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Sample records for junior solar sprint

  1. Junior Solar Sprint.

    Science.gov (United States)

    O'Shea, Aisling

    1997-01-01

    Reports on a project sponsored by the United States Department of Energy (DOE) that engages students in building solar cars in groups with kits that include a three volt panel. The design and engineering decisions are made by the students using pertinent information. (DDR)

  2. Solar Sprint

    Science.gov (United States)

    Tabor, Richard; Anderson, Stephen

    2007-01-01

    In the "Solar Sprint" activity, students design, test, and race a solar-powered car built with Legos. The use of ratios is incorporated to simulate the actual work of scientists and engineers. This method encourages fourth-grade students to think about multiple variables and stimulates their curiosity when an activity doesn't come out as…

  3. The post-activation potentiation effect on sprint performance after combined resistance/sprint training in junior basketball players.

    Science.gov (United States)

    Tsimachidis, Constantinos; Patikas, Dimitrios; Galazoulas, Christos; Bassa, Eleni; Kotzamanidis, Christos

    2013-01-01

    The aim of this study was to examine the effect of a 10-week combined resistance/sprint training programme in the post-activation potentiation of sprint performance before, between and after resistance training sets. Twenty-six junior basketball players were randomly divided into a control and a combined training group. The combined training group performed a combined training programme consisting of 5 sets at 5-8 RM (Repetition Maximum) half-squats with sprints performed between each set. Post-activation potentiation was considered as the increase in sprint velocity in trials executed between and after the resistance sets compared with the sprint trial performed before the resistance sets of the respective first and last training session. For sprint evaluation the running distances 0-10 and 0-30 m were selected. The intervention increased both strength and sprint performance. No post-activation potentiation effect was observed during the first training session in either group. Post-activation potentiation appeared in the combined training group during the last training session of the intervention in both 0-10 and 0-30 m sprint. This study illustrates that post-activation potentiation effect on sprint performance in junior basketball players, who did not previously follow systematic resistance training, emerges after a 10-week resistance/sprint combined training programme.

  4. Effects of an In-season Plyometric Training Program on Repeated Change of Direction and Sprint Performance in the Junior Soccer Player.

    Science.gov (United States)

    Hammami, Mehréz; Negra, Yassine; Aouadi, Ridha; Shephard, Roy J; Chelly, Mohamed Souhaiel

    2016-12-01

    Hammami, M, Negra, Y, Aouadi, R, Shephard, RJ, and Chelly, MS. Effects of an in-season plyometric training program on repeated change of direction and sprint performance in the junior soccer player. J Strength Cond Res 30(12): 3312-3320, 2016-We aimed to determine the gains in explosive movements of male junior soccer players induced by incorporating an 8-week plyometric training program (PTP) into a standard soccer conditioning regimen 5 months after the beginning of the competitive season. Our hypothesis was that PTP would enhance explosive movements, and thus sprint running, repeated shuttle sprint ability (RSSA), agility and the ability to make repeated changes of direction (RCOD). A group of junior soccer players were randomly divided into 2 groups: an experimental group (E, n = 15, age 15.7 ± 0.2 years) and a control group (C, n = 13, age 15.8 ± 0.2 years). The participants in E and C performed training exercises and matches together, but for an 8-week period in the latter part of the season, the experimental group replaced a part of the normal regimen (the tactical session) by a biweekly course of PTP (hurdle and drop jumps). Two familiarization sessions were held 2 weeks before definitive testing. The ability of the players was assessed by 3 agility tests (a sprint test with 180° turns, a 9-3-6-3-9 m sprint with backward and forward running, and a four 5-m sprint test with turns); 2 repeated sprint tests (RSSA and RCOD); and running times over 5-, 10-, 20-, 30-, and 40-m distances. Participants in E showed gains relative to C in sprint times (p ≤ 0.05 for 5, 10, and 20 m), and 2 of 3 the RCOD parameters (RCOD best, p ≤ 0.001; RCOD total, p ≤ 0.05). However, with the pattern of plyometric training that we adopted, and perhaps because participants were in good initial physical condition, the agility and RSSA test scores remained unchanged. Nevertheless, we conclude that our PTP can be commended to junior soccer players as a means of improving

  5. Comparison of ergometer- and track-based testing in junior track-sprint cyclists. Implications for talent identification and development.

    Science.gov (United States)

    Tofari, Paul J; Cormack, Stuart J; Ebert, Tammie R; Gardner, A Scott; Kemp, Justin G

    2017-10-01

    Talent identification (TID) and talent development (TDE) programmes in track sprint cycling use ergometer- and track-based tests to select junior athletes and assess their development. The purpose of this study was to assess which tests are best at monitoring TID and TDE. Ten male participants (16.2 ± 1.1 year; 178.5 ± 6.0 cm and 73.6 ± 7.6 kg) were selected into the national TID squad based on initial testing. These tests consisted of two 6-s maximal sprints on a custom-built ergometer and 4 maximal track-based tests (2 rolling and 2 standing starts) using 2 gear ratios. Magnitude-based inferences and correlation coefficients assessed changes following a 3-month TDE programme. Training elicited meaningful improvements (80-100% likely) in all ergometer parameters. The standing and rolling small gear, track-based effort times were likely and very likely (3.2 ± 2.4% and 3.3 ± 1.9%, respectively) improved by training. Stronger correlations between ergometer- and track-based measures were very likely following training. Ergometer-based testing provides a more sensitive tool than track-based testing to monitor changes in neuromuscular function during the early stages of TDE. However, track-based testing can indicate skill-based improvements in performance when interpreted with ergometer testing. In combination, these tests provide information on overall talent development.

  6. Multi Directional Repeated Sprint Is a Valid and Reliable Test for Assessment of Junior Handball Players

    Directory of Open Access Journals (Sweden)

    Amin Daneshfar

    2018-04-01

    Full Text Available The aim of the present study was to examine the validity and reliability of a 10 × (6 × 5 m multi-directional repeated sprint ability test (RSM in elite young team handball (TH players. Participants were members of the Iranian national team (n = 20, age 16.4 ± 0.7 years, weight 82.5 ± 5.5 kg, height 184.8 ± 4.6 cm, body fat 15.4 ± 4.3%. The validity of RSM was tested against a 10 × (15 + 15 m repeated sprint ability test (RSA, Yo-Yo Intermittent Recovery test Level 1 (Yo-Yo IR1, squat jump (SJ and countermovement jump (CMJ. To test the reliability of RSM, the participants repeated the testing sessions of RSM and RSA 1 week later. Both RSA and RSM tests showed good to excellent reliability of the total time (TT, best time (BT, and weakest time (WT. The results of the correlation analysis showed significant inverse correlations between maximum aerobic capacity and TT in RSA (r = −0.57, p ≤ 0.05 and RSM (r = −0.76, p ≤ 0.01. There was also a significant inverse correlation between maximum aerobic capacity with fatigue index (FI in RSA test (r = −0.64, p ≤ 0.01 and in RSM test (r = −0.53, p ≤ 0.05. BT, WT, and TT of RSA was largely-to-very largely correlated with BT (r = 0.58, p ≤ 0.01, WT (r = 0.62, p ≤ 0.01, and TT (r = 0.65, p ≤ 0.01 of RSM. BT in RSM was also correlated with FI in RSM (r = 0.88, p ≤ 0.01. In conclusion, based on the findings of the current study, the recently developed RSM test is a valid and reliable test and should be utilized for assessment of repeated sprint ability in handball players.

  7. Multi Directional Repeated Sprint Is a Valid and Reliable Test for Assessment of Junior Handball Players

    Science.gov (United States)

    Daneshfar, Amin; Gahreman, Daniel E.; Koozehchian, Majid S.; Amani Shalamzari, Sadegh; Hassanzadeh Sablouei, Mozhgan; Rosemann, Thomas; Knechtle, Beat; Nikolaidis, Pantelis T.

    2018-01-01

    The aim of the present study was to examine the validity and reliability of a 10 × (6 × 5 m) multi-directional repeated sprint ability test (RSM) in elite young team handball (TH) players. Participants were members of the Iranian national team (n = 20, age 16.4 ± 0.7 years, weight 82.5 ± 5.5 kg, height 184.8 ± 4.6 cm, body fat 15.4 ± 4.3%). The validity of RSM was tested against a 10 × (15 + 15 m) repeated sprint ability test (RSA), Yo-Yo Intermittent Recovery test Level 1 (Yo-Yo IR1), squat jump (SJ) and countermovement jump (CMJ). To test the reliability of RSM, the participants repeated the testing sessions of RSM and RSA 1 week later. Both RSA and RSM tests showed good to excellent reliability of the total time (TT), best time (BT), and weakest time (WT). The results of the correlation analysis showed significant inverse correlations between maximum aerobic capacity and TT in RSA (r = −0.57, p ≤ 0.05) and RSM (r = −0.76, p ≤ 0.01). There was also a significant inverse correlation between maximum aerobic capacity with fatigue index (FI) in RSA test (r = −0.64, p ≤ 0.01) and in RSM test (r = −0.53, p ≤ 0.05). BT, WT, and TT of RSA was largely-to-very largely correlated with BT (r = 0.58, p ≤ 0.01), WT (r = 0.62, p ≤ 0.01), and TT (r = 0.65, p ≤ 0.01) of RSM. BT in RSM was also correlated with FI in RSM (r = 0.88, p ≤ 0.01). In conclusion, based on the findings of the current study, the recently developed RSM test is a valid and reliable test and should be utilized for assessment of repeated sprint ability in handball players. PMID:29670536

  8. Effects of small-sided games and high-intensity interval training on aerobic and repeated sprint performance and peripheral muscle oxygenation changes in elite junior basketball players.

    Science.gov (United States)

    Delextrat, A; Gruet, M; Bieuzen, F

    2018-03-06

    The aim of the current study was to compare the effects of 6 weeks of small-sided game (SSG) and high-intensity interval training (HIIT) on aerobic fitness and muscle oxygenation during a repeated sprint (RS) sequence in elite male junior basketball players. Twenty participants (14.3 ± 0.5 years; 176.8 ± 12.5 cm; 74.5 ± 9.8 kg) performed pre- and post-tests interspersed by 6-weeks of SSG or HIIT training. Testing sessions consisted of the 30-15 Intermittent Fitness Test and a RS sequence (two bouts of 15-s). During RS, muscle oxygenation parameters (tissue saturation index (TSI, %), post-sprint muscle reoxygenation rate) were measured by near-infrared spectroscopy (NIRS). The results showed that both training interventions similarly improved maximal aerobic speed (VIFT, 3.4 and 4.1%, respectively for HIIT and SSG, Ptraining interventions also resulted in a greater ΔTSI during the second sprint (47.8% to 114%, Ptrainings are applicable methodologies to improve in-season aerobic and anaerobic fitness capacities in junior basketball players.

  9. Isolated core training improves sprint performance in national-level junior swimmers.

    Science.gov (United States)

    Weston, Matthew; Hibbs, Angela E; Thompson, Kevin G; Spears, Iain R

    2015-03-01

    To quantify the effects of a 12-wk isolated core-training program on 50-m front-crawl swim time and measures of core musculature functionally relevant to swimming. Twenty national-level junior swimmers (10 male and 10 female, 16±1 y, 171±5 cm, 63±4 kg) participated in the study. Group allocation (intervention [n=10], control [n=10]) was based on 2 preexisting swim-training groups who were part of the same swimming club but trained in different groups. The intervention group completed the core training, incorporating exercises targeting the lumbopelvic complex and upper region extending to the scapula, 3 times/wk for 12 wk. While the training was performed in addition to the normal pool-based swimming program, the control group maintained their usual pool-based swimming program. The authors made probabilistic magnitude-based inferences about the effect of the core training on 50-m swim time and functionally relevant measures of core function. Compared with the control group, the core-training intervention group had a possibly large beneficial effect on 50-m swim time (-2.0%; 90% confidence interval -3.8 to -0.2%). Moreover, it showed small to moderate improvements on a timed prone-bridge test (9.0%; 2.1-16.4%) and asymmetric straight-arm pull-down test (23.1%; 13.7-33.4%), and there were moderate to large increases in peak EMG activity of core musculature during isolated tests of maximal voluntary contraction. This is the first study to demonstrate a clear beneficial effect of isolated core training on 50-m front-crawl swim performance.

  10. Solar Energy Education. Renewable energy activities for junior high/middle school science

    Energy Technology Data Exchange (ETDEWEB)

    1985-01-01

    Some basic topics on the subject of solar energy are outlined in the form of a teaching manual. The manual is geared toward junior high or middle school science students. Topics include solar collectors, solar water heating, solar radiation, insulation, heat storage, and desalination. Instructions for the construction of apparatus to demonstrate the solar energy topics are provided. (BCS)

  11. Junior Solar Sprint: Securing Students’ Enthusiasm for Science and Engineering

    Science.gov (United States)

    2010-09-24

    Department of Energy; Toyota Foundation; US Army C. JSS Program An exciting, top notch Northeast Championship rests on the foundation of a high quality...for volunteers 5. Roles for children 6. Volunteer advertisement C. Stipend Positions 1. Photographers 2. Interns 3. Special projects (e.g... ADVERTISEMENT • ONYX Restaurant - Western New England’s awarding Winning Restaurant & Bar! • Register Now for Fall Classes! • Noble Hospital - Click

  12. Students To Compete in Model Solar Car Race

    Science.gov (United States)

    cars in the 1998 Junior Solar Sprint. The race will be held at the U.S. Department of Energy's (DOE Compete in Model Solar Car Race For more information contact: e:mail: Public Affairs Golden, Colo ., May 8, 1998 — Middle school students from across Colorado will design, build and race model solar

  13. Aoyama Gakuin University team winning the second prize in junior class in a solar car race; Aogaku team wa junior nii (solar car race ni sankashite)

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, Y. [Aoyama Gakuin University, Tokyo (Japan)

    1994-09-20

    This paper introduces how the Aoyama Gakuin University team competed in the World Solar Car Rally race held at Ogata Village in Akita Prefecture, Japan, in the summer of 1994. The race was formed with solar cars mounting a solar panel with the maximum area of 8 m{sup 2} and batteries with a total output of 3 kWh to compete how many rounds the cars can run around a course of 31 km during three days (25 hours in total). The solar car used by the University team had consumed power of about 600 W at a speed of 40 km/h, with the solar panel generating power of 800 Wp. The first day morning was sunny making possible to set the average speed to 45 km/h (power generation of 500 W or more), but the weather worsened in the afternoon compelling the car to change the speed to 30 km/h (power generation of 200 W). The power generated on the second day, which was cloudy all day, stayed at 250 W at the maximum, hence the speed was kept at 30 km/h to suppress the power consumption. On the sunny third day, the team drove the car worrying about the remaining battery capacity, and succeeded the drive of 23 rounds in total, winning the second prize among 30 cars participated in the junior class race.

  14. Bases of technique of sprinting

    Directory of Open Access Journals (Sweden)

    Valeriy Druz

    2015-06-01

    Full Text Available Purpose: to determine the biomechanical consistent patterns of a movement of a body providing the highest speed of sprinting. Material and Methods: the analysis of scientific and methodical literature on the considered problem, the anthropometrical characteristics of the surveyed contingent of sportsmen, the analysis of high-speed shootings of the leading runners of the world. Results: the biomechanical bases of technique of sprinting make dispersal and movement of the general center of body weight of the sportsman on a parabolic curve in a start phase taking into account the initial height of its stay in a pose of a low start. Its further movement happens on a cycloidal trajectory which is formed due to a pendulum movement of the extremities creating the lifting power which provides flight duration more in a running step, than duration of a basic phase. Conclusions: the received biomechanical regularities of technique of sprinting allow increasing the efficiency of training of sportsmen in sprinting.

  15. High performance image processing of SPRINT

    Energy Technology Data Exchange (ETDEWEB)

    DeGroot, T. [Lawrence Livermore National Lab., CA (United States)

    1994-11-15

    This talk will describe computed tomography (CT) reconstruction using filtered back-projection on SPRINT parallel computers. CT is a computationally intensive task, typically requiring several minutes to reconstruct a 512x512 image. SPRINT and other parallel computers can be applied to CT reconstruction to reduce computation time from minutes to seconds. SPRINT is a family of massively parallel computers developed at LLNL. SPRINT-2.5 is a 128-node multiprocessor whose performance can exceed twice that of a Cray-Y/MP. SPRINT-3 will be 10 times faster. Described will be the parallel algorithms for filtered back-projection and their execution on SPRINT parallel computers.

  16. Expo Junior

    CERN Document Server

    Staff Association

    2014-01-01

    Fort de son succès Expo Juniors revient du 22 au 23 novembre 2014 - Papa & Maman Noël seront présents ! Nous avons le plaisir de  proposer à nos membres des billets d'entrées  à un tarif préférentiel, au prix de CHF 10.- l'unité au lieu de CHF 18.- (gratuit pour les enfants de 0 à 4 ans). Des centaines d’ateliers répartis en 3 villages : Sports & Loisirs, Jeux & Jouets, Éducation & Vie pratique. Cet événement propose aux familles aussi d'autres thèmes : tourisme, idées cadeaux, mode, bien-être, beauté, décoration, ainsi que des services destinés aux familles. Parades, attractions, castings, défilés de mode, dédicaces, séances photos avec Papa Noël, ainsi que de nombre...

  17. Simulation of aperiodic bipedal sprinting.

    Science.gov (United States)

    Celik, Huseyin; Piazza, Stephen J

    2013-08-01

    Synthesis of legged locomotion through dynamic simulation is useful for exploration of the mechanical and control variables that contribute to efficient gait. Most previous simulations have made use of periodicity constraints, a sensible choice for investigations of steady-state walking or running. Sprinting from rest, however, is aperiodic by nature and this aperiodicity is central to the goal of the movement, as performance is determined in large part by a rapid acceleration phase early in the race. The purpose of this study was to create a novel simulation of aperiodic sprinting using a modified spring-loaded inverted pendulum (SLIP) biped model. The optimal control problem was to find the set of controls that minimized the time for the model to run 20 m, and this problem was solved using a direct multiple shooting algorithm that converts the original continuous time problem into piecewise discrete subproblems. The resulting nonlinear programming problem was solved iteratively using a sequential quadratic programming method. The starting point for the optimizer was an initial guess simulation that was a slow alternating-gait "jogging" simulation developed using proportional-derivative feedback to control trunk attitude, swing leg angle, and leg retraction and extension. The optimized aperiodic sprint simulation solution yielded a substantial improvement in locomotion time over the initial guess (2.79 s versus 6.64 s). Following optimization, the model produced forward impulses at the start of the sprint that were four times greater than those of the initial guess simulation, producing more rapid acceleration. Several gait features demonstrated in the optimized sprint simulation correspond to behaviors of human sprinters: forward trunk lean at the start; straightening of the trunk during acceleration; and a dive at the finish. Optimization resulted in reduced foot contact times (0.065 s versus 0.210 s), but contact times early in the optimized

  18. Push Characteristics in Wheelchair Court Sport Sprinting

    NARCIS (Netherlands)

    van der Slikke, Rienk M A; Berger, Monique; Bregman, Daan; Veeger, Dirkjan

    2016-01-01

    Short sprints are important components of most wheelchair court sports, since being faster than the opponent often determines keeping ball possession or not. Sprinting capacity is best measured during a field test, allowing the athlete to freely choose push strategies adapted to their own wheelchair

  19. Push characteristics in wheelchair court sport sprinting

    NARCIS (Netherlands)

    van der Slikke, R.M.A.; Berger, Monique; Bregman, D.J.J.; Veeger, H.E.J.; van der Helm, FCT; Jansen, AJ

    2016-01-01

    Short sprints are important components of most wheelchair court sports, since being faster than the opponent often determines keeping ball possession or not. Sprinting capacity is best measured during a field test, allowing the athlete to freely choose push strategies adapted to their own

  20. Effects of supplementation with acai (Euterpe oleracea Mart.) berry-based juice blend on the blood antioxidant defence capacity and lipid profile in junior hurdlers. A pilot study

    OpenAIRE

    Sadowska-Kr?pa, E; K?apci?ska, B; Podg?rski, T; Szade, B; Tyl, K; Hadzik, A

    2015-01-01

    The purpose of this pilot study was to examine whether regular consumption of an acai berry-based juice blend would affect sprint performance and improve blood antioxidant status and lipid profile in junior athletes. Seven junior hurdlers (17.5±1.2 years) taking part in a pre-season conditioning camp were supplemented once a day, for six weeks, with 100 ml of the juice blend. At the start and the end of the camp the athletes performed a 300-m sprint running test on an outdoor track. Blood sam...

