive soccer players

    DEFF Research Database (Denmark)

    Mohr, Magni; Krustrup, Peter

    2016-01-01

    The purpose of the present study was to examine the effects of additional in-season speed endurance production versus speed endurance maintenance training regimes on performance in competitive male soccer players. In a randomised controlled trial 18 male sub-elite players were exposed to additional...... during training were higher (psoccer players with superior...... speed endurance production (SEP) or speed endurance maintenance (SEM) training (two additional sessions/wk for 4 weeks) during the competitive season. Players performed the Yo-Yo intermittent recovery level 2 test (YYIR2) and a repeated sprint test (RST) pre- and postintervention. Yo-Yo IR2 performance...

  12. Effects of Endurance and Endurance Strength Training on Body Composition and Physical Capacity in Women with Abdominal Obesity

    Science.gov (United States)

    Skrypnik, Damian; Bogdański, Paweł; Mądry, Edyta; Karolkiewicz, Joanna; Ratajczak, Marzena; Kryściak, Jakub; Pupek-Musialik, Danuta; Walkowiak, Jarosław

    2015-01-01

    Aims To compare the effects of endurance training with endurance strength training on the anthropometric, body composition, physical capacity, and circulatory parameters in obese women. Methods 44 women with abdominal obesity were randomized into groups A and B, and asked to perform endurance (A) and endurance strength training (B) for 3 months, 3 times/week, for 60 min. Dual-energy X-ray absorptiometry and Graded Exercise Test were performed before and after training. Results Significant decreases in body mass, BMI, total body fat, total body fat mass, and waist and hip circumference were observed after both types of intervention. Marked increases in total body lean and total body fat-free mass were documented in group B. In both groups, significant increases in peak oxygen uptake, time to exhaustion, maximal work rate, and work rate at ventilatory threshold were accompanied by noticeably decreased resting heart rate, resting systolic blood pressure, and resting and exercise diastolic blood pressure. No significant differences were noticed between groups for the investigated parameters. Conclusion Our findings demonstrate evidence for a favorable and comparable effect of 3-month endurance and endurance strength training on anthropometric parameters, body composition, physical capacity, and circulatory system function in women with abdominal obesity. PMID:25968470

  13. Endurance running performance in athletes with asthma.

    Science.gov (United States)

    Freeman, W; Williams, C; Nute, M G

    1990-01-01

    Laboratory assessment was made during maximal and submaximal exercise on 16 endurance trained male runners with asthma (aged 35 +/- 9 years) (mean +/- S.D.). Eleven of these asthmatic athletes had recent performance times over a half-marathon, which were examined in light of the results from the laboratory tests. The maximum oxygen uptake (VO2max) of the group was 61.8 +/- 6.3 ml kg-1 min-1 and the maximum ventilation (VEmax) was 138.7 +/- 24.7 l min-1. These maximum cardio-respiratory responses to exercise were positively correlated to the degree of airflow obstruction, defined as the forced expiratory volume in 1 s (expressed as a percentage of predicted normal). The half-marathon performance times of 11 of the athletes ranged from those of recreational to elite runners (82.4 +/- 8.8 min, range 69-94). Race pace was correlated with VO2max (r = 0.863, P less than 0.01) but the highest correlation was with the running velocity at a blood lactate concentration of 2 mmol l-1 (r = 0.971, P less than 0.01). The asthmatic athletes utilized 82 +/- 4% VO2max during the half-marathon, which was correlated with the %VO2max at 2 mmol l-1 blood lactate (r = 0.817, P less than 0.01). The results of this study suggest that athletes with mild to moderate asthma can possess high VO2max values and can develop a high degree of endurance fitness, as defined by their ability to sustain a high percentage of VO2max over an endurance race. In athletes with more severe airflow obstruction, the maximum ventilation rate may be reduced and so VO2max may be impaired. The athletes in the present study have adapted to this limitation by being able to sustain a higher %VO2max before the accumulation of blood lactate, which is an advantage during an endurance race. Therefore, with appropriate training and medication, asthmatics can successfully participate in endurance running at a competitive level.

  14. Functional connectivity between core and shoulder muscles increases during isometric endurance contractions in judo competitors

    DEFF Research Database (Denmark)

    Kawczyński, Adam; Samani, Afshin; Mroczek, Dariusz

    2015-01-01

    endurance contraction consisting of bilateral arm abduction at 90°. The normalized mutual information (NMI) was computed between muscle pairs as an index indicating functional connectivity. Results: The NMIs increased significantly during endurance test for 10 of the 15 muscle pairs (P ... : We concluded that the increases in NMIs highlighted functional changes in the interplay between core and shoulder muscles during an endurance contraction in elite judokas....

  15. 'Endurance' Courtesy of Mars Express

    Science.gov (United States)

    2004-01-01

    NASA's Mars Exploration Rover Opportunity used its panoramic camera to capture this false-color image of the interior of 'Endurance Crater' on the rover's 188th martian day (Aug. 4, 2004). The image data were relayed to Earth by the European Space Agency's Mars Express orbiter. The image was generated from separate frames using the cameras 750-, 530- and 480-nanometer filters.

  16. Soccer Endurance Development in Professionals

    NARCIS (Netherlands)

    Roescher, C. R.; Elferink-Gemser, M. T.; Huijgen, B. C. H.; Visscher, C.

    The development of intermittent endurance capacity, its underlying mechanisms and role in reaching professional level in soccer was investigated. The sample included 130 talented youth soccer players aged 14-18, who became professional (n = 53) or non-professional (n = 77) players in adulthood. In

  17. Hypertension in master endurance athletes.

    Science.gov (United States)

    Hernelahti, M; Kujala, U M; Kaprio, J; Karjalainen, J; Sarna, S

    1998-11-01

    To determine whether long-term very vigorous endurance training prevents hypertension. Cohort study of master orienteering runners and controls. Finland. In 1995, a health questionnaire was completed by 264 male orienteering runners (response rate 90.4%) who had been top-ranked in competitions among men aged 35-59 years in 1984, and by 388 similarly aged male controls (response rate 87.1%) who were healthy at the age of 20 years and free of overt ischemic heart disease in 1985. Self-report of medication for hypertension. In the endurance athlete group, the crude prevalence (8.7%) of subjects who had used medication for hypertension was less than a third of that in the control group (27.8%). Even after adjusting for age and body mass index, the difference between the groups was still significant (odds ratio for athletes 0.43, 95% confidence interval 0.25-0.76). Long-term vigorous endurance training is associated with a low prevalence of hypertension. Some of the effect can be explained by a lower body mass, but exercise seems to induce a lower rate of hypertension by other mechanisms than by decreasing body weight

  18. Pedalling rate affects endurance performance during high-intensity cycling

    DEFF Research Database (Denmark)

    Nielsen, Jens Steen; Hansen, Ernst Albin; Sjøgaard, Gisela

    2004-01-01

    The purpose of this study into high-intensity cycling was to: (1) test the hypothesis that endurance time is longest at a freely chosen pedalling rate (FCPR), compared to pedalling rates 25% lower (FCPR-25) and higher (FCPR+25) than FCPR, and (2) investigate how physiological variables......, and endurance time at W90 with FCPR-25, FCPR, and FCPR+25. Power reserve was calculated as the difference between applied power output at a given pedalling rate and peak crank power at this same pedalling rate. W90 was 325 (47) W. FCPR at W90 was 78 (11) rpm, resulting in FCPR-25 being 59 (8) rpm and FCPR+25...... time was negatively related to VO(2max), W90 and % MHC I, while positively related to power reserve. In conclusion, at group level, endurance time was longer at FCPR and at a pedalling rate 25% lower compared to a pedalling rate 25% higher than FCPR. Further, inter-individual physiological variables...

  19. Carbohydrate mouth rinse: does it improve endurance exercise performance?

    Directory of Open Access Journals (Sweden)

    Painelli Vitor

    2010-08-01

    Full Text Available Abstract It is well known that carbohydrate (CHO supplementation can improve performance in endurance exercises through several mechanisms such as maintenance of glycemia and sparing endogenous glycogen as well as the possibility of a central nervous-system action. Some studies have emerged in recent years in order to test the hypothesis of ergogenic action via central nervous system. Recent studies have demonstrated that CHO mouth rinse can lead to improved performance of cyclists, and this may be associated with the activation of brain areas linked to motivation and reward. These findings have already been replicated in other endurance modalities, such as running. This alternative seems to be an attractive nutritional tool to improve endurance exercise performance.

  20. Endurance performance and nocturnal HRV indices.

    Science.gov (United States)

    Nummela, A; Hynynen, E; Kaikkonen, P; Rusko, H

    2010-03-01

    The effects of endurance training on endurance performance characteristics and cardiac autonomic modulation during night sleep were investigated. Twenty-four sedentary subjects trained over four weeks two hours per week at an average running intensity of 76+/-4% of their heart rate reserve. The R to R ECG-intervals were recorded and heart rate variability indices including high frequency power (HFP) were calculated for the nights following the training days every week. The subjects were divided into responders and non-responders according to the improvements in the maximal velocity of the incremental treadmill test (v(max)). The responders improved their v(max) by 10.9+/-46 % (p < 0.001) while no changes were observed in the non-responders (1.6+/-3.0%), although there were no differences in any training load variables between the groups. In the responders nocturnal HFP was significantly higher during the fourth training week compared to the first training week (p=0.036). Furthermore, a significant correlation was observed between the change in v(max) and the change in nocturnal HFP (r=0.482, p=0.042). It was concluded that after similar training, an increase in cardiac vagal modulation was related to improved v(max) in the sedentary subjects. Georg Thieme Verlag KG Stuttgart.New York.

  1. THE RELATIONSHIP BETWEEN TRUNK MUSCLES ENDURANCE AND NORMAL BMI AMONG UNIVERSITY STUDENTS WITH SEDENTARY LIFESTYLE

    Directory of Open Access Journals (Sweden)

    Karthikeyan Selvaganapathy

    2017-12-01

    Full Text Available Background: The most important trunk stabilizers are the trunk flexors and extensors. The isometric endurance of the trunk muscles is an essential element for mechanical support of the spine in all positions. The study objectives were to find out the trunk flexors and extensors endurance, its relationship with normal BMI and to find out the ratio of trunk flexors to extensors endurance. Methods: In this correlation study, 50 subjects were selected by convenience sampling method on the basis of inclusion and exclusion criteria from Asia metropolitan university, Malaysia. The trunk flexors and extensors endurance were assessed by Kraus- Weber and Sorenson test respectively. Paired 't' test and Spearman correlation test were used for data analysis. Results: There was a significant difference (p 0.01 and TEE, rs (50 = -0.162, p >0.01 but there was a significant strong positive relationship between TFE and TEE, rs (50 = 0.68, p < 0.01. The ratio of trunk flexors to extensors was 0.61. Conclusion: The trunk extensors endurance is higher than trunk flexors endurance and BMI has no relationship with trunk flexors and extensors muscle endurance. The ratio of trunk flexors to extensors endurance value is low

  2. Maximal fat oxidation rates in endurance trained and untrained women

    DEFF Research Database (Denmark)

    Stisen, A.B.; Stougaard, O.; Langfort, J.

    2006-01-01

    The aim of the present study was to examine the differences in fat oxidation between endurance trained (ET) and untrained (UT) women. Eight ET and nine UT women performed a progressive cycle ergometer test until exhaustion. The rate of fat oxidation was similar at low work rates (...

  3. Instructions to Adopt an External Focus Enhance Muscular Endurance

    Science.gov (United States)

    Marchant, David C.; Greig, Matt; Bullough, Jonathan; Hitchen, Daniel

    2011-01-01

    The influence of internal (movement focus) and external (outcome focus) attentional-focusing instructions on muscular endurance were investigated using three exercise protocols with experienced exercisers. Twenty-three participants completed a maximal repetition, assisted bench-press test on a Smith's machine. An external focus of attention…

  4. No Evidence of a Common DNA Variant Profile Specific to World Class Endurance Athletes

    Science.gov (United States)

    Wolfarth, Bernd; Wang, Guan; Sarzynski, Mark A.; Alexeev, Dmitry G.; Ahmetov, Ildus I.; Boulay, Marcel R.; Cieszczyk, Pawel; Eynon, Nir; Filipenko, Maxim L.; Garton, Fleur C.; Generozov, Edward V.; Govorun, Vadim M.; Houweling, Peter J.; Kawahara, Takashi; Kostryukova, Elena S.; Kulemin, Nickolay A.; Larin, Andrey K.; Maciejewska-Karłowska, Agnieszka; Miyachi, Motohiko; Muniesa, Carlos A.; Murakami, Haruka; Ospanova, Elena A.; Padmanabhan, Sandosh; Pavlenko, Alexander V.; Pyankova, Olga N.; Santiago, Catalina; Sawczuk, Marek; Scott, Robert A.; Uyba, Vladimir V.; Yvert, Thomas; Perusse, Louis; Ghosh, Sujoy; Rauramaa, Rainer; North, Kathryn N.; Lucia, Alejandro; Pitsiladis, Yannis; Bouchard, Claude

    2016-01-01

    There are strong genetic components to cardiorespiratory fitness and its response to exercise training. It would be useful to understand the differences in the genomic profile of highly trained endurance athletes of world class caliber and sedentary controls. An international consortium (GAMES) was established in order to compare elite endurance athletes and ethnicity-matched controls in a case-control study design. Genome-wide association studies were undertaken on two cohorts of elite endurance athletes and controls (GENATHLETE and Japanese endurance runners), from which a panel of 45 promising markers was identified. These markers were tested for replication in seven additional cohorts of endurance athletes and controls: from Australia, Ethiopia, Japan, Kenya, Poland, Russia and Spain. The study is based on a total of 1520 endurance athletes (835 who took part in endurance events in World Championships and/or Olympic Games) and 2760 controls. We hypothesized that world-class athletes are likely to be characterized by an even higher concentration of endurance performance alleles and we performed separate analyses on this subsample. The meta-analysis of all available studies revealed one statistically significant marker (rs558129 at GALNTL6 locus, p = 0.0002), even after correcting for multiple testing. As shown by the low heterogeneity index (I2 = 0), all eight cohorts showed the same direction of association with rs558129, even though p-values varied across the individual studies. In summary, this study did not identify a panel of genomic variants common to these elite endurance athlete groups. Since GAMES was underpowered to identify alleles with small effect sizes, some of the suggestive leads identified should be explored in expanded comparisons of world-class endurance athletes and sedentary controls and in tightly controlled exercise training studies. Such studies have the potential to illuminate the biology not only of world class endurance performance but

  5. No Evidence of a Common DNA Variant Profile Specific to World Class Endurance Athletes.

    Directory of Open Access Journals (Sweden)

    Tuomo Rankinen

    Full Text Available There are strong genetic components to cardiorespiratory fitness and its response to exercise training. It would be useful to understand the differences in the genomic profile of highly trained endurance athletes of world class caliber and sedentary controls. An international consortium (GAMES was established in order to compare elite endurance athletes and ethnicity-matched controls in a case-control study design. Genome-wide association studies were undertaken on two cohorts of elite endurance athletes and controls (GENATHLETE and Japanese endurance runners, from which a panel of 45 promising markers was identified. These markers were tested for replication in seven additional cohorts of endurance athletes and controls: from Australia, Ethiopia, Japan, Kenya, Poland, Russia and Spain. The study is based on a total of 1520 endurance athletes (835 who took part in endurance events in World Championships and/or Olympic Games and 2760 controls. We hypothesized that world-class athletes are likely to be characterized by an even higher concentration of endurance performance alleles and we performed separate analyses on this subsample. The meta-analysis of all available studies revealed one statistically significant marker (rs558129 at GALNTL6 locus, p = 0.0002, even after correcting for multiple testing. As shown by the low heterogeneity index (I2 = 0, all eight cohorts showed the same direction of association with rs558129, even though p-values varied across the individual studies. In summary, this study did not identify a panel of genomic variants common to these elite endurance athlete groups. Since GAMES was underpowered to identify alleles with small effect sizes, some of the suggestive leads identified should be explored in expanded comparisons of world-class endurance athletes and sedentary controls and in tightly controlled exercise training studies. Such studies have the potential to illuminate the biology not only of world class endurance

  6. Training modalities: impact on endurance capacity.

    Science.gov (United States)

    Flueck, Martin; Eilers, Wouter

    2010-03-01

    Endurance athletes demonstrate an exceptional resistance to fatigue when exercising at high intensity. Much research has been devoted to the contribution of aerobic capacity for the economy of endurance performance. Important aspects of the fine-tuning of metabolic processes and power output in the endurance athlete have been overlooked. This review addresses how training paradigms exploit bioenergetic pathways in recruited muscle groups to promote the endurance phenotype. A special focus is laid on the genome-mediated mechanisms that underlie the conditioning of fatigue resistance and aerobic performance by training macrocycles and complements. The available data on work-induced muscle plasticity implies that different biologic strategies are exploited in athletic and untrained populations to boost endurance capacity. Olympic champions are probably endowed with a unique constitution that renders the conditioning of endurance capacity for competition particularly efficient. Copyright 2010 Elsevier Inc. All rights reserved.

  7. Effects of a 12-Week Hatha Yoga Intervention on Cardiorespiratory Endurance, Muscular Strength and Endurance, and Flexibility in Hong Kong Chinese Adults: A Controlled Clinical Trial

    Directory of Open Access Journals (Sweden)

    Caren Lau

    2015-01-01

    Full Text Available Objective. To examine the effects of a 12-week Hatha yoga intervention on cardiorespiratory endurance, muscular strength and endurance, and flexibility in Chinese adults. Methods. 173 adults (aged 52.0 ± 7.5 years were assigned to either the yoga intervention group (n=87 or the waitlist control group (n=86. 19 dropped out from the study. Primary outcomes were changes in cardiorespiratory endurance (resting heart rate (HR and maximal oxygen uptake (VO2max, muscular strength and endurance (curl-up and push-up tests, and lower back and hamstring flexibility (the modified back-saver sit-and-reach (MBS test. Results. Compared to controls, the yoga group achieved significant improvements in VO2max (P<0.01, curl-up (P<0.05 and push-up (P<0.001 tests, and the MBS left and right leg tests (both P<0.001 in both genders. Significant change was also found for resting HR between groups in women (P<0.05 but not in men. Further analysis comparing participants between younger and older subgroups yielded similar findings, except that the older participants in the yoga group failed to improve resting HR or the curl-up test versus control. Adherence (89% and attendance (94% were high. No serious adverse events occurred. Conclusion. A 12-week Hatha yoga intervention has favorable effects on cardiorespiratory endurance, muscular strength and endurance, and flexibility in Chinese adults.

  8. Primarily Experimental Results for a W Wire Array Z Pinch

    International Nuclear Information System (INIS)

    Kuai Bin; Aici, Qiu; Wang Liangping; Zeng Zhengzhong; Wang Wensheng; Cong Peitian; Gai Tongyang; Wei Fuli; Guo Ning; Zhang Zhong

    2006-01-01

    Primarily experimental results are given for a W wire array Z pinch imploded with up to 2 MA in 100 ns on a Qiangguang-I pulsed power generator. The configuration and parameters of the generator, the W wire array load assembly and the diagnostic system for the experiment are described. The total X-ray energy has been obtained with a averaged power of X-ray radiation of 1.28 TW

  9. Endurance capacity of mice selectively bred for high voluntary wheel running.

    Science.gov (United States)

    Meek, Thomas H; Lonquich, Brian P; Hannon, Robert M; Garland, Theodore

    2009-09-15

    Mice from four lines bred for high voluntary wheel activity run approximately 3-fold more revolutions per day and have elevated maximal oxygen consumption during forced treadmill exercise, as compared with four unselected control (C) lines. We hypothesized that these high runner (HR) lines would have greater treadmill endurance-running capacity. Ninety-six mice from generation 49 were familiarized with running on a motorized treadmill for 3 days. On days 4 and 5, mice were given an incremental speed test (starting at 20 m min(-1), increased 1.5 m min(-1) every 2 min) and endurance was measured as the total time or distance run to exhaustion. Blood samples were taken to measure glucose and lactate concentrations at rest during the photophase, during peak nightly wheel running, and immediately following the second endurance test. Individual differences in endurance time were highly repeatable between days (r=0.79), and mice tended to run longer on the second day (paired t-test, Pwheel running and treadmill endurance differed between the sexes, reinforcing previous studies that indicate sex-specific responses to selective breeding. HR mice appear to have a higher endurance capacity than reported in the literature for inbred strains of mice or transgenics intended to enhance endurance.

  10. Air Force Research Laboratory Spacecraft Cryocooler Endurance Evaluation Update: FY98-99

    National Research Council Canada - National Science Library

    Tomlinson, B

    1999-01-01

    The need for long term endurance evaluation data on space cryocoolers has long been an issue due to the 10-year plus design life of this technology and the absence of any accepted accelerated testing methodology...

  11. Swift Ultra Long Endurance (SULE) Unmanned Air Vehicle (UAV), Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Swift proposes to design, fabricate, and fly a Swift Ultra Long Endurance (SULE) 30-day mission HALE UAS with flight tests including: 24-hrs, 48-hrs, and 7-days...

  12. Effect of salbutamol on neuromuscular function in endurance athletes.

    Science.gov (United States)

    Decorte, Nicolas; Bachasson, Damien; Guinot, Michel; Flore, Patrice; Levy, Patrick; Verges, Samuel; Wuyam, Bernard

    2013-10-01

    The potential ergogenic effects of therapeutic inhaled salbutamol doses in endurance athletes have been controversially discussed for decades. We hypothesized that salbutamol inhalation may increase peripheral muscle contractility, reduce fatigability, and improve force recovery after a localized exercise in endurance athletes. Eleven healthy, nonasthmatic male athletes with high aerobic capacities were recruited to be compared in a double-blinded, randomized crossover study of two dose levels of salbutamol (200 and 800 μg) and a placebo administered by inhalation before a quadriceps fatigue test. Subjects performed an incremental exercise protocol consisting in sets of 10 intermittent isometric contractions starting at 20% of maximum voluntary contraction (MVC) with 10% MVC increment until exhaustion. Femoral nerve magnetic stimulation was used during and after MVC to evaluate neuromuscular fatigue after each set, at task failure, and after 10 and 30 min of recovery. Initial MVC and evoked muscular responses were not modified with salbutamol (P > 0.05). The total number of submaximal contractions until task failure significantly differed between treatments (placebo, 72 ± 7; 200 µg, 78 ± 8; and 800 µg, 82 ± 7; P 0.05). Voluntary activation was unaffected by the fatiguing task and treatments (P > 0.05). Supratherapeutic inhaled doses of β2-agonists increased quadriceps endurance during an incremental and localized fatiguing task in healthy endurance-trained athletes without significant effect on neuromuscular fatigue. Further studies are needed to clarify the underlying mechanisms.

  13. Peculiarities of endurance development for first year students

    Directory of Open Access Journals (Sweden)

    A.G. Pochernina

    2014-06-01

    Full Text Available Purpose: to determine the dynamics of the specific endurance first-year students in the classroom of physical education. Material : the study involved 20 students. Conducted educational testing: seed of lifting in supine position, hang on bent arms, jumping from sitting up with the stop, run 30m, bending and straightening the arms in emphasis lying, tilt forward from a sitting position, shuttle run, broad jump start. Results : found that the passage of the training module volleyball observed development of specific endurance and all motor abilities. Established that the manifestation and development of motor skills are interrelated. Since force is a functional foundation for the development of other skills, flexibility - the foundation of all mechanical movements. Without the development of strength, speed, coordination abilities impossible to develop endurance. Therefore, it is inappropriate and incorrect receipt of unidirectional only specific endurance (dynamic power and static, speed-power. Conclusions: indicated the need to achieve functional specialization of the body in the direction which is necessary for high-level manifestation of certain motor skills.

  14. Neck muscle endurance and head posture: A comparison between adolescents with and without neck pain.

    Science.gov (United States)

    Oliveira, Ana Carolina; Silva, Anabela G

    2016-04-01

    The main aims of this study were to compare the neck flexor and extensor endurance and forward head posture between adolescents with and without neck pain. The secondary aims were to explore potential associations between muscles endurance, head posture and neck pain characteristics and to assess intra-rater reliability of the measurements used. Adolescents with neck pain (n = 35) and age-matched asymptomatic adolescents (n = 35) had their forward head posture, neck flexor endurance and neck extensor endurance measured using clinical tests. Intra-rater reliability was also assessed. Forward head posture and neck flexor and extensor endurance tests showed moderate to almost perfect intra-rater reliability (ICC between 0.58 and 0.88). Adolescents with neck pain showed significantly less forward head posture (neck pain = 46.62 ± 4.92; asymptomatic = 44.18°± 3.64°, p > 0.05) and less neck flexor (neck pain = 24.50 ± 23.03s; asymptomatic = 35.89 ± 21.53s, p > 0.05) and extensor endurance (neck pain = 12.6.64 ± 77.94s; asymptomatic = 168.66 ± 74.77s, p > 0.05) than asymptomatic adolescents. Results suggest that changes in posture and neck muscle endurance are a feature of adolescents with neck pain. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Impact of a supervised worksite exercise program on back and core muscular endurance in firefighters.

    Science.gov (United States)

    Mayer, John M; Quillen, William S; Verna, Joe L; Chen, Ren; Lunseth, Paul; Dagenais, Simon

    2015-01-01

    Low back pain is a leading cause of disability in firefighters and is related to poor muscular endurance. This study examined the impact of supervised worksite exercise on back and core muscular endurance in firefighters. A cluster randomized controlled trial was used for this study. The study occurred in fire stations of a municipal fire department (Tampa, Florida). Subjects were 96 full-duty career firefighters who were randomly assigned by fire station to exercise (n = 54) or control (n = 42) groups. Exercise group participants completed a supervised exercise targeting the back and core muscles while on duty, two times per week for 24 weeks, in addition to their usual fitness regimen. Control group participants continued their usual fitness regimen. Back and core muscular endurance was assessed with the Biering-Sorensen test and plank test, respectively. Changes in back and core muscular endurance from baseline to 24 weeks were compared between groups using analysis of covariance and linear mixed effects models. After 24 weeks, the exercise group had 12% greater (p = .021) back muscular endurance and 21% greater (p = .0006) core muscular endurance than did the control group. The exercise intervention did not disrupt operations or job performance. A supervised worksite exercise program was safe and effective in improving back and core muscular endurance in firefighters, which could protect against future low back pain.

  16. Shoulder muscle endurance: the development of a standardized and reliable protocol

    Directory of Open Access Journals (Sweden)

    Roy Jean-Sébastien

    2011-01-01

    Full Text Available Abstract Background Shoulder muscle fatigue has been proposed as a possible link to explain the association between repetitive arm use and the development of rotator cuff disorders. To our knowledge, no standardized clinical endurance protocol has been developed to evaluate the effects of muscle fatigue on shoulder function. Such a test could improve clinical examination of individuals with shoulder disorders. Therefore, the purpose of this study was to establish a reliable protocol for objective assessment of shoulder muscle endurance. Methods An endurance protocol was developed on a stationary dynamometer (Biodex System 3. The endurance protocol was performed in isotonic mode with the resistance set at 50% of each subject's peak torque as measured for shoulder external (ER and internal rotation (IR. Each subject performed 60 continuous repetitions of IR/ER rotation. The endurance protocol was performed by 36 healthy individuals on two separate occasions at least two days apart. Maximal isometric shoulder strength tests were performed before and after the fatigue protocol to evaluate the effects of the endurance protocol and its reliability. Paired t-tests were used to evaluate the reduction in shoulder strength due to the protocol, while intraclass correlation coefficients (ICC and minimal detectable change (MDC were used to evaluate its reliability. Results Maximal isometric strength was significantly decreased after the endurance protocol (P 0.84. Conclusions Changes in muscular performance observed during and after the muscular endurance protocol suggests that the protocol did result in muscular fatigue. Furthermore, this study established that the resultant effects of fatigue of the proposed isotonic protocol were reproducible over time. The protocol was performed without difficulty by all volunteers and took less than 10 minutes to perform, suggesting that it might be feasible for clinical practice. This protocol could be used to induce

  17. APPENDIX TO THE MEASURING OF ENDURANCE OF CADETS IN HANDBALL

    Directory of Open Access Journals (Sweden)

    Dr Dragan Martinović

    2009-11-01

    Full Text Available At the sample of 80 handball cadet contestants aged between 16-17, there has been done an endurance testing in the discipline of running on a track of total of 12 and 6 minutes. The endurance was estimated in meters of the distance run. The aim of this task was to determine coorelation of the results in running on 12 and 6 minutes. The outcome is a total coorelation between the two. Running of the du- ration of 6 minutes is recommended for the trainer`s practice. Testing is more rational. With the application of the regressive analyses it has been determined that there is depenndance between running time and variables: weight, height and BMI

  18. Life-long endurance exercise in humans

    DEFF Research Database (Denmark)

    Mikkelsen, U R; Couppé, C; Karlsen, A

    2013-01-01

    Human aging is associated with a loss of skeletal muscle and an increase in circulating inflammatory markers. It is unknown whether endurance training (Tr) can prevent these changes. Therefore we studied 15 old trained (O-Tr) healthy males and, for comparison, 12 old untrained (O-Un), 10 Young.......05). Most importantly, life-long endurance exercise was associated with a lower level of the inflammatory markers CRP and IL-6 (p... physical endurance activity may play a role in reducing some markers of systemic inflammation, even within the normal range, and in maintaining muscle mass with aging....

  19. Vitamin C and E supplementation hampers cellular adaptation to endurance training in humans: a double-blind, randomised, controlled trial.

    Science.gov (United States)

    Paulsen, Gøran; Cumming, Kristoffer T; Holden, Geir; Hallén, Jostein; Rønnestad, Bent Ronny; Sveen, Ole; Skaug, Arne; Paur, Ingvild; Bastani, Nasser E; Østgaard, Hege Nymo; Buer, Charlotte; Midttun, Magnus; Freuchen, Fredrik; Wiig, Havard; Ulseth, Elisabeth Tallaksen; Garthe, Ina; Blomhoff, Rune; Benestad, Haakon B; Raastad, Truls

    2014-04-15

    In this double-blind, randomised, controlled trial, we investigated the effects of vitamin C and E supplementation on endurance training adaptations in humans. Fifty-four young men and women were randomly allocated to receive either 1000 mg of vitamin C and 235 mg of vitamin E or a placebo daily for 11 weeks. During supplementation, the participants completed an endurance training programme consisting of three to four sessions per week (primarily of running), divided into high-intensity interval sessions [4-6 × 4-6 min; >90% of maximal heart rate (HRmax)] and steady state continuous sessions (30-60 min; 70-90% of HRmax). Maximal oxygen uptake (VO2 max ), submaximal running and a 20 m shuttle run test were assessed and blood samples and muscle biopsies were collected, before and after the intervention. Participants in the vitamin C and E group increased their VO2 max (mean ± s.d.: 8 ± 5%) and performance in the 20 m shuttle test (10 ± 11%) to the same degree as those in the placebo group (mean ± s.d.: 8 ± 5% and 14 ± 17%, respectively). However, the mitochondrial marker cytochrome c oxidase subunit IV (COX4) and cytosolic peroxisome proliferator-activated receptor-γ coactivator 1 α (PGC-1α) increased in the m. vastus lateralis in the placebo group by 59 ± 97% and 19 ± 51%, respectively, but not in the vitamin C and E group (COX4: -13 ± 54%; PGC-1α: -13 ± 29%; P ≤ 0.03, between groups). Furthermore, mRNA levels of CDC42 and mitogen-activated protein kinase 1 (MAPK1) in the trained muscle were lower in the vitamin C and E group than in the placebo group (P ≤ 0.05). Daily vitamin C and E supplementation attenuated increases in markers of mitochondrial biogenesis following endurance training. However, no clear interactions were detected for improvements in VO2 max and running performance. Consequently, vitamin C and E supplementation hampered cellular adaptations in the exercised muscles, and although this did not translate to the performance tests

  20. Avaliação da resistência de força explosiva em voleibolistas através de testes de saltos verticais Assessment of explosive strength-endurance in volleyball players through vertical jumping test

    Directory of Open Access Journals (Sweden)

    Jefferson Eduardo Hespanhol

    2007-06-01

    Full Text Available O propósito deste estudo foi verificar a existência de diferenças entre o teste de salto vertical com natureza contínua de 60 segundos (TSVC e o teste de salto vertical com natureza intermitente de quatro séries de 15 segundos (TSVI. Os dados foram obtidos através de amostra composta por 10 voleibolistas do sexo masculino (19,01 ± 1,36 anos; 191,5 ± 5,36cm; e 81,74 ± 7,45kg, todos com participação voluntária. As variáveis estudadas foram: as estimativas do pico de potência (PP, potência média (PM e o índice de fadiga (IF. O desempenho estimado através dos testes TSVC, com duração de 60 segundos, e o TSVI foi determinado em quatro séries de 15 segundos, com 10 segundos de recuperação entre cada série. Os dados foram determinados através da estatística descritiva e do teste de Wilcoxon; o nível de significância utilizado foi de p The aim of this study was to verify the differences between the continuous jump test of 60 seconds (CJ60 sec and the intermittent jump test of 4 sets of 15 seconds (IJ4x15 sec. The sample was composed of 10 male volleyball players with 19.01 ± 1.36 years, 191.5 ± 5.36 cm height and 81.74 ± 7.45 of body mass, who participated in this research as volunteers. The variables studied were estimated as the peak power (PP, mean power (MP and fatigue index (FI. These performances were measured through tests of vertical jump with duration the 60 seconds and with the performance of 4 sets of 15 seconds with 10 seconds of recovery between the sets. The data were analyzed through descriptive statistics and the Wilcoxon test. The significance level was of p < 0.05. It was possible to analyze that the continuous and the intermittent jump test presented significant differences in MP (p < 0.05, FI (p < 0.01, and in the number of the vertical jump in 60 seconds (p < 0.01, and the height in 60 seconds exercise (p < 0.05. The MP found in IJ4x15sec was significantly higher than in the CJ60 sec in volleyball

  1. Concurrent Development of Endurance Capacity and Explosiveness: Training Characteristics of World-Class Nordic-Combined Athletes.

    Science.gov (United States)

    Tønnessen, Espen; Rasdal, Vegard; Svendsen, Ida S; Haugen, Thomas A; Hem, Erlend; Sandbakk, Øyvind

    2016-07-01

    Performing at an elite level in Nordic combined (NC) requires both the explosiveness required for ski jumping performance and the endurance capacity required for cross-country skiing. To describe the characteristics of world-class NC athletes' training and determine how endurance and non-endurance (ie, strength, power, and ski jumping) training is periodized. Annual training characteristics and the periodization of endurance and non-endurance training were determined by analyzing the training diaries of 6 world-class NC athletes. Of 846 ± 72 annual training hours, 540 ± 37 h were endurance training, with 88.6% being low-, 5.9% moderate-, and 5.5% high-intensity training. While training frequency remained relatively constant, the total training volume was reduced from the general preparatory to the competition phase, primarily due to less low- and moderate-intensity training (P ski-jump-specific training (908 ± 165 ski jumps and ski-jump imitations). The proportion of non-endurance training increased significantly toward the competition phase (P ski-jump training. These data provide novel insight on how successful athletes execute their training and may facilitate more-precise coaching of future athletes in this sport. In addition, this information is of high relevance for the training organization of other sports that require optimization of 2 fundamentally different physical capacities.

  2. Study of speed endurance middle distance runners

    Directory of Open Access Journals (Sweden)

    R.V. Golovaschenko

    2013-12-01

    Full Text Available Purpose : To investigate the boost performance speed endurance runners who specialize in middle-distance running . Material and methods : The study involved team members Vinnytsia region in an amount of 44 people, whose average age was 20,2 ± 2,1 years. Classes are held during the 21-day mesocycle, 5 times a week, twice a day. Things were aimed at enhancing the development of indicators of special speed endurance. Results : The dynamics of the running speed of the model segments that characterize speed endurance athletes. Proved that the improved running 400 meter intervals helps reduce travel time competitive distance of 1500 meters. Conclusion : The use of the program contributes to higher speed endurance, which determines the result in the women's 1,500 meters.

  3. Intelligence Community Programs, Management, and Enduring Issues

    Science.gov (United States)

    2016-11-08

    books, journal papers, conference presentations, working papers, and other electronic and print publications. Intelligence Community Programs... Intelligence Community Programs, Management, and Enduring Issues Anne Daugherty Miles Analyst in Intelligence and National Security Policy...

  4. Effect of resistance training regimens on treadmill running and neuromuscular performance in recreational endurance runners.

    Science.gov (United States)

    Mikkola, Jussi; Vesterinen, Ville; Taipale, Ritva; Capostagno, Benoit; Häkkinen, Keijo; Nummela, Ari

    2011-10-01

    The purpose of this study was to assess the effects of heavy resistance, explosive resistance, and muscle endurance training on neuromuscular, endurance, and high-intensity running performance in recreational endurance runners. Twenty-seven male runners were divided into one of three groups: heavy resistance, explosive resistance or muscle endurance training. After 6 weeks of preparatory training, the groups underwent an 8-week resistance training programme as a supplement to endurance training. Before and after the 8-week training period, maximal strength (one-repetition maximum), electromyographic activity of the leg extensors, countermovement jump height, maximal speed in the maximal anaerobic running test, maximal endurance performance, maximal oxygen uptake ([V·]O(₂max)), and running economy were assessed. Maximal strength improved in the heavy (P = 0.034, effect size ES = 0.38) and explosive resistance training groups (P = 0.003, ES = 0.67) with increases in leg muscle activation (heavy: P = 0.032, ES = 0.38; explosive: P = 0.002, ES = 0.77). Only the heavy resistance training group improved maximal running speed in the maximal anaerobic running test (P = 0.012, ES = 0.52) and jump height (P = 0.006, ES = 0.59). Maximal endurance running performance was improved in all groups (heavy: P = 0.005, ES = 0.56; explosive: P = 0.034, ES = 0.39; muscle endurance: P = 0.001, ES = 0.94), with small though not statistically significant improvements in [V·]O(₂max) (heavy: ES = 0.08; explosive: ES = 0.29; muscle endurance: ES = 0.65) and running economy (ES in all groups running endurance performance. However, both heavy and explosive strength training were beneficial in improving neuromuscular characteristics, and heavy resistance training in particular contributed to improvements in high-intensity running characteristics. Thus, endurance runners should include heavy resistance training in their training programmes to enhance endurance performance, such as

  5. Energy requirements for racing endurance sled dogs*

    OpenAIRE

    Loftus, John P.; Yazwinski, Molly; Milizio, Justin G.; Wakshlag, Joseph J.

    2014-01-01

    Endurance sled dogs have unique dietary energy requirements. At present, there is disparity in the literature regarding energy expenditure and thus energy requirements of these dogs. We sought to further elucidate energy requirements for endurance sled dogs under field conditions. Three sled dog teams completing the 2011 Yukon Quest volunteered to provide diet history. Nutritional content was evaluated and a mock meal was analysed for each team. Race data were obtained from www.yukonquest.com...

  6. Shoulder Girdle Muscles Endurance in Subjects with and without Impingement Syndrome

    Directory of Open Access Journals (Sweden)

    Afsoun Nodehi-Moghadam

    2011-07-01

    Full Text Available Objective: Any minimal alteration in performance and coordination of scapular and glenohumeral muscles has the potential to lead to shoulder joint dysfunction. The impingement syndrome has been reported as is the most common diagnosis of shoulder pain. The purpose of this study was to determine whether endurance deficits could be detected in patients with shoulder impingement. Materials & Methods: By convenient sampling 15 patients with impingement syndrome at average of 45.3 years of age and 15 healthy persons (age 45.8 years through a case–control design participated in the study. Endurance of glenohumeral and scapulothoracic muscles were tested with a hand held dynamometer. Independent t–test was used to statistically analyze different groups. Results: Compared to non–impaired subjects, those with impingement syndrome demonstrated a significantly lower endurance of external rotation, scaption and scapular abduction and upward rotation movements (P<0.05. In impingement syndrome patients, the external–to–internal rotator muscles endurance ratio was significantly lower than the control group (P<0.05. Conclusion: The result of the study suggests that endurance deficit of rotator cuff and scapular upward rotator muscles may be an important aspect of the impingement syndrome. Shoulder girdle muscles endurance should be considered in evaluation and physical therapy of impingement syndrome patients.

  7. The value of enduring environmental surrogates as predictors of estuarine benthic macroinvertebrate assemblages

    Science.gov (United States)

    Wildsmith, Michelle D.; Valesini, Fiona J.; Robinson, Samuel F.

    2017-10-01

    This study tested the extent to which spatial differences in the benthic macroinvertebrate assemblages of a temperate microtidal estuary were 'explained' by the enduring (biophysical) vs non-enduring (water and sediment quality) environmental attributes of a diverse range of habitats, and thus the potential of those environmental surrogates to support faunal prediction. Species composition differed significantly among habitats in each season, with the greatest differences occurring in winter and spring and the least in summer. The pattern of habitat differences, as defined by their enduring environmental characteristics, was significantly and well matched with that in the fauna in each season. In contrast, significant matches between the non-enduring environmental and faunal data were only detected in winter and/or spring, and to a lesser extent. Field validation of the faunal prediction capacity of the biophysical surrogate framework at various 'test' sites throughout the estuary showed good agreement between the actual vs predicted key species. These findings demonstrate that enduring environmental criteria, which can be readily measured from mapped data, provide a better and more cost-effective surrogate for explaining spatial differences in the invertebrate fauna of this system than non-enduring criteria, and are thus a promising basis for faunal prediction. The approaches developed in this study are also readily adapted to any estuary worldwide.

  8. Respiratory Muscle Training and Exercise Endurance at Altitude.

    Science.gov (United States)

    Helfer, Samuel; Quackenbush, Joseph; Fletcher, Michael; Pendergast, David R

    2016-08-01

    Climbing and trekking at altitude are common recreational and military activities. Physiological effects of altitude are hypoxia and hyperventilation. The hyperventilatory response to altitude may cause respiratory muscle fatigue and reduce sustained submaximal exercise. Voluntary isocapnic hyperpnea respiratory muscle training (VIHT) improves exercise endurance at sea level and at depth. The purpose of this study was to test the hypothesis that VIHT would improve exercise time at altitude [3600 m (11,811 ft)] compared to control and placebo groups. Subjects pedaled an ergometer until exhaustion at simulated altitude in a hypobaric chamber while noninvasive arterial saturation (Sao2), ventilation (VE), and oxygen consumption (Vo2) were measured. As expected, Sao2 decreased to 88 ± 4% saturation at rest and to 81 ± 2% during exercise, and was not affected by VIHT. VIHT resulted in a 40% increase in maximal training VE compared to pre-VIHT. Exercise endurance significantly increased 44% after VIHT (P = altitude post-VIHT increased more (49%) for longer (21 min) and decreased less (11% at 25.4 ± 6.7 min). VIHT improved exercise time at altitude and sustained VE. This suggests that VIHT reduced respiratory muscle fatigue and would be useful to trekkers and military personnel working at altitude. Helfer S, Quackenbush J, Fletcher M, Pendergast DR. Respiratory muscle training and exercise endurance at altitutde. Aerosp Med Hum Perform. 2016; 87(8):704-711.

  9. INFLUENCE OF PHYSICAL TRAINING ON CARDIORESPIRATORY ENDURANCE IN PREADOLESCENT AGE

    Directory of Open Access Journals (Sweden)

    Marjan Marinkovic

    2009-01-01

    Full Text Available Cardiorespiratory or aerobic endurance is the ability of the whole body to sustain physical activity for an extended period of time, involving relatively large groups of muscles. The attitudes on the possible impact of training on cardiorespiratory endurance in preadolescents are contradictory. Our study enrolled 195 boys aged 11 to 12 years. Experimental group (n=92 consisted of the children who had been involved with planned and programmed water polo training for at least two years. Control group (n=103 consisted of schoolchildren who only had had regular physical education in schools. Our investigation protocol included standardized anthropometric measurements and tests, performed respecting the appropriate protocols. Statistical analysis of the results demonstrated that there were no significant differences in age and relative values of oxygen consumption (VO2peak. Body height and mass, as well as the skinfold thickness, were significantly higher in experimental group subjects. The values of absolute VO2peak, FVC and FEV1.0 were also significantly higher in the examinees involved with water polo training. These findings stress the importance of a systematic training process even in this early period of growth and development in order for the trainees to acquire important functional advantages. We believe that a properly planned and programmed physical training can significantly contribute to the development of cardiorespiratory endurance even as early as preadolescent age.

  10. Effects of strength training on endurance capacity in top-level endurance athletes

    DEFF Research Database (Denmark)

    Aagaard, Per; Andersen, Jesper L

    2010-01-01

    The effect of concurrent strength (S) and endurance (E) training on adaptive changes in aerobic capacity, endurance performance, maximal muscle strength and muscle morphology is equivocal. Some data suggest an attenuated cardiovascular and musculoskeletal response to combined E and S training......, while other data show unimpaired or even superior adaptation compared with either training regime alone. However, the effect of concurrent S and E training only rarely has been examined in top-level endurance athletes. This review describes the effect of concurrent SE training on short-term and long......-term endurance performance in endurance-trained subjects, ranging from moderately trained individuals to elite top-level athletes. It is concluded that strength training can lead to enhanced long-term (>30 min) and short-term (...

  11. Individual responses to combined endurance and strength training in older adults.

    Science.gov (United States)

    Karavirta, Laura; Häkkinen, Keijo; Kauhanen, Antti; Arija-Blázquez, Alfredo; Sillanpää, Elina; Rinkinen, Niina; Häkkinen, Arja

    2011-03-01

    A combination of endurance and strength training is generally used to seek further health benefits or enhanced physical performance in older adults compared with either of the training modes alone. The mean change within a training group, however, may conceal a wide range of individual differences in the responses. The purpose, therefore, was to examine the individual trainability of aerobic capacity and maximal strength, when endurance and strength training are performed separately or concurrently. For this study, 175 previously untrained volunteers, 89 men and 86 women between the ages of 40 and 67 yr, completed a 21-wk period of either strength training (S) twice a week, endurance training (E) twice a week, combined training (ES) four times per week, or served as controls. Training adaptations were quantified as peak oxygen uptake (VO2peak) in a bicycle ergometer test to exhaustion and maximal isometric bilateral leg extension force (MVC) in a dynamometer. A large range in training responses, similar to endurance or strength training alone, was also observed with combined endurance and strength training in both ΔVO2peak (from -8% to 42%) and ΔMVC (from -12% to 87%). There were no significant correlations between the training responses in VO2peak and MVC in the E, S, or especially in the ES group, suggesting that the same subjects did not systematically increase both aerobic capacity and maximal strength. The goal of combined endurance and strength training--increasing both aerobic capacity and maximal strength simultaneously--was only achieved by some of the older subjects. New means are needed to personalize endurance, strength, and especially combined endurance and strength training programs for optimal individual adaptations.

  12. The Enduring Value of the Physical Examination.

    Science.gov (United States)

    Zaman, Junaid A B

    2018-05-01

    This article focuses exclusively on physical examination (PE) in the context of clinical medicine, that is, the interaction between a health care provider and patient. In essence, there is not only benefit (value) to PE but also that it will last (endure) for some time. Both "enduring" and "value" are explored in more depth with respect to the future integration of PE into the clinical assessment of a patient and how its value extends well beyond current diagnostic/cost-based metrics. Crown Copyright © 2017. Published by Elsevier Inc. All rights reserved.

  13. CEPRAM: Compression for Endurance in PCM RAM

    OpenAIRE

    González Alberquilla, Rodrigo; Castro Rodríguez, Fernando; Piñuel Moreno, Luis; Tirado Fernández, Francisco

    2017-01-01

    We deal with the endurance problem of Phase Change Memories (PCM) by proposing Compression for Endurance in PCM RAM (CEPRAM), a technique to elongate the lifespan of PCM-based main memory through compression. We introduce a total of three compression schemes based on already existent schemes, but targeting compression for PCM-based systems. We do a two-level evaluation. First, we quantify the performance of the compression, in terms of compressed size, bit-flips and how they are affected by e...

  14. Heart rate variability in prediction of individual adaptation to endurance training in recreational endurance runners.

    Science.gov (United States)

    Vesterinen, V; Häkkinen, K; Hynynen, E; Mikkola, J; Hokka, L; Nummela, A

    2013-03-01

    The aim of this study was to investigate whether nocturnal heart rate variability (HRV) can be used to predict changes in endurance performance during 28 weeks of endurance training. The training was divided into 14 weeks of basic training (BTP) and 14 weeks of intensive training periods (ITP). Endurance performance characteristics, nocturnal HRV, and serum hormone concentrations were measured before and after both training periods in 28 recreational endurance runners. During the study peak treadmill running speed (Vpeak ) improved by 7.5 ± 4.5%. No changes were observed in HRV indices after BTP, but after ITP, these indices increased significantly (HFP: 1.9%, P=0.026; TP: 1.7%, P=0.007). Significant correlations were observed between the change of Vpeak and HRV indices (TP: r=0.75, PHRV among recreational endurance runners, it seems that moderate- and high-intensity training are needed. This study showed that recreational endurance runners with a high HRV at baseline improved their endurance running performance after ITP more than runners with low baseline HRV. © 2011 John Wiley & Sons A/S.

  15. Effect of additional speed endurance training on performance and muscle adaptations

    DEFF Research Database (Denmark)

    Gunnarsson, Thomas; Christensen, Peter Møller; Holse, Kris

    2012-01-01

    PURPOSE: The present study examined the effect of additional speed-endurance training during the season on muscle adaptations and performance of trained soccer players. METHODS: Eighteen sub-elite soccer players performed one session with 6-9 30-s intervals at an intensity of 90-95 % ofmaximal...... intensity (speed endurance training; SET) a week for 5 weeks (SET-intervention). Before and after the SET-intervention the players carried out the Yo-Yo intermittent recovery level 2 (Yo- Yo IR2) test, a sprint test (10- and 30-m) and an agility test. In addition, seven of the players had a resting muscle...

  16. Combined strength and endurance training in competitive swimmers.

    Science.gov (United States)

    Aspenes, Stian; Kjendlie, Per-Ludvik; Hoff, Jan; Helgerud, Jan

    2009-01-01

    A combined intervention of strength and endurance training is common practice in elite swimming training, but the scientific evidence is scarce. The influences between strength and endurance training have been investigated in other sports but the findings are scattered. Some state the interventions are negative to each other, some state there is no negative relationship and some find bisected and supplementary benefits from the combination when training is applied appropriately. The aim of this study was to investigate the impact of a combined intervention among competitive swimmers. 20 subjects assigned to a training intervention group (n = 11) or a control group (n = 9) from two different teams completed the study. Anthropometrical data, tethered swimming force, land strength, performance in 50m, 100m and 400m, work economy, peak oxygen uptake, stroke length and stroke rate were investigated in all subjects at pre- and post-test. A combined intervention of maximal strength and high aerobic intensity interval endurance training 2 sessions per week over 11 weeks in addition to regular training were used, while the control group continued regular practice with their respective teams. The intervention group improved land strength, tethered swimming force and 400m freestyle performance more than the control group. The improvement of the 400m was correlated with the improvement of tethered swimming force in the female part of the intervention group. No change occurred in stroke length, stroke rate, performance in 50m or 100m, swimming economy or peak oxygen uptake during swimming. Two weekly dry-land strength training sessions for 11 weeks increase tethered swimming force in competitive swimmers. This increment further improves middle distance swimming performance. 2 weekly sessions of high- intensity interval training does not improve peak oxygen uptake compared with other competitive swimmers. Key pointsTwo weekly sessions of dry land strength training improves the

  17. Endurance exercise training in orthostatic intolerance: a randomized, controlled trial.

    Science.gov (United States)

    Winker, Robert; Barth, Alfred; Bidmon, Daniela; Ponocny, Ivo; Weber, Michael; Mayr, Otmar; Robertson, David; Diedrich, André; Maier, Richard; Pilger, Alex; Haber, Paul; Rüdiger, Hugo W

    2005-03-01

    Orthostatic intolerance is a syndrome characterized by chronic orthostatic symptoms of light-headedness, fatigue, nausea, orthostatic tachycardia, and aggravated norepinephrine levels while standing. The aim of this study was to assess the protective effect of exercise endurance training on orthostatic symptoms and to examine its usefulness in the treatment of orthostatic intolerance. 2768 military recruits were screened for orthostatic intolerance by questionnaire. Tilt-table testing identified 36 cases of orthostatic intolerance out of the 2768 soldiers. Subsequently, 31 of these subjects with orthostatic intolerance entered a randomized, controlled trial. The patients were allocated randomly to either a "training" (3 months jogging) or a "control" group. The influence of exercise training on orthostatic intolerance was assessed by determination of questionnaire scores and tilt-table testing before and after intervention. After training, only 6 individuals of 16 still had orthostatic intolerance compared with 10 of 11 in the control group. The Fisher exact test showed a highly significant difference in diagnosis between the 2 groups (P=0.008) at the end of the study. Analysis of the questionnaire-score showed significant interaction between time and group (P=0.001). The trained subjects showed an improvement in the average symptom score from 1.79+/-0.4 to 1.04+/-0.4, whereas the control subjects showed no significant change in average symptom score (2.09+/-0.6 and 2.14+/-0.5, respectively). Our data demonstrate that endurance exercise training leads to an improvement of symptoms in the majority of patients with orthostatic intolerance. Therefore, we suggest that endurance training should be considered in the treatment of orthostatic intolerance patients.

  18. Endurance- and Resistance-Trained Men Exhibit Lower Cardiovascular Responses to Psychosocial Stress Than Untrained Men.

    Science.gov (United States)

    Gröpel, Peter; Urner, Maren; Pruessner, Jens C; Quirin, Markus

    2018-01-01

    Evidence shows that regular physical exercise reduces physiological reactivity to psychosocial stress. However, previous research mainly focused on the effect of endurance exercise, with only a few studies looking at the effect of resistance exercise. The current study tested whether individuals who regularly participate in either endurance or resistance training differ from untrained individuals in adrenal and cardiovascular reactivity to psychosocial stress. Twelve endurance-trained men, 10 resistance-trained men, and 12 healthy but untrained men were exposed to a standardized psychosocial stressor, the Trier Social Stress Test. Measurements of heart rate, free salivary cortisol levels, and mood were obtained throughout the test and compared among the three groups. Overall, both endurance- and resistance-trained men had lower heart rate levels than untrained men, indicating higher cardiac performance of the trained groups. Trained men also exhibited lower heart rate responses to psychosocial stress compared with untrained men. There were no significant group differences in either cortisol responses or mood responses to the stressor. The heart rate results are consistent with previous studies indicating reduced cardiovascular reactivity to psychosocial stress in trained individuals. These findings suggest that long-term endurance and resistance trainings may be related to the same cardiovascular benefits, without exhibiting strong effects on the cortisol reactivity to stress.

  19. Carbonate fuel cell endurance: Hardware corrosion and electrolyte management status

    Energy Technology Data Exchange (ETDEWEB)

    Yuh, C.; Johnsen, R.; Farooque, M.; Maru, H.

    1993-01-01

    Endurance tests of carbonate fuel cell stacks (up to 10,000 hours) have shown that hardware corrosion and electrolyte losses can be reasonably controlled by proper material selection and cell design. Corrosion of stainless steel current collector hardware, nickel clad bipolar plate and aluminized wet seal show rates within acceptable limits. Electrolyte loss rate to current collector surface has been minimized by reducing exposed current collector surface area. Electrolyte evaporation loss appears tolerable. Electrolyte redistribution has been restrained by proper design of manifold seals.

  20. Carbonate fuel cell endurance: Hardware corrosion and electrolyte management status

    Energy Technology Data Exchange (ETDEWEB)

    Yuh, C.; Johnsen, R.; Farooque, M.; Maru, H.

    1993-05-01

    Endurance tests of carbonate fuel cell stacks (up to 10,000 hours) have shown that hardware corrosion and electrolyte losses can be reasonably controlled by proper material selection and cell design. Corrosion of stainless steel current collector hardware, nickel clad bipolar plate and aluminized wet seal show rates within acceptable limits. Electrolyte loss rate to current collector surface has been minimized by reducing exposed current collector surface area. Electrolyte evaporation loss appears tolerable. Electrolyte redistribution has been restrained by proper design of manifold seals.

  1. Specific balance training included in an endurance-resistance exercise program improves postural balance in elderly patients undergoing haemodialysis.

    Science.gov (United States)

    Frih, Bechir; Mkacher, Wajdi; Jaafar, Hamdi; Frih, Ameur; Ben Salah, Zohra; El May, Mezry; Hammami, Mohamed

    2018-04-01

    The purpose of this study was to evaluate the effects of 6 months of specific balance training included in endurance-resistance program on postural balance in haemodialysis (HD) patients. Forty-nine male patients undergoing HD were randomly assigned to an intervention group (balance training included in an endurance-resistance training, n = 26) or a control group (resistance-endurance training only, n = 23). Postural control was assessed using six clinical tests; Timed Up and Go test, Tinetti Mobility Test, Berg Balance Scale, Unipodal Stance test, Mini-Balance Evaluation Systems Test and Activities Balance Confidence scale. All balance measures increased significantly after the period of rehabilitation training in the intervention group. Only the Timed Up and Go, Berg Balance Scale, Mini-Balance Evaluation Systems Test and Activities Balance Confidence scores were improved in the control group. The ranges of change in these tests were greater in the balance training group. In HD patients, specific balance training included in a usual endurance-resistance training program improves static and dynamic balance better than endurance-resistance training only. Implications for rehabilitation Rehabilitation using exercise in haemodialysis patients improved global mobility and functional abilities. Specific balance training included in usual endurance resistance training program could lead to improved static and dynamic balance.

  2. Carbohydrate Dependence During Prolonged, Intense Endurance Exercise.

    Science.gov (United States)

    Hawley, John A; Leckey, Jill J

    2015-11-01

    A major goal of training to improve the performance of prolonged, continuous, endurance events lasting up to 3 h is to promote a range of physiological and metabolic adaptations that permit an athlete to work at both higher absolute and relative power outputs/speeds and delay the onset of fatigue (i.e., a decline in exercise intensity). To meet these goals, competitive endurance athletes undertake a prodigious volume of training, with a large proportion performed at intensities that are close to or faster than race pace and highly dependent on carbohydrate (CHO)-based fuels to sustain rates of muscle energy production [i.e., match rates of adenosine triphosphate (ATP) hydrolysis with rates of resynthesis]. Consequently, to sustain muscle energy reserves and meet the daily demands of training sessions, competitive athletes freely select CHO-rich diets. Despite renewed interest in high-fat, low-CHO diets for endurance sport, fat-rich diets do not improve training capacity or performance, but directly impair rates of muscle glycogenolysis and energy flux, limiting high-intensity ATP production. When highly trained athletes compete in endurance events lasting up to 3 h, CHO-, not fat-based fuels are the predominant fuel for the working muscles and CHO, not fat, availability becomes rate limiting for performance.