  1. Muscle activity in sprinting: a review.

    Science.gov (United States)

    Howard, Róisín M; Conway, Richard; Harrison, Andrew J

    2018-03-01

    The use of electromyography (EMG) is widely recognised as a valuable tool for enhancing the understanding of performance drivers and potential injury risk in sprinting. The timings of muscle activations relative to running gait cycle phases and the technology used to obtain muscle activation data during sprinting are of particular interest to scientists and coaches. This review examined the main muscles being analysed by surface EMG (sEMG), their activations and timing, and the technologies used to gather sEMG during sprinting. Electronic databases were searched using 'Electromyography' OR 'EMG' AND 'running' OR 'sprinting'. Based on inclusion criteria, 18 articles were selected for review. While sEMG is widely used in biomechanics, relatively few studies have used sEMG in sprinting due to system constraints. The results demonstrated a focus on the leg muscles, with over 70% of the muscles analysed in the upper leg. This is consistent with the use of tethered and data logging EMG systems and many sprints being performed on treadmills. Through the recent advances in wireless EMG technology, an increase in the studies on high velocity movements such as sprinting is expected and this should allow practitioners to perform the analysis in an ecologically valid environment.

  2. Space Radiation Intelligence System (SPRINTS), Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — NextGen Federal Systems proposes an innovative SPace Radiation INTelligence System (SPRINTS) which provides an interactive and web-delivered capability that...

  3. Sled Towing Acutely Decreases Acceleration Sprint Time.

    Science.gov (United States)

    Wong, Megan A; Dobbs, Ian J; Watkins, Casey M; Barillas, Saldiam R; Lin, Anne; Archer, David C; Lockie, Robert G; Coburn, Jared W; Brown, Lee E

    2017-11-01

    Wong, MA, Dobbs, IJ, Watkins, C, Barillas, SR, Lin, A, Archer, DC, Lockie, RG, Coburn, JW, and Brown, LE. Sled towing acutely decreases acceleration sprint time. J Strength Cond Res 31(11): 3046-3051, 2017-Sled towing is a common form of overload training in sports to develop muscular strength for sprinting. This type of training leads to acute and chronic outcomes. Acute training potentially leads to postactivation potentiation (PAP), which is when subsequent muscle performance is enhanced after a preload stimulus. The purpose of this study was to determine differences between rest intervals after sled towing on acute sprint speed. Twenty healthy recreationally trained men (age = 22.3 ± 2.4 years, height = 176.95 ± 5.46 cm, mass = 83.19 ± 11.31 kg) who were currently active in a field sport twice a week for the last 6 months volunteered to participate. A maximal 30-meter (m) baseline (BL) body mass (BM) sprint was performed (with splits at 5, 10, 20, and 30 m) followed by 5 visits where participants sprinted 30 m towing a sled at 30% BM then rested for 2, 4, 6, 8, or 12 minutes. They were instructed to stand still during rest times. After the rest interval, they performed a maximal 30-m post-test BM sprint. Analysis of variance (ANOVA) revealed that post sled tow BM sprint times (4.47 ± 0.21 seconds) were less than BL times (4.55 ± 0.18 seconds) on an individualized rest interval basis. A follow-up 2 × 4 ANOVA showed that this decrease occurred only in the acceleration phase over the first 5 m (BL = 1.13 ± 0.08 seconds vs. Best = 1.08 ± 0.08 seconds), which may be the result of PAP and the complex relationship between fatigue and potentiation relative to the intensity of the sled tow and the rest interval. Therefore, coaches should test their athletes on an individual basis to determine optimal rest time after a 30-m 30% BM sled tow to enhance acute sprint speed.

  4. Profiling of Junior College Football Players and Differences between Position Groups

    Directory of Open Access Journals (Sweden)

    Robert G. Lockie

    2016-08-01

    Full Text Available This study profiled junior college football players. Sixty-two subjects completed vertical jump (VJ; height and peak power, standing broad jump (SBJ, 36.58 m sprint, pro-agility shuttle, three-cone drill, and maximal-repetition bench press and front squat. The sample included 2 quarterbacks (QB, 7 running backs (RB, 13 wide receivers (WR, 1 tight end (TE, 18 defensive backs (DB, 8 linebackers (LB, and 13 offensive and defensive linemen (LM. To investigate positional differences, subjects were split into skill (SK; WR, DB, big skill (BSK; QB, RB, TE, LB, and LM groups. A one-way ANOVA determined between-group differences. LM were taller and heavier than SK and BSK players. The SK and BSK groups were faster than LM in the 0–36.58 m sprint, pro-agility shuttle, and three-cone drill (p ≤ 0.009. The SK group had greater VJ height and SBJ distance; LM generated greater VJ peak power (p ≤ 0.022. There were no between-group differences in the strength endurance tests. Compared to Division I data, junior college players were smaller, slower, and performed worse in jump tests. Positional differences in junior college football are typical to that of established research. Junior college players should attempt to increase body mass, and improve speed and lower-body power.

  5. Collecting Solar Energy. Solar Energy Education Project.

    Science.gov (United States)

    O'Brien, Alexander

    This solar energy learning module for use with junior high school students offers a list of activities, a pre-post test, job titles, basic solar energy vocabulary, and diagrams of solar energy collectors and installations. The purpose is to familiarize students with applications of solar energy and titles of jobs where this knowledge could be…

  6. Online video-based resistance training improves the physical capacity of junior basketball athletes.

    Science.gov (United States)

    Klusemann, Markus J; Pyne, David B; Fay, Tristan S; Drinkwater, Eric J

    2012-10-01

    Junior basketball athletes require a well-designed resistance training program to improve their physical development. Lack of expert supervision and resistance training in junior development pathways may be overcome by implementing an online video-based program. The aim of this study was to compare the magnitude of improvement (change) in physical performance and strength and functional movement patterns of junior basketball athletes using either a fully supervised or an online video-based resistance training program. Thirty-eight junior basketball athletes (males, n = 17; age, 14 ± 1 year; height, 1.79 ± 0.10 m; mass, 67 ± 12 kg; females, n = 21; age, 15 ± 1 year; height, 1.70 ± 0.07 m; mass, 62 ± 8 kg) were randomly assigned into a supervised resistance training group (SG, n = 13), video training group (VG, n = 13) or control group (CG, n = 12) and participated in a 6-week controlled experimental trial. Pre- and posttesting included measures of physical performance (20-m sprint, step-in vertical jump, agility, sit and reach, line drill, and Yo-Yo intermittent recovery level 1), strength (15 s push-up and pull-up), and functional movement screening (FMS). Both SG and VG achieved 3-5% ± 2-4% (mean ± 90% confidence limits) greater improvements in several physical performance measures (vertical jump height, 20-m sprint time, and Yo-Yo endurance performance) and a 28 ± 21% greater improvement in push-up strength compared with the CG. The SG attained substantially larger gains in FMS scores over both the VG (12 ± 10%) and CG (13 ± 8%). Video-based training appears to be a viable option to improve physical performance and strength in junior basketball athletes. Qualified supervision is recommended to improve functional movement patterns in junior athletes.

  7. NREL Model Car Competitions | NREL

    Science.gov (United States)

    work together building cars with guidance from a parent, teacher, or coach to compete in race and Solar and Lithium Ion model car races in Colorado. Building solar- and battery-powered cars requires listPDF for Junior Solar Sprint and Lithium-Ion Battery model cars. Junior Solar Sprint Solar Made Pitsco

  8. Attentional and visual demands for sprint performance in non-fatigued and fatigued conditions: reliability of a repeated sprint test

    Directory of Open Access Journals (Sweden)

    Diercks Ron L

    2010-05-01

    Full Text Available Abstract Background Physical performance measures are widely used to assess physical function, providing information about physiological and biomechanical aspects of motor performance. However they do not provide insight into the attentional and visual demands for motor performance. A figure-of-eight sprint test was therefore developed to measure the attentional and visual demands for repeated-sprint performance. The aims of the study were: 1 to assess test-retest reliability of the figure-of-eight sprint test, and 2 to study the attentional and visual demands for sprint performance in a non-fatigued and fatigued condition. Methods Twenty-seven healthy athletes were included in the study. To determine test-retest reliability, a subgroup of 19 athletes performed the figure-of-eight sprint test twice. The figure-of-eight sprint test consisted of nine 30-second sprints. The sprint test consisted of three test parts: sprinting without any restriction, with an attention-demanding task, and with restricted vision. Increases in sprint times with the attention-demanding task or restricted vision are reflective of the attentional and visual demands for sprinting. Intraclass correlation coefficients (ICCs and mean difference between test and retest with 95% confidence limits (CL were used to assess test-retest reliability. Repeated-measures ANOVA were used for comparisons between the sprint times and fatigue measurements of the test parts in both a non-fatigued and fatigued condition. Results The figure-of-eight sprint test showed good test-retest reliability, with ICCs ranging from 0.75 to 0.94 (95% CL: 0.40-0.98. Zero lay within the 95% CL of the mean differences, indicating that no bias existed between sprint performance at test and retest. Sprint times during the test parts with attention-demanding task (P = 0.01 and restricted vision (P Conclusions High ICCs and the absence of systematic variation indicate good test-retest reliability of the figure

  9. Energetic Profile of the Basketball Exercise Simulation Test in Junior Elite Players.

    Science.gov (United States)

    Latzel, Richard; Hoos, Olaf; Stier, Sebastian; Kaufmann, Sebastian; Fresz, Volker; Reim, Dominik; Beneke, Ralph

    2017-11-28

    To analyze the energetic profile of the basketball exercise simulation test (BEST). 10 male elite junior basketball players (age: 15.5±0.6yrs, height: 180±9cm, body mass: 66.1±11.2kg) performed a modified BEST (20 circuits consisting of jumping, sprinting, jogging, shuffling, and short breaks) simulating professional basketball game play. Circuit time, sprint time, sprint decrement, oxygen uptake (VO2), heart rate (HR), and blood lactate concentration (BLC) were obtained. Metabolic energy and metabolic power above rest (W tot , P tot ) as well as energy share in terms of aerobic (W aer ), glycolytic (W blc ), and high energy phosphates (W PCr ) were calculated from VO2 during exercise, net lactate production, and the fast component of post-exercise VO2 kinetics, respectively. W aer , W blc , and W PCr reflect 89±2%, 5±1%, and 6±1% of total energy needed, respectively. Assuming an aerobic replenishment of PCr energy stores during short breaks, the adjusted energy share yielded W aer : 66±4%, W blc : 5±1%, and W PCr : 29±1%. W aer and W PCr were negatively correlated (-0.72, -0.59) with sprint time, which was not the case for W blc . Consistent with general findings on energy system interaction during repeated high intensity exercise bouts, the intermittent profile of the BEST relies primarily on aerobic energy combined with repetitive supplementation by anaerobic utilization of high energy phosphates.

  10. SPRINT: A new parallel framework for R

    Directory of Open Access Journals (Sweden)

    Scharinger Florian

    2008-12-01

    Full Text Available Abstract Background Microarray analysis allows the simultaneous measurement of thousands to millions of genes or sequences across tens to thousands of different samples. The analysis of the resulting data tests the limits of existing bioinformatics computing infrastructure. A solution to this issue is to use High Performance Computing (HPC systems, which contain many processors and more memory than desktop computer systems. Many biostatisticians use R to process the data gleaned from microarray analysis and there is even a dedicated group of packages, Bioconductor, for this purpose. However, to exploit HPC systems, R must be able to utilise the multiple processors available on these systems. There are existing modules that enable R to use multiple processors, but these are either difficult to use for the HPC novice or cannot be used to solve certain classes of problems. A method of exploiting HPC systems, using R, but without recourse to mastering parallel programming paradigms is therefore necessary to analyse genomic data to its fullest. Results We have designed and built a prototype framework that allows the addition of parallelised functions to R to enable the easy exploitation of HPC systems. The Simple Parallel R INTerface (SPRINT is a wrapper around such parallelised functions. Their use requires very little modification to existing sequential R scripts and no expertise in parallel computing. As an example we created a function that carries out the computation of a pairwise calculated correlation matrix. This performs well with SPRINT. When executed using SPRINT on an HPC resource of eight processors this computation reduces by more than three times the time R takes to complete it on one processor. Conclusion SPRINT allows the biostatistician to concentrate on the research problems rather than the computation, while still allowing exploitation of HPC systems. It is easy to use and with further development will become more useful as more

  11. The relationship between ventilatory threshold and repeated-sprint ability in competitive male ice hockey players

    Directory of Open Access Journals (Sweden)

    Matthew R. Lowery

    2018-04-01

    Full Text Available Background/objective: The relationship between ventilatory threshold (VT1, VT2 and repeated-sprint ability (RSA in competitive male ice hockey players was investigated. Methods: Forty-three male ice hockey players aged 18–23 years competing in NCAA Division I, NCAA Division III, and Junior A level participated. Participants performed an incremental graded exercise test on a skate treadmill to determine V˙O2peak, VT1, and VT2 using MedGraphics Breezesuit™ software (v-slope. Participants performed an on-ice repeated shift (RSA test consisting of 8-maximal skating bouts, lasting approximately 25 s and interspersed with 90 s of passive recovery, to determine first gate, second gate, and total sprint decrement (%dec. Pearson product-moment correlations and multiple regressions were used to assess relationships between ventilatory threshold variables (VT1, VT2, Stage at VT1, and Stage at VT2 and RSA (first gate, second gate, and total course decrement. Results: Stage at VT2 was the only variable substantially correlated with first gate (r = −0.35; P < 0.05, second gate (r = −0.58; P < 0.001 and total course decrement (r = −0.42; P < 0.05. Conclusion: The results of this study demonstrated that VT is substantially associated with RSA, and VT2 is more strongly correlated with RSA than V˙O2peak. This study suggests that longer duration high-intensity interval training at intensities that increase workrate at VT2 may lead to possible improvements in RSA. Keywords: Athletes, Aerobic capacity, Fatigue, Sprint decrement

  12. Comparison of physical activities of female football players in junior high school and high school.

    Science.gov (United States)

    Inoue, Yuri; Otani, Yoshitaka; Takemasa, Seiichi

    2017-08-01

    [Purpose] This study aimed to compare physical activities between junior high school and high school female football players in order to explain the factors that predispose to a higher incidence of sports injuries in high school female football players. [Subjects and Methods] Twenty-nine female football players participated. Finger floor distance, the center of pressure during single limb stance with eyes open and closed, the 40-m linear sprint time, hip abduction and extension muscle strength and isokinetic knee flexion and extension peak torque were measured. The modified Star Excursion Balance Test, the three-steps bounding test and three-steps hopping tests, agility test 1 (Step 50), agility test 2 (Forward run), curl-up test for 30 seconds and the Yo-Yo intermittent recovery test were performed. [Results] The high school group was only significantly faster than the junior high school group in the 40-m linear sprint time and in the agility tests. The distance of the bounding test in the high school group was longer than that in the junior high school group. [Conclusion] Agility and speed increase with growth; however, muscle strength and balance do not develop alongside. This unbalanced development may cause a higher incidence of sports injuries in high school football players.

  13. Comparison of physical capacities between nonselected and selected elite male competitive surfers for the National Junior Team.

    Science.gov (United States)

    Tran, Tai T; Lundgren, Lina; Secomb, Josh; Farley, Oliver R L; Haff, G Gregory; Seitz, Laurent B; Newton, Robert U; Nimphius, Sophia; Sheppard, Jeremy M

    2015-03-01

    To determine whether a previously validated performance-testing protocol for competitive surfers is able to differentiate between Australian elite junior surfers selected (S) to the national team and those not selected (NS). Thirty-two elite male competitive junior surfers were divided into 2 groups (S=16, NS=16). Their age, height, body mass, sum of 7 skinfolds, and lean-body-mass ratio (mean±SD) were 16.17±1.26 y, 173.40±5.30 cm, 62.35±7.40 kg, 41.74±10.82 mm, 1.54±0.35 for the S athletes and 16.13±1.02 y, 170.56±6.6 cm, 61.46±10.10 kg, 49.25±13.04 mm, 1.31±0.30 for the NS athletes. Power (countermovement jump [CMJ]), strength (isometric midthigh pull), 15-m sprint paddling, and 400-m endurance paddling were measured. There were significant (P≤.05) differences between the S and NS athletes for relative vertical-jump peak force (P=.01, d=0.9); CMJ height (P=.01, d=0.9); time to 5-, 10-, and 15-m sprint paddle; sprint paddle peak velocity (P=.03, d=0.8; PV); time to 400 m (P=.04, d=0.7); and endurance paddling velocity (P=.05, d=0.7). All performance variables, particularly CMJ height; time to 5-, 10-, and 15-m sprint paddle; sprint paddle PV; time to 400 m; and endurance paddling velocity, can effectively discriminate between S and NS competitive surfers, and this may be important for athlete profiling and training-program design.

  14. Development of Repeated Sprint Ability in Talented Youth Basketball Players

    NARCIS (Netherlands)

    te Wierike, Sanne C. M.; de Jong, Mark C.; Tromp, Eveline J. Y.; Vuijk, Pieter J.; Lemmink, Koen A. P. M.; Malina, Robert M.; Elferink-Gemser, Marije T.; Visscher, Chris

    te Wierike, SCM, de Jong, MC, Tromp, EJY, Vuijk, PJ, Lemmink, KAPM, Malina, RM, Elferink-Gemser, MT, and Visscher, C. Development of repeated sprint ability in talented youth basketball players. J Strength Cond Res 28(4): 928-934, 2014-Factors affecting repeated sprint ability (RSA) were evaluated

  15. Effects of dry-land vs. resisted- and assisted-sprint exercises on swimming sprint performances.

    Science.gov (United States)

    Girold, Sébastien; Maurin, Didier; Dugué, Benoit; Chatard, Jean-Claude; Millet, Grégoire

    2007-05-01

    This study was undertaken to compare the effects of dry-land strength training with a combined in-water resisted- and assisted-sprint program in swimmer athletes. Twenty-one swimmers from regional to national level participated in this study. They were randomly assigned to 3 groups: the strength (S) group that was involved in a dry-land strength training program where barbells were used, the resisted- and assisted-sprint (RAS) group that got involved in a specific water training program where elastic tubes were used to generate resistance and assistance while swimming, and the control (C) group which was involved in an aerobic cycling program. During 12 weeks, the athletes performed 6 training sessions per week on separate days. All of them combined the same aerobic dominant work for their basic training in swimming and running with their specific training. Athletes were evaluated 3 times: before the training program started, after 6 weeks of training, and at the end of the training program. The outcome values were the strength of the elbow flexors and extensors evaluated using an isokinetic dynamometer, and the speed, stroke rate, stroke length, and stroke depth observed during a 50-meter sprint. No changes were observed after 6 weeks of training. At the end of the training period, we observed significant increases in swimming velocity, and strength of elbow flexors and extensors both in the S and RAS groups. However, stroke depth decreased both in the S and RAS groups. Stroke rate increased in the RAS but not in the S group. However, no significant differences in the swimming performances between the S and RAS groups were observed. No significant changes occurred in C. Altogether, programs combining swimming with dry-land strength or with in-water resisted- and assisted-sprint exercises led to a similar gain in sprint performance and are more efficient than traditional swimming training methods alone.

  16. Paralympic Sprint Performance Between 1992 and 2012.

    Science.gov (United States)

    Grobler, Lara; Ferreira, Suzanne; Terblanche, Elmarie

    2015-11-01

    The Paralympic Games have undergone many changes since their inception in 1960, one being the advances made in running-specific prostheses (RSPs) for track athletes with lower-limb amputations. To investigate the sprinting-performance changes in athletes with lower-limb amputations since 1992 to assess whether the influence of developments in RSP technology is evident. The results of the Olympic and Paralympic Games ranging between 1992 and 2012 for the 100-m and 200-m were collected, and performance trends, percentage change in performance, and competition density (CD) were calculated. The results indicate that the greatest performance increases were seen in athletes with lower-limb amputations (T42 = 26%, T44 = 14%). These performance improvements were greater than for Olympic athletes (Paralympic athletes from other selected classes (Paralympic sprint performances, RSP technology has played a noteworthy role in the progression of performances of athletes with amputations. It is also hypothesized that the difference in the performance improvements between the T42 and T44 classes is due to the level of disability and therefore the extent to which technology is required to enable locomotion. It is evident that RSP technology has played a significant role in the progression of performances in athletes with lower-limb amputations.

  17. Pareto-Optimal Model Selection via SPRINT-Race.

    Science.gov (United States)

    Zhang, Tiantian; Georgiopoulos, Michael; Anagnostopoulos, Georgios C

    2018-02-01

    In machine learning, the notion of multi-objective model selection (MOMS) refers to the problem of identifying the set of Pareto-optimal models that optimize by compromising more than one predefined objectives simultaneously. This paper introduces SPRINT-Race, the first multi-objective racing algorithm in a fixed-confidence setting, which is based on the sequential probability ratio with indifference zone test. SPRINT-Race addresses the problem of MOMS with multiple stochastic optimization objectives in the proper Pareto-optimality sense. In SPRINT-Race, a pairwise dominance or non-dominance relationship is statistically inferred via a non-parametric, ternary-decision, dual-sequential probability ratio test. The overall probability of falsely eliminating any Pareto-optimal models or mistakenly returning any clearly dominated models is strictly controlled by a sequential Holm's step-down family-wise error rate control method. As a fixed-confidence model selection algorithm, the objective of SPRINT-Race is to minimize the computational effort required to achieve a prescribed confidence level about the quality of the returned models. The performance of SPRINT-Race is first examined via an artificially constructed MOMS problem with known ground truth. Subsequently, SPRINT-Race is applied on two real-world applications: 1) hybrid recommender system design and 2) multi-criteria stock selection. The experimental results verify that SPRINT-Race is an effective and efficient tool for such MOMS problems. code of SPRINT-Race is available at https://github.com/watera427/SPRINT-Race.

  18. Characteristics of sprint performance in college football players.

    Science.gov (United States)

    Brechue, William F; Mayhew, Jerry L; Piper, Fontaine C

    2010-05-01

    To investigate sprinting strategy, acceleration and velocity patterns were determined in college football players (n = 61) during performance of a 9.1-, 36.6-, and 54.9-m sprints. Acceleration and velocity were determined at 9.1-m intervals during each sprint. Lower-body strength and power were evaluated by 1 repetition maximum (1-RM) squat, power clean, jerk, vertical jump, standing long jump, and standing triple jump. Sprint times averaged 1.78 +/- 0.11 seconds (9.1 m), 5.18 +/- 0.35 seconds (36.6 m), and 7.40 +/- 0.53 seconds. Acceleration peaked at 9.1 m (2.96 +/- 0.44 m x s(-2)), was held constant at 18.3 m (3.55 +/- 0.0.94 m x s(-2)), and was negative at 27.4 m (-1.02 +/- 0.72 m x s(-2)). Velocity peaked at 18.3 m (8.38 +/- 0.65 m x s(-2)) and decreased slightly, but significantly at 27.4 m (7.55 +/- 0.66 m x s(-2)), associated with the negative acceleration. Measures of lower-body strength were significantly related to acceleration, velocity, and sprint performance only when corrected for body mass. Lower-body strength/BM and power correlated highest with 36.6-m time (rs = -0.55 to -0.80) and with acceleration (strength r = 0.67-0.49; power r = 0.73-0.81) and velocity (strength r = 0.68-0.53; power r = 0.74-0.82) at 9.1 m. Sprint times and strength per body mass were significantly lower in lineman compared with linebackers-tight ends and backs. The acceleration and velocity patterns were the same for each position group, and differences in sprint time were determined by the magnitude of acceleration and velocity at 9.1 and 18.3 m. Sprint performance in football players is determined by a rapid increase in acceleration (through 18.3 m) and a high velocity maintained throughout the sprint and is independent of position played. The best sprint performances (independent of sprint distance) appear to be related to the highest initial acceleration (through 18.3 m) and highest attained and maintained velocity. Strength relative to body mass and power appears to

  19. Prediction of Tennis Performance in Junior Elite Tennis Players

    Directory of Open Access Journals (Sweden)

    Tamara Kramer, Barbara C.H. Huijgen, Marije T. Elferink-Gemser, Chris Visscher

    2017-03-01

    Full Text Available Predicting current and future tennis performance can lead to improving the development of junior tennis players. The aim of this study is to investigate whether age, maturation, or physical fitness in junior elite tennis players in U13 can explain current and future tennis performance. The value of current tennis performance for future tennis performance is also investigated. A total of 86 junior elite tennis players (boys, n = 44; girls, n = 42 U13 (aged: 12.5 ± 0.3 years, and followed to U16, took part in this study. All players were top-30 ranked on the Dutch national ranking list at U13, and top-50 at U16. Age, maturation, and physical fitness, were measured at U13. A principal component analysis was used to extract four physical components from eight tests (medicine ball throwing overhead and reverse, ball throwing, SJ, CMJas, Sprint 5 and 10 meter, and the spider test. The possible relationship of age, maturation, and the physical components; “upper body power”, “lower body power”, “speed”, and “agility” with tennis performance at U13 and U16 was analyzed. Tennis performance was measured by using the ranking position on the Dutch national ranking list at U13 and U16. Regression analyses were conducted based on correlations between variables and tennis performance for boys and girls, separately. In boys U13, positive correlations were found between upper body power and tennis performance (R2 is 25%. In girls, positive correlations between maturation and lower body power with tennis performance were found at U13. Early maturing players were associated with a better tennis performance (R2 is 15%. In girls U16, only maturation correlated with tennis performance (R2 is 13%; later-maturing girls at U13 had better tennis performances at U16. Measuring junior elite tennis players at U13 is important for monitoring their development. These measurements did not predict future tennis performance of junior elite tennis players three

  20. Giving students the run of sprinting models

    Science.gov (United States)

    Heck, André; Ellermeijer, Ton

    2009-11-01

    A biomechanical study of sprinting is an interesting task for students who have a background in mechanics and calculus. These students can work with real data and do practical investigations similar to the way sports scientists do research. Student research activities are viable when the students are familiar with tools to collect and work with data from sensors and video recordings and with modeling tools for comparing simulation and experimental results. This article describes a multipurpose system, named COACH, that offers a versatile integrated set of tools for learning, doing, and teaching mathematics and science in a computer-based inquiry approach. Automated tracking of reference points and correction of perspective distortion in videos, state-of-the-art algorithms for data smoothing and numerical differentiation, and graphical system dynamics based modeling are some of the built-in techniques that are suitable for motion analysis. Their implementation and their application in student activities involving models of running are discussed.

  1. A sled push stimulus potentiates subsequent 20-m sprint performance.

    Science.gov (United States)

    Seitz, Laurent B; Mina, Minas A; Haff, G Gregory

    2017-08-01

    The objective of this study was to examine the potentiating effects of performing a single sprint-style sled push on subsequent unresisted 20m sprint performance. Randomized crossover design. Following a familiarization session, twenty rugby league players performed maximal unresisted 20m sprints before and 15s, 4, 8 and 12min after a single sled push stimulus loaded with either 75 or 125% body mass. The two sled push conditions were performed in a randomized order over a one-week period. The fastest sprint time recorded before each sled push was compared to that recorded at each time point after to determine the post-activation potentiation (PAP) effect. After the 75% body mass sled push, sprint time was 0.26±1.03% slower at the 15s time point (effect size [ES]=0.07) but faster at the 4 (-0.95±2.00%; ES=-0.22), 8 (-1.80±1.43%; ES=-0.42) and 12 (-1.54±1.54%; ES=-0.36)min time points. Sprint time was slower at all the time points after the 125% body mass sled (1.36±2.36%-2.59±2.90%; ESs=0.34-0.64). Twenty-meter sprint performance is potentiated 4-12min following a sled push loaded with 75% body mass while it is impaired after a 125% body mass sled. These results are of great importance for coaches seeking to potentiate sprint performance with the sled push exercise. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  2. Hand Grip Strength Vs. Sprint Effectiveness in Amputee Soccer Players.

    Science.gov (United States)

    Wieczorek, Marta; Wiliński, Wojciech; Struzik, Artur; Rokita, Andrzej

    2015-11-22

    Amputee soccer is one of the types of soccer designed for the disabled, especially those who have undergone amputations, as well as those with extremity dysfunction. The objective of the study was to find the relationship between hand grip strength and sprint time in amputee soccer players. Thirteen field amputee soccer players participated in the study. A SAEHAN hydraulic hand dynamometer manufactured by Jamar was used for hand grip strength measurements. The sprint running test was conducted over a distance of 30 m. The Fusion Smart Speed System was employed for running time measurements. No statistically significant relationships were found between hand grip strength of the left or right hand, and sprint times over 1, 5, 10, 15, 20, 25 and 30 m. Analysis of the running velocity curve of the subjects showed an interesting profile characterized by a 15 meter-long acceleration phase and a significant velocity increase over a distance of 20 - 25 m. The study suggests that there is no relationship between hand grip strength and sprint effectiveness in amputee soccer players. The specificity of locomotion with the use of elbow crutches among elite Polish amputee soccer players probably accounts for the profile of the sprint velocity curve. Extension of the acceleration phase in the sprint run and a velocity increase in the subsequent part of the run were observed.

  3. Hand Grip Strength Vs. Sprint Effectiveness in Amputee Soccer Players

    Directory of Open Access Journals (Sweden)

    Wieczorek Marta

    2015-12-01

    Full Text Available Amputee soccer is one of the types of soccer designed for the disabled, especially those who have undergone amputations, as well as those with extremity dysfunction. The objective of the study was to find the relationship between hand grip strength and sprint time in amputee soccer players. Thirteen field amputee soccer players participated in the study. A SAEHAN hydraulic hand dynamometer manufactured by Jamar was used for hand grip strength measurements. The sprint running test was conducted over a distance of 30 m. The Fusion Smart Speed System was employed for running time measurements. No statistically significant relationships were found between hand grip strength of the left or right hand, and sprint times over 1, 5, 10, 15, 20, 25 and 30 m. Analysis of the running velocity curve of the subjects showed an interesting profile characterized by a 15 meter-long acceleration phase and a significant velocity increase over a distance of 20 – 25 m. The study suggests that there is no relationship between hand grip strength and sprint effectiveness in amputee soccer players. The specificity of locomotion with the use of elbow crutches among elite Polish amputee soccer players probably accounts for the profile of the sprint velocity curve. Extension of the acceleration phase in the sprint run and a velocity increase in the subsequent part of the run were observed.

  4. Acute and Time-Course Effects of Traditional and Dynamic Warm-Up Routines in Young Elite Junior Tennis Players.

    Directory of Open Access Journals (Sweden)

    Francisco Ayala

    Full Text Available Despite the large number of studies that have examined the acute effects of different warm up modalities (WU on physical performance, none of them have documented the time course of potential performance recovery in tennis players. The aim of this study was twofold: (a to analyze and compare the acute effects of two different WU modalities (traditional WU [TWU] and dynamic WU [DWU] on physical performance (i.e., CMJ, sprint, serve speed and accuracy in elite junior players, as well as (b to monitor the time course of any WU-induced changes after 30 and 60 min of simulated match-play. Twelve junior elite players completed both WUs modalities (TWU and DWU in a counterbalanced order on separate days. In each experimental session, counter movement jump (CMJ, 20-m sprint, tennis serve speed and accuracy tests were performed before (immediately after TWU or DWU during (30 min and after 60 min of a simulated match play. Measures were compared via four factorial (WU intervention and time repeated measures ANOVAs. There were main effects of WU (TWU and DWU throughout the time for all the variables analysed. The results indicate that DWU routine led to significantly faster 20 m sprint times and higher CMJs as well as faster and more accurate tennis serves at both post warm-up and 30 min match-play testing moments in comparison with the scores reported by the TWU routine (p 75-99%. No significant intergroup differences were found at 60-min match-play testing moment in any variable (except for the 20 m sprint. Therefore, the findings of this study recommend for optimal performance in these elite tennis players, DWU routines should be performed prior to formal training and competition rather than TWU routines.

  5. Postactivation potentiation of sprint acceleration performance using plyometric exercise.

    Science.gov (United States)

    Turner, Anthony P; Bellhouse, Sam; Kilduff, Liam P; Russell, Mark

    2015-02-01

    Postactivation potentiation (PAP), an acute and temporary enhancement of muscular performance resulting from previous muscular contraction, commonly occurs after heavy resistance exercise. However, this method of inducing PAP has limited application to the precompetition practices (e.g., warm-up) of many athletes. Very few studies have examined the influence of plyometric activity on subsequent performance; therefore, we aimed to examine the influence of alternate-leg bounding on sprint acceleration performance. In a randomized crossover manner, plyometric-trained men (n = 23) performed seven 20-m sprints (with 10-m splits) at baseline, ∼15 seconds, 2, 4, 8, 12, and 16 minutes after a walking control (C) or 3 sets of 10 repetitions of alternate-leg bounding using body mass (plyometric, P) and body mass plus 10% (weighted plyometric, WP). Mean sprint velocities over 10 and 20 m were similar between trials at baseline. At ∼15 seconds, WP impaired 20-m sprint velocity by 1.4 ± 2.5% when compared with C (p = 0.039). Thereafter, 10- and 20-m sprint velocities improved in WP at 4 minutes (10 m: 2.2 ± 3.1%, p = 0.009; 20 m: 2.3 ± 2.6%, p = 0.001) and 8 minutes (10 m: 2.9 ± 3.6%, p = 0.002; 20 m: 2.6 ± 2.8%, p = 0.001) compared with C. Improved 10-m sprint acceleration performance occurred in P at 4 minutes (1.8 ± 3.3%, p = 0.047) relative to C. Therefore, sprint acceleration performance is enhanced after plyometric exercise providing adequate recovery is given between these activities; however, the effects may differ according to whether additional load is applied. This finding presents a practical method to enhance the precompetition practices of athletes.

  6. Development of a neuromuscular electrical stimulation protocol for sprint training.

    Science.gov (United States)

    Russ, David W; Clark, Brian C; Krause, Jodi; Hagerman, Fredrick C

    2012-09-01

    Sprint training is associated with several beneficial adaptations in skeletal muscle, including an enhancement of sarcoplasmic reticulum (SR) Ca(2+) release. Unfortunately, several patient populations (e.g., the elderly, those with cardiac dysfunction) that might derive great benefit from sprint exercise are unlikely to tolerate it. The purpose of this report was to describe the development of a tolerable neuromuscular electrical stimulation (NMES) protocol that induces skeletal muscle adaptations similar to those observed with sprint training. Our NMES protocol was modeled after a published sprint exercise protocol and used a novel electrode configuration and stimulation sequence to provide adequate training stimulus while maintaining subject tolerance. Nine young, healthy subjects (four men) began and completed the training protocol of the knee extensor muscles. All subjects completed the protocol, with ratings of discomfort far less than those reported in studies of traditional NMES. Training induced significant increases in SR Ca(2+) release and citrate synthase activity (~16% and 32%, respectively), but SR Ca(2+) uptake did not change. The percentage of myosin heavy chain IIx isoform was decreased significantly after training. At the whole muscle level, neither central activation nor maximum voluntary isometric contraction force were significantly altered, although isometric force did exhibit a trend toward an increase (~3%, P = 0.055). Surprisingly, the NMES training produced a significant increase in muscle cross-sectional area (~3%, P = 0.04). It seems that an appropriately designed NMES protocol can mimic many of the benefits of sprint exercise training, with a low overall time commitment and training volume. These findings suggest that NMES has the potential to bring the benefits of sprint exercise to individuals who are unable to tolerate traditional sprint training.

  7. Effect of heavy back squats on repeated sprint performance in trained men.

    Science.gov (United States)

    Duncan, M J; Thurgood, G; Oxford, S W

    2014-04-01

    This study examined the impact of post activation potentiation on repeated sprint performance in trained Rugby Union players. Ten, male, professional Rugby Union players (mean age=25.2±5.02 years) performed 7, 30-meter sprints, separated by 25 seconds, 4 minutes following back squats (90% 1 repetition maximum) or a control condition performed in a counterbalanced order. Significant condition X sprint interactions for 10-meter (P=0.02) and 30-meter (P=0.05) indicated that times were significantly faster in the PAP condition for sprints 5, 6 and 7 across both distances. Fatigue rate was also significantly lower in the PAP condition for 10-meter (P=0.023) and 30-meter (P=0.006) sprint running speed. This study evidences that a heavy resistance exercise stimulus administered four minutes prior to repeated sprints can offset the decline in sprint performance seen during subsequent maximal sprinting over 10 and 30-meters in Rugby Union players.

  8. The Effects of Muscular Fatigue on the Kinetics of Sprint Running.

    Science.gov (United States)

    Sprague, Paul; Mann, Ralph V.

    1983-01-01

    To compare the kinematic and kinetic effects of fatigue on the biomechanics of sprint running, male subjects were filmed performing a short maximal exertion sprint and a long fatiguing sprint. Observable differences in the productive muscular activity of the better and the poorer sprinters occurred during the ground-phase of their strides.…

  9. The effect of hamstring flexibility on peak hamstring muscle strain in sprinting

    Directory of Open Access Journals (Sweden)

    Xianglin Wan

    2017-09-01

    Conclusion: A potential for hamstring injury exists during the late swing phase of sprinting. Peak hamstring muscle strains in sprinting are negatively correlated to hamstring flexibility across individuals. The magnitude of peak muscle strains is different among hamstring muscles in sprinting, which may explain the different injury rate among hamstring muscles.

  10. Pupil Behavior in Junior Classrooms

    Science.gov (United States)

    Boydell, D.