  3. Galectin-3 increase in endurance athletes

    NARCIS (Netherlands)

    Haettasch, Robert; Spethmann, Sebastian; de Boer, Rudolf A.; Ruifrok, Willem P. T.; Schattke, Sebastian; Wagner, Moritz; Schroeckh, Sabrina; Durmus, Tahir; Schimke, Ingolf; Sanad, Wasiem; Baumann, Gert; Borges, Adrian C.; Knebel, Fabian

    2014-01-01

    Background Galectin-3 is a new and promising biomarker for heart failure and myocardial fibrosis. Although endurance exercise is a crucial element in cardiovascular disease prevention, the relationship between exercise and plasma levels of galectin-3 is still unknown. To date, the relationship

  4. Passion and Pacing in Endurance Performance.

    Science.gov (United States)

    Schiphof-Godart, Lieke; Hettinga, Florentina J

    2017-01-01

    Endurance sports are booming, with sports passionates of varying skills and expertise battering city streets and back roads on their weekly or daily exercise rounds. The investments required for performing in endurance exercise are nevertheless considerable, and passion for their sport might explain the efforts endurance athletes are willing to make. Passion may be defined as a strong motivational force and as such might be related to the neurophysiological basis underlying the drive to exercise. A complex relationship between the brain and other systems is responsible for athletes' exercise behavior and thus performance in sports. We anticipate important consequences of athletes' short term choices, for example concerning risk taking actions, on long term outcomes, such as injuries, overtraining and burnout. We propose to consider athletes' type of passion, in combination with neurophysiological parameters, as an explanatory factor inunderstanding the apparent disparity in the regulation of exercise intensity during endurance sports. Previous research has demonstrated that athletes can be passionate toward their sport in either a harmonious or an obsessive way. Although both lead to considerable investments and therefore often to successful performances, obsessive passion may affect athlete well-being and performance on the long run, due to the corresponding inflexible exercise behavior. In this perspective we will thus examine the influence of passion in sport on athletes' short term and long term decision-making and exercise behavior, in particular related to the regulation of exercise intensity, and discuss the expected long term effects of both types of passion for sport.

  5. The Personal Meaning of Participation: Enduring Involvement.

    Science.gov (United States)

    McIntyre, N.

    1989-01-01

    Examines the personal meaning of participation, discussing recreation and consumer behavior literature, the development of an instrument to measure the concept, and the relationship between commitment to camping and choice of campground setting. Personal meaning of participation seems to be best represented by the concept of enduring involvement.…

  6. Neuromuscular function and fatigue resistance of the plantar flexors following short-term cycling endurance training

    Directory of Open Access Journals (Sweden)

    Martin eBehrens

    2015-05-01

    Full Text Available Previously published studies on the effect of short-term endurance training on the neuromuscular function of the plantar flexors have shown that the H-reflex elicited at rest and during weak voluntary contractions was increased following the training regime. However, these studies did not test H-reflex modulation during isometric maximum voluntary contraction (iMVC and did not incorporate a control group in their study design to compare the results of the endurance training group to individuals without the endurance training stimulus. Therefore, this randomized controlled study was directed to investigate the neuromuscular function of the plantar flexors at rest and during iMVC before and after eight weeks of cycling endurance training. Twenty-two young adults were randomly assigned to an intervention group and a control group. During neuromuscular testing, rate of torque development, isometric maximum voluntary torque and muscle activation were measured. Triceps surae muscle activation and tibialis anterior muscle co-activation were assessed by normalized root mean square of the EMG signal during the initial phase of contraction (0-100, 100-200 ms and isometric maximum voluntary contraction of the plantar flexors. Furthermore, evoked spinal reflex responses of the soleus muscle (H-reflex evoked at rest and during iMVC, V-wave, peak twitch torques induced by electrical stimulation of the posterior tibial nerve at rest and fatigue resistance were evaluated. The results indicate that the endurance training did not lead to a significant change in any variable of interest. Data of the present study conflict with the outcome of previously published studies that have found an increase in H-reflex excitability after endurance training. However, these studies had not included a control group in their study design as was the case here. It is concluded that short-term cycling endurance training does not necessarily enhance H-reflex responses and fatigue

  7. The Influence of Creatine Monohydrate on Strength and Endurance After Doing Physical Exercise With Maximum Intensity

    Directory of Open Access Journals (Sweden)

    Asrofi Shicas Nabawi

    2017-11-01

    Full Text Available The purpose of this study was: (1 to analyze the effect of creatine monohydrate to give strength after doing physical exercise with maximum intensity, towards endurance after doing physical exercise with maximum intensity, (2 to analyze the effect of non creatine monohydrate to give strength after doing physical exercise with maximum intensity, towards endurance after doing physical exercise with maximum intensity, (3 to analyze the results of the difference by administering creatine and non creatine on strength and endurance after exercise with maximum intensity. This type of research used in this research was quantitative with quasi experimental research methods. The design of this study was using pretest and posttest control group design, and data analysis was using a paired sample t-test. The process of data collection was done with the test leg muscle strength using a strength test with back and leg dynamometer, sit ups test with 1 minute sit ups, push ups test with push ups and 30 seconds with a VO2max test cosmed quart CPET during the pretest and posttest. Furthermore, the data were analyzed using SPSS 22.0 series. The results showed: (1 There was the influence of creatine administration against the strength after doing exercise with maximum intensity; (2 There was the influence of creatine administration against the group endurance after doing exercise with maximum intensity; (3 There was the influence of non creatine against the force after exercise maximum intensity; (4 There was the influence of non creatine against the group after endurance exercise maximum intensity; (5 The significant difference with the provision of non creatine and creatine from creatine group difference delta at higher against the increased strength and endurance after exercise maximum intensity. Based on the above analysis, it can be concluded that the increased strength and durability for each of the groups after being given a workout.

  8. DIFFERENT ENDURANCE CHARACTERISTICS OF FEMALE AND MALE GERMAN SOCCER PLAYERS

    Directory of Open Access Journals (Sweden)

    C. Baumgart

    2014-08-01

    Full Text Available The aims of the present study were to assess gender differences regarding lactate threshold and intermittent shuttle run performance in female and male soccer players as well as to investigate the relationships between both endurance characteristics in both genders. Fourteen female (1st division and thirteen male (4th division soccer players completed an incremental test (IT to determine running velocities at 2 and 4 mmol · l-1 blood lactate (v2 and v4 and maximum velocity (vmax as well as an interval shuttle run test (ISRT to determine running distance. Based on v2 and v4 and their percentages in relation to vmax, three intensity zones were calculated: a low lactate zone (v4. Female soccer players have a lower v4 (8.2%, vmax (11.3% and ISRT distance (31.6%. No gender difference was found in v2. In contrast to males, ISRT distance correlates with vmax as well as with v2 and v4 in female soccer players. The intensity zones v4 differ between genders. The present study revealed that gender differences increase when the running performance is intermittent including change of directions. In both genders, different relationships between lactate threshold and intermittent shuttle run performance exist. During incremental testing, the running performances of female and male players reflect different distributions of aerobic and anaerobic metabolic pathways. The revealed gender differences should be considered for soccer endurance training.

  9. Nuclear materials stewardship: Our enduring mission

    International Nuclear Information System (INIS)

    Isaacs, T.H.

    1998-01-01

    The US Department of Energy (DOE) and its predecessors have handled a remarkably wide variety of nuclear materials over the past 50 yr. Two fundamental changes have occurred that shape the current landscape regarding nuclear materials. If one recognizes the implications and opportunities, one sees that the stewardship of nuclear materials will be a fundamental and important job of the DOE for the foreseeable future. The first change--the breakup of the Soviet Union and the resulting end to the nuclear arms race--altered US objectives. Previously, the focus was on materials production, weapon design, nuclear testing, and stockpile enhancements. Now the attention is on dismantlement of weapons, excess special nuclear material inventories, accompanying increased concern over the protection afforded to such materials; new arms control measures; and importantly, maintenance of the safety and reliability of the remaining arsenal without testing. The second change was the raised consciousness and sense of responsibility for dealing with the environmental legacies of past nuclear arms programs. Recognition of the need to clean up radioactive contamination, manage the wastes, conduct current operations responsibly, and restore the environment have led to the establishment of what is now the largest program in the DOE. Two additional features add to the challenge and drive the need for recognition of nuclear materials stewardship as a fundamental, enduring, and compelling mission of the DOE. The first is the extraordinary time frames. No matter what the future of nuclear weapons and no matter what the future of nuclear power, the DOE will be responsible for most of the country's nuclear materials and wastes for generations. Even if the Yucca Mountain program is successful and on schedule, it will last more than 100 yr. Second, the use, management, and disposition of nuclear materials and wastes affect a variety of nationally important and diverse objectives, from national

  10. Influence of nitrate supplementation on VO(2) kinetics and endurance of elite cyclists

    DEFF Research Database (Denmark)

    Christensen, Peter Møller; Nyberg, Michael Permin; Bangsbo, Jens

    2013-01-01

    The present study examined if an elevated nitrate intake would improve VO(2) kinetics, endurance, and repeated sprint capacity in elite endurance athletes. Ten highly trained cyclists (72¿±¿4¿mL O(2) /kg/min, mean¿±¿standard deviation) underwent testing for VO(2) kinetics (3¿×¿6¿min at 298¿±¿28¿W...... juice. Plasma NOx (nitrate¿+¿nitrite) levels were higher (P¿......The present study examined if an elevated nitrate intake would improve VO(2) kinetics, endurance, and repeated sprint capacity in elite endurance athletes. Ten highly trained cyclists (72¿±¿4¿mL O(2) /kg/min, mean¿±¿standard deviation) underwent testing for VO(2) kinetics (3¿×¿6¿min at 298¿±¿28¿W......), endurance (120¿min preload followed by a 400-kcal time trial), and repeated sprint capacity (6¿×¿20¿s sprints, recovery 100¿s) during two 6-day periods in randomized order with a daily ingestion of either 0.5¿L beetroot (BR) juice to increase nitrate levels or a 0.5¿L placebo (PLA) drink with blackcurrant...

  11. Change in the level of strength and endurance development of 5-6 grades pupils under cheerleading exercises influence

    Directory of Open Access Journals (Sweden)

    Tetyana Bala

    2015-06-01

    Full Text Available Purpose: determine the degree of change in the level of strength and endurance development of 5-6 grades pupils under cheerleading exercises influence. Material and Methods: theoretical analysis and generalization of scientific and methodical literature, pedagogical testing, pedagogical experiment and mathematical statistics methods. Results: parameters of strength and endurance development level are presented with their degree of change under cheerleading exercises influence for 5-6 grades pupils of secondary school. Conclusions: cheerleading exercises usage has positive influence on demonstrated strength and endurance degree of secondary school children by all investigated parameters.

  12. COMBINED STRENGTH AND ENDURANCE TRAINING IN COMPETITIVE SWIMMERS

    Directory of Open Access Journals (Sweden)

    Stian Aspenes

    2009-09-01

    Full Text Available A combined intervention of strength and endurance training is common practice in elite swimming training, but the scientific evidence is scarce. The influences between strength and endurance training have been investigated in other sports but the findings are scattered. Some state the interventions are negative to each other, some state there is no negative relationship and some find bisected and supplementary benefits from the combination when training is applied appropriately. The aim of this study was to investigate the impact of a combined intervention among competitive swimmers. 20 subjects assigned to a training intervention group (n = 11 or a control group (n = 9 from two different teams completed the study. Anthropometrical data, tethered swimming force, land strength, performance in 50m, 100m and 400m, work economy, peak oxygen uptake, stroke length and stroke rate were investigated in all subjects at pre- and post-test. A combined intervention of maximal strength and high aerobic intensity interval endurance training 2 sessions per week over 11 weeks in addition to regular training were used, while the control group continued regular practice with their respective teams. The intervention group improved land strength, tethered swimming force and 400m freestyle performance more than the control group. The improvement of the 400m was correlated with the improvement of tethered swimming force in the female part of the intervention group. No change occurred in stroke length, stroke rate, performance in 50m or 100m, swimming economy or peak oxygen uptake during swimming. Two weekly dry-land strength training sessions for 11 weeks increase tethered swimming force in competitive swimmers. This increment further improves middle distance swimming performance. 2 weekly sessions of high- intensity interval training does not improve peak oxygen uptake compared with other competitive swimmers

  13. Effects of Heavy Strength Training on Running Performance and Determinants of Running Performance in Female Endurance Athletes

    Science.gov (United States)

    Vikmoen, Olav; Raastad, Truls; Seynnes, Olivier; Bergstrøm, Kristoffer; Ellefsen, Stian; Rønnestad, Bent R.

    2016-01-01

    Purpose The purpose of the current study was to investigate the effects of adding strength training to normal endurance training on running performance and running economy in well-trained female athletes. We hypothesized that the added strength training would improve performance and running economy through altered stiffness of the muscle-tendon complex of leg extensors. Methods Nineteen female endurance athletes [maximal oxygen consumption (VO2max): 53±3 ml∙kg-1∙min-1, 5.8 h weekly endurance training] were randomly assigned to either normal endurance training (E, n = 8) or normal endurance training combined with strength training (E+S, n = 11). The strength training consisted of four leg exercises [3 x 4–10 repetition maximum (RM)], twice a week for 11 weeks. Muscle strength, 40 min all-out running distance, running performance determinants and patellar tendon stiffness were measured before and after the intervention. Results E+S increased 1RM in leg exercises (40 ± 15%) and maximal jumping height in counter movement jump (6 ± 6%) and squat jump (9 ± 7%, p running economy, fractional utilization of VO2max or VO2max. There were also no change in running distance during a 40 min all-out running test in neither of the groups. Conclusion Adding heavy strength training to endurance training did not affect 40 min all-out running performance or running economy compared to endurance training only. PMID:26953893

  14. Effect of speed endurance training and reduced training volume on running economy and single muscle fiber adaptations in trained runners.

    Science.gov (United States)

    Skovgaard, Casper; Christiansen, Danny; Christensen, Peter M; Almquist, Nicki W; Thomassen, Martin; Bangsbo, Jens

    2018-02-01

    The aim of the present study was to examine whether improved running economy with a period of speed endurance training and reduced training volume could be related to adaptations in specific muscle fibers. Twenty trained male (n = 14) and female (n = 6) runners (maximum oxygen consumption (VO 2 -max): 56.4 ± 4.6 mL/min/kg) completed a 40-day intervention with 10 sessions of speed endurance training (5-10 × 30-sec maximal running) and a reduced (36%) volume of training. Before and after the intervention, a muscle biopsy was obtained at rest, and an incremental running test to exhaustion was performed. In addition, running at 60% vVO 2 -max, and a 10-km run was performed in a normal and a muscle slow twitch (ST) glycogen-depleted condition. After compared to before the intervention, expression of mitochondrial uncoupling protein 3 (UCP3) was lower (P economy at 60% vVO 2 -max (11.6 ± 0.2 km/h) and at v10-km (13.7 ± 0.3 km/h) was ~2% better (P economy with intense training may be related to changes in expression of proteins linked to energy consuming processes in primarily ST muscle fibers. © 2018 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

  15. Tapering strategies in elite British endurance runners.

    Science.gov (United States)

    Spilsbury, Kate L; Fudge, Barry W; Ingham, Stephen A; Faulkner, Steve H; Nimmo, Myra A

    2015-01-01

    The aim of the study was to explore pre-competition training practices of elite endurance runners. Training details from elite British middle distance (MD; 800 m and 1500 m), long distance (LD; 3000 m steeplechase to 10,000 m) and marathon (MAR) runners were collected by survey for 7 days in a regular training (RT) phase and throughout a pre-competition taper. Taper duration was [median (interquartile range)] 6 (3) days in MD, 6 (1) days in LD and 14 (8) days in MAR runners. Continuous running volume was reduced to 70 (16)%, 71 (24)% and 53 (12)% of regular levels in MD, LD and MAR runners, respectively (P training (MD; 53 (45)%, LD; 67 (23)%, MAR; 64 (34)%, P training intensity was above race speed in LD and MAR runners (112 (27)% and 114 (3)%, respectively, P training undertaken prior to the taper in elite endurance runners is predictive of the tapering strategy implemented before competition.

  16. Plutonium in an enduring fuel cycle

    International Nuclear Information System (INIS)

    Pillay, K.K.S.

    1998-05-01

    Nuclear fuel cycles evolved over the past five decades have allowed many nations of the world to enjoy the benefits of nuclear energy, while contributing to the sustainable consumption of the world's energy resources. The nuclear fuel cycle for energy production suffered many traumas since the 1970s because of perceived risks of proliferation of nuclear weapons. However, the experience of the past five decades has shown that the world community is committed to safeguarding all fissile materials and continuing the use of nuclear energy resources. Decisions of a few nations to discard spent nuclear fuels in geologic formations are contrary to the goals of an enduring nuclear fuel cycle and sustainable development being pursued by the world community. The maintenance of an enduring nuclear fuel cycle is dependent on sensible management of all the resources of the fuel cycle, including spent fuels

  17. CORRELATION BETWEEN BODY MASS INDEX AND HANDGRIP STRENGTH AND HANDGRIP ENDURANCE AMONG YOUNG HEALTHY ADULTS

    Directory of Open Access Journals (Sweden)

    Anupi

    2015-07-01

    Full Text Available BACKGROUND: Physical inactivity has become a serious problem all over the world. Handgrip Strength (a form of isometric static contraction test, is an important test to evaluate the physical fitness and nutritional status of an individua l. A number of factors like a ge, gender, body size, effort, skeletal muscle bulk and contractility may affect the handgrip strength (HGS and handgrip endurance (HGE. AIM: This study was conducted to establish the possible correlation (if any between body mass index and handgrip str ength and endurance among young healthy adults. MATERIALS AND METHODS: A population based cross - sectional study comprising of 200 students (both male and female, age group - 18 - 22 yrs was carried out in the Department of Physiology, Jorhat Medical College. Anthropometric parameters like height and weight were taken to evaluate the BMI and handgrip strength and handgrip endurance were taken by using handgrip dynamometer. According to WHO classification of BMI, subjects were categorized into three groups as un derweight BMI ≤18.5 kg/m 2 , normal weight BMI 18.5 - 24.9 kg/m 2 and overweight BMI≥ 24.9 kg/m 2 . Gender wise difference was analyzed by unpaired t test. Statistical analysis for correlation was done by using Karl Pearson’s Correlation Coefficient denoted by(r. RESULT: Males had higher handgrip strength and handgrip endurance than females. Statistic ally significant correlation was found between BMI and handgrip strength & endurance in underweight & overweight subjects. Gender differences in correlation were observed in correlation between BMI & HGS and HGE. CONCLUSION: The observed influence of BMI a nd gender differences in correlation between BMI and HGS and HGE indicate that besides BMI several other factors like effort, strength, muscular contractility etc . affect muscular strength & endurance in young males and females.

  18. ENDURANCE TRAINING AND GLUTATHIONE-DEPENDENT ANTIOXIDANT DEFENSE MECHANISM IN HEART OF THE DIABETIC RATS

    Directory of Open Access Journals (Sweden)

    Mustafa Atalay

    2003-06-01

    Full Text Available Regular physical exercise beneficially influences cardiac antioxidant defenses in normal rats. The aim of this study was to test whether endurance training can strengthen glutathione-dependent antioxidant defense mechanism and decrease lipid peroxidation in heart of the streptozotocin-induced diabetic rats. Redox status of glutathione in blood of diabetic rats in response to training and acute exercise was also examined. Eight weeks of treadmill training increased the endurance in streptozotocin-induced diabetic rats. It did not affect glutathione level in heart tissue at rest and also after exercise. On the other hand, endurance training decreased glutathione peroxidase activity in heart, while glutathione reductase and glutathione S-transferase activities were not affected either by acute exhaustive exercise or endurance training. Reduced and oxidized glutathione levels in blood were not affected by either training or acute exercise. Conjugated dienes levels in heart tissue were increased by acute exhaustive exercise and also 8 weeks treadmill training. Longer duration of exhaustion in trained group may have contributed to the increased conjugated dienes levels in heart after acute exercise. Our results suggest that endurance type exercise may make heart more susceptible to oxidative stress. Therefore it may be wise to combine aerobic exercise with insulin treatment to prevent its adverse effects on antioxidant defense in heart in patients with diabetes mellitus

  19. Arctigenin Efficiently Enhanced Sedentary Mice Treadmill Endurance

    Science.gov (United States)

    Chen, Jing; Yu, Liang; Hu, Lihong; Jiang, Hualiang; Shen, Xu

    2011-01-01

    Physical inactivity is considered as one of the potential risk factors for the development of type 2 diabetes and other metabolic diseases, while endurance exercise training could enhance fat oxidation that is associated with insulin sensitivity improvement in obesity. AMP-activated protein kinase (AMPK) as an energy sensor plays pivotal roles in the regulation of energy homeostasis, and its activation could improve glucose uptake, promote mitochondrial biogenesis and increase glycolysis. Recent research has even suggested that AMPK activation contributed to endurance enhancement without exercise. Here we report that the natural product arctigenin from the traditional herb Arctium lappa L. (Compositae) strongly increased AMPK phosphorylation and subsequently up-regulated its downstream pathway in both H9C2 and C2C12 cells. It was discovered that arctigenin phosphorylated AMPK via calmodulin-dependent protein kinase kinase (CaMKK) and serine/threonine kinase 11(LKB1)-dependent pathways. Mice treadmill based in vivo assay further indicated that administration of arctigenin improved efficiently mice endurance as reflected by the increased fatigue time and distance, and potently enhanced mitochondrial biogenesis and fatty acid oxidation (FAO) related genes expression in muscle tissues. Our results thus suggested that arctigenin might be used as a potential lead compound for the discovery of the agents with mimic exercise training effects to treat metabolic diseases. PMID:21887385

  20. Arctigenin efficiently enhanced sedentary mice treadmill endurance.

    Directory of Open Access Journals (Sweden)

    Xuan Tang

    Full Text Available Physical inactivity is considered as one of the potential risk factors for the development of type 2 diabetes and other metabolic diseases, while endurance exercise training could enhance fat oxidation that is associated with insulin sensitivity improvement in obesity. AMP-activated protein kinase (AMPK as an energy sensor plays pivotal roles in the regulation of energy homeostasis, and its activation could improve glucose uptake, promote mitochondrial biogenesis and increase glycolysis. Recent research has even suggested that AMPK activation contributed to endurance enhancement without exercise. Here we report that the natural product arctigenin from the traditional herb Arctium lappa L. (Compositae strongly increased AMPK phosphorylation and subsequently up-regulated its downstream pathway in both H9C2 and C2C12 cells. It was discovered that arctigenin phosphorylated AMPK via calmodulin-dependent protein kinase kinase (CaMKK and serine/threonine kinase 11(LKB1-dependent pathways. Mice treadmill based in vivo assay further indicated that administration of arctigenin improved efficiently mice endurance as reflected by the increased fatigue time and distance, and potently enhanced mitochondrial biogenesis and fatty acid oxidation (FAO related genes expression in muscle tissues. Our results thus suggested that arctigenin might be used as a potential lead compound for the discovery of the agents with mimic exercise training effects to treat metabolic diseases.

  1. Influence of Endurance Training During Childhood on Total Hemoglobin Mass.

    Science.gov (United States)

    Prommer, Nicole; Wachsmuth, Nadine; Thieme, Ina; Wachsmuth, Christian; Mancera-Soto, Erica M; Hohmann, Andreas; Schmidt, Walter F J

    2018-01-01

    Elite endurance athletes are characterized by markedly increased hemoglobin mass (Hbmass). It has been hypothesized that this adaptation may occur as a response to training at a very young age. Therefore, the aim of this study was to monitor changes in Hbmass in children aged 8-14 years following systematic endurance training. In the first study, Hbmass, VO2max, and lean body mass (LBM) were measured in 17 endurance-trained children (13 boys and 4 girls; aged 9.7 ± 1.3 years; training history 1.5±1.8 years; training volume 3.5 ± 1.6 h) twice a year for up to 3.5 years. The same parameters were measured once in a control group of 18 age-matched untrained children. Hbmass and blood volume (BV) were measured using the optimized CO-rebreathing technique, VO2max by an incremental test on a treadmill, and LBM by skin-fold measurements. In the second pilot study, the same parameters were measured in 9 young soccer athletes (aged 7.8 ± 0.2 years), and results were assessed in relation to soccer performance 2.5 years later. The increase in mean Hbmass during the period of study was 50% which was closely related to changes in LBM ( r = 0.959). A significant impact of endurance training on Hbmass was observed in athletes exercising more than 4 h/week [+25.4 g compared to the group with low training volume (LBM (11.4 g·kg -1 LBM) and overlapped with the effects of age. A strong relationship was present between absolute Hbmass and VO2max ( r = 0.939), showing that an increase of 1 g hemoglobin increases VO2max by 3.6 ml·min -1 . Study 2 showed a positive correlation between Hbmass and soccer performance 2.5 years later at age 10.3 ± 0.3 years ( r = 0.627, p = 0.035). In conclusion, children with a weekly training volume of more than 4 h show a 7% higher Hbmass than untrained children. Although this training effect is significant and independent of changes in LBM, the major factor driving the increase in Hbmass is still LBM.

  2. Comparison of an Intermittent Hypoxic Exposure Acclimatization Program to Staging at Moderate Altitude on Endurance Performance at 4300 m

    Science.gov (United States)

    2009-10-01

    Endurance Performance at 4300 m 7 - 6 RTO-MP-HFM-181 breakfast volunteers were provided with two commercially available energy bars and fruit juice ...food composition = 510 kcal, 14 gm fat, 65 gm carbohydrate, 32 gm protein) at 1 to 2 hrs prior to the beginning of each of the cycle endurance test...JE, Robinson SR, Skrinar GS, Lewis SF and Sawka MN. Intermittent altitude exposures improve muscular performance at 4,300 m. J Appl Physiol 95

  3. Impairments of postural stability, core endurance, fall index and functional mobility skills in patients with patello femoral pain syndrome.

    Science.gov (United States)

    Yilmaz Yelvar, Gul Deniz; Çirak, Yasemin; Dalkilinç, Murat; Demir, Yasemin Parlak; Baltaci, Gul; Kömürcü, Mahmut; Yelvar, Gul Deniz Yilmaz

    2016-06-30

    Postural control allows performance of daily and sports activities. The previous studies show that postural sway inceases in orthopaedic injuries such as osteoarthritis and total knee arthroplasty. To compare postural sway, risk of falling and function between individuals with and without patellofemoral pain syndrome (PFS). This study included 22 subjects with patellofemoral pain syndrome, age-matched pain-free 22 females serving as a control group. Visual anolog scale and Kujala were used to evaluate the pain. Posturographic assesment was performed by Tetrax posturographic device. Biering Modified Sorenson test for extensor endurance and sit-up test for flexor endurance were used for the evaluation of trunk endurance. Timed get-up and go test was used for lower extremity function. The Student's t Test was used to compare variables between the groups. The Pearson correlation coefficients were calculated to examine correlation between the quantitative variables. Postural sway included eyes open without pillow, eyes open on pillow, eyes closed on pillow, risk of falling, function and postural stabilization included flexor endurance, extansor endurance are impared in patient with patellofemoral pain syndrome when compare to controls. In subjects with PFPS increased postural sway significantly associated with body mass index (r= 0.52), pain duration (r= 0.43), postural control (extansor endurance) (r= -0.50) and risk of falling (r= 0.62) on pillow with open eyes. In addition we found function significantly related with postural control (extansor endurance and flexor endurance) (r= -0.59 and r= -0.59) and risk of falling (r= 0.77)CONCLUSIONS: Decreased neuromuscular control of the trunk core and increased postural sway and falling risk were found in patients with PFPS. Patients may be evaluated for deficits in postural control and falling risk before treatment.

  4. Antarctic crabs: invasion or endurance?

    Directory of Open Access Journals (Sweden)

    Huw J Griffiths

    Full Text Available Recent scientific interest following the "discovery" of lithodid crabs around Antarctica has centred on a hypothesis that these crabs might be poised to invade the Antarctic shelf if the recent warming trend continues, potentially decimating its native fauna. This "invasion hypothesis" suggests that decapod crabs were driven out of Antarctica 40-15 million years ago and are only now returning as "warm" enough habitats become available. The hypothesis is based on a geographically and spatially poor fossil record of a different group of crabs (Brachyura, and examination of relatively few Recent lithodid samples from the Antarctic slope. In this paper, we examine the existing lithodid fossil record and present the distribution and biogeographic patterns derived from over 16,000 records of Recent Southern Hemisphere crabs and lobsters. Globally, the lithodid fossil record consists of only two known specimens, neither of which comes from the Antarctic. Recent records show that 22 species of crabs and lobsters have been reported from the Southern Ocean, with 12 species found south of 60 °S. All are restricted to waters warmer than 0 °C, with their Antarctic distribution limited to the areas of seafloor dominated by Circumpolar Deep Water (CDW. Currently, CDW extends further and shallower onto the West Antarctic shelf than the known distribution ranges of most lithodid species examined. Geological evidence suggests that West Antarctic shelf could have been available for colonisation during the last 9,000 years. Distribution patterns, species richness, and levels of endemism all suggest that, rather than becoming extinct and recently re-invading from outside Antarctica, the lithodid crabs have likely persisted, and even radiated, on or near to Antarctic slope. We conclude there is no evidence for a modern-day "crab invasion". We recommend a repeated targeted lithodid sampling program along the West Antarctic shelf to fully test the validity of the

  5. Strength Training Prior to Endurance Exercise: Impact on the Neuromuscular System, Endurance Performance and Cardiorespiratory Responses

    Directory of Open Access Journals (Sweden)

    Conceição Matheus

    2014-12-01

    Full Text Available This study aimed to investigate the acute effects of two strength-training protocols on the neuromuscular and cardiorespiratory responses during endurance exercise. Thirteen young males (23.2 ± 1.6 years old participated in this study. The hypertrophic strength-training protocol was composed of 6 sets of 8 squats at 75% of maximal dynamic strength. The plyometric strength-training protocol was composed of 6 sets of 8 jumps performed with the body weight as the workload. Endurance exercise was performed on a cycle ergometer at a power corresponding to the second ventilatory threshold until exhaustion. Before and after each protocol, a maximal voluntary contraction was performed, and the rate of force development and electromyographic parameters were assessed. After the hypertrophic strengthtraining and plyometric strength-training protocol, significant decreases were observed in the maximal voluntary contraction and rate of force development, whereas no changes were observed in the electromyographic parameters. Oxygen uptake and a heart rate during endurance exercise were not significantly different among the protocols. However, the time-to-exhaustion was significantly higher during endurance exercise alone than when performed after hypertrophic strength-training or plyometric strength-training (p <0.05. These results suggest that endurance performance may be impaired when preceded by strength-training, with no oxygen uptake or heart rate changes during the exercise.

  6. Maximal power output during incremental exercise by resistance and endurance trained athletes.

    Science.gov (United States)

    Sakthivelavan, D S; Sumathilatha, S

    2010-01-01

    This study was aimed at comparing the maximal power output by resistance trained and endurance trained athletes during incremental exercise. Thirty male athletes who received resistance training (Group I) and thirty male athletes of similar age group who received endurance training (Group II) for a period of more than 1 year were chosen for the study. Physical parameters were measured and exercise stress testing was done on a cycle ergometer with a portable gas analyzing system. The maximal progressive incremental cycle ergometer power output at peak exercise and carbon dioxide production at VO2max were measured. Highly significant (P biofeedback and perk up the athlete's performance.

  7. Observations of in-reactor endurance and rupture life for fueled and unfueled FTR cladding

    International Nuclear Information System (INIS)

    Lovell, A.J.; Christensen, B.Y.; Chin, B.A.

    1979-01-01

    Reactor component endurance limits are important to nuclear experimenters and operators. This paper investigates endurance limits of 316 CW fuel pin cladding. The objective of this paper is to compare and analyze two different sets of FTR fuel pin cladding data. The first data set is from unfueled pressurized cladding irradiated in the Experimental Breeder Reactor No. II (EBR-II). This data set was generated in an assembly in which the temperature was monitored and controlled. The second data set contains observations of breached and unbreached EBR-II test fuel pins covering a large range of temperature, power and burnup conditions

  8. Hybrid Control of Long-Endurance Aerial Robotic Vehicles for Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Deok-Jin Lee

    2011-06-01

    Full Text Available This paper presents an effective hybrid control approach for building stable wireless sensor networks between heterogeneous unmanned vehicles using long‐ endurance aerial robotic vehicles. For optimal deployment of the aerial vehicles in communication networks, a gradient climbing based self‐estimating control algorithm is utilized to locate the aerial platforms to maintain maximum communication throughputs between distributed multiple nodes. The autonomous aerial robots, which function as communication relay nodes, extract and harvest thermal energy from the atmospheric environment to improve their flight endurance within specified communication coverage areas. The rapidly‐deployable sensor networks with the high‐endurance aerial vehicles can be used for various application areas including environment monitoring, surveillance, tracking, and decision‐making support. Flight test and simulation studies are conducted to evaluate the effectiveness of the proposed hybrid control technique for robust communication networks.

  9. Effect of antioxidant supplementation on insulin sensitivity in response to endurance exercise training

    DEFF Research Database (Denmark)

    Yfanti, Christina; Nielsen, Anders R; Åkerström, Thorbjörn

    2011-01-01

    While production of reactive oxygen and nitrogen species (RONS) is associated with some of the beneficial adaptations to regular physical exercise, it is not established whether RONS play a role in the improved insulin-stimulated glucose uptake in skeletal muscle obtained by endurance training....... To assess the effect of antioxidant supplementation during endurance training on insulin-stimulated glucose uptake, twenty-one young healthy (age 29±1 y; BMI 25±3 Kg m(-2)) men were randomly assigned into either an antioxidant (AO; 500 mg vitamin C and 400 IU vitamin E (a-tocopherol) daily) or a placebo (PL......) group that both underwent a supervised intense endurance-training program, 5 times per week for 12 weeks. A 3-hour euglycemic-hyperinsulinemic clamp, a maximal oxygen consumption (VO(2max)) and maximal power output (P(max)) test, and body composition measurements (fat mass, fat-free mass) were performed...

  10. Independent effects of endurance training and weight loss on peak fat oxidation in moderately overweight men

    DEFF Research Database (Denmark)

    Nordby, Pernille; Rosenkilde, Mads; Ploug, Thorkil

    2015-01-01

    Endurance training increases peak fat oxidation (PFO) during exercise, but whether this is independent of changes in body weight is not known. The aim of the present study was to investigate the effects of endurance training with or without weight loss or a diet-induced weight loss on PFO...... and on key skeletal muscle mitochondrial proteins involved in fat oxidation. Sixty moderately overweight, sedentary but otherwise healthy men were randomized to 12 wk of training (T), diet (D), training and increased caloric intake (T-iD), or continuous sedentary control (C). Isoenergetic deficits...... corresponding to 600 kcal/day were comprised of endurance exercise for T and caloric restriction for D. T-iD completed similar training but was not in 600 kcal deficit because of dietary replacement. PFO and the exercise intensity at which this occurred (FatMax) were measured by a submaximal exercise test...

  11. Emotions and trait emotional intelligence among ultra-endurance runners.

    Science.gov (United States)

    Lane, Andrew M; Wilson, Mathew

    2011-07-01

    The aim of this study was to investigate relationships between trait emotional intelligence and emotional state changes over the course of an ultra-endurance foot race covering a route of approximately 175 miles (282 km) and held in set stages over six days. A repeated measures field design that sought to maintain ecological validity was used. Trait emotional intelligence was defined as a relatively stable concept that should predict adaptive emotional states experienced over the duration of the race and therefore associate with pleasant emotions during a 6-stage endurance event. Thirty-four runners completed a self-report measure of trait emotional intelligence before the event started. Participants reported emotional states before and after each of the six races. Repeated measures ANOVA results showed significant variations in emotions over time and a main effect for trait emotional intelligence. Runners high in self-report trait emotional intelligence also reported higher pleasant and lower unpleasant emotions than runners low in trait emotional intelligence. Findings lend support to the notion that trait emotional intelligence associates with adaptive psychological states, suggesting that it may be a key individual difference that explains why some athletes respond to repeated bouts of hard exercise better than others. Future research should test the effectiveness of interventions designed to enhance trait emotional intelligence and examine the attendant impact on emotional responses to intense exercise during multi-stage events. Copyright © 2011. Published by Elsevier Ltd.

  12. Comparison between two types of anaerobic speed endurance training in competitive soccer players

    Directory of Open Access Journals (Sweden)

    Mohr Magni

    2016-06-01

    Full Text Available The purpose of the present study was to examine the effects of additional in-season speed endurance production versus speed endurance maintenance training regimes on performance in competitive male soccer players. In a randomised controlled trial 18 male sub-elite players were exposed to additional speed endurance production (SEP or speed endurance maintenance (SEM training (two additional sessions/wk for 4 weeks during the competitive season. Players performed the Yo-Yo intermittent recovery level 2 test (YYIR2 and a repeated sprint test (RST pre- and post-intervention. Yo-Yo IR2 performance increased (p<0.001 by 50 ± 8% and 26 ± 5% in SEP and SEM, respectively, with greater (p=0.03 improvement in SEP. RST performance improved by 2.1 ± 0.3% and 1.3 ± 0.4% in SEP and SEM, respectively, while the RST fatigue index decreased (4.4 ± 0.8 to 3.4 ± 0.5%; p<0.04 in SEP only. Peak and average speed during training were higher (p<0.001 in SEP than in SEM (24.5 ± 0.3 vs 19.2 ± 0.3 and 15.5 ± 0.1 km·h-1 vs 9.4 ± 0.1 km·h-1. Additional in-season anaerobic speed endurance production and maintenance training improves high-intensity exercise performance in competitive soccer players with superior effects of speed endurance production training.

  13. Playground Apparatus Experience and Muscular Endurance among Children 4-6.

    Science.gov (United States)

    Gabbard, Carl

    The effects of specific play apparatus experience on a test of upper body muscular endurance was investigated among a group of children 4-6 years old. Both the control and experimental group consisted of 45 subjects randomly selected on the basis of age from two private day care centers situated in the same community. The two groups were of…

  14. Neck Flexor and Extensor Muscle Endurance in Subclinical Neck Pain: Intrarater Reliability, Standard Error of Measurement, Minimal Detectable Change, and Comparison With Asymptomatic Participants in a University Student Population.

    Science.gov (United States)

    Lourenço, Ana S; Lameiras, Carina; Silva, Anabela G

    2016-01-01

    The aims of this study were to assess intrarater reliability and to calculate the standard error of measurement (SEM) and minimal detectable change (MDC) for deep neck flexor and neck extensor muscle endurance tests, and compare the results between individuals with and without subclinical neck pain. Participants were students of the University of Aveiro reporting subclinical neck pain and asymptomatic participants matched for sex and age to the neck pain group. Data on endurance capacity of the deep neck flexors and neck extensors were collected by a blinded assessor using the deep neck flexor endurance test and the extensor endurance test, respectively. Intraclass correlation coefficients (ICCs), SEM, and MDC were calculated for measurements taken within a session by the same assessor. Differences between groups for endurance capacity were investigated using a Mann-Whitney U test. The deep neck flexor endurance test (ICC = 0.71; SEM = 6.91 seconds; MDC = 19.15 seconds) and neck extensor endurance test (ICC = 0.73; SEM = 9.84 minutes; MDC = 2.34 minutes) are reliable. No significant differences were found between participants with and without neck pain for both tests of muscle endurance (P > .05). The endurance capacity of the deep neck flexors and neck extensors can be reliably measured in participants with subclinical neck pain. However, the wide SEM and MDC might limit the sensitivity of these tests. Copyright © 2016. Published by Elsevier Inc.

  15. Disgust sensitivity is primarily associated with purity-based moral judgments.

    Science.gov (United States)

    Wagemans, Fieke M A; Brandt, Mark J; Zeelenberg, Marcel

    2018-03-01

    Individual differences in disgust sensitivity are associated with a range of judgments and attitudes related to the moral domain. Some perspectives suggest that the association between disgust sensitivity and moral judgments will be equally strong across all moral domains (i.e., purity, authority, loyalty, care, fairness, and liberty). Other perspectives predict that disgust sensitivity is primarily associated with judgments of specific moral domains (e.g., primarily purity). However, no study has systematically tested if disgust sensitivity is associated with moral judgments of the purity domain specifically, more generally to moral judgments of the binding moral domains, or to moral judgments of all of the moral domains equally. Across 5 studies (total N = 1,104), we find consistent evidence for the notion that disgust sensitivity relates more strongly to moral condemnation of purity-based transgressions (meta-analytic r = .40) than to moral condemnation of transgressions of any of the other domains (range meta-analytic rs: .07-.27). Our findings are in line with predictions from Moral Foundations Theory, which predicts that personality characteristics like disgust sensitivity make people more sensitive to a certain set of moral issues. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  16. Alterations in redox homeostasis in the elite endurance athlete.

    Science.gov (United States)

    Lewis, Nathan A; Howatson, Glyn; Morton, Katie; Hill, Jessica; Pedlar, Charles R

    2015-03-01

    The production of reactive oxygen (ROS) and nitrogen species (RNS) is a fundamental feature of mammalian physiology, cellular respiration and cell signalling, and essential for muscle function and training adaptation. Aerobic and anaerobic exercise results in alterations in redox homeostasis (ARH) in untrained, trained and well trained athletes. Low to moderate doses of ROS and RNS play a role in muscle adaptation to endurance training, but an overwhelming increase in RNS and ROS may lead to increased cell apoptosis and immunosuppression, fatigued states and underperformance. The objectives of this systematic review are: (a) to test the hypotheses that ARH occur in elite endurance athletes; following an acute exercise bout, in an endurance race or competition; across a micro-, meso- or macro-training cycle; following a training taper; before, during and after altitude training; in females with amenorrhoea versus eumenorrhoea; and in non-functional over-reaching (NFOR) and overtraining states (OTS); (b) to report any relationship between ARH and training load and ARH and performance; and (c) to apply critical difference values for measures of oxidative stress/ARH to address whether there is any evidence of ARH being of physiological significance (not just statistical) and thus relevant to health and performance in the elite athlete. Electronic databases, Embase, MEDLINE, and SPORTDiscus were searched for relevant articles. Only studies that were observational articles of cross-sectional or longitudinal design, and included elite athletes competing at national or international level in endurance sports were included. Studies had to include biomarkers of ARH; oxidative damage, antioxidant enzymes, antioxidant capacity, and antioxidant vitamins and nutrients in urine, serum, plasma, whole blood, red blood cells (RBCs) and white blood cells (WBCs). A total of 3,057 articles were identified from the electronic searches. Twenty-eight articles met the inclusion criteria

  17. Are Ultrasonographic Measures of Cervical Flexor Muscles Correlated With Flexion Endurance in Chronic Neck Pain and Asymptomatic Participants?

    Science.gov (United States)

    Ghamkhar, Leila; Kahlaee, Amir Hossein

    2017-12-01

    This study compared the relationship between some clinical factors and the size of neck flexors in participants with or without chronic neck pain. In this case-control study, the correlation between flexor endurance capacity as well as thickness, cross-section area, and shape ratio of longus colli/capitis and sternocleidomastoid muscles were examined in 30 patients with chronic neck pain and 30 asymptomatic participants. The patients showed lower flexor endurance (P = 0.02), smaller thickness (P = 0.03), and cross-section area (P pain. In the control group, flexor endurance was negatively correlated with longus colli shape ratio (r = -0.45, P = 0.01) but positively correlated with longus capitis thickness (r = 0.45, P = 0.01) and cross-section area (r = 0.38, P = 0.03). Neck disability and pain intensity indices were not significantly correlated with either flexor muscles endurance or size. The ultrasonographic measures of the deep neck flexor muscles and the flexor endurance test, being associated with each other, could successfully differentiate patients with chronic neck pain from asymptomatic participants. However, the endurance test scores were not correlated with self-reported disability or pain intensity indices.

  18. Moderate-intensity endurance training improves endothelial glycocalyx layer integrity in healthy young men.

    Science.gov (United States)

    Majerczak, Joanna; Grandys, Marcin; Duda, Krzysztof; Zakrzewska, Agnieszka; Balcerczyk, Aneta; Kolodziejski, Leszek; Szymoniak-Chochol, Dorota; Smolenski, Ryszard T; Bartosz, Grzegorz; Chlopicki, Stefan; Zoladz, Jerzy A

    2017-01-01

    What is the central question of this study? The main aim of the present study was to determine the effect of prolonged moderate-intensity endurance training on the endothelial glycocalyx layer integrity in relationship to the training-induced changes in oxidative stress and antioxidant defence in humans. What is the main finding and its importance? We have shown, for the first time, a protective effect of prolonged moderate-intensity endurance training on endothelial glycocalyx layer integrity, as judged by significantly lower basal and end-exercise serum concentrations of glycocalyx damage markers, i.e. syndecan-1 and heparan sulfate, accompanied by attenuation of oxidative stress and enhancement of antioxidant defence after training in previously untrained healthy young men. In this study, we evaluated the effect of 20 weeks of moderate-intensity endurance training (ET) on the endothelial glycocalyx layer integrity in relationship to the training-induced changes in antioxidant defence. Eleven healthy young, untrained men performed an incremental cycling exercise bout until exhaustion before and after 20 weeks of ET. Endurance training consisted of 40 min sessions, mainly of moderate intensity (∼50% of maximal oxygen uptake), performed four times per week. Venous blood samples were taken at rest and at the end of the maximal exercise test. Muscle biopsies from vastus lateralis were taken before and after the training. Endurance training resulted in a significant increase in physical capacity (P  0.05). Moderate-intensity ET exerts a pronounced protective effect on endothelial glycocalyx integrity at rest and during exercise, probably through an improvement of antioxidant defence that may represent the vasoprotective mechanisms highly responsive to moderate-intensity endurance training. © 2016 The Authors. Experimental Physiology © 2016 The Physiological Society.

  19. Training of students’ special endurance in ping pong sport circles

    Directory of Open Access Journals (Sweden)

    V.M. Grinko

    2017-04-01

    Full Text Available Urpose: to test experimentally influence of aerobic trainings (cross country training and basic aerobic on students’ special endurance in sport oriented groups (sport circles, ping pong. Material: 106 first year students (n=53 - control group and n=53 - experimental participated in experiment. For determination of temporal series’ trends R-S analysis was used. Prognostication of mistakes’ quantity per one set was fulfilled with the help of exponential smoothing method. Results: it was shown that exponential smoothing method permits to prognosticate by one set ahead with rather high accuracy. As initial predictor we found mean quantity of mistakes in all sets. It permits to average all internal and external factors, which influence on the next predicting indicators. Such approach increases confidence of mistakes’ calculation in prognostication. Criteria of prognostication methodic for possible indicators’ values were also determined. Conclusions: the recommended time distribution in program is as follows: ping pong - 75%; cross country training and basic aerobic - 25%.

  20. Back end of an enduring fuel cycle

    International Nuclear Information System (INIS)

    Pillay, K.K.S.

    1998-03-01

    An enduring nuclear fuel cycle is an essential part of sustainable consumption, the process whereby world's riches are consumed in a responsible manner so that future generations can continue to enjoy at least some of them. In many countries, the goal of sustainable development has focused attention on the benefits of nuclear technologies. However, sustenance of the nuclear fuel cycle is dependent on sensible management of all the resources of the fuel cycle, including energy, spent fuels, and all of its side streams. The nuclear fuel cycle for energy production has suffered many traumas since the mid seventies. The common basis of technologies producing nuclear explosives and consumable nuclear energy has been a preoccupation for some, predicament for others, and a perception problem for many. It is essential to reestablish a reliable back end of the nuclear fuel cycle that can sustain the resource requirements of an enduring full cycle. This paper identifies some pragmatic steps necessary to reverse the trend and to maintain a necessary fuel cycle option for the future

  1. Efficacy of Ashwagandha (Withania somnifera [L.] Dunal) in improving cardiorespiratory endurance in healthy athletic adults.

    Science.gov (United States)

    Choudhary, Bakhtiar; Shetty, A; Langade, Deepak G

    2015-01-01

    Ashwagandha (Withania somnifera [L.] Dunal) has been traditionally used for various actions ranging from vitalizer, improve endurance and stamina, promote longevity, improve immunity, and male and female fertility. However, clinical studies are needed to prove the clinical efficacy of this herb, especially in cardiovascular endurance and physical performance. This prospective, double-blind, randomized, and placebo-controlled study evaluated the efficacy of Ashwagandha roots extract in enhancing cardiorespiratory endurance and improving the quality of life (QOL) in 50 healthy male/female athletic adults. Cardiorespiratory endurance was assessed by measuring the oxygen consumption at peak physical exertion (VO2 max) levels during a 20 m shuttle run test. The World Health Organization self-reported QOL questionnaire (physical health, psychological health, social relationships, and environmental factors) was used to assess the QOL. Student's t-test was used to compare the differences in a mean and change from baseline VO2 max levels, whereas Wilcoxon signed-rank test was used to assess changes in QOL scores from baseline in the two groups. There was a greater increase from baseline (P < 0.0001) in the mean VO2 max with KSM-66 Ashwagandha (n = 24) compared to placebo (n = 25) at 8 weeks (4.91 and 1.42, respectively) and at 12 weeks (5.67 and 1.86 respectively). The QOL scores for all subdomains significantly improved to a greater extent in the Ashwagandha group at 12 weeks compared to placebo (P < 0.05). The findings suggest that Ashwagandha root extract enhances the cardiorespiratory endurance and improves QOL in healthy athletic adults.

  2. Veterinary problems of endurance horses in England and Wales.

    Science.gov (United States)

    Nagy, A; Dyson, S J; Murray, J K

    2017-05-01

    Several studies have shown that a considerable proportion of horses are eliminated from endurance rides due to lameness and metabolic problems. Limited information is available on specific veterinary issues in endurance horses and there are no descriptive data on veterinary problems in a large population of endurance horses. The aim of this study was to describe veterinary problems occurring in endurance horses in England and Wales, the regions of the United Kingdom where endurance rides are organised and regulated by Endurance Great Britain (Endurance GB). A comprehensive online self-completed questionnaire was used for data collection (30th December 2015-29th February 2016) All members of Endurance GB who were the main rider of one or more endurance horses were eligible to participate. From the target population of 1209 horses, 190 questionnaires were completed by riders, resulting in a 15.7% response rate. The most common rider-reported veterinary problem was lameness, affecting 152/190 (80.0%) of endurance horses at some point during their careers and 101/190 (53.2%) of horses in the previous 12 months. Detailed information on the most recent episode of lameness was available for 147 horses. Seventy-six percent of these lameness episodes (112/147) had been initially identified by a veterinarian, but only 52% of these lameness episodes were investigated further by a veterinarian, despite the high proportion of horses affected by lameness and the proportion of horses with recurrent lameness episodes. The second most common veterinary problem was thoracolumbar region pain, followed by non-specific cough, skin disease and colic. Education of endurance riders may improve the number, quality and timing of veterinary investigations, especially for lameness and thoracolumbar region pain. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Comparison of Brain-Derived Neurotrophic Factor (BDNF and Insulin-like Growth Factor 1 (IGF-1 Responses to Different Endurance Training Intensities in Runner Men

    Directory of Open Access Journals (Sweden)

    M. Habibian

    2017-04-01

    Full Text Available Aims: Blood neurotrophins, such as Brain-Derived Neurotrophic Factor (BDNF and Insulin-like Growth Factor 1 (IGF-1, mediate exercise- induced health benefits in humans. The purpose of this study was to compare the response of BDNF and IGF-1 to different endurance training intensities in runner men. Materials & Methods: In this semi-experimental study with pre-test-posttest design in 2015, 10 people of male runners from Gorgan were selected through purposeful and accessible sampling. The endurance training protocol was 6 km running with moderate (70-75% of heart rate reserve or severe (80-85% of heart rate reserve intensity, which was performed within a week's interval. Fasting blood samples were collected before and immediately after both acute training sessions and serum levels of BDNF and IGF-1 were measured by ELISA and radioimmunoassay enzyme. Data were analyzed by SPSS 20 software using independent t-test and paired t-test. Findings: Both acute endurance training significantly increased serum levels of BDNF and IGF-1 in runners, but high intensity endurance exercises increased BDNF levels in comparison with moderate intensity (p0.05. Conclusion: Serum BDNF response in endurance athletes is affected by the intensity of exercise, so that the effect of high intensity endurance training on BDNF levels is greater than moderate intensity exercise, but the response of IGF-1 to acute endurance training is independent of the intensity of exercise.

  4. A Typology of Marital Quality of Enduring Marriages in Israel

    Science.gov (United States)

    Cohen, Orna; Geron, Yael; Farchi, Alva

    2010-01-01

    This article presents a typology of enduring marriages of Israeli couples married for at least 40 years. Based on the view that marital quality is a multidimensional phenomenon, the typology is derived from a cluster analysis of responses of husbands and wives in 51 couples to the ENRICH scale items. Three types of enduring marriages were found:…

  5. The human endurance athlete: heterogeneity and adaptability of ...

    African Journals Online (AJOL)

    In human subjects, large variations between individuals (up to 3-fold) exist in the capacity for endurance exercise performance. In a heterogeneous population, endurance performance is strongly related to whole body maximal oxygen uptake (VO2 max). This is in part genotype dependent (~25%) but is adaptable with ...

  6. Upper Body Muscular Endurance Among Children 2-5 Years.

    Science.gov (United States)

    Gabbard, Carl P.; And Others

    The upper body muscular endurance of males and females 2-5 years of age was assessed, and relationships relative to sex, age, endurance and selected anthropometric measures were investigated. None of the relationships were found to be of practical predicative value; while upper body muscular strength increased with age, no significant differences…

  7. Nutritional habits among high-performance endurance athletes

    Directory of Open Access Journals (Sweden)

    Marius Baranauskas

    2015-01-01

    Conclusions: The diet of highly trained endurance athletes does not fully meet their requirements and in this situation cannot ensure maximum adaptation to very intense and/or long-duration physical loads. The diet of highly trained endurance athletes must be optimized, adjusted and individualized. Particular attention should be focused on female athletes.

  8. Endurance Factors Improve Hippocampal Neurogenesis and Spatial Memory in Mice

    Science.gov (United States)

    Kobilo, Tali; Yuan, Chunyan; van Praag, Henriette

    2011-01-01

    Physical activity improves learning and hippocampal neurogenesis. It is unknown whether compounds that increase endurance in muscle also enhance cognition. We investigated the effects of endurance factors, peroxisome proliferator-activated receptor [delta] agonist GW501516 and AICAR, activator of AMP-activated protein kinase on memory and…

  9. Comparative analysis of endurance of not hearing and hearing students

    Directory of Open Access Journals (Sweden)

    Iwańska Dagmara

    2013-11-01

    Full Text Available Study aim: Sport participation is important for deaf children, as participants experience physical, psychological and social benefits [23]. This study is a summary of four year’s researches on the endurance level of deaf and well hearing girls and boys. The aim of this study was to compare endurance of not hearing and hearing students.

  10. Influence of stress and recovery on endurance performance indicators

    NARCIS (Netherlands)

    Otter, Ruby; Brink, Michel; Lemmink, Koen

    2016-01-01

    Endurance athletes seek for the optimal balance in stress and recovery so that they can perform at their best. However, it is still largely unknown how psychosocial stress and recovery influence performance indicators of endurance athletes. Therefore, the aim of the study was to investigate how

  11. Development of bacoside enriched date syrup juice and its evaluation for physical endurance.

    Science.gov (United States)

    Anand, T; Prakash, K Bhanu; Pandareesh, M D; Khanum, Farhath

    2014-12-01

    Bacoside rich juice (BRJ) was developed using date syrup as base. BRJ was evaluated for physicochemical, sensory attributes and its effect on physical endurance. Overall acceptability of BRJ and date syrup juice (DSJ) was good according to hedonic scale/ratings. Twenty four adult male Wistar rats were divided into 4 groups (n = 6). Sedentary (Group I) and control (Group II) group rats were allowed to drink water whereas DSJ and BRJ group rats were provided free access to drink DSJ (Group III) and BRJ (Group IV) for 14 days and were subjected to weight-loaded forced swim test (WFST) for every alternate day in order to evaluate the physical endurance. Both BRJ and DSJ group rats swimming efficiency was improved by 3 and 2 folds respectively in comparison with control group on day- 15. Improved physical endurance in BRJ group is due to reduced malondialdehyde levels in brain, liver and muscle tissues by 16.50 %, 17.88 % and 30.20 %, respectively, compared to DSJ group (p < 0.01). In addition, administration of BRJ significantly protected the hepatic and muscle glycogen levels and reduced the levels of lactic acid in comparison to DSJ group. Hence, the present study clearly indicates that BRJ is an effective anti-fatigue drink ameliorates the various impairments associated with physical endurance.

  12. High-intensity endurance training increases nocturnal heart rate variability in sedentary participants

    Directory of Open Access Journals (Sweden)

    A Nummela

    2016-01-01

    Full Text Available The effects of endurance training on endurance performance characteristics and cardiac autonomic modulation during night sleep were investigated during two 4-week training periods. After the first 4-week training period (3 x 40 min per week, at 75% of HRR the subjects were divided into HIGH group (n = 7, who performed three high-intensity endurance training sessions per week; and CONTROL group (n = 8 who did not change their training. An incremental treadmill test was performed before and after the two 4-weektraining periods. Furthermore, nocturnal RR-intervals were recorded after each training day. In the second 4-weektraining period HIGH group increased their V0Zmax (P = 0.005 more than CONTROL group. At the same time, nocturnal HR decreased (P = 0.039 and high-frequency power (HFP increased (P = 0.003 in HIGH group while no changes were observed in CONTROL group. Furthermore, a correlation was observed between the changes in nocturnal HFP and changes in V0Zmax during the second 4-week training period (r = 0.90, P < 0.001. The present study showed that the increased HFP is related to improved VO2max in sedentary subjects suggesting that nocturnal HFP can provide a useful method in monitoring individual responses to endurance training.

  13. The effects of neural mobilization on cervical radiculopathy patients' pain, disability, ROM, and deep flexor endurance.

    Science.gov (United States)

    Kim, Dong-Gyu; Chung, Sin Ho; Jung, Ho Bal

    2017-09-22

    Cervical radiculopathy (CR) is a disease of the cervical spine and a space-occupying lesion that occurs because of pathological problems with cervical nerve roots. Nerve root injury to produce functional disability. The purpose of this study was to examine the effects of neural mobilization with manual cervical traction (NMCT) compared with manual cervical traction (MCT) on pain, functional disability, muscle endurance, and range of motion (ROM) in individuals with CR patients. A blinded randomized clinical trial was conducted. Thirty CR patients were divided into two groups - those who received NMCT and those who received MCT. The intervention was applied three times per week for eight weeks. It was measured in order to determine the pain and functional disability in patients with CR. The numeric pain rating scale (NPRS), neck disability index (NDI), ROM, and deep flexor endurance of patients were measured prior to the experiment, four weeks, and eight weeks after the experiment to compare the time points. A repeated-measures analysis of variance was used to compare differences within each group prior to the experiment. And Bonferroni test was performed to examine the significance of each time point. There were significant differences within each group prior to the intervention, four weeks after the intervention, and eight weeks after the intervention in NPRS, NDI, ROM, and deep flexor endurance (Ppain relief, recovery from neck disability, ROM, and deep flexor endurance for patients with CR.

  14. Short term endurance results on a single cylinder diesel engine fueled with upgraded bio oil biodiesel emulsion

    Science.gov (United States)

    Prakash, R.; Murugan, S.

    2017-11-01

    This paper deliberates the endurance test outcomes obtained from a single cylinder, diesel engine fueled with an upgraded bio oil biodiesel emulsion. In this investigation a bio oil obtained by pyrolysis of woody biomass was upgraded with acid treatment. The resulted bio oil was emulsified with addition of biodiesel and suitable surfactant which is termed as ATJOE15. The main objective of the endurance test was to evaluate the wear characteristics of the engine components and lubrication oil properties, when the engine is fueled with the ATJOE15 emulsion. The photographic views taken before and after the end of 100 hrs endurance test, and visual inspection of the engine components, wear and carbon deposit results, are discussed in this paper.

  15. The enduring scientific contributions of Sigmund Freud.

    Science.gov (United States)

    Gedo, John E

    2002-01-01

    Through the development of a novel observational method, Sigmund Freud made possible the collection of reliable data about man's inner life. The scientific hypotheses he formulated about these formed the initial version of psychoanalysis. Many of these first thoughts have had to be revised in the light of subsequent scientific findings about the operations of the central nervous system, but even these refuted propositions often had much heuristic value. Despite the passage of a whole century, many Freudian hypotheses have retained their scientific standing. Most important among these was Freud's realization that human thought is usually unconscious. His understanding of the role of the automatic repetition of basic patterns of behavior, of the fateful consequences of early childhood emotional vicissitudes in structuring enduring mental dispositions, and of the distinction between two distinct modes of thinking are the most significant among his many contributions.