    1975-01-01

    The purpose of the exploratory study reported here was to investigate the nature of children's behavior in unstreamed, informal, junior classrooms where the children sit in small groups and the incidence of private teacher talk to small groups and individual children is high. (Author)

  11. 300 Junior Novel Anticipation Guides

    Science.gov (United States)

    Polette, Nancy

    2006-01-01

    In this book, the author has created reproducible anticipation guides to 300 popular junior novels (grades 4-8) ranging from classics like Ben and Me and Cricket in Times Square to the current award winner, Kira, Kira. The book consists of 300 reproducible sets of open ended values questions to pique the interest of readers. Librarians and…

  12. Junior College Faculty Job Satisfaction.

    Science.gov (United States)

    Frankel, Joanne

    Some of the research done to date concerning job satisfaction of junior college faculty is reviewed in this "Brief." Part I of the "Brief" describes four frameworks that have been applied to the analysis of job satisfaction: the traditional approach, the two-factor approach, the need hierarchy, and the cognitive dissonance approach. Part II…

  13. Junior PC-Kørekort

    DEFF Research Database (Denmark)

    Hansbøl, Mikala; Mathiasen, Helle

    udviklingsprojekt med forsøg med DANSK IT's Junior PC-kørekort® som metode og redskab til at evaluere og dokumentere elevernes IT-kompetencer. Projektet blev gennemført i perioden fra 2002-2003 og afsluttet i foråret 2003. Rapporten er baseret på kvalitative case studier af elever og læreres arbejde med Junior PC......-kørekort® prøverne. DANSK IT's Junior PC-kørekort® kan betragtes som et forsøg på at etablere en bestemt fælleskulturel tilgang til elevernes IT-kompetencer i folkeskolen. Ud fra et situeret læringsperspektiv problematiserer rapporten anvendelsen af de standardiserede prøver som metode til at dokumentere og evaluere...... elevernes IT-kompetencer. Rapporten (2MB) fylder 80 sider ekskl. bilag. Bemærk, at forskningsrapporten handler om Dansk IT's Junior PC-kørekort - ikke at forveksle med det IT-bevis for folkeskolens elever, som Undevisningsministeriet har udviklet. Dette IT-bevis koncept skiftede navn i januar 2004, hvor...

  14. Holography in the Junior High.

    Science.gov (United States)

    Tomaszkiewicz, Frank

    1988-01-01

    Examines the use of holography in the art technology program of a junior high school. Characterizing holography as a valuable artistic experience and discovery experience and stressing the importance of student interest and involvement, the author discusses the necessary equipment for the project and includes two diagrams of a holographic setup.…

  15. High Speed Running and Sprinting Profiles of Elite Soccer Players

    Directory of Open Access Journals (Sweden)

    Miñano-Espin Javier

    2017-08-01

    Full Text Available Real Madrid was named as the best club of the 20th century by the International Federation of Football History and Statistics. The aim of this study was to compare if players from Real Madrid covered shorter distances than players from the opposing team. One hundred and forty-nine matches including league, cup and UEFA Champions League matches played by the Real Madrid were monitored during the 2001-2002 to the 2006-2007 seasons. Data from both teams (Real Madrid and the opponent were recorded. Altogether, 2082 physical performance profiles were examined, 1052 from the Real Madrid and 1031 from the opposing team (Central Defenders (CD = 536, External Defenders (ED = 491, Central Midfielders (CM = 544, External Midfielders (EM = 233, and Forwards (F = 278. Match performance data were collected using a computerized multiple-camera tracking system (Amisco Pro®, Nice, France. A repeated measures analysis of variance (ANOVA was performed for distances covered at different intensities (sprinting (>24.0 km/h and high-speed running (21.1-24.0 km/h and the number of sprints (21.1-24.0 km/h and >24.0 km/h during games for each player sectioned under their positional roles. Players from Real Madrid covered shorter distances in high-speed running and sprint than players from the opposing team (p 0.01 from Real Madrid covered shorter distances in high-intensity running and sprint and performed less sprints than their counterparts. Finally, no differences were found in the high-intensity running and sprint distances performed by players from Real Madrid depending on the quality of the opposition.

  16. Comparison of Sprint Fidelis and Riata defibrillator lead failure rates.

    Science.gov (United States)

    Fazal, Iftikhar A; Shepherd, Ewen J; Tynan, Margaret; Plummer, Christopher J; McComb, Janet M

    2013-09-30

    Sprint Fidelis and Riata defibrillator leads are prone to early failure. Few data exist on the comparative failure rates and mortality related to lead failure. The aims of this study were to determine the failure rate of Sprint Fidelis and Riata leads, and to compare failure rates and mortality rates in both groups. Patients implanted with Sprint Fidelis leads and Riata leads at a single centre were identified and in July 2012, records were reviewed to ascertain lead failures, deaths, and relationship to device/lead problems. 113 patients had Sprint Fidelis leads implanted between June 2005 and September 2007; Riata leads were implanted in 106 patients between January 2003 and February 2008. During 53.0 ± 22.3 months of follow-up there were 13 Sprint Fidelis lead failures (11.5%, 2.60% per year) and 25 deaths. Mean time to failure was 45.1 ± 15.5 months. In the Riata lead cohort there were 32 deaths, and 13 lead failures (11.3%, 2.71% per year) over 54.8 ± 26.3 months follow-up with a mean time to failure of 53.5 ± 24.5 months. There were no significant differences in the lead failure-free Kaplan-Meier survival curve (p=0.77), deaths overall (p=0.17), or deaths categorised as sudden/cause unknown (p=0.54). Sprint Fidelis and Riata leads have a significant but comparable failure rate at 2.60% per year and 2.71% per year of follow-up respectively. The number of deaths in both groups is similar and no deaths have been identified as being related to lead failure in either cohort. Copyright © 2012. Published by Elsevier Ireland Ltd.

  17. Carbohydrate mouth rinse does not improve repeated sprint performance

    Directory of Open Access Journals (Sweden)

    Leandro Ricardo Altimari

    2013-09-01

    Full Text Available The objective of this study was to evaluate the effect of a carbohydrate mouth rinse on the repeated sprint ability (RSA of young soccer players. Nine youth soccer players (15.0 ± 1.5 years; 60.7 ± 4.84 kg; 1.72 ± 0.05 m; 20.5 ± 1.25 kg/m2 were selected. The athletes were submitted to an RSA test consisting of six sprints of 40 m (going/return = 20 m + 20 m, separated by 20 s of passive recovery, under three experimental conditions: carbohydrate mouth rinse (CHO or placebo (PLA and control (CON. The mouth rinses containing CHO or PLA were administered 5 min and immediately before the beginning of the test in doses of 100 mL. The best sprint time (RSAbest, mean sprint time (RSAmean, and drop-off in sprint performance (fatigue index were determined for the different treatments. One-not identify significant differences (p> 0.05 in RSAbest (CHO way ANOVA for repeated measures did = 7.30 ± 0.31 s; PLA = 7.30 ± 0.30 s; CON = 7.26 ±0.16 s, RSA mean (CHO = 7.71 ± 0.30 s; PLA = 7.71 ± 0.25 s; CON = 7.66 ± 0.24s, or fatigue index (CHO = 5.58 ± 2.16%; PLA = 5.77 ± 3.04%; CON = 5.55 ±3.72%. The results suggest that a carbohydrate mouth rinse does not improve the repeated sprint performance of young soccer players.

  18. Mechanical Alterations Associated with Repeated Treadmill Sprinting under Heat Stress.

    Directory of Open Access Journals (Sweden)

    Olivier Girard

    Full Text Available Examine the mechanical alterations associated with repeated treadmill sprinting performed in HOT (38°C and CON (25°C conditions.Eleven recreationally active males performed a 30-min warm-up followed by three sets of five 5-s sprints with 25-s recovery and 3-min between sets in each environment. Constant-velocity running for 1-min at 10 and 20 km.h-1 was also performed prior to and following sprinting.Mean skin (37.2±0.7 vs. 32.7±0.8°C; P<0.001 and core (38.9±0.2 vs. 38.8±0.3°C; P<0.05 temperatures, together with thermal comfort (P<0.001 were higher following repeated sprinting in HOT vs. CON. Step frequency and vertical stiffness were lower (-2.6±1.6% and -5.5±5.5%; both P<0.001 and contact time (+3.2±2.4%; P<0.01 higher in HOT for the mean of sets 1-3 compared to CON. Running distance per sprint decreased from set 1 to 3 (-7.0±6.4%; P<0.001, with a tendency for shorter distance covered in HOT vs. CON (-2.7±3.4%; P = 0.06. Mean vertical (-2.6±5.5%; P<0.01, horizontal (-9.1±4.4%; P<0.001 and resultant ground reaction forces (-3.0±2.8%; P<0.01 along with vertical stiffness (-12.9±2.3%; P<0.001 and leg stiffness (-8.4±2.7%; P<0.01 decreased from set 1 to 3, independently of conditions. Propulsive power decreased from set 1 to 3 (-16.9±2.4%; P<0.001, with lower propulsive power values in set 2 (-6.6%; P<0.05 in HOT vs. CON. No changes in constant-velocity running patterns occurred between conditions, or from pre-to-post repeated-sprint exercise.Thermal strain alters step frequency and vertical stiffness during repeated sprinting; however without exacerbating mechanical alterations. The absence of changes in constant-velocity running patterns suggests a strong link between fatigue-induced velocity decrements during sprinting and mechanical alterations.

  19. Mechanical Alterations Associated with Repeated Treadmill Sprinting under Heat Stress

    Science.gov (United States)

    Brocherie, Franck; Morin, Jean-Benoit; Racinais, Sébastien; Millet, Grégoire P.; Périard, Julien D.

    2017-01-01

    Purpose Examine the mechanical alterations associated with repeated treadmill sprinting performed in HOT (38°C) and CON (25°C) conditions. Methods Eleven recreationally active males performed a 30-min warm-up followed by three sets of five 5-s sprints with 25-s recovery and 3-min between sets in each environment. Constant-velocity running for 1-min at 10 and 20 km.h-1 was also performed prior to and following sprinting. Results Mean skin (37.2±0.7 vs. 32.7±0.8°C; P<0.001) and core (38.9±0.2 vs. 38.8±0.3°C; P<0.05) temperatures, together with thermal comfort (P<0.001) were higher following repeated sprinting in HOT vs. CON. Step frequency and vertical stiffness were lower (-2.6±1.6% and -5.5±5.5%; both P<0.001) and contact time (+3.2±2.4%; P<0.01) higher in HOT for the mean of sets 1–3 compared to CON. Running distance per sprint decreased from set 1 to 3 (-7.0±6.4%; P<0.001), with a tendency for shorter distance covered in HOT vs. CON (-2.7±3.4%; P = 0.06). Mean vertical (-2.6±5.5%; P<0.01), horizontal (-9.1±4.4%; P<0.001) and resultant ground reaction forces (-3.0±2.8%; P<0.01) along with vertical stiffness (-12.9±2.3%; P<0.001) and leg stiffness (-8.4±2.7%; P<0.01) decreased from set 1 to 3, independently of conditions. Propulsive power decreased from set 1 to 3 (-16.9±2.4%; P<0.001), with lower propulsive power values in set 2 (-6.6%; P<0.05) in HOT vs. CON. No changes in constant-velocity running patterns occurred between conditions, or from pre-to-post repeated-sprint exercise. Conclusions Thermal strain alters step frequency and vertical stiffness during repeated sprinting; however without exacerbating mechanical alterations. The absence of changes in constant-velocity running patterns suggests a strong link between fatigue-induced velocity decrements during sprinting and mechanical alterations. PMID:28146582

  20. Differences in hamstring activation characteristics between the acceleration and maximum-speed phases of sprinting.

    Science.gov (United States)

    Higashihara, Ayako; Nagano, Yasuharu; Ono, Takashi; Fukubayashi, Toru

    2018-06-01

    This study aimed to investigate activation characteristics of the biceps femoris long head (BFlh) and semitendinosus (ST) muscles during the acceleration and maximum-speed phases of sprinting. Lower-extremity kinematics and electromyographic (EMG) activities of the BFlh and ST muscles were examined during the acceleration sprint and maximum-speed sprint in 13 male sprinters during an overground sprinting. Differences in hamstring activation during each divided phases and in the hip and knee joint angles and torques at each time point of the sprinting gait cycle were determined between two sprints. During the early stance of the acceleration sprint, the hip extension torque was significantly greater than during the maximum-speed sprint, and the relative EMG activation of the BFlh muscle was significantly higher than that of the ST muscle. During the late stance and terminal mid-swing of maximum-speed sprint, the knee was more extended and a higher knee flexion moment was observed compared to the acceleration sprint, and the ST muscle showed higher activation than that of the BFlh. These results indicate that the functional demands of the medial and lateral hamstring muscles differ between two different sprint performances.

  1. EFFECTS OF A SAND RUNNING SURFACE ON THE KINEMATICS OF SPRINTING AT MAXIMUM VELOCITY

    Directory of Open Access Journals (Sweden)

    P E Alcaraz

    2011-05-01

    Full Text Available Performing sprints on a sand surface is a common training method for improving sprint-specific strength. For maximum specificity of training the athlete’s movement patterns during the training exercise should closely resemble those used when performing the sport. The aim of this study was to compare the kinematics of sprinting at maximum velocity on a dry sand surface to the kinematics of sprinting on an athletics track. Five men and five women participated in the study, and flying sprints over 30 m were recorded by video and digitized using biomechanical analysis software. We found that sprinting on a sand surface was substantially different to sprinting on an athletics track. When sprinting on sand the athletes tended to ‘sit’ during the ground contact phase of the stride. This action was characterized by a lower centre of mass, a greater forward lean in the trunk, and an incomplete extension of the hip joint at take-off. We conclude that sprinting on a dry sand surface may not be an appropriate method for training the maximum velocity phase in sprinting. Although this training method exerts a substantial overload on the athlete, as indicated by reductions in running velocity and stride length, it also induces detrimental changes to the athlete’s running technique which may transfer to competition sprinting.

  2. Development of repeated sprint ability in talented youth basketball players

    NARCIS (Netherlands)

    te Wierike, Simon; Lemmink, Koen; de Jong, M.C.; Tromp, E.J.; Vuijk, P.J.; Malina, R.M.; Elferink-Gemser, Marije; Visscher, Chris

    2013-01-01

    Factors affecting repeated sprint ability (RSA) were evaluated in a mixed-longitudinal sample of 48 elite basketball players 14 to 19 years of age (16.1±1.7 years). Players were observed on six occasions during the 2008-2009 and 2009-2010 seasons. Three basketball-specific field tests were

  3. Neuromuscular adjustments of the quadriceps muscle after repeated cycling sprints.

    Directory of Open Access Journals (Sweden)

    Olivier Girard

    Full Text Available PURPOSE: This study investigated the supraspinal processes of fatigue of the quadriceps muscle in response to repeated cycling sprints. METHODS: Twelve active individuals performed 10 × 6-s "all-out" sprints on a cycle ergometer (recovery = 30 s, followed 6 min later by 5 × 6-s sprints (recovery = 30 s. Transcranial magnetic and electrical femoral nerve stimulations during brief (5-s and sustained (30-s isometric contractions of the knee extensors were performed before and 3 min post-exercise. RESULTS: Maximal strength of the knee extensors decreased during brief and sustained contractions (~11% and 9%, respectively; P0.05. While cortical voluntary activation declined (P 40% reduced (P<0.001 following exercise. CONCLUSION: The capacity of the motor cortex to optimally drive the knee extensors following a repeated-sprint test was shown in sustained, but not brief, maximal isometric contractions. Additionally, peripheral factors were largely involved in the exercise-induced impairment in neuromuscular function, while corticospinal excitability was well-preserved.

  4. Supervisory Presentation for Research, Information, Integration and Testing (SPRINT)

    Science.gov (United States)

    2015-03-29

    in Microsoft Visual Studio and several third party developer libraries (See Figure 4). All distributed laboratory sites have similar hardware...Testing (SPRINT). 15. SUBJECT TERMS Supervisory Control, Multi-Modal Interfaces, Scalable Interfaces, Advanced Visualization , Augmented Symbology 16...23 Figure 9. Fusion Visual Framework Components

  5. Development of repeated sprint ability in talented youth basketball players.

    NARCIS (Netherlands)

    Koen A.P.M. Lemmink; P.J. Vuijk; S.C. te Wierike; C. Visscher; M.T. Elferink-Gemser; M.C. de Jong; R.M. Malina; E.J. Tromp

    2013-01-01

    Factors affecting repeated sprint ability (RSA) were evaluated in a mixed-longitudinal sample of 48 elite basketball players 14 to 19 years of age (16.1±1.7 years). Players were observed on six occasions during the 2008-2009 and 2009-2010 seasons. Three basketball-specific field tests were

  6. Kinematic analysis of competitive sprinting | Ansari | African Journal ...

    African Journals Online (AJOL)

    The results of the study showed that the kinematic variables i.e. knee angle, hip angle, ankle angle, shoulder rotation and extension had a significant influence on sprinting style. The results indicated that the kinematic variables of running style, knee angle at landing, hip flexion, ankle angle at landing, ankle angle at take-off, ...

  7. Sprint-based exercise and cognitive function in adolescents

    Directory of Open Access Journals (Sweden)

    Simon B. Cooper

    2016-12-01

    Full Text Available Moderate intensity exercise has been shown to enhance cognition in an adolescent population, yet the effect of high-intensity sprint-based exercise remains unknown and was therefore examined in the present study. Following ethical approval and familiarisation, 44 adolescents (12.6 ± 0.6 y completed an exercise (E and resting (R trial in a counter-balanced, randomised crossover design. The exercise trial comprised of 10 × 10 s running sprints, interspersed by 50 s active recovery (walking. A battery of cognitive function tests (Stroop, Digit Symbol Substitution (DSST and Corsi blocks tests were completed 30 min pre-exercise, immediately post-exercise and 45 min post-exercise. Data were analysed using mixed effect models with repeated measures. Response times on the simple level of the Stroop test were significantly quicker 45 min following sprint-based exercise (R: 818 ± 33 ms, E: 772 ± 26 ms; p = 0.027 and response times on the complex level of the Stroop test were quicker immediately following the sprint-based exercise (R: 1095 ± 36 ms, E: 1043 ± 37 ms; p = 0.038, while accuracy was maintained. Sprint-based exercise had no immediate or delayed effects on the number of items recalled on the Corsi blocks test (p = 0.289 or substitutions made during the DSST (p = 0.689. The effect of high intensity sprint-based exercise on adolescents' cognitive function was dependant on the component of cognitive function examined. Executive function was enhanced following exercise, demonstrated by improved response times on the Stroop test, whilst visuo-spatial memory and general psycho-motor speed were unaffected. These data support the inclusion of high-intensity sprint-based exercise for adolescents during the school day to enhance cognition.

  8. Attentional and visual demands for sprint performance in non-fatigued and fatigued conditions : reliability of a repeated sprint test

    NARCIS (Netherlands)

    Reininga, Inge H. F.; Lemmink, Koen A. P. M.; Diercks, Ron L.; Buizer, Arina T.; Stevens, Martin

    2010-01-01

    Background: Physical performance measures are widely used to assess physical function, providing information about physiological and biomechanical aspects of motor performance. However they do not provide insight into the attentional and visual demands for motor performance. A figure-of-eight sprint

  9. Comparison of sprinting vs non-sprinting to wean nasal continuous positive airway pressure off in very preterm infants.

    Science.gov (United States)

    Eze, N; Murphy, D; Dhar, V; Rehan, V K

    2018-02-01

    Though nasal continuous positive airway pressure (NCPAP) is commonly used for non-invasive neonatal respiratory support, the optimal method of weaning NCPAP is not established. In this prospective, two-center randomized control trial we hypothesize that gradually increasing spontaneous breathing time off NCPAP increases successful weaning from NCPAP in infants born 0.05). It took 1.3 (1 to 1.75) (median (IQR)) attempts and 7 (7 to 7) days to wean NCPAP off in the sprinting group vs 1.3 (1 to 1.75) attempts and 7 (7 to 10) days in the non-sprinting group (P>0.05). Additionally, no differences in the secondary outcomes of bronchopulmonary dysplasia, severe retinopathy of prematurity (⩾stage 3), periventricular leukomalacia and length of stay were noted between the two groups. Weaning NCPAP via sprinting or non-sprinting protocol is comparable, not only for successful weaning but also for the occurrence of common neonatal morbidities that impact the long-term outcome in premature infants (ClinicalTrials.gov number, NCT02819050).