  16. Endurance exercise after orange ingestion anaphylaxis

    Directory of Open Access Journals (Sweden)

    Manu Gupta

    2016-01-01

    Full Text Available Endurance exercise after orange ingestion cause anaphylaxis which is food-dependent exercise-induced anaphylaxis (FDEIA which is a form of exercise-induced anaphylaxis. In this article, an individual develops symptoms such as flushing, itching, urticaria, angioedema, and wheezing after eating a food allergen and proceeds to exercise. Neither the food alone nor exercise alone is sufficient to induce a reaction. This case report describes a 36-year-old asthmatic male athlete who experienced nausea, vomiting, flushing, urticaria, and facial swelling while exercising in a gymnasium after eating oranges. Neither oranges alone nor exercise alone induced the reaction. Total avoidance of suspected food allergens would be ideal. Persons with FDEIA should keep at hand an emergency kit with antihistamines, injectable rapid action corticoids, and adrenaline.

  17. Effects of muscular endurance training on musculoskeletal disorders in teachers

    Directory of Open Access Journals (Sweden)

    Elisângela Valevein Rodrigues

    Full Text Available AbstractIntroduction Physical exercise is indicated to reduce the incidence of musculoskeletal symptoms in teachers.Objective To evaluate the effects of muscular endurance training on muscle strength and musculoskeletal symptoms related to the lower limbs of public elementary school teachers.Materials and methods Thirty-one female teachers were divided into two groups: control (CG, n = 15 and muscular endurance training (TG, n = 16. The training consisted of two sets of 15 repetitions of exercises for quadriceps and hamstring muscle groups, twice a week, for 7 weeks, which were conducted with 50% of 10 repetition maximum(10RM (first to fourth week and 60% of 10 RM (fifth to seventh week. Musculoskeletal symptoms (Nordic Musculoskeletal Questionnaire, isometric peak torque (Load cell and muscle strength (10RM were assessed before and after intervention. ANOVA for repeated measures and Tukey post hoc were used to analyse strength and peak torque of quadriceps and hamstrings and Chi-square goodness-of-fit test were used to analyse the frequency of occurrence of osteomuscular symptoms.Results The highest incidence of symptoms was found in the lumbar region in both groups. Training caused increased muscle strength of the quadriceps and hamstrings, but there were no significant differences in either the peak torque in the quadriceps and hamstrings or in the reduction of musculoskeletal symptoms.Conclusion The exercise program performed in this study increased the dynamic strength in the TG in relation to the CG, but did not alter the incidence of symptoms in the lumbar region and lower limbs in neither of the groups. Thus, results suggest that the duration of intervention may not have been enough to increase peak torque and decrease musculoskeletal symptoms.

  18. Metabolic characteristics of keto-adapted ultra-endurance runners.

    Science.gov (United States)

    Volek, Jeff S; Freidenreich, Daniel J; Saenz, Catherine; Kunces, Laura J; Creighton, Brent C; Bartley, Jenna M; Davitt, Patrick M; Munoz, Colleen X; Anderson, Jeffrey M; Maresh, Carl M; Lee, Elaine C; Schuenke, Mark D; Aerni, Giselle; Kraemer, William J; Phinney, Stephen D

    2016-03-01

    Many successful ultra-endurance athletes have switched from a high-carbohydrate to a low-carbohydrate diet, but they have not previously been studied to determine the extent of metabolic adaptations. Twenty elite ultra-marathoners and ironman distance triathletes performed a maximal graded exercise test and a 180 min submaximal run at 64% VO2max on a treadmill to determine metabolic responses. One group habitually consumed a traditional high-carbohydrate (HC: n=10, %carbohydrate:protein:fat=59:14:25) diet, and the other a low-carbohydrate (LC; n=10, 10:19:70) diet for an average of 20 months (range 9 to 36 months). Peak fat oxidation was 2.3-fold higher in the LC group (1.54±0.18 vs 0.67±0.14 g/min; P=0.000) and it occurred at a higher percentage of VO2max (70.3±6.3 vs 54.9±7.8%; P=0.000). Mean fat oxidation during submaximal exercise was 59% higher in the LC group (1.21±0.02 vs 0.76±0.11 g/min; P=0.000) corresponding to a greater relative contribution of fat (88±2 vs 56±8%; P=0.000). Despite these marked differences in fuel use between LC and HC athletes, there were no significant differences in resting muscle glycogen and the level of depletion after 180 min of running (-64% from pre-exercise) and 120 min of recovery (-36% from pre-exercise). Compared to highly trained ultra-endurance athletes consuming an HC diet, long-term keto-adaptation results in extraordinarily high rates of fat oxidation, whereas muscle glycogen utilization and repletion patterns during and after a 3 hour run are similar. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  19. Quantitative and Qualitative Criteria for Assessing Endurance in Women over 60 Years of Age – Findings from a Pilot Study

    Directory of Open Access Journals (Sweden)

    Kortas Jakub

    2016-09-01

    Full Text Available Introduction. If it is to be effective, health training needs to be monitored based on regular and periodic assessment. The norms that have been proposed for standardised endurance tests for the 60-plus age group, particularly for women, still require evaluation. In light of the above, we have undertaken to design quantitative and qualitative criteria for assessing the level of endurance. Such criteria are urgently needed by persons working with this age group. Material and methods. We developed a quantitative and qualitative system for evaluating endurance based on Zatsiorky’s model, and we verified it in a group of 90 women aged over 60 years. We analysed data measured directly during a 2-km walk test. Results. We developed a set of quantitative and qualitative criteria for assessing endurance in women aged over 60 years based on the results of a 2-km walk test, measured on a scale ranging from 24:18 to 15:52 min:s. Conclusion. The pilot study has proven that a scale based on Zatsiorsky’s model can be an effective tool for assessing endurance in women aged over 60 years. We can thus recommend that it be widely used in practice. It is important to compare these results with the norms for the group in question and to establish comprehensive norms that could be useful for persons who organise physical activity for older adults.

  20. Effects of a strength endurance training program on endurance levels Efectos de un programa de entrenamiento de la fuerza-resistencia sobre los niveles de resistencia

    Directory of Open Access Journals (Sweden)

    J. C. Redondo

    2010-09-01

    Full Text Available

    The purpose of the current study was to determine whether a strength endurance training program of lower limbs isolate can increase endurance levels, both aerobic capacity and aerobic power, in order to adapt the strength training for endurance races. 20 phisically active men participated in the study. They were divided into two groups: control group (GC (n=10 and experimental group (GE (n=10. GE carried out a strength endurance training program for ten weeks. Results obtained showed that this type of training regime was useful to improve the performance in an aerobic endurance test. This could be due to an improvement in aerobic capacity, maximal dynamic strength, explosive strength and reactive strength. Moreover, there was a decrease in fat mass without increase in muscle mass.
    Key Words:  Training, strength endurance, aerobic capacity, anthropometry.

     

    El presente estudio pretende comprobar que el trabajo aislado de la fuerza resistencia en miembros inferiores produce una mejora de los niveles de resistencia, en términos tanto de potencia como de capacidad aeróbica, optimizando así el entrenamiento de la fuerza para pruebas de resistencia de media y larga duración. Para ello, veinte sujetos participaron en el estudio, dividiéndose de forma aleatoria en dos grupos: grupo control (GC (n=10 y grupo experimental (GE (n=10 el cual llevó a cabo un entrenamiento de fuerza resistencia extensivo por intervalos, de diez semanas de duración. Los resultados obtenidos muestran que este tipo de entrenamiento es efectivo para mejorar el rendimiento en una prueba de resistencia aeróbica para sujetos físicamente activos, gracias a la mejora de la capacidad aeróbica, de la fuerza máxima dinámica, elástico explosiva y elástico explosivo reactiva y a la disminución de los niveles de grasa

  1. Characterisation of baroreflex sensitivity of recreational ultra-endurance athletes.

    Science.gov (United States)

    Foulds, Heather J A; Cote, Anita T; Phillips, Aaron A; Charlesworth, Sarah A; Bredin, Shannon S D; Burr, Jamie F; Drury, Chipman Taylor; Ngai, Shirley; Fougere, Renee J; Ivey, Adam C; Warburton, Darren E R

    2014-01-01

    Altered autonomic function has been identified following ultra-endurance event participation among elite world-class athletes. Despite dramatic increases in recreational athlete participation in these ultra-endurance events, the physiological effects on these athletes are less known. This investigation sought to characterise changes in surrogate measures of autonomic function: heart rate variability (HRV), blood pressure variability (BPV) and baroreceptor sensitivity (BRS) following ultra-endurance race participation. Further, we sought to compare baseline measures among ultra-endurance athletes and recreationally active controls not participating in the ultra-endurance race. Recreational ultra-endurance athletes (n = 25, 44.6 ± 8.2 years, 8 females) and recreationally active age, sex and body mass index matched controls (n = 25) were evaluated. Measurements of HRV, BPV and BRS were collected pre- and post-race for recreational ultra-endurance athletes and at baseline, for recreationally active controls. Post-race, ultra-endurance athletes demonstrated significantly greater sympathetic modulation [low frequency (LF) power HRV: 50.3 ± 21.6 normalised units (n.u.) to 65.9 ± 20.4 n.u., p = 0.01] and significantly lower parasympathetic modulation [high frequency (HF) power HRV: 45.0 ± 22.4 n.u. to 23.9 ± 13.1 n.u., p HRV and BPV measures. Recreational ultra-endurance athletes experienced increased sympathetic tone and declines in BRS post-race, similar to previously reported elite world-class ultra-endurance athletes, though still within normal population ranges.

  2. Limiar anaeróbio e velocidade crítica determinada com diferentes distâncias em nadadores de 10 a 15 anos: relações com a performance e a resposta do lactato sanguíneo em testes de endurance Anaerobic threshold and critical speed determined with different distances in swimmers aged 10 to 15 years: relationship with the performance and blood lactate response during endurance tests

    Directory of Open Access Journals (Sweden)

    Camila Coelho Greco

    2003-02-01

    Full Text Available O objetivo deste estudo foi comparar a velocidade crítica (VC determinada através de diferentes distâncias com o limiar anaeróbio (LAn e as velocidades máximas mantidas em testes de 20 (V20 e 30 (V30 minutos na natação, verificando se a idade cronológica em jovens nadadores interfere nessas relações. Participaram do estudo 31 nadadores (17 meninas e 14 meninos divididos segundo a idade cronológica em dois grupos: 10 a 12 anos e 13 a 15 anos. O LAn foi determinado como sendo a velocidade correspondente a 4mM de lactato sanguíneo. A VC1 (25/50/100m, VC2 (100/200/400m e a VC3 (50/100/200m foram calculadas através do coeficiente angular da reta de regressão linear entre as distâncias e seus respectivos tempos. As V20 e V30 foram determinadas através de três a seis repetições, com coletas de sangue no 10º minuto e ao final do tiro. Para o grupo de 10 a 12 anos, a VC1 (m/s (0,98 ± 0,17 e o LAn (0,97 ± 0,12 não foram diferentes entre si, sendo maiores do que a VC2 (0,92 ± 0,16, VC3 (0,89 ± 0,18, V20 (0,92 ± 0,11 e V30 (0,90 ± 0,11. Para o grupo de 13 a 15 anos, a VC1 (m/s(1,11 ± 0,11 foi maior do que o LAn (1,02 ± 0,07, V20 (0,99 ± 0,09, V30 (0,97 ± 0,09, VC2 (0,98 ± 0,11 e VC3 (1,00 ± 0,11. Pode-se concluir que a distância utilizada na determinação da VC interfere no valor obtido, independente da idade cronológica. A VC determinada com distâncias entre 50 e 400m pode ser utilizada na avaliação da capacidade aeróbia de crianças e adolescentes, substituindo os testes contínuos máximos com durações próximas a 20 ou 30 minutos.The objective of this study was to compare the critical speed (CS determined from different distances with the anaerobic threshold (AnT and the maximum speeds in tests of 20 (S20 and 30 (S30 minutes, and to check if the chronological age of young swimmers can influence these relations. 31 swimmers (17 girls and 14 boys participated in this study, divided by chronological age into two

  3. Effect of speed endurance and strength training on performance, running economy and muscular adaptations in endurance-trained runners

    DEFF Research Database (Denmark)

    Vorup Petersen, Jacob; Tybirk, Jonas; Gunnarsson, Thomas Petursson

    2016-01-01

    PURPOSE: To investigate the effects of combined strength and speed endurance (SE) training along with a reduced training volume on performance, running economy and muscular adaptations in endurance-trained runners. METHODS: Sixteen male endurance runners (VO2-max: ~60 ml kg(-1) min(-1)) were rand...... and speed endurance training, along with a reduced training volume, can improve short-term exercise capacity and induce muscular adaptations related to anaerobic capacity in endurance-trained runners.......PURPOSE: To investigate the effects of combined strength and speed endurance (SE) training along with a reduced training volume on performance, running economy and muscular adaptations in endurance-trained runners. METHODS: Sixteen male endurance runners (VO2-max: ~60 ml kg(-1) min(-1)) were...... randomly assigned to either a combined strength and SE training (CSS; n = 9) or a control (CON; n = 7) group. For 8 weeks, CSS replaced their normal moderate-intensity training (~63 km week(-1)) with SE (2 × week(-1)) and strength training (2 × week(-1)) as well as aerobic high (1 × week(-1)) and moderate...

  4. Effects of curative treatment emphasizing endurance training on the performance and blood pressure of hypertensive and normotensives

    Science.gov (United States)

    Worms, F.

    1981-01-01

    The problem of normal values of blood pressure after exercise taking into account the blood pressure at the end of the exercise test is discussed. Hypertensives showed a lower working capacity than normotensives. In normotensives, however, systolic blood pressure at the end of an exercise correlated well with the working capacity. After the endurance cure submaximal blood pressure was markedly lower in hypertensives with a striking dependence on the level of initial values. Systolic blood pressure at the end of an exercise test was not changed significantly. Most probably it is not possible to overcome this malregulation in hypertensives by endurance training alone.

  5. Nitric oxide circulates in mammalian plasma primarily as an S-nitroso adduct of serum albumin.

    Science.gov (United States)

    Stamler, J S; Jaraki, O; Osborne, J; Simon, D I; Keaney, J; Vita, J; Singel, D; Valeri, C R; Loscalzo, J

    1992-01-01

    We have recently shown that nitric oxide or authentic endothelium-derived relaxing factor generated in a biologic system reacts in the presence of specific protein thiols to form S-nitrosoprotein derivatives that have endothelium-derived relaxing factor-like properties. The single free cysteine of serum albumin, Cys-34, is particularly reactive toward nitrogen oxides (most likely nitrosonium ion) under physiologic conditions, primarily because of its anomalously low pK; given its abundance in plasma, where it accounts for approximately 0.5 mM thiol, we hypothesized that this plasma protein serves as a reservoir for nitric oxide produced by the endothelial cell. To test this hypothesis, we developed a methodology, which involves UV photolytic cleavage of the S--NO bond before reaction with ozone for chemiluminescence detection, with which to measure free nitric oxide, S-nitrosothiols, and S-nitrosoproteins in biologic systems. We found that human plasma contains approximately 7 microM S-nitrosothiols, of which 96% are S-nitrosoproteins, 82% of which is accounted for by S-nitroso-serum albumin. By contrast, plasma levels of free nitric oxide are only in the 3-nM range. In rabbits, plasma S-nitrosothiols are present at approximately 1 microM; 60 min after administration of NG-monomethyl-L-arginine at 50 mg/ml, a selective and potent inhibitor of nitric oxide synthetases, S-nitrosothiols decreased by approximately 40% (greater than 95% of which were accounted for by S-nitrosoproteins, and approximately 80% of which was S-nitroso-serum albumin); this decrease was accompanied by a concomitant increase in mean arterial blood pressure of 22%. These data suggest that naturally produced nitric oxide circulates in plasma primarily complexed in S-nitrosothiol species, principal among which is S-nitroso-serum albumin. This abundant, relatively long-lived adduct likely serves as a reservoir with which plasma levels of highly reactive, short-lived free nitric oxide can be

  6. Effects of Cycling Versus Running Training on Sprint and Endurance Capacity in Inline Speed Skating

    Directory of Open Access Journals (Sweden)

    Carolin Stangier, Thomas Abel, Julia Mierau, Wildor Hollmann, Heiko K. Strüder

    2016-03-01

    Full Text Available The purpose of this study was to compare the effects of running versus cycling training on sprint and endurance capacity in inline speed skating. Sixteen elite athletes (8 male, 8 female, 24 ± 8 yrs were randomly assigned into 2 training groups performing either 2 session per week of treadmill running or ergometer cycling in addition to 3 skating specific sessions (technique, plyometrics, parkour for 8 weeks. Training intensity was determined within non-specific (cycling or running and effects on specific endurance capacity within a specific incremental exercise test. Before and after the intervention all athletes performed a specific (300m and one non-specific (30s cycling or 200m running all-out sprint test according to the group affiliation. To determine the accumulation of blood lactate (BLa and glucose (BGL 20 μl arterialized blood was drawn at rest, as well as in 1 min intervals for 10 min after the sprint test. The sport-specific peak oxygen uptake (VO2 peak was significantly increased (+17%; p = 0.01 in both groups and highly correlated with the sprint performance (r = -0.71. BLa values decreased significantly (-18%, p = 0.02 after the specific sprint test from pre to post-testing without any group effect. However, BGL values only showed a significant decrease (-2%, p = 0.04 in the running group. The close relationship between aerobic capacity and sprint performance in inline speed skating highlights the positive effects of endurance training. Although both training programs were equally effective in improving endurance and sprint capacities, the metabolic results indicate a faster recovery after high intensity efforts for all athletes, as well as a higher reliance on the fat metabolism for athletes who trained in the running group.

  7. Polarized training has greater impact on key endurance variables than threshold, high intensity or high volume training

    Directory of Open Access Journals (Sweden)

    Thomas eStöggl

    2014-02-01

    Full Text Available Endurance athletes integrate four conditioning concepts in their training programs: high-volume training (HVT, ‘threshold-training’ (THR, high-intensity interval training (HIIT and a combination of these aforementioned concepts known as polarized training (POL. The purpose of this study was to explore which of these four training concepts provides the greatest response on key components of endurance performance in well-trained endurance athletes. Methods: Forty eight runners, cyclists, triathletes and cross-country skiers (peak oxygen uptake: (VO2peak: 62.6±7.1 mL∙min-1∙kg-1 were randomly assigned to one of four groups performing over nine weeks. An incremental test, work economy and a VO2peak tests were performed. Training intensity was heart rate controlled. Results: POL demonstrated the greatest increase in VO2peak (+6.8 ml∙min∙kg-1 or 11.7%, P0.05. Conclusion: POL resulted in the greatest improvements in most key variables of endurance performance in well-trained endurance athletes. THR or HVT did not lead to further improvements in performance related variables.

  8. mDurance: A Novel Mobile Health System to Support Trunk Endurance Assessment

    Directory of Open Access Journals (Sweden)

    Oresti Banos

    2015-06-01

    Full Text Available Low back pain is the most prevalent musculoskeletal condition. This disorder constitutes one of the most common causes of disability worldwide, and as a result, it has a severe socioeconomic impact. Endurance tests are normally considered in low back pain rehabilitation practice to assess the muscle status. However, traditional procedures to evaluate these tests suffer from practical limitations, which potentially lead to inaccurate diagnoses. The use of digital technologies is considered here to facilitate the task of the expert and to increase the reliability and interpretability of the endurance tests. This work presents mDurance, a novel mobile health system aimed at supporting specialists in the functional assessment of trunk endurance by using wearable and mobile devices. The system employs a wearable inertial sensor to track the patient trunk posture, while portable electromyography sensors are used to seamlessly measure the electrical activity produced by the trunk muscles. The information registered by the sensors is processed and managed by a mobile application that facilitates the expert’s normal routine, while reducing the impact of human errors and expediting the analysis of the test results. In order to show the potential of the mDurance system, a case study has been conducted. The results of this study prove the reliability of mDurance and further demonstrate that practitioners are certainly interested in the regular use of a system of this nature.

  9. Reproducibility of an aerobic endurance test for nonexpert swimmers

    OpenAIRE

    Veronese da Costa, Adalberto; Costa,Manoel da Cunha; Guerra,Luis Marcos de Medeiros; Barbosa,Tiago Manuel Cabral dos Santos; Carlos,Daniel Medeiros; Silva,Antônio José

    2012-01-01

    Adalberto Veronese da Costa,1,2 Manoel da Cunha Costa,3 Daniel Medeiros Carlos,1 Luis Marcos de Medeiros Guerra,1,2 Antônio José Silva,2 Tiago Manoel Cabral dos Santos Barbosa2,41Department of Physical Education, Bioscience Laboratory of Human Kinetics, Rio Grande do Norte State University, Mossoró, Brazil; 2Sport Sciences Trás-os-Montes e Alto Douro University, Research Center in Sport, Health and Human Development, Vila Real, Portugal; 3Superior Sc...

  10. Docosahexaenoic acid confers enduring neuroprotection in experimental stroke.

    Science.gov (United States)

    Hong, Sung-Ha; Belayev, Ludmila; Khoutorova, Larissa; Obenaus, Andre; Bazan, Nicolas G

    2014-03-15

    Recently we demonstrated that docosahexaenoic acid (DHA) is highly neuroprotective when animals were allowed to survive during one week. This study was conducted to establish whether the neuroprotection induced by DHA persists with chronic survival. Sprague-Dawley rats underwent 2h of middle cerebral artery occlusion (MCAo) and treated with DHA or saline at 3h after MCAo. Animals received neurobehavioral examination (composite neuroscore, rota-rod, beam walking and Y maze tests) followed by ex vivo magnetic resonance imaging and histopathology at 3 weeks. DHA improved composite neurologic score beginning on day 1 by 20%, which persisted throughout weeks 1-3 by 24-41% compared to the saline-treated group. DHA prolonged the latency in rota-rod on weeks 2-3 by 162-178%, enhanced balance performance in the beam walking test on weeks 1 and 2 by 42-51%, and decreased the number of entries in the Y maze test by 51% and spontaneous alteration by 53% on week 2 compared to the saline-treated group. DHA treatment reduced tissue loss (computed from T2-weighted images) by 24% and total and cortical infarct volumes by 46% and 54% compared to the saline-treated group. These results show that DHA confers enduring ischemic neuroprotection. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

  11. Calf Endurance and Achilles Tendon Structure in Classical Ballet Dancers.

    Science.gov (United States)

    Zellers, Jennifer A; van Ostrand, Katrina; Silbernagel, Karin Grävare

    2017-06-15

    Optimal lower leg function is critical for ballet dancers to meet their occupational requirements. Achilles tendon injury is particularly detrimental to ballet dancers. While standardized measures have been validated and incorporated into clinical practice for use in people with Achilles tendon injury, normative ranges specific to the dancer population have not been described. The purpose of this pilot study was to observe the performance of pre-professional ballet students and professional ballet dancers on a well-established test battery for lower leg functional performance as well as ultra-sonographic evaluation of the structure of their Achilles tendons. The dancers in this study had significantly shorter Achilles tendons than non-dancers (p = 0.016). Dancers demonstrated significantly higher maximum heel-rise height on the heel-rise test for calf endurance (p < 0.001) but performed significantly less work than non-dancers (p = 0.014). The results of this study support the use of the heel-rise test as a tool for screening and to guide rehabilitation.

  12. Endurance training increases the efficiency of rat skeletal muscle mitochondria.

    Science.gov (United States)

    Zoladz, Jerzy A; Koziel, Agnieszka; Woyda-Ploszczyca, Andrzej; Celichowski, Jan; Jarmuszkiewicz, Wieslawa

    2016-10-01

    Endurance training enhances mitochondrial oxidative capacity, but its effect on mitochondria functioning is poorly understood. In the present study, the influence of an 8-week endurance training on the bioenergetic functioning of rat skeletal muscle mitochondria under different assay temperatures (25, 35, and 42 °C) was investigated. The study was performed on 24 adult 4-month-old male Wistar rats, which were randomly assigned to either a treadmill training group (n = 12) or a sedentary control group (n = 12). In skeletal muscles, endurance training stimulated mitochondrial biogenesis and oxidative capacity. In isolated mitochondria, endurance training increased the phosphorylation rate and elevated levels of coenzyme Q. Moreover, a decrease in mitochondrial uncoupling, including uncoupling protein-mediated proton leak, was observed after training, which could explain the increased reactive oxygen species production (in nonphosphorylating mitochondria) and enhanced oxidative phosphorylation efficiency. At all studied temperatures, endurance training significantly augmented H2O2 production (and coenzyme Q reduction level) in nonphosphorylating mitochondria and decreased H2O2 production (and coenzyme Q reduction level) in phosphorylating mitochondria. Endurance training magnified the hyperthermia-induced increase in oxidative capacity and attenuated the hyperthermia-induced decline in oxidative phosphorylation efficiency and reactive oxygen species formation of nonphosphorylating mitochondria via proton leak enhancement. Thus, endurance training induces both quantitative and qualitative changes in muscle mitochondria that are important for cell signaling as well as for maintaining muscle energy homeostasis, especially at high temperatures.

  13. Muscular strength and endurance and cardio-metabolic health in disadvantaged Hispanic children from the U.S.

    Directory of Open Access Journals (Sweden)

    Ryan D. Burns

    2017-03-01

    Full Text Available The predictive relationship between muscular strength and endurance and cardio-metabolic health, independent from aerobic fitness, is not clear in disadvantaged Hispanic children. The purpose of this study was to examine the predictive relationship between muscular strength and endurance and clustered cardio-metabolic risk, controlling for aerobic fitness, in Hispanic children from low-income schools. Participants were 320 Hispanic children (Mean age = 10.1 ± 1.1 years; 164 girls, 156 boys recruited during the 2014–2015 and 2015–2016 academic years from five low-income schools from the state of Utah in the U.S. Muscular strength and endurance was assessed using the push-up and curl-up tests and estimated VO2 Peak was calculated from the Progressive Aerobic Cardiovascular Endurance Run. A clustered metabolic syndrome composite score (MetS was calculated from cardio-metabolic health measurements consisting of HDL cholesterol, triglycerides, waist circumference, blood glucose, and mean arterial pressure (MAP. Multi-level general linear mixed effects models were used to examine the predictive relationship between muscular strength and endurance and MetS, controlling for the effect of aerobic fitness and the clustering of children within classrooms and schools. Children who were in the middle and upper tertiles for muscular strength and endurance associated with a lower (more favorable MetS score (middle tertile: β = −2.59, 95% C.I. [−4.23, −0.95], p < 0.05; upper tertile: β = −1.57, 95% C.I. [−3.20, −0.16], p < 0.05. The results suggest that higher levels of muscular strength and endurance relate to lower cardio-metabolic risk, independent of aerobic fitness, in Hispanic children from low-income schools.

  14. Increased Blood Lactate Level Deteriorates Running Economy in World Class Endurance Athletes.

    Science.gov (United States)

    Hoff, Jan; Støren, Øyvind; Finstad, Arnstein; Wang, Eivind; Helgerud, Jan

    2016-05-01

    Blood lactate accumulation is associated with development of muscle fatigue and negatively correlated to endurance performance. No research has quantified the effects of lactate presence at moderate levels of lactate accumulation. The purpose of this study was to test whether 2 moderate blood lactate concentration levels affect running economy (RE) when running at the individual lactate threshold (LT). Seven male world class endurance athletes with an average V[Combining Dot Above]O2max of 80.7 ± 2.7 ml·kg·min or 5.8 ± 0.5 L·min participated in this study. After the V[Combining Dot Above]O2max test, the subjects were resting or walking and in a random order tested for RE at their LT velocity when the blood lactate level reached either 3 mmol·L or 5 mmol·L. After a new 5-minute exercising period at maximal aerobic velocity, the crossover lactate value RE testing was performed. Running economy was significantly (p ≤ 0.05) deteriorated from 0.668 ± 0.044 to 0.705 ± 0.056 ml·kg·m or 5.5% (p ≤ 0.05) for blood lactate level of 3 mmol·L compared with 5 mmol·L, respectively. Increased lactate level from 3 to 5 mmol·L is thus accompanied by deteriorated RE at LT running velocity. The deteriorated RE at moderate levels of lactate concentration emphasizes the importance of avoiding intensities above LT in the early parts of a dominantly aerobic endurance competition. It also emphasizes the importance of a high V[Combining Dot Above]O2max for aerobic endurance athletes and may partly explain the V[Combining Dot Above]O2 slow component as impaired RE.

  15. Respiratory muscle endurance is limited by lower ventilatory efficiency in post-myocardial infarction patients

    OpenAIRE

    Neves,Laura M. T.; Karsten,Marlus; Neves,Victor R.; Beltrame,Thomas; Borghi-Silva,Audrey; Catai,Aparecida M.

    2014-01-01

    Background: Reduced respiratory muscle endurance (RME) contributes to increased dyspnea upon exertion in patients with cardiovascular disease. Objective: The objective was to characterize ventilatory and metabolic responses during RME tests in post-myocardial infarction patients without respiratory muscle weakness. Method: Twenty-nine subjects were allocated into three groups: recent myocardial infarction group (RG, n=9), less-recent myocardial infarction group (LRG, n=10), and contr...

  16. Reliability and fatigue characteristics of a standing hip isometric endurance protocol.

    Science.gov (United States)

    Mutchler, Jessica A; Weinhandl, Joshua T; Hoch, Matthew C; Van Lunen, Bonnie L

    2015-08-01

    Muscle fatigue is a common consideration when evaluating and rehabilitating athletic injuries. The presence of muscular fatigue has been previously determined by quantifying median frequency (MF) through a power spectral analysis on EMG signals collected throughout an endurance task. Research has not yet determined if a prolonged isometric test in a standing position generates muscular fatigue of the hip. The purpose of this study was to determine the reliability and fatigue characteristics of a standing hip isometric endurance test. Twenty healthy participants completed one 60-s Maximum Voluntary Isometric Contraction of standing hip flexion, extension, adduction, and abduction. MF of the participants' dominant limb rectus femoris (RF), biceps femoris (BF), gluteus maximus (GMax), gluteus medius (GMed) and adductor longus (ADD) was determined via surface electromyography during two sessions, 30-min apart. Reliability values (ICC2,1) were moderate-to-excellent for all time intervals of each action (FlexionRF: >0.80; ExtensionBF: >0.89; ExtensionGMax: >0.60; AdductionADD: >0.78; AbductionGMed: >0.60) and MF significantly decreased over time for all actions. Results suggest the endurance test is a reliable technique to generate muscular fatigue for hip flexion, extension, adduction and abduction. It can be used as a time efficient fatigue protocol specific to the RF, BF, GMax, ADD and GMed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Enduring epigenetic landmarks define the cancer microenvironment

    Science.gov (United States)

    Pidsley, Ruth; Lawrence, Mitchell G.; Zotenko, Elena; Niranjan, Birunthi; Statham, Aaron; Song, Jenny; Chabanon, Roman M.; Qu, Wenjia; Wang, Hong; Richards, Michelle; Nair, Shalima S.; Armstrong, Nicola J.; Nim, Hieu T.; Papargiris, Melissa; Balanathan, Preetika; French, Hugh; Peters, Timothy; Norden, Sam; Ryan, Andrew; Pedersen, John; Kench, James; Daly, Roger J.; Horvath, Lisa G.; Stricker, Phillip; Frydenberg, Mark; Taylor, Renea A.; Stirzaker, Clare; Risbridger, Gail P.; Clark, Susan J.

    2018-01-01

    The growth and progression of solid tumors involves dynamic cross-talk between cancer epithelium and the surrounding microenvironment. To date, molecular profiling has largely been restricted to the epithelial component of tumors; therefore, features underpinning the persistent protumorigenic phenotype of the tumor microenvironment are unknown. Using whole-genome bisulfite sequencing, we show for the first time that cancer-associated fibroblasts (CAFs) from localized prostate cancer display remarkably distinct and enduring genome-wide changes in DNA methylation, significantly at enhancers and promoters, compared to nonmalignant prostate fibroblasts (NPFs). Differentially methylated regions associated with changes in gene expression have cancer-related functions and accurately distinguish CAFs from NPFs. Remarkably, a subset of changes is shared with prostate cancer epithelial cells, revealing the new concept of tumor-specific epigenome modifications in the tumor and its microenvironment. The distinct methylome of CAFs provides a novel epigenetic hallmark of the cancer microenvironment and promises new biomarkers to improve interpretation of diagnostic samples. PMID:29650553

  18. Effects of fluid, electrolyte and substrate ingestion on endurance capacity.

    Science.gov (United States)

    Maughan, R J; Fenn, C E; Leiper, J B

    1989-01-01

    The availability of carbohydrate (CHO) as a substrate for the exercising muscles is known to be a limiting factor in the performance of prolonged cycle exercise, and provision of exogenous CHO in the form of glucose can increase endurance capacity. The present study examined the effects of ingestion of fluids and of CHO in different forms on exercise performance. Six male volunteers exercised to exhaustion on a cycle ergometer at a workload which required approximately 70% of Vo2max. After one preliminary trial, subjects performed this exercise test on six occasions, one week apart. Immediately before exercise, and at 10-min intervals throughout, subjects ingested 100 ml of one of the following: control (no drink), water, glucose syrup, fructose syrup, glucose-fructose syrup or a dilute glucose-electrolyte solution. Each of the syrup solutions contained approximately 36 g CHO per 100 ml; the isotonic glucose-electrolyte solution contained 4 g glucose per 100 ml. A randomised Latin square order of administration of trials was employed. Expired air samples for determination of Vo2, respiratory exchange ratio and rate of CHO oxidation were collected at 15-min intervals. Venous blood samples were obtained before and after exercise. Subjects drinking the isotonic glucose-electrolyte solution exercised longer (90.8 (12.4) min, mean (SEM] than on the control test (70.2 (8.3) min; p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

  19. Metabolic Response to Four Weeks of Muscular Endurance Resistance Training

    Directory of Open Access Journals (Sweden)

    John W. Farrell III

    2017-10-01

    Full Text Available Background: Previous investigations have shown that muscular endurance resistance training (MERT is conducive in improving the onset of blood lactate accumulation (OBLA. However, the metabolic response and time course for adaption is still unclear. Objective: The aims of the current study were to evaluate and track the metabolic response to an individual session of MERT as well as to assess performance adaptations of supplementing an aerobic exercise training program with four weeks of MERT. Methods: Seventeen aerobically active men were randomly assigned to either the experimental (EX or control group (CON, 9 EX and 8 CON. Baseline measures included a graded exercise test (GXT and 1-repetition maximum (1RM testing for leg press (LP, leg curl (LC, and leg extension (LE. CON continued their regular aerobic activity while the EX supplemented their regular aerobic exercise with 4 weeks of MERT. Results: No significant group differences were observed for all pre-training variables. Following four weeks of training no significant differences in cardiorespiratory or metabolic variables were observed for either group. However, significant improvements in LC and LE 1-RM were observed in EX compared to CON. Substantial accumulations in blood lactate were observed following each MERT session. Conclusion: Four weeks of MERT did not improve cardiorespiratory or metabolic variables, but did significantly improve LC and LE. MERT was also observed to induce a blood lactate response similar to that of HIIT. These findings suggest greater than four weeks is need to see metabolic adaptations conducive for improved aerobic performance using MERT.

  20. Metabolic and exercise endurance effects of coffee and caffeine ingestion.

    Science.gov (United States)

    Graham, T E; Hibbert, E; Sathasivam, P

    1998-09-01

    Caffeine (Caf) ingestion increases plasma epinephrine (Epi) and exercise endurance; these results are frequently transferred to coffee (Cof) consumption. We examined the impact of ingestion of the same dose of Caf in Cof or in water. Nine healthy, fit, young adults performed five trials after ingesting (double blind) either a capsule (Caf or placebo) with water or Cof (decaffeinated Cof, decaffeinated with Caf added, or regular Cof). In all three Caf trials, the Caf dose was 4.45 mg/kg body wt and the volume of liquid was 7.15 ml/kg. After 1 h of rest, the subject ran at 85% of maximal O2 consumption until voluntary exhaustion (approximately 32 min in the placebo and decaffeinated Cof tests). In the three Caf trials, the plasma Caf and paraxanthine concentrations were very similar. After 1 h of rest, the plasma Epi was increased (P capsules than with Cof. During the exercise there were no differences in Epi among the three Caf trials, and the Epi values were all greater (P capsule trial; there were no differences among the other four tests. One cannot extrapolate the effects of Caf to Cof; there must be a component(s) of Cof that moderates the actions of Caf.

  1. Compliance in doing Senam Kesegaran Jasmani 1988 exercise improves cardiorespiratory endurance of attention deficit/hyperactivity disorder children

    Directory of Open Access Journals (Sweden)

    Listya T. Mirtha

    2018-05-01

    Full Text Available Background: Physical exercise was hypothesized to be able to improve the behavior of children with attention deficit/hyperactivity disorder (ADHD by improving attention and concentration. Several studies mentioned that physical exercise could make ADHD children calmer, not only as a supportive therapy, but also as a therapeutic therapy. The aim of this study was to evaluate the effects of physical exercise to the behavior of ADHD patients and to analyze the effects of Senam Kesegaran Jasmani 1988 (SKJ 88 exercise compliance to the cardiorespiratory endurance in ADHD children.Methods: This study was an experimental study with 40 subjects from a special needs school in Tangerang, Indonesia. Subjects were given SKJ 88 exercise for 8 weeks, and the level of cardiorespiratory endurance was assessed with 600 m run before and after intervention.Results: 21 subjects (52.5% were compliant, and the rest were very compliant. Although statistical analysis showed that there was no significant difference in cardiorespiratory endurance before and after intervention, the mean results of cardiorespiratory endurance test before intervention was higher than after. Mean time spent in the 600-m run before intervention was 497.9 seconds (SD 73.53, and after intervention was 313.7 seconds (SD 43.28.Conclusion: Based on the statistical test, we concluded that there was significant decrease of time spent for cardiorespiratory endurance test (p<0.001. The reduction of time taken to run 600 m by 184.3 seconds (SD 73.33 showed the improvement of cardiorespiratory endurance after the treatment.

  2. Non-conscious visual cues related to affect and action alter perception of effort and endurance performance

    Directory of Open Access Journals (Sweden)

    Anthony William Blanchfield

    2014-12-01

    Full Text Available The psychobiological model of endurance performance proposes that endurance performance is determined by a decision-making process based on perception of effort and potential motivation. Recent research has reported that effort-based decision-making during cognitive tasks can be altered by non-conscious visual cues relating to affect and action. The effect of these non-conscious visual cues on effort and performance during physical tasks is however unknown. We report two experiments investigating the effect of subliminal priming with visual cues related to affect and action on perception of effort and endurance performance. In Experiment 1 thirteen individuals were subliminally primed with happy or sad faces as they cycled to exhaustion in a counterbalanced and randomized crossover design. A paired t-test (happy vs. sad faces revealed that individuals cycled for significantly longer (178 s, p = .04 when subliminally primed with happy faces. A 2 x 5 (condition x iso-time ANOVA also revealed a significant main effect of condition on rating of perceived exertion (RPE during the time to exhaustion (TTE test with lower RPE when subjects were subliminally primed with happy faces (p = .04. In Experiment 2, a single-subject randomization tests design found that subliminal priming with action words facilitated a significantly longer (399 s, p = .04 TTE in comparison to inaction words (p = .04. Like Experiment 1, this greater TTE was accompanied by a significantly lower RPE (p = .03. These experiments are the first to show that subliminal visual cues relating to affect and action can alter perception of effort and endurance performance. Non-conscious visual cues may therefore influence the effort-based decision-making process that is proposed to determine endurance performance. Accordingly, the findings raise notable implications for individuals who may encounter such visual cues during endurance competitions, training, or health related exercise.

  3. Effect of thyme extract supplementation on lipid peroxidation, antioxidant capacity, PGC-1α content and endurance exercise performance in rats.

    Science.gov (United States)

    Khani, Mostafa; Motamedi, Pezhman; Dehkhoda, Mohammad Reza; Dabagh Nikukheslat, Saeed; Karimi, Pouran

    2017-01-01

    Athletes have a large extent of oxidant agent production. In the current study, we aimed to determine the influence of thyme extract on the endurance exercise performance, mitochondrial biogenesis, and antioxidant status in rats. Twenty male Wistar rats were randomly divided into two groups receiving either normal drinking water (non-supplemented group, n  = 10) or thyme extract, 400 mg/kg, (supplemented group, n  = 10). Rats in both groups were subjected to endurance treadmill training (27 m/min, 10% grade, 60 min, and 5 days/week for 8 weeks). Finally, to determine the endurance capacity, time to exhaustion treadmill running at 36 m/min speed was assessed. At the end of the endurance capacity test, serum and soleus muscle samples were collected and their superoxide dismutase (SOD) and glutathione peroxidase (GPx) activity, as well as malondialdehyde (MDA) concentration were measured. Protein expression of PGC-1α, as a marker of mitochondrial biogenesis, was also determined in the soleus muscle tissue by immunoblotting assay. Findings revealed that the exhaustive running time in the treatment group was significantly ( p  extract supplemented group (t 18  = 8.11, p  antioxidant capacity between groups. Furthermore, thyme supplementation significantly ( p  extract supplementation increased endurance exercise tolerance in intact animals, although decrease of oxidative stress and regulation of the PGC-1α protein expression are not considered as underlying molecular mechanisms.

  4. Endurance training and GH administration in elderly women

    DEFF Research Database (Denmark)

    Lange, K H; Lorentsen, J; Isaksson, F

    2001-01-01

    and after completion of the training program. Similarly, no effect on subcutaneous abdominal adipose tissue lipolysis was observed when combining endurance training with rhGH administration. However, in both the placebo and the GH groups, fat oxidation was significantly increased during exercise performed......In the present study, the effect of endurance training alone and endurance training combined with recombinant human growth hormone (rhGH) administration on subcutaneous abdominal adipose tissue lipolysis was investigated. Sixteen healthy women [age 75 +/- 2 yr (mean +/- SE)] underwent a 12-wk...... endurance training program on a cycle ergometer. rhGH was administered in a randomized, double-blinded, placebo-controlled design in addition to the training program. Subcutaneous abdominal adipose tissue lipolysis was estimated by means of microdialysis combined with measurements of subcutaneous abdominal...

  5. Bone health in endurance athletes: runners, cyclists, and swimmers.

    Science.gov (United States)

    Scofield, Kirk L; Hecht, Suzanne

    2012-01-01

    Weight-bearing exercise has been recognized widely to be beneficial for long-term bone health. However inherent differences in bone-loading characteristics and energy expenditure during participation in endurance sports place many endurance athletes at a relative disadvantage with regard to bone health compared with other athletes. Adolescents and adults who participate in endurance sports, such as running, and non-weight-bearing sports, such as biking and swimming, often have lower bone mineral density (BMD) than athletes participating in ball and power sports, and sometimes their BMD is lower than their inactive peers. Low BMD increases the risk of stress and fragility fractures, both while an athlete is actively competing and later in life. This article reviews the variable effects of distance running, cycling, swimming, and triathlons on bone health; the evaluation of stress and fragility fractures; and the diagnosis, management, and prevention of low BMD in endurance athletes.

  6. Effects of Cycling Versus Running Training on Sprint and Endurance Capacity in Inline Speed Skating

    Science.gov (United States)

    Stangier, Carolin; Abel, Thomas; Mierau, Julia; Hollmann, Wildor; Strüder, Heiko K.

    2016-01-01

    The purpose of this study was to compare the effects of running versus cycling training on sprint and endurance capacity in inline speed skating. Sixteen elite athletes (8 male, 8 female, 24 ± 8 yrs) were randomly assigned into 2 training groups performing either 2 session per week of treadmill running or ergometer cycling in addition to 3 skating specific sessions (technique, plyometrics, parkour) for 8 weeks. Training intensity was determined within non-specific (cycling or running) and effects on specific endurance capacity within a specific incremental exercise test. Before and after the intervention all athletes performed a specific (300m) and one non-specific (30s cycling or 200m running) all-out sprint test according to the group affiliation. To determine the accumulation of blood lactate (BLa) and glucose (BGL) 20 μl arterialized blood was drawn at rest, as well as in 1 min intervals for 10 min after the sprint test. The sport-specific peak oxygen uptake (VO2 peak) was significantly increased (+17%; p = 0.01) in both groups and highly correlated with the sprint performance (r = -0.71). BLa values decreased significantly (-18%, p = 0.02) after the specific sprint test from pre to post-testing without any group effect. However, BGL values only showed a significant decrease (-2%, p = 0.04) in the running group. The close relationship between aerobic capacity and sprint performance in inline speed skating highlights the positive effects of endurance training. Although both training programs were equally effective in improving endurance and sprint capacities, the metabolic results indicate a faster recovery after high intensity efforts for all athletes, as well as a higher reliance on the fat metabolism for athletes who trained in the running group. Key points In addition to a highly developed aerobic performance inline speed skaters also require a highly trained anaerobic capacity to be effective in the sprint sections such as the mass start, tactical attacks

  7. Altitude training for elite endurance performance: a 2012 update.

    Science.gov (United States)

    Fudge, Barry W; Pringle, Jamie S M; Maxwell, Neil S; Turner, Gareth; Ingham, Stephen A; Jones, Andrew M

    2012-01-01

    Altitude training is commonly used by endurance athletes and coaches in pursuit of enhancement of performance on return to sea level. The purpose of the current review article was to update and evaluate recent literature relevant to the practical application of altitude training for endurance athletes. Consequently, the literature can be considered in either of two categories: performance-led investigations or mechanistic advancements/insights. Each section discusses the relevant literature and proposes future directions where appropriate.

  8. Critical determinants of combined sprint and endurance performance: an integrative analysis from muscle fiber to the human body.

    Science.gov (United States)

    van der Zwaard, Stephan; van der Laarse, Willem J; Weide, Guido; Bloemers, Frank W; Hofmijster, Mathijs J; Levels, Koen; Noordhof, Dionne A; de Koning, Jos J; de Ruiter, Cornelis J; Jaspers, Richard T

    2018-04-01

    Optimizing physical performance is a major goal in current physiology. However, basic understanding of combining high sprint and endurance performance is currently lacking. This study identifies critical determinants of combined sprint and endurance performance using multiple regression analyses of physiologic determinants at different biologic levels. Cyclists, including 6 international sprint, 8 team pursuit, and 14 road cyclists, completed a Wingate test and 15-km time trial to obtain sprint and endurance performance results, respectively. Performance was normalized to lean body mass 2/3 to eliminate the influence of body size. Performance determinants were obtained from whole-body oxygen consumption, blood sampling, knee-extensor maximal force, muscle oxygenation, whole-muscle morphology, and muscle fiber histochemistry of musculus vastus lateralis. Normalized sprint performance was explained by percentage of fast-type fibers and muscle volume ( R 2 = 0.65; P body.

  9. Measuring Ucrit and endurance: equipment choice influences estimates of fish swimming performance.

    Science.gov (United States)

    Kern, P; Cramp, R L; Gordos, M A; Watson, J R; Franklin, C E

    2018-01-01

    This study compared the critical swimming speed (U crit ) and endurance performance of three Australian freshwater fish species in different swim-test apparatus. Estimates of U crit measured in a large recirculating flume were greater for all species compared with estimates from a smaller model of the same recirculating flume. Large differences were also observed for estimates of endurance swimming performance between these recirculating flumes and a free-surface swim tunnel. Differences in estimates of performance may be attributable to variation in flow conditions within different types of swim chambers. Variation in estimates of swimming performance between different types of flumes complicates the application of laboratory-based measures to the design of fish passage infrastructure. © 2017 The Fisheries Society of the British Isles.

  10. Nutrition for endurance sports: marathon, triathlon, and road cycling.

    Science.gov (United States)

    Jeukendrup, Asker E

    2011-01-01

    Endurance sports are increasing in popularity and athletes at all levels are looking for ways to optimize their performance by training and nutrition. For endurance exercise lasting 30 min or more, the most likely contributors to fatigue are dehydration and carbohydrate depletion, whereas gastrointestinal problems, hyperthermia, and hyponatraemia can reduce endurance exercise performance and are potentially health threatening, especially in longer events (>4 h). Although high muscle glycogen concentrations at the start may be beneficial for endurance exercise, this does not necessarily have to be achieved by the traditional supercompensation protocol. An individualized nutritional strategy can be developed that aims to deliver carbohydrate to the working muscle at a rate that is dependent on the absolute exercise intensity as well as the duration of the event. Endurance athletes should attempt to minimize dehydration and limit body mass losses through sweating to 2-3% of body mass. Gastrointestinal problems occur frequently, especially in long-distance races. Problems seem to be highly individual and perhaps genetically determined but may also be related to the intake of highly concentrated carbohydrate solutions, hyperosmotic drinks, as well as the intake of fibre, fat, and protein. Hyponatraemia has occasionally been reported, especially among slower competitors with very high intakes of water or other low sodium drinks. Here I provide a comprehensive overview of recent research findings and suggest several new guidelines for the endurance athlete on the basis of this. These guidelines are more detailed and allow a more individualized approach.

  11. Master athletes are extending the limits of human endurance

    Directory of Open Access Journals (Sweden)

    Romuald Lepers

    2016-12-01

    Full Text Available The increased participation of master athletes (i.e. > 40 years old in endurance and ultra-endurance events (> 6h duration over the past few decades has been accompanied by an improvement in their performances at a much faster rate than their younger counterparts. Ageing does however result in a decrease in overall endurance performance. Such age-related declines in performance depend upon the modes of locomotion, event duration and gender of the participant. For example, smaller age-related declines in cycling performance than in running and swimming have been documented. The relative stability of gender differences observed across the ages suggests that the age-related declines in physiological function did not differ between males and females. Among the main physiological determinants of endurance performance, the maximal oxygen consumption (VO2max appears to be the parameter that is most altered by age. Exercise economy and the exercise intensity at which a high fraction of VO2max can be sustained (i.e. lactate threshold, seem to decline to a lesser extent with advancing age. The ability to maintain a high exercise-training stimulus with advancing age is emerging as the single most important means of limiting the rate of decline in endurance performance. By constantly extending the limits of (ultra-endurance, master athletes therefore represent an important insight into the ability of humans to maintain physical performance and physiological function with advancing age.

  12. Specific descriptions of functional providing of the special endurance of boxers

    Directory of Open Access Journals (Sweden)

    S.B. Kiprich

    2015-03-01

    Full Text Available Purpose: to determine the specific characteristics of functional and metabolic support of special endurance of qualified boxers. Material: in research took part 16 boxers of high qualification at the age of 19-26 years. To estimate special endurance is used technique of detection the basic parameters of performance boxers "Spuderg-10." To estimate the response of cardiorespiratory system during the test "3x3" is used portable ergo-spirometry complex «Meta Max 3B» (Cortex, Germany. Results: It is shown that the range of individual distinctions of indexes of capacity and functional providing of the special endurance increased in every round under act of accumulation of fatigue. It is related to distinctions of kinetics of the cardiorespiratory system (by the increase of pulmonary ventilation in the first round, by the consumption of О 2 (by a capacity for the achievement of VO 2 max - in the second and by power of reaction of respiratory indemnification of metabolic acidosis - in the third. These distinctions are registered in default of reliable distinctions of quantitative descriptions of acidemic changes in an organism, increasing in the process of the test job processing. Conclusions: in different periods (rounds in boxers high grade found differences of manifestation and combinations of properties features of functional readiness.

  13. Comparative Review of Endurance Development in Cadets and Students in Track-and-Field Classes and Training at Educational Institutions of State Emergency Service of Ukraine

    Directory of Open Access Journals (Sweden)

    В. М. Жогло

    2016-08-01

    Full Text Available The purpose of the research is to provide a comparative review of the endurance development in cadets and students in track-and-field classes and training at educational institutions of the State Emergency Service of Ukraine. Research methods: analysis of scientific and methodological literature, pedagogical testing and methods of mathematical statistics of data reduction. Research results. The study resulted in a comparative analysis of the levels of endurance development in the cadets and the first-year students of the School of Psychology and the School of Emergency Rescue Forces of the National University of Civil Defence of Ukraine. Conclusions. The study results prove that the first-year students of the School of Psychology and the School of Emergency Rescue Forces have a low level of endurance (special and aerobic as compared to the cadets. In this regard, the physical training syllabus ought to include more exercises intended to develop special and aerobic endurance.

  14. 29 CFR 780.607 - “Primarily employed” in agriculture.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 3 2010-07-01 2010-07-01 false âPrimarily employedâ in agriculture. 780.607 Section 780... AGRICULTURE, PROCESSING OF AGRICULTURAL COMMODITIES, AND RELATED SUBJECTS UNDER THE FAIR LABOR STANDARDS ACT Employment in Agriculture and Livestock Auction Operations Under the Section 13(b)(13) Exemption Requirements...

  15. Effect of speed endurance training and reduced training volume on running economy and single muscle fiber adaptations in trained runners

    DEFF Research Database (Denmark)

    Skovgaard, Casper; Christiansen, Danny; Christensen, Peter Møller

    2018-01-01

    The aim of the present study was to examine whether improved running economy with a period of speed endurance training and reduced training volume could be related to adaptations in specific muscle fibers. Twenty trained male (n = 14) and female (n = 6) runners (maximum oxygen consumption (VO2 -m.......3 ± 0.3 vs. 18.9 ± 0.3 km/h) after than before the intervention. Thus, improved running economy with intense training may be related to changes in expression of proteins linked to energy consuming processes in primarily ST muscle fibers....

  16. RELATIONSHIPS BETWEEN MUSCLE FATIGUE CHARACTERISTICS AND MARKERS OF ENDURANCE PERFORMANCE

    Directory of Open Access Journals (Sweden)

    Martyn G. Morris

    2008-12-01

    Full Text Available The aim of this study was to examine the relationship of a range of in-vivo whole muscle characteristics to determinants of endurance performance. Eleven healthy males completed a cycle ergometer step test to exhaustion for the determination of the lactate threshold, gross mechanical efficiency, peak power and VO2max. On two separate occasions, contractile and fatigue characteristics of the quadriceps femoris were collected using a specially designed isometric strength-testing chair. Muscle fatigue was then assessed by stimulating the muscle for 3 minutes. Force, rate of force development and rates of relaxation were calculated at the beginning and end of the 3 minute protocol and examined for reliability and in relation to lactate threshold, VO2max, gross mechanical efficiency and peak power. Muscle characteristics, rate of force development and relaxation rate were demonstrated to be reliable measures. Force drop off over the 3 minutes (fatigue index was related to lactate threshold (r = -0.72 p < 0.01 but not to VO2max. The rate of force development related to the peak power at the end of the cycle ergometer test (r = -0.75 p < 0.01. Rates of relaxation did not relate to any of the performance markers. We found in-vivo whole muscle characteristics, such as the fatigue index and rate of force development, relate to specific markers of peripheral, but not to central, fitness components. Our investigation suggests that muscle characteristics assessed in this way is reliable and could be feasibly utilised to further our understanding of the peripheral factors underpinning performance

  17. Effects of Acute Endurance Exercise on Plasma Protein Profiles of Endurance-Trained and Untrained Individuals over Time

    Directory of Open Access Journals (Sweden)

    Marius Schild

    2016-01-01

    Full Text Available Acute physical exercise and repeated exercise stimuli affect whole-body metabolic and immunologic homeostasis. The aim of this study was to determine plasma protein profiles of trained (EET, n=19 and untrained (SED, n=17 individuals at rest and in response to an acute bout of endurance exercise. Participants completed a bicycle exercise test at an intensity corresponding to 80% of their VO2max. Plasma samples were taken before, directly after, and three hours after exercise and analyzed using multiplex immunoassays. Seventy-eight plasma variables were included in the final analysis. Twenty-nine variables displayed significant acute exercise effects in both groups. Seven proteins differed between groups, without being affected by acute exercise. Among these A2Macro and IL-5 were higher in EET individuals while leptin showed elevated levels in SED individuals. Fifteen variables revealed group and time differences with elevated levels for IL-3, IL-7, IL-10, and TNFR2 in EET individuals. An interaction effect could be observed for nine variables including IL-6, MMP-2, MMP-3, and muscle damage markers. The proteins that differ between groups indicate a long-term exercise effect on plasma protein concentrations. These findings might be of importance in the development of exercise-based strategies in the prevention and therapy of chronic metabolic and inflammatory diseases and for training monitoring.

  18. Breath holding endurance: stability over time and relationship with self-assessed persistence

    Directory of Open Access Journals (Sweden)

    Daisy G.Y. Thompson-Lake

    2017-09-01

    Full Text Available Breath holding (BH endurance has been suggested as a measure of the distress tolerance that could predict the outcome of attempts to implement behavior changes, such as stopping smoking or illicit substance use. It is not known however, to what degree BH endurance is a variable trait that may vary depending on situational context, or a stable state characteristic. We measured BH in two groups of participants at baseline and 22 and 89 days (N = 62 and N = 41 post-baseline and in a third group at multiple times points across a 5-week period (N = 44. Participants also filled out a questionnaire created to assess their perceived persistence compared to peers. Correlations were found between baseline and final BH measures (r’s > 0.67, p’s < 0.0001 at all time points. When groups were combined, regardless of time point, Spearman’s rank correlation showed a strong positive correlation (rs = 0.66, p < 0.0001. Self-assessed persistence was not related to BH endurance. This study provides evidence of the stability of BH across time when tested under the same conditions in young adults. Further research is needed to clarify whether BH is linked to behavioral outcomes.

  19. Effects of Laminaria japonica polysaccharides on exercise endurance and oxidative stress in forced swimming mouse model.

    Science.gov (United States)

    Yan, Feiwei; Hao, Haitao

    2016-12-01

    Polysaccharides are the major active ingredients responsible for the bioactivities of Laminaria japonica. However, the effects of L. japonica polysaccharides (LJP) on exercise endurance and oxidative stress have never been investigated. Therefore, this study was conducted to investigate the effects of LJP on exercise endurance and oxidative stress in a forced swimming mouse model. The animals were divided into four groups, namely the control (C), LJP-75, LJP-150, and LJP-300 groups, which received physiological saline and 75, 150, and 300 mg kg(-1) LJP, respectively, by gavage once a day for 28 days. This was followed by a forced swimming test and measurements of various biochemical parameters. LJP increased swimming time to exhaustion, the liver and muscle glycogen content, and levels of superoxide dismutase, glutathione peroxidase, and catalase in the serum, liver, and muscle, which were accompanied by corresponding decreases in the malondialdehyde (MDA) content of the same tissues. Furthermore, decreases in blood lactic acid and serum myeloperoxidase (MPO) levels were observed. LJP enhanced exercise endurance and protected mice against exhaustive exercise-induced oxidative stress.

  20. Peripheral fatigue limits endurance exercise via a sensory feedback-mediated reduction in spinal motoneuronal output.

    Science.gov (United States)

    Amann, Markus; Venturelli, Massimo; Ives, Stephen J; McDaniel, John; Layec, Gwenael; Rossman, Matthew J; Richardson, Russell S

    2013-08-01

    This study sought to determine whether afferent feedback associated with peripheral muscle fatigue inhibits central motor drive (CMD) and thereby limits endurance exercise performance. On two separate days, eight men performed constant-load, single-leg knee extensor exercise to exhaustion (85% of peak power) with each leg (Leg1 and Leg2). On another day, the performance test was repeated with one leg (Leg1) and consecutively (within 10 s) with the other/contralateral leg (Leg2-post). Exercise-induced quadriceps fatigue was assessed by reductions in potentiated quadriceps twitch-force from pre- to postexercise (ΔQtw,pot) in response to supramaximal magnetic femoral nerve stimulation. The output from spinal motoneurons, estimated from quadriceps electromyography (iEMG), was used to reflect changes in CMD. Rating of perceived exertion (RPE) was recorded during exercise. Time to exhaustion (∼9.3 min) and exercise-induced ΔQtw,pot (∼51%) were similar in Leg1 and Leg2 (P > 0.5). In the consecutive leg trial, endurance performance of the first leg was similar to that observed during the initial trial (∼9.3 min; P = 0.8); however, time to exhaustion of the consecutively exercising contralateral leg (Leg2-post) was shorter than the initial Leg2 trial (4.7 ± 0.6 vs. 9.2 ± 0.4 min; P fatigue and associated afferent feedback limits the development of peripheral fatigue and compromises endurance exercise performance by inhibiting CMD.