  10. Relationships between ground reaction impulse and sprint acceleration performance in team sport athletes.

    Science.gov (United States)

    Kawamori, Naoki; Nosaka, Kazunori; Newton, Robert U

    2013-03-01

    Large horizontal acceleration in short sprints is a critical performance parameter for many team sport athletes. It is often stated that producing large horizontal impulse at each ground contact is essential for high short sprint performance, but the optimal pattern of horizontal and vertical impulses is not well understood, especially when the sprints are initiated from a standing start. This study was an investigation of the relationships between ground reaction impulses and sprint acceleration performance from a standing start in team sport athletes. Thirty physically active young men with team sport background performed 10-m sprint from a standing start, whereas sprint time and ground reaction forces were recorded during the first ground contact and at 8 m from the start. Associations between sprint time and ground reaction impulses (normalized to body mass) were determined by a Pearson's correlation coefficient (r) analysis. The 10-m sprint time was significantly (p < 0.01) correlated with net horizontal impulse (r = -0.52) and propulsive impulse (r = -0.66) measured at 8 m from the start. No significant correlations were found between sprint time and impulses recorded during the first ground contact after the start. These results suggest that applying ground reaction impulse in a more horizontal direction is important for sprint acceleration from a standing start. This is consistent with the hypothesis of training to increase net horizontal impulse production using sled towing or using elastic resistance devices, which needs to be validated by future longitudinal training studies.

  11. A comparison of the physical and anthropometric qualities explanatory of talent in the elite junior Australian football development pathway.

    Science.gov (United States)

    Woods, Carl T; Cripps, Ashley; Hopper, Luke; Joyce, Christopher

    2017-07-01

    To compare the physical and anthropometric qualities explanatory of talent at two developmental levels in junior Australian football (AF). Cross-sectional observational. From a total of 134 juniors, two developmental levels were categorised; U16 (n=50; 15.6±0.3 y), U18 (n=84; 17.4±0.5 y). Within these levels, two groups were a priori defined; talent identified (U16; n=25; 15.7±0.2 y; U18 n=42; 17.5±0.4 y), non-talent identified (U16; n=25; 15.6±0.4 y; U18; n=42; 17.3±0.6 y). Players completed seven physical and anthropometric assessments commonly utilised for talent identification in AF. Binary logistic regression models were built to identify the qualities most explanatory of talent at each level. A combination of standing height, dominant leg dynamic vertical jump height and 20m sprint time provided the most parsimonious explanation of talent at the U16 level (AICc=60.05). At the U18 level, it was a combination of body mass and 20m sprint time that provided the most parsimonious explanation of talent (AICc=111.27). Despite similarities, there appears to be distinctive differences in physical and anthropometric qualities explanatory of talent at the U16 and U18 level. Coaches may view physical and anthropometric qualities more (or less) favourably at different levels of the AF developmental pathway. Given these results, future work should implement a longitudinal design, as physical and/or anthropometric qualities may deteriorate (or emerge) as junior AF players develop. Copyright © 2016 Sports Medicine Australia. All rights reserved.

  12. Data Sprints: A Collaborative Format in Digital Controversy Mapping

    DEFF Research Database (Denmark)

    Munk, Anders Kristian; Tommaso, Venturini; Meunier, Axel

    2017-01-01

    driven by a desire to provide navigational aids to actors faced with the challenge of making sense of complicated techno-scientific problems. Natively digital media technologies have thus been re-appropriated by STS researchers specifically for the purpose of mapping controversies in a way that would...... experiences with various forms of public engagement and participation. Through a concrete reappropriation of a collaborative format that is indeed native to the digital domain - namely the hackathon - we will show how digital methods can make a difference in participatory STS research. The data sprint, as we...... in amsterdam. Through a mix of digital methods ranging from web cartography and text mining to scientometrics and social media analysis we took on questions related to climate adaptation funding, vulnerability assessment, project management, and dynamics of the international negotiations. The sprints hardwired...

  13. SPRINT RA 230: Methodology for knowledge based developments

    International Nuclear Information System (INIS)

    Wallsgrove, R.; Munro, F.

    1991-01-01

    SPRINT RA 230: A Methodology for Knowledge Based Developments, funded by the European Commission, was set up to investigate the use of KBS in the engineering industry. Its aim was to find out low KBS were currently used and what people's conceptions of them was, to disseminate current knowledge and to recommend further research into this area. A survey (by post and face to face interviews) was carried out under SPRINT RA 230 to investigate requirements for more intelligent software. In the survey we looked both at how people think about Knowledge Based Systems (KBS), what they find useful and what is not useful, and what current expertise problems or limitations of conventional software might suggest KBS solutions. (orig./DG)

  14. Determining friction and effective loading for sled sprinting.

    Science.gov (United States)

    Cross, Matt R; Tinwala, Farhan; Lenetsky, Seth; Samozino, Pierre; Brughelli, Matt; Morin, Jean-Benoit

    2017-11-01

    Understanding the impact of friction in sled sprinting allows the quantification of kinetic outputs and the effective loading experienced by the athlete. This study assessed changes in the coefficient of friction (µ k ) of a sled sprint-training device with changing mass and speed to provide a means of quantifying effective loading for athletes. A common sled equipped with a load cell was towed across an athletics track using a motorised winch under variable sled mass (33.1-99.6 kg) with constant speeds (0.1 and 0.3 m · s -1 ), and with constant sled mass (55.6 kg) and varying speeds (0.1-6.0 m · s -1 ). Mean force data were analysed, with five trials performed for each condition to assess the reliability of measures. Variables were determined as reliable (ICC > 0.99, CV friction-force and speed/coefficient of friction relationships well fitted with linear (R 2  = 0.994-0.995) and quadratic regressions (R 2  = 0.999), respectively (P friction values determined at two speeds, and the range in values from the quadratic fit (µ k  = 0.35-0.47) suggested µ k and effective loading were dependent on instantaneous speed on athletics track surfaces. This research provides a proof-of-concept for the assessment of friction characteristics during sled towing, with a practical example of its application in determining effective loading and sled-sprinting kinetics. The results clarify effects of friction during sled sprinting and improve the accuracy of loading applications in practice and transparency of reporting in research.

  15. Spinal Cord Excitability and Sprint Performance Are Enhanced by Sensory Stimulation During Cycling

    Directory of Open Access Journals (Sweden)

    Gregory E. P. Pearcey

    2017-12-01

    Full Text Available Spinal cord excitability, as assessed by modulation of Hoffmann (H- reflexes, is reduced with fatiguing isometric contractions. Furthermore, spinal cord excitability is reduced during non-fatiguing arm and leg cycling. Presynaptic inhibition of Ia terminals is believed to contribute to this suppression of spinal cord excitability. Electrical stimulation to cutaneous nerves reduces Ia presynaptic inhibition, which facilitates spinal cord excitability, and this facilitation is present during arm cycling. Although it has been suggested that reducing presynaptic inhibition may prolong fatiguing contractions, it is unknown whether sensory stimulation can alter the effects of fatiguing exercise on performance or spinal cord excitability. Thus, the aim of this experiment was to determine if sensory stimulation can interfere with fatigue-related suppression of spinal cord excitability, and alter fatigue rates during cycling sprints. Thirteen participants randomly performed three experimental sessions that included: unloaded cycling with sensory stimulation (CONTROL + STIM, sprints with sensory stimulation (SPRINT + STIM and sprints without stimulation (SPRINT. Seven participants also performed a fourth session (CONTROL, which consisted of unloaded cycling. During SPRINT and SPRINT + STIM, participants performed seven, 10 s cycling sprints interleaved with 3 min rest. For CONTROL and CONTROL + STIM, participants performed unloaded cycling for ~30 min. During SPRINT + STIM and CONTROL + STIM, participants received patterned sensory stimulation to nerves of the right foot. H-reflexes and M-waves of the right soleus were evoked by stimulation of the tibial nerve at multiple time points throughout exercise. Sensory stimulation facilitated soleus H-reflexes during unloaded cycling, whereas sprints suppressed soleus H-reflexes. While receiving sensory stimulation, there was less suppression of soleus H-reflexes and slowed reduction in average power output

  16. Spinal Cord Excitability and Sprint Performance Are Enhanced by Sensory Stimulation During Cycling.

    Science.gov (United States)

    Pearcey, Gregory E P; Noble, Steven A; Munro, Bridget; Zehr, E Paul

    2017-01-01

    Spinal cord excitability, as assessed by modulation of Hoffmann (H-) reflexes, is reduced with fatiguing isometric contractions. Furthermore, spinal cord excitability is reduced during non-fatiguing arm and leg cycling. Presynaptic inhibition of Ia terminals is believed to contribute to this suppression of spinal cord excitability. Electrical stimulation to cutaneous nerves reduces Ia presynaptic inhibition, which facilitates spinal cord excitability, and this facilitation is present during arm cycling. Although it has been suggested that reducing presynaptic inhibition may prolong fatiguing contractions, it is unknown whether sensory stimulation can alter the effects of fatiguing exercise on performance or spinal cord excitability. Thus, the aim of this experiment was to determine if sensory stimulation can interfere with fatigue-related suppression of spinal cord excitability, and alter fatigue rates during cycling sprints. Thirteen participants randomly performed three experimental sessions that included: unloaded cycling with sensory stimulation ( CONTROL + STIM ), sprints with sensory stimulation ( SPRINT + STIM ) and sprints without stimulation ( SPRINT ). Seven participants also performed a fourth session ( CONTROL ), which consisted of unloaded cycling. During SPRINT and SPRINT + STIM, participants performed seven, 10 s cycling sprints interleaved with 3 min rest. For CONTROL and CONTROL + STIM , participants performed unloaded cycling for ~30 min. During SPRINT + STIM and CONTROL + STIM , participants received patterned sensory stimulation to nerves of the right foot. H-reflexes and M-waves of the right soleus were evoked by stimulation of the tibial nerve at multiple time points throughout exercise. Sensory stimulation facilitated soleus H-reflexes during unloaded cycling, whereas sprints suppressed soleus H-reflexes. While receiving sensory stimulation, there was less suppression of soleus H-reflexes and slowed reduction in average power output, compared

  17. Junior High Career Planning: What Students Want

    Science.gov (United States)

    Bardick, Angela D.; Bernes, Kerry B.; Magnusson, Kris C.; Witko, Kim D.

    2004-01-01

    This research used "The Comprehensive Career Needs Survey" to assess the career counselling needs of 3,562 junior high students in Southern Alberta. This article examines junior high students' responses regarding their perceptions of (a) the relevance of career planning, (b) who they would approach for help with career planning, and (c)…

  18. Exploiting parallel R in the cloud with SPRINT.

    Science.gov (United States)

    Piotrowski, M; McGilvary, G A; Sloan, T M; Mewissen, M; Lloyd, A D; Forster, T; Mitchell, L; Ghazal, P; Hill, J

    2013-01-01

    Advances in DNA Microarray devices and next-generation massively parallel DNA sequencing platforms have led to an exponential growth in data availability but the arising opportunities require adequate computing resources. High Performance Computing (HPC) in the Cloud offers an affordable way of meeting this need. Bioconductor, a popular tool for high-throughput genomic data analysis, is distributed as add-on modules for the R statistical programming language but R has no native capabilities for exploiting multi-processor architectures. SPRINT is an R package that enables easy access to HPC for genomics researchers. This paper investigates: setting up and running SPRINT-enabled genomic analyses on Amazon's Elastic Compute Cloud (EC2), the advantages of submitting applications to EC2 from different parts of the world and, if resource underutilization can improve application performance. The SPRINT parallel implementations of correlation, permutation testing, partitioning around medoids and the multi-purpose papply have been benchmarked on data sets of various size on Amazon EC2. Jobs have been submitted from both the UK and Thailand to investigate monetary differences. It is possible to obtain good, scalable performance but the level of improvement is dependent upon the nature of the algorithm. Resource underutilization can further improve the time to result. End-user's location impacts on costs due to factors such as local taxation. Although not designed to satisfy HPC requirements, Amazon EC2 and cloud computing in general provides an interesting alternative and provides new possibilities for smaller organisations with limited funds.

  19. Lateral Squats Significantly Decrease Sprint Time in Collegiate Baseball Athletes

    Directory of Open Access Journals (Sweden)

    Jason B. White

    2016-03-01

    Full Text Available The purpose was to examine the effect of prior performance of dumbbell lateral squats (DBLS on an agility movement-into-a-sprint (AMS test. Twelve collegiate, resistance-trained, baseball athletes participated in three sessions separated by three days. Session One consisted of AMS baseline test, DBLS 5-RM test, and experimental protocol familiarization. Subjects were randomly assigned the protocol order for Sessions Two and Three, which consisted of warm up followed by 1-min sitting (no-DBLS or performing the DBLS for 1 × 5 repetitions @ 5RM for each leg. Four minutes of slow recovery walking preceded the AMS test, which consisted of leading off a base and waiting for a visual stimulus. In reaction to stimulus, subjects exerted maximal effort while moving to the right by either pivoting or drop stepping and sprinting for 10 yards (yd. In Session Three, subjects switched protocols (DBLS, no-DBLS. Foot contact time (FCT, stride frequency (SF, stride length (SL, and 10-yd sprint time were measured. There were no differences between conditions for FCT, SF, or SL. Differences existed between DBLS (1.85 ± 0.09 s and no-DBLS (1.89 ± 0.10 s for AMS (p = 0.03. Results from the current study support the use of DBLS for performance enhancement prior to performing the AMS test.

  20. Sprint vs. intermittent training in young female basketball players.

    Science.gov (United States)

    Attene, G; Pizzolato, F; Calcagno, G; Ibba, G; Pinna, M; Salernitano, G; Padulo, J

    2014-04-01

    This study aimed at comparing the effects of intermittent and repeated sprint ability training on physiological variables. Sixteen young female basketball players were randomly allocated to intermittent training (IT=8) or repeated sprint ability training (RST=8) groups. The following outcomes were measured at baseline and after 6 weeks of training: Yo-Yo intermittent recovery (Yo-Yo) and repeated sprint ability (RSA) tests. For all the variables investigated the effect of training type showed a different trend respect at current knowledge. In the RSA, best time (BT) was a significant main effect of training time (pre- vs. post-) (Ptraining type/time (P=0.03). The RST showed a decrease in BT of 3.1% (P=0.005) while the IT showed a decrease of 6.2% (Ptraining methods used in this study can be an effective training strategy for inducing anaerobic and basketball-specific training schedules. Besides, even when IT training is not done at very high speed, it can increase the maximum speed of the RSA.

  1. EL ENTRENAMIENTO DEL SPRINT CON MÉTODOS RESISTIDOS

    Directory of Open Access Journals (Sweden)

    Pedro E. Alcaraz Ramón

    2010-01-01

    Full Text Available Para la mejora del rendimiento en el sprint se utilizan distintos métodos de entrenamiento, entre los más populares se encuentran los métodos resistidos. Un método resistido, para el sprint, se caracteriza por utilizar sprints con una sobrecarga o resistencia añadida. Dependiendo de las características del dispositivo, tanto la magnitud como la dirección de la resistencia va a ser diferente. Así, existen distintos tipos de métodos resistidos, estos son: arrastres de trineos o ruedas, lastres de chalecos o cinturones, arrastres de paracaídas, carreras cuesta arriba, e incluso carreras sobre la arena de la playa. El principal objetivo al usar métodos resistidos es mejorar la fuerza específica de los deportistas sin producir una modificación significativa de la técnica del deportista. En el presente trabajo se revisan las características y efectos de los métodos resistidos tanto de forma aguda, como sus efectos a corto, medio y largo plazo.

  2. The Reliability and Validity of Fatigue Measures During Multiple-Sprint Work: An Issue Revisited

    OpenAIRE

    Glaister, Mark; Howatson, Glyn; Pattison, John R.; McInnes, Gill

    2008-01-01

    The ability to repeatedly produce a high-power output or sprint speed is a key fitness component of most field and court sports. The aim of this study was to evaluate the validity and reliability of eight different approaches to quantify this parameter in tests of multiple-sprint performance. Ten physically active men completed two trials of each of two multiple-sprint running protocols with contrasting recovery periods. Protocol 1 consisted of 12 × 30-m sprints repeated every 35 seconds; pro...

  3. Relative Age Effect in Physical Fitness Among Elementary and Junior High School Students.

    Science.gov (United States)

    Nakata, Hiroki; Akido, Miki; Naruse, Kumi; Fujiwara, Motoko

    2017-10-01

    The present study investigated characteristics of the relative age effect (RAE) among a general sample of Japanese elementary and junior high school students. Japan applies a unique annual age-grouping by birthdates between April 1 and March 31 of the following year for sport and education. Anthropometric and physical fitness data were obtained from 3,610 Japanese students, including height, weight, the 50-m sprint, standing long jump, grip strength, bent-leg sit-ups, sit and reach, side steps, 20-m shuttle run, and ball throw. We examined RAE-related differences in these data using a one-way analysis of variance by comparing students with birthdates in the first (April-September) versus second (October-March of the following year) semesters. We observed a significant RAE for boys aged 7 to 15 years on both anthropometric and fitness data, but a significant RAE for girls was only evident for physical fitness tests among elementary school and not junior high school students. Thus, a significant RAE in anthropometry and physical fitness was evident in a general sample of school children, and there were RAE gender differences among adolescents.

  4. Sprint interval and sprint continuous training increases circulating CD34+ cells and cardio-respiratory fitness in young healthy women.

    Directory of Open Access Journals (Sweden)

    Emma Harris

    Full Text Available The improvement of vascular health in the exercising limb can be attained by sprint interval training (SIT. However, the effects on systemic vascular function and on circulating angiogenic cells (CACs which may contribute to endothelial repair have not been investigated. Additionally, a comparison between SIT and sprint continuous training (SCT which is less time committing has not been made.12 women (22±2 yrs completed 12 sessions of either SIT (n = 6 or work-matched SCT (n = 6 on 3 days/week. Pre and post-training assessments included brachial artery endothelial function and peripheral blood analysis for CAC number (CD34+/CD34+CD45dim. CAC function was measured by migration and adhesion assays. Cardio-respiratory fitness, carotid arterial stiffness and carotid-radial and brachial-foot pulse wave velocity (PWV were also evaluated.CD34+ CACs increased following training in both groups but CD34+CD45dim did not (Pre CD34+: 40±21/105 leukocytes, Post CD34+: 56±24/105 leukocytes, main time effect p0.05.SCT involving little time commitment is comparable to SIT in increasing CD34+ cell number and [Formula: see text]. An increased mobilisation of CD34+ CACs suggests that sprint training may be an effective method to enhance vascular repair.

  5. Game movement demands and physical profiles of junior, senior and elite male and female rugby sevens players.

    Science.gov (United States)

    Clarke, Anthea C; Anson, Judith M; Pyne, David B

    2017-04-01

    To inform recruitment, selection, training and testing of male and female rugby sevens players game running movement patterns and physical characteristics were quantified across junior, senior, and elite playing levels. Anthropometric and physical testing (40 m sprint, vertical jump, Yo-Yo IR1) occurred prior to players' national championships or international tournaments (n = 110 players), while game movements were obtained via GPS (n = 499 game files). The game movements of male players were similar across playing levels except for number of impacts >10 g which were 2 to 4-fold higher in elite (25.0 ± 11.2 impacts · game - 1 ; mean ± SD), than junior (6.3 ± 3.5) and senior (11.8 ± 6.6) players. In men, there were fewer substantial correlations between on- and off-field measures which may reflect similar physical attributes across playing levels, and that other (strength, technical or tactical) factors may better differentiate these players. In females, elite players had more favourable on- and off-field performance measures than juniors and seniors, with moderate to strong correlations between on- and off-field variables. Female players should benefit from additional fitness training, while male players need to balance fitness with other technical and tactical factors.

  6. CARIES PREVENTION AMONG JUNIOR SCHOOLCHILDREN

    Directory of Open Access Journals (Sweden)

    S.К. Matelo

    2011-01-01

    Full Text Available Biennial program of controlled tooth brushing performed econdary school among junior schoolchildren from Minsk secondary school № 166 proved to be highly effective. Decrease in caries increment has been shown on the average up to 50%. No credible differences between remineralising defluorinated toothpastes or pastes enriched with aminofluoride (F = 500 ppm and sodium fluoride  (F = 1000 ppm efficacy were found in this study. Credibility of the results was determined by comparison with similar study conducted on a bigger population of children. Though anti-caries effect of the same tooth-pastes in a bigger-scale study was lower — within 30%. Such difference can be explained by a different level of motivation and discipline of participants.Key words: schoolchildren, dental caries prevention, toothpastes. (Voprosy sovremennoi pediatrii — Current Pediatrics. — 2011; 10 (6: 48–51

  7. Comparison of step-by-step kinematics in repeated 30m sprints in female soccer players.

    Science.gov (United States)

    van den Tillaar, Roland

    2018-01-04

    The aim of this study was to compare kinematics in repeated 30m sprints in female soccer players. Seventeen subjects performed seven 30m sprints every 30s in one session. Kinematics were measured with an infrared contact mat and laser gun, and running times with an electronic timing device. The main findings were that sprint times increased in the repeated sprint ability test. The main changes in kinematics during the repeated sprint ability test were increased contact time and decreased step frequency, while no change in step length was observed. The step velocity increased in almost each step until the 14, which occurred around 22m. After this, the velocity was stable until the last step, when it decreased. This increase in step velocity was mainly caused by the increased step length and decreased contact times. It was concluded that the fatigue induced in repeated 30m sprints in female soccer players resulted in decreased step frequency and increased contact time. Employing this approach in combination with a laser gun and infrared mat for 30m makes it very easy to analyse running kinematics in repeated sprints in training. This extra information gives the athlete, coach and sports scientist the opportunity to give more detailed feedback and help to target these changes in kinematics better to enhance repeated sprint performance.

  8. Effect of fatigue on force production and force application technique during repeated sprints.

    Science.gov (United States)

    Morin, Jean-Benoit; Samozino, Pierre; Edouard, Pascal; Tomazin, Katja

    2011-10-13

    We investigated the changes in the technical ability of force application/orientation against the ground vs. the physical capability of total force production after a multiple-set repeated sprints series. Twelve male physical education students familiar with sprint running performed four sets of five 6-s sprints (24s of passive rest between sprints, 3min between sets). Sprints were performed from a standing start on an instrumented treadmill, allowing the computation of vertical (F(V)), net horizontal (F(H)) and total (F(Tot)) ground reaction forces for each step. Furthermore, the ratio of forces was calculated as RF=F(H)F(Tot)(-1), and the index of force application technique (D(RF)) representing the decrement in RF with increase in speed was computed as the slope of the linear RF-speed relationship. Changes between pre- (first two sprints) and post-fatigue (last two sprints) were tested using paired t-tests. Performance decreased significantly (e.g. top speed decreased by 15.7±5.4%; Pmultiple-set repeated sprint series, both the total force production capability and the technical ability to apply force effectively against the ground are altered, the latter to a larger extent than the former. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Muscle Damage and Metabolic Responses to Repeated-Sprint Running With and Without Deceleration.

    Science.gov (United States)

    Minahan, Clare L; Poke, Daniel P; Morrison, Jaime; Bellinger, Phillip M

    2018-04-04

    Minahan, CL, Poke, DP, Morrison, J, and Bellinger, PM. Muscle damage and metabolic responses to repeated-sprint running with and without deceleration. J Strength Cond Res XX(X): 000-000, 2017-This study aimed to determine whether repeated-sprint running with deceleration aggravates markers of muscle damage or delays the recovery of performance compared with repeated-sprint running without deceleration. Fourteen male team-sport athletes performed 2 randomly ordered testing sessions on a nonmotorized treadmill with one session requiring participants to decelerate (TMd) within 4 seconds before stopping or immediately step to the side of the treadmill belt at the completion of each sprint (TMa). Peak and mean velocities, speed decrement, blood lactate concentrations, and oxygen uptake were monitored during the repeated-sprint running protocols. Countermovement vertical jump (CMJ) performance, perceived muscle soreness, sit-and-reach flexibility, plasma creatine kinase (CK), lactate dehydrogenase (LDH), and myoglobin (Mb) concentrations were quantified immediately before and after and 45 minutes, 24 and 48 hours after repeated-sprint running protocols. Although muscle damage was indicated by increases in CK, LDH, and Mb (p ≤ 0.05) in both groups, there was no significant effect of condition (TMa vs. TMd) on any of the measured performance or physiological variables (p > 0.05). The present study indicated that the removal of deceleration from repeated-sprint running on a nonmotorized treadmill has no effect on metabolism or performance during or after repeated-sprint running or markers of muscle damage.

  10. Within-cycle characteristics of the wheelchair push in sprinting on a wheelchair ergometer

    NARCIS (Netherlands)

    Veeger, DirkJan (H. E. J.); van der Woude, L H; Rozendal, R H

    To investigate power output and torque production in wheelchair sprinting, six able-bodied subjects performed nine 20-s sprint tests on a stationary wheelchair ergometer (load 0-8 kg). Ergometer data were analyzed and combined with kinematic data and surface electromyography. Of all power and torque

  11. Reduction in plasma leucine after sprint exercise is greater in males than in females

    DEFF Research Database (Denmark)

    Esbjörnsson, M; Rooyackers, O; Norman, B

    2012-01-01

    There is a pronounced gender difference in the accumulation of plasma ammonia after sprint exercise. Ammonia is a key intermediate in amino acid metabolism, which implies that gender-related differences in plasma and muscle amino acid concentrations after sprint exercise exist. To study this, three...

  12. Sprint's Social Media Ninja Program: A Model for Teaching Consumer Relations

    Science.gov (United States)

    Gilliland, Rebecca A.

    2017-01-01

    This study reviews the application of a new training model, Sprint's Social Media Ninja program, an innovative approach to using new media to initiate change. Sprint recognized change management must occur from employee ambassadors to relevant audiences including consumers and other employees. By teaching volunteer employees the strategic message…

  13. The Effects of Psoas Major and Lumbar Lordosis on Hip Flexion and Sprint Performance

    Science.gov (United States)

    Copaver, Karine; Hertogh, Claude; Hue, Olivier

    2012-01-01

    In this study, we analyzed the correlations between hip flexion power, sprint performance, lumbar lordosis (LL) and the cross-sectional area (CSA) of the psoas muscle (PM). Ten young adults performed two sprint tests and isokinetic tests to determine hip flexion power. Magnetic resonance imaging was used to determine LL and PM CSA. There were…

  14. Repeated sprint ability in young basketball players: one vs. two changes of direction (Part 2).

    Science.gov (United States)

    Attene, Giuseppe; Laffaye, Guillaume; Chaouachi, Anis; Pizzolato, Fabio; Migliaccio, Gian Mario; Padulo, Johnny

    2015-01-01

    The aim of this study was to compare the training effects based on repeated sprint ability (RSA) (with one change of direction) with an intensive repeated sprint ability (IRSA) (with two changes of direction) on jump performance and aerobic fitness. Eighteen male basketball players were assigned to repeated sprint ability and intensive repeated sprint ability training groups (RSAG and IRSAG). RSA, IRSA, squat jump (SJ), countermovement jump (CMJ) and Yo-Yo intermittent recovery level 1 test were assessed before and after four training weeks. The RSA and IRSA trainings consisted of three sets of six sprints (first two weeks) and eight sprints (second two weeks) with 4-min sets recovery and 20-s of sprints recovery. Four weeks of training led to an overall improvement in most of the measures of RSA, but little evidence of any differences between the two training modes. Jump performance was enhanced: CMJ of 7.5% (P training with one/two changes of direction promotes improvements in both RSA and IRSA respectively but the better increase on jump performance shown a few changes on sprint and endurance performances.

  15. An Analysis of Collaborative Problem-Solving Mechanisms in Sponsored Projects: Applying the 5-Day Sprint Model

    Science.gov (United States)

    Raubenolt, Amy

    2016-01-01

    In May 2016, the office of Finance and Sponsored Projects at The Research Institute at Nationwide Children's Hospital conducted a 5-day design sprint session to re-evaluate and redesign a flawed final reporting process within the department. The department sprint was modeled after the design sprint sessions that occur routinely in software…

  16. Neck-cooling improves repeated sprint performance in the heat

    Directory of Open Access Journals (Sweden)

    Caroline eSunderland

    2015-11-01

    Full Text Available The present study evaluated the effect of neck-cooling during exercise on repeated sprint ability in a hot environment. Seven team-sport playing males completed two experimental trials involving repeated sprint exercise (5 x 6 s before and after two 45 min bouts of a football specific intermittent treadmill protocol in the heat (33.0  0.2 ºC; 53 ± 2% relative humidity. Participants wore a neck-cooling collar in one of the trials (CC. Mean power output and peak power output declined over time in both trials but were higher in CC (540 ± 99 v 507 ± 122W, d = 0.32; 719 ± 158 v 680 ± 182 W, d = 0.24 respectively. The improved power output was particularly pronounced (d = 0.51 – 0.88 after the 2nd 45 min bout but the CC had no effect on % fatigue. The collar lowered neck temperature and the thermal sensation of the neck (P 0.05. There were no trial differences but interaction effects were demonstrated for prolactin concentration and rating of perceived exertion (RPE. Prolactin concentration was initially higher in the collar cold trial and then was lower from 45 minutes onwards (interaction trial x time P=0.04. RPE was lower during the football intermittent treadmill protocol in the collar cold trial (interaction trial x time P = 0.01. Neck-cooling during exercise improves repeated sprint performance in a hot environment without altering physiological or neuroendocrinological responses. RPE is reduced and may partially explain the performance improvement.

  17. Dynamic factors and electromyographic activity in a sprint start

    Directory of Open Access Journals (Sweden)

    M Čoh

    2009-07-01

    Full Text Available The aim of the study was to establish the major dynamic parameters as well as the EMG activation of muscles in a sprint start as the first derivative of sprint velocity. The subject of the analysis was block velocity, the production of force in the front and rear starting blocks, the block acceleration in the first two steps and the electromyographic activity (EMG of the following muscles: the erector spinae muscle, gluteus maximus muscle, rectus femoris muscle, vastus medialis muscle, vastus lateralis muscle, biceps femoris muscle and gastrocnemius–medialis muscle. One international-class female sprinter participated in the experiment. She performed eight starts in constant laboratory conditions. The 3-D kinematic analysis was made using a system of nine Smart-e 600 cameras operating at a frame rate of 60 Hz. Dynamic parameters were established by means of two separate force platforms to which the starting blocks were fixed. A 16-channel electromyograph was used to analyse electromyographic activity (EMG. It was established that the block velocity depended on the absolute force produced in the front and rear starting blocks and that it was 2.84±0.21 m.s-1. The maximal force on the rear and front blocks was 628±34 N and 1023±30 N, respectively. In view of the total impulse (210±11 Ns the force production/time ratio in the rear and front blocks was 34%:66%. The erector spinae muscle, vastus lateralis muscle and gastrocnemius–medialis muscle generate the efficiency of the start. The block acceleration in the first two steps primarily depends on the activation of the gluteus maximus muscle, rectus femoris muscle, biceps femoris muscle and gastrocnemius–medialis muscle. A sprint start is a complex motor stereotype requiring a high degree of integration of the processes of central movement regulation and an optimal level of biomotor abilities.

  18. MONITORING SWIMMING SPRINT PERFORMANCE DURING A TRAINING CYCLE

    Directory of Open Access Journals (Sweden)

    Daniel A. Marinho

    2009-12-01

    Full Text Available The preparation for a major competition is an important concern of coaches and athletes. Therefore, the aim of this study was to evaluate the evolution in sprint performance during a training macro cycle in age-group swimmers of both genders. The sample comprised twenty four age-group swimmers (12.0 ± 0.72 years old, 41.43 ± 6.88 kg, 1.51 ± 0.09 m. The evaluations occurred during nine weeks of swimming training in the first macro cycle. During this period the subjects performed 54 training units (6 units per week. In all weeks, the performance in two trials of a 25 m front crawl all out test, with 15 min of rest, was recorded. Only the bestperformance was used to assess the effects of training. Comparisons between the first week and the following weeks were conducted using pair-sample t-test. The significance level was set at 5%. The sprint performance did not change during the first 6 weeks of preparation. In the last three weeks the performance in the 25 m front crawl test was improved when compared with the first week, although the major changes occurred at the last week of preparation.It seems that in age-group swimmers seven weeks of specific swimming training enables improving swimmer’s sprint performance, although some differences exists between male and female swimmers. Thesedata could be used by coaches to program the training season and the evolution of the load components.

  19. Development of repeated sprint ability in talented youth basketball players.

    Science.gov (United States)

    te Wierike, Sanne C M; de Jong, Mark C; Tromp, Eveline J Y; Vuijk, Pieter J; Lemmink, Koen A P M; Malina, Robert M; Elferink-Gemser, Marije T; Visscher, Chris

    2014-04-01

    Factors affecting repeated sprint ability (RSA) were evaluated in a mixed-longitudinal sample of 48 elite basketball players 14-19 years of age (16.1 ± 1.7 years). Players were observed on 6 occasions during the 2008-09 and 2009-10 seasons. Three following basketball-specific field tests were administered on each occasion: the shuttle sprint test for RSA, the vertical jump for lower body explosive strength (power), and the interval shuttle run test for interval endurance capacity. Height and weight were measured; body composition was estimated (percent fat, lean body mass). Multilevel modeling of RSA development curve was used with 32 players (16.0 ± 1.7 years) who had 2 or more observations. The 16 players (16.1 ± 1.8 years) measured on only 1 occasion were used as a control group to evaluate the appropriateness of the model. Age, lower body explosive strength, and interval endurance capacity significantly contributed to RSA (p ≤ 0.05). Repeated sprint ability improved with age from 14 to 17 years (p ≤ 0.05) and reached a plateau at 17-19 years. Predicted RSA did not significantly differ from measured RSA in the control group (p ≥ 0.05). The results suggest a potentially important role for the training of lower body explosive strength and interval endurance capacity in the development of RSA among youth basketball players. Age-specific reference values for RSA of youth players may assist basketball coaches in setting appropriate goals for individual players.

  20. The force, power and energy of the 100 meter sprint

    OpenAIRE

    Helene, O.; Yamashita, M. T.

    2009-01-01

    At the 2008 Summer Olympics in Beijing, Usain Bolt broke the world record for the 100 m sprint. Just one year later, at the 2009 World Championships in Athletics in Berlin he broke it again. A few months after Beijing, Eriksen [Am. J. Phys. 77, 224-228 (2009)] studied Bolt's performance and predicted that Bolt could have run about one-tenth of a second faster, which was confirmed in Berlin. In this paper we extend the analysis of Eriksen to model Bolt's velocity time dependence for the Beijin...

  1. Teacher Pupil Contact in Junior Classrooms

    Science.gov (United States)

    Boydell, D.

    1974-01-01

    The purpose of the exploratory study reported here was to examine the nature of teacher-pupil contact in informal junior classrooms in terms of the teacher's method of talking to children and the teacher's conversational approach. (Author/RK)

  2. The Community Junior College: An Annotated Bibliography.

    Science.gov (United States)

    Rarig, Emory W., Jr., Ed.

    This annotated bibliography on the junior college is arranged by topic: research tools, history, functions and purposes, organization and administration, students, programs, personnel, facilities, and research. It covers publications through the fall of 1965 and has an author index. (HH)

  3. Junior High School Pupils' Perceptions of Air

    African Journals Online (AJOL)

    cce

    Abstract. The study examined Junior High School (JHS) pupils' ideas of the concept air. The ... Stavy (1991) reported that students in his physics class had ... Research studies found that even after having been taught the particulate theory and.

  4. Repeated-Sprint Sequences During Female Soccer Matches Using Fixed and Individual Speed Thresholds.

    Science.gov (United States)

    Nakamura, Fábio Y; Pereira, Lucas A; Loturco, Irineu; Rosseti, Marcelo; Moura, Felipe A; Bradley, Paul S

    2017-07-01

    Nakamura, FY, Pereira, LA, Loturco, I, Rosseti, M, Moura, FA, and Bradley, PS. Repeated-sprint sequences during female soccer matches using fixed and individual speed thresholds. J Strength Cond Res 31(7): 1802-1810, 2017-The main objective of this study was to characterize the occurrence of single sprint and repeated-sprint sequences (RSS) during elite female soccer matches, using fixed (20 km·h) and individually based speed thresholds (>90% of the mean speed from a 20-m sprint test). Eleven elite female soccer players from the same team participated in the study. All players performed a 20-m linear sprint test, and were assessed in up to 10 official matches using Global Positioning System technology. Magnitude-based inferences were used to test for meaningful differences. Results revealed that irrespective of adopting fixed or individual speed thresholds, female players produced only a few RSS during matches (2.3 ± 2.4 sequences using the fixed threshold and 3.3 ± 3.0 sequences using the individually based threshold), with most sequences composing of just 2 sprints. Additionally, central defenders performed fewer sprints (10.2 ± 4.1) than other positions (fullbacks: 28.1 ± 5.5; midfielders: 21.9 ± 10.5; forwards: 31.9 ± 11.1; with the differences being likely to almost certainly associated with effect sizes ranging from 1.65 to 2.72), and sprinting ability declined in the second half. The data do not support the notion that RSS occurs frequently during soccer matches in female players, irrespective of using fixed or individual speed thresholds to define sprint occurrence. However, repeated-sprint ability development cannot be ruled out from soccer training programs because of its association with match-related performance.

  5. Effects of supplementation with acai ( Euterpe oleracea Mart. berry-based juice blend on the blood antioxidant defence capacity and lipid profile in junior hurdlers. A pilot study

    Directory of Open Access Journals (Sweden)

    E Sadowska-Krępa

    2015-05-01

    Full Text Available The purpose of this pilot study was to examine whether regular consumption of an acai berry-based juice blend would affect sprint performance and improve blood antioxidant status and lipid profile in junior athletes. Seven junior hurdlers (17.5±1.2 years taking part in a pre-season conditioning camp were supplemented once a day, for six weeks, with 100 ml of the juice blend. At the start and the end of the camp the athletes performed a 300-m sprint running test on an outdoor track. Blood samples were taken before and immediately after the test and after 1 h of recovery. Blood antioxidant status was evaluated based on activities of antioxidant enzymes (superoxide dismutase [SOD], catalase [CAT], glutathione peroxidase [GSH-Px], glutathione reductase [GR], concentrations of non-enzymatic antioxidants (reduced glutathione [GSH], uric acid, total plasma polyphenols, ferric reducing ability of plasma (FRAP, thiobarbituric acid reactive substances (TBARS and activities of creatine kinase (CK and lactate dehydrogenase (LDH as muscle damage markers. In order to evaluate potential health benefits of the acai berry, the post-treatment changes in lipid profile parameters (triglycerides, cholesterol and its fractions were analysed. Six weeks’ consumption of acai berry-based juice blend had no effect on sprint performance, but it led to a marked increase in the total antioxidant capacity of plasma, attenuation of the exercise-induced muscle damage, and a substantial improvement of serum lipid profile. These findings strongly support the view of the health benefits of supplementation with the acai berry-based juice blend, mainly attributed to its high total polyphenol content and the related high in vivo antioxidant and hypocholesterolaemic activities of this supplement.