  1. Spin-trappers and vitamin E prolong endurance to muscle fatigue in mice

    Energy Technology Data Exchange (ETDEWEB)

    Novelli, G.P.; Bracciotti, G.; Falsini, S. (Univ. of Florence (Italy))

    1990-01-01

    The involvement of free radicals in endurance to muscle effort is suggested by experimental and clinical data. Therefore, experiments have been performed to observe the effect of trapping free radicals on endurance to swimming in mice. Animals were injected intraperitoneally with each of three spin-trappers (N-tert-Butyl-alpha-Phenyl-Nitrone (PBN),alpha-4-Pyridyil-1-Oxide-N-tert-Butyl-Nitrone (POBN) and 5,5-Dimethyl-1-Pirrolyn-N-Oxide (DMPO): 0.2 ml of 10(-1) molar solution). Each mouse was submitted to a swimming test to control resistance to exhaustion (a) without any treatment, (b) after administration of each spin-trapper in a random order (c) after saline. Control experiments were performed with saline and with vitamin E. Endurance to swimming was greatly prolonged by pretreatment with all the spin-trappers (DMPO less than 0.0001; POBN less than 0.0001; PBN less than 0.001) and with Vitamin E. Experiments state that compared to treatment with spin-trappers or Vitamin E, administration of saline alone did not enhance time to exhaustion so that the increase in time to exhaustion with the various free radical scavengers was not the effect of training. Therefore, free radicals could be considered as one of the factors terminating muscle effort in mice.

  2. Increased trunk extension endurance is associated with meaningful improvement in balance among older adults with mobility problems.

    Science.gov (United States)

    Suri, Pradeep; Kiely, Dan K; Leveille, Suzanne G; Frontera, Walter R; Bean, Jonathan F

    2011-07-01

    To determine whether trunk extension endurance changes with training are associated with clinically meaningful improvements in balance among mobility-limited older adults. Longitudinal data from a randomized controlled trial. Outpatient rehabilitation research center. Community-dwelling older adults (N=64; mean age, 75.9y) with mobility limitations as defined by a score of 4 to 10 on the Short Physical Performance Battery. Sixteen weeks of progressive resistance training. Outcomes were the Berg Balance Scale (BBS) and the Unipedal Stance Time (UST). Predictors included leg strength, leg power, trunk extension endurance, and the product of heart rate and blood pressure (RPP) at the final stage of an exercise tolerance test. We performed an analysis of data from participants who completed 16 weeks of training by using binary outcomes defined by a clinically meaningful change (CMC) from baseline to completion of the intervention (BBS=4 units; UST=5s). The association of predictor variables with balance outcomes was examined separately and together in multivariate adjusted logistic regression models. Trunk extension endurance in seconds (1.04 [1.00-1.09]) was independently associated with CMC on the BBS. Trunk extension endurance (1.02 [1.00-1.03]) was independently associated with CMC on the UST. Other physical attributes were not associated with meaningful change in balance. Improvements in trunk extension endurance were independently associated with CMCs in balance in older adults. Leg strength, leg power, and RPP were not associated with CMC in balance. Poor trunk extension endurance may be a rehabilitative impairment worthy of further study as a modifiable factor linked to balance among older adults. Copyright © 2011 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  3. Arctigenin enhances swimming endurance of sedentary rats partially by regulation of antioxidant pathways.

    Science.gov (United States)

    Wu, Ruo-ming; Sun, Yan-yan; Zhou, Ting-ting; Zhu, Zhi-yuan; Zhuang, Jing-jing; Tang, Xuan; Chen, Jing; Hu, Li-hong; Shen, Xu

    2014-10-01

    Arctigenin, a phenylpropanoid dibenzylbutyrolactone lignan found in traditional Chinese herbs, has been determined to exhibit a variety of pharmacological activities, including anti-tumor, anti-inflammation, neuroprotection, and endurance enhancement. In the present study, we investigated the antioxidation and anti-fatigue effects of arctigenin in rats. Rat L6 skeletal muscle cell line was exposed to H2O2 (700 μmol/L), and ROS level was assayed using DCFH-DA as a probe. Male SD rats were injected with arctigenin (15 mg·kg(-1)·d(-1), ip) for 6 weeks, and then the weight-loaded forced swimming test (WFST) was performed to evaluate their endurance. The levels of antioxidant-related genes in L6 cells and the skeletal muscles of rats were analyzed using real-time RT-PCR and Western blotting. Incubation of L6 cells with arctigenin (1, 5, 20 μmol/L) dose-dependently decreased the H2O2-induced ROS production. WFST results demonstrated that chronic administration of arctigenin significantly enhanced the endurance of rats. Furthermore, molecular biology studies on L6 cells and skeletal muscles of the rats showed that arctigenin effectively increased the expression of the antioxidant-related genes, including superoxide dismutase (SOD), glutathione reductase (Gsr), glutathione peroxidase (GPX1), thioredoxin (Txn) and uncoupling protein 2 (UCP2), through regulation of two potential antioxidant pathways: AMPK/PGC-1α/PPARα in mitochondria and AMPK/p53/Nrf2 in the cell nucleus. Arctigenin efficiently enhances rat swimming endurance by elevation of the antioxidant capacity of the skeletal muscles, which has thereby highlighted the potential of this natural product as an antioxidant in the treatment of fatigue and related diseases.

  4. Arctigenin enhances swimming endurance of sedentary rats partially by regulation of antioxidant pathways

    Science.gov (United States)

    Wu, Ruo-ming; Sun, Yan-yan; Zhou, Ting-ting; Zhu, Zhi-yuan; Zhuang, Jing-jing; Tang, Xuan; Chen, Jing; Hu, Li-hong; Shen, Xu

    2014-01-01

    Aim: Arctigenin, a phenylpropanoid dibenzylbutyrolactone lignan found in traditional Chinese herbs, has been determined to exhibit a variety of pharmacological activities, including anti-tumor, anti-inflammation, neuroprotection, and endurance enhancement. In the present study, we investigated the antioxidation and anti-fatigue effects of arctigenin in rats. Methods: Rat L6 skeletal muscle cell line was exposed to H2O2 (700 μmol/L), and ROS level was assayed using DCFH-DA as a probe. Male SD rats were injected with arctigenin (15 mg·kg−1·d−1, ip) for 6 weeks, and then the weight-loaded forced swimming test (WFST) was performed to evaluate their endurance. The levels of antioxidant-related genes in L6 cells and the skeletal muscles of rats were analyzed using real-time RT-PCR and Western blotting. Results: Incubation of L6 cells with arctigenin (1, 5, 20 μmol/L) dose-dependently decreased the H2O2-induced ROS production. WFST results demonstrated that chronic administration of arctigenin significantly enhanced the endurance of rats. Furthermore, molecular biology studies on L6 cells and skeletal muscles of the rats showed that arctigenin effectively increased the expression of the antioxidant-related genes, including superoxide dismutase (SOD), glutathione reductase (Gsr), glutathione peroxidase (GPX1), thioredoxin (Txn) and uncoupling protein 2 (UCP2), through regulation of two potential antioxidant pathways: AMPK/PGC-1α/PPARα in mitochondria and AMPK/p53/Nrf2 in the cell nucleus. Conclusion: Arctigenin efficiently enhances rat swimming endurance by elevation of the antioxidant capacity of the skeletal muscles, which has thereby highlighted the potential of this natural product as an antioxidant in the treatment of fatigue and related diseases. PMID:25152028

  5. Effects of acute supplementation of Panax ginseng on endurance running in a hot & humid environment

    Science.gov (United States)

    Ping, Fadzel Wong Chee; Keong, Chen Chee; Bandyopadhyay, Amit

    2011-01-01

    Background & objectives: Athletes in Malaysia need to perform in a hot and humid environment due to the climatic nature of the country. c0 hronic supplementation of Panax ginseng (PG) (a deciduous perennial plant belonging to the Araliaceae family) enhances physical performance. As the ergogenic effect of acute supplementation of PG on endurance performance has not been explored in the Malaysian population especially in a hot and humid condition this study was taken up. Methods: Nine heat adapted recreational runners (age : 25.4 ± 6.9 yr, body mass : 57.6 ± 8.4 kg; body height : 168.3 ± 7.6 cm) were recruited in this placebo-controlled double-blind randomized study. Subjects ingested 200 mg of PG one hour before the exercise test on treadmill at 70 per cent of their VO2max in a laboratory environment of 31 °C and 70 per cent relative humidity. They drank 3 ml/kg body weight of cool water every 20 min during the exercise to prevent adverse effects of dehydration. Blood samples were drawn every 20 min for the analysis of glucose, lactate, insulin and free fatty acids. Oxygen uptake was determined every 20 min while heart rate, body and skin temperatures, and ratings of perceived exertion (RPE) were recorded every 10 min during the trials. Results: Endurance running time to exhaustion did not differ between PG and placebo trials. Heart rate, skin temperature, core body temperature, oxygen uptake, RPE, plasma insulin, glucose, free fatty acid and lactate levels during the endurance exercise did not show any significant differences between the trials. Interpretation & conclusions: We conclude that acute supplementation of 200 mg of PG did not affect the endurance running performance of the heat-adapted male recreational runners in the heat. PMID:21321426

  6. Respiratory muscle endurance is limited by lower ventilatory efficiency in post-myocardial infarction patients

    Directory of Open Access Journals (Sweden)

    Laura M. T. Neves

    2014-03-01

    Full Text Available Background: Reduced respiratory muscle endurance (RME contributes to increased dyspnea upon exertion in patients with cardiovascular disease. Objective: The objective was to characterize ventilatory and metabolic responses during RME tests in post-myocardial infarction patients without respiratory muscle weakness. Method: Twenty-nine subjects were allocated into three groups: recent myocardial infarction group (RG, n=9, less-recent myocardial infarction group (LRG, n=10, and control group (CG, n=10. They underwent two RME tests (incremental and constant pressure with ventilatory and metabolic analyses. One-way ANOVA and repeated measures one-way ANOVA, both with Tukey post-hoc, were used between groups and within subjects, respectively. Results: Patients from the RG and LRG presented lower metabolic equivalent and ventilatory efficiency than the CG on the second (50± 06, 50± 5 vs. 42± 4 and third part (50± 11, 51± 10 vs. 43± 3 of the constant pressure RME test and lower metabolic equivalent during the incremental pressure RME test. Additionally, at the peak of the incremental RME test, RG patients had lower oxygen uptake than the CG. Conclusions : Post-myocardial infarction patients present lower ventilatory efficiency during respiratory muscle endurance tests, which appears to explain their inferior performance in these tests even in the presence of lower pressure overload and lower metabolic equivalent.

  7. Effect of endurance training on dental erosion, caries, and saliva.

    Science.gov (United States)

    Frese, C; Frese, F; Kuhlmann, S; Saure, D; Reljic, D; Staehle, H J; Wolff, D

    2015-06-01

    The aim of this investigation was to give insights into the impact of endurance training on oral health, with regard to tooth erosion, caries, and salivary parameters. The study included 35 triathletes and 35 non-exercising controls. The clinical investigation comprised oral examination, assessment of oral status with special regard to caries and erosion, saliva testing during inactivity, and a self-administered questionnaire about eating, drinking, and oral hygiene behavior. In addition, athletes were asked about their training habits and intake of beverages and sports nutrition. For saliva assessment during exercise, a subsample of n = 15 athletes volunteered in an incremental running field test (IRFT). Athletes showed an increased risk for dental erosion (P = 0.001). No differences were observed with regard to caries prevalence and salivary parameters measured during inactivity between athletes and controls. Among athletes, a significant correlation was found between caries prevalence and the cumulative weekly training time (r = 0.347, P = 0.04). In athletes after IRFT and at maximum workload, saliva flow rates decreased (P = 0.001 stimulated; P = 0.01 unstimulated) and saliva pH increased significantly (P = 0.003). Higher risk for dental erosions, exercise-dependent caries risk, and load-dependent changes in saliva parameters point out the need for risk-adapted preventive dental concepts in the field of sports dentistry. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. β-alanine supplementation improves isometric endurance of the knee extensor muscles

    Directory of Open Access Journals (Sweden)

    Sale Craig

    2012-06-01

    Full Text Available Abstract Background We examined the effect of four weeks of β-alanine supplementation on isometric endurance of the knee extensors at 45% maximal voluntary isometric contraction (MVIC. Methods Thirteen males (age 23 ± 6 y; height 1.80 ± 0.05 m; body mass 81.0 ± 10.5 kg, matched for pre-supplementation isometric endurance, were allocated to either a placebo (n = 6 or β-alanine (n = 7; 6.4 g·d-1 over 4 weeks supplementation group. Participants completed an isometric knee extension test (IKET to fatigue, at an intensity of 45% MVIC, before and after supplementation. In addition, two habituation tests were completed in the week prior to the pre-supplementation test and a further practice test was completed in the week prior to the post-supplementation test. MVIC force, IKET hold-time, and impulse generated were recorded. Results IKET hold-time increased by 9.7 ± 9.4 s (13.2% and impulse by 3.7 ± 1.3 kN·s-1 (13.9% following β-alanine supplementation. These changes were significantly greater than those in the placebo group (IKET: t(11 = 2.9, p ≤0.05; impulse: t(11 = 3.1, p ≤ 0.05. There were no significant changes in MVIC force in either group. Conclusion Four weeks of β-alanine supplementation at 6.4 g·d-1 improved endurance capacity of the knee extensors at 45% MVIC, which most likely results from improved pH regulation within the muscle cell as a result of elevated muscle carnosine levels.

  9. Hydrogen peroxide production is not primarily increased in human myotubes established from type 2 diabetic subjects.

    Science.gov (United States)

    Minet, A D; Gaster, M

    2011-09-01

    Increased oxidative stress and mitochondrial dysfunction have been implicated in the development of insulin resistance in type 2 diabetes. To date, it is unknown whether increased mitochondrial reactive oxygen species (ROS) production in skeletal muscle from patients with type 2 diabetes is primarily increased or a secondary adaptation to environmental, lifestyle, and hormonal factors. This study investigates whether ROS production is primarily increased in isolated diabetic myotubes. Mitochondrial membrane potential, hydrogen peroxide (H(2)O(2)), superoxide, and mitochondrial mass were determined in human myotubes precultured under normophysiological conditions. Furthermore, the corresponding ATP synthesis was measured in isolated mitochondria. Muscle biopsies were taken from 10 lean subjects, 10 obese subjects, and 10 subjects with type 2 diabetes; satellite cells were isolated, cultured, and differentiated to myotubes. Mitochondrial mass, membrane potential/mitochondrial mass, and superoxide-production/mitochondrial mass were not different between groups. In contrast, H(2)O(2) production/mitochondrial mass and ATP production were significantly reduced in diabetic myotubes compared to lean controls (P production is not primarily increased in diabetic myotubes but rather is reduced. Moreover, the comparable ATP/H(2)O(2) ratios indicate that the reduced ROS production in diabetic myotubes parallels the reduced ATP production because ROS production in diabetic myotubes must be considered to be in a proportion comparable to lean. Thus, the increased ROS production seen in skeletal muscle of type 2 diabetic patients is an adaptation to the in vivo conditions.

  10. Endurance training enhances BDNF release from the human brain

    DEFF Research Database (Denmark)

    Seifert, Thomas; Brassard, Patrice; Wissenberg, Mads

    2010-01-01

    The circulating level of brain-derived neurotrophic factor (BDNF) is reduced in patients with major depression and type-2 diabetes. Because acute exercise increases BDNF production in the hippocampus and cerebral cortex, we hypothesized that endurance training would enhance the release of BDNF from...... the human brain as detected from arterial and internal jugular venous blood samples. In a randomized controlled study, 12 healthy sedentary males carried out 3 mo of endurance training (n = 7) or served as controls (n = 5). Before and after the intervention, blood samples were obtained at rest and during...... exercise. At baseline, the training group (58 + or - 106 ng x 100 g(-1) x min(-1), means + or - SD) and the control group (12 + or - 17 ng x 100 g(-1) x min(-1)) had a similar release of BDNF from the brain at rest. Three months of endurance training enhanced the resting release of BDNF to 206 + or - 108...

  11. Adaptations to speed endurance training in highly trained soccer players

    DEFF Research Database (Denmark)

    Nyberg, Michael Permin; Fiorenza, Matteo; Lund, Anders

    2016-01-01

    PURPOSE: The present study examined whether a period of additional speed endurance training would improve intense intermittent exercise performance in highly trained soccer players during the season and whether the training changed aerobic metabolism and the level of oxidative enzymes in type I...... and II muscle fibers. METHODS: During the last nine weeks of the season, thirteen semi-professional soccer players performed additional speed endurance training sessions consisting of 2-3 sets of 8 - 10 repetitions of 30 m sprints with 10 s of passive recovery (SET). Before and after SET, subjects...... in type I and II fibers did not change. CONCLUSION: In highly trained soccer players, additional speed endurance training is associated with an improved ability to perform repeated high-intensity work. To what extent the training-induced changes in V˙O2 kinetics and mechanical efficiency in type I fibers...

  12. Endurance time method for Seismic analysis and design of structures

    International Nuclear Information System (INIS)

    Estekanchi, H.E.; Vafai, A.; Sadeghazar, M.

    2004-01-01

    In this paper, a new method for performance based earthquake analysis and design has been introduced. In this method, the structure is subjected to accelerograms that impose increasing dynamic demand on the structure with time. Specified damage indexes are monitored up to the collapse level or other performance limit that defines the endurance limit point for the structure. Also, a method for generating standard intensifying accelerograms has been described. Three accelerograms have been generated using this method. Furthermore, the concept of Endurance Time has been described by applying these accelerograms to single and multi degree of freedom linear systems. The application of this method for analysis of complex nonlinear systems has been explained. Endurance Time method provides a uniform approach to seismic analysis and design of complex structures that can be applied in numerical and experimental investigations

  13. Effects of endurance and endurance-strength exercise on biochemical parameters of liver function in women with abdominal obesity.

    Science.gov (United States)

    Skrypnik, Damian; Ratajczak, Marzena; Karolkiewicz, Joanna; Mądry, Edyta; Pupek-Musialik, Danuta; Hansdorfer-Korzon, Rita; Walkowiak, Jarosław; Jakubowski, Hieronim; Bogdański, Paweł

    2016-05-01

    Obesity is a risk factor of nonalcoholic fatty liver disease. Although the standard therapy for obesity involves physical exercise, well-planned studies of the changes in liver function in response to different exercise intensities in obese subjects are scarce. The aim of the present study was to examine a question of how does exercise mode affect the liver function. 44 women with abdominal obesity were randomized into two exercise groups: endurance (group A) and endurance-strength (group B). Women in each group exercised for 60min 3 times/week for a 3-month period. Markers of liver function: serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyltranspeptidase (GGT), alkaline phosphatase (ALP) activities, and bilirubin levels were quantified. We found significant differences in ALT (pexercise. Blood ALT and AST tended to decrease in group B, increase in group A. Significant reduction in serum GGT level after exercise in both groups was observed (pexercise led to changes in serum ALP activity and total or direct bilirubin level. However, endurance-strength training resulted in significant decreases in serum indirect bilirubin (pexercise (group B). The mode of exercise does matter: endurance-strength exercise led to a greater improvement, compared to endurance exercise, in the liver function in women with abdominal obesity. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  14. Eningiomas: outcome, and analysis of prognostic factors of primarily resected tumors

    International Nuclear Information System (INIS)

    Stafford, S.L.; Perry, A.; Suman, V.; Meyer, B.; Scheithauer, B.W.; Shaw, E.G.; Earle, J.D.

    1996-01-01

    Purpose: 582 consecutive cases of primary intracranial meningioma undergoing resection at the Mayo Clinic, (Rochester, MN) were reviewed to determine overall survival (OS), progression free survival(PFS), prognostic factors predicting recurrence, and to determine the importance of radiation therapy in the management of this tumor. Materials and Methods: Between 1978-1988, 582 cases of primarily resected meningiomas were identified based on the tumor and operative registries where diagnosis was between 1978-1988 inclusive. PFS was identified by radiographic progression. Follow-up was accomplished by chart review, and a detailed questionnaire sent to patients and referring physicians. Estimation of OS and PFS distributions were done by the Kaplan-Meier method. The log rank test was used to assess which factors were associated with PFS. Proportional hazard modeling was performed to obtain a subset of independent predictors of PFS. Results: the median age was 57(5-93). 67% were female. CT identified the tumor in 91% of cases. There was associated edema in 21% and 2% were radiographically en plaque. There were 17 patients with multiple tumors, four of whom had a known diagnosis of neurofibromatosis. Gross total resection (GTR) was accomplished in 80%, radical subtotal or subtotal resection(STR) in 20%, and biopsy in 53) cellularity, and four or more mitoses per 10 HPF. Multivariate analysis indicated young age, male sex, en plaque at surgery, were significant for decreased PFS when only patient characteristics were considered. When treatment and pathologic factors were also considered, then young age, male sex, less than GTR, and tumor sheeting were predictors for decreased PFS. 10 patients had RT after initial resection, two of whom recurred. There were 107 first recurrences. 50 were observed(no intervention within 3 months), 35 treated by surgery alone, 11 had S+RT, and 11 were treated with RT alone. Considering those patients treated at recurrence (n=57), PFS was at

  15. Alternatives to the Six-Minute Walk Test in Pulmonary Arterial Hypertension

    OpenAIRE

    Mainguy, Vincent; Malenfant, Simon; Neyron, Anne-Sophie; Saey, Didier; Maltais, François; Bonnet, Sébastien; Provencher, Steeve

    2014-01-01

    INTRODUCTION: The physiological response during the endurance shuttle walk test (ESWT), the cycle endurance test (CET) and the incremental shuttle walk test (ISWT) remains unknown in PAH. We tested the hypothesis that endurance tests induce a near-maximal physiological demand comparable to incremental tests. We also hypothesized that differences in respiratory response during exercise would be related to the characteristics of the exercise tests. METHODS: Within two weeks, twenty-one PAH pati...

  16. Consumo de aminoácidos de cadeia ramificada não afeta o desempenho de endurance Branched-chain amino acids ingestion does not affect endurance performance

    Directory of Open Access Journals (Sweden)

    Marco Carlos Uchida

    2008-02-01

    Full Text Available A suplementação com aminoácidos de cadeia ramificada (BCAA é uma das manipulações dietéticas mais populares entre atletas engajados em atividades de endurance. Entretanto, o papel ergogênico destes aminoácidos ainda não está totalmente estabelecido. Portanto, o objetivo do presente trabalho foi avaliar o efeito do consumo de BCAA sobre o exercício de endurance realizado até a exaustão. A fim de provocar redução do estoque de glicogênio muscular e, por conseguinte, maximizar a utilização dos BCAA, os sujeitos (n=17 foram submetidos a uma sessão prévia de exercício (corrida realizada a 75% do VO2max por 40 min seguida por 2 tiros a 90% do VO2max por 10 min cada um. Subseqüentemente, após o consumo aleatório de BCAA (77 mg.kg-1 ou placebo, seguindo modelo duplo cego cruzado, os participantes executaram um teste para determinação da capacidade de endurance (corrida a 90% do Limiar anaeróbio até a exaustão. Ambos os experimentos, BCAA e placebo, foram separados por uma semana. Com relação ao tempo até a exaustão e a distância percorrida, nenhuma diferença foi detectada entre as condições experimentais. (Placebo: 50,1±8,9 vs BCAA: 52,4±4,5 min, respectivamente (Placebo: 8,8±1,3 vs BCAA: 9,1±0,6 km, respectivamente. Além disto, também não foi evidenciada diferença na concentração plasmática de glicose, de lactato e de amônia entre ambas condições experimentais. Em conclusão, a suplementação de BCAA não afetou o desempenho de endurance em um teste de corrida até a exaustão.Branched-chain amino acids (BCAA supplementation is one of the most popular dietary manipulations used by endurance athletes. However, the ergogenic role of these amino acids in endurance exercise is not well established yet. Therefore, the aim of this study was to evaluate the effect of BCAA supplementation upon endurance exercise performed until exhaustion. In order to induce glycogen supply reduction, and thus maximize BCAA

  17. Mixed maximal and explosive strength training in recreational endurance runners.

    Science.gov (United States)

    Taipale, Ritva S; Mikkola, Jussi; Salo, Tiina; Hokka, Laura; Vesterinen, Ville; Kraemer, William J; Nummela, Ari; Häkkinen, Keijo

    2014-03-01

    Supervised periodized mixed maximal and explosive strength training added to endurance training in recreational endurance runners was examined during an 8-week intervention preceded by an 8-week preparatory strength training period. Thirty-four subjects (21-45 years) were divided into experimental groups: men (M, n = 9), women (W, n = 9), and control groups: men (MC, n = 7), women (WC, n = 9). The experimental groups performed mixed maximal and explosive exercises, whereas control subjects performed circuit training with body weight. Endurance training included running at an intensity below lactate threshold. Strength, power, endurance performance characteristics, and hormones were monitored throughout the study. Significance was set at p ≤ 0.05. Increases were observed in both experimental groups that were more systematic than in the control groups in explosive strength (12 and 13% in men and women, respectively), muscle activation, maximal strength (6 and 13%), and peak running speed (14.9 ± 1.2 to 15.6 ± 1.2 and 12.9 ± 0.9 to 13.5 ± 0.8 km Ł h). The control groups showed significant improvements in maximal and explosive strength, but Speak increased only in MC. Submaximal running characteristics (blood lactate and heart rate) improved in all groups. Serum hormones fluctuated significantly in men (testosterone) and in women (thyroid stimulating hormone) but returned to baseline by the end of the study. Mixed strength training combined with endurance training may be more effective than circuit training in recreational endurance runners to benefit overall fitness that may be important for other adaptive processes and larger training loads associated with, e.g., marathon training.

  18. Can endurance training improve physical capacity and quality of life in young Fontan patients?

    Science.gov (United States)

    Hedlund, Eva R; Lundell, Bo; Söderström, Liselott; Sjöberg, Gunnar

    2018-03-01

    Children after Fontan palliation have reduced exercise capacity and quality of life. Our aim was to study whether endurance training could improve physical capacity and quality of life in Fontan patients. Fontan patients (n=30) and healthy age- and gender-matched control subjects (n=25) performed a 6-minute walk test at submaximal capacity and a maximal cycle ergometer test. Quality of life was assessed with Pediatric Quality of Life Inventory Version 4.0 questionnaires for children and parents. All tests were repeated after a 12-week endurance training programme and after 1 year. Patients had decreased submaximal and maximal exercise capacity (maximal oxygen uptake 35.0±5.1 ml/minute per·kg versus 43.7±8.4 ml/minute·per·kg, pquality of life score (70.9±9.9 versus 85.7±8.0, pimproved their submaximal exercise capacity in a 6-minute walk test (from 590.7±65.5 m to 611.8±70.9 m, pquality of life (pimprove maximal exercise capacity. At follow-up, submaximal exercise capacity had increased further and improved quality of life was sustained. The controls improved their maximal exercise capacity (pquality of life after training. At follow-up, improvement of maximal exercise capacity was sustained. We believe that an individualised endurance training programme for Fontan patients improves submaximal exercise capacity and quality of life in Fontan patients and the effect on quality of life appears to be long-lasting.

  19. Glucose ingestion during endurance training does not alter adaptation

    DEFF Research Database (Denmark)

    Åkerström, Thorbjörn; Fischer, Christian P; Plomgaard, Peter

    2009-01-01

    , 2) lower citrate synthase (CS) and beta-hydroxyacyl-CoA dehydrogenase (beta-HAD) activity and glycogen content in skeletal muscle, and 3) attenuated endurance performance enhancement in the trained state. To investigate this we studied nine male subjects who performed 10 wk of one-legged knee...... extensor training. They trained one leg while ingesting a 6% glucose solution (Glc) and ingested a sweetened placebo while training the other leg (Plc). The subjects trained their respective legs 2 h at a time on alternate days 5 days a week. Endurance training increased peak power (P(max)) and time...

  20. Effects of Three Commercially Available Sports Drinks on Substrate Metabolism and Subsequent Endurance Performance in a Postprandial State.

    Science.gov (United States)

    Qin, Lu; Wang, Qi-Rong; Fang, Zi-Long; Wang, Ting; Yu, Ai-Qi; Zhou, Yu-Jie; Zheng, Yi; Yi, Mu-Qing

    2017-04-12

    Purpose: To examine the effects of commercially available sports beverages with various components on substrate metabolism and subsequent performance. Methods: Two studies were conducted in a double-blinded, counterbalanced manner. Study I was designed to determine the glycemic index, while study II determined the utilization of substrates and subsequent exercise performance. Ten healthy male participants (age 21.70 ± 2.41 years, height 176.60 ± 5.23 cm, weight 66.58 ± 5.38 kg, V̇O 2max 48.1 ± 8.4 mL/kg/min) participated in both study I and study II. Three types of commercially available sports beverage powders were used. The powders consisted primarily of oligosaccharides (low molecular weight carbohydrates, L-CHO), hydrolyzed starch (high molecular weight CHO, H-CHO), and whey protein powder with carbohydrate (CHO-PRO). They were dissolved in purified water with identical CHO concentration of 8% ( w / v ). In study I, each participant underwent two oral glucose tolerance tests (OGTT) and one glycemic response test for each sports drink. In study II, participants cycled for 60 min at 70% V̇O 2max , one hour after consuming a standardized breakfast. One of four prescribed beverages (L-CHO, H-CHO, CHO-PRO, and Placebo control, PLA) was served at 0, 15, 30, 45 min during the exercise. Six hours after the first exercise session, participants came back for a "time to exhaustion test" (TTE). Blood samples were drawn at 0, 30, and 60 min in the first exercise session, while arterial blood gas analysis was conducted at 0, 30, and 60 min in both sessions. Subjective feelings (rating of perceived exertion and abdominal discomfort) were also evaluated every 30 min during exercise. Results: Compared to the reference standardized glucose solution, the glycemic index of the L-CHO beverage was 117.70 ± 14.25, while H-CHO was 105.50 ± 12.82, and CHO-PRO was 67.23 ± 5.88. During the exercise test, the insulin level at 30 and 60 min was significantly lower than baseline

  1. Energy Balance of Triathletes during an Ultra-Endurance Event

    Directory of Open Access Journals (Sweden)

    Anna Barrero

    2014-12-01

    Full Text Available The nutritional strategy during an ultra-endurance triathlon (UET is one of the main concerns of athletes competing in such events. The purpose of this study is to provide a proper characterization of the energy and fluid intake during real competition in male triathletes during a complete UET and to estimate the energy expenditure (EE and the fluid balance through the race. Methods: Eleven triathletes performed a UET. All food and drinks ingested during the race were weighed and recorded in order to assess the energy intake (EI during the race. The EE was estimated from heart rate (HR recordings during the race, using the individual HR-oxygen uptake (Vo2 regressions developed from three incremental tests on the 50-m swimming pool, cycle ergometer, and running treadmill. Additionally, body mass (BM, total body water (TBW and intracellular (ICW and extracellular water (ECW were assessed before and after the race using a multifrequency bioimpedance device (BIA. Results: Mean competition time and HR was 755 ± 69 min and 137 ± 6 beats/min, respectively. Mean EI was 3643 ± 1219 kcal and the estimated EE was 11,009 ± 664 kcal. Consequently, athletes showed an energy deficit of 7365 ± 1286 kcal (66.9% ± 11.7%. BM decreased significantly after the race and significant losses of TBW were found. Such losses were more related to a reduction of extracellular fluids than intracellular fluids. Conclusions: Our results confirm the high energy demands of UET races, which are not compensated by nutrient and fluid intake, resulting in a large energy deficit.

  2. Energy balance of triathletes during an ultra-endurance event.

    Science.gov (United States)

    Barrero, Anna; Erola, Pau; Bescós, Raúl

    2014-12-31

    The nutritional strategy during an ultra-endurance triathlon (UET) is one of the main concerns of athletes competing in such events. The purpose of this study is to provide a proper characterization of the energy and fluid intake during real competition in male triathletes during a complete UET and to estimate the energy expenditure (EE) and the fluid balance through the race. Eleven triathletes performed a UET. All food and drinks ingested during the race were weighed and recorded in order to assess the energy intake (EI) during the race. The EE was estimated from heart rate (HR) recordings during the race, using the individual HR-oxygen uptake (Vo2) regressions developed from three incremental tests on the 50-m swimming pool, cycle ergometer, and running treadmill. Additionally, body mass (BM), total body water (TBW) and intracellular (ICW) and extracellular water (ECW) were assessed before and after the race using a multifrequency bioimpedance device (BIA). Mean competition time and HR was 755 ± 69 min and 137 ± 6 beats/min, respectively. Mean EI was 3643 ± 1219 kcal and the estimated EE was 11,009 ± 664 kcal. Consequently, athletes showed an energy deficit of 7365 ± 1286 kcal (66.9% ± 11.7%). BM decreased significantly after the race and significant losses of TBW were found. Such losses were more related to a reduction of extracellular fluids than intracellular fluids. Our results confirm the high energy demands of UET races, which are not compensated by nutrient and fluid intake, resulting in a large energy deficit.

  3. Triacylglycerol Accumulation is not primarily affected in Myotubes established from Type 2 Diabetic Subjects

    DEFF Research Database (Denmark)

    Gaster, Michael; Beck-Nielsen, Henning

    2006-01-01

    In the present study, we investigated triacylglycerol (TAG) accumulation, glucose and fatty acid (FA) uptake, and glycogen synthesis (GS) in human myotubes from healthy, lean, and obese subjects with and without type 2 diabetes (T2D), exposed to increasing palmitate (PA) and oleate (OA...... uptake (P0.05). These results indicate that (1) TAG accumulation is not primarily affected in skeletal muscle tissue of obese and T2D; (2) induced inhibition of oxidative phosphorylation is followed by TAG accumulation...... in skeletal muscle of obese and T2D subjects is adaptive....

  4. Effects of caloric restriction and overnight fasting on cycling endurance performance.

    Science.gov (United States)

    Ferguson, Lisa M; Rossi, Kelly A; Ward, Emily; Jadwin, Emily; Miller, Todd A; Miller, Wayne C

    2009-03-01

    In addition to aerobic endurance and anaerobic capacity, high power-to-weight ratio (PWR) is important for cycling performance. Cyclists often try to lose weight before race season to improve body composition and optimize PWR. Research has demonstrated body fat-reducing benefits of exercise after fasting overnight. We hypothesized that fasted-state exercise in calorie-restricted trained cyclists would not result in performance decrements and that their PWR would improve significantly. We also hypothesized that substrate use during fasted-state submaximal endurance cycling would shift to greater reliance on fat. Ten trained, competitive cyclists completed a protocol consisting of baseline testing, 3 weeks of caloric restriction (CR), and post-CR testing. The testing sessions measured pre- and post-CR values for resting metabolic rate (RMR), body composition, VO2, PWR and power-to-lean weight ratio (PLWR), and power output, as well as 2-hour submaximal cycling performance, rating of perceived exertion (RPE), and respiratory exchange ratio (RER). There were no significant differences between baseline and post-CR for submaximal trial RER, power output, VO2, RMR, VO2max, or workload at VO2max. However, RPE was significantly lower, and PWR was significantly higher post-CR, whereas RER did not change. The cyclists' PWR and body composition improved significantly, and their overall weight, fat weight, and body fat percentage decreased. Lean mass was maintained. The cyclists' RPE decreased significantly during 2 hours of submaximal cycling post-CR, and there was no decrement in submaximal or maximal cycling performance after 3 weeks of CR combined with overnight fasting. Caloric restriction (up to 40% for 3 weeks) and exercising after fasting overnight can improve a cyclist's PWR without compromising endurance cycling performance.

  5. Aging well: Processing speed inhibition and working memory related to balance and aerobic endurance.

    Science.gov (United States)

    Zettel-Watson, Laura; Suen, Meagan; Wehbe, Lara; Rutledge, Dana N; Cherry, Barbara J

    2017-01-01

    The present study explored whether certain physical performance measures could be linked to specific cognitive domains in healthy older adults. A total of 50 adults (mean age 69.5 years, SD 8.1) were evaluated on physical performance using measures of balance (Fullerton Advanced Balance Scale), functional mobility (8-ft up-and-go), lower body strength (30-s chair stand), gait (30-ft walk velocity) and aerobic endurance (6-min walk). Cognitive measures included Stroop Color-Word Test, Digit Span Backward, Trail Making Tests, Everyday Problems Test, Digit Symbol Substitution and a Brown-Peterson test. Principal component analyses reduced cognition to domains of processing speed, inhibition and working memory. Hierarchical regression analyses were carried out with age and each physical measure as potential predictors of the three cognitive domains. The balance scale and 6-min walk were specifically associated with processing speed, inhibition and working memory. Better dynamic balance and aerobic endurance predicted enhanced processing speed, inhibition and working memory in older adults, with these last two domains considered components of executive function. Geriatr Gerontol Int 2017; 17: 108-115. © 2015 Japan Geriatrics Society.

  6. Lamin A/C mutation affecting primarily the right side of the heart

    Directory of Open Access Journals (Sweden)

    Laura Ollila

    2013-04-01

    Full Text Available LMNA mutations are amongst the most important causes of familial dilated cardiomyopathy. The most important cause of arrhythmogenic right ventricular cardiomyopathy (ARVC is desmosomal pathology. The aim of the study was to elucidate the role of LMNA mutations among Finnish cardiomyopathy patients. We screened 135 unrelated cardiomyopathy patients for LMNA mutations. Because of unusual phenotype, two patients were screened for the known Finnish ARVC-related mutations of desmosomal genes, and their Plakophilin-2b gene was sequenced. Myocardial samples from two patients were examined by immunohistochemical plakoglobin staining and in one case by electron microscopy. We found a new LMNA mutation Phe237Ser in a family of five affected members with a cardiomyopathy affecting primarily the right side of the heart. The phenotype resembles ARVC but does not fulfill the Task Force Criteria. The main clinical manifestations of the mutation were severe tricuspid insufficiency, right ventricular enlargement and failure. Three of the affected patients died of the heart disease, and the two living patients received heart transplants at ages 44 and 47. Electron microscopy showed nuclear blebbing compatible with laminopathy. Immunohisto - chemical analysis did not suggest desmosomal pathology. No desmosomal mutations were found. The Phe237Ser LMNA mutation causes a phenotype different from traditional cardiolaminopathy. Our findings suggest that cardiomyopathy affecting primarily the right side of the heart is not always caused by desmosomal pathology. Our observations highlight the challenges in classifying cardiomyopathies, as there often is significant overlap between the traditional categories.

  7. Correlating Multimodal Physical Sensor Information with Biological Analysis in Ultra Endurance Cycling

    Directory of Open Access Journals (Sweden)

    Giles D.Warrington

    2010-07-01

    Full Text Available The sporting domain has traditionally been used as a testing ground for new technologies which subsequently make their way into the public domain. This includes sensors. In this article a range of physical and biological sensors deployed in a 64 hour ultra-endurance non-stop cycling race are described. A novel algorithm to estimate the energy expenditure while cycling and resting during the event are outlined. Initial analysis in this noisy domain of “sensors in the field” are very encouraging and represent a first with respect to cycling.

  8. Does Attitude toward the Ad Endure? The Moderating Effects of Attention and Delay.

    OpenAIRE

    Chattopadhyay, Amitava; Nedungadi, Prakash

    1992-01-01

    Do the effects of attitude toward the ad on consumer decisions endure beyond the scenarios that characterize previous research? In examining this question, the authors focus on the persistence of ad-attitude effects as a function of the level of attention at encoding and the delay between ad exposure and response. The results of an experiment designed to test their hypotheses suggest that ad-attitude effects do not persist in a number of instances. Over time, as memory for an ad fades, its ef...

  9. Excellent endurance of MWCNT anode in micro-sized Microbial Fuel Cell

    KAUST Repository

    Mink, Justine E.; Hussain, Muhammad Mustafa

    2012-01-01

    Microbial Fuel Cells (MFCs) are a sustainable technology for energy production using bioelectrochemical reactions from bacteria. Microfabrication of micro-sized MFCs allows rapid and precise production of devices that can be integrated into Lab-on-a-chip or other ultra low power devices. We show a multi-walled carbon nanotubes (MWCNTs) integrated anode in a biocompatible and high power and current producing device. Long term testing of the MWCNT anode also reveals a high endurance and durable anode material that can be adapted as a long-lasting power source. © 2012 IEEE.

  10. Excellent endurance of MWCNT anode in micro-sized Microbial Fuel Cell

    KAUST Repository

    Mink, Justine E.

    2012-08-01

    Microbial Fuel Cells (MFCs) are a sustainable technology for energy production using bioelectrochemical reactions from bacteria. Microfabrication of micro-sized MFCs allows rapid and precise production of devices that can be integrated into Lab-on-a-chip or other ultra low power devices. We show a multi-walled carbon nanotubes (MWCNTs) integrated anode in a biocompatible and high power and current producing device. Long term testing of the MWCNT anode also reveals a high endurance and durable anode material that can be adapted as a long-lasting power source. © 2012 IEEE.

  11. Merlin C. Wittrock's Enduring Contributions to the Science of Learning

    Science.gov (United States)

    Mayer, Richard E.

    2010-01-01

    Among his many accomplishments in educational psychology, Merlin C. Wittrock is perhaps best remembered for his enduring contributions to the science of learning. His vision of how learning works is best explicated in articles published in "Educational Psychologist" (Wittrock, 1974, 1978, 1989, 1991, 1992), beginning with his classic 1974 article,…

  12. Molecular responses to moderate endurance exercise in skeletal muscle

    Science.gov (United States)

    This study examined alterations in skeletal-muscle growth and atrophy-related molecular events after a single bout of moderate-intensity endurance exercise. Muscle biopsies were obtained from 10 men (23 +/- 1 yr, body mass 80 +/- 2 kg, and VO(2peak) 45 +/- 1 ml x kg'¹ x min'¹) immediately (0 hr) and...

  13. Physiological benefits of a prolonged moderate intensity endurance ...

    African Journals Online (AJOL)

    Objectives. To assess the physiological changes that take place in patients with coronary artery disease after 6 and 18 months of moderate-intensity endurance training. Design. Prospective non-randomised controlled study. Setting. Joharmesburg Cardiac Rehabilitation Centre, a community-based phase ill cardiac ...

  14. Interval endurance capacity of talented youth soccer players

    NARCIS (Netherlands)

    Visscher, C; Elferink-Gemser, MT; Lemmink, KAPM

    The purpose of this study, in which 113 talented Youth soccer players (M = 16.0 yr., SD = 15), selected by their age and level of performance participated, was to investigate interval endurance capacity needed to play at the highest level of competition in the age-category 12 through 18.

  15. Non-allergic activation of eosinophils after strenuous endurance ...

    African Journals Online (AJOL)

    Objective. To determine the effect of prolonged endurance exercise on the serum concentrations of eosinophil cationic protein (ECP), immunoglobulin E (IgE) and upper respiratory tract symptoms (URTS). Design. In 11 healthy, experienced volunteers (6 males, 5 females, age 43 ± 9.8 years) the serum concentrations of ...

  16. Endurance and age : evidence from long-distance running data

    NARCIS (Netherlands)

    Sterken, Elmer

    2001-01-01

    This paper analyzes the impact of aging on long-run endurance. We analyze the determinants of running speed on distances from 5K to the marathon. We model running speed as a function of distance, age, and sex. We find evidence for interaction between age and sex, but not between distance and sex.

  17. Increasing Endurance by Building Fluency: Precision Teaching Attention Span.

    Science.gov (United States)

    Binder, Carl; And Others

    1990-01-01

    Precision teaching techniques can be used to chart students' attention span or endurance. Individual differences in attention span can then be better understood and dealt with effectively. The effects of performance duration on performance level, on error rates, and on learning rates are discussed. Implications for classroom practice are noted.…

  18. Effects of moderate and heavy endurance exercise on nocturnal HRV.

    Science.gov (United States)

    Hynynen, E; Vesterinen, V; Rusko, H; Nummela, A

    2010-06-01

    This study examined the effects of endurance exercise on nocturnal autonomic modulation. Nocturnal R-R intervals were collected after a rest day, after a moderate endurance exercise and after a marathon run in ten healthy, physically active men. Heart rate variability (HRV) was analyzed as a continuous four-hour period starting 30 min after going to bed for sleep. In relation to average nocturnal heart rate after rest day, increases to 109+/-6% and 130+/-11% of baseline were found after moderate endurance exercise and marathon, respectively. Standard deviation of R-R intervals decreased to 90+/-9% and 64+/-10%, root-mean-square of differences between adjacent R-R intervals to 87+/-10% and 55+/-16%, and high frequency power to 77+/-19% and 34+/-19% of baseline after moderate endurance exercise and marathon, respectively. Also nocturnal low frequency power decreased to 56+/-26% of baseline after the marathon. Changes in nocturnal heart rate and HRV suggest prolonged dose-response effects on autonomic modulation after exercises, which may give useful information on the extent of exercise-induced nocturnal autonomic modulation and disturbance to the homeostasis.

  19. Life prediction methods for the combined creep-fatigue endurance

    International Nuclear Information System (INIS)

    Wareing, J.; Lloyd, G.J.

    1980-09-01

    The basis and current status of development of the various approaches to the prediction of the combined creep-fatigue endurance are reviewed. It is concluded that an inadequate materials data base makes it difficult to draw sensible conclusions about the prediction capabilities of each of the available methods. Correlation with data for stainless steel 304 and 316 is presented. (U.K.)

  20. Solution-Space Screening of a Hypersonic Endurance Demonstrator

    Science.gov (United States)

    Chudoba, Bernd; Coleman, Gary; Oza, Amit; Gonzalez, Lex; Czysz, Paul

    2012-01-01

    This report documents a parametric sizing study performed to develop a program strategy for research and development and procurement of a feasible next-generation hypersonic air-breathing endurance demonstrator. Overall project focus has been on complementing technical and managerial decision-making during the earliest conceptual design phase towards minimization of operational, technical, and managerial risks.

  1. RESISTIVE EXERCISES IN THE DEVELOPMENT OF MUSCULAR STRENGTH AND ENDURANCE.

    Science.gov (United States)

    BURNHAM, STAN; MCCRAW, LYNN W.

    A STUDY WAS CONCERNED WITH A COMPARISON OF ISOTONIC, ISOMETRIC, AND SPEED EXERCISE PROGRAMS AS A MEANS OF DEVELOPING MUSCLE STRENGTH, ENDURANCE, SPEED, AND POWER. SUBJECTS FOR THE INVESTIGATION WERE 93 FRESHMEN AND SOPHOMORE MEN ENROLLED IN A PHYSICAL EDUCATION CLASS. AFTER MEASUREMENT OF INITIAL STATUS IN THE ATTRIBUTES UNDER CONSIDERATION, THE…

  2. Behind Closed Doors: Listening to the Voices of Women enduring ...

    African Journals Online (AJOL)

    Statistics reveal that there are large numbers of women, including those in marital unions or partnerships, who are enduring violence and abuse. Most of this abuse is at the hands of intimate partners and loved ones. The present study sought to develop insight into the reasons why Vha-Venda women in Thohoyandou ...

  3. NSAID and other analgesic use by endurance runners during ...

    African Journals Online (AJOL)

    Background. An increasing popularity of ultra-endurance events coupled with excessive or inappropriate non-steroidal anti-inflammatory drug (NSAID) use during such events could pose considerable potential risks to runners' health. Objective. To evaluate the incidence of NSAID and other analgesic use in distance ...

  4. Hydrotherapy added to endurance training versus endurance training alone in elderly patients with chronic heart failure: a randomized pilot study.

    Science.gov (United States)

    Caminiti, Giuseppe; Volterrani, Maurizio; Marazzi, Giuseppe; Cerrito, Anna; Massaro, Rosalba; Sposato, Barbara; Arisi, Arianna; Rosano, Giuseppe

    2011-04-14

    To assess if Hydrotherapy (HT) added to endurance training (ET) is more effective than ET alone in order to improve exercise tolerance of elderly male patients with chronic heart failure (CHF). Twenty-one male CHF patients, age 68+/-7 (mean+/-DS) years; ejection fraction 32+/-9. NYHA II-III were enrolled. Eleven pts were randomized to combined training (CT) group performing HT+ET and 10 patients to ET group (ET only). At baseline and after 24 weeks all patients underwent: 6-minute walking test (6MWT), assessment of quadriceps maximal voluntary contraction (MVC) and peak torque (PT), blood pressure and heart rate (HR), echocardiography and non-invasive hemodynamic evaluation. HT was performed 3 times/week in upright position at up to the xyphoid process at a temperature of 31°C. ET was performed 3 times/week. Exercise was well tolerated. No patients had adverse events. Distance at 6MWT improved in both groups (CT group: 150+/-32 m; ET group:105+/-28 m) with significant intergroup differences (p 0.001). On land diastolic BP and HR significantly decreased in the CT group while remained unchanged in the ET group (-11 mmHg+/-2, p 0.04; e - 12 bpm, p 0.03; respectively) CO and SV had a relative despite no significant increase in CT group TPR on land significantly decreased in CT group (-23+/-3 mmHg/l/m; p 0.01) while remained unchanged in ET group. Patients of CT group had no significant higher increase of both MVC and PT than ET group. CT training, significantly improves exercise tolerance and hemodynamic profile of patients with CHF. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

  5. Differences in muscle mechanical properties between elite power and endurance athletes: a comparative study.

    Science.gov (United States)

    Loturco, Irineu; Gil, Saulo; Laurino, Cristiano Frota de Souza; Roschel, Hamilton; Kobal, Ronaldo; Cal Abad, Cesar C; Nakamura, Fabio Y

    2015-06-01

    performance. The power group presented better performance in vertical jumps, supporting the validity of these tests to distinguish between endurance and power athletes. Furthermore, TMG can discriminate the "athlete-type" using noninvasive indices moderately correlated with explosive lower-body performance. In summary, both vertical jump and TMG assessments could be useful in identifying and selecting young athletes.

  6. Ventilatory muscle endurance training in quadriplegia: effects on breathing pattern.

    Science.gov (United States)

    Loveridge, B; Badour, M; Dubo, H

    1989-10-01

    We examined the effects of ventilatory muscle endurance training on resting breathing pattern in 12 C6-C7 traumatic quadriplegics at least 1 year post-injury. All subjects had complete motor loss below the lesion level. Subjects were randomly assigned to a training (N = 6), or a control group (N = 6). Baseline tests included measurement of resting ventilation and breathing pattern using mercury in rubber strain gauges for 20 minutes in a seated position; maximum inspiratory mouth pressure (MIP) at FRC, and sustainable inspiratory mouth pressure for 10 minutes (SIP); lung volumes, and arterial blood gases (ABG's). The training protocol consisted of breathing through an inspiratory resistor equivalent to 85% SIP for 15 minutes twice daily, 5 days a week for 8 weeks. Both trainers and controls attended the lab every 2 weeks for reassessment of MIP and SIP and the inspiratory resistance was increased in the training group as SIP increased. At the end of 8 weeks, baseline tests were repeated. All subjects had normal ABG's. There was a significant increase in mean MIP and SIP in both the control group (30% +/- 19% and 31% +/- 18% respectively), and in the training group (42% +/- 24% and 78% +/- 49% respectively). Although the absolute values for both MIP and SIP were greater in the training group than in the control group, the differences were not significant. The alterations in resting breathing pattern were also the same in both groups. Mean frequency decreased significantly in the control group (20.2/minute to 16.9/minute) and, while insignificant, the change in frequency in the training group was the same, 19.4/minute to 16.4/minute. Mean tidal volume (Vt) increased 18.2% of baseline Vt in the control group and 17.0% baseline in the trainers, resulting in no change in minute ventilation. As MIP and SIP increased similarly in both groups, the data from the control and trainers was pooled and timing changes re-evaluated pre- and post-study. A significant decrease in

  7. The Effect of Acute Endurance Exercise on Plasma Myostastin in Healthy Elderly Men

    Directory of Open Access Journals (Sweden)

    Meysam Gholamali

    2015-04-01

    Conclusion Plasma Myostatin decreased significantly in the response to endurance exercise, in healthy elderly men. Presumably, according to the results of this study, prescription of endurance exercise may decrease Myostatin and subsequently sarcopenia in elderly people.

  8. Effect of glucose infusion on endurance performance after beta-adrenoceptor blocker administration

    NARCIS (Netherlands)

    van Baak, M.A.; Mooij, J.M.

    1994-01-01

    Effect of glucose infusion on endurance performance after beta-adrenoceptor blocker administration. Van Baak MA, Mooij JM. Department of Human Biology, University of Limburg, Maastricht, The Netherlands. To investigate the effect of glucose (Glc) infusion on endurance performance after

  9. 77 FR 7243 - Proposed Information Collection (Operation Enduring Freedom/Operation Iraqi Freedom Veterans...

    Science.gov (United States)

    2012-02-10

    ... DEPARTMENT OF VETERANS AFFAIRS [OMB Control No. 2900-0728] Proposed Information Collection (Operation Enduring Freedom/ Operation Iraqi Freedom Veterans Health Needs Assessment) Activities Under OMB....'' SUPPLEMENTARY INFORMATION: Title: Operation Enduring Freedom/Operation Iraqi Freedom Veterans Health Needs...

  10. Gender, Sexual Orientation, and Rape Myth Acceptance: Preliminary Findings From a Sample of Primarily LGBQ-Identified Survey Respondents.

    Science.gov (United States)

    Schulze, Corina; Koon-Magnin, Sarah

    2017-02-01

    This study is among the first to examine the relationship between sexual orientation and rape myth adherence using a nationwide survey of primarily lesbian, gay, bisexual, and queer (LGBQ) respondents (n = 184). The more established Illinois Rape Myth Acceptance Scale and a modified Male Rape Survey serve as the primary instruments to test both rape myth adherence and instrument-appropriateness. Results suggest that respondents were most likely to support myths that discredit sexual assault allegations or excuse rape as a biological imperative and least likely to support myths related to physical resistance. Consistent with previous work, men exhibited higher levels of rape myth adherence than women. Regarding sexual orientation, respondents who identified as queer consistently exhibited lower levels of rape myth adherence than respondents who identified as gay.

  11. High-intensity lower limb endurance training in chronic respiratory disease

    OpenAIRE

    Tanaka, Takako; Arizono, Shinichi; Hanada, Masatoshi; Senjyu, Hideaki

    2015-01-01

    High-intensity endurance training is mainly undertaken during pulmonary rehabilitation for patients with chronic respiratory disease. High-intensity endurance training is recommended in many clinical management guidelines. High-intensity endurance training involves training generally at an intensity of at 60-80% of the patient’s peak work capacity or higher. The effects of high-intensity lower limb endurance training have mostly been investigated in chronic obstructive pulmonary disease (COPD...

  12. Cooling During Exercise: An Overlooked Strategy for Enhancing Endurance Performance in the Heat.

    Science.gov (United States)

    Stevens, Christopher J; Taylor, Lee; Dascombe, Ben J

    2017-05-01

    It is well established that endurance performance is negatively affected by environmental heat stress due to a complex interaction of physical, physiological and psychological alterations. Numerous scientific investigations have attempted to improve performance in the heat with pre-cooling (cooling prior to an exercise test), and as such this has become a well-established ergogenic practice for endurance athletes. However, the use of mid-cooling (cooling during an exercise test) has received considerably less research attention in comparison, despite recent evidence to suggest that the advantage gained from mid-cooling may outweigh that of pre-cooling. A range of mid-cooling strategies are beneficial for endurance performance in the heat, including the ingestion of cold fluids and ice slurry, both with and without menthol, as well as cooling of the neck and face region via a cooling collar or water poured on the head and face. The combination of pre-cooling and mid-cooling has also been effective, but few comparisons exist between the timing and type of such interventions. Therefore, athletes should experiment with a range of suitable mid-cooling strategies for their event during mock competition scenarios, with the aim to determine their individual tolerable limits and performance benefits. Based on current evidence, the effect of mid-cooling on core temperature appears largely irrelevant to any subsequent performance improvements, while cardiovascular, skin temperature, central nervous system function and psychophysiological factors are likely involved. Research is lacking on elite athletes, and as such it is currently unclear how this population may benefit from mid-cooling.

  13. Direct healthcare costs of selected diseases primarily or partially transmitted by water.

    Science.gov (United States)

    Collier, S A; Stockman, L J; Hicks, L A; Garrison, L E; Zhou, F J; Beach, M J

    2012-11-01

    Despite US sanitation advancements, millions of waterborne disease cases occur annually, although the precise burden of disease is not well quantified. Estimating the direct healthcare cost of specific infections would be useful in prioritizing waterborne disease prevention activities. Hospitalization and outpatient visit costs per case and total US hospitalization costs for ten waterborne diseases were calculated using large healthcare claims and hospital discharge databases. The five primarily waterborne diseases in this analysis (giardiasis, cryptosporidiosis, Legionnaires' disease, otitis externa, and non-tuberculous mycobacterial infection) were responsible for over 40 000 hospitalizations at a cost of $970 million per year, including at least $430 million in hospitalization costs for Medicaid and Medicare patients. An additional 50 000 hospitalizations for campylobacteriosis, salmonellosis, shigellosis, haemolytic uraemic syndrome, and toxoplasmosis cost $860 million annually ($390 million in payments for Medicaid and Medicare patients), a portion of which can be assumed to be due to waterborne transmission.

  14. Temporal integration of loudness in listeners with hearing losses of primarily cochlear origin

    DEFF Research Database (Denmark)

    Buus, Søren; Florentine, Mary; Poulsen, Torben

    1999-01-01

    To investigate how hearing loss of primarily cochlear origin affects the loudness of brief tones, loudness matches between 5- and 200-ms tones were obtained as a function of level for 15 listeners with cochlear impairments and for seven age-matched controls. Three frequencies, usually 0.5, 1, and 4...... of temporal integration—defined as the level difference between equally loud short and long tones—varied nonmonotonically with level and was largest at moderate levels. No consistent effect of frequency was apparent. The impaired listeners varied widely, but most showed a clear effect of level on the amount...... of temporal integration. Overall, their results appear consistent with expectations based on knowledge of the general properties of their loudness-growth functions and the equal-loudness-ratio hypothesis, which states that the loudness ratio between equal-SPL long and brief tones is the same at all SPLs...