  6. The Effects of 3-Month Skill-Based and Plyometric Conditioning on Fitness Parameters in Junior Female Volleyball Players.

    Science.gov (United States)

    Idrizovic, Kemal; Gjinovci, Bahri; Sekulic, Damir; Uljevic, Ognjen; João, Paulo Vicente; Spasic, Miodrag; Sattler, Tine

    2018-02-24

    This study compared the effects of skill-based and plyometric conditioning (both performed in addition to regular volleyball training twice a week for 12 wk) on fitness parameters in female junior volleyball players. The participants [n = 47; age: 16.6 (0.6) y; mass: 59.4 (8.1) kg; height: 175.1 (3.0) cm] were randomized into a plyometric (n = 13), a skill-based (n = 17), and a control (n = 17) groups. The variables included body height, body mass, calf girth, calf skinfold, corrected calf girth, countermovement jump, 20-m-sprint, medicine ball toss, and sit-and-reach test. Two-way analysis of variance (time × group) effects for time were significant (P plyometric group, and sit-and-reach (η 2  = .35; large ES), with greater gains in plyometric and skill-based groups. The magnitude-based inference indicated positive changes in 1) medicine ball toss and countermovement jump for all groups; 2) sit-and-reach for the plyometric and skill-based groups; and 3) 20-m sprint, calf girth, calf skinfold, and corrected calf girth for plyometric group only. Selected variables can be improved by adding 2 plyometric training sessions throughout the period of 12 weeks. Additional skill-based conditioning did not contribute to improvement in the studied variables compared with regular volleyball training.

  7. Predicting higher selection in elite junior Australian Rules football: The influence of physical performance and anthropometric attributes.

    Science.gov (United States)

    Robertson, Sam; Woods, Carl; Gastin, Paul

    2015-09-01

    To develop a physiological performance and anthropometric attribute model to predict Australian Football League draft selection. Cross-sectional observational. Data was obtained (n=4902) from three Under-18 Australian football competitions between 2010 and 2013. Players were allocated into one of the three groups, based on their highest level of selection in their final year of junior football (Australian Football League Drafted, n=292; National Championship, n=293; State-level club, n=4317). Physiological performance (vertical jumps, agility, speed and running endurance) and anthropometric (body mass and height) data were obtained. Hedge's effect sizes were calculated to assess the influence of selection-level and competition on these physical attributes, with logistic regression models constructed to discriminate Australian Football League Drafted and National Championship players. Rule induction analysis was undertaken to determine a set of rules for discriminating selection-level. Effect size comparisons revealed a range of small to moderate differences between State-level club players and both other groups for all attributes, with trivial to small differences between Australian Football League Drafted and National Championship players noted. Logistic regression models showed multistage fitness test, height and 20 m sprint time as the most important attributes in predicting Draft success. Rule induction analysis showed that players displaying multistage fitness test scores of >14.01 and/or 20 m sprint times of football players being recruited to the highest level of the sport. Copyright © 2014 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  8. Effects of Sprint Interval Training With Active Recovery vs. Endurance Training on Aerobic and Anaerobic Power, Muscular Strength, and Sprint Ability.

    Science.gov (United States)

    Sökmen, Bülent; Witchey, Ronald L; Adams, Gene M; Beam, William C

    2018-03-01

    Sökmen, B, Witchey, RL, Adams, GM, and Beam, WC. Effects of sprint interval training with active recovery vs. endurance training on aerobic and anaerobic power, muscular strength, and sprint ability. J Strength Cond Res 32(3): 624-631, 2018-This study compared sprint interval training with active recovery (SITAR) to moderate-intensity endurance training (ET) in aerobic and anaerobic power, muscular strength, and sprint time results. Forty-two recreationally active adults were randomly assigned to a SITAR or ET group. Both groups trained 3× per week for 10 weeks at 75% of V[Combining Dot Above]O2max for 30 minutes weeks 1-4, with duration increasing to 35 minutes weeks 5-7 and 40 minutes weeks 8-10. While ET ran on a 400-m track without rest for the full training session, SITAR sprinted until the 200-m mark and recovered with fast walking or light jogging the second 200 m to the finish line in 3× original sprint time. Maximal oxygen consumption (V[Combining Dot Above]O2max), anaerobic treadmill run to exhaustion at 12.5 km·h at 20% incline, isokinetic leg extension and flexion strength at 60 and 300°·s, and 50 m sprint time were determined before and after training. Results showed a significant improvement (p ≤ 0.05) in absolute and relative V[Combining Dot Above]O2max, anaerobic treadmill run, and sprint time in both groups. Only SITAR showed significant improvements in isokinetic leg extension and flexion at 300°·s and decreases in body mass (p ≤ 0.05). SITAR also showed significantly greater improvement (p ≤ 0.05) over ET in anaerobic treadmill run and 50 m sprint time. These data suggest that SITAR is a time-efficient strategy to induce rapid adaptations in V[Combining Dot Above]O2max comparable to ET with added improvements in anaerobic power, isokinetic strength, and sprint time not observed with ET.

  9. The reliability and validity of fatigue measures during multiple-sprint work: an issue revisited.

    Science.gov (United States)

    Glaister, Mark; Howatson, Glyn; Pattison, John R; McInnes, Gill

    2008-09-01

    The ability to repeatedly produce a high-power output or sprint speed is a key fitness component of most field and court sports. The aim of this study was to evaluate the validity and reliability of eight different approaches to quantify this parameter in tests of multiple-sprint performance. Ten physically active men completed two trials of each of two multiple-sprint running protocols with contrasting recovery periods. Protocol 1 consisted of 12 x 30-m sprints repeated every 35 seconds; protocol 2 consisted of 12 x 30-m sprints repeated every 65 seconds. All testing was performed in an indoor sports facility, and sprint times were recorded using twin-beam photocells. All but one of the formulae showed good construct validity, as evidenced by similar within-protocol fatigue scores. However, the assumptions on which many of the formulae were based, combined with poor or inconsistent test-retest reliability (coefficient of variation range: 0.8-145.7%; intraclass correlation coefficient range: 0.09-0.75), suggested many problems regarding logical validity. In line with previous research, the results support the percentage decrement calculation as the most valid and reliable method of quantifying fatigue in tests of multiple-sprint performance.

  10. The effects of precompetition massage on the kinematic parameters of 20-m sprint performance.

    Science.gov (United States)

    Fletcher, Iain M

    2010-05-01

    The purpose of this study was to investigate what effect precompetition massage has on short-term sprint performance. Twenty male collegiate games players, with a minimum training/playing background of 3 sessions per week, were assigned to a randomized, counter-balanced, repeated-measures designed experiment used to analyze 20-m sprints performance. Three discrete warm-up modalities, consisting of precompetition massage, a traditional warm-up, and a precompetition massage combined with a traditional warm-up were used. Massage consisted of fast, superficial techniques designed to stimulate the main muscle groups associated with sprint running. Twenty-meter sprint performance and core temperature were assessed post warm-up interventions. Kinematic differences between sprints were assessed through a 2-dimensional computerized motion analysis system (alpha level p velocity were found to be significantly greater in the warm-up and massage combined with warm-up modalities when compared to massage alone. No significant differences were demonstrated in any measures when the warm-up and massage and warm-up combined conditions were compared. Massage as a preperformance preparation strategy seems to decrease 20-m sprint performance when compared to a traditional warm-up, although its combination with a normal active warm-up seems to have no greater benefit then active warm-up alone. Therefore, massage use prior to competition is questionable because it appears to have no effective role in improving sprint performance.

  11. Does Vibration Warm-up Enhance Kinetic and Temporal Sprint Parameters?

    Science.gov (United States)

    Cochrane, D J; Cronin, M J; Fink, P W

    2015-08-01

    The aim of this study was to investigate the efficacy of vibration warm-up to enhance sprint performance. 12 males involved in representative team sports performed 4 warm-up conditions in a randomised order performed at least 24 h apart; VbX warm-up (VbX-WU); Neural activation warm-up (Neu-WU); Dynamic warm-up (Dyn-WU) and Control (No VbX). Participants completed 5 m sprint at 30 s, 2:30 min and 5 min post warm-up where sprint time, kinetics, and temporal components were recorded. There was no significant (p>0.05) main effect or interaction effect between the split sprint times of 1 m, 2.5 m, and 5 m. There was a condition effect where vertical mean force was significantly higher (p0.05) main and interaction effects in sprint kinetic and temporal parameters existed. Overall, all 4 warm-up conditions produced comparable results for sprint performance, and there was no detrimental effect on short-duration sprint performance using VbX-WU. Therefore, VbX could be useful for adding variety to the training warm-up or be included into the main warm-up routine as a supplementary modality. © Georg Thieme Verlag KG Stuttgart · New York.

  12. Correlation between explosive strength, aerobic power and repeated sprint ability in elite basketball players.

    Science.gov (United States)

    Stojanovic, M D; Ostojic, S M; Calleja-González, J; Milosevic, Z; Mikic, M

    2012-08-01

    The aim of this study was to examine the relationship between explosive strength and aerobic power with basketball-specific repeated sprint ability in elite male basketball players. Twenty-four elite basketball players (age 22.2±3.4 years, height 197.1±6.2 cm, weight 95.7±8.8 kg; training experience 11.0±3.1 years; mean±SD), participated in the study. Subjects performed countermovement jump (CMJ) test and incremental pseudo-ramp test protocol with measured CMJ height and VO2max, respectively. Specific repeated sprint ability (RSA) test was conducted, with total sprinting time (summation of 10 sprint times - RSAtot) and sprint decrement (fatigue index - RSAFI) calculated. Significant decrements in sprint performance from the eight 30-m sprint (Pbasketball players. It seems that coaches and strength and conditioning professionals should devote additional time for explosive strength development in elite basketball players during preparatory period to enhance RSA performance.

  13. Effect of sprint training on resting serum irisin concentration - Sprint training once daily vs. twice every other day.

    Science.gov (United States)

    Tsuchiya, Yoshifumi; Ijichi, Toshiaki; Goto, Kazushige

    2016-04-01

    Exercise twice every other day has been shown to lead to increasing peroxisome proliferator receptor γ coactivator-1α (PGC-1α) expression (up-stream factor of irisin) via lowered muscle glycogen level during second of exercise compared with exercise once daily. This study determined the influence of 4weeks of sprint training (training once daily vs. twice every other day) on the serum irisin concentration. Twenty healthy males (20.9±1.3years) were assigned randomly to either the SINGLE or REPEATED group (n=10 per group). The subjects in the SINGLE group participated in a sprint training session once daily (5days per week), whereas those in the REPEATED group performed two consecutive training sessions on the same day with a 1-h rest between sessions (2-3days per week). Both groups completed 20 training sessions over 4weeks. Each training session consisted of three consecutive 30-s maximal pedaling exercises with a 10-min rest between sets. Blood samples were collected before and after training period (48h after completing the last training session). The serum irisin concentration decreased significantly after training in each group (SINGLE, 338.5±77.8 to 207.6±64.6ng/mL; REPEATED, 329.5±83.9 to 234.2±72.8ng/mL, pevery other day). Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Sprinting performance on the Woodway Curve 3.0 is related to muscle architecture.

    Science.gov (United States)

    Mangine, Gerald T; Fukuda, David H; Townsend, Jeremy R; Wells, Adam J; Gonzalez, Adam M; Jajtner, Adam R; Bohner, Jonathan D; LaMonica, Michael; Hoffman, Jay R; Fragala, Maren S; Stout, Jeffrey R

    2015-01-01

    To determine if unilateral measures of muscle architecture in the rectus femoris (RF) and vastus lateralis (VL) were related to (and predictive of) sprinting speed and unilateral (and bilateral) force (FRC) and power (POW) during a 30 s maximal sprint on the Woodway Curve 3.0 non-motorized treadmill. Twenty-eight healthy, physically active men (n = 14) and women (n = 14) (age = 22.9 ± 2.4 years; body mass = 77.1 ± 16.2 kg; height = 171.6 ± 11.2 cm; body-fa t = 19.4 ± 8.1%) completed one familiarization and one 30-s maximal sprint on the TM to obtain maximal sprinting speed, POW and FRC. Muscle thickness (MT), cross-sectional area (CSA) and echo intensity (ECHO) of the RF and VL in the dominant (DOM; determined by unilateral sprinting power) and non-dominant (ND) legs were measured via ultrasound. Pearson correlations indicated several significant (p architecture. Stepwise regression indicated that POW(DOM) was predictive of ipsilateral RF (MT and CSA) and VL (CSA and ECHO), while POW(ND) was predictive of ipsilateral RF (MT and CSA) and VL (CSA); sprinting power/force asymmetry was not predictive of architecture asymmetry. Sprinting time was best predicted by peak power and peak force, though muscle quality (ECHO) and the bilateral percent difference in VL (CSA) were strong architectural predictors. Muscle architecture is related to (and predictive of) TM sprinting performance, while unilateral POW is predictive of ipsilateral architecture. However, the extent to which architecture and other factors (i.e. neuromuscular control and sprinting technique) affect TM performance remains unknown.

  15. Effects of combined creatine and sodium bicarbonate supplementation on repeated sprint performance in trained men.

    Science.gov (United States)

    Barber, James J; McDermott, Ann Y; McGaughey, Karen J; Olmstead, Jennifer D; Hagobian, Todd A

    2013-01-01

    Creatine and sodium bicarbonate supplementation independently increase exercise performance, but it remains unclear whether combining these 2 supplements is more beneficial on exercise performance. The purpose of this study was to evaluate the impact of combining creatine monohydrate and sodium bicarbonate supplementation on exercise performance. Thirteen healthy, trained men (21.1 ± 0.6 years, 23.5 ± 0.5 kg·m(-2), 66.7 ± 5.7 ml·(kg·m)(-1) completed 3 conditions in a double-blinded, crossover fashion: (a) Placebo (Pl; 20 g maltodextrin + 0.5 g·kg(-1) maltodextrin), (b) Creatine (Cr; 20 g + 0.5 g·kg(-1) maltodextrin), and (c) Creatine plus sodium bicarbonate (Cr + Sb; 20 g + 0.5 g·kg(-1) sodium bicarbonate). Each condition consisted of supplementation for 2 days followed by a 3-week washout. Peak power, mean power, relative peak power, and bicarbonate concentrations were assessed during six 10-second repeated Wingate sprint tests on a cycle ergometer with a 60-second rest period between each sprint. Compared with Pl, relative peak power was significantly higher in Cr (4%) and Cr + Sb (7%). Relative peak power was significantly lower in sprints 4-6, compared with that in sprint 1, in both Pl and Cr. However, in Cr + Sb, sprint 6 was the only sprint significantly lower compared with sprint 1. Pre-Wingate bicarbonate concentrations were significantly higher in Cr + Sb (10%), compared with in Pl and Cr, and mean concentrations remained higher after sprint 6, although not significantly. Combining creatine and sodium bicarbonate supplementation increased peak and mean power and had the greatest attenuation of decline in relative peak power over the 6 repeated sprints. These data suggest that combining these 2 supplements may be advantageous for athletes participating in high-intensity, intermittent exercise.

  16. Significant molecular and systemic adaptations after repeated sprint training in hypoxia.

    Directory of Open Access Journals (Sweden)

    Raphael Faiss

    Full Text Available While intermittent hypoxic training (IHT has been reported to evoke cellular responses via hypoxia inducible factors (HIFs but without substantial performance benefits in endurance athletes, we hypothesized that repeated sprint training in hypoxia could enhance repeated sprint ability (RSA performed in normoxia via improved glycolysis and O(2 utilization. 40 trained subjects completed 8 cycling repeated sprint sessions in hypoxia (RSH, 3000 m or normoxia (RSN, 485 m. Before (Pre- and after (Post- training, muscular levels of selected mRNAs were analyzed from resting muscle biopsies and RSA tested until exhaustion (10-s sprint, work-to-rest ratio 1:2 with muscle perfusion assessed by near-infrared spectroscopy. From Pre- to Post-, the average power output of all sprints in RSA was increased (p<0.01 to the same extent (6% vs 7%, NS in RSH and in RSN but the number of sprints to exhaustion was increased in RSH (9.4±4.8 vs. 13.0±6.2 sprints, p<0.01 but not in RSN (9.3±4.2 vs. 8.9±3.5. mRNA concentrations of HIF-1α (+55%, carbonic anhydrase III (+35% and monocarboxylate transporter-4 (+20% were augmented (p<0.05 whereas mitochondrial transcription factor A (-40%, peroxisome proliferator-activated receptor gamma coactivator 1α (-23% and monocarboxylate transporter-1 (-36% were decreased (p<0.01 in RSH only. Besides, the changes in total hemoglobin variations (Δ[tHb] during sprints throughout RSA test increased to a greater extent (p<0.01 in RSH. Our findings show larger improvement in repeated sprint performance in RSH than in RSN with significant molecular adaptations and larger blood perfusion variations in active muscles.

  17. Effects of caffeine and carbohydrate mouth rinses on repeated sprint performance.

    Science.gov (United States)

    Beaven, C Martyn; Maulder, Peter; Pooley, Adrian; Kilduff, Liam; Cook, Christian

    2013-06-01

    Our purpose was to examine the effectiveness of carbohydrate and caffeine mouth rinses in enhancing repeated sprint ability. Previously, studies have shown that a carbohydrate mouth rinse (without ingestion) has beneficial effects on endurance performance that are related to changes in brain activity. Caffeine ingestion has also demonstrated positive effects on sprint performance. However, the effects of carbohydrate or caffeine mouth rinses on intermittent sprints have not been examined previously. Twelve males performed 5 × 6-s sprints interspersed with 24 s of active recovery on a cycle ergometer. Twenty-five milliliters of either a noncaloric placebo, a 6% glucose, or a 1.2% caffeine solution was rinsed in the mouth for 5 s prior to each sprint in a double-blinded and balanced cross-over design. Postexercise maximal heart rate and perceived exertion were recorded, along with power measures. A second experiment compared a combined caffeine-carbohydrate rinse with carbohydrate only. Compared with the placebo mouth rinse, carbohydrate substantially increased peak power in sprint 1 (22.1 ± 19.5 W; Cohen's effect size (ES), 0.81), and both caffeine (26.9 ± 26.9 W; ES, 0.71) and carbohydrate (39.1 ± 25.8 W; ES, 1.08) improved mean power in sprint 1. Experiment 2 demonstrated that a combination of caffeine and carbohydrate improved sprint 1 power production compared with carbohydrate alone (36.0 ± 37.3 W; ES, 0.81). We conclude that carbohydrate and (or) caffeine mouth rinses may rapidly enhance power production, which could have benefits for specific short sprint exercise performance. The ability of a mouth-rinse intervention to rapidly improve maximal exercise performance in the absence of fatigue suggests a central mechanism.