  15. The Serotonin Transporter Undergoes Constitutive Internalization and Is Primarily Sorted to Late Endosomes and Lysosomal Degradation*

    Science.gov (United States)

    Rahbek-Clemmensen, Troels; Bay, Tina; Eriksen, Jacob; Gether, Ulrik; Jørgensen, Trine Nygaard

    2014-01-01

    The serotonin transporter (SERT) plays a critical role in regulating serotonin signaling by mediating reuptake of serotonin from the extracellular space. The molecular and cellular mechanisms controlling SERT levels in the membrane remain poorly understood. To study trafficking of the surface resident SERT, two functional epitope-tagged variants were generated. Fusion of a FLAG-tagged one-transmembrane segment protein Tac to the SERT N terminus generated a transporter with an extracellular epitope suited for trafficking studies (TacSERT). Likewise, a construct with an extracellular antibody epitope was generated by introducing an HA (hemagglutinin) tag in the extracellular loop 2 of SERT (HA-SERT). By using TacSERT and HA-SERT in antibody-based internalization assays, we show that SERT undergoes constitutive internalization in a dynamin-dependent manner. Confocal images of constitutively internalized SERT demonstrated that SERT primarily co-localized with the late endosomal/lysosomal marker Rab7, whereas little co-localization was observed with the Rab11, a marker of the “long loop” recycling pathway. This sorting pattern was distinct from that of a prototypical recycling membrane protein, the β2-adrenergic receptor. Furthermore, internalized SERT co-localized with the lysosomal marker LysoTracker and not with transferrin. The sorting pattern was further confirmed by visualizing internalization of SERT using the fluorescent cocaine analog JHC1-64 and by reversible and pulse-chase biotinylation assays showing evidence for lysosomal degradation of the internalized transporter. Finally, we found that SERT internalized in response to stimulation with 12-myristate 13-acetate co-localized primarily with Rab7- and LysoTracker-positive compartments. We conclude that SERT is constitutively internalized and that the internalized transporter is sorted mainly to degradation. PMID:24973209

  16. Aerobic endurance in HIV-positive young adults and HIV-negative ...

    African Journals Online (AJOL)

    Background: Aerobic endurance is an important aspect of physical fitness that enables individuals living with HIV to endure in the work place as well as in agricultural operations in order to earn a living and improve their quality of life. However, despite high HIV prevalence rates, the aerobic endurance status of young ...

  17. [Supplementary device for a dynamometer to evaluate and register muscular endurance indices].

    Science.gov (United States)

    Timoshenko, D A; Bokser, O Ia

    1986-01-01

    In practice of psychophysiologic research muscular endurance index is used for estimation of CNS function. Muscular endurance index is defined as relative time needed for maintaining the preset muscular effort. The described device widens the possibilities of a digital dynamometer for automatic estimation and recording of muscular endurance index in real time.

  18. 76 FR 72243 - Proposed Information Collection (Operation Enduring Freedom/Operation Iraqi Freedom Veterans...

    Science.gov (United States)

    2011-11-22

    ... (Operation Enduring Freedom/ Operation Iraqi Freedom Veterans Health Needs Assessment) Activity; Comment... Operation Enduring Freedom/ Operation Iraqi Freedom veterans and their families. DATES: Written comments and...: Operation Enduring Freedom/Operation Iraqi Freedom Veterans Health Needs Assessment, VA Form 10-21091. OMB...

  19. 76 FR 58565 - Proposed Information Collection (Operation Enduring Freedom/Operation Iraqi Freedom Seriously...

    Science.gov (United States)

    2011-09-21

    ... (Operation Enduring Freedom/ Operation Iraqi Freedom Seriously Injured/Ill Service Member Veteran Worksheet... solicits comments on information provided to Operation Enduring Freedom/Operation Iraqi Freedom veterans... information technology. Title: Operation Enduring Freedom/Operation Iraqi Freedom Seriously Injured/Ill...

  20. 76 FR 73022 - Agency Information Collection (Operation Enduring Freedom/Operation Iraqi Freedom Seriously...

    Science.gov (United States)

    2011-11-28

    ... (Operation Enduring Freedom/ Operation Iraqi Freedom Seriously Injured/Ill Service Member Veteran Worksheet... No. 2900-0720.'' SUPPLEMENTARY INFORMATION: Title: Operation Enduring Freedom/Operation Iraqi Freedom... used VA Form 21-0773 as a checklist to ensure they provided Operation Enduring Freedom or Operation...

  1. Effects of Plyometric Training and Beta-Alanine Supplementation on Maximal-Intensity Exercise and Endurance in Female Soccer Players

    Directory of Open Access Journals (Sweden)

    Rosas Fabián

    2017-08-01

    Full Text Available Plyometric training and beta-alanine supplementation are common among soccer players, although its combined use had never been tested. Therefore, a randomized, double-blind, placebo-controlled trial was conducted to compare the effects of a plyometric training program, with or without beta-alanine supplementation, on maximal-intensity and endurance performance in female soccer players during an in-season training period. Athletes (23.7 ± 2.4 years were assigned to either a plyometric training group receiving a placebo (PLACEBO, n = 8, a plyometric training group receiving beta-alanine supplementation (BA, n = 8, or a control group receiving placebo without following a plyometric training program (CONTROL, n = 9. Athletes were evaluated for single and repeated jumps and sprints, endurance, and change-of-direction speed performance before and after the intervention. Both plyometric training groups improved in explosive jumping (ES = 0.27 to 1.0, sprinting (ES = 0.31 to 0.78, repeated sprinting (ES = 0.39 to 0.91, 60 s repeated jumping (ES = 0.32 to 0.45, endurance (ES = 0.35 to 0.37, and change-of-direction speed performance (ES = 0.36 to 0.58, whereas no significant changes were observed for the CONTROL group. Nevertheless, compared to the CONTROL group, only the BA group showed greater improvements in endurance, repeated sprinting and repeated jumping performances. It was concluded that beta-alanine supplementation during plyometric training may add further adaptive changes related to endurance, repeated sprinting and jumping ability.

  2. Effects of Plyometric Training and Beta-Alanine Supplementation on Maximal-Intensity Exercise and Endurance in Female Soccer Players.

    Science.gov (United States)

    Rosas, Fabián; Ramírez-Campillo, Rodrigo; Martínez, Cristian; Caniuqueo, Alexis; Cañas-Jamet, Rodrigo; McCrudden, Emma; Meylan, Cesar; Moran, Jason; Nakamura, Fábio Y; Pereira, Lucas A; Loturco, Irineu; Diaz, Daniela; Izquierdo, Mikel

    2017-09-01

    Plyometric training and beta-alanine supplementation are common among soccer players, although its combined use had never been tested. Therefore, a randomized, double-blind, placebo-controlled trial was conducted to compare the effects of a plyometric training program, with or without beta-alanine supplementation, on maximal-intensity and endurance performance in female soccer players during an in-season training period. Athletes (23.7 ± 2.4 years) were assigned to either a plyometric training group receiving a placebo (PLACEBO, n = 8), a plyometric training group receiving beta-alanine supplementation (BA, n = 8), or a control group receiving placebo without following a plyometric training program (CONTROL, n = 9). Athletes were evaluated for single and repeated jumps and sprints, endurance, and change-of-direction speed performance before and after the intervention. Both plyometric training groups improved in explosive jumping (ES = 0.27 to 1.0), sprinting (ES = 0.31 to 0.78), repeated sprinting (ES = 0.39 to 0.91), 60 s repeated jumping (ES = 0.32 to 0.45), endurance (ES = 0.35 to 0.37), and change-of-direction speed performance (ES = 0.36 to 0.58), whereas no significant changes were observed for the CONTROL group. Nevertheless, compared to the CONTROL group, only the BA group showed greater improvements in endurance, repeated sprinting and repeated jumping performances. It was concluded that beta-alanine supplementation during plyometric training may add further adaptive changes related to endurance, repeated sprinting and jumping ability.

  3. The effect of endurance training on muscle strength in young, healthy men in relation to hormonal status.

    Science.gov (United States)

    Grandys, M; Majerczak, J; Duda, K; Zapart-Bukowska, J; Sztefko, K; Zoladz, J A

    2008-12-01

    The objective of this study was to establish the effect of moderate intensity endurance training on muscle strength in relation to hormonal changes in the body. Fifteen young, healthy men took part in 5 week endurance training performed on a cycloergometer. Before and after training program, exercise testing sessions were performed involving all participants. Training program significantly increased V(O2 max) (P<0.05) and time to fatigue at 50% of maximal voluntary isometric contraction (TTF 50% MVC), P<0.03, but it did not affect maximal voluntary isometric contraction (MVC). This was accompanied by an increase (P<0.001) in total plasma testosterone (T) and free testosterone (fT) concentrations, whereas a decrease in sex hormone-binding globulin (SHBG) (P<0.02), growth hormone (P<0.05), free triiodothyronine (P<0.001) and free thyroxine (P<0.02) concentrations was observed. No changes were found in plasma cortisol (C) and insulin-like growth factor-I (IGF-I) concentrations. Additionally, MVC was positively correlated to T/C, fT/C and IGF-I/C ratios after the training, whereas time to fatigue at 50% of MVC was closely positively correlated to the SHBG concentration, both before and after endurance training. We have concluded that moderate intensity endurance training resulting in a significant increase in V(O2 max), did not affect the MVC, but it significantly increased time to fatigue at 50% of MVC. This index of local muscular endurance was greater in subjects with higher concentration of SHBG, both before and after the training.

  4. Quadriceps Strength and Endurance After Posterior Cruciate Ligament Tears Versus Matched Group With Anterior Cruciate Ligament Tears.

    Science.gov (United States)

    Lee, Dae-Hee; Han, Seung-Beom; Lee, Jin-Hyuck; Lee, Seok-Joo; Suh, Dong-Won; Jeong, Hye-Jin

    2015-06-01

    This study was designed to compare the preoperative strengths and endurances of the quadriceps and hamstring muscles in patients with anterior cruciate ligament (ACL) versus posterior cruciate ligament (PCL) tears. Quadriceps and hamstring muscle strength and endurance were compared between 20 prospectively enrolled patients with isolated PCL tears and a retrospective, matched control group of 20 patients with isolated ACL tears. The maximal torque (60°/s) and total work (180°/s) of the quadriceps and hamstring were evaluated with an isokinetic testing device. Total work (1,094.4 ± 505.8 J v 797.5 ± 332.7 J, P = .035) and peak torque (129.9 ± 56.2 N ∙ m v 98.2 ± 37.4 N ∙ m, P = .046) of the quadriceps muscle on the involved side were higher in the PCL tear group than in the ACL tear group. However, there were no significant differences between the PCL tear group and ACL tear group in hamstring muscle strength (45.8 ± 42.3 N ∙ m and 46.0 ± 24.4 N ∙ m, respectively; P = .940) and endurance (429.3 ± 238.9 J and 382.4 ± 256.1 J, respectively; P = .574) on the involved side. The strength and endurance of the quadriceps muscle of the injured limb were greater after PCL tears than after ACL tears. However, there were no significant between-group differences in hamstring muscle strength and endurance on the involved side. Level III, retrospective comparative study. Copyright © 2015 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  5. Assessing the Level of Disability, Deep Cervical Flexor Endurance and Fear Avoidance Beliefs in Bankers with Neck Pain

    Directory of Open Access Journals (Sweden)

    Deptee Warikoo

    2013-08-01

    Full Text Available Objective: To assess the level of disability, the deep cervical flexor endurance and fear avoidance beliefs (FAB in bankers with neck pain and to find a correlation between disability and deep cervical muscle endurance, FAB and disability, FAB and deep flexor muscle endurance. Methods: It ws an observational study. The Subjects who had neck pain and minimum 5 years’ experience as a Banker participated in the study. Total 100 subjects were selected. All the subjects were assessed for their disability by the neck pain and disability score (NPDI, their deep cervical flexor endurance using Pressure Biofeedback using Cranio-Cervical flexion test (CCFT and Fear Avoidance Belief by using questionnaire( FABQ. Results: It was found that bankers have a moderate level of disability. The results showed an elevated fear avoidance belief with a mean value of FABQ-PA 21.61±4.42 and FABQ-W 37.81± 5.69. The results indicated that a negative correlation was found between NPDI and CCFT (r=0.855. A positive correlation was found between NPDI and FABQ-PA(r=0.337, FABQ-W(r=0.500. In the present study a negative correlation was found between CCFT and FABQ-W(r=0.553, FABQ-PA (0.348 and positive correlation (r=0.540 was found between FABQ-PA and FABQ-W. Conclusion: The present study concluded that there was a significant level of disability and significantly decreased endurance level and increased fear avoidance beliefs (both work and physical activity related among bankers with neck pain. In addition to that there was a significant correlation found between NPDI and CCFT, NPDI and FABQ, CCFT and FABQ, FABQ-W and FABQ-PA.

  6. Can a pilates exercise program be effective on balance, flexibility and muscle endurance? A randomized controlled trial.

    Science.gov (United States)

    Kibar, Sibel; Yardimci, Fatma Ö; Evcik, Deniz; Ay, Saime; Alhan, Aslıhan; Manço, Miray; Ergin, Emine S

    2016-10-01

    This randomized controlled study aims to determine the effect of pilates mat exercises on dynamic and static balance, hamstring flexibility, abdominal muscle activity and endurance in healthy adults. Female healthy volunteer university students randomly assigned into two groups. Group 1 followed a pilates program for an hour two times a week. Group 2 continued daily activities as control group. Dynamic and static balance were evaluated by Sport Kinesthetic Ability Trainer (KAT) 4000 device. Hamstring flexibility and abdominal endurance were determined by sit-and-reach test, curl-up test respectively. Pressure biofeedback unit (PBU) was used to measure transversus abdominis and lumbar muscle activity. The physical activity of the participants was followed by International Physical Activity Questionnaire-Short Form. Twenty-three subjects in pilates group and 24 control subjects completed the study. In pilates group, statistical significant improvements were observed in curl-up, sit-and-reach test, PBU scores at sixth week (Ppilates group for sit-and-reach test (P=0.01) and PBU scores (Ppilates training program has been found to have beneficial effect on static balance, flexibility, abdominal muscle endurance, abdominal and lumbar muscle activity. These parameters have no effect on balance.

  7. Serotonin-mediated central fatigue underlies increased endurance capacity in mice from lines selectively bred for high voluntary wheel running.

    Science.gov (United States)

    Claghorn, Gerald C; Fonseca, Ivana A T; Thompson, Zoe; Barber, Curtis; Garland, Theodore

    2016-07-01

    Serotonin (5-hydroxytryptamine; 5-HT) is implicated in central fatigue, and 5-HT1A pharmaceuticals are known to influence locomotor endurance in both rodents and humans. We studied the effects of a 5-HT1A agonist and antagonist on both forced and voluntary exercise in the same set of mice. This cohort of mice was taken from 4 replicate lines of mice that have been selectively bred for high levels of voluntary wheel running (HR) as compared with 4 non-selected control (C) lines. HR mice run voluntarily on wheels about 3× as many revolutions per day as compared with C, and have greater endurance during forced treadmill exercise. We hypothesized that drugs targeting serotonin receptors would have differential effects on locomotor behavior of HR and C mice. Subcutaneous injections of a 5-HT1A antagonist (WAY-100,635), a combination of 5-HT1A agonist and a 5-HT1A/1B partial agonist (8-OH-DPAT+pindolol), or physiological saline were given to separate groups of male mice before the start of each of three treadmill trials. The same manipulations were used later during voluntary wheel running on three separate nights. WAY-100,635 decreased treadmill endurance in HR but not C mice (dose by linetype interaction, P=0.0014). 8-OH-DPAT+pindolol affected treadmill endurance (PWheel running was reduced in HR but not C mice at the highest dose of 8-OH-DPAT+pindolol (dose by linetype, P=0.0221), but was not affected by WAY-100,635 treatment. These results provide further evidence that serotonin signaling is an important determinant of performance during both forced and voluntary exercise. Although the elevated wheel running of HR mice does not appear related to alterations in serotonin signaling, their enhanced endurance capacity does. More generally, our results indicate that both forced and voluntary exercise can be affected by an intervention that acts (primarily) centrally. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Strength, Endurance, Throwing Velocity and in-Water Jump Performance of Elite German Water Polo Players

    Directory of Open Access Journals (Sweden)

    Zinner Christoph

    2015-03-01

    Full Text Available The purpose of this study was threefold: 1 to assess the eggbeater kick and throwing performance using a number of water polo specific tests, 2 to explore the relation between the eggbeater kick and throwing performance, and 3 to investigate the relation between the eggbeater kick in the water and strength tests performed in a controlled laboratory setting in elite water polo players. Fifteen male water polo players of the German National Team completed dynamic and isometric strength tests for muscle groups (adductor, abductor, abdominal, pectoralis frequently used during water polo. After these laboratory strength tests, six water polo specific in-water tests were conducted. The eggbeater kick assessed leg endurance and agility, maximal throwing velocity and jump height. A 400 m test and a sprint test examined aerobic and anaerobic performance. The strongest correlation was found between jump height and arm length (p < 0.001, r = 0.89. The laboratory diagnostics of important muscles showed positive correlations with the results of the in-water tests (p < 0.05, r = 0.52-0.70. Muscular strength of the adductor, abdominal and pectoralis muscles was positively related to in-water endurance agility as assessed by the eggbeater kick (p < 0.05; r = 0.53-0.66. Findings from the current study emphasize the need to assess indices of water polo performance both in and out of the water as well as the relation among these parameters to best assess the complex profile of water polo players.

  9. Keto-adaptation enhances exercise performance and body composition responses to training in endurance athletes.

    Science.gov (United States)

    McSwiney, Fionn T; Wardrop, Bruce; Hyde, Parker N; Lafountain, Richard A; Volek, Jeff S; Doyle, Lorna

    2018-04-01

    Low-carbohydrate diets have recently grown in popularity among endurance athletes, yet little is known about the long-term (>4wk) performance implications of consuming a low-carbohydrate high fat ketogenic diet (LCKD) in well-trained athletes. Twenty male endurance-trained athletes (age 33±11y, body mass 80±11kg; BMI 24.7±3.1kg/m 2 ) who habitually consumed a carbohydrate-based diet, self-selected into a high-carbohydrate (HC) group (n=11, %carbohydrate:protein:fat=65:14:20), or a LCKD group (n=9, 6:17:77). Both groups performed the same training intervention (endurance, strength and high intensity interval training (HIIT)). Prior to and following successful completion of 12-weeks of diet and training, participants had their body composition assessed, and completed a 100km time trial (TT), six second (SS) sprint, and a critical power test (CPT). During post-intervention testing the HC group consumed 30-60g/h carbohydrate, whereas the LCKD group consumed water, and electrolytes. The LCKD group experienced a significantly greater decrease in body mass (HC -0.8kg, LCKD -5.9kg; P=0.006, effect size (ES): 0.338) and percentage body fat percentage (HC -0.7%, LCKD -5.2%; P=0.008, ES: 0.346). Fasting serum beta-hydroxybutyrate (βHB) significantly increased from 0.1 at baseline to 0.5mmol/L in the LCKD group (P=0.011, ES: 0.403) in week 12. There was no significant change in performance of the 100km TT between groups (HC -1.13min·s, LCKD -4.07min·s, P=0.057, ES: 0.196). SS sprint peak power increased by 0.8 watts per kilogram bodyweight (w/kg) in the LCKD group, versus a -0.1w/kg reduction in the HC group (P=0.025, ES: 0.263). CPT peak power decreased by -0.7w/kg in the HC group, and increased by 1.4w/kg in the LCKD group (P=0.047, ES: 0.212). Fat oxidation in the LCKD group was significantly greater throughout the 100km TT. Compared to a HC comparison group, a 12-week period of keto-adaptation and exercise training, enhanced body composition, fat oxidation during

  10. Associations between Trunk Extension Endurance and Isolated Lumbar Extension Strength in Both Asymptomatic Participants and Those with Chronic Low Back Pain

    Directory of Open Access Journals (Sweden)

    Rebecca Conway

    2016-09-01

    Full Text Available Background: Strength and endurance tests are important for both clinical practice and research due to the key role they play in musculoskeletal function. In particular, deconditioning of the lumbar extensor musculature has been associated with low back pain (LBP. Due to the relationship between strength and absolute endurance, it is possible that trunk extension (TEX endurance tests could provide a proxy measure of isolated lumbar extension (ILEX strength and thus represent a simple, practical alternative to ILEX measurements. Though, the comparability of TEX endurance and ILEX strength is presently unclear and so the aim of the present study was to examine this relationship. Methods: Thirty eight healthy participants and nineteen participants with non-specific chronic LBP and no previous lumbar surgery participated in this cross-sectional study design. TEX endurance was measured using the Biering–Sorensen test. A maximal ILEX strength test was performed on the MedX lumbar-extension machine. Results: A Pearson’s correlation revealed no relationship between TEX endurance and ILEX strength in the combined group (r = 0.035, p = 0.793, the chronic LBP group (r = 0.120, p = 0.623 or the asymptomatic group (r = −0.060, p = 0.720. Conclusions: The results suggest that TEX is not a good indicator of ILEX and cannot be used to infer results regarding ILEX strength. However, a combination of TEX and ILEX interpreted together likely offers the greatest and most comprehensive information regarding lumbo-pelvic function during extension.

  11. SOFC Systems with Improved Reliability and Endurance

    Energy Technology Data Exchange (ETDEWEB)

    Ghezel-Ayagh, Hossein [Fuelcell Energy, Incorporated, Danbury, CT (United States)

    2015-12-31

    The overall goal of this U.S. Department of Energy (DOE) sponsored project was the development of Solid Oxide Fuel Cell (SOFC) technology suitable for ultra-efficient central power generation systems utilizing coal and natural gas fuels and featuring greater than 90% carbon dioxide capture. The specific technical objective of this project was to demonstrate, via analyses and testing, progress towards adequate stack life (≥ 4 years) and stack performance stability (degradation rate ≤ 0.2% per 1000 hours) in a low-cost SOFC stack design. This final technical report summarizes the progress made during the project period of 27 months. Significant progress was made in the areas of cell and stack technology development, stack module development, sub-scale module tests, and Proof-of-Concept Module unit design, fabrication and testing. The work focused on cell and stack materials and designs, balance-of-plant improvements, and performance evaluation covering operating conditions and fuel compositions anticipated for commercially-deployed systems. In support of performance evaluation under commercial conditions, this work included the design, fabrication, siting, commissioning, and operation of a ≥ 50 kWe proof-of-concept module (PCM) power plant, based upon SOFC cell and stack technology developed to date by FuelCell Energy, Inc. (FCE) under the Office of Fossil Energy’s Solid Oxide Fuel Cells program. The PCM system was operated for at least 1000 hours on natural gas fuel at FCE’s facility. The factory cost of the SOFC stack was estimated to be at or below the DOE’s high-volume production cost target (2011 $).

  12. The development and characterization of a primarily mineral calcium phosphate - poly(epsilon-caprolactone) biocomposite

    Science.gov (United States)

    Dunkley, Ian Robert

    Orthopaedic reconstruction often involves the surgical introduction of structural implants that provide for rigid fixation, skeletal stabilization, and bone integration. The high stresses incurred by these implanted devices have historically limited material choices to metallic and select polymeric formulations. While mechanical requirements are achieved, these non-degradable materials do not participate actively in the remodeling of the skeleton and present the possibility of long-term failure or rejection. This is particularly relevant in cervical fusion, an orthopaedic procedure to treat damaged, degenerative or diseased intervertebral discs. A significant improvement on the available synthetic bone replacement/regeneration options for implants to treat these conditions in the cervical spine may be achieved with the development of primarily mineral biocomposites comprised of a bioactive ceramic matrix reinforced with a biodegradable polymer. Such a biocomposite may be engineered to possess the clinically required mechanical properties of a particular application, while maintaining the ability to be remodeled completely by the body. A biocomposite of Si-doped calcium phosphate (Si-CaP) and poly(epsilon-caprolactone) (PCL) was developed for application as such a synthetic bone material for potential use as a fusion device in the cervical spine. In this thesis, a method by which high mineral content Si-CaP/PCL biocomposites with interpenetrating matrices of mineral and polymer phases may be prepared will be demonstrated, in addition to the effects of the various preparation parameters on the biocomposite density, porosity and mechanical properties. This new technique by which dense, primarily ceramic Si-CaP/PCL biocomposites were prepared, allowed for the incorporation of mineral contents ranging between 45-97vol%. Polymer infiltration, accomplished solely by passive capillary uptake over several days, was found to be capable of fully infiltrating the microporosity

  13. Development and Sensitivity Analysis of a Frost Risk model based primarily on freely distributed Earth Observation data

    Science.gov (United States)

    Louka, Panagiota; Petropoulos, George; Papanikolaou, Ioannis

    2015-04-01

    The ability to map the spatiotemporal distribution of extreme climatic conditions, such as frost, is a significant tool in successful agricultural management and decision making. Nowadays, with the development of Earth Observation (EO) technology, it is possible to obtain accurately, timely and in a cost-effective way information on the spatiotemporal distribution of frost conditions, particularly over large and otherwise inaccessible areas. The present study aimed at developing and evaluating a frost risk prediction model, exploiting primarily EO data from MODIS and ASTER sensors and ancillary ground observation data. For the evaluation of our model, a region in north-western Greece was selected as test site and a detailed sensitivity analysis was implemented. The agreement between the model predictions and the observed (remotely sensed) frost frequency obtained by MODIS sensor was evaluated thoroughly. Also, detailed comparisons of the model predictions were performed against reference frost ground observations acquired from the Greek Agricultural Insurance Organization (ELGA) over a period of 10-years (2000-2010). Overall, results evidenced the ability of the model to produce reasonably well the frost conditions, following largely explainable patterns in respect to the study site and local weather conditions characteristics. Implementation of our proposed frost risk model is based primarily on satellite imagery analysis provided nowadays globally at no cost. It is also straightforward and computationally inexpensive, requiring much less effort in comparison for example to field surveying. Finally, the method is adjustable to be potentially integrated with other high resolution data available from both commercial and non-commercial vendors. Keywords: Sensitivity analysis, frost risk mapping, GIS, remote sensing, MODIS, Greece

  14. An investigation of the tri-bar gripping system on isometric muscular endurance.

    Science.gov (United States)

    Drury, Daniel G; Faggiono, Heath; Stuempfle, Kristin J

    2004-11-01

    Recently, a new product called the Tri-Bar has been introduced as an alternative to the standard round weightlifting bar. The Tri-Bar has the same weight, length, and circumference as a standard weightlifting bar and differs only in that the shape of the bar is formed like a triangle with rounded edges. Theoretically, the shape of the bar will enhance gripping comfort and increase muscular endurance. We studied 32 moderately trained males who were free from upper-body injury or limitation. Each participant completed 4 visits to the lab as part of 2 separate investigations. The first investigation was a comparison of straight-arm hang times while grasping a standard Olympic bar or a Tri-Bar attached to the top of a power rack. The second investigation involved grasping a standard revolving cable handle or a Tri-Bar revolving handle attached to a weight equal to half the subject's body weight. In both investigations, time was used as a measure of isometric muscular endurance. Differences were determined using a dependent t-test, and a level of significance was set at p < 0.05. Mean hang times were significantly longer when the men hung from the Tri-Bar (107.6 seconds) versus the standard bar (95.4 seconds) (p = 0.015). Conversely, in the investigation using the revolving handles, the round bar produced longer grasping times (71.5 seconds) than the Tri-Bar (62.6 seconds) (p = 0.000). The results of this investigation indicate that a fixed and stable Tri-Bar may help to increase hang time, but a Tri-Bar free to rotate within the grasp may decrease grasping time in comparison to a standard round handle. With regard to exercises that require isometric grasping, the Tri-Bar may be an effective alternative to the standard bar for increasing isometric grasping endurance.

  15. Isokinetic strength and endurance after percutaneous and open surgical repair of Achilles tendon ruptures.

    Science.gov (United States)

    Goren, David; Ayalon, Moshe; Nyska, Meir

    2005-04-01

    Reports on complete spontaneous Achilles tendon ruptures and associated treatment have become more frequent in the literature in the past two decades, as has the request for treatments that enable the finest possible functional recovery. The best available treatment is a matter of considerable controversy in the literature. The purpose of this study was to compare the isokinetic strength and endurance of the plantarflexor muscle-tendon unit in subjects who sustained rupture of the Achilles tendon and underwent either open surgery or closed percutaneous repair of the Achilles tendon. Twenty patients (18 males, 2 females) with spontaneous ruptures of the Achilles tendon were included in this study. Ten patients were treated by open surgery, and 10 patients were treated percutaneously. All patients had ruptured their Achilles tendon more than 6 months before the study, and all of the ruptures occurred 3.5 years or less before the day of the testing. All patients underwent an oriented physical examination. An isokinetic Biodex dynamometer (Biodex Medical System, Shirley, NY) was used to measure ankle joint angle, and in plantarflexion to calculate the torque at the ankle joint (Newton/meter), and the average work (jouls) for both maximal power and endurance. Each measurement was compared to the normal ankle. Biodex dynamometer evaluations at 90 deg/sec demonstrated a significant difference of maximal voluntary plantarflexor torque, endurance performance and range of motion at the ankle joint between the involved and uninvolved sides in patients treated by either mode of treatment. Yet, no statistically significant differences were revealed for the parameters mentioned above between the subjects that were treated either percutaneously or by an open surgery. In functional terms, the biomechanical outcomes of open surgery and percutaneous repair for acute ruptures of the Achilles tendon are both effective.

  16. Endurance training of moderate intensity increases testosterone concentration in young, healthy men.

    Science.gov (United States)

    Grandys, M; Majerczak, J; Duda, K; Zapart-Bukowska, J; Kulpa, J; Zoladz, J A

    2009-07-01

    The aim of this study was to investigate the effect of short-term, moderate intensity and low volume endurance training on gonadal hormone profile in untrained men. Fifteen young, healthy men performed an endurance training of 5-week duration on a cycle ergometer. Before and after the exercise program all participants completed a maximal incremental test. Concentration of testosterone (T), sex hormone-binding globulin (SHBG) and cortisol (C) as well as blood morphology were determined in venous blood samples at rest both before and after the training. The training program resulted in 3.7% improvement of maximal oxygen uptake (VO(2max)) and 8.2% improvement of power output reached at VO(2max) (PO (max)). This was accompanied by significant increase in T (from 18.84+/-5.73 nmol.l(-1) to 22.03+/-6.61 nmol.l(-1), p = 0.0004) and calculated fT concentration (from 374+/-116 pmol.l(-1) to 470+/-153 pmol.l(-1), p = 0.00005). Moreover, the training caused a significant decrease in SHBG concentration (from 34.45+/-11.26 nmol.l(-1) to 31.95+/-10.40 nmol.l(-1), p = 0.01), whereas no significant changes were found in the cortisol concentration (334+/-138 nmol.l(-1) vs. 367+/-135 nmol.l(-1) for pre- and post-training measures, respectively, p = 0.50) and T/C and fT/C ratios. We have concluded that short-term, moderate intensity and low volume endurance training can significantly increase testosterone concentration in previously untrained men.

  17. Astrocytic glycogen-derived lactate fuels the brain during exhaustive exercise to maintain endurance capacity.

    Science.gov (United States)

    Matsui, Takashi; Omuro, Hideki; Liu, Yu-Fan; Soya, Mariko; Shima, Takeru; McEwen, Bruce S; Soya, Hideaki

    2017-06-13

    Brain glycogen stored in astrocytes provides lactate as an energy source to neurons through monocarboxylate transporters (MCTs) to maintain neuronal functions such as hippocampus-regulated memory formation. Although prolonged exhaustive exercise decreases brain glycogen, the role of this decrease and lactate transport in the exercising brain remains less clear. Because muscle glycogen fuels exercising muscles, we hypothesized that astrocytic glycogen plays an energetic role in the prolonged-exercising brain to maintain endurance capacity through lactate transport. To test this hypothesis, we used a rat model of exhaustive exercise and capillary electrophoresis-mass spectrometry-based metabolomics to observe comprehensive energetics of the brain (cortex and hippocampus) and muscle (plantaris). At exhaustion, muscle glycogen was depleted but brain glycogen was only decreased. The levels of MCT2, which takes up lactate in neurons, increased in the brain, as did muscle MCTs. Metabolomics revealed that brain, but not muscle, ATP was maintained with lactate and other glycogenolytic/glycolytic sources. Intracerebroventricular injection of the glycogen phosphorylase inhibitor 1,4-dideoxy-1,4-imino-d-arabinitol did not affect peripheral glycemic conditions but suppressed brain lactate production and decreased hippocampal ATP levels at exhaustion. An MCT2 inhibitor, α-cyano-4-hydroxy-cinnamate, triggered a similar response that resulted in lower endurance capacity. These findings provide direct evidence for the energetic role of astrocytic glycogen-derived lactate in the exhaustive-exercising brain, implicating the significance of brain glycogen level in endurance capacity. Glycogen-maintained ATP in the brain is a possible defense mechanism for neurons in the exhausted brain.

  18. Tolerance of Lower Body Negative Pressure (LBNP) in endurance runners, weightlifters, swimmers and nonathletes

    Science.gov (United States)

    1980-01-01

    Thirteen endurance runners (R), 12 weightlifters (WL), 12 swimmers (SW) and 10 nonathletes (NA) were tested for their tolerance of lower body negative pressure (LBNP) in consecutive 5 minute stages at -20, -30, -40, -50 and -60 torr. Each subject also performed an exercise test on a bicycle ergometer with progressive workloads to exhaustion to determined aerobic capacity. The R had a much higher aerobic capacity than any of the other groups, but a significantly lower LBNP tolerance. While responses in heart rate and pulse pressure were quite similar in all 4 groups, the rate of increase in leg volume relative to LBNP stress (leg compliance, LC) was considerably greater in R than in the other athletes and NA. The greater LC in R could be attributed not only to a more rapid shift of blood to the lower extremities but also to a greater tendency for edema formation, both contributing to a more rapid loss in effective central blood volume for a given LBNP stress. These results substantiate earlier observations which led to the conclusion that endurance running is not advisable as a training regimen for astronauts.

  19. Should Body Size Categories Be More Common in Endurance Running Events?

    Science.gov (United States)

    Buresh, Robert

    2018-05-01

    Thousands of endurance running events are held each year in the United States, and most of them use age and sex categories to account for documented effects of those factors on running performance. However, most running events do not provide categories of body mass, despite abundant evidence that it, too, dramatically influences endurance running performance. The purposes of this article are to (1) discuss how body mass affects endurance running performance, (2) explain several mechanisms through which body mass influences endurance running performance, and (3) suggest possible ways in which body mass might be categorized in endurance running events.

  20. Endurance training enhances skeletal muscle interleukin-15 in human male subjects

    DEFF Research Database (Denmark)

    Rinnov, Anders; Yfanti, Christina; Nielsen, Søren

    2014-01-01

    Regular endurance exercise promotes metabolic and oxidative changes in skeletal muscle. Overexpression of interleukin-15 (IL-15) in mice exerts similar metabolic changes in muscle as seen with endurance exercise. Muscular IL-15 production has been shown to increase in mice after weeks of regular...... endurance running. With the present study we aimed to determine if muscular IL-15 production would increase in human male subjects following 12 weeks of endurance training. In two different studies we obtained plasma and muscle biopsies from young healthy subjects performing: (1) 12 weeks of ergometer...... weeks of regular endurance training induced a 40% increase in basal skeletal muscle IL-15 protein content (p...

  1. Efficient transfection of DNA into primarily cultured rat sertoli cells by electroporation.

    Science.gov (United States)

    Li, Fuping; Yamaguchi, Kohei; Okada, Keisuke; Matsushita, Kei; Enatsu, Noritoshi; Chiba, Koji; Yue, Huanxun; Fujisawa, Masato

    2013-03-01

    The expression of exogenous DNA in Sertoli cells is essential for studying its functional genomics, pathway analysis, and medical applications. Electroporation is a valuable tool for nucleic acid delivery, even in primarily cultured cells, which are considered difficult to transfect. In this study, we developed an optimized protocol for electroporation-based transfection of Sertoli cells and compared its efficiency with conventional lipofection. Sertoli cells were transfected with pCMV-GFP plasmid by square-wave electroporation under different conditions. After transfection of plasmid into Sertoli cells, enhanced green fluorescent protein (EGFP) expression could be easily detected by fluorescent microscopy, and cell survival was evaluated by dye exclusion assay using Trypan blue. In terms of both cell survival and the percentage expressing EGFP, 250 V was determined to produce the greatest number of transiently transfected cells. Keeping the voltage constant (250 V), relatively high cell survival (76.5% ± 3.4%) and transfection efficiency (30.6% ± 5.6%) were observed with a pulse length of 20 μm. The number of pulses significantly affected cell survival and EGFP expression (P transfection methods, the transfection efficiency of electroporation (21.5% ± 5.7%) was significantly higher than those of Lipofectamine 2000 (2.9% ± 1.0%) and Effectene (1.9% ± 0.8%) in this experiment (P transfection of Sertoli cells.

  2. Perceptions of Mindfulness in a Low-income, Primarily African American Treatment-Seeking Sample.

    Science.gov (United States)

    Spears, Claire Adams; Houchins, Sean C; Bamatter, Wendy P; Barrueco, Sandra; Hoover, Diana Stewart; Perskaudas, Rokas

    2017-12-01

    Individuals with low socioeconomic status (SES) and members of racial/ethnic minority groups often experience profound disparities in mental health and physical well-being. Mindfulness-based interventions show promise for improving mood and health behaviors in higher-SES and non-Latino White populations. However, research is needed to explore what types of adaptations, if any, are needed to best support underserved populations. This study used qualitative methods to gain information about a) perceptions of mindfulness, b) experiences with meditation, c) barriers to practicing mindfulness, and d) recommendations for tailoring mindfulness-based interventions in a low-income, primarily African American treatment-seeking sample. Eight focus groups were conducted with 32 adults (16 men and 16 women) currently receiving services at a community mental health center. Most participants (91%) were African American. Focus group data were transcribed and analyzed using NVivo 10. A team of coders reviewed the transcripts to identify salient themes. Relevant themes included beliefs that mindfulness practice might improve mental health (e.g., managing stress and anger more effectively) and physical health (e.g., improving sleep and chronic pain, promoting healthier behaviors). Participants also discussed ways in which mindfulness might be consistent with, and even enhance, their religious and spiritual practices. Results could be helpful in tailoring mindfulness-based treatments to optimize feasibility and effectiveness for low-SES adults receiving mental health services.

  3. Identification of a novel CoA synthase isoform, which is primarily expressed in Brain

    International Nuclear Information System (INIS)

    Nemazanyy, Ivan; Panasyuk, Ganna; Breus, Oksana; Zhyvoloup, Alexander; Filonenko, Valeriy; Gout, Ivan T.

    2006-01-01

    CoA and its derivatives Acetyl-CoA and Acyl-CoA are important players in cellular metabolism and signal transduction. CoA synthase is a bifunctional enzyme which mediates the final stages of CoA biosynthesis. In previous studies, we have reported molecular cloning, biochemical characterization, and subcellular localization of CoA synthase (CoASy). Here, we describe the existence of a novel CoA synthase isoform, which is the product of alternative splicing and possesses a 29aa extension at the N-terminus. We termed it CoASy β and originally identified CoA synthase, CoASy α. The transcript specific for CoASy β was identified by electronic screening and by RT-PCR analysis of various rat tissues. The existence of this novel isoform was further confirmed by immunoblot analysis with antibodies directed to the N-terminal peptide of CoASy β. In contrast to CoASy α, which shows ubiquitous expression, CoASy β is primarily expressed in Brain. Using confocal microscopy, we demonstrated that both isoforms are localized on mitochondria. The N-terminal extension does not affect the activity of CoA synthase, but possesses a proline-rich sequence which can bring the enzyme into complexes with signalling proteins containing SH3 or WW domains. The role of this novel isoform in CoA biosynthesis, especially in Brain, requires further elucidation

  4. GOLD HULL AND INTERNODE2 encodes a primarily multifunctional cinnamyl-alcohol dehydrogenase in rice.

    Science.gov (United States)

    Zhang, Kewei; Qian, Qian; Huang, Zejun; Wang, Yiqin; Li, Ming; Hong, Lilan; Zeng, Dali; Gu, Minghong; Chu, Chengcai; Cheng, Zhukuan

    2006-03-01

    Lignin content and composition are two important agronomic traits for the utilization of agricultural residues. Rice (Oryza sativa) gold hull and internode phenotype is a classical morphological marker trait that has long been applied to breeding and genetics study. In this study, we have cloned the GOLD HULL AND INTERNODE2 (GH2) gene in rice using a map-based cloning approach. The result shows that the gh2 mutant is a lignin-deficient mutant, and GH2 encodes a cinnamyl-alcohol dehydrogenase (CAD). Consistent with this finding, extracts from roots, internodes, hulls, and panicles of the gh2 plants exhibited drastically reduced CAD activity and undetectable sinapyl alcohol dehydrogenase activity. When expressed in Escherichia coli, purified recombinant GH2 was found to exhibit strong catalytic ability toward coniferaldehyde and sinapaldehyde, while the mutant protein gh2 completely lost the corresponding CAD and sinapyl alcohol dehydrogenase activities. Further phenotypic analysis of the gh2 mutant plants revealed that the p-hydroxyphenyl, guaiacyl, and sinapyl monomers were reduced in almost the same ratio compared to the wild type. Our results suggest GH2 acts as a primarily multifunctional CAD to synthesize coniferyl and sinapyl alcohol precursors in rice lignin biosynthesis.

  5. GOLD HULL AND INTERNODE2 Encodes a Primarily Multifunctional Cinnamyl-Alcohol Dehydrogenase in Rice1

    Science.gov (United States)

    Zhang, Kewei; Qian, Qian; Huang, Zejun; Wang, Yiqin; Li, Ming; Hong, Lilan; Zeng, Dali; Gu, Minghong; Chu, Chengcai; Cheng, Zhukuan

    2006-01-01

    Lignin content and composition are two important agronomic traits for the utilization of agricultural residues. Rice (Oryza sativa) gold hull and internode phenotype is a classical morphological marker trait that has long been applied to breeding and genetics study. In this study, we have cloned the GOLD HULL AND INTERNODE2 (GH2) gene in rice using a map-based cloning approach. The result shows that the gh2 mutant is a lignin-deficient mutant, and GH2 encodes a cinnamyl-alcohol dehydrogenase (CAD). Consistent with this finding, extracts from roots, internodes, hulls, and panicles of the gh2 plants exhibited drastically reduced CAD activity and undetectable sinapyl alcohol dehydrogenase activity. When expressed in Escherichia coli, purified recombinant GH2 was found to exhibit strong catalytic ability toward coniferaldehyde and sinapaldehyde, while the mutant protein gh2 completely lost the corresponding CAD and sinapyl alcohol dehydrogenase activities. Further phenotypic analysis of the gh2 mutant plants revealed that the p-hydroxyphenyl, guaiacyl, and sinapyl monomers were reduced in almost the same ratio compared to the wild type. Our results suggest GH2 acts as a primarily multifunctional CAD to synthesize coniferyl and sinapyl alcohol precursors in rice lignin biosynthesis. PMID:16443696

  6. Increasing the electrical discharge endurance of acid anhydride cured DGEBA epoxy resin by dispersion of nanoparticle silica. High Perform. Polym. 11 (1999) pp 281-296 by IOP Publishing Ltd

    DEFF Research Database (Denmark)

    Henk, Peter O; Kortsen, T.W.; Kvarts, T.

    1999-01-01

    combinations were used: (a) fumed nanoparticle silicon dioxide referred to as Aerosil, (b) equal volumes of Aerosil and nanoparticle anatase, and (c) Aerosil plus anatase in combination with coarse-particle filler grade calcium-magnesium carbonate dolomite. A test for endurance using the CIGRE method II...... electrode arrangement was applied, the test comprising the establishment of partial discharges running perpendicularly onto one face of a plate specimen for a period measured until breakdown.Our results show that the endurance of the pure polymer is low. Increased loading with Aerosil increases...... the endurance by a factor of up to 20 as the Aerosil content goes from zero to 5.4 vol%. Aerosil mixed with anatase has a similar effect. The high level of endurance is maintained with an additional high-volume (35 vol.%) filling of coarse-particle dolomite to an epoxy system already containing Aerosil...

  7. Survival of the Fittest: Why Terrorist Groups Endure

    Directory of Open Access Journals (Sweden)

    Joseph K. Young

    2014-04-01

    Full Text Available Why do terrorist groups endure? This question is relevant to scholars and policy makers alike. In the past, this issue was not been addressed in a systematic fashion. Recent work investigates this question using data on transnational groups and finds that factors associated with the home country can influence the duration the group endures. Applying the theory of outbidding to terrorist group survival, we argue that strategic competition among groups predicts group duration. Using the Global Terrorism Database, we develop a dataset using the terrorist group as the unit of analysis to model the duration of group activity and thus include the largest sample of groups yet. Controlling for previous explanations of both group duration and terrorism, we find a robust effect for the impact that group competition has on terrorist group survival.

  8. The effects of endurance and resistance training on blood pressure.

    Science.gov (United States)

    Schwartz, R S; Hirth, V A

    1995-10-01

    There now exists substantial clinical data supporting a blood pressure lowering effect of endurance training. Though the effect is modest (5-10 mmHg), epidemiologic studies indicate the possibility of protection against the development of hypertension and also indicate significantly reduced cardiovascular mortality and increased longevity associated with chronic endurance exercise. The data for blood pressure lowering effects of resistive training are much less compelling, and this area requires additional investigation. However, it appears that resistance training is not associated with chronic elevations in blood pressure. Future studies need to focus on: 1) the relative efficacy of low-, moderate- and high-intensity training on lowering blood pressure; 2) the effect of training on ambulatory blood pressure; 3) targeting of at risk and high responding populations; and 4) the importance of insulinemia, SNS tone and central adiposity in the mechanism of any blood pressure lowering effect of training.

  9. Adaptation of junior orienteers to loads, developing local-regional and special muscular endurance

    Directory of Open Access Journals (Sweden)

    R.Y. Abzalilov

    2017-10-01

    Full Text Available Purpose: complex assessment of junior sport orientation athletes in conditions of concentrated training of local-regional muscular endurance and stroke loads (final part of preparation for competitions. Materials: in the research sport orientation athletes (n=34, age 13-16 years participated. The athletes were divided into tested group (n=17 and group of comparison (n=17. In every group there were 17 boys and girls. The tested group consisted of volunteers, who practiced sport orientation. Comparison group included average distance and steeplechase runners. Results: In system of junior orienteers’ training we found: gender distinctions in carbohydrates and fats consumption (in the ranges of aerobic and anaerobic thresholds; substantial physiological changes in static-kinetic balance (tests with open and closed eyes. Dynamic coefficient of balance in main stance was better in sport orienteers, comparing with runners. Conclusions: it is recommended to fulfill exercises in conditions of stretching, combined with motor actions of speed-power orientation and relaxation.

  10. The Endurance of Family Businesses. A Global Overview

    OpenAIRE

    P., Fernandez Perez; Colli, Andrea

    2013-01-01

    The Endurance of Family Businesses is a collection of essays offering an overview of the importance and resilience of family-controlled large businesses. Much of economic and business history research neglects family businesses, considering them an inefficient form of business organisation. These essays discuss the strengths of family businesses: the ways family firms have managed, financed and governed their corporations, as well as the way in which they structure their relationship with the...

  11. Endurance exercise and gut microbiota: a systematic review

    OpenAIRE

    Fuster-Botella, Dolors

    2017-01-01

    The physiological and biochemical demands of intense exercise elicit both muscle-based and systemic responses. The main adaptations to endurance exercise include the correction of electrolyte imbalance, a decrease in glycogen storage and the increase of oxidative stress, intestinal permeability, muscle damage, and systemic inflammatory response. Adaptations to exercise might be influenced by the gut microbiota, which plays an important role in the production, storage, and expenditure of energ...

  12. Antioxidant supplementation does not alter endurance training adaptation

    DEFF Research Database (Denmark)

    Yfanti, Christina; Åkerström, Thorbjörn; Nielsen, Søren

    2010-01-01

    ) production, which may cause cell damage. However, RONS production may also activate redox sensitive signaling pathways and transcription factors, which subsequently may promote training adaptation. PURPOSE: Our aim was to investigate the effects of combined vitamin C and E supplementation to healthy...... measured. CONCLUSION: Our results suggest that administration of vitamins C and E to individuals with no prior vitamin deficiencies has no effect on physical adaptations to strenuous endurance training....

  13. Endurance exercise training increases peripheral vascular response in human fingers.

    Science.gov (United States)

    Katayama, K; Shimoda, M; Maeda, J; Takemiya, T

    1998-10-01

    The purpose of this study was to clarify whether peripheral vascular response to alteration of transmural pressure is changed by endurance exercise training. The healthy male subjects (training group; n = 6) performed endurance exercise training that consisted of cycle ergometer exercise 5 d.week-1 and 30 min.d-1 for a period of 8 weeks. Changes in the peripheral vascular response to alteration of transmural pressure in the human finger were measured by a differential digital photoplethysmogram (DeltaDPG) and blood pressure during passive movement of the arm to different vertical hand positions relative to heart level. Following 8 weeks of endurance training, percent changes in DeltaDPG from heart level in the training group increased significantly (mean +/- SD, -48.1 +/- 7. 3 to -58.7 +/- 9.3% at the lowered position, 46.1 +/- 13.4 to 84.6 +/- 8.8% at the elevated position, ppressure, also significantly changed in the training group over the 8 weeks (5.6 +/- 1.3 to 2.7 +/- 1.6 mV. V-1.s-1.mmHg-1 at the lowered position, 30.0 +/- 12.4 to 54.4 +/- 18. 9 mV.V-1.s-1.mmHg-1 at the elevated position ). Maximal oxygen uptake (V.O2 max) was significantly increased in the training group. On the other hand, the control group (n = 6) showed no significant changes in all parameters for 8 weeks. Therefore these results suggest that endurance exercise training induces an increase in peripheral vascular response to alteration of transmural pressure in the human finger.

  14. Effects of high intensity training and continuous endurance training on aerobic capacity and body composition in recreationally active runners.

    Science.gov (United States)

    Hottenrott, Kuno; Ludyga, Sebastian; Schulze, Stephan

    2012-01-01

    The aim of the study was to examine the effects of two different training programs (high-intensity-training vs. continuous endurance training) on aerobic power and body composition in recreationally active men and women and to test whether or not participants were able to complete a half marathon after the intervention period. Thirty-four recreational endurance runners were randomly assigned either to a Weekend-Group (WE, n = 17) or an After-Work- Group (AW, n = 17) for a 12 week-intervention period. WE weekly completed 2 h 30 min of continuous endurance running composed of 2 sessions on the weekend. In contrast, AW performed 4 30 min sessions of high intensity training and an additional 30 min endurance run weekly, always after work. During an exhaustive treadmill test aerobic power was measured and heart rate was continuously recorded. Body composition was assessed using bio-impedance. Following the intervention period all subjects took part in a half-marathon. AW significantly improved peak oxygen uptake (VO2 peak) from 36.8 ± 4.5 to 43.6 ± 6.5 [mL.min(-1).kg(-1)], velocity at lactate threshold (VLT) from 9.7 ± 2.2 to 11.7 ± 1.8 [km.h(-1)] and visceral fat from 5.6 ± 2.2 to 4.7 ± 1.9 In WE VO2 peak signifi-cantly increased from 38.8 ± 5.0 to 41.5 ± 6.0 [mL.min(-1).kg(-1)], VLT from 9.9 ± 1.3 to 11.2 ± 1.7 [km.h(-1)] and visceral fat was reduced from 5.7 ± 2.1 to 5.4 ± 1.9 (p marathon with no significant differences in performance (p = 0.63). Short, intensive endurance training sessions of about 30 min are effective in improving aerobic fitness in recreationally active runners. Key pointsContinuous endurance training and high intensity training lead to significant improvements of aerobic capacity and body compositionBoth training methods enable recreationally active runners to finish a half-marathonHigh intensity training is favorable to improve VO2 peak.

  15. Decline in measured glomerular filtration rate is associated with a decrease in endurance, strength, balance and fine motor skills.

    Science.gov (United States)

    Hellberg, Matthias; Höglund, Peter; Svensson, Philippa; Abdulahi, Huda; Clyne, Naomi

    2017-07-01

    Physical performance in chronic kidney disease affects morbidity and mortality. The aim was to find out which measures of physical performance are important in chronic kidney disease (CKD) and if there are associations with declining measured glomerular filtration rate (GFR). Endurance was assessed by 6 min walk test (6-MWT) and stair climbing, muscular endurance by 30 s sit to stand, heel rises and toe lifts, strength by quadriceps- and handgrip-strength, balance by functional reach and Berg's balance scale, and fine motor skills by Moberg's picking-up test. GFR was measured by Iohexol clearance. The study comprised 101 patients with CKD 3b-5 not started dialysis, 40 women and 61 men, with a mean age of 67 ± 13 (range: 22 - 87) years. All measures of physical performance were impaired. A decrease in GFR of 10 mL/min per 1.73 m 2 corresponded to a 35 metre shorter walking distance in the 6-MWT. Multivariable linear regression analysis showed significant relationships between decline in GFR and the 6-MWT (P = 0.04), isometric quadriceps strength left (P = 0.04), balance measured as functional reach (P = 0.02) and fine motor skills in the left hand as measured by Moberg's picking-up test (P = 0.01), respectively, after sex, age, comorbidity and the interaction between sex and age had been taken into account. Endurance, muscular endurance, strength, balance and fine motor skills were impaired in patients with CKD 3b-5. Walking capacity, isometric quadriceps strength, balance, and fine motor skills were associated with declining GFR. The left extremities were more susceptible to GFR, ageing and comorbidities and seem thus to be more sensitive. © 2016 Asian Pacific Society of Nephrology.

  16. Venous hemogasometry of equines finalists in 90 km endurance races

    Directory of Open Access Journals (Sweden)

    Cinthia B.S. Dumont

    2014-06-01

    Full Text Available Front of exercise, the organic systems may suffer water-electrolyte and acid-base imbalances, particularly in the case of blood gases, demonstrating variations from different causes, whether respiratory and/or metabolic. Understanding the physiological adaptations to exercise is essential in the search for the optimum performance. In this way, this study measured the venous blood gases (pO2, pCO2, as well as the oxygen saturation (SatO2 in healthy equines, Arabian horses finalists in 90km endurance races. A total of fourteen Arabian horses were evaluated, nine males and five females, between six and 12 years old, finalists in 90km endurance races. There was a significant reduction in pO2, pCO2 and SatO2 after the exercise, however, the values remained within the normality range, and did not change the athletic performance of the animals, indicating a temporary alteration, assuming thus a character of physiological response to the exercise performed. The equines, finalists in 90 Km endurance races, demonstrated efficient ventilatory process, without any alterations in the athletic performance, being adapted to the type of exercise imposed.

  17. [Endurance capabilities of triathlon competitors with type 1 diabetes mellitus].

    Science.gov (United States)

    Boehncke, S; Poettgen, K; Maser-Gluth, C; Reusch, J; Boehncke, W-H; Badenhoop, K

    2009-04-01

    Treatment of type 1 diabetes mellitus (DM) aims to prevent complications by strictly optimizing blood glucose levels. Although physical exercise is an important part of metabolic control, endurance sports are considered hazardous for patients with type 1 diabetes because of the extreme physiological stress they represent. To further elucidate the metabolic challenge this form of exercise presented we investigated the performance of triathlon competitors with type 1 diabetes. Ten patients (32-61 years) with type 1 diabetes (disease duration 2-35 years) were followed for three years, during which each year they participated in one triathlon long-distance competitions (2.4 miles swimming, 26.2 miles running and 112 miles cycling; Ironman Germany 2005-2007). Glucose, cortisol, aldosterone, renin, thyroid hormones, testosterone, growth hormone and catecholamines were measured in blood and saliva. Five non-diabetic competitors served as controls. The performance equalled those of age-matched healthy athletes. Several participants experienced hyperglycemia early in the bike leg, whereas all of them developed low blood glucose levels during the marathon leg. Basal insulin supply was reduced up to 50 % on race day. Hormone levels in athletes with type 1 DM and healthy controls were similar. Patients with type 1 DM can successfully sustain extreme endurance challenges. Physiological alterations of the metabolic state complicated by type 1 DM can readily be compensated by adapting intensified insulin therapy and nutritional modifications. Thus 1 DM should not be regarded a contraindication to participating in high endurance sports.

  18. Cortical thickness and low insight into symptoms in enduring schizophrenia.

    Science.gov (United States)

    Emami, Seema; Guimond, Synthia; Mallar Chakravarty, M; Lepage, Martin

    2016-01-01

    Poor insight is a common, multidimensional phenomenon in patients with schizophrenia, associated with poorer outcomes and treatment non-adherence. Yet scant research has investigated the neuronal correlates of insight into symptoms (IS), a dimension of insight that may be particularly significant in enduring schizophrenia. Sixty-six patients with enduring schizophrenia (duration >4years) and 33 healthy controls completed MRI scanning and IQ, depression, and anxiety assessments. The Scale to Assess Insight-Expanded (SAI-E) measured insight into patients' four most prominent symptoms and patients were classified into two groups: low IS (0-2; n=33), and high IS (>2; n=33). We evaluated the association between cortical thickness (CT) and insight into symptoms using two methods: (1) a between-patients region-of-interest analysis in the insula, superior temporal gyrus (STG) and frontal lobe; and (2) a whole-brain exploratory regression between patient and controls. Brain regions were segmented using a neuroanatomical atlas and vertex-wise CT analyses were conducted with CIVET, covaried for age and sex. ROI analysis revealed thinner insula cortex in patients with low IS (pinsight-related differences in CT that has been previously unexplored in enduring schizophrenia. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. A new approach to calculating endurance in electric flight and comparing fuel cells and batteries

    International Nuclear Information System (INIS)

    Donateo, Teresa; Ficarella, Antonio; Spedicato, Luigi; Arista, Alessandro; Ferraro, Marco

    2017-01-01

    Highlights: • Gross endurance of an UAV calculated with literature correlations. • Net endurance calculated with an innovative mission-based approach. • Three state-of-the-art battery technologies compared to a PEM fuel cell. • Analysis with different values of energy stored on board. • Effect of powertrain mass and volume of aircraft empty mass and wing area. - Abstract: Electric flight is of increasing interest in order to reduce emissions of pollution and greenhouse gases in the aviation field in particular when the takeoff mass is low, as in the case of lightweight cargo transport or remotely controlled drones. The present investigation addresses two key issues in electric flight, namely the correct calculation of the endurance and the comparison between batteries and fuel cells, with a mission-based approach. As a test case, a light Unmanned Aerial Vehicle (UAV) powered exclusively by a Polymer Electrolyte Membrane fuel cell with a gaseous hydrogen tank was compared with the same aircraft powered by different kinds of Lithium batteries sized to match the energy stored in the hydrogen tank. The mass and the volume of each powertrain were calculated with literature data about existing technologies for propellers, motors, batteries and fuel cells. The empty mass and the wing area of the UAV were amended with the mass of the proposed powertrain to explore the range of application of the proposed technologies. To evaluate the efficiency of the whole powertrain a simulation software was used instead of considering only level flight. This software allowed an in-depth analysis on the efficiency of all sub-systems along the flight. The secondary demand of power for auxiliaries was taken into account along with the propulsive power. The main parameter for the comparison was the endurance but the takeoff performance, the volume of the powertrain and the environmental impact were also taken into account. The battery-based powertrain was found to be the most

  20. Enhancement of Endurance in HfO2-Based CBRAM Device by Introduction of a TaN Diffusion Blocking Layer

    KAUST Repository

    Chand, Umesh

    2017-08-05

    We propose a new method to improve resistive switching properties in HfO2 based CBRAM crossbar structure device by introducing a TaN thin diffusion blocking layer between the Cu top electrode and HfO2 switching layer. The Cu/TaN/HfO2/TiN device structure exhibits high resistance ratio of OFF/ON states without any degradation in switching during endurance test. The improvement in the endurance properties of the Cu/TaN/HfO2/TiN CBRAM device is thus attributed to the relatively low amount of Cu migration into HfO2 switching layer.

  1. A comparison of ultra-endurance cyclists in a qualifying ultra-cycling race for Paris-Brest-Paris and Race Across America-Swiss cycling marathon.

    Science.gov (United States)

    Knechtle, Beat; Wirth, Andrea; Knechtle, Patrizia; Rüst, Christoph Alexander; Rosemann, Thomas

    2012-02-01

    Ultra-endurance events test the adaptation of human physiology to extreme physical and mental demands, high levels of training, motivation, and physical conditioning among participants. To understand basic differences among participants according to the severity of the race, participants in qualifying events for two ultra-endurance cycling races, differing in length and intensity, were compared on measures of anthropometry, training, and support. One race was four times longer, required supporting teams, and racers typically had little sleep, which should lead to the qualifiers being substantially more highly trained than those from the shorter race. The qualifiers in the longer race had greater intensity in training while the qualifiers in the shorter race relied more on training volume. Different strategies and types of training reflected the different demands of the races. Future studies should evaluate personality and motivational differences in ultra-endurance events and between these athletes and athletes in other sports.

  2. Left ventricular atrioventricular plane displacement is preserved with lifelong endurance training and is the main determinant of maximal cardiac output

    DEFF Research Database (Denmark)

    Steding-Ehrenborg, Katarina; Boushel, Robert C; Calbet, José A

    2015-01-01

    subjects (29 ± 4 years) underwent cardiac MR. All subjects underwent maximal exercise testing and for elderly subjects maximal cardiac output during cycling was determined using dye dilution technique. RESULTS: Longitudinal and radial contribution to stroke volume did not differ between groups......BACKGROUND: Age-related decline in cardiac function can be prevented or postponed by lifelong endurance training. However, effects of normal ageing as well as of lifelong endurance exercise on longitudinal and radial contribution to stroke volume are unknown. The aim of this study was to determine...... groups for RVAVPD (P = 0.2). LVAVPD was an independent predictor of maximal cardiac output (R(2 = ) 0.61, P groups. However, how longitudinal pumping...

  3. Effect of the SPARK Program on Physical Activity, Cardiorespiratory Endurance, and Motivation in Middle-School Students.

    Science.gov (United States)

    Fu, You; Gao, Zan; Hannon, James C; Burns, Ryan D; Brusseau, Timothy A

    2016-05-01

    This study aimed to examine the effect of a 9-week SPARK program on physical activity (PA), cardiorespiratory endurance (Progressive Aerobic Cardiovascular Endurance Run; PACER), and motivation in middle-school students. 174 students attended baseline and posttests and change scores computed for each outcome. A MANOVA was employed to examine change score differences using follow-up ANOVA and Bonferroni post hoc tests. MANOVA yielded a significant interaction for Grade × Gender × Group (Wilks's Λ = 0.89, P interactions with perceived competence differences between SPARK grades 6 and 8 (Mean Δ = 0.38, P < .05), Enjoyment differences between SPARK grades 6 and 7 (Mean Δ = 0.67, P < .001), and SPARK grades 6 and 8 (Mean Δ = 0.81, P < .001). Following the intervention, SPARK displayed greater increases on PA and motivation measures in younger students compared with the Traditional program.

  4. The effect on glycaemic control of low-volume high-intensity interval training versus endurance training in individuals with type 2 diabetes.

    Science.gov (United States)

    Winding, Kamilla M; Munch, Gregers W; Iepsen, Ulrik W; Van Hall, Gerrit; Pedersen, Bente K; Mortensen, Stefan P

    2018-05-01

    To evaluate whether high-intensity interval training (HIIT) with a lower time commitment can be as effective as endurance training (END) on glycaemic control, physical fitness and body composition in individuals with type 2 diabetes. A total of 29 individuals with type 2 diabetes were allocated to control (CON; no training), END or HIIT groups. Training groups received 3 training sessions per week consisting of either 40 minutes of cycling at 50% of peak workload (END) or 10 1-minute intervals at 95% of peak workload interspersed with 1 minute of active recovery (HIIT). Glycaemic control (HbA1c, oral glucose tolerance test, 3-hour mixed meal tolerance test with double tracer technique and continuous glucose monitoring [CGM]), lipolysis, VO 2 peak and body composition were evaluated before and after 11 weeks of intervention. Exercise training increased VO 2 peak more in the HIIT group (20% ± 20%) compared with the END group (8% ± 9%) despite lower total energy expenditure and time usage during the training sessions. HIIT decreased whole body and android fat mass compared with the CON group. In addition, visceral fat mass, HbA1c, fasting glucose, postprandial glucose, glycaemic variability and HOMA-IR decreased after HIIT. The reduced postprandial glucose in the HIIT group was driven primarily by a lower rate of exogenous glucose appearance. In the CON group, postprandial lipolysis was augmented over the 11-week control period. Despite a ~45% lower training volume, HIIT resulted in similar or even better improvements in physical fitness, body composition and glycemic control compared to END. HIIT therefore appears to be an important time-efficient treatment for individuals with type 2 diabetes. © 2017 John Wiley & Sons Ltd.

  5. Effects of a Worksite Supervised Adapted Physical Activity Program on Trunk Muscle Endurance, Flexibility, and Pain Sensitivity Among Vineyard Workers.

    Science.gov (United States)

    Balaguier, Romain; Madeleine, Pascal; Rose-Dulcina, Kévin; Vuillerme, Nicolas

    2017-01-01

    In viticulture, the prevalence of low back pain is particularly high among vineyard workers exposed to sustained and awkward postures. One promising setting for low back pain prevention resides in the implementation of workplace physical activity. This nonrandomized pilot study aims at evaluating the effects of a worksite supervised adapted physical activity program among 17 vineyard workers volunteered to enter either an intervention group (n = 10) or a control group (n = 7).The intervention group followed a physical activity program for 8 weeks involving (1) 15 minutes of warm-up every working day and (2) two weekly 1-hour adapted physical activity sessions targeting trunk muscle endurance and flexibility. The control group was advised to continue normal physical activity. Evaluations were carried out at weeks 0, 4, 8, and 12. Physical capacity was assessed using flexibility tests for the trunk, along with trunk muscle flexor and extensor endurance tests. Finally, pain sensitivity was evaluated by assessing pressure pain thresholds over 14 anatomical locations in the low back region. For the intervention group, the endurance of the trunk extensor and flexor significantly increased from baseline to week 8 as well as the pressure pain thresholds. No change was observed for the control group over the same period. These encouraging results in combination with the high adherence rate set interesting foundations for the promotion of worksite supervised adapted physical activity and, most likely, offer a new promising approach to prevent low back pain among vineyard workers.

  6. Endurance training induces structural and morphoquantitative changes in rat vagus nerve

    Directory of Open Access Journals (Sweden)

    Eduardo Pianca

    2015-10-01

    Full Text Available ABSTRACTIntroduction:Many nervous system tissues and cells suffers positive changes when faced to exercise training. However, data on vagus nerve adaptation from exercise-induced study is absent.Objective:To analyze the effect of an endurance training on the vagus nerve morphology of rats.Methods:Wistar rats (6 months of age were divided into two groups: control group (CG, n=8, and aerobic trained group (AT, n=8. AT was submitted to a treadmill training program of five times per week during 12 weeks. The maximum speed stipulated in the training protocol corresponded to 60% of the mean maximum intensity achieved by the group in the test of maximum effort.Results:Twelve weeks of treadmill training resulted in left ventricular hypertrophy in the AT group com-pared to CG. There was a significant increase in the area of both the myelinated and unmyelinated axons, and in the area of myelin sheath with training. The number of neurotubules and neurofilaments in myelinated fibers of aerobic trained group was significantly greater than CG (p≤0.05.Conclusion:Endurance training promoted significant increase in morphometric parameters of the vagus nerve in the same way it affect somatic nerves.

  7. Resting sympatho-vagal balance is related to 10 km running performance in master endurance athletes

    Directory of Open Access Journals (Sweden)

    Angelo Cataldo

    2018-02-01

    Full Text Available Relationships between heart rate recovery after exercise (HRR, baseline heart rate variability measures (HRV, and time to perform a 10Km running trial (t10Km were evaluated in "master" athletes of endurance to assess whether the measured indexes may be useful for monitoring the training status of the athletes. Ten “master” athletes of endurance, aged 40-60 years, were recruited. After baseline measures of HRV, the athletes performed a graded maximal test on treadmill and HRR was measured at 1 and 2 minutes from recovery. Subsequently they performed a 10Km running trial and t10Km was related to HRV and HRR indexes. The time to perform a 10Km running trial was significantly correlated with baseline HRV indexes. No correlation was found between t10Km and HRR. Baseline HRV measures, but not HRR, were significantly correlated with the time of performance on 10km running in “master” athletes. The enhanced parasympathetic function at rest appears to be a condition to a better performance on 10km running. HRV can be simple and useful measurements for monitoring the training stratus of athletes and their physical condition in proximity of a competition.

  8. Plasma treatment of fiber facets for increased (de)mating endurance in physical contact fiber connectors

    Science.gov (United States)

    Van Erps, Jürgen; Voss, Kevin; De Witte, Martijn; Radulescu, Radu; Beri, Stefano; Watté, Jan; Thienpont, Hugo

    2016-04-01

    It is known that cleaving an optical fiber introduces a number of irregularities and defects to the fiber's end-face, such as hackles and shockwaves. These defects can act as failure initiators when stress is applied to the end-face. Given the fiber's small diameter of 125 ffm, a large amount of mechanical stress can be expected to be applied on its end-face during the mating-demating cycle. In addition, a connector in a fiber-to-the-home (FTTH) network can be expected to be mated and demated more than 30 times during its lifetime for purposes such as testing, churning, or provisioning. For this reason, the performance of a connector that displays low optical loss when first installed can dramatically degrade after few mating-demating cycles and catastrophic connector failure due to end-face breakage is likely. We present plasma discharge shaping of cleaved fiber tips to strongly improve the endurance of the fibers to repeated mating-demating cycles. We quantify the dependency of the plasma-induced surface curvature of the fiber tip on the plasma duration and on the position of the fiber tip within the plasma cloud. Finally we present data showing the improved endurance of fibers that are exposed to plasma compared to conventional as-cleaved fibers.

  9. Effects of Hemopure on maximal oxygen uptake and endurance performance in healthy humans.

    Science.gov (United States)

    Ashenden, M J; Schumacher, Y O; Sharpe, K; Varlet-Marie, E; Audran, M

    2007-05-01

    Haemoglobin-based oxygen carriers (HBOCs) such as Hemopure are touted as a tenable substitute for red blood cells and therefore potential doping agents, although the mechanisms of oxygen transport of HBOCs are incompletely understood. We investigated whether infusion of Hemopure increased maximal oxygen uptake (V.O 2max) and endurance performance in healthy subjects. Twelve male subjects performed two 4-minute submaximal exercise bouts equivalent to 60 % and 75 % of V.O (2max) on a cycle ergometer, followed by a ramped incremental protocol to elicit V.O (2max). A crossover design tested the effect of infusing either 30 g (6 subjects) or 45 g (6 subjects) of Hemopure versus a placebo. Under our study conditions, Hemopure did not increase V.O (2max) nor endurance performance. However, the infusion of Hemopure caused a decrease in heart rate of approximately 10 bpm (p=0.009) and an average increase in mean ( approximately 7 mmHg) and diastolic blood pressure ( approximately 8 mmHg) (p=0.046) at submaximal and maximal exercise intensities. Infusion of Hemopure did not bestow the same physiological advantages generally associated with infusion of red blood cells. It is conceivable that under exercise conditions, the hypertensive effects of Hemopure counter the performance-enhancing effect of improved blood oxygen carrying capacity.

  10. Endurance exercise modulates levodopa induced growth hormone release in patients with Parkinson's disease.

    Science.gov (United States)

    Müller, Thomas; Welnic, Jacub; Woitalla, Dirk; Muhlack, Siegfried

    2007-07-11

    Acute levodopa (LD) application and exercise release human growth hormone (GH). An earlier trial showed, that combined stimulus of exercise and LD administration is the best provocative test for GH response in healthy participants. Objective was to show this combined effect of LD application and exercise on GH response and to investigate the impact on LD metabolism in 20 previously treated patients with Parkinson's disease (PD). We measured GH- and LD plasma concentrations following soluble 200 mg LD/50 mg benserazide administration during endurance exercise and rest on two separate consecutive days. GH concentrations significantly increased on both days, but GH release was significantly delayed during rest. LD metabolism was not altered due to exercise in a clinical relevant manner. Exercise induced a significant faster LD stimulated GH release in comparison with the rest condition. We did not find the supposed increase of LD induced GH release by endurance exercise. We assume, that only a limited amount of GH is available for GH release in the anterior pituitary following an acute 200 mg LD administration. GH disposal also depends on growth hormone releasing hormone (GHRH), which is secreted into hypothalamic portal capillaries. During the exercise condition, the resulting higher blood pressure supports blood flow and thus GHRH transport towards the GH producing cells in the pituitary. This might additionally have caused the significant faster GH release during exercise.

  11. Titin is a candidate gene for stroke volume response to endurance training: the HERITAGE Family Study.

    Science.gov (United States)

    Rankinen, Tuomo; Rice, Treva; Boudreau, Anik; Leon, Arthur S; Skinner, James S; Wilmore, Jack H; Rao, D C; Bouchard, Claude

    2003-09-29

    A genome-wide linkage scan for endurance training-induced changes in submaximal exercise stroke volume (DeltaSV50) in the HERITAGE Family Study revealed two chromosomal regions (2q31-q32 and 10p11.2) with at least suggestive evidence of linkage among white families. Here we report a further characterization of the quantitative trait locus (QTL) in chromosome 2q31 and provide evidence that titin (TTN) is likely a candidate gene involved. The original linkage was detected with two markers (D2S335 and D2S1391), and the QTL covered approximately 25 million base pairs (Mb). We added 12 microsatellite markers resulting in an average marker density of one marker per 2.3 Mb. The evidence of linkage increased from P = 0.006 to P = 0.0002 and 0.00002 in the multi- and single-point analyses, respectively. The strongest evidence of linkage was seen with two markers in and near the TTN gene. Transmission/disequilibrium test (TDT) with the same marker set provided evidence for association with one of the TTN markers (D2S385; P = 0.004). TTN is a major contributor to the elasticity of cardiomyocytes and a key regulator of the Frank-Starling mechanism. Since TTN is the largest gene in the human genome, the challenge is to identify the DNA sequence variants contributing to the interindividual differences in cardiac adaptation to endurance training.

  12. Effect of Endurance Training on Physical Capacity and Anthropometry of Cardiac Patients

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Nikou

    2010-01-01

    Full Text Available Objective: The aim of this study was to measure of cardiac rehabilitation program (Endurance & Resistance training effect on physical functioning as well as its exact effect on lipid profile and fasting blood sugar of cardiovascular patients. Materials & Methods: In this quasi experimental and interventional study 20 patients who arrived to phase II cardiac rehabilitation after their first cardiovascular accident were selected conveniently and participated in this prospective study. Anthropometrics' measurements, FBS and blood lipid, 6–MWT were performed at the beginning and at the end of 8 weeks program (3 days per week for 24 sessions. Data were analyzed by Paired T test. Results: Except for low–density lipoprotein (LDL (P=0.087 and FBS (P=0.072, all other biochemical indices [total cholesterol (TC (P=0.019, high–density lipoprotein (HDL (P=0.019, and triglyceride (TG (P=0.009], functional capacity (6MWT (P<0.001 and measurment of rate pressure product with Borg scale (P=0.008, and also obesity indices including weight (P=0.031 and subcutaneus fat (P=0.017 had significant response to cardiac rehabilitation program (CRP. Conclusion: These results support the benefits of cardiac rehabilitation program such as endurance and resistance training to reduce overall risk in obese patients with coronary heart disease, and increase physical capacity.

  13. Homogenous stretching or detachment faulting? Which process is primarily extending the Aegean crust

    Science.gov (United States)

    Kumerics, C.; Ring, U.

    2003-04-01

    In extending orogens like the Aegean Sea of Greece and the Basin-and-Range province of the western United States, knowledge of rates of tectonic processes are important for understanding which process is primarily extending the crust. Platt et al. (1998) proposed that homogeneous stretching of the lithosphere (i.e. vertical ductile thinning associated with a subhorizontal foliation) at rates of 4-5 km Myr-1 is the dominant process that formed the Alboran Sea in the western Mediterranean. The Aegean Sea in the eastern Mediterranean is well-known for its low-angle normal faults (detachments) (Lister et al., 1984; Lister &Forster, 1996) suggesting that detachment faulting may have been the primary agent achieving ~>250 km (McKenzie, 1978) of extension since the Miocene. Ring et al. (2003) provided evidence for a very fast-slipping detachment on the islands of Syros and Tinos in the western Cyclades, which suggests that normal faulting was the dominant tectonic process that formed the Aegean Sea. However, most extensional detachments in the Aegean do not allow to quantify the amount of vertical ductile thinning associated with extension and therefore a full evaluation of the significance of vertical ductile thinning is not possible. On the Island of Ikaria in the eastern Aegean Sea, a subhorizontal extensional ductile shear zone is well exposed. We studied this shear zone in detail to quantify the amount of vertical ductile thinning associated with extension. Numerous studies have shown that natural shear zones usually deviate significantly from progressive simple shear and are characterized by pronounced shortening perpendicular to the shear zone. Numerous deformed pegmatitic veins in this shear zone on Ikaria allow the reconstruction of deformation and flow parameters (Passchier, 1990), which are necessary for quantifying the amount of vertical ductile thinning in the shear zone. Furthermore, a flow-path and finite-strain study in a syn-tectonic granite, which

  14. NOS3 Glu298Asp genotype and blood pressure response to endurance training: the HERITAGE family study.

    Science.gov (United States)

    Rankinen, T; Rice, T; Pérusse, L; Chagnon, Y C; Gagnon, J; Leon, A S; Skinner, J S; Wilmore, J H; Rao, D C; Bouchard, C

    2000-11-01

    Endothelium-dependent vasodilation is a mechanism that may affect blood pressure response to endurance training. Because NO plays a central role in this process, the endothelial NO synthase gene is a good candidate for the regulation of exercise blood pressure. We investigated the associations between an endothelial NO synthase gene polymorphism (Glu298Asp) and endurance training-induced changes in resting and submaximal exercise blood pressure in 471 white subjects of the HERITAGE Family Study. Two submaximal exercise tests at 50 W were conducted both before and after a 20-week endurance training program. Steady-state exercise blood pressure was measured twice in each test with an automated unit. The Glu298Asp polymorphism was typed with a PCR-based method and digestion with BAN:II. Both systolic and diastolic blood pressure at 50 W decreased in response to the training program, whereas resting blood pressure remained unchanged. The decrease in diastolic blood pressure at 50 W was greater (P=0.0005, adjusted for age, gender, baseline body mass index, and baseline diastolic blood pressure at 50 W) in the Glu/Glu homozygotes (4.4 [SEM 0.4] mm Hg, n=187) than in the heterozygotes (3.1 [0.4] mm Hg, n=213) and the Asp/Asp homozygotes (1.3 [0.7] mm Hg, n=71). The genotype accounted for 2.3% of the variance in diastolic blood pressure at 50 W training response. Both the Glu298 homozygotes and the heterozygotes had a greater (P=0.013) training-induced reduction in rate-pressure product at 50 W than the Asp298 homozygotes. These data suggest that DNA sequence variation in the endothelial NO synthase gene locus is associated with the endurance training-induced decreases in submaximal exercise diastolic blood pressure and rate-pressure product in sedentary normotensive white subjects.

  15. Effects of a concurrent strength and endurance training on running performance and running economy in recreational marathon runners.

    Science.gov (United States)

    Ferrauti, Alexander; Bergermann, Matthias; Fernandez-Fernandez, Jaime

    2010-10-01

    The purpose of this study was to investigate the effects of a concurrent strength and endurance training program on running performance and running economy of middle-aged runners during their marathon preparation. Twenty-two (8 women and 14 men) recreational runners (mean ± SD: age 40.0 ± 11.7 years; body mass index 22.6 ± 2.1 kg·m⁻²) were separated into 2 groups (n = 11; combined endurance running and strength training program [ES]: 9 men, 2 women and endurance running [E]: 7 men, and 4 women). Both completed an 8-week intervention period that consisted of either endurance training (E: 276 ± 108 minute running per week) or a combined endurance and strength training program (ES: 240 ± 121-minute running plus 2 strength training sessions per week [120 minutes]). Strength training was focused on trunk (strength endurance program) and leg muscles (high-intensity program). Before and after the intervention, subjects completed an incremental treadmill run and maximal isometric strength tests. The initial values for VO2peak (ES: 52.0 ± 6.1 vs. E: 51.1 ± 7.5 ml·kg⁻¹·min⁻¹) and anaerobic threshold (ES: 3.5 ± 0.4 vs. E: 3.4 ± 0.5 m·s⁻¹) were identical in both groups. A significant time × intervention effect was found for maximal isometric force of knee extension (ES: from 4.6 ± 1.4 to 6.2 ± 1.0 N·kg⁻¹, p marathon running velocities (2.4 and 2.8 m·s⁻¹) and submaximal blood lactate thresholds (2.0, 3.0, and 4.0 mmol·L⁻¹). Stride length and stride frequency also remained unchanged. The results suggest no benefits of an 8-week concurrent strength training for running economy and coordination of recreational marathon runners despite a clear improvement in leg strength, maybe because of an insufficient sample size or a short intervention period.

  16. The effect of repeated periods of speed endurance training on performance, running economy and muscle adaptations

    DEFF Research Database (Denmark)

    Skovgaard, Casper; Almquist, Nicki Winfield; Bangsbo, Jens

    2018-01-01

    sessions during two 40-day periods (P1 and P2) separated by ~80 days of habitual training. Before and after both P1 and P2, subjects completed an incremental test to exhaustion to determine VO2 -max and a repeated running test at 90% vVO2 -max to exhaustion (RRT) to determine short-term endurance capacity......, with no change in P1. No changes in muscle expression of Na(+) ,K(+) -ATPase α1, α2 and β1, NHE1, SERCA1 and SERCA2, actin and CamKII were found during neither P1 nor P2. Thus, the present study demonstrates that a second period of intense training leads to improved short-term performance and further improved RE...

  17. Heat sensitive persons with multiple sclerosis are more tolerant to resistance exercise than to endurance exercise

    DEFF Research Database (Denmark)

    Skjerbæk, Anders G; Møller, Andreas Buch; Jensen, Ellen

    2012-01-01

    BACKGROUND: Heat sensitivity (HS) is reported by 58% of all persons with multiple sclerosis (MS), causing symptom exacerbation possibly limiting exercise participation. OBJECTIVE: The purpose of this study was to test the hypotheses that (a) a relationship between exercise-induced changes in core...... randomly completed a session of RE and EE, or EE and RE, respectively. Testing was conducted pre, post and one hour after exercise and consisted of Visual Analogue Scale (VAS) scoring (fatigue, spasticity, pain, strength, walking and balance), the 5-time sit-to-stand (5STS), the Multiple Sclerosis......-temperature (C(temp)) and changes in symptom intensity exists, and (b) that resistance exercise (RE), as a consequence of a minor increase in core temperature, will induce a lesser worsening of symptoms than endurance exercise (EE) in HS persons with MS. METHODS: On two separate days, 16 HS persons with MS...

  18. The power of habits : Unhealthy snacking behaviour is primarily predicted by habit strength

    NARCIS (Netherlands)

    Verhoeven, A.A.C.; Adriaanse, M.A.; Evers, C.; de Ridder, D.T.D.

    2012-01-01

    Objective. Although increasing evidence shows the importance of habits in explaining health behaviour, many studies still rely solely on predictors that emphasize the role of conscious intentions. The present study was designed to test the importance of habit strength in explaining unhealthy

  19. Effects of protein in combination with carbohydrate supplements on acute or repeat endurance exercise performance: a systematic review.

    Science.gov (United States)

    McLellan, Tom M; Pasiakos, Stefan M; Lieberman, Harris R

    2014-04-01

    Protein supplements are consumed frequently by athletes and recreationally active adults for various reasons, including improved exercise performance and recovery after exercise. Yet, far too often, the decision to purchase and consume protein supplements is based on marketing claims rather than available evidence-based research. The purpose of this review was to provide a systematic and comprehensive analysis of the literature that tested the hypothesis that protein supplements, when combined with carbohydrate, directly enhance endurance performance by sparing muscle glycogen during exercise and increasing the rate of glycogen restoration during recovery. The analysis was used to create evidence statements based on an accepted strength of recommendation taxonomy. English language articles were searched with PubMed and Google Scholar using protein and supplements together with performance, exercise, competition, and muscle, alone or in combination as keywords. Additional articles were retrieved from reference lists found in these papers. Inclusion criteria specified recruiting healthy active adults less than 50 years of age and evaluating the effects of protein supplements in combination with carbohydrate on endurance performance metrics such as time-to-exhaustion, time-trial, or total power output during sprint intervals. The literature search identified 28 articles, of which 26 incorporated test metrics that permitted exclusive categorization into one of the following sections: ingestion during an acute bout of exercise (n = 11) and ingestion during and after exercise to affect subsequent endurance performance (n = 15). The remaining two articles contained performance metrics that spanned both categories. All papers were read in detail and searched for experimental design confounders such as energy content of the supplements, dietary control, use of trained or untrained participants, number of subjects recruited, direct measures of muscle glycogen utilization and

  20. Analysis of survival for patients with chronic kidney disease primarily related to renal cancer surgery.

    Science.gov (United States)

    Wu, Jitao; Suk-Ouichai, Chalairat; Dong, Wen; Antonio, Elvis Caraballo; Derweesh, Ithaar H; Lane, Brian R; Demirjian, Sevag; Li, Jianbo; Campbell, Steven C

    2018-01-01

    To evaluate predictors of long-term survival for patients with chronic kidney disease primarily due to surgery (CKD-S). Patients with CKD-S have generally good survival that approximates patients who do not have CKD even after renal cancer surgery (RCS), yet there may be heterogeneity within this cohort. From 1997 to 2008, 4 246 patients underwent RCS at our centre. The median (interquartile range [IQR]) follow-up was 9.4 (7.3-11.0) years. New baseline glomerular filtration rate (GFR) was defined as highest GFR between nadir and 6 weeks after RCS. We retrospectively evaluated three cohorts: no-CKD (new baseline GFR of ≥60 mL/min/1.73 m 2 ); CKD-S (new baseline GFR of cancer-related survival (NRCRS) for the CKD-S cohort. Kaplan-Meier analysis assessed the longitudinal impact of new baseline GFR (45-60 mL/min/1.73 m 2 vs <45 mL/min/1.73 m 2 ) and Cox regression evaluated relative impact of preoperative GFR, new baseline GFR, and relevant demographics/comorbidities. Of the 4 246 patients who underwent RCS, 931 had CKD-S and 1 113 had CKD-M/S, whilst 2 202 had no-CKD even after RCS. Partial/radical nephrectomy (PN/RN) was performed in 54%/46% of the patients, respectively. For CKD-S, 641 patients had a new baseline GFR of 45-60 mL/min/1.73 m 2 and 290 had a new baseline GFR of <45 mL/min/1.73 m 2 . Kaplan-Meier analysis showed significantly reduced NRCRS for patients with CKD-S with a GFR of <45 mL/min/1.73 m 2 compared to those with no-CKD or CKD-S with a GFR of 45-60 mL/min/1.73 m 2 (both P ≤ 0.004), and competing risk analysis confirmed this (P < 0.001). Age, gender, heart disease, and new baseline GFR were all associated independently with NRCRS for patients with CKD-S (all P ≤ 0.02). Our data suggest that CKD-S is heterogeneous, and patients with a reduced new baseline GFR have compromised survival, particularly if <45 mL/min/1.73 m 2 . Our findings may have implications regarding choice of PN/RN in patients at risk of developing

  1. CAFFEINE INTAKE ENHANCES ENDURANCE PERFORMANCE IN SUB-ELITE BUT NOT IN ELITE ATHLETES

    Directory of Open Access Journals (Sweden)

    Ondřej Smolka

    2015-01-01

    Full Text Available The aim of our contribution is to evaluate the influence of caffeine (CAF ingestion on maximal power output (MPO during endurance performance. Two groups of men – 10 sub-elite cyclists and 8 elite cyclists completed a randomized, crossover, double-blind study. Over the course of three days participants completed three identical experimental tests (60min cycling time trial on 70 % VO2max followed by test to exhaustion. Three experimental meals - a combination of 500ml water, a gel supplement and a specific dose of CAF: a placebo (PLA, no caffeine, CAF2 (2 mg / kg body weight (BW and CAF7 (7 mg / kg BW were administered 45min prior to the start of the experimental tests. Subjective RPE values were determined using the Borg 20-category scale. The results show significant differences between MPOPLA and MPOCAF7 and between MPOCAF2 and MPOCAF7 with p = 0.018 and p = 0.019, respectively, in the sub-elite cyclists group only. The mean MPO during experimental test in sub-elite cyclists, but not in elite cyclists, was significantly enhanced following caffeine ingestion (p = 0.05. These findings indicate that caffeine intake at recommended levels is not associated with improved performance in a professional level cyclist. The results of the comparison of the experimental situations using the Borg scale are not persuasive. We found a significant difference (0.008356 between the PLA and CAF2 experimental measurements (p < 0.05. The level of substantive significance was assessed using Cohen’s coefficient effect and only a small “size of effect” (0.19 was found. It is therefore not possible to determine whether the Borg scale might be used to define the effects of caffeine ingestion on endurance performance, due to the multifactorial effects of caffeine.

  2. Effects of oral sodium supplementation on indices of thermoregulation in trained, endurance athletes.

    Science.gov (United States)

    Earhart, Elizabeth L; Weiss, Edward P; Rahman, Rabia; Kelly, Patrick V

    2015-03-01

    Guidelines recommend the consumption of sodium during exercise to replace losses in sweat; however, the effects of sodium on thermoregulation are less clear. To determine the effects of high-dose sodium supplementation on indices of thermoregulation and related outcomes, 11 endurance athletes participated in a double-blind, randomized-sequence, crossover study in which they underwent 2-hrs of endurance exercise at 60% heart rate reserve with 1800 mg of sodium supplementation (SS) during one trial and placebo (PL) during the other trial. A progressive intensity time-to-exhaustion test was performed after the 2-hr steady state exercise as an assessment of exercise performance. Sweat rate was calculated from changes in body weight, accounting for fluid intake and urinary losses. Ratings of perceived exertion (RPE) and heat stress were assessed using verbal numeric scales. Cardiovascular drift was determined from the rise in HR during the 2-hr steady state exercise test. Skin temperature was measured with an infrared thermometer. Dehydration occurred in both SS and PL trials, as evidenced by substantial weight loss (2.03 ± 0.43% and 2.27 ± 0.70%, respectively; p = 0.261 between trials). Sweat rate was 1015.53 ± 239.10 ml·hr(-1) during the SS trial and 1053.60±278.24 ml/hr during the PL trial, with no difference between trials (p = 0.459). Heat stress ratings indicated moderate heat stress ("warm/hot" ratings) but were not different between trials (p = 0.825). Time to exhaustion during the SS trial was 6.88 ± 3.88 minutes and during the PL trial averaged 6.96 ± 3.61 minutes, but did not differ between trials (p = 0.919). Cardiovascular drift, skin temperature, and RPE did not differ between trials (all p > 0.05). High-dose sodium supplementation does not appear to impact thermoregulation, cardiovascular drift, or physical performance in trained, endurance athletes. However, in light of the possibility that high sodium intakes might have other adverse effects

  3. Effect of different protocols of caffeine intake on metabolism and endurance performance.

    Science.gov (United States)

    Cox, Gregory R; Desbrow, Ben; Montgomery, Paul G; Anderson, Megan E; Bruce, Clinton R; Macrides, Theodore A; Martin, David T; Moquin, Angela; Roberts, Alan; Hawley, John A; Burke, Louise M

    2002-09-01

    Competitive athletes completed two studies of 2-h steady-state (SS) cycling at 70% peak O(2) uptake followed by 7 kJ/kg time trial (TT) with carbohydrate (CHO) intake before (2 g/kg) and during (6% CHO drink) exercise. In Study A, 12 subjects received either 6 mg/kg caffeine 1 h preexercise (Precaf), 6 x 1 mg/kg caffeine every 20 min throughout SS (Durcaf), 2 x 5 ml/kg Coca-Cola between 100 and 120 min SS and during TT (Coke), or placebo. Improvements in TT were as follows: Precaf, 3.4% (0.2-6.5%, 95% confidence interval); Durcaf, 3.1% (-0.1-6.5%); and Coke, 3.1% (-0.2-6.2%). In Study B, eight subjects received 3 x 5 ml/kg of different cola drinks during the last 40 min of SS and TT: decaffeinated, 6% CHO (control); caffeinated, 6% CHO; decaffeinated, 11% CHO; and caffeinated, 11% CHO (Coke). Coke enhanced TT by 3.3% (0.8-5.9%), with all trials showing 2.2% TT enhancement (0.5-3.8%; P < 0.05) due to caffeine. Overall, 1) 6 mg/kg caffeine enhanced TT performance independent of timing of intake and 2) replacing sports drink with Coca-Cola during the latter stages of exercise was equally effective in enhancing endurance performance, primarily due to low intake of caffeine (approximately 1.5 mg/kg).

  4. The effects of elevated pain inhibition on endurance exercise performance

    Directory of Open Access Journals (Sweden)

    Andrew Flood

    2017-03-01

    Full Text Available Background The ergogenic effects of analgesic substances suggest that pain perception is an important regulator of work-rate during fatiguing exercise. Recent research has shown that endogenous inhibitory responses, which act to attenuate nociceptive input and reduce perceived pain, can be increased following transcranial direct current stimulation of the hand motor cortex. Using high-definition transcranial direct current stimulation (HD-tDCS; 2 mA, 20 min, the current study aimed to examine the effects of elevated pain inhibitory capacity on endurance exercise performance. It was hypothesised that HD-tDCS would enhance the efficiency of the endogenous pain inhibitory response and improve endurance exercise performance. Methods Twelve healthy males between 18 and 40 years of age (M = 24.42 ± 3.85 were recruited for participation. Endogenous pain inhibitory capacity and exercise performance were assessed before and after both active and sham (placebo stimulation. The conditioned pain modulation protocol was used for the measurement of pain inhibition. Exercise performance assessment consisted of both maximal voluntary contraction (MVC and submaximal muscular endurance performance trials using isometric contractions of the non-dominant leg extensors. Results Active HD-tDCS (pre-tDCS, −.32 ± 1.33 kg; post-tDCS, −1.23 ± 1.21 kg significantly increased pain inhibitory responses relative to the effects of sham HD-tDCS (pre-tDCS, −.91 ± .92 kg; post-tDCS, −.26 ± .92 kg; p = .046. Irrespective of condition, peak MVC force and muscular endurance was reduced from pre- to post-stimulation. HD-tDCS did not significantly influence this reduction in maximal force (active: pre-tDCS, 264.89 ± 66.87 Nm; post-tDCS, 236.33 ± 66.51 Nm; sham: pre-tDCS, 249.25 ± 88.56 Nm; post-tDCS, 239.63 ± 67.53 Nm or muscular endurance (active: pre-tDCS, 104.65 ± 42.36 s; post-tDCS, 93.07 ± 33.73 s; sham: pre-tDCS, 123.42 ± 72.48 s; post

  5. Individual Endurance Training Prescription with Heart Rate Variability.

    Science.gov (United States)

    Vesterinen, Ville; Nummela, Ari; Heikura, Ida; Laine, Tanja; Hynynen, Esa; Botella, Javier; Häkkinen, Keijo

    2016-07-01

    Measures of HR variability (HRV) have shown potential to be of use in training prescription. The aim of this study was to investigate the effectiveness of using HRV in endurance training prescription. Forty recreational endurance runners were divided into the HRV-guided experimental training group (EXP) and traditional predefined training group (TRAD). After a 4-wk preparation training period, TRAD trained according to a predefined training program including two to three moderate- (MOD) and high-intensity training (HIT) sessions per week during an 8-wk intensive training period. The timing of MOD and HIT sessions in EXP was based on HRV, measured every morning. The MOD/HIT session was programmed if HRV was within an individually determined smallest worthwhile change. Otherwise, low-intensity training was performed. Maximal oxygen consumption (V˙O2max) and 3000-m running performance (RS3000m) were measured before and after both training periods. The number of MOD and HIT sessions was significantly lower (P = 0.021, effect size = 0.98) in EXP (13.2 ± 6.0 sessions) compared with TRAD (17.7 ± 2.5 sessions). No other differences in training were found between the groups. RS3000m improved in EXP (2.1% ± 2.0%, P = 0.004) but not in TRAD (1.1% ± 2.7%, P = 0.118) during the intensive training period. A small between-group difference (effect size = 0.42) was found in the change in RS3000m. V˙O2max improved in both groups (EXP: 3.7% ± 4.6%, P = 0.027; TRAD: 5.0% ± 5.2%, P = 0.002). The results of the present study suggest the potential of resting HRV to prescribe endurance training by individualizing the timing of vigorous training sessions.

  6. Measurement of quadriceps endurance by fNIRS

    Science.gov (United States)

    Erdem, Devrim; Şayli, Ömer; Karahan, Mustafa; Akin, A.

    2006-02-01

    In this paper, the changes in muscle deoxygenation trends during a sustained isometric quadriceps (chair squat/half squat) endurance exercise were evaluated among twelve male subjects and the relationship between muscle oxygenation and endurance times was investigated by means of functional near-infrared spectroscopy (fNIRS). Neuromuscular activation and predictions of muscle performance decrements during extended fatiguing task was investigated by means of surface electromyography (sEMG). The results of the study showed that in the subjects who maintained exercise longer than five minutes (group 1), mean Hb recovery time (33 [sec.]) was 37.4% less than the others (group 2, 52.7 [sec.]). Also mean HbO II decline amplitude (2.53 [a.u.] in group 1 and 2.07 [a.u.] in group 2) and oxy decline amplitude (8.4 [a.u.] in group 1 and 3.04 [a.u.] in group 2) in the beginning of squat exercise are found to be 22.6% and 176.9% bigger in these group. For the EMG parameters, mean slope of MNF and MDF decline are found to be 57.5% and 42.2% bigger in magnitude in group 2 which indicates higher degree of decrement in mean and median frequencies although their mean squat duration time is less. This indicates higher index of fatigue for this group. It is concluded that training leads to altered oxygenation and oxygen extraction capability in the exercising muscle and investigated fNIRS parameters could be used for endurance evaluation.

  7. Speed endurance training is a powerful stimulus for physiological adaptations and performance improvements of athletes

    DEFF Research Database (Denmark)

    Iaia, F. M.; Bangsbo, Jens

    2010-01-01

    the oxidative capacity and improve intense short-duration/repeated high-intensity exercise performance lasting 30 s to 4 min, as it occurs in a number of sports. When combined with a basic volume of training including some aerobic high-intensity sessions, speed endurance training is also useful in enhancing......The present article reviews the physiological and performance effects of speed endurance training consisting of exercise bouts at near maximal intensities in already trained subjects. Despite a reduction in training volume, speed endurance training of endurance-trained athletes can maintain...... performance during longer events, e.g. 40 K cycling and 10 K running. Athletes in team sports involving intense exercise actions and endurance aspects can also benefit from performing speed endurance training. These improvements don't appear to depend on changes in maximum oxygen uptake (VO2max), muscle...

  8. A structural equation model of the relationship between muscle strength, balance performance, walking endurance and community integration in stroke survivors.

    Directory of Open Access Journals (Sweden)

    P W H Kwong

    Full Text Available To use structural equation modelling (SEM to determine (1 the direct and indirect associations of strength of paretic lower limb muscles with the level of community integration, and (2 the direct association of walking endurance and balance performance with the level of community integration in community-dwelling stroke survivors.In this cross-sectional study of 105 stroke survivors, the Subjective Index of Physical and Social Outcome (SIPSO was used to measure the level of community integration. Lower-limb strength measures included isometric paretic ankle strength and isokinetic paretic knee peak torque. The Berg Balance Scale (BBS and the 6-minute walk test (6MWT were used to evaluate balance performance and walking endurance, respectively.SEM revealed that the distance walked on the 6MWT had the strongest direct association with the SIPSO score (β = 0.41, p <0.001. An increase of one standard deviation in the 6MWT distance resulted in an increase of 0.41 standard deviations in the SIPSO score. Moreover, dorsiflexion strength (β = 0.18, p = 0.044 and the BBS score (β = 0.21, p = 0.021 had direct associations with the SIPSO score.The results of the proposed model suggest that rehabilitation training of community-dwelling stroke survivors could focus on walking endurance, balance performance and dorsiflexor muscle strengthening if the aim is to augment the level of community integration.

  9. Effects of plyometric training and creatine supplementation on maximal-intensity exercise and endurance in female soccer players.

    Science.gov (United States)

    Ramírez-Campillo, Rodrigo; González-Jurado, José Antonio; Martínez, Cristian; Nakamura, Fábio Yuzo; Peñailillo, Luis; Meylan, Cesar M P; Caniuqueo, Alexis; Cañas-Jamet, Rodrigo; Moran, Jason; Alonso-Martínez, Alicia M; Izquierdo, Mikel

    2016-08-01

    To investigate the effects of a six-week plyometric training and creatine supplementation intervention on maximal-intensity and endurance performance in female soccer players during in-season training. Randomized, double-blind, placebo-controlled trial. Young (age 22.9±2.5y) female players with similar training load and competitive background were assigned to a plyometric training group receiving placebo (PLACEBO, n=10), a plyometric training group receiving creatine supplementation (CREATINE, n=10) or a control group receiving placebo without following a plyometric program (CONTROL, n=10). Athletes were evaluated for jumping, maximal and repeated sprinting, endurance and change-of-direction speed performance before and after six weeks of training. After intervention the CONTROL group did not change, whereas both plyometric training groups improved jumps (ES=0.25-0.49), sprint (ES=0.35-0.41), repeated sprinting (ES=0.48-0.55), endurance (ES=0.32-0.34) and change-of-direction speed performance (ES=0.46-0.55). However, the CREATINE group improved more in the jumps and repeated sprinting performance tests than the CONTROL and the PLACEBO groups. Adaptations to plyometric training may be enhanced with creatine supplementation. Copyright © 2015 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  10. Effects of plyometric training on maximal-intensity exercise and endurance in male and female soccer players.

    Science.gov (United States)

    Ramírez-Campillo, Rodrigo; Vergara-Pedreros, Marcelo; Henríquez-Olguín, Carlos; Martínez-Salazar, Cristian; Alvarez, Cristian; Nakamura, Fábio Yuzo; De La Fuente, Carlos I; Caniuqueo, Alexis; Alonso-Martinez, Alicia M; Izquierdo, Mikel

    2016-01-01

    In a randomised controlled trial design, effects of 6 weeks of plyometric training on maximal-intensity exercise and endurance performance were compared in male and female soccer players. Young (age 21.1 ± 2.7 years) players with similar training load and competitive background were assigned to training (women, n = 19; men, n = 21) and control (women, n = 19; men, n = 21) groups. Players were evaluated for lower- and upper-body maximal-intensity exercise, 30 m sprint, change of direction speed and endurance performance before and after 6 weeks of training. After intervention, the control groups did not change, whereas both training groups improved jumps (effect size (ES) = 0.35-1.76), throwing (ES = 0.62-0.78), sprint (ES = 0.86-1.44), change of direction speed (ES = 0.46-0.85) and endurance performance (ES = 0.42-0.62). There were no differences in performance improvements between the plyometric training groups. Both plyometric groups improved more in all performance tests than the controls. The results suggest that adaptations to plyometric training do not differ between men and women.

  11. Was the Conconi test validated by sporting success, expert opinion ...

    African Journals Online (AJOL)

    Was the Conconi test validated by sporting success, expert opinion or good science? ... Open Access DOWNLOAD FULL TEXT ... Despite scientific evidence to the contrary, a popular incremental field test for endurance athletes (Conconi Test) ...

  12. Diazo groups endure metabolism and enable chemoselectivity in cellulo.

    Science.gov (United States)

    Andersen, Kristen A; Aronoff, Matthew R; McGrath, Nicholas A; Raines, Ronald T

    2015-02-25

    We introduce a stabilized diazo group as a reporter for chemical biology. ManDiaz, which is a diazo derivative of N-acetylmannosamine, is found to endure cellular metabolism and label the surface of a mammalian cell. There its diazo group can undergo a 1,3-dipolar cycloaddition with a strained alkyne, providing a signal comparable to that from the azido congener, ManNAz. The chemoselectivity of diazo and alkynyl groups enables dual labeling of cells that is not possible with azido and alkynyl groups. Thus, the diazo group, which is approximately half the size of an azido group, provides unique opportunities for orthogonal labeling of cellular components.

  13. Supplementation strategies for gastrointestinal distress in endurance athletes

    Directory of Open Access Journals (Sweden)

    Vivian Ximeno Duarte

    2015-10-01

    Full Text Available The prevalence of gastrointestinal symptoms in the endurance athlete is about 25% to 70%. Even though it is recognized that the etiology of exercise-induced gastrointestinal distress is multifactorial, blood flow redistribution during physical activity and therefore gastrointestinal ischemia is often acknowledged as the main pathophysiology mechanism for the onset of symptoms. This review will provide an overview to the recent research on gastrointestinal function during strenuous exercise. In addition, we consider different nutritional interventions that could be evaluated for preventive or treatment interventions founding that ever though there is some research in the area, the scientific evidence does not support its use in athlete population.

  14. An Enduring Dialogue between Computational and Empirical Vision.

    Science.gov (United States)

    Martinez-Conde, Susana; Macknik, Stephen L; Heeger, David J

    2018-04-01

    In the late 1970s, key discoveries in neurophysiology, psychophysics, computer vision, and image processing had reached a tipping point that would shape visual science for decades to come. David Marr and Ellen Hildreth's 'Theory of edge detection', published in 1980, set out to integrate the newly available wealth of data from behavioral, physiological, and computational approaches in a unifying theory. Although their work had wide and enduring ramifications, their most important contribution may have been to consolidate the foundations of the ongoing dialogue between theoretical and empirical vision science. Copyright © 2018 Elsevier Ltd. All rights reserved.

  15. No Superior Adaptations to Carbohydrate Periodization in Elite Endurance Athletes

    DEFF Research Database (Denmark)

    Gejl, Kasper Degn; Thams, Line Bork; Hansen, Mette

    2017-01-01

    endurance training, while matched and randomized into two groups training with (Low) or without (High) carbohydrate (CHO) manipulation three days a week. The CHO manipulation days consisted of a 1-hr high intensity bike session in the morning, recovery for 7 hrs while consuming isocaloric diets containing...... either high CHO (414±2.4 g) or low CHO (79.5±1.0 g), and a 2-hr moderate bike session in the afternoon with or without CHO. VO2max, maximal fat oxidation and power output during a 30-min time trial (TT) were determined before and after the training period. The TT was undertaken after 90 mins...

  16. Materiality and the Enduring Aspects of Organisational Identities

    DEFF Research Database (Denmark)

    Backer, Lise

    This article contributes to the emerging body of work in organisational theory that seeks to include materiality in conceptualising processes of organizing (e.g. Law, 1994; Doolin, 2003; Czarniawska and Gustavsson, 2004; Dale, 2005). Using the four largest multinational oil companies' green...... transition towards renewable energies as a case the article integrates material aspects into the theory on the narration of organisational identities. Following Czarniawska (1997) the concept of organisational identity is viewed as an evolving organisational narrative. Following Law (1994....... The article concludes to that end that both social and material aspects add to the endurance of organisational identities....

  17. The power of habits: unhealthy snacking behaviour is primarily predicted by habit strength.

    Science.gov (United States)

    Verhoeven, Aukje A C; Adriaanse, Marieke A; Evers, Catharine; de Ridder, Denise T D

    2012-11-01

    Although increasing evidence shows the importance of habits in explaining health behaviour, many studies still rely solely on predictors that emphasize the role of conscious intentions. The present study was designed to test the importance of habit strength in explaining unhealthy snacking behaviour in a large representative community sample (N= 1,103). To test our hypothesis that habits are crucial when explaining unhealthy snacking behaviour, their role was compared to the 'Power of Food', a related construct that addresses sensitivity to food cues in the environment. Moreover, the relation between Power of Food and unhealthy snacking habits was assessed. A prospective design was used to determine the impact of habits in relation to intention, Power of Food and a number of demographic variables. One month after filling out the questionnaire, including measures of habit strength and Power of Food, participants reported their unhealthy snacking behaviour by means of a 7-day snack diary. Results showed that habit strength was the most important predictor, outperforming all other variables in explaining unhealthy snack intake. The findings demonstrate that snacking habits provide a unique contribution in explaining unhealthy snacking behaviour, stressing the importance of addressing habit strength in further research and interventions concerning unhealthy snacking behaviour. ©2012 The British Psychological Society.

  18. Data Acquistion Controllers and Computers that can Endure, Operate and Survive Cryogenic Temperatures, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Current and future NASA exploration flight missions require Avionics systems, Computers, Controllers and Data processing units that are capable of enduring extreme...

  19. Effects of Oral Sodium Supplementation on Indices of Thermoregulation in Trained, Endurance Athletes

    Directory of Open Access Journals (Sweden)

    Elizabeth L. Earhart, Edward P. Weiss, Rabia Rahman, Patrick V. Kelly

    2015-03-01

    Full Text Available Guidelines recommend the consumption of sodium during exercise to replace losses in sweat; however, the effects of sodium on thermoregulation are less clear. To determine the effects of high-dose sodium supplementation on indices of thermoregulation and related outcomes, 11 endurance athletes participated in a double-blind, randomized-sequence, crossover study in which they underwent 2-hrs of endurance exercise at 60% heart rate reserve with 1800 mg of sodium supplementation (SS during one trial and placebo (PL during the other trial. A progressive intensity time-to-exhaustion test was performed after the 2-hr steady state exercise as an assessment of exercise performance. Sweat rate was calculated from changes in body weight, accounting for fluid intake and urinary losses. Ratings of perceived exertion (RPE and heat stress were assessed using verbal numeric scales. Cardiovascular drift was determined from the rise in HR during the 2-hr steady state exercise test. Skin temperature was measured with an infrared thermometer. Dehydration occurred in both SS and PL trials, as evidenced by substantial weight loss (2.03 ± 0.43% and 2.27 ± 0.70%, respectively; p = 0.261 between trials. Sweat rate was 1015.53 ± 239.10 ml·hr-1 during the SS trial and 1053.60±278.24 ml/hr during the PL trial, with no difference between trials (p = 0.459. Heat stress ratings indicated moderate heat stress (“warm/hot” ratings but were not different between trials (p = 0.825. Time to exhaustion during the SS trial was 6.88 ± 3.88 minutes and during the PL trial averaged 6.96 ± 3.61 minutes, but did not differ between trials (p = 0.919. Cardiovascular drift, skin temperature, and RPE did not differ between trials (all p > 0.05. High-dose sodium supplementation does not appear to impact thermoregulation, cardiovascular drift, or physical performance in trained, endurance athletes. However, in light of the possibility that high sodium intakes might have other adverse

  20. Investigation of endurance limit- and low-cycle fatigue strength of St E 47 and STE 70 in the welded and unwelded state

    International Nuclear Information System (INIS)

    Jaenicke, B.; Helms, R.; Florian, W.; Lipp, H.J.; Seidl, W.; Kaiser, B.

    1979-01-01

    To clarify clear the effect of the welding conditions and the heat treatment, alternating load tests were carried out in the endurance limit- and low-cycle-fatigue strength range on specimens of St E 47 and St E 70. Grounded basic material flat specimens cleared from their rolling skins and welded flat specimens with a butt weld of special quality were used. The welds were produced by the metal arc manual welding method with bar electrodes (low heat introduction) and with the submerged-arc welding method (high heat introduction). Part of the specimens were tempered free from stress after welding. The tests were carried out force-controlled at tension-repeated loading (S=0) and strain controlled at tension-compression alternating loading (S approx. -1). In the range of N = 5 x 10 4 ...1,5 x 10 6 cycles a small effect of the welding (special quality) for St E 47 with subsequence tempering on the endurance limit was proofed, which in comparison with the unwelded basic material (grounded surface) was characterized by broad range at nearly the same endurance limit. For St E 70, a clear decrease of the endurance limit of welded, tempered specimens (special quality) was found as compared with the basic material (grounded surface). (orig./RW) 891 RW/orig.- 892 RKD [de

  1. EFFECTS OF HIGH INTENSITY TRAINING AND CONTINUOUS ENDURANCE TRAINING ON AEROBIC CAPACITY AND BODY COMPOSITION IN RECREATIONALLY ACTIVE RUNNERS

    Directory of Open Access Journals (Sweden)

    Kuno Hottenrott

    2012-09-01

    Full Text Available The aim of the study was to examine the effects of two different training programs (high-intensity-training vs. continuous endurance training on aerobic power and body composition in recreationally active men and women and to test whether or not participants were able to complete a half marathon after the intervention period. Thirty-four recreational endurance runners were randomly assigned either to a Weekend-Group (WE, n = 17 or an After-Work- Group (AW, n = 17 for a 12 week-intervention period. WE weekly completed 2 h 30 min of continuous endurance running composed of 2 sessions on the weekend. In contrast, AW performed 4 30 min sessions of high intensity training and an additional 30 min endurance run weekly, always after work. During an exhaustive treadmill test aerobic power was measured and heart rate was continuously recorded. Body composition was assessed using bio-impedance. Following the intervention period all subjects took part in a half-marathon. AW significantly improved peak oxygen uptake (VO2 peak from 36.8 ± 4.5 to 43.6 ± 6.5 [mL.min-1.kg-1], velocity at lactate threshold (VLT from 9.7 ± 2.2 to 11.7 ± 1.8 [km.h-1] and visceral fat from 5.6 ± 2.2 to 4.7 ± 1.9 In WE VO2 peak signifi-cantly increased from 38.8 ± 5.0 to 41.5 ± 6.0 [mL.min-1.kg-1], VLT from 9.9 ± 1.3 to 11.2 ± 1.7 [km.h-1] and visceral fat was reduced from 5.7 ± 2.1 to 5.4 ± 1.9 (p < 0.01. Only the improvements of VO2 peak were significantly greater in AW compared with WE (pre/post group interaction: F=15.4, p = 0.01, η2 = 0.36. Both groups completed a half marathon with no significant differences in performance (p = 0.63. Short, intensive endurance training sessions of about 30 min are effective in improving aerobic fitness in recreationally active runners

  2. Effects of solar radiation on endurance exercise capacity in a hot environment.

    Science.gov (United States)

    Otani, Hidenori; Kaya, Mitsuharu; Tamaki, Akira; Watson, Phillip; Maughan, Ronald J

    2016-04-01

    The present study investigated the effects of variations in solar radiation on endurance exercise capacity and thermoregulatory responses in a hot environment. Eight male volunteers performed four cycle exercise trials at 70 % maximum oxygen uptake until exhaustion in an environmental chamber maintained at 30 °C and 50 % relative humidity. Volunteers were tested under four solar radiation conditions: 800, 500, 250 and 0 W/m(2). Exercise time to exhaustion was less on the 800 W/m(2) trial (23 ± 4 min) than on all the other trials (500 W/m(2) 30 ± 7 min; P 0.05). Mean skin temperature was higher on the 800 W/m(2) trial than the 250 and 0 W/m(2) trials (P solar radiation increases.

  3. Effect of endurance versus resistance training on quadriceps muscle dysfunction in COPD

    DEFF Research Database (Denmark)

    Iepsen, Ulrik Winning; Munch, Gregers Druedal Wibe; Rugbjerg, Mette

    2016-01-01

    INTRODUCTION: Exercise is an important countermeasure to limb muscle dysfunction in COPD. The two major training modalities in COPD rehabilitation, endurance training (ET) and resistance training (RT), may both be efficient in improving muscle strength, exercise capacity, and health-related quality...... and after the training intervention to assess muscle morphology and metabolic and angiogenic factors. Symptom burden, exercise capacity (6-minute walking and cycle ergometer tests), and vascular function were also assessed. RESULTS: Both training modalities improved symptom burden and exercise capacity...... with no difference between the two groups. The mean (SD) proportion of glycolytic type IIa muscle fibers was reduced after ET (from 48% [SD 11] to 42% [SD 10], Ptraining modality on muscle...

  4. Somatic, Endurance Performance and Heart Rate Variability Profiles of Professional Soccer Players Grouped According to Age

    Directory of Open Access Journals (Sweden)

    Botek Michal

    2016-12-01

    Full Text Available This cross-sectional study compared somatic, endurance performance determinants and heart rate variability (HRV profiles of professional soccer players divided into different age groups: GI (17–19.9 years; n = 23, GII (20–24.9 years; n = 45, GIII (25–29.9 years; n = 30, and GIV (30–39 years; n = 26. Players underwent somatic and HRV assessment and maximal exercise testing. HRV was analyzed by spectral analysis of HRV, and high (HF and low (LF frequency power was transformed by a natural logarithm (Ln. Players in GIV (83 ± 7 kg were heavier (p 25 years showed negligible differences in Pmax unlike the age group differences demonstrated in VO2max. A shift towards relative sympathetic dominance, particularly due to reduced vagal activity, was apparent after approximately 8 years of competing at the professional level.

  5. Enduring somatic threat perceptions and post-traumatic stress disorder symptoms in survivors of cardiac events.

    Science.gov (United States)

    Meli, Laura; Alcántara, Carmela; Sumner, Jennifer A; Swan, Brendan; Chang, Bernard P; Edmondson, Donald

    2017-04-01

    Post-traumatic stress disorder due to acute cardiovascular events may be uniquely defined by enduring perceptions of somatic threat. We tested whether post-traumatic stress disorder at 1 month post-acute coronary syndrome indeed required both high peritraumatic threat during the acute coronary syndrome and ongoing cardiac threat perceptions. We assessed peritraumatic threat during emergency department enrollment of 284 patients with a provisional acute coronary syndrome diagnosis and cardiac threat perceptions and post-traumatic stress disorder symptoms 1 month post-discharge. In a multiple regression model with adjustment for important covariates, emergency department threat perceptions were associated with higher 1 month post-traumatic stress disorder symptoms only among those with high levels of ongoing cardiac threat.

  6. Prevalence of Stress Urinary Incontinence in Elite Female Endurance Athletes

    Directory of Open Access Journals (Sweden)

    Poświata Anna

    2014-12-01

    Full Text Available The goal of the study was to assess the prevalence of stress urinary incontinence in a group of elite female endurance athletes, as professional sport is one of the risk factors for stress urinary incontinence. SUI rates in the groups of female cross-country skiers and runners were compared to determine whether the training weather conditions like temperature and humidity influenced the prevalence of urinary incontinence. An anonymous questionnaire was distributed among 112 elite female athletes ie., 57 cross-country skiers and 55 runners. We used a short form of the Urogenital Distress Inventory (UDI-6 to assess the presence of SUI symptoms and the level of urogenital distress. Only women who had been practicing sport professionally for at least 3 years, on an international and national level, were included in the research. The study group consisted of 76% nulliparous and 24% parous women. 45.54% of all participants reported leakage of urine associated with sneezing or coughing which indicates stress urinary incontinence. 29.46% were not bothered by the urogenital distress symptoms. 42.86% of the participants were slightly bothered by the symptoms, 18.75% were moderately bothered, 8.04% were significantly bothered and 0.89% were heavily bothered. The absence of statistically significant differences between both groups seems to indicate that training weather conditions did not influence the prevalence of SUI in elite female endurance athletes.

  7. The influence of collective behaviour on pacing in endurance competitions

    Directory of Open Access Journals (Sweden)

    Andrew eRenfree

    2015-12-01

    Full Text Available A number of theoretical models have been proposed to explain pacing strategies in individual competitive endurance events. These have typically related to internal regulatory processes informing the making of decisions relating to muscular work rate. Despite a substantial body of research investigating the influence of collective group dynamics on individual behaviours in various animal species, this issue has not been comprehensively studied in individual athletic events. This is surprising given that athletes directly compete in close proximity to one another, and that collective behaviour has also been observed in other human environments. Whilst reasons for adopting collective behaviour are not fully understood, it is thought to result from individual agents following simple local rules resulting in seemingly complex large systems acting to confer some biological advantage to the collective as a whole. Although such collective behaviours may generally be beneficial, endurance events are complicated by the fact that increasing levels of physiological disruption as activity progresses may compromise the ability of individuals to continue to interact with other group members. This could result in early fatigue and relative underperformance due to suboptimal utilisation of physiological resources by some athletes. Alternatively, engagement with a collective behaviour may benefit all due to a reduction in the complexity of decisions to be made and a subsequent reduction in cognitive loading and mental fatigue. This paper seeks evidence for collective behaviour in previously published analyses of pacing behaviour and proposes mechanisms through which it could potentially be either beneficial, or detrimental to individual performance.

  8. Sensing Athletes: Sensory Dimensions of Recreational Endurance Sports

    Directory of Open Access Journals (Sweden)

    Stefan Groth

    2017-12-01

    Full Text Available Sport has become increasingly popular with recreational athletes over the last couple of decades. This has only gained minimal attention so far from scholars interested in the relations between recreational sports and everyday culture. With this paper, we seek to contribute to this field by scrutinising the sensory dimensions of recreational sport. Rather than probing into or highlighting isolated senses, we look at sensory dimensions understood as a combination of different, non-separable sensory experiences featured in recreational endurance sports. We are interested in how senses play a role for recreational endurance athletes in running, triathlon and cycling both in training and competition. We start by examining how cultural and social dimensions are inextricably linked to doing sports. Secondly, we show how different configurations of the senses and their communicative mediation are contingent on sport disciplines, specific settings, technology, development and change as sensory careers over time. Thirdly, we discuss the kinaesthetic dimensions of doing sports in relation to the senses and the role of atmospheres. We conclude by arguing that highlighting specific senses by athletes is a cultural practice that calls for a holistic analysis of senses in sport, and outline some methodological implications for research on the senses.

  9. An empirical study of race times in recreational endurance runners.

    Science.gov (United States)

    Vickers, Andrew J; Vertosick, Emily A

    2016-01-01

    Studies of endurance running have typically involved elite athletes, small sample sizes and measures that require special expertise or equipment. We examined factors associated with race performance and explored methods for race time prediction using information routinely available to a recreational runner. An Internet survey was used to collect data from recreational endurance runners (N = 2303). The cohort was split 2:1 into a training set and validation set to create models to predict race time. Sex, age, BMI and race training were associated with mean race velocity for all race distances. The difference in velocity between males and females decreased with increasing distance. Tempo runs were more strongly associated with velocity for shorter distances, while typical weekly training mileage and interval training had similar associations with velocity for all race distances. The commonly used Riegel formula for race time prediction was well-calibrated for races up to a half-marathon, but dramatically underestimated marathon time, giving times at least 10 min too fast for half of runners. We built two models to predict marathon time. The mean squared error for Riegel was 381 compared to 228 (model based on one prior race) and 208 (model based on two prior races). Our findings can be used to inform race training and to provide more accurate race time predictions for better pacing.

  10. Effects of hypoxia and hypercapnia on geniohyoid contractility and endurance.

    Science.gov (United States)

    Salmone, R J; Van Lunteren, E

    1991-08-01

    Sleep apnea and other respiratory diseases produce hypoxemia and hypercapnia, factors that adversely affect skeletal muscle performance. To examine the effects of these chemical alterations on force production by an upper airway dilator muscle, the contractile and endurance characteristics of the geniohyoid muscle were examined in situ during severe hypoxia (arterial PO2 less than 40 Torr), mild hypoxia (PO2 45-65 Torr), and hypercapnia (PCO2 55-80 Torr) and compared with hyperoxic-normocapnic conditions in anesthetized cats. Muscles were studied at optimal length, and contractile force was assessed in response to supramaximal electrical stimulation of the hypoglossal nerve (n = 7 cats) or geniohyoid muscle (n = 2 cats). There were no significant changes in the twitch kinetics or force-frequency curve of the geniohyoid muscle during hypoxia or hypercapnia. However, the endurance of the geniohyoid, as reflected in the fatigue index (ratio of force at 2 min to initial force in response to 40-Hz stimulation at a duty cycle 0.33), was significantly reduced by severe hypoxia but not by hypercapnia or mild hypoxia. In addition, the downward shift in the force-frequency curve after the repetitive stimulation protocol was greater during hypoxia than hyperoxia, especially at higher frequencies. In conclusion, the ability of the geniohyoid muscle to maintain force output during high levels of activation is adversely affected by severe hypoxia but not mild hypoxia or hypercapnia. However, none of these chemical perturbations affected muscle contractility acutely.

  11. Y-Chromosomal Diversity in Europe Is Clinal and Influenced Primarily by Geography, Rather than by Language

    Science.gov (United States)

    Rosser, Zoë H.; Zerjal, Tatiana; Hurles, Matthew E.; Adojaan, Maarja; Alavantic, Dragan; Amorim, António; Amos, William; Armenteros, Manuel; Arroyo, Eduardo; Barbujani, Guido; Beckman, Gunhild; Beckman, Lars; Bertranpetit, Jaume; Bosch, Elena; Bradley, Daniel G.; Brede, Gaute; Cooper, Gillian; Côrte-Real, Helena B. S. M.; de Knijff, Peter; Decorte, Ronny; Dubrova, Yuri E.; Evgrafov, Oleg; Gilissen, Anja; Glisic, Sanja; Gölge, Mukaddes; Hill, Emmeline W.; Jeziorowska, Anna; Kalaydjieva, Luba; Kayser, Manfred; Kivisild, Toomas; Kravchenko, Sergey A.; Krumina, Astrida; Kučinskas, Vaidutis; Lavinha, João; Livshits, Ludmila A.; Malaspina, Patrizia; Maria, Syrrou; McElreavey, Ken; Meitinger, Thomas A.; Mikelsaar, Aavo-Valdur; Mitchell, R. John; Nafa, Khedoudja; Nicholson, Jayne; Nørby, Søren; Pandya, Arpita; Parik, Jüri; Patsalis, Philippos C.; Pereira, Luísa; Peterlin, Borut; Pielberg, Gerli; Prata, Maria João; Previderé, Carlo; Roewer, Lutz; Rootsi, Siiri; Rubinsztein, D. C.; Saillard, Juliette; Santos, Fabrício R.; Stefanescu, Gheorghe; Sykes, Bryan C.; Tolun, Aslihan; Villems, Richard; Tyler-Smith, Chris; Jobling, Mark A.

    2000-01-01

    Clinal patterns of autosomal genetic diversity within Europe have been interpreted in previous studies in terms of a Neolithic demic diffusion model for the spread of agriculture; in contrast, studies using mtDNA have traced many founding lineages to the Paleolithic and have not shown strongly clinal variation. We have used 11 human Y-chromosomal biallelic polymorphisms, defining 10 haplogroups, to analyze a sample of 3,616 Y chromosomes belonging to 47 European and circum-European populations. Patterns of geographic differentiation are highly nonrandom, and, when they are assessed using spatial autocorrelation analysis, they show significant clines for five of six haplogroups analyzed. Clines for two haplogroups, representing 45% of the chromosomes, are continentwide and consistent with the demic diffusion hypothesis. Clines for three other haplogroups each have different foci and are more regionally restricted and are likely to reflect distinct population movements, including one from north of the Black Sea. Principal-components analysis suggests that populations are related primarily on the basis of geography, rather than on the basis of linguistic affinity. This is confirmed in Mantel tests, which show a strong and highly significant partial correlation between genetics and geography but a low, nonsignificant partial correlation between genetics and language. Genetic-barrier analysis also indicates the primacy of geography in the shaping of patterns of variation. These patterns retain a strong signal of expansion from the Near East but also suggest that the demographic history of Europe has been complex and influenced by other major population movements, as well as by linguistic and geographic heterogeneities and the effects of drift. PMID:11078479

  12. Suplementação de carboidrato não reverte o efeito deletério do exercício de endurance sobre o subseqüente desempenho de força Suministrar carbohidratos no revierte el efecto destructivo del ejercicio de endurance sobre el subsiguiente desempeño de fuerza Carbohydrate supplementation fails to revert the deleterious effects of endurance exercise upon subsequent strength performance

    Directory of Open Access Journals (Sweden)

    Marcelo Saldanha Aoki

    2003-10-01

    Full Text Available Estudos disponíveis na literatura demonstram que a realização prévia de um exercício de endurance afeta de modo adverso o desempenho no exercício de força subseqüente. Tal ocorrência pode estar relacionada a mudanças metabólicas induzidas pelo exercício de endurance. O objetivo deste trabalho foi verificar se a ingestão de carboidrato (CHO pode atenuar os efeitos de uma sessão aguda de exercício de endurance sobre o desempenho de força. A fim de testar essa hipótese, seis estudantes universitárias (164 ± 5,9cm; 64,9 ± 7,2kg, com experiência em treinamento de força, foram submetidas a um teste para a determinação do VO2pico (44 ± 4,3ml.min-1 e um teste de 1-RM para o leg press (186 ± 22,5kg seguido de um teste de repetições máximas (duas séries de leg press realizado a 70% de 1-RM até exaustão 1ª série 21 ± 2,6 e 2ª série 11 ± 1,9 repetições em dias diferentes. Seguindo um protocolo duplo-cego, os sujeitos foram submetidos a duas condições experimentais, recebendo uma bebida placebo (P ou outra contendo carboidrato (6% - maltodextrina, antes (500ml e durante (500ml a realização de uma sessão de exercício de endurance (corrida em esteira 70% do VO2pico por 45 minutos. Em seguida ao exercício de endurance, os indivíduos realizaram um teste de 1-RM seguido pelo teste de repetições máximas. Não foram observadas mudanças no teste de 1-RM e na concentração plasmática de glicose entre as condições experimentais (P x CHO. O número de repetições máximas a 70%-1RM apresentou decréscimo nas duas situações (P 1ª série 13 ± 2,9 repetições e 2ª série 6 ± 2,1 repetições; CHO 1ª série 15 ± 2,5 repetições e 2ª série 7 ± 1,7 repetições, p Los estudios disponibles en la literatura demuestran que la realización previa de un ejercicio de endurance afecta de modo adverso el desempeño en el ejercicio de fuerza subsiguiente. Tal ocurrencia puede estar relacionada a cambios metab

  13. Electroejaculation functions primarily by direct activation of pelvic musculature: Perspectives from a porcine model

    Directory of Open Access Journals (Sweden)

    Adam M.R. Groh

    2018-03-01

    Full Text Available Ejaculatory dysfunction is a significant cause of infertility in men that have incurred spinal cord injury or iatrogenic lesions to the sympathetic nerves in the retroperitoneum. For such patients, electroejaculation – whereby a voltage is applied transrectally under general anesthesia – is a highly-effective procedure to obtain ejaculate. At present, however, there remains uncertainty as to the physiological mechanism by which electroejaculation prompts seminal emission in males with neurogenic anejaculation. Thus, in the present study, we aimed to determine, for the first time, whether electroejaculation functions by mimicking a neurophysiological response, or by directly activating local pelvic musculature. Using electroejaculation in a novel porcine model, we monitored the strength of contraction of the internal urethral sphincter (a smooth muscle involved in ejaculation before and after lesioning its sympathetic innervation with a combination of progressively-worsening surgical and pharmacological insults in three anesthetized boars (46.1 ± 7.4 kg. Importantly, prior to this investigation, we confirmed the comparative structural anatomy of the porcine model to humans through gross dissection and histological analysis of the infrarenal retroperitoneal sympathetic nerves and ganglia in 18 unembalmed boars. Prior to sacrifice, three of these boars underwent functional testing to confirm control of the internal urethral sphincter by the hypogastric nerves. Our results demonstrate that electroejaculation-induced contraction of the internal urethral sphincter was preserved following each progressive neural insult compared to the control state (p > 0.05. In contrast, these same insults resulted in paralysis/paresis of the internal urethral sphincter when its sympathetic innervation was directly stimulated with bipolar electrodes (p < 0.05. Taken together, our results provide the first empirical evidence to suggest that

  14. Effects of umeclidinium/vilanterol on exercise endurance in COPD: a randomised study

    Directory of Open Access Journals (Sweden)

    John H. Riley

    2018-01-01

    Full Text Available This multicentre, randomised, double-blind, placebo-controlled, two-period crossover study assessed the effect of umeclidinium/vilanterol (UMEC/VI on exercise capacity in patients with chronic obstructive pulmonary disease (COPD using the endurance shuttle walk test (ESWT. Patients were randomised 1:1 to one of two treatment sequences: 1 UMEC/VI 62.5/25 µg followed by placebo or 2 placebo followed by UMEC/VI 62.5/25 µg. Each treatment was taken once daily for 12 weeks. The primary end-point was 3-h post-dose exercise endurance time (EET at week 12. Secondary end-points included trough forced expiratory volume in 1 s (FEV1 and 3-h post-dose functional residual capacity (FRC, both at week 12. COPD Assessment Test (CAT score at week 12 was also assessed. UMEC/VI treatment did not result in a statistically significant improvement in EET change from baseline at week 12 versus placebo (p=0.790. However, improvements were observed in trough FEV1 (206 mL, 95% CI 167–246, 3-h post-dose FRC (−346 mL, 95% CI −487 to −204 and CAT score (−1.07 units, 95% CI −2.09 to −0.05 versus placebo at week 12. UMEC/VI did not result in improvements in EET at week 12 versus placebo, despite improvements in measures of lung function, hyperinflation and health status.

  15. Effects of caffeine ingestion on endurance performance in mentally fatigued individuals.

    Science.gov (United States)

    Azevedo, Rafael; Silva-Cavalcante, Marcos David; Gualano, Bruno; Lima-Silva, Adriano E; Bertuzzi, Romulo

    2016-12-01

    To examine the effects of caffeine ingestion on physiological and perceptual responses in mentally fatigued individuals. Eight male physically active subjects completed four cycling constant-workload tests in four experimental conditions at 80 % of maximal power output: control (C), mental fatigue (MF), mental fatigue plus caffeine ingestion (5 mg/kg) (MF-CAF), and mental fatigue plus placebo (MF-PLA). The mental fatigue was induced by a continuous performance task A-X version (AX-CPT). Before and after the AX-CPT, the profile of mood state (POMS) and blood samples for lactate measurement were collected. Oxygen consumption ([Formula: see text]), rating of perceived exertion (RPE), and electromyography (EMG) activity were measured during the cycling test. The time to exhaustion in C, MF, MF-PLA, and MF-CAF were 251 ± 30, 222 ± 23, 248 ± 28, and 285 ± 42 s, respectively. Delta values (corrected by C condition) were higher in MF-CAF than MF (P = 0.031). MF-CAF reported higher Vigor scores when compared with C (P = 0.046) and MF (P = 0.020). RPE at the first minute was significantly higher in MF-PLA than in C (P = 0.050); at the second minute, RPE was higher in MF-PLA than in C (P = 0.049) and MF-CAF (P = 0.048). EMG activity was not different between the conditions. Caffeine ingestion increased approximately 14 % endurance performance after the induction of mental fatigue. This effect was accompanied by a tendency to improvement in mood state (i.e., vigor). Therefore, caffeine ingestion can promote a beneficial effect on endurance performance in mentally fatigued individuals.

  16. Test

    DEFF Research Database (Denmark)

    Bendixen, Carsten

    2014-01-01

    Bidrag med en kortfattet, introducerende, perspektiverende og begrebsafklarende fremstilling af begrebet test i det pædagogiske univers.......Bidrag med en kortfattet, introducerende, perspektiverende og begrebsafklarende fremstilling af begrebet test i det pædagogiske univers....

  17. Effect of Vertical, Horizontal, and Combined Plyometric Training on Explosive, Balance, and Endurance Performance of Young Soccer Players.

    Science.gov (United States)

    Ramírez-Campillo, Rodrigo; Gallardo, Francisco; Henriquez-Olguín, Carlos; Meylan, Cesar M P; Martínez, Cristian; Álvarez, Cristian; Caniuqueo, Alexis; Cadore, Eduardo L; Izquierdo, Mikel

    2015-07-01

    The aim of this study was to compare the effects of 6 weeks of vertical, horizontal, or combined vertical and horizontal plyometric training on muscle explosive, endurance, and balance performance. Forty young soccer players aged between 10 and 14 years were randomly divided into control (CG; n = 10), vertical plyometric group (VG; n = 10), horizontal plyometric group (HG; n = 10), and combined vertical and horizontal plyometric group (VHG; n = 10). Players performance in the vertical and horizontal countermovement jump with arms, 5 multiple bounds test (MB5), 20-cm drop jump reactive strength index (RSI20), maximal kicking velocity (MKV), sprint, change of direction speed (CODS), Yo-Yo intermittent recovery level 1 test (Yo-Yo IR1), and balance was measured. No significant or meaningful changes in the CG, apart from small change in the Yo-Yo IR1, were observed while all training programs resulted in meaningful changes in explosive, endurance, and balance performance. However, only VHG showed a statistically significant (p ≤ 0.05) increase in all performance test and most meaningful training effect difference with the CG across tests. Although no significant differences in performance changes were observed between experimental groups, the VHG program was more effective compared with VG (i.e., jumps, MKV, sprint, CODS, and balance performance) and HG (i.e., sprint, CODS, and balance performance) to small effect. The study demonstrated that vertical, horizontal, and combined vertical and horizontal jumps induced meaningful improvement in explosive actions, balance, and intermittent endurance capacity. However, combining vertical and horizontal drills seems more advantageous to induce greater performance improvements.

  18. Functional relationship between dominant and non-dominant hand in motor task - hand grip strength endurance

    Directory of Open Access Journals (Sweden)

    Kljajić Dragana

    2012-01-01

    Full Text Available The aim of this study was to determine the functional relationship between dominant and non-dominant hand in the strength endurance motor task - hand grip, in the referent population of healthy and young persons. For the purpose of the research we have implemented the method of isometric dynamometry and standardized hand grip test. The study included 48 participants, 23 of them being of female and 25 of male gender. The analysis of variance (ANOVA was used to determine the difference between the sets of variables in the function of gender and functional dimorphism, while the Bonferroni criterion was applied to determine the differences between pairs of individual variables. The difference between the maximum hand grip of dominant and non-dominant hand in female participants amounted to 9.28%, and in male ones 7.39% in favor of the dominant hand. There is no statistically significant difference between nondominant and dominant hand regarding the force endurance time aspect at 30%, 50% and 80% out of the maximum hand grip level, as well as at the absolute and relative force impulse indicators as an endurance measure. The value of gender dimorphism in relation to the absolute indicators of force momentum at 30%, 50% and 80% out of the maximum hand grip level in female participants is 0.9714, 0.9145, 0.9301, and in male participants 0.9515, 0.8264 and 0.8606. The force momentum indicators value at 30%, 50% and 80% out of the maximum hand grip level in female participants is ImpF30%=21167.58±6923.67 Ns, ImpF50%=10846.94±3800.56 Ns and ImpF80%=5438.46±1993.12 Ns, and in male participants ImpF30%=17734.03±6881.92 Ns, ImpF50%=13903.61±3437.76 Ns and ImpF80%=5117.53±1894.78 Ns. The obtained results can be used as the criteria for further research in special education and rehabilitation, medical and professional rehabilitation.

  19. Effects of Cycling vs. Running Training on Endurance Performance in Preparation for Inline Speed Skating.

    Science.gov (United States)

    Stangier, Carolin; Abel, Thomas; Hesse, Clemens; Claen, Stephanie; Mierau, Julia; Hollmann, Wildor; Strüder, Heiko K

    2016-06-01

    Winter weather conditions restrict regular sport-specific endurance training in inline speed skating. As a result, this study was designed to compare the effects of cycling and running training programs on inline speed skaters' endurance performance. Sixteen (8 men, 8 women) high-level athletes (mean ± SD 24 ± 8 years) were randomly assigned to 1 of 2 groups (running and cycling). Both groups trained twice a week for 8 weeks, one group on a treadmill and the other on a cycle ergometer. Training intensity and duration was individually calculated (maximal fat oxidation: ∼52% of V[Combining Dot Above]O2peak: 500 kcal per session). Before and after the training intervention, all athletes performed an incremental specific (inline speed skating) and 1 nonspecific (cycling or running) step test according to the group affiliation. In addition to blood lactate concentration, oxygen uptake (V[Combining Dot Above]O2), ventilatory equivalent (VE/V[Combining Dot Above]O2), respiratory exchange ratio (RER), and heart rate were measured. The specific posttest revealed significantly increased absolute V[Combining Dot Above]O2peak values (2.9 ± 0.4, 3.4 ± 0.7, p = 0.01) and submaximal V[Combining Dot Above]O2 values (p ≤ 0.01). VE/V[Combining Dot Above]O2 and RER significantly decreased at maximal (46.6 ± 6.6, 38.5 ± 3.4, p = 0.005; 1.1 ± 0.03, 1.0 ± 0.04, p = 0.001) and submaximal intensities (p ≤ 0.04). None of the analysis revealed a significant group effect (p ≥ 0.15). The results indicate that both cycling vs. running exercise at ∼52% of V[Combining Dot Above]O2peak had a positive effect on the athletes' endurance performance. The increased submaximal V[Combining Dot Above]O2 values indicate a reduction in athletes' inline speed skating technique. Therefore, athletes would benefit from a focus on technique training in the subsequent period.

  20. Metabolic clues regarding the enhanced performance of elite endurance athletes from orchiectomy-induced hormonal changes.

    Science.gov (United States)

    Atwood, Craig S; Bowen, Richard L

    2007-01-01

    This article examines the metabolic performance of an elite cyclist, Lance Armstrong, before and after his diagnosis with testicular cancer. Although a champion cyclist in 1-day events prior to his diagnosis of testicular cancer at age 25, he was not a contender in multi-day endurance cycle races such as the 3-week Tour de France. His genetic makeup and physiology (high VO2max, long femur, strong heavy build) coupled with his ambition and motivation enabled him at an early age to become one of the best 1-day cyclists in the world. Following his cancer diagnosis, he underwent a unilateral orchiectomy, brain surgery and four cycles of chemotherapy. After recovering, he returned to cycling and surprisingly excelled in the Tour de France, winning this hardest of endurance events 7 years running. This dramatic transformation from a 1-day to a 3-week endurance champion has led many to query how this is possible, and under the current climate, has led to suggestions of doping as to the answer to this metamorphosis. Physiological tests following his recovery indicated that physiological parameters such as VO2max were not affected by the unilateral orchiectomy and chemotherapy. We propose that his dramatic improvement in recovery between stages, the most important factor in winning multi-day stage races, is due to his unilateral orchiectomy, a procedure that results in permanent changes in serum hormones. These hormonal changes, specifically an increase in gonadotropins (and prolactin) required to maintain serum testosterone levels, alter fuel metabolism; increasing hormone sensitive lipase expression and activity, promoting increased free fatty acid (FFA) mobilization to, and utilization by, muscles, thereby decreasing the requirement to expend limiting glycogen stores before, during and after exercise. Such hormonal changes also have been associated with ketone body production, improvements in muscle repair and haematocrit levels and may facilitate the loss of body weight

  1. Effects of Combined Training with Breathing Resistance and Sustained Physical Exertion to Improve Endurance Capacity and Respiratory Muscle Function in Healthy Young Adults

    OpenAIRE

    Kido, Satoshi; Nakajima, Yasuhiro; Miyasaka, Tomoya; Maeda, Yusuke; Tanaka, Toshiaki; Yu, Wenwei; Maruoka, Hiroshi; Takayanagi, Kiyomi

    2013-01-01

    [Purpose] In this study, combined training with breathing resistance and sustained physical exertion was carried out to evaluate its physiological effects and its effect on improve endurance capacity. [Subjects and Methods] The subjects were nine healthy adults (mean age 20.4, SD ? 1.7?years). The combined training group (n = 5) carried out 6 weeks of combined training using a cycle ergometer, with exercise load tests and respiratory function tests performed before and after the training. The...

  2. Vitamins and endurance training. Food for running or faddish claims?

    Science.gov (United States)

    van der Beek, E J

    1985-01-01

    The inter-relationship of food and physical performance, food is considered as a conglomerate of nutrients and man is depicted as a kind of organic pudding. This 'machine' concept of human performance in combination with the mysticism surrounding vitamins, has led to the faddish belief that additional vitamins are necessary to improve physical performance by means of supercharging the metabolic processes in the body. Various vitamins and their dietary recommendations as well as the indicators for vitamin status are discussed. It is concluded that a marginal or subclinical deficiency state can be defined as an intermediate between optimal vitamin status and frank clinical deficiency. Marginal deficiency is characterised by biochemical values deviating from statistically derived reference limits as well as the absence of clinical signs and symptoms of vitamin deficiency. Besides the static, mostly biochemical, indicators of vitamin status, more functional indicators are considered, among them work capacity. An extensive historical review on depletion studies, epidemiological surveys and supplementation studies is presented. It is concluded that a restricted intake of some B-complex vitamins-individually and in combination-of approximately less than 35 to 45% of the recommended dietary allowance may lead to decreased endurance capacity within a few weeks. Studies on ascorbic acid (vitamin C) depletion and fat-soluble vitamin A deficiency have noted no decrease of endurance capacity. However, in a few recent epidemiological surveys, biochemical vitamin C deficiency was actually shown to decrease aerobic power. Although the general conclusion is that a reduced water-soluble vitamin intake decreases endurance capacity, it is believed that further controlled experimentation is needed with B-complex vitamins and vitamin C individually. Furthermore, usually employed reference limits for vitamins need reappraisal translating them into impairment limits. With respect to the

  3. Testes de força e resistência muscular: confiabilidade e predição de uma repetição máxima - Revisão e novas evidências Tests de fuerza y resistencia muscular: confiabilidad de la prediccion de una repeticion máxima - Revision y nuevas evidencias Muscular strength and endurance tests: reliability and prediction of one repetition maximum - Review and new evidences

    Directory of Open Access Journals (Sweden)

    Marta Inez Rodrigues Pereira

    2003-10-01

    Full Text Available A confiabilidade intra-avaliadores é fundamental na determinação da qualidade dos dados coletados em uma pesquisa. Poucos estudos controlados têm reportado valores de confiabilidade de testes de força e, apesar de esta ser considerada boa na maioria dos estudos publicados (0,79 a 0,99, as diferenças entre teste e reteste têm sido observadas como estatisticamente significativas. Dessa forma, sugere-se a utilização dos valores de um segundo teste, pelo menos, em estudos de pesquisa, de modo que eventuais modificações nos valores de força possam ser atribuídas ao efeito dos tratamentos realizados e não à simples adaptação ao protocolo de teste. As relações entre testes de força máxima e testes submáximos ou variáveis antropométricas têm sido investigadas com o intuito de predizer a força máxima sem que o indivíduo tenha que ser submetido a um teste de carga máxima, evitando possíveis riscos de lesão. Valores de carga máxima, ou percentuais desta, são comumente utilizados para melhor prescrever o treinamento. A predição de uma repetição máxima (1RM através de testes submáximos parece boa (em geral, correlações > 0,90; entretanto, na maioria dos estudos revisados, as equações preditivas desenvolvidas quase sempre não são aprovadas no escrutínio de uma validação cruzada. Assim sendo, especial atenção deve ser dispensada à especificidade da população, do exercício e da técnica de execução, quando do desenvolvimento e aplicação dessas equações. Variáveis antropométricas não foram confirmadas como boas preditoras de 1RM. O número de repetições para dado % de 1RM é diferente para diferentes exercícios, como também o é a carga para determinado número de repetições máximas (nRM, quando executadas em diferentes velocidades. A prescrição do exercício baseada, indiferentemente, em número de repetições ou % de 1RM deve ser considerada com cautela.La confiabilidad entre los

  4. The Yo-Yo IE2 test

    DEFF Research Database (Denmark)

    Krustrup, Peter; Bradley, Paul S; Christensen, Jesper F

    2015-01-01

    To examine the physical capacity and physiological response to the Yo-Yo Intermittent Endurance level 2 test (IE2) for untrained individuals and trained male soccer players, and to investigate the determinants of intense intermittent exercise performance.......To examine the physical capacity and physiological response to the Yo-Yo Intermittent Endurance level 2 test (IE2) for untrained individuals and trained male soccer players, and to investigate the determinants of intense intermittent exercise performance....

  5. Effects of Three Commercially Available Sports Drinks on Substrate Metabolism and Subsequent Endurance Performance in a Postprandial State

    Directory of Open Access Journals (Sweden)

    Lu Qin

    2017-04-01

    Full Text Available Purpose: To examine the effects of commercially available sports beverages with various components on substrate metabolism and subsequent performance. Methods: Two studies were conducted in a double-blinded, counterbalanced manner. Study I was designed to determine the glycemic index, while study II determined the utilization of substrates and subsequent exercise performance. Ten healthy male participants (age 21.70 ± 2.41 years, height 176.60 ± 5.23 cm, weight 66.58 ± 5.38 kg, V̇O2max 48.1 ± 8.4 mL/kg/min participated in both study I and study II. Three types of commercially available sports beverage powders were used. The powders consisted primarily of oligosaccharides (low molecular weight carbohydrates, L-CHO, hydrolyzed starch (high molecular weight CHO, H-CHO, and whey protein powder with carbohydrate (CHO-PRO. They were dissolved in purified water with identical CHO concentration of 8% (w/v. In study I, each participant underwent two oral glucose tolerance tests (OGTT and one glycemic response test for each sports drink. In study II, participants cycled for 60 min at 70% V̇O2max, one hour after consuming a standardized breakfast. One of four prescribed beverages (L-CHO, H-CHO, CHO-PRO, and Placebo control, PLA was served at 0, 15, 30, 45 min during the exercise. Six hours after the first exercise session, participants came back for a “time to exhaustion test” (TTE. Blood samples were drawn at 0, 30, and 60 min in the first exercise session, while arterial blood gas analysis was conducted at 0, 30, and 60 min in both sessions. Subjective feelings (rating of perceived exertion and abdominal discomfort were also evaluated every 30 min during exercise. Results: Compared to the reference standardized glucose solution, the glycemic index of the L-CHO beverage was 117.70 ± 14.25, while H-CHO was 105.50 ± 12.82, and CHO-PRO was 67.23 ± 5.88. During the exercise test, the insulin level at 30 and 60 min was significantly lower than

  6. Defense Forensics: Additional Planning and Oversight Needed to Establish an Enduring Expeditionary Forensic Capability

    Science.gov (United States)

    2013-06-01

    forensic pathology, forensic anthropology, and forensic toxicology . 13DOD’s forensic directive defines DOD components as the Office of the...DEFENSE FORENSICS Additional Planning and Oversight Needed to Establish an Enduring Expeditionary Forensic ...COVERED 00-00-2013 to 00-00-2013 4. TITLE AND SUBTITLE Defense Forensics : Additional Planning and Oversight Needed to Establish an Enduring

  7. Masked hypertension and cardiac remodeling in middle-aged endurance athletes

    OpenAIRE

    Trachsel, Lukas; Carlen, Frederic; Brugger, Nicolas Jacques; Seiler, Christian; Wilhelm, Matthias

    2015-01-01

    OBJECTIVES: Extensive endurance training and arterial hypertension are established risk factors for atrial fibrillation. We aimed to assess the proportion of masked hypertension in endurance athletes and the impact on cardiac remodeling, mechanics, and supraventricular tachycardias (SVT). METHODS: Male participants of a 10-mile race were recruited and included if office blood pressure was normal (

  8. Development of the interval endurance capacity in elite and sub-elite youth field hockey players

    NARCIS (Netherlands)

    Elferink-Gemser, MT; Visscher, C; van Duijn, MAJ; Lemmink, KAPM

    Objectives: To gain more insight into the mechanisms that underlie the development of interval endurance capacity in talented youth field hockey players in the 12-19 age band. Methods: A total of 377 measurements were taken over three years. A longitudinal model for interval endurance capacity was

  9. Menstrual Cycle Effects on Anaerobic Power, Muscular Strength, and Muscular Endurance in Trained and Untrained Females.

    Science.gov (United States)

    Rosenburg, Beth S.; And Others

    A study determined if anaerobic power, isometric strength, and isometric endurance are affected by the menstrual cycle and if endurance trained females and untrained females are affected in the same manner on these performance parameters. Subjects were healthy, normally menstruating females, ages 18-34 years who were classified as either trained…

  10. Muscle Glycogen Content Modifies SR Ca2 + Release Rate in Elite Endurance Athletes

    DEFF Research Database (Denmark)

    Gejl, Kasper Degn; Hvid, Lars G; Frandsen, Ulrik

    2014-01-01

    The aim of the present study was to investigate the influence of muscle glycogen content on sarcoplasmic reticulum (SR) function and peak power output (Wpeak) in elite endurance athletes.......The aim of the present study was to investigate the influence of muscle glycogen content on sarcoplasmic reticulum (SR) function and peak power output (Wpeak) in elite endurance athletes....

  11. Combined speed endurance and endurance exercise amplify the exercise-induced PGC-1α and PDK4 mRNA response in trained human muscle

    DEFF Research Database (Denmark)

    Skovgaard, Casper; Brandt, Nina; Pilegaard, Henriette

    2016-01-01

    The aim of this study was to investigate the mRNA response related to mitochondrial biogenesis, metabolism, angiogenesis, and myogenesis in trained human skeletal muscle to speed endurance exercise (S), endurance exercise (E), and speed endurance followed by endurance exercise (S + E). Seventeen...... trained male subjects (maximum oxygen uptake (VO2-max): 57.2 ± 3.7 (mean ± SD) mL·min(-1)·kg(-1)) performed S (6 × 30 sec all-out), E (60 min ~60% VO2-max), and S + E on a cycle ergometer on separate occasions. Muscle biopsies were obtained at rest and 1, 2, and 3 h after the speed endurance exercise (S...... and S + E) and at rest, 0, 1, and 2 h after exercise in E In S and S + E, muscle peroxisome proliferator-activated receptor-γ coactivator-1 (PGC-1α) and pyruvate dehydrogenase kinase-4 (PDK4) mRNA were higher (P endurance exercise than at rest. Muscle PGC-1α and PDK4 m...

  12. Effects of an intervention based on the Transtheoretical Model on back muscle endurance, physical function and pain in rice farmers with chronic low back pain.

    Science.gov (United States)

    Thanawat, Thanakorn; Nualnetr, Nomjit

    2017-01-01

    Chronic low back pain (LBP) can be managed by exercises which should be tailored to an individual's readiness to behavioral change. To evaluate the effects of an intervention program based on the Transtheoretical Model of behavioral change (TTM) on back muscle endurance, physical function and pain in rice farmers with chronic LBP. In a 32-week study, 126 rice farmers were allocated to the TTM (n= 62) and non-TTM (n= 64) groups. Modified Biering-Sorensen test, Oswestry Disability Questionnaire and visual analogue scale were used for evaluating back muscle endurance, physical function and severity of pain, respectively. The evaluations were performed at baseline and at weeks 8, 20 and 32 of the study. Data were analyzed using repeated measure ANOVA. The back muscle endurance was significantly greater in the TTM group than in the non-TTM group at week 32 (p= 0.025). Physical function and severity of pain were significantly improved in the TTM group when compared with the non-TTM group at weeks 20 and 32 (pback muscle endurance and physical function, and reduce the pain in rice farmers with LBP. Further studies should be considered to explore the long-term effects of this intervention.

  13. Significant Effect of a Pre-Exercise High-Fat Meal after a 3-Day High-Carbohydrate Diet on Endurance Performance

    Directory of Open Access Journals (Sweden)

    Ikuma Murakami

    2012-06-01

    Full Text Available We investigated the effect of macronutrient composition of pre-exercise meals on endurance performance. Subjects consumed a high-carbohydrate diet at each meal for 3 days, followed by a high-fat meal (HFM; 1007 ± 21 kcal, 30% CHO, 55% F and 15% P or high-carbohydrate meal (HCM; 1007 ± 21 kcal, 71% CHO, 20% F and 9% P 4 h before exercise. Furthermore, just prior to the test, subjects in the HFM group ingested either maltodextrin jelly (M or a placebo jelly (P, while subjects in the HCM ingested a placebo jelly. Endurance performance was measured as running time until exhaustion at a speed between lactate threshold and the onset of blood lactate accumulation. All subjects participated in each trial, randomly assigned at weekly intervals. We observed that the time until exhaustion was significantly longer in the HFM + M (p < 0.05 than in HFM + P and HCM + P conditions. Furthermore, the total amount of fat oxidation during exercise was significantly higher in HFM + M and HFM + P than in HCM + P (p < 0.05. These results suggest that ingestion of a HFM prior to exercise is more favorable for endurance performance than HCM. In addition, HFM and maltodextrin ingestion following 3 days of carbohydrate loading enhances endurance running performance.

  14. Test Ship

    Data.gov (United States)

    Federal Laboratory Consortium — The U. S. Navy dedicated the decommissioned Spruance Class destroyer ex-PAUL F. FOSTER (EDD 964), Test Ship, primarily for at sea demonstration of short range weapon...

  15. Comprehensive study of endurance for IAR-99 Hawk

    Directory of Open Access Journals (Sweden)

    Dorin LOZICI-BRINZEI

    2014-03-01

    Full Text Available The paper presents some methods of on-ground and in-flight calibration for strain gauges, intended to the development of complex programs which analyze the endurance phenomena for aerospace structures, with direct application to the IAR-99 Hawk. The strain gauges have the advantage of being sensitive to load and therefore to aerodynamic phenomena, thereby providing indications of the loads supported by the structure. The effects size of loads type phenomena caused by wind gusts or buffet can be measured only by strain gauges or accelerometres70 and they cannot be recorded by flight or fatigue parameters counters. The installation of a strain gauge is made using a pattern (its position and orientation are crucial and the strain gauge selected for installation should not be fragile or unstable. Routines should be established for periodic inspection of strain gauges and those which are defective should be replaced immediately.

  16. Subclinical Theileria Equi Infection and Rhabdomyolysis in Three Endurance Horses

    Directory of Open Access Journals (Sweden)

    A. Muñoz1,2*, R. G. M. Rodríguez2, C. Riber1,2, P. Trigo2, M. Gómez-Díez2 and F. Castejon2

    2013-04-01

    Full Text Available Three well-trained endurance horses, competing over different distances, developed sudden and unexpected rhabdomyolysis at the onset of exercise. They were treated and afterwards they did not have any other bout of muscle damage. All of them were positive to Theileria equi (polymerase reaction chain. The possible reasons of the rhabdomyolysis could have been the direct effect of the parasite on the muscle and/or the result of the anemia and a limited oxygen supply to the exercising muscles. It is suggested that the horses were carriers of Theileria and they developed clinical signs because of the immune-suppression caused by prolonged submaximal exercise and/or transportation.

  17. Structural, Synaptic, and Epigenetic Dynamics of Enduring Memories

    Directory of Open Access Journals (Sweden)

    Ossama Khalaf

    2016-01-01

    Full Text Available Our memories are the records of the experiences we gain in our everyday life. Over time, they slowly transform from an initially unstable state into a long-lasting form. Many studies have been investigating from different aspects how a memory could persist for sometimes up to decades. In this review, we highlight three of the greatly addressed mechanisms that play a central role for a given memory to endure: the allocation of the memory to a given neuronal population and what brain areas are recruited for its storage; the structural changes that underlie memory persistence; and finally the epigenetic control of gene expression that might regulate and support memory perseverance. Examining such key properties of a memory is essential towards a finer understanding of its capacity to last.

  18. Structural, Synaptic, and Epigenetic Dynamics of Enduring Memories

    Science.gov (United States)

    Khalaf, Ossama; Gräff, Johannes

    2016-01-01

    Our memories are the records of the experiences we gain in our everyday life. Over time, they slowly transform from an initially unstable state into a long-lasting form. Many studies have been investigating from different aspects how a memory could persist for sometimes up to decades. In this review, we highlight three of the greatly addressed mechanisms that play a central role for a given memory to endure: the allocation of the memory to a given neuronal population and what brain areas are recruited for its storage; the structural changes that underlie memory persistence; and finally the epigenetic control of gene expression that might regulate and support memory perseverance. Examining such key properties of a memory is essential towards a finer understanding of its capacity to last. PMID:26933513

  19. Left Ventricular Function After Prolonged Exercise in Equine Endurance Athletes

    DEFF Research Database (Denmark)

    Flethøj, M.; Schwarzwald, C. C.; Haugaard, M. M.

    2016-01-01

    Doppler imaging, and two-dimensional speckle tracking. Correlation between echocardiographic variables and cardiac troponin I was evaluated. Results: Early diastolic myocardial velocities decreased significantly in longitudinal (baseline: −17.4 ± 2.4cm/s; end of ride: −15.8 ± 3.2cm/s (P = .013); morning......Background: Prolonged exercise in human athletes is associated with transient impairment of left ventricular (LV) function, known as cardiac fatigue. Cardiac effects of prolonged exercise in horses remain unknown. Objectives :To investigate the effects of prolonged exercise on LV systolic...... and diastolic function in horses. Animals: Twenty-six horses competing in 120–160 km endurance rides. Methods: Cross-sectional field study. Echocardiography was performed before and after rides, and the following morning, and included two-dimensional echocardiography, anatomical M-mode, pulsed-wave tissue...

  20. Can endurance exercise preconditioning prevention disuse muscle atrophy?

    Directory of Open Access Journals (Sweden)

    Michael P Wiggs

    2015-03-01

    Full Text Available Emerging evidence suggests that exercise training can provide a level of protection against disuse muscle atrophy. Endurance exercise training imposes oxidative, metabolic, and heat stress on skeletal muscle which activates a variety of cellular signaling pathways that ultimately leads to the increased expression of proteins that have been demonstrated to protect muscle from inactivity –induced atrophy. This review will highlight the effect of exercise-induced oxidative stress on endogenous enzymatic antioxidant capacity (i.e., superoxide dismutase, glutathione peroxidase, and catalase, the role of oxidative and metabolic stress on PGC1-α, and finally highlight the effect heat stress and HSP70 induction. Finally, this review will discuss the supporting scientific evidence that these proteins can attenuate muscle atrophy through exercise preconditioning.

  1. Reference Values for Inspiratory Muscle Endurance in Healthy Children and Adolescents.

    Directory of Open Access Journals (Sweden)

    Cristhiele Taís Woszezenki

    Full Text Available To generate reference values for two inspiratory muscle endurance (IME protocols in healthy children and adolescents.This is an observational, cross-sectional study, in healthy children and adolescents from 4 to 18 years of age. Weight, height, maximal inspiratory pressure (MIP and IME were measured using two protocols. A fixed load of 30% of MIP with a 10% increment every 2 minutes was used in the incremental threshold loading protocol. As for the maximal loading protocol, a fixed load of 70% of MIP was used and the time limit (Tlim achieved until fatigue was measured.A total of 462 participants were included, 281 corresponding to the incremental loading protocol and 181 to maximal loading. There were moderate and positive correlations between IME and age, MIP, weight and height in the incremental threshold loading. However, the regression model demonstrated that MIP and age were the best variables to predict the IME. Otherwise, weak and positive correlations with age, weight and height were found in the maximal loading. Only age and height influenced endurance in the regression model. The predictive power (r2 of the incremental threshold loading protocol was 0.65, while the maximal loading was 0.15. The reproducibility measured by the intraclass correlation coefficient (ICC was higher in the incremental loading (0.96 compared to the maximal loading test (0.69.IME in healthy children and adolescents can be explained by age, height and MIP. The incremental threshold loading protocol showed more reliable results and should be the model of choice to evaluate IME in the pediatric age group.

  2. Energetics of endurance exercise in young horses determined by nuclear magnetic resonance metabolomics

    Directory of Open Access Journals (Sweden)

    Margaux Marie-Hélène, Olivia Luck

    2015-07-01

    Full Text Available Long-term endurance exercise severely affects metabolism in both human and animal athletes resulting in serious risk of metabolic disorders during or after competition. Young horses (up to 6 years old can compete in races up to 90 km despite limited scientific knowledge of energetic metabolism responses to long distance exercise in these animals. The hypothesis of this study was that there would be a strong effect of endurance exercise on the metabolomic profiles of young horses and that the energetic metabolism response in young horses would be different from that of more experienced horses. Metabolomic profiling is a powerful method that combines Nuclear magnetic resonance (NMR spectrometry with supervised orthogonal projection on latent structure (OPLS statistical analysis. 1H-NMR spectra were obtained from plasma samples drawn from young horses (before and after competition. The spectra obtained before and after the race from the same horse (92 samples were compared using OPLS. The statistical parameters showed the robustness of the model (R2Y=0.947, Q2Y=0.856 and CV-ANOVA p-value < 0.001. For confirmation of the predictive value of the model, a test set of 104 sample spectra were projected by the model, which provided perfect predictions as the area under the receiving-operator curve was 1. The metabolomic profile determined with the OPLS model showed that glycemia after the race was lower than glycemia before the race, despite the involvement of lipid and protein catabolism. An OPLS model was calculated to compare spectra obtained on plasma taken after the race from 6-year-old horses and from experienced horses (cross-validated ANOVA p-value < 0.001. The comparison of metabolomic profiles in young horses to those from experienced horses showed that experienced horses maintained their glycemia with higher levels of lactate and a decrease of plasma lipids after the race.

  3. The metabolic and performance effects of caffeine compared to coffee during endurance exercise.

    Science.gov (United States)

    Hodgson, Adrian B; Randell, Rebecca K; Jeukendrup, Asker E

    2013-01-01

    There is consistent evidence supporting the ergogenic effects of caffeine for endurance based exercise. However, whether caffeine ingested through coffee has the same effects is still subject to debate. The primary aim of the study was to investigate the performance enhancing effects of caffeine and coffee using a time trial performance test, while also investigating the metabolic effects of caffeine and coffee. In a single-blind, crossover, randomised counter-balanced study design, eight trained male cyclists/triathletes (Mean ± SD: Age 41 ± 7 y, Height 1.80 ± 0.04 m, Weight 78.9 ± 4.1 kg, VO2 max 58 ± 3 ml • kg(-1) • min(-1)) completed 30 min of steady-state (SS) cycling at approximately 55% VO2max followed by a 45 min energy based target time trial (TT). One hour prior to exercise each athlete consumed drinks consisting of caffeine (5 mg CAF/kg BW), instant coffee (5 mg CAF/kg BW), instant decaffeinated coffee or placebo. The set workloads produced similar relative exercise intensities during the SS for all drinks, with no observed difference in carbohydrate or fat oxidation. Performance times during the TT were significantly faster (~5.0%) for both caffeine and coffee when compared to placebo and decaf (38.35 ± 1.53, 38.27 ± 1.80, 40.23 ± 1.98, 40.31 ± 1.22 min respectively, pperformance times were similar for both caffeine and coffee. Average power for caffeine and coffee during the TT was significantly greater when compared to placebo and decaf (294 ± 21 W, 291 ± 22 W, 277 ± 14 W, 276 ± 23 W respectively, pcaffeine (5 mg/kg/BW) and coffee (5 mg/kg/BW) consumed 1 h prior to exercise can improve endurance exercise performance.

  4. The association of trunk muscle cross-sectional area and magnetic resonance image parameters with isokinetic and psychophysical lifting strength and static back muscle endurance in men.

    Science.gov (United States)

    Gibbons, L E; Latikka, P; Videman, T; Manninen, H; Battié, M C

    1997-10-01

    The relationship between trunk muscle morphology as measured on transverse magnetic resonance images and isokinetic lifting, psychophysical lifting, and static back muscle endurance testing was examined in 110 men, ages 35-67 years (mean, 48 years), who had been chosen based on their exposure to a wide variety of occupational and leisure-time physical activities. The computed T2-relaxation times and the T2-weighted and proton density-weighted signal intensities of the erector spinae, quadratus lumborum, and psoas major muscles had almost no association with any of the strength tests. The cross-sectional areas of the muscles had good correlations with isokinetic lifting strength (r = 0.46-0.53). They did not correlate well with psychophysical lifting and static back muscle endurance. Other characteristics or neurological or psychological factors may have more influence on those tests.

  5. Altitude Training and its Influence on Physical Endurance in Swimmers

    Science.gov (United States)

    Strzała, Marek; Ostrowski, Andrzej; Szyguła, Zbigniew

    2011-01-01

    It is possible to plan an altitude training (AT) period in such a way that the enhanced physical endurance obtained as a result of adaptation to hypoxia will appear and can be used to improve performance in competition. Yet finding rationales for usage of AT in highly trained swimmers is problematic. In practice AT, in its various forms, is still controversial, and an objective review of research concentrating on the advantages and disadvantages of AT has been presented in several scientific publications, including in no small part the observations of swimmers. The aim of this article is to review the various methods and present both the advantageous and unfavourable physiological changes that occur in athletes as a result of AT. Moreover, AT results in the sport of swimming have been collected. They include an approach towards primary models of altitude/hypoxic training: live high + train high, live high + train low, live low + train high, as well as subsequent methods: Intermittent Hypoxic Exposure (IHE) and Intermittent Hypoxic Training (IHT). Apnoea training, which is descended from freediving, is also mentioned, and which can be used with, or as a substitute for, the well-known IHE or IHT methods. In conclusion, swimmers who train using hypoxia may be among the best-trained athletes, and that even a slight improvement in physical endurance might result in the shortening of a swimming time in a given competition, and the achievement of a personal best, which is hard to obtain by normal training methods, when the personal results of the swimmer have reached a plateau. PMID:23486564

  6. Skeletal Muscle Response to Endurance Training in IL-6-/- Mice.

    Science.gov (United States)

    Wojewoda, M; Kmiecik, K; Majerczak, J; Ventura-Clapier, R; Fortin, D; Onopiuk, M; Rog, J; Kaminski, K; Chlopicki, S; Zoladz, J A

    2015-12-01

    We examined effects of moderate-intensity endurance training on muscle COX/CS activities and V'O2max in control WT and IL-6(-/-) mice. Animals were exercised for 10 weeks on treadmill for 1 h, 5 days a week at velocity of 6 m·min(-1) which was increased by 0.5 m·min(-1) every 2 weeks up to 8 m·min(-1) . Training triggered an increase of enzyme activities in soleus muscle of WT mice (COX: 480.3±8.9 U·g(-1) in sedentary group vs. 773.3±62.6 U·g(-1) in trained group, P<0.05 and CS: 374.0±6.0 U·g(-1) in sedentary group vs. 534.2±20.5 U·g(-1) in trained group, P<0.01, respectively) whereas no changes were observed in soleus of IL6(-/-) mice. Moreover, in mixed gastrocnemius muscle of trained IL-6(-/-) mice enzyme activities tended to be lower (COX: 410.7±48.4 U·g(-1) for sedentary vs. 277.0±36.5 U·g(-1) for trained group and CS: 343.8±24.6 U·g(-1) for sedentary vs. 251.7±27.1 U·g(-1) for trained group). No changes in V'O2max were observed in WT and IL-6(-/-) mice after training. Concluding, moderate-velocity endurance training-induced increase in COX and CS activities in muscles of WT mice only which suggests that IL-6 regulates training-induced skeletal muscle responses to exercise. © Georg Thieme Verlag KG Stuttgart · New York.

  7. Examining Change in K-3 Teachers' Mathematical Knowledge, Attitudes, and Beliefs: The Case of Primarily Math

    Science.gov (United States)

    Kutaka, T. S.; Ren, L.; Smith, W. M.; Beattie, H. L.; Edwards, C. P.; Green, J. L.; Chernyavskiy, P.; Stroup, W.; Heaton, R. M.; Lewis, W. J.

    2018-01-01

    This study examines the impact of the Primarily Math Elementary Mathematics Specialist program on K-3 teachers' mathematical content knowledge for teaching, attitudes toward learning mathematics, and beliefs about mathematics teaching and learning. Three cohorts of teachers participating in the program were compared to a similar group of…

  8. Endurance training in mild hypertension - effects on ambulatory blood pressure and neural circulatory control.

    Science.gov (United States)

    Narkiewicz; Somers

    1997-10-01

    This review examines the effects of a single bout of exercise and of endurance training on blood pressure in patients with hypertension. Possible autonomic mechanisms that mediate these changes in blood pressure are reviewed briefly. Blood pressure rises during exercise. During the second half hour after exercise blood pressure is lower. This p;ost-exercise reduction in blood pressure is associated with a decrease in muscle sympathetic nerve activity, an increase in baroreflex gain and a reduction in the level of blood pressure (set point) at which baroreflex activation occurs. The post-exercise fall in blood pressure appears to be limited to several hours and is not likely to explain any chronic reduction in blood pressure from endurance training. Endurance training elicits modest (approximately 4-5 mmHg) reductions in blood pressure. Because of the intrinsic variability of blood pressure, the decreases in blood pressure after endurance training is evident, especially when multiple measurements of blood pressure are obtained. Studies using 24 h blood pressure measurements suggest that, although endurance training lowers daytime blood pressure, blood pressure during sleep remains unchanged. The mechanism underlying the reduction in blood pressure in endurance training is not known. Although physical fitness is known to attenuate the sympathetic response to acute exercise, whether resting sympathetic drive is decreased with endurance training remains controversial. The slowing of heart rate that accompanies endurance training is also associated with an increase in variability of heart rate. The slower heart rate, increased variability of heart rate and lower blood pressure after endurance training are accompanied by an increase in baroreflex sensitivity. Even though the antihypertensive effect of endurance training is modest, the favourable effects of physical fitness on other risk factors for cardiovascular disease make exercise training an important approach in

  9. INFLUENCE OF SHOCK VOLTAGE FROM THE ELECTRIC DISCHARGE ON THE FATIGUE ENDURANCE OF CARBON STEEL IN WATER

    Directory of Open Access Journals (Sweden)

    I. O. Vakulenko

    2015-09-01

    Full Text Available Purpose. The research supposes the explanation of influence of stress impulses from an electrical discharge in water on the level of the limited endurance at a cyclic loading of the thermally work-hardened carbon steel. Methodology. Material for research was steel 45 (0,45 % carbon with сoncentration of chemical elements within the limits of steel composition. Specimens for tests are made as plates in 1 thick, width 15 and length 120-180 mm. The structural state of steel corresponded to quenching on a martensite from the normal temperatures of annealing and tempering at 300C, duration of 1 h. Microstructure was investigated with the use of electronic microscopy, the density of dislocations was estimated on the methods of X-ray analysis. Hardness was measured on the method of Rockwell (scale of «C». A cyclic loading was carried out in the conditions of symmetric bend on a tester «Saturn-10» at a temperature +20C. The treatment by shock voltage from the electrical discharge was carried out in water on setting of bath type «Iskra-23», used for cleaning of castings manufactures. Electric impulses were formed at 15-18 kV with energy of 10-12 kJ and amplitude of 1-2 GPа. Findings. As a result of processing pulses of a pressure wave of heat-strengthened steel 45 found the increase of endurance under the cyclic loading corresponds to an increased amount of accumulated dislocations on the fracture surface. The use of Coffin–Manson Equation allowed finding the decrease of deformation per cycle of loading as a result of arising stress from an electrical discharge in water. On the fracture surface (after pulse exposure was found the increased number of dislocations, located in different crystallographic systems, that is a testament to the rather complicated development of dislocation transformations in the structure of steel, which provide an increase of endurance at a fatigue. The increase of the limited endurance became as a result of impulsive

  10. U.S. Coast Guard Guide for the Management of Crew Endurance Risk Factors - Version 1.0

    National Research Council Canada - National Science Library

    Comperatore, Carlos

    2001-01-01

    .... This Guide will show you how to identify and manage crew endurance risk factors. The step-by-step process will guide you in selecting and implementing the controls necessary to improve crew endurance...

  11. Seasonal Variation of Agility, Speed and Endurance Performance in Young Elite Soccer Players

    Directory of Open Access Journals (Sweden)

    Michal Dragijsky

    2017-02-01

    Full Text Available The aim of this study was to investigate changes in the linear running speed (LRS for 30 m, change of direction speed (CODS, and endurance in young elite Czech soccer players. The following tests were conducted to assess CODS and endurance: Agility 505 turning toward the dominant (A505DL and non-dominant lower limb (A505NL; Illinois Agility Test (IAT; and intermittent test (Yo-Yo IRT1. During the soccer season, we investigated performance at the following time periods: the start (t1 and the end of the pre-season period (t2; during (t3 and at the end of the competitive period (t4. Repeated measurement analysis of variance revealed a significant effect of time period on selected fitness parameters (p < 0.05. Post hoc analysis for test A505DL revealed significant improvements of performance at t3 (2.71 ± 0.08 s and t4 (2.72 ± 0.06 s compared to t1 (2.81 ± 0.09 s. A505NL was significantly different between t1 (2.83 ± 0.09 s and t2 (2.76 ± 0.09 s, t3 (2.7 ± 0.07 s and t4 (2.71 ± 0.09 s. Performance of CODS at t1 for the IAT (18.82 ± 0.56 s was significantly lower (p < 0.05 than any other time period (t2 = 18.52 ± 0.63 s, t3 = 17.94 ± 0.51 s, t4 = 17.89 ± 0.66 s. The power of LRS was significantly different at t3 (4.99 ± 0.15 s, and t4 (4.98 ± 0.17 s compared to t1 (5.15 ± 0.21 s, and t2 (5.07 ± 0.14 s. For the Yo-Yo IRT1 test, we observed a significant increase in performance between t1 (625.26 ± 170.34 m, t2 (858.95 ± 210.55 m, and t3 (953.68 ± 229.88 m. These results show the impact of soccer season time period on young soccer player performance and may further serve as a basis for comparison with similar research conducted by peers. These results may aid sports practice for clinicians, conditioning coaches, soccer coaches and physiotherapeutic coaches.

  12. An early and enduring advanced technology originating 71,000 years ago in South Africa.

    Science.gov (United States)

    Brown, Kyle S; Marean, Curtis W; Jacobs, Zenobia; Schoville, Benjamin J; Oestmo, Simen; Fisher, Erich C; Bernatchez, Jocelyn; Karkanas, Panagiotis; Matthews, Thalassa

    2012-11-22

    There is consensus that the modern human lineage appeared in Africa before 100,000 years ago. But there is debate as to when cultural and cognitive characteristics typical of modern humans first appeared, and the role that these had in the expansion of modern humans out of Africa. Scientists rely on symbolically specific proxies, such as artistic expression, to document the origins of complex cognition. Advanced technologies with elaborate chains of production are also proxies, as these often demand high-fidelity transmission and thus language. Some argue that advanced technologies in Africa appear and disappear and thus do not indicate complex cognition exclusive to early modern humans in Africa. The origins of composite tools and advanced projectile weapons figure prominently in modern human evolution research, and the latter have been argued to have been in the exclusive possession of modern humans. Here we describe a previously unrecognized advanced stone tool technology from Pinnacle Point Site 5-6 on the south coast of South Africa, originating approximately 71,000 years ago. This technology is dominated by the production of small bladelets (microliths) primarily from heat-treated stone. There is agreement that microlithic technology was used to create composite tool components as part of advanced projectile weapons. Microliths were common worldwide by the mid-Holocene epoch, but have a patchy pattern of first appearance that is rarely earlier than 40,000 years ago, and were thought to appear briefly between 65,000 and 60,000 years ago in South Africa and then disappear. Our research extends this record to ~71,000 years, shows that microlithic technology originated early in South Africa, evolved over a vast time span (~11,000 years), and was typically coupled to complex heat treatment that persisted for nearly 100,000 years. Advanced technologies in Africa were early and enduring; a small sample of excavated sites in Africa is the best explanation for any

  13. ENHANCE: Design and rationale of a randomized controlled trial for promoting enduring happiness & well-being.

    Science.gov (United States)

    Kushlev, Kostadin; Heintzelman, Samantha J; Lutes, Lesley D; Wirtz, Derrick; Oishi, Shigehiro; Diener, Ed

    2017-01-01

    Individuals who are higher in subjective well-being not only feel happier, they are more likely have fulfilling relationships, increased work performance and income, better physical health, and longer lives. Over the past several decades, the science of subjective well-being has produced insights into these benefits of happiness, and-recognizing their importance-has begun to examine the factors that lead to greater well-being, from cultivating strong relationships to pursuing meaningful goals. However, studies to date have typically focused on improving subjective well-being by intervening with singular constructs, using primarily college student populations, and were short-term in nature. Moreover, little is understood about the impact of a well-being treatment delivered online vs. in-person. In the present article, we describe a comprehensive intervention program including 3-month initial treatment followed by a 3-month follow-up, ENHANCE: Enduring Happiness and Continued Self-Enhancement. One-hundred and sixty participants will be recruited from two different sites to participate in one of two versions of ENHANCE: in-person (n=30) vs. wait-list control (n=30); or online (n=50) vs. wait-list control (n=50). Assessments will be completed at baseline, three months and six months. Our primary outcome is change in subjective well-being across treatment (3months) and follow-up (6months). Secondary outcomes include self-report and objective measures of health, as well as a psychological mediators (e.g., psychological needs) and moderators (e.g., personality) of treatment outcomes. We hope to provide researchers, practitioners, and individuals with an evidence-based treatment to improve happiness and subjective well-being. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Effect of one session endurance exhausting exercise on some coagulation markers of mature and immature wistar rats

    Directory of Open Access Journals (Sweden)

    Shadmehr MirdarHarijani

    2013-06-01

    Full Text Available Background: The incidence of thrombosis is lower in children and prepubertal period than adults. But its incidence increases in adolescence.The aim of this study was comparing the effect of one session of endurance exhaustive exercise in different times on some of coagulation systems markers in pre and after maturation wistar rats. Material and Methods: 27mature male wistar rats with 241±5 grams mean weight and 27 immature male rats with 97±5 grams mean weight which were 14 and 5 weeks old, respectively, after two weeks getting accustomed to the new environment and treadmill, were divided into one control and two exercising groups. Then, sampling was performed immediately and after 24 hours after exercise. Exhausting endurance exercise program involved increasing the speed of treadmill until getting exhausted. Fibrinogen, APTT, and PT were measured with the Clause and coagulation methods. The analysis was performed by using independent t-test, one-way variance analysis and tukey test. Significance level was assigned for all statistical analysis (p≤0.050. Results: Results in immature and mature rats groups indicated that amounts of fibrinogen has had significant reduction immediately after exercise (p=0.004, p=0.047, and 24 hours after exercise were significantly increased only in mature rats (p=0.000. Also, APTT in all groups decreased immediately and 24 hours after exercise but it was significant just 24 hours after exercise. Conclusion: Due to the increased fibrinogen and decreased APTT at 24 hours after exhaustive endurance exercise in mature and immature rats, it seems that performing such activities in children and inactive adults must be accompanied with special considerations.

  15. The Effects of 6 Weeks of Endurance Training and Consumption of Different Doses of Boldenone on Hematological Factors and Spleen Structure Changes in Male Wistar Rats

    Directory of Open Access Journals (Sweden)

    Asieh Abbassi Daloii

    2017-06-01

    Full Text Available Background and Objectives: Regardless of how many periods and how long the androgenic-anabolic steroids have been used, they can cause side effects. The objective of this study was to investigate the effect a 6-week endurance training and using different doses of anabolic steroid boldenone on hematological factors and changes in spleen structure in male Wistar rats. Methods: In this experimental study, 47 male Wistar rats aged 12 weeks, were randomly divided into 7 groups (control, sham, boldenone-1, boldenone-2, endurance training, endurance training+boldenone-1, endurance training+boldenone-2. Increasing endurance training program was performed at the speed of 10-30m/min (Vo2max, 75-80% for 6 weeks and 5 days/week. The drug was injected deeply into the quadriceps and hamstring muscles once a week, on an appointed day. After anesthesia and dissection, the spleen was removed. Finally, the selected microscopic sections, were studied using a light microscope after staining with hematoxylin and eosin. Data were analyzed by dependent t-, one-way ANOVA, and post-hoc LSD tests at α<0.05 level. Results: In this study, boldenone supplementation at different doses led to weight gain, non-significant decrease in spleen weight (p=0.297, increase in white blood cells (p=0.041, and increase in hematocrit level (p=0.017. Also, there was a significant difference between the effect of exercise and boldenone consumption on the extent of damage to white pulp, red pulp, and the spleen sinusoidal space (p=0.001. Conclusion: The findings of this study showed it is likely that short-term consumption of boldenone have negative effects on the spleen structure, followed by negative changes in hematological factors.

  16. CEA (Carcinoembryonic Antigen) Test

    Science.gov (United States)

    ... Gene Mutations Testing Cytomegalovirus (CMV) Tests D-dimer Dengue Fever Testing Des-gamma-carboxy prothrombin (DCP) DHEAS ... Glance Why Get Tested? Primarily to monitor cancer treatment, including response to therapy and recurrence; as an ...

  17. Early Parental Positive Behavior Support and Childhood Adjustment: Addressing Enduring Questions with New Methods.

    Science.gov (United States)

    Waller, Rebecca; Gardner, Frances; Dishion, Thomas; Sitnick, Stephanie L; Shaw, Daniel S; Winter, Charlotte E; Wilson, Melvin

    2015-05-01

    A large literature provides strong empirical support for the influence of parenting on child outcomes. The current study addresses enduring research questions testing the importance of early parenting behavior to children's adjustment. Specifically, we developed and tested a novel multi-method observational measure of parental positive behavior support at age 2. Next, we tested whether early parental positive behavior support was related to child adjustment at school age, within a multi-agent and multi-method measurement approach and design. Observational and parent-reported data from mother-child dyads (N = 731; 49 percent female) were collected from a high-risk sample at age 2. Follow-up data were collected via teacher report and child assessment at age 7.5. The results supported combining three different observational methods to assess positive behavior support at age 2 within a latent factor. Further, parents' observed positive behavior support at age 2 predicted multiple types of teacher-reported and child-assessed problem behavior and competencies at 7.5 years old. Results supported the validity and predictive capability of a multi-method observational measure of parenting and the importance of a continued focus on the early years within preventive interventions.

  18. Comparability and repeatability of three commonly used methods for measuring endurance capacity.

    Science.gov (United States)

    Baxter-Gilbert, James; Mühlenhaupt, Max; Whiting, Martin J

    2017-12-01

    Measures of endurance (time to exhaustion) have been used to address a wide range of questions in ecomorphological and physiological research, as well as being used as a proxy for survival and fitness. Swimming, stationary (circular) track running, and treadmill running are all commonly used methods for measuring endurance. Despite the use of these methods across a broad range of taxa, how comparable these methods are to one another, and whether they are biologically relevant, is rarely examined. We used Australian water dragons (Intellagama lesueurii), a species that is morphologically adept at climbing, swimming, and running, to compare these three methods of endurance and examined if there is repeatability within and between trial methods. We found that time to exhaustion was not highly repeatable within a method, suggesting that single measures or a mean time to exhaustion across trials are not appropriate. Furthermore, we compared mean maximal endurance times among the three methods, and found that the two running methods (i.e., stationary track and treadmill) were similar, but swimming was distinctly different, resulting in lower mean maximal endurance times. Finally, an individual's endurance rank was not repeatable across methods, suggesting that the three endurance trial methods are not providing similar information about an individual's performance capacity. Overall, these results highlight the need to carefully match a measure of performance capacity with the study species and the research questions being asked so that the methods being used are behaviorally, ecologically, and physiologically relevant. © 2018 Wiley Periodicals, Inc.

  19. X-ray and CT signs of connective tissue dysplasia in patients with primarily diagnosed infiltrative pulmonary tuberculosis

    International Nuclear Information System (INIS)

    Sukhanova, L.A.; Sharmazanova, O.P.

    2009-01-01

    The x-ray signs of connective tissue systemic dysplasia (CTSD) in patients with primarily diagnosed pulmonary tuberculosis was investigated. Fifty-four patients (28 med and 26 women aged 18-70) with primarily diagnosed infiltrative pulmonary tuberculosis underwent x-ray study. In patients with infiltration pulmonary tuberculosis CTSD in the lungs manifests by their diminishing, deformity of the lung pattern, high position of the diaphragm cupola, mediastinum shift to the side of the pathology, which is better seen on CT. The degree of CTSD x-ray signs in the lungs depends on the number of phenotypical signs that is the degree of the disease manifestation. CT allows more accurate determining of the signs of connective tissue dysplasia in which tuberculosis develops

  20. Assessment of Vegetation Variation on Primarily Creation Zones of the Dust Storms Around the Euphrates Using Remote Sensing Images

    Directory of Open Access Journals (Sweden)

    Jamil Amanollahi

    2012-06-01

    Full Text Available Recently, period frequency and effect domain of the dust storms that enter Iran from Iraq have increased. In this study, in addition to detecting the creation zones of the dust storms, the effect of vegetation cover variation on their creation was investigated using remote sensing. Moderate resolution image Spectroradiometer (MODIS and Landsat Thematic Mapper (TM5 have been utilized to identify the primarily creation zones of the dust storms and to assess the vegetation cover variation, respectively. Vegetation cover variation was studied using Normalized Differences Vegetation Index (NDVI obtained from band 3 and band 4 of the Landsate satellite. The results showed that the surrounding area of the Euphrates in Syria, the desert in the vicinity of this river in Iraq, including the deserts of Alanbar Province, and the north deserts of Saudi Arabia are the primarily creation zones of the dust storms entering west and south west of Iran. The results of NDVI showed that excluding the deserts in the border of Syria and Iraq, the area with very weak vegetation cover have increased between 2.44% and 20.65% from 1991 to 2009. In the meanwhile, the retention pound surface areas in the south deserts of Syria as well as the deserts in its border with Iraq have decreased 6320 and 4397 hectares, respectively. As it can be concluded from the findings, one of the main environmental parameters initiating these dust storms is the decrease in the vegetation cover in their primarily creation zones.

  1. The Effect of Two Speed Endurance Training Regimes on Performance of Soccer Players.

    Directory of Open Access Journals (Sweden)

    F Marcello Iaia

    Full Text Available In order to better understand the specificity of training adaptations, we compared the effects of two different anaerobic training regimes on various types of soccer-related exercise performances. During the last 3 weeks of the competitive season, thirteen young male professional soccer players (age 18.5±1 yr, height 179.5±6.5 cm, body mass 74.3±6.5 kg reduced the training volume by ~20% and replaced their habitual fitness conditioning work with either speed endurance production (SEP; n = 6 or speed endurance maintenance (SEM; n = 7 training, three times per wk. SEP training consisted of 6-8 reps of 20-s all-out running bouts followed by 2 min of passive recovery, whereas SEM training was characterized by 6-8 x 20-s all-out efforts interspersed with 40 s of passive recovery. SEP training reduced (p<0.01 the total time in a repeated sprint ability test (RSAt by 2.5%. SEM training improved the 200-m sprint performance (from 26.59±0.70 to 26.02±0.62 s, p<0.01 and had a likely beneficial impact on the percentage decrement score of the RSA test (from 4.07±1.28 to 3.55±1.01% but induced a very likely impairment in RSAt (from 83.81±2.37 to 84.65±2.27 s. The distance covered in the Yo-Yo Intermittent Recovery test level 2 was 10.1% (p<0.001 and 3.8% (p<0.05 higher after SEP and SEM training, respectively, with possibly greater improvements following SEP compared to SEM. No differences were observed in the 20- and 40-m sprint performances. In conclusion, these two training strategies target different determinants of soccer-related physical performance. SEP improved repeated sprint and high-intensity intermittent exercise performance, whereas SEM increased muscles' ability to maximize fatigue tolerance and maintain speed development during both repeated all-out and continuous short-duration maximal exercises. These results provide new insight into the precise nature of a stimulus necessary to improve specific types of athletic performance in

  2. The effect of repeated periods of speed endurance training on performance, running economy, and muscle adaptations.

    Science.gov (United States)

    Skovgaard, C; Almquist, N W; Bangsbo, J

    2018-02-01

    The effect of repeated intense training interventions was investigated in eight trained male runners (maximum oxygen uptake [VO 2 -max]: 59.3±3.2 mL/kg/min, mean±SD) who performed 10 speed endurance training (SET; repeated 30-seconds "all-out" bouts) and 10 aerobic moderate-intensity training sessions during two 40-day periods (P1 and P2) separated by ~80 days of habitual training. Before and after both P1 and P2, subjects completed an incremental test to exhaustion to determine VO 2 -max and a repeated running test at 90% vVO 2 -max to exhaustion (RRT) to determine short-term endurance capacity. In addition, running economy (RE) was measured at 60% vVO 2 -max (11.9±0.5 km/h) and v10-km (14.3±0.9 km/h), a 10-km track-running test was performed, and a biopsy from m. vastus lateralis was collected. 10-km performance and VO 2 -max (mL/min) were the same prior to P1 and P2, whereas RE was better (P<.05) before P2 than before P1. During P1 and P2, 10-km performance (2.9% and 2.3%), VO 2 -max (2.1% and 2.6%), and RE (1.9% and 1.8% at 60% vVO 2 -max; 1.6% and 2.0% at v10-km) improved (P<.05) to the same extent, respectively. Performance in RRT was 20% better (P<.05) after compared to before P2, with no change in P1. No changes in muscle expression of Na + ,K + -ATPase α1, α2 and β1, NHE1, SERCA1 and SERCA2, actin, and CaMKII were found during neither P1 nor P2. Thus, the present study demonstrates that a second period of intense training leads to improved short-term performance and further improved RE, whereas 10-km performance and VO 2 -max improve to the same extent as during the first period. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. [Comparison of cardiopulmonary endurance and muscular fitness in teenagers between Hong Kong and inland cities].

    Science.gov (United States)

    Hong, Y; Chan, K; Wang, Y

    1997-01-01

    A study on the data of the physique investigated in teenagers was carried out between Hong Kong and inland cities to compare their cardiopulmonary endurance and muscular fitness. Results revealed that cardiopulmonary endurance in school teenagers of both sex at different ages in inland cities was better than that in Hong Kong. Muscular strength and endurance of sports performance of teenagers, except for standing long jump, in Hong Kong were weaker than that in inland cities. It suggests that attention should be paid to the involvement of teenagers in physical education with the increase of people's living standard.

  4. Effect of a moderate caffeine dose on endurance cycle performance and thermoregulation during prolonged exercise in the heat.

    Science.gov (United States)

    Beaumont, Ross E; James, Lewis J

    2017-11-01

    This study investigated the influence of a moderate caffeine dose on endurance cycle performance and thermoregulation during prolonged exercise in high ambient temperature. Double-blind cross-over study. Eight healthy, recreationally active males (mean±SD; age: 22±1 years; body mass: 71.1±8.5kg; VO 2peak : 55.9±5.8mLkg -1 min -1 ; W max : 318±37W) completed one VO 2peak test, one familiarisation trial and two experimental trials. After an overnight fast, participants ingested a placebo or a 6mgkg -1 caffeine dose 60min before exercise. The exercise protocol consisted of 60min of cycle exercise at 55% W max , followed by a 30min performance task (total kJ produced) in 30°C and 50% RH. Performance was enhanced (Cohen's d effect size=0.22) in the caffeine trial (363.8±47.6kJ) compared with placebo (353.0±49.0kJ; p=0.004). Caffeine did not influence core (p=0.188) or skin temperature (p=0.577) during exercise. Circulating prolactin (p=0.572), cortisol (p=0.842) and the estimated rates of fat (p=0.722) and carbohydrate oxidation (p=0.454) were also similar between trial conditions. Caffeine attenuated perceived exertion during the initial 60min of exercise (p=0.033), with no difference in thermal stress across trials (p=0.911). Supplementation with 6mgkg -1 caffeine improved endurance cycle performance in a warm environment, without differentially influencing thermoregulation during prolonged exercise at a fixed work-rate versus placebo. Therefore, moderate caffeine doses which typically enhance performance in temperate environmental conditions also appear to benefit endurance performance in the heat. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  5. Effect of Progressive Volume-Based Overload During Plyometric Training on Explosive and Endurance Performance in Young Soccer Players.

    Science.gov (United States)

    Ramírez-Campillo, Rodrigo; Henríquez-Olguín, Carlos; Burgos, Carlos; Andrade, David C; Zapata, Daniel; Martínez, Cristian; Álvarez, Cristian; Baez, Eduardo I; Castro-Sepúlveda, Mauricio; Peñailillo, Luis; Izquierdo, Mikel

    2015-07-01

    The purpose of the study was to compare the effects of progressive volume-based overload with constant volume-based overload on muscle explosive and endurance performance adaptations during a biweekly short-term (i.e., 6 weeks) plyometric training intervention in young soccer players. Three groups of young soccer players (age 13.0 ± 2.3 years) were divided into: control (CG; n = 8) and plyometric training with (PPT; n = 8) and without (NPPT; n = 8) a progressive increase in volume (i.e., 16 jumps per leg per week, with an initial volume of 80 jumps per leg each session). Bilateral and unilateral horizontal and vertical countermovement jump with arms (CMJA), 20-cm drop jump reactive strength index (RSI20), maximal kicking velocity (MKV), 10-m sprint, change of direction speed (CODS), and Yo-Yo intermittent recovery level 1 test (Yo-Yo IR1) were measured. Although both experimental groups significantly increased CMJA, RSI20, CODS, and endurance performance, only PPT showed a significant improvement in MKV and 10-m sprint time. In addition, only PPT showed a significantly higher performance improvement in jumping, MKV, and Yo-Yo IR1 compared with CG. Also, PPT showed higher meaningful improvement compared with NPPT in all (except 1) jump performance measures. Furthermore, although PPT involved a higher total volume compared with NPPT, training efficiency (i.e., percentage change in performance/total jump volume) was similar between groups. Our results show that PPT and NPPT ensured significant improvement in muscle explosive and endurance performance measures. However, a progressive increase in plyometric training volume seems more advantageous to induce soccer-specific performance improvements.

  6. Isokinetic and isometric strength-endurance after 6 hours of immersion and 6 degrees head-down tilt in men

    Science.gov (United States)

    Shaffer-Bailey, M.; Greenleaf, J. E.; Hutchinson, T. M.

    1996-01-01

    PURPOSE: To determine weight (water) loss levels for onset of muscular strength and endurance changes during deconditioning. METHODS: Seven men (27-40 yr) performed maximal shoulder-, knee-, and ankle-joint isometric (0 degree.s(-1) load) and isokinetic (60 degrees, 120 degrees, 180 degrees.s(-1) velocity) exercise tests during ambulatory control (AC), after 6 h of 6 degrees head-down tilt (HDT; dry-bulb temp. = 23.2 +/- SD 0.6 degrees C, relative humidity = 31.1+/- 11.1%) and after 6 h of 80 degrees foot-down head-out water immersion (WI; water temp. = 35.0 +/- SD 0.1 degree C) treatments. RESULTS: Weight (water) loss after HDT (1.10 +/- SE 0.14 kg, 1.4 +/- 0.2% body wt) and WI (1.54+/- 0.19 kg, 2.0 +/- 0.2% body wt) were not different, but urinary excretion with WI (1,354 +/- 142 ml.6 h(-1)) was 28% greater (p strength was unchanged except for three knee-joint peak torques: AC torque (120 degrees.s(-1), 285 +/- 20 Nm) decreased to 268 +/- 21 Nm (delta = -6%, p strength and endurance decrements is more than 2% body weight (water) loss, while significant reduction in knee-joint muscular strength-endurance occurred only at moderate (120 degrees.s(-1) and lighter (180 degrees.s(-1)) loads with body weight loss of 1.4-2.0% following WI or HDT, respectively. These weight (water) losses and knee-joint strength decrements are somewhat less than the mean weight loss of 2.6% and knee-joint strength decrements of 6-20% of American astronauts after Skylab flights to 84 d.

  7. The effect of 3 different exercise approaches on neck muscle endurance, kinesiophobia, exercise compliance, and patient satisfaction in chronic whiplash.

    Science.gov (United States)

    Peterson, Gunnel E; Landén Ludvigsson, Maria H; O'Leary, Shaun P; Dedering, Åsa M; Wallman, Thorne; Jönsson, Margaretha I N; Peolsson, Anneli L C

    2015-09-01

    The purpose of this study was to compare the effects of 3 different exercise approaches on neck muscle endurance (NME), kinesiophobia, exercise compliance, and patient satisfaction in patients with chronic whiplash. This prospective randomized clinical trial included 216 individuals with chronic whiplash. Participants were randomized to 1 of 3 exercise interventions: neck-specific exercise (NSE), NSE combined with a behavioral approach (NSEB), or prescribed physical activity (PPA). Measures of ventral and dorsal NME (endurance time in seconds), perceived pain after NME testing, kinesiophobia, exercise compliance, and patient satisfaction were recorded at baseline and at the 3- and 6-month follow-ups. Compared with individuals in the prescribed physical activity group, participants in the NSE and NSEB groups exhibited greater gains in dorsal NME (P = .003), greater reductions in pain after NME testing (P = .03), and more satisfaction with treatment (P .07). Among patients with chronic whiplash, a neck-specific exercise intervention (with or without a behavioral approach) appears to improve NME. Participants were more satisfied with intervention including neck-specific exercises than with the prescription of general exercise. Copyright © 2015 National University of Health Sciences. Published by Elsevier Inc. All rights reserved.

  8. Effects of resistance training on endurance capacity and muscle fiber composition in young top-level cyclists

    DEFF Research Database (Denmark)

    Aagaard, P; Andersen, J L; Bennekou, M

    2011-01-01

    Equivocal findings exist on the effect of concurrent strength (S) and endurance (E) training on endurance performance and muscle morphology. Further, the influence of concurrent SE training on muscle fiber-type composition, vascularization and endurance capacity remains unknown in top......-level endurance athletes. The present study examined the effect of 16 weeks of concurrent SE training on maximal muscle strength (MVC), contractile rate of force development (RFD), muscle fiber morphology and composition, capillarization, aerobic power (VO(2max) ), cycling economy (CE) and long....../short-term endurance capacity in young elite competitive cyclists (n=14). MVC and RFD increased 12-20% with SE (P...

  9. Effects of resistance training on endurance capacity and muscle fiber composition in young top-level cyclists

    DEFF Research Database (Denmark)

    Aagaard, P; Andersen, J L; Bennekou, M

    2011-01-01

    Equivocal findings exist on the effect of concurrent strength (S) and endurance (E) training on endurance performance and muscle morphology. Further, the influence of concurrent SE training on muscle fiber-type composition, vascularization and endurance capacity remains unknown in top......-level endurance athletes. The present study examined the effect of 16 weeks of concurrent SE training on maximal muscle strength (MVC), contractile rate of force development (RFD), muscle fiber morphology and composition, capillarization, aerobic power (VO2max), cycling economy (CE) and long/short-term endurance...... capacity in young elite competitive cyclists (n=14). MVC and RFD increased 12-20% with SE (P...

  10. The Capacity to Endure: Following Nature’s Lead

    Directory of Open Access Journals (Sweden)

    Frank Fogarty

    2013-06-01

    Full Text Available Many businesses today are striving to improve their environmental sustainability for a variety of reasons, ranging from consumer demand for “greener” products to potential cost-savings. For many business decision-makers who lack formal environmental training, the process of identifying facets of their organization that can be improved is unclear and challenging. Inspired by the fields of biomimicry, industrial ecology and organizational ecology, this paper draws on the inherent capacity to endure (CTE of the natural world and recognizes that ecosystem function can be used as a technical advisor to guide business sustainability. We identified major attributes of ecosystems that both contribute to their CTE and can be easily translated into applications for the business world. Each of these attributes (fitness, functional redundancy, keystone species, waste and efficiency and their applications are discussed at length. While further work is needed to evaluate their effectiveness and appropriateness for individual firms, we hope they can serve as a starting point for businesses seeking to improve their environmental sustainability.

  11. Transference of kettlebell training to strength, power, and endurance.

    Science.gov (United States)

    Manocchia, Pasquale; Spierer, David K; Lufkin, Adrienne K S; Minichiello, Jacqueline; Castro, Jessica

    2013-02-01

    Kettlebells are a popular implement in many strength and conditioning programs, and their benefits are touted in popular literature, books, and videos. However, clinical data on their efficacy are limited. The purpose of this study was to examine whether kettlebell training transfers strength and power to weightlifting and powerlifting exercises and improves muscular endurance. Thirty-seven subjects were assigned to an experimental (EXP, n = 23; mean age = 40.9 ± 12.9 years) or a control group (CON; n = 14; mean age = 39.6 ± 15.8 years), range 18-72 years. The participants were required to perform assessments including a barbell clean and jerk, barbell bench press, maximal vertical jump, and 45° back extensions to volitional fatigue before and after a 10-week kettlebell training program. Training was structured in a group setting for 2 d·wk(-1) for 10 weeks. A repeated measures analysis of variance was conducted to determine group × time interactions and main effects. Post hoc pairwise comparisons were conducted when appropriate. Bench press revealed a time × group interaction and a main effect (p power and strength in response to 10 weeks of training with kettlebells. Traditional training methods may not be convenient or accessible for strength and conditioning specialists, athletes, coaches, and recreational exercisers. The current data suggest that kettlebells may be an effective alternative tool to improve performance in weightlifting and powerlifting.

  12. Hypoxic training methods for improving endurance exercise performance

    Directory of Open Access Journals (Sweden)

    Jacob A. Sinex

    2015-12-01

    Full Text Available Endurance athletic performance is highly related to a number of factors that can be altered through altitude and hypoxic training including increases in erythrocyte volume, maximal aerobic exercise capacity, capillary density, and economy. Physiological adaptations in response to acute and chronic exposure to hypoxic environments are well documented and range from short-term detrimental effects to longer-term adaptations that can improve performance at altitude and in sea-level competitions. Many altitude and hypoxic training protocols have been developed, employing various combinations of living and training at sea-level, low, moderate, and high altitudes and utilizing natural and artificial altitudes, with varying degrees of effectiveness. Several factors have been identified that are associated with individual responses to hypoxic training, and techniques for identifying those athletes most likely to benefit from hypoxic training continue to be investigated. Exposure to sufficiently high altitude (2000–3000 m for more than 12 h/day, while training at lower altitudes, for a minimum of 21 days is recommended. Timing of altitude training related to competition remains under debate, although general recommendations can be considered.

  13. Color View of a 'Rat' Hole Trail Inside 'Endurance'

    Science.gov (United States)

    2004-01-01

    This view from the Mars Exploration Rover Opportunity's panoramic camera is an approximately true color rendering of the first seven holes that the rover's rock abrasion tool dug on the inner slope of 'Endurance Crater.' The rover was about 12 meters (about 39 feet) down into the crater when it acquired the images combined into this mosaic. The view is looking back toward the rim of the crater, with the rover's tracks visible. The tailings around the holes drilled by the rock abrasion tool, or 'Rat,' show evidence for fine-grained red hematite similar to what was observed months earlier in 'Eagle Crater' outcrop holes. Starting from the uppermost pictured (closest to the crater rim) to the lowest, the rock abrasion tool hole targets are called 'Tennessee,' 'Cobblehill,' 'Virginia,' 'London,' 'Grindstone,' 'Kettlestone,' and 'Drammensfjorden.' Opportunity drilled these holes on sols 138 (June 13, 2004), 143 (June 18), 145 (June 20), 148 (June 23), 151 (June 26), 153 (June 28) and 161 (July 7), respectively. Each hole is 4.5 centimeters (1.8 inches) in diameter. This image was generated using the panoramic camera's 750-, 530-, and 430-nanometer filters. It was taken on sol 173 (July 19).

  14. Improvement of Endurance of DMD Animal Model Using Natural Polyphenols

    Directory of Open Access Journals (Sweden)

    Clementina Sitzia

    2015-01-01

    Full Text Available Duchenne muscular dystrophy (DMD, the most common form of muscular dystrophy, is characterized by muscular wasting caused by dystrophin deficiency that ultimately ends in force reduction and premature death. In addition to primary genetic defect, several mechanisms contribute to DMD pathogenesis. Recently, antioxidant supplementation was shown to be effective in the treatment of multiple diseases including muscular dystrophy. Different mechanisms were hypothesized such as reduced hydroxyl radicals, nuclear factor-κB deactivation, and NO protection from inactivation. Following these promising evidences, we investigated the effect of the administration of a mix of dietary natural polyphenols (ProAbe on dystrophic mdx mice in terms of muscular architecture and functionality. We observed a reduction of muscle fibrosis deposition and myofiber necrosis together with an amelioration of vascularization. More importantly, the recovery of the morphological features of dystrophic muscle leads to an improvement of the endurance of treated dystrophic mice. Our data confirmed that ProAbe-based diet may represent a strategy to coadjuvate the treatment of DMD.

  15. Endurance and failure characteristics of modified Vasco X-2, CBS 600 and AISI 9310 spur gears. [aircraft construction materials

    Science.gov (United States)

    Townsend, D. P.; Zaretsky, E. V.

    1980-01-01

    Gear endurance tests and rolling-element fatigue tests were conducted to compare the performance of spur gears made from AISI 9310, CBS 600 and modified Vasco X-2 and to compare the pitting fatigue lives of these three materials. Gears manufactured from CBS 600 exhibited lives longer than those manufactured from AISI 9310. However, rolling-element fatigue tests resulted in statistically equivalent lives. Modified Vasco X-2 exhibited statistically equivalent lives to AISI 9310. CBS 600 and modified Vasco X-2 gears exhibited the potential of tooth fracture occurring at a tooth surface fatigue pit. Case carburization of all gear surfaces for the modified Vasco X-2 gears results in fracture at the tips of the gears.

  16. The Clinical and Nonclinical Values of Nonexercise Estimation of Cardiovascular Endurance in Young Asymptomatic Individuals

    Directory of Open Access Journals (Sweden)

    Mahmoud A. Alomari

    2012-01-01

    Full Text Available Exercise testing is associated with barriers prevent using cardiovascular (CV endurance (CVE measure frequently. A recent nonexercise model (NM is alleged to estimate CVE without exercise. This study examined CVE relationships, using the NM model, with measures of obesity, physical fitness (PF, blood glucose and lipid, and circulation in 188 asymptomatic young (18–40 years adults. Estimated CVE correlated favorably with measures of PF (r=0.4-0.5 including handgrip strength, distance in 6 munities walking test, and shoulder press, and leg extension strengths, obesity (r=0.2-0.7 including % body fat, body water content, fat mass, muscle mass, BMI, waist and hip circumferences and waist/hip ratio, and circulation (r=0.2-0.3 including blood pressures, blood flow, vascular resistance, and blood (r=0.2-0.5 profile including glucose, total cholesterol, LDL-C, HDL-C, and triglycerides. Additionally, differences (P<0.05 in examined measures were found between the high, average, and low estimated CVE groups. Obviously the majority of these measures are CV disease risk factors and metabolic syndrome components. These results enhance the NM scientific value, and thus, can be further used in clinical and nonclinical settings.

  17. Development of the Main Wing Structure of a High Altitude Long Endurance UAV

    Science.gov (United States)

    Park, Sang Wook; Shin, Jeong Woo; Kim, Tae-Uk

    2018-04-01

    To enhance the flight endurance of a HALE UAV, the main wing of the UAV should have a high aspect ratio and low structural weight. Since a main wing constructed with the thin walled and slender components needed for low structural weight can suffer catastrophic failure during flight, it is important to develop a light-weight airframe without sacrificing structural integrity. In this paper, the design of the main wing of the HALE UAV was conducted using spars which were composed of a carbon-epoxy cylindrical tube and bulkheads to achieve both the weight reduction and structural integrity. The spars were sized using numerical analysis considering non-linear deformation under bending moment. Static strength testing of the wing was conducted under the most critical load condition. Then, the experimental results obtained for the wing were compared to the analytical result from the non-linear finite-element analysis. It was found that the developed main wing reduced its structural weight without any failure under the ultimate load condition of the static strength testing.

  18. A combination of routine blood analytes predicts fitness decrement in elderly endurance athletes.

    Directory of Open Access Journals (Sweden)

    Helmuth Haslacher

    Full Text Available Endurance sports are enjoying greater popularity, particularly among new target groups such as the elderly. Predictors of future physical capacities providing a basis for training adaptations are in high demand. We therefore aimed to estimate the future physical performance of elderly marathoners (runners/bicyclists using a set of easily accessible standard laboratory parameters. To this end, 47 elderly marathon athletes underwent physical examinations including bicycle ergometry and a blood draw at baseline and after a three-year follow-up period. In order to compile a statistical model containing baseline laboratory results allowing prediction of follow-up ergometry performance, the cohort was subgrouped into a model training (n = 25 and a test sample (n = 22. The model containing significant predictors in univariate analysis (alanine aminotransferase, urea, folic acid, myeloperoxidase and total cholesterol presented with high statistical significance and excellent goodness of fit (R2 = 0.789, ROC-AUC = 0.951±0.050 in the model training sample and was validated in the test sample (ROC-AUC = 0.786±0.098. Our results suggest that standard laboratory parameters could be particularly useful for predicting future physical capacity in elderly marathoners. It hence merits further research whether these conclusions can be translated to other disciplines or age groups.

  19. Deep Neck Flexor Endurance in the Adolescent and Young Adult: Normative Data and Associated Attributes.

    Science.gov (United States)

    Jarman, Nathan F; Brooks, Toby; James, C Roger; Hooper, Troy; Wilhelm, Mark; Brismée, Jean-Michel; Domenech, Manuel A; Kotara, Stanley J; Sizer, Phillip S

    2017-10-01

    Deep neck flexor (DNF) muscles stabilize the neck and contribute to head acceleration control. The function of DNF in cervical spine dynamic stabilization has not been examined in athletes of any age group, including adolescents. This investigation was necessary prior to studying the DNF muscles' role in cervical spine injury patterns. The objectives of this study were (1) to determine average Deep Neck Flexor Endurance Test (DNFET) time scores in high school-aged and university-aged subjects (aged 14-22 years); and (2) to establish the relationship between gender and age for adolescent DNFET time scores. Cross-sectional design. Public high school and private university. A total of 81 (40 male, 41 female) healthy high school and collegiate athletes. DNFET time scores (in seconds) were collected and means values were calculated. Interrater reliability was established using the first 15 university-aged subjects enrolled in the study. Mean DNFET time (seconds) scores. The DNF muscle endurance interrater reliability coefficient of reproducibility for 4 allied health clinicians was intraclass correlation coefficient (2,4) 0.712 (confidence interval, 0.24-0.85). The mean (± standard deviation) DNFET time score for females was 31.86 (±8.53) seconds versus 35.57 (±10.43) seconds for males. The DNFET performance demonstrated a significant but fair correlation with age (r = 0.401, P = .0001). No significant performance differences were found between male and female subjects in the 14- to 17-year-old group (U = 187.0, P = .285), the 18- to 22-year-old group (U = 145.0, P = .215), or the total male versus female subject groups (U = 653.0, P = .083). Our study establishes a normative data set available for the DNFET in the adolescent population. The fair correlation between DNFET time scores and age is consistent with other studies. These findings serve as a basis for clinician testing, objectifying, and monitoring DNF dysfunction in an adolescent athletic population. II

  20. Effect and mechanism of micronutrient compound on swimming endurance in mice with nutritional deficiency

    Directory of Open Access Journals (Sweden)

    Jian-quan WU

    2012-07-01

    Full Text Available Objective To investigate the anti-fatigue effect and possible mechanisms of micronutrient compound. Methods One hundred and twenty-five male Kunming mice (SPF were fed following different feeding stuffs: sufficient feed, i.e. AIN-93M feed (corn starch 46.6%, casein 14%, dextrinized corn starch 15.5%, sucrose 10%, soybean oil 4%, fiber 5%, mineral mix 3.5%, vitamin mix 1%, L-cystine 0.18%, choline chloride 0.138% and tert-butylhydroquinone 8 ppm; insufficient feed (composed the same ingredients as the AIN-93M diet, replacing 30%, 50% or 70% of the content of mineral and vitamin mix with corn starch; compound micronutrient-added feed (CMAF, replacing 30% of the content of mineral and vitamin mix of AIN-93M diet with micronutrient compound composed of (g/kg Vit A 0.25, Vit B1 0.3, Vit B2 0.3, Vit B6 0.35, nicotinic acid 1.5, Vit D 0.05, Vit C 50, Vit E 10, calcium carbonate 180, ferrous glycine 1, zinc lactate 1 and corn starch 755.25. The mice were fed for 14 or 28 d, and then subjected to forced swim test with a load on their tails to exhaustion. The maximal swimming time was recorded. In another experiment, the Kunming mice were fed with corresponding feed for 28 d, and then subjected to forced swim test for 60 min, thereafter the samples of blood and liver were collected immediately. The serum contents of glucose, lactate, nonprotein nitrogen, nonesterified fatty acids and hepatic glycogen were measured. Results The dietary intake of 30% nutritional insufficient group (30% group was significantly decreased compared with normal control group (fed with AIN-93M diet, (P 0.05. The serum glucose and hepatic glycogen decreased and serum lactate, nonprotein nitrogen and nonesterified fatty acids increased in the control group, which were aggravated in nutrient insufficient group and reversed in micronutrient supplementation group. Conclusions Insufficient intake of micronutrients has significant influence on swimming endurance in mice and compound

  1. Triacilglicerol intramuscular: um importante substrato energético para o exercício de endurance Triacilglicerol intramuscular: un importante substrato energético para el ejercicio de endurance Intramuscular triacylglycerol: an important energetic substrate for endurance exercise

    Directory of Open Access Journals (Sweden)

    Mônica Aparecida Belmonte

    2005-04-01

    Full Text Available Os ácidos graxos são uma importante fonte de energia para exercício de endurance. Os ácidos graxos plasmáticos encontram-se disponíveis para as fibras musculares sob a forma de ácidos graxos associados à albumina ou agregados à molécula de triacilglicerol (TAG encontrada nas lipoproteínas. Entretanto, além dessas fontes plasmáticas, a hidrólise do TAG encontrado no músculo também pode contribuir com a oferta de ácidos graxos durante o exercício de endurance. O objetivo do presente trabalho foi realizar uma extensa revisão da literatura sobre a importância do TAG intramuscular como substrato energético. A revisão da literatura sugere que a contribuição dos estoques endógenos de TAG durante a realização do exercício de endurance é bastante relevante. Além disso, pode-se concluir que uma adaptação induzida pelo treinamento de endurance é o aumento dos estoques intramusculares de TAG. Após o treinamento de endurance, também é observado aumento na capacidade de utilização desses estoques. Apesar de parecer importante, a contribuição do TAG intramuscular ainda é motivo de controvérsia na literatura. Essa discrepância de resultados está relacionada às metodologias empregadas para estimar a sua oxidação no exercício. A fim de esgotar este assunto de maneira apropriada, mais pesquisas, com novos métodos (ex.: utilização de isótopos, ressonância magnética nuclear e microscopia eletrônica, precisam ser conduzidas.Los ácidos grasos son una fuente importante de energía para el ejercicio de endurance. Los ácidos grasos plasmáticos se encuentran disponibles en las fibras musculares bajo la forma de ácido graso asociado a la albúmina o agregados a la molécula del triacilglicerol (TAG encontrados en las lipoproteínas. Sin embargo, además de estos fuentes plasmáticas, la hidrólisis de los TAG encontrados en el músculo pueden contribuir también con la oferta de ácidos grasos durante el ejercicio

  2. Unmanned Aerial Vehicles: Progress Toward Meeting High Altitude Endurance Aircraft Price Goals

    National Research Council Canada - National Science Library

    1998-01-01

    ...) High Altitude Endurance (HAE) Unmanned Aerial Vehicle (UAV) program to determine whether the average flyaway cost for the Global Hawk and DarkStar HAE alr vehicles will be within DOD's cost goal...

  3. Genome-wide association study identifies three novel genetic markers associated with elite endurance performance

    DEFF Research Database (Denmark)

    Ahmetov, Ii; Kulemin, Na; Popov, Dv

    2015-01-01

    To investigate the association between multiple single-nucleotide polymorphisms (SNPs), aerobic performance and elite endurance athlete status in Russians. By using GWAS approach, we examined the association between 1,140,419 SNPs and relative maximal oxygen consumption rate ([Formula: see text]O2......max) in 80 international-level Russian endurance athletes (46 males and 34 females). To validate obtained results, we further performed case-control studies by comparing the frequencies of the most significant SNPs (with P endurance athletes and opposite cohorts (192...... Russian controls, 1367 European controls, and 230 Russian power athletes). Initially, six 'endurance alleles' were identified showing discrete associations with [Formula: see text]O2max both in males and females. Next, case-control studies resulted in remaining three SNPs (NFIA-AS2 rs1572312, TSHR rs...

  4. Relation between body mass index percentile and muscle strength and endurance

    Directory of Open Access Journals (Sweden)

    Noha Abdel Kader Abdel Kader Hasan

    2016-10-01

    Conclusion: The study shows that the BMI of children had a positive correlation with the muscle strength of quadriceps, triceps, and abdominal muscles while a negative correlation with the endurance time of these muscles.

  5. Glycogen availability and skeletal muscle adaptations with endurance and resistance exercise

    NARCIS (Netherlands)

    Knuiman, Pim; Hopman, Maria T.E.; Mensink, Marco

    2015-01-01

    It is well established that glycogen depletion affects endurance exercise performance negatively. Moreover, numerous studies have demonstrated that post-exercise carbohydrate ingestion improves exercise recovery by increasing glycogen resynthesis. However, recent research into the effects of

  6. Urine concentrations of oral salbutamol in samples collected after intense exercise in endurance athletes

    DEFF Research Database (Denmark)

    Hostrup, Morten; Kalsen, Anders; Auchenberg, Michael

    2014-01-01

    Our objective was to investigate urine concentrations of 8 mg oral salbutamol in samples collected after intense exercise in endurance athletes. Nine male endurance athletes with a VO2max of 70.2 ± 5.9 mL/min/kg (mean ± SD) took part in the study. Two hours after administration of 8 mg oral...

  7. Getting it Right: The Endurance of Improvised Explosive Device Education in the US Army

    Science.gov (United States)

    2017-05-25

    NCO leadership and education was critical to success. This was especially true in divisional engineer units where squad operations in support of...Getting it Right: The Endurance of Improvised Explosive Device Education in the US Army A Monograph by MAJ Christian R. Johnson United States...Endurance of Improvised Explosive Device Education in the US Army 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S

  8. 14 CFR 33.43 - Vibration test.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Vibration test. 33.43 Section 33.43... STANDARDS: AIRCRAFT ENGINES Block Tests; Reciprocating Aircraft Engines § 33.43 Vibration test. (a) Each... configuration of the propeller type which is used for the endurance test, and using, for other engines, the same...

  9. Adaptive characteristics of main muscular groups’ static endurance in 6 years children in initial school period

    Directory of Open Access Journals (Sweden)

    S.V. Bondarenko

    2017-08-01

    Full Text Available Purpose: to study adaptation of 6 years children’s muscular skeletal apparatus to learning work by indicators of static endurance dynamic. Material: in the research 6 years children participated (n=64, boys - n=36, girls- n=28. Indicators of main muscular groups’ static endurance were studied. Results: we determined comparative topography of 13 muscular groups’ static endurance and substantial sex dimorphism was found. In 9 muscular groups the boys advantage was 11.7 - 50.2% (р < 0.05 ÷ 0.01. The level and correlation of muscles-antagonists’ static endurance from the point of evolutionary and ontogeny development of muscular-skeletal apparatus were substantiated. At the end of semester we found significant (р < 0.001 reduction of static endurance indicators as well as the fact that torso muscles were the most sensitive to influence of learning work’s static component. The level of static endurance weakening, under which syndrome of static over-tension appears, was determined. Conclusions: the research results permit to balance the volumes of learning load at initial stage of school work. Organizational-methodic principles of learning and physical education system for children shall be oriented on overcoming muscular-skeletal apparatus’s dysfunctions.

  10. FADD Expression as a Prognosticator in Early-Stage Glottic Squamous Cell Carcinoma of the Larynx Treated Primarily With Radiotherapy

    International Nuclear Information System (INIS)

    Schrijvers, Michiel L.; Pattje, Wouter J.; Slagter-Menkema, Lorian; Mastik, Mirjam F.; Gibcus, Johan H.; Langendijk, Johannes A.; Wal, Jacqueline E. van der; Laan, Bernard F.A.M. vn der; Schuuring, E.

    2012-01-01

    Purpose: We recently reported on the identification of the Fas-associated death domain (FADD) as a possible driver of the chromosome 11q13 amplicon and the association between increased FADD expression and disease-specific survival in advanced-stage laryngeal carcinoma. The aim of this study was to examine whether expression of FADD and its Ser194-phosphorylated isoform (pFADD) predicts local control in patients with early-stage glottic carcinoma primarily treated with radiotherapy only. Methods and Materials: Immunohistochemical staining for FADD and pFADD was performed on pretreatment biopsy specimens of 92 patients with T1–T2 glottic squamous cell carcinoma primarily treated with radiotherapy between 1996 and 2005. Cox regression analysis was used to correlate expression levels with local control. Results: High levels of pFADD were associated with significantly better local control (hazard ratio, 2.40; 95% confidence interval, 1.04–5.55; p = 0.040). FADD overexpression showed a trend toward better local control (hazard ratio, 3.656; 95% confidence interval, 0.853–15.663; p = 0.081). Multivariate Cox regression analysis showed that high pFADD expression was the best predictor of local control after radiotherapy. Conclusions: This study showed that expression of phosphorylated FADD is a new prognostic biomarker for better local control after radiotherapy in patients with early-stage glottic carcinomas.

  11. Effects of Low Versus Moderate Glycemic Index Diets on Aerobic Capacity in Endurance Runners: Three-Week Randomized Controlled Crossover Trial

    Directory of Open Access Journals (Sweden)

    Krzysztof Durkalec-Michalski

    2018-03-01

    Full Text Available The glycemic index (GI of ingested carbohydrates may influence substrate oxidation during exercise and athletic performance. Therefore, the aim of this study was to assess the effect of low- and moderate-GI three-week diets on aerobic capacity and endurance performance in runners. We conducted a randomized crossover feeding study of matched diets differing only in GI (low vs. moderate in 21 endurance-trained runners. Each participant consumed both, low- (LGI and moderate-GI (MGI high-carbohydrate (~60% and nutrient-balanced diets for three weeks each. At the beginning and end of each diet, participants had their aerobic capacity and body composition measured and performed a 12-min running test. After LGI, time to exhaustion during incremental cycling test (ICT and distance covered in the 12-min run were significantly increased. The MGI diet led to an increase in maximal oxygen uptake ( V ˙ O2max, but no performance benefits were found after the MGI diet. The LGI and MGI diets improved time and workload at gas exchange threshold (GET during ICT. The results indicate that a three-week high-carbohydrate LGI diet resulted in a small but significant improvement in athletic performance in endurance runners. Observed increase in V ˙ O2max on MGI diet did not affect performance.

  12. Remembering Hemingway: The Endurance of the Hemingway Myth

    Directory of Open Access Journals (Sweden)

    Lyons Siobhan

    2014-11-01

    Full Text Available Consumers of culture can often view history subjectively, perceiving people and events through an idealistic memory to satisfy their perception of ‘great’, heroic people. The image of American writer Ernest Hemingway was partly created by favorable media imagery and celebrity culture. With the advent of newer media technologies in the twentieth century, writers such as Hemingway, James Joyce, Gertrude Stein, F. Scott Fitzgerald, Emile Zola and Ford Maddox Ford (often called the Lost Generation [generation perdue] were able to carefully manipulate their audience through their writing and the Romantic image that was circulated by the public. The idealized way in which these authors were viewed is reminiscent of the period of Romanticism, when authors such as Jean-Jacques Rousseau and Lord Byron were revered as geniuses. Through films such as Woody Allen’s Midnight in Paris (2011, the Hemingway Myth – in which various attributes and details about the author were exaggerated to fuel Hemingway’s image – has endured well into the twenty-first century. This paper will examine the progress and transformation of the Hemingway Myth, i.e., how it contradicted the man himself. Cultural memory is especially fostered through literature and film, and Allen’s film, along with the 2012 Hemingway and Gellhorn, not only aids this image, of Hemingway as a passionate, romantic gentleman, but it greatly embellishes it. Hemingway’s own works, moreover, facilitated the romanticized manner in which he was received by his public, only later to be solidified in his appearances in various American magazines. This paper will argue that in the field of literature, celebrity authors particularly benefit from the flattering outcome of cultural memory, in which figures such as writers and artists are enamored by their public. By existing in an overwhelmingly artistic industry, it is no surprise that the memory many of these writers leave behind, to this very

  13. Carbohydrate Electrolyte Solutions Enhance Endurance Capacity in Active Females

    Directory of Open Access Journals (Sweden)

    Feng-Hua Sun

    2015-05-01

    Full Text Available The purpose of the present study was to investigate the effects of supplementation with a carbohydrate-electrolyte solution (CES in active females during a prolonged session of submaximal running to exhaustion. Eight healthy active females volunteered to perform a session of open-ended running to exhaustion at 70% of their maximal oxygen consumption on a treadmill during the follicular phase of their menstrual cycle on two occasions. During each run, the subjects consumed either 3mL·kg−1 body mass of a 6% CES or a placebo drink (PL every 20 min during exercise. The trials were administered in a randomized double-blind, cross-over design. During the run, the subjects ingested similar volumes of fluid in two trials (CES: 644 ± 75 mL vs. PL: 593 ± 66 mL, p > 0.05. The time to exhaustion was 16% longer during the CES trial (106.2 ± 9.4 min than during the PL trial (91.6 ± 5.9 min (p < 0.05. At 45 min during exercise, the plasma glucose concentration in the CES trial was higher than that in PL trial. No differences were observed in the plasma lactate level, respiratory exchange ratio, heart rate, perceived rate of exertion, sensation of thirst, or abdominal discomfort between the two trials (p > 0.05. The results of the present study confirm that CES supplementation improves the moderate intensity endurance capacity of active females during the follicular phases of the menstrual cycle. However, the exogenous oxidation of carbohydrate does not seem to explain the improved capacity after CES supplementation.

  14. Caffeine withdrawal and high-intensity endurance cycling performance.

    Science.gov (United States)

    Irwin, Christopher; Desbrow, Ben; Ellis, Aleisha; O'Keeffe, Brooke; Grant, Gary; Leveritt, Michael

    2011-03-01

    In this study, we investigated the impact of a controlled 4-day caffeine withdrawal period on the effect of an acute caffeine dose on endurance exercise performance. Twelve well-trained and familiarized male cyclists, who were caffeine consumers (from coffee and a range of other sources), were recruited for the study. A double-blind placebo-controlled cross-over design was employed, involving four experimental trials. Participants abstained from dietary caffeine sources for 4 days before the trials and ingested capsules (one in the morning and one in the afternoon) containing either placebo or caffeine (1.5 mg · kg(-1) body weight · day(-1)). On day 5, capsules containing placebo or caffeine (3 mg · kg(-1) body weight) were ingested 90 min before completing a time trial, equivalent to one hour of cycling at 75% peak sustainable power output. Hence the study was designed to incorporate placebo-placebo, placebo-caffeine, caffeine-placebo, and caffeine-caffeine conditions. Performance time was significantly improved after acute caffeine ingestion by 1:49 ± 1:41 min (3.0%, P = 0.021) following a withdrawal period (placebo-placebo vs. placebo-caffeine), and by 2:07 ± 1:28 min (3.6%, P = 0.002) following the non-withdrawal period (caffeine-placebo vs. caffeine-caffeine). No significant difference was detected between the two acute caffeine trials (placebo-caffeine vs. caffeine-caffeine). Average heart rate throughout exercise was significantly higher following acute caffeine administration compared with placebo. No differences were observed in ratings of perceived exertion between trials. A 3 mg · kg(-1) dose of caffeine significantly improves exercise performance irrespective of whether a 4-day withdrawal period is imposed on habitual caffeine users.

  15. Range and Endurance Tradeoffs on Personal Rotorcraft Design

    Science.gov (United States)

    Snyder, Christopher A.

    2016-01-01

    Rotorcraft design has always been a challenging tradeoff among overall size, capabilities, complexity, and other factors based on available technology and customer requirements. Advancements in propulsion, energy systems and other technologies have enabled new vehicles and missions; complementary advances in analysis methods and tools enable exploration of these enhanced vehicles and the evolving mission design space. A system study was performed to better understand the interdependency between vehicle design and propulsion system capabilities versus hover / loiter requirements and range capability. Three representative vertical lift vehicles were developed to explore the tradeoff in capability between hover efficiency versus range and endurance capability. The vehicles were a single-main rotor helicopter, a tilt rotor, and a vertical take-off and landing (VTOL) aircraft. Vehicle capability was limited to two or three people (including pilot or crew) and maximum range within one hour of flight (100-200 miles, depending on vehicle). Two types of propulsion and energy storage systems were used in this study. First was traditional hydrocarbon-fueled cycles (such as Otto, diesel or gas turbine cycles). Second was an all-electric system using electric motors, power management and distribution, assuming batteries for energy storage, with the possibility of hydrocarbon-fueled range extenders. The high power requirements for hover significantly reduced mission radius capability. Loiter was less power intensive, resulting in about 1/2 the equivalent mission radius penalty. With so many design variables, the VTOL aircraft has the potential to perform well for a variety of missions. This vehicle is a good candidate for additional study; component model development is also required to adequately assess performance over the design space of interest.

  16. Tocotrienols and Whey Protein Isolates Substantially Increase Exercise Endurance Capacity in Diet -Induced Obese Male Sprague-Dawley Rats

    Science.gov (United States)

    Aguila, Jay; McConell, Glenn K.; McAinch, Andrew J.; Mathai, Michael L.

    2016-01-01

    Background and Aims Obesity and impairments in metabolic health are associated with reductions in exercise capacity. Both whey protein isolates (WPIs) and vitamin E tocotrienols (TCTs) exert favorable effects on obesity-related metabolic parameters. This research sought to determine whether these supplements improved exercise capacity and increased glucose tolerance in diet-induced obese rats. Methods Six week old male rats (n = 35) weighing 187 ± 32g were allocated to either: Control (n = 9), TCT (n = 9), WPI (n = 8) or TCT + WPI (n = 9) and placed on a high-fat diet (40% of energy from fat) for 10 weeks. Animals received 50mg/kg body weight and 8% of total energy intake per day of TCTs and/or WPIs respectively. Food intake, body composition, glucose tolerance, insulin sensitivity, exercise capacity, skeletal muscle glycogen content and oxidative enzyme activity were determined. Results Both TCT and WPI groups ran >50% longer (2271 ± 185m and 2195 ± 265m respectively) than the Control group (1428 ± 139m) during the run to exhaustion test (Pexercise endurance (2068 ± 104m). WPIs increased the maximum in vitro activity of beta-hydroxyacyl-CoA in the soleus muscle (Pexercise endurance by 50% in sedentary, diet-induced obese rats. These positive effects of TCTs and WPIs were independent of body weight, adiposity or glucose tolerance. PMID:27058737

  17. Sympatho-adrenergic activation by endurance exercise: Effect on metanephrines spillover and its role in predicting athlete's performance.

    Science.gov (United States)

    Danese, Elisa; Tarperi, Cantor; Salvagno, Gian Luca; Guzzo, Alessandra; Sanchis-Gomar, Fabian; Festa, Luca; Bertinato, Luciano; Montagnana, Martina; Schena, Federico; Lippi, Giuseppe

    2018-03-20

    The sympatho-adrenergic activation during exercise is implicated in many cardiovascular respiratory and metabolic adaptations which have been thought to partially explain the different levels of performance observed between trained and untrained subjects. To date, no evidence exists about the association between competition performance and markers of "acute stress response". We designed this study to investigate; (i) the acute sympatho-adrenergic activation during endurance exercise in recreational runners by measuring plasma levels of free metanephrine (MN) and normethanephrine (NMN) before and after a half-marathon run; (ii) the association between the metanephrines levels and the running time. 26 amateur runners (15 males, 11 females) aged 30 to 63 years were enrolled. The quantification of MN and NMN was performed by LC-MS/MS. Anthropometric ergonomic and routine laboratory data were recorded. Statistical analyses included paired T -test, univariate and multivariate regressions. The post-run values of MN and NMN displayed a nearly 3.5 and 7 fold increase respectively compared to the baseline values ( p performance. No correlations were found for MN values. NMN is a reliable marker of sympatho-adrenergic activation by exercise and can predict endurance performance in the individual athlete. Adaptation phenomenon occurring not only in the adrenal medulla might represent the biological mechanism underlying this association. Further studies on sympatho-adrenergic activation, competition performance and training status should contemplate the measurement of these metabolites instead of their unstable precursors.

  18. Cardiorespiratory Fitness and Peak Torque Differences between Vegetarian and Omnivore Endurance Athletes: A Cross-Sectional Study.

    Science.gov (United States)

    Lynch, Heidi M; Wharton, Christopher M; Johnston, Carol S

    2016-11-15

    In spite of well-documented health benefits of vegetarian diets, less is known regarding the effects of these diets on athletic performance. In this cross-sectional study, we compared elite vegetarian and omnivore adult endurance athletes for maximal oxygen uptake (VO2 max) and strength. Twenty-seven vegetarian (VEG) and 43 omnivore (OMN) athletes were evaluated using VO2 max testing on the treadmill, and strength assessment using a dynamometer to determine peak torque for leg extensions. Dietary data were assessed using detailed seven-day food logs. Although total protein intake was lower among vegetarians in comparison to omnivores, protein intake as a function of body mass did not differ by group (1.2 ± 0.3 and 1.4 ± 0.5 g/kg body mass for VEG and OMN respectively, p = 0.220). VO2 max differed for females by diet group (53.0 ± 6.9 and 47.1 ± 8.6 mL/kg/min for VEG and OMN respectively, p vegetarian endurance athletes' cardiorespiratory fitness was greater than that for their omnivorous counterparts, but that peak torque did not differ between diet groups. These data suggest that vegetarian diets do not compromise performance outcomes and may facilitate aerobic capacity in athletes.

  19. Prevalence of Subclinical Coronary Artery Disease in Masters Endurance Athletes With a Low Atherosclerotic Risk Profile.

    Science.gov (United States)

    Merghani, Ahmed; Maestrini, Viviana; Rosmini, Stefania; Cox, Andrew T; Dhutia, Harshil; Bastiaenan, Rachel; David, Sarojini; Yeo, Tee Joo; Narain, Rajay; Malhotra, Aneil; Papadakis, Michael; Wilson, Mathew G; Tome, Maite; AlFakih, Khaled; Moon, James C; Sharma, Sanjay

    2017-07-11

    Studies in middle-age and older (masters) athletes with atherosclerotic risk factors for coronary artery disease report higher coronary artery calcium (CAC) scores compared with sedentary individuals. Few studies have assessed the prevalence of coronary artery disease in masters athletes with a low atherosclerotic risk profile. We assessed 152 masters athletes 54.4±8.5 years of age (70% male) and 92 controls of similar age, sex, and low Framingham 10-year coronary artery disease risk scores with an echocardiogram, exercise stress test, computerized tomographic coronary angiogram, and cardiovascular magnetic resonance imaging with late gadolinium enhancement and a 24-hour Holter. Athletes had participated in endurance exercise for an average of 31±12.6 years. The majority (77%) were runners, with a median of 13 marathon runs per athlete. Most athletes (60%) and controls (63%) had a normal CAC score. Male athletes had a higher prevalence of atherosclerotic plaques of any luminal irregularity (44.3% versus 22.2%; P =0.009) compared with sedentary males, and only male athletes showed a CAC ≥300 Agatston units (11.3%) and a luminal stenosis ≥50% (7.5%). Male athletes demonstrated predominantly calcific plaques (72.7%), whereas sedentary males showed predominantly mixed morphology plaques (61.5%). The number of years of training was the only independent variable associated with increased risk of CAC >70th percentile for age or luminal stenosis ≥50% in male athletes (odds ratio, 1.08; 95% confidence interval, 1.01-1.15; P =0.016); 15 (14%) male athletes but none of the controls revealed late gadolinium enhancement on cardiovascular magnetic resonance imaging. Of these athletes, 7 had a pattern consistent with previous myocardial infarction, including 3(42%) with a luminal stenosis ≥50% in the corresponding artery. Most lifelong masters endurance athletes with a low atherosclerotic risk profile have normal CAC scores. Male athletes are more likely to have a CAC