  18. Barriers facing junior doctors in rural practice.

    Science.gov (United States)

    Smith, Deborah M

    2005-01-01

    Early postgraduate, or junior doctors, are still required to practise in rural and remote communities, and they continue to face numerous issues and difficulties. Within the hospital setting, exposure to rural practice appears to be very limited during internship, and also to some extent, during the second postgraduate year and beyond. This is a major issue for those required to undertake country relieving, rural terms or who will be bonded to rural and remote practice for several years after internship. This research investigated the current issues and difficulties faced by junior doctors, required to undertake rural and remote practice in Queensland, Australia. An exploratory study was undertaken. Primary data were collected through semi-structured interviews held with key stakeholders. Stakeholders included: directors of clinical training; medical educators; junior doctors; rural practitioners; academic rural practitioners; and medical administrators. Of the 23 people approached, a total of 19 agreed to be interviewed. The response rate was 82.6%. Similar to the issues identified in the literature, there are currently a number of barriers influencing the ability of junior doctors to practise competently and confidently when undertaking practice in rural and remote communities. Minimal clinical experience, lack of supervision and on-site support, inadequate orientation and uninformed expectations, limited access to relevant education, and the influence of isolation, results in an overall lack of preparation both professionally and personally. When asked, respondents supported the identification of core skills and knowledge, and integration of these and other issues affecting rural practice, into their hospital-based programs. Current hospital-based education and training programs were not adequately preparing junior doctors for rural and remote practice. It was commented that orientation and education, with a rural emphasis, could assist junior doctors in their

  19. Anthropometric factors related to sprint and agility performance in young male soccer players

    Directory of Open Access Journals (Sweden)

    Mathisen G

    2015-11-01

    Full Text Available Gunnar Mathisen, Svein Arne Pettersen School of Sport Sciences, UiT The Arctic University of Norway, Tromsø, Norway Objective: To investigate the relationship between anthropometrics and sprint and agility performance and describe the development of sprint (acceleration and agility performance in 10- to 16-year-old male soccer players. Methods: One hundred and thirty-two participants were divided into three age groups, 10–12 years (mean 10.8±0.50, 13–14 years (mean 13.9±0.50, and 15–16 years (mean 15.5±0.24, with assessment of 20 m sprint with 10 m split time and agility performance related to body height and body mass within groups. Results: In the 10- to 12-year-olds, there were no significant correlations between height, weight, and the performance variables, except for body mass, which was correlated to 10–20 m sprint (r=0.30. In the 13- to 14-year-olds, body height was significantly correlated with 10 m sprint (r=0.50 and 20 m sprint (r=0.52, as well as 10–20 m sprint (r=0.50 and agility performance (r=0.28. In the 15- to 16-year-old group, body height was correlated to 20 m (r=0.38 and 10–20 m (r=0.45 sprint. Body mass was significantly correlated to 10 m spring (r=0.35 in the 13- to 14-year-olds, as well as 20 m (r=0.33 and 10–20 m (r=0.35 sprint in the 15- to 16-year-olds. Conclusion: Height and body mass were significantly correlated with sprint performance in 13- to 16-year-old male soccer players. However, the 10- to 12-year-olds showed no significant relationship between sprint performance and anthropometrics, except for a small correlation in 10–20 m sprint. This may be attributed to maturation, with large differences in body height and body mass due to different patterns in the growth spurt. The agility performance related to anthropometrics was insignificant apart from a moderate correlation in the 13- to 14-year-olds. Keywords: youth soccer, running speed, development, football, puberty, skills 

  20. 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

  1. Improvement of Sprint Performance in Wheelchair Sportsmen With Caffeine Supplementation.

    Science.gov (United States)

    Graham-Paulson, Terri S; Perret, Claudio; Watson, Phil; Goosey-Tolfrey, Victoria L

    2016-03-01

    Caffeine can be beneficial during endurance and repeated-sprint exercise in able-bodied individuals performing leg or whole-body exercise. However, little evidence exists regarding its effects during upper-body exercise. This study therefore aimed to investigate the effects of caffeine on sprint (SPR) and 4-min maximal-push (PUSH) performance in wheelchair sportsmen. Using a double-blind, placebo-controlled, crossover design, 12 male wheelchair rugby players (age 30.0 ± 7.7 y, body mass 69.6 ± 15.3 kg, training 11.1 ± 3.5 h/wk) completed 2 exercise trials, separated by 7-14 d, 70 min after ingestion of 4 mg/kg caffeine (CAF) or dextrose placebo (PLA). Each trial consisted of four 4-min PUSHes and 3 sets of 3 × 20-m SPRs, each separated by 4 min rest. Participants responded to the Felt Arousal (a measure of perceived arousal), Feeling (a measure of the affective dimension of pleasure/displeasure), and rating-of-perceived-exertion (RPE) scales. Salivary caffeine secretion rates were measured. Average SPR times were faster during CAF than PLA during SPR 1 and SPR 2 (P = .037 and .016). There was no influence of supplementation on PUSHes 2-4 (P > .099); however, participants pushed significantly farther during PUSH 1 after CAF than after PLA (mean ± SD 677 ± 107 and 653 ± 118 m, P = .047). There was no influence of CAF on arousal or RPE scores (P > .132). Feeling scores improved over the course of the CAF trial only (P = .017) but did not significantly differ between trials (P > .167). Pre-warm-up (45 min postingestion) salivary CAF secretion rates were 1.05 ± 0.94 and 0.08 ± 0.05 μg/min for CAF and PLA, respectively. Acute CAF supplementation can improve both 20-m-sprint performance and a 1-off bout of short-term endurance performance in wheelchair sportsmen.

  2. Mechanics of the human hamstring muscles during sprinting.

    Science.gov (United States)

    Schache, Anthony G; Dorn, Tim W; Blanch, Peter D; Brown, Nicholas A T; Pandy, Marcus G

    2012-04-01

    An understanding of hamstring mechanics during sprinting is important for elucidating why these muscles are so vulnerable to acute strain-type injury. The purpose of this study was twofold: first, to quantify the biomechanical load (specifically, musculotendon strain, velocity, force, power, and work) experienced by the hamstrings across a full stride cycle; and second, to determine how these parameters differ for each hamstring muscle (i.e., semimembranosus (SM), semitendinosus (ST), biceps femoris long head (BF), biceps femoris short head (BF)). Full-body kinematics and ground reaction force data were recorded simultaneously from seven subjects while sprinting on an indoor running track. Experimental data were integrated with a three-dimensional musculoskeletal computer model comprised of 12 body segments and 92 musculotendon structures. The model was used in conjunction with an optimization algorithm to calculate musculotendon strain, velocity, force, power, and work for the hamstrings. SM, ST, and BF all reached peak strain, produced peak force, and formed much negative work (energy absorption) during terminal swing. The biomechanical load differed for each hamstring muscle: BF exhibited the largest peak strain, ST displayed the greatest lengthening velocity, and SM produced the highest peak force, absorbed and generated the most power, and performed the largest amount of positive and negative work. As peak musculotendon force and strain for BF, ST, and SM occurred around the same time during terminal swing, it is suggested that this period in the stride cycle may be when the biarticular hamstrings are at greatest injury risk. On this basis, hamstring injury prevention or rehabilitation programs should preferentially target strengthening exercises that involve eccentric contractions performed with high loads at longer musculotendon lengths.

  3. ENERGY EXPENDITURE AND HABITUAL PHYSICAL ACTIVITIES IN ADOLESCENT SPRINT ATHLETES

    Directory of Open Access Journals (Sweden)

    Dirk Aerenhouts

    2011-06-01

    Full Text Available This study aimed to assess total energy expenditure (TEE and specific habitual physical activities in adolescent sprint athletes. Two methods used to estimate TEE, an activity diary (AD and SenseWear armband (SWA, were compared. Sixteen athletes (6 girls, 10 boys, mean age 16.5 ± 1.6 yr simultaneously wore a SWA and completed an AD and food diary during one week. Basal energy expenditure as given by the SWA when taken off was corrected for the appropriate MET value using the AD. TEE as estimated by the AD and SWA was comparable (3196 ± 590 kcal and 3012 ± 518 kcal, p = 0.113 without day-to-day variations in TEE and energy expended in activities of high intensity. Daily energy intake (2569 ± 508 kcal did not match TEE according to both the AD and SWA (respectively p < 0.001 and p = 0.007. Athletes were in a supine position for a longer time on weekend days than on week days and slept longer on Sundays. Athletes reported a longer time of high-intensive physical activities in the AD than registered by the SWA on 4 out of 7 days. In addition to specific sprint activities on 3 to 7 days per week, 11 out of 16 athletes actively commuted to school where they participated in sports once or twice per week. The AD and the SWA are comparable in the estimation of TEE, which appears realistic and sustainable. The SWA offers an appropriate and objective method in the assessment of TEE, sleeping and resting in adolescent athletes on the condition that detailed information is given for the times the armband is not worn. The AD offers activity specific information but relies on the motivation, compliance and subjectivity of the individual, especially considering high-intensive intermittent training

  4. When Is a Sprint a Sprint? A Review of the Analysis of Team-Sport Athlete Activity Profile

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    Alice J. Sweeting

    2017-06-01

    Full Text Available The external load of a team-sport athlete can be measured by tracking technologies, including global positioning systems (GPS, local positioning systems (LPS, and vision-based systems. These technologies allow for the calculation of displacement, velocity and acceleration during a match or training session. The accurate quantification of these variables is critical so that meaningful changes in team-sport athlete external load can be detected. High-velocity running, including sprinting, may be important for specific team-sport match activities, including evading an opponent or creating a shot on goal. Maximal accelerations are energetically demanding and frequently occur from a low velocity during team-sport matches. Despite extensive research, conjecture exists regarding the thresholds by which to classify the high velocity and acceleration activity of a team-sport athlete. There is currently no consensus on the definition of a sprint or acceleration effort, even within a single sport. The aim of this narrative review was to examine the varying velocity and acceleration thresholds reported in athlete activity profiling. The purposes of this review were therefore to (1 identify the various thresholds used to classify high-velocity or -intensity running plus accelerations; (2 examine the impact of individualized thresholds on reported team-sport activity profile; (3 evaluate the use of thresholds for court-based team-sports and; (4 discuss potential areas for future research. The presentation of velocity thresholds as a single value, with equivocal qualitative descriptors, is confusing when data lies between two thresholds. In Australian football, sprint efforts have been defined as activity >4.00 or >4.17 m·s−1. Acceleration thresholds differ across the literature, with >1.11, 2.78, 3.00, and 4.00 m·s−2 utilized across a number of sports. It is difficult to compare literature on field-based sports due to inconsistencies in velocity and

  5. Rock-dwelling lizards exhibit less sensitivity of sprint speed to increases in substrate rugosity.

    Science.gov (United States)

    Collins, Clint E; Self, Jessica D; Anderson, Roger A; McBrayer, Lance D

    2013-06-01

    Effectively moving across variable substrates is important to all terrestrial animals. The effects of substrates on lizard performance have ecological ramifications including the partitioning of habitat according to sprinting ability on different surfaces. This phenomenon is known as sprint sensitivity, or the decrease in sprint speed due to change in substrate. However, sprint sensitivity has been characterized only in arboreal Anolis lizards. Our study measured sensitivity to substrate rugosity among six lizard species that occupy rocky, sandy, and/or arboreal habitats. Lizards that use rocky habitats are less sensitive to changes in substrate rugosity, followed by arboreal lizards, and then by lizards that use sandy habitats. We infer from comparative phylogenetic analysis that forelimb, chest, and tail dimensions are important external morphological features related to sensitivity to changes in substrate rugosity. Copyright © 2013 Elsevier GmbH. All rights reserved.

  6. Comparison of step-by-step kinematics of resisted, assisted and unloaded 20-m sprint runs.

    Science.gov (United States)

    van den Tillaar, Roland; Gamble, Paul

    2018-03-26

    This investigation examined step-by-step kinematics of sprint running acceleration. Using a randomised counterbalanced approach, 37 female team handball players (age 17.8 ± 1.6 years, body mass 69.6 ± 9.1 kg, height 1.74 ± 0.06 m) performed resisted, assisted and unloaded 20-m sprints within a single session. 20-m sprint times and step velocity, as well as step length, step frequency, contact and flight times of each step were evaluated for each condition with a laser gun and an infrared mat. Almost all measured parameters were altered for each step under the resisted and assisted sprint conditions (η 2  ≥ 0.28). The exception was step frequency, which did not differ between assisted and normal sprints. Contact time, flight time and step frequency at almost each step were different between 'fast' vs. 'slow' sub-groups (η 2  ≥ 0.22). Nevertheless overall both groups responded similarly to the respective sprint conditions. No significant differences in step length were observed between groups for the respective condition. It is possible that continued exposure to assisted sprinting might allow the female team-sports players studied to adapt their coordination to the 'over-speed' condition and increase step frequency. It is notable that step-by-step kinematics in these sprints were easy to obtain using relatively inexpensive equipment with possibilities of direct feedback.

  7. Postactivation Potentation Effects From Accommodating Resistance Combined With Heavy Back Squats on Short Sprint Performance.

    Science.gov (United States)

    Wyland, Timothy P; Van Dorin, Joshua D; Reyes, G Francis Cisco

    2015-11-01

    Applying accommodating resistance combined with isoinertial resistance has been demonstrated to be effective in improving neuromuscular attributes important for sport performance. The main purpose of this study was to determine whether short sprints can be acutely enhanced after several sets of back squats with or without accommodating resistance. Twenty recreationally resistance-trained males (age: 23.3 ± 4.4 years; height: 178.9 ± 6.5 cm; weight: 88.3 ± 10.8 kg) performed pre-post testing on 9.1-m sprint time. Three different interventions were implemented in randomized order between pre-post 9.1-m sprints. On 3 separate days, subjects either sat for 5 minutes (CTRL), performed 5 sets of 3 repetitions at 85% of their 1 repetition maximum (1RM) with isoinertial load (STND), or performed 5 sets of 3 repetitions at 85% of their 1RM, with 30% of the total resistance coming from elastic band tension (BAND) between pre-post 9.1-m sprint testing. Posttesting for 9.1-m sprint time occurred immediately after the last set of squats (Post-Immediate) and on every minute for 4 minutes after the last set of squats (Post-1min, Post-2min, Post-3min, and Post-4min). Repeated-measures analysis of variance statistical analyses revealed no significant changes in sprint time across posttesting times during the CTRL and STND condition. During the BAND condition, sprint time significantly decreased from Post-Immediate to Post-4min (p = 0.002). The uniqueness of accommodating resistance could create an optimal postactivation potentiation effect to increase neuromuscular performance. Coaches and athletes can implement heavy accommodating resistance exercises to their warm-up when improving acute sprint time is desired.

  8. Effect of Beta alanine and sodium bicarbonate supplementation on repeated-sprint performance.

    Science.gov (United States)

    Ducker, Kagan J; Dawson, Brian; Wallman, Karen E

    2013-12-01

    This study aimed to investigate if combining beta alanine (BA) and sodium bicarbonate (NaHCO3) supplementation could lead to enhanced repeated-sprint performance in team-sport athletes, beyond what is possible with either supplement alone. Participants (n = 24) completed duplicate trials of a repeated-sprint test (3 sets; 6 × 20 m departing every 25 seconds, 4 minutes active recovery between sets) and were then allocated into 4 groups as follows: BA only (n = 6; 28 days BA, acute sodium chloride placebo); NaHCO3 only (n = 6; 28 days glucose placebo, acute NaHCO3); BA/NaHCO3 (n = 6; 28 days BA, acute NaHCO3); placebo only (n = 6; 28 days glucose placebo, acute sodium chloride placebo), then completed duplicate trials postsupplementation. Sodium bicarbonate alone resulted in moderate effect size (d = 0.40-0.71) and "likely" and "very likely" benefit for overall total sprint times (TST) and for each individual set and for first sprint (sets 2 and 3) and best sprint time (sets 2 and 3). Combining BA and NaHCO3 resulted in "possible" to "likely" benefits for overall TST and for sets 2 and 3. First sprint (set 3) and best sprint time (sets 2 and 3) also showed "likely" benefit after this trial. The BA and placebo groups showed no differences in performance after supplementation. In conclusion, these results indicate that supplementation with acute NaHCO3 improved repeated-sprint performance more than either a combination of NaHCO3 and BA or BA alone.

  9. The Characteristics of Static Plantar Loading in the First-Division College Sprint Athletes

    OpenAIRE

    Tong-Hsien Chow

    2016-01-01

    Background: Plantar pressure measurement is an effective method for assessing plantar loading and can be applied to evaluating movement performance of the foot. The purpose of this study is to explore the sprint athletes' plantar loading characteristics and pain profiles in static standing. Methods: Experiments were undertaken on 80 first-division college sprint athletes and 85 healthy non-sprinters. 'JC Mat', the optical plantar pressure measurement was applied to examining the differences b...

  10. The effect of hamstring flexibility on peak hamstring muscle strain in sprinting

    OpenAIRE

    Xianglin Wan; Feng Qu; William E. Garrett; Hui Liu; Bing Yu

    2017-01-01

    Background: The effect of hamstring flexibility on the peak hamstring muscle strains in sprinting, until now, remained unknown, which limited our understanding of risk factors of hamstring muscle strain injury (hamstring injury). As a continuation of our previous study, this study was aimed to examine the relationship between hamstring flexibility and peak hamstring muscle strains in sprinting. Methods: Ten male and 10 female college students participated in this study. Hamstring flexibili...

  11. Effects of coffee and caffeine anhydrous on strength and sprint performance.

    Science.gov (United States)

    Trexler, Eric T; Smith-Ryan, Abbie E; Roelofs, Erica J; Hirsch, Katie R; Mock, Meredith G

    2016-09-01

    Caffeine and coffee are widely used among active individuals to enhance performance. The purpose of the current study was to compare the effects of acute coffee (COF) and caffeine anhydrous (CAF) intake on strength and sprint performance. Fifty-four resistance-trained males completed strength testing, consisting of one-rep max (1RM) and repetitions to fatigue (RTF) at 80% of 1RM for leg press (LP) and bench press (BP). Participants then completed five, 10-second cycle ergometer sprints separated by one minute of rest. Peak power (PP) and total work (TW) were recorded for each sprint. At least 48 hours later, participants returned and ingested a beverage containing CAF (300 mg flat dose; yielding 3-5 mg/kg bodyweight), COF (8.9 g; 303 mg caffeine), or placebo (PLA; 3.8 g non-caloric flavouring) 30 minutes before testing. LP 1RM was improved more by COF than CAF (p = .04), but not PLA (p = .99). Significant interactions were not observed for BP 1RM, BP RTF, or LP RTF (p > .05). There were no sprint × treatment interactions for PP or TW (p > .05). 95% confidence intervals revealed a significant improvement in sprint 1 TW for CAF, but not COF or PLA. For PLA, significant reductions were observed in sprint 4 PP, sprint 2 TW, sprint 4 TW, and average TW; significant reductions were not observed with CAF or COF. Neither COF nor CAF improved strength outcomes more than PLA, while both groups attenuated sprint power reductions to a similar degree. Coffee and caffeine anhydrous may be considered suitable pre-exercise caffeine sources for high-intensity exercise.

  12. Effects of sodium phosphate and caffeine ingestion on repeated-sprint ability in male athletes.

    Science.gov (United States)

    Kopec, Benjamin J; Dawson, Brian T; Buck, Christopher; Wallman, Karen E

    2016-03-01

    To assess the effects of sodium phosphate (SP) and caffeine supplementation on repeated-sprint performance. Randomized, double-blind, Latin-square design. Eleven team-sport males participated in four trials: (1) SP (50mgkg(-1) of free fat-mass daily for six days) and caffeine (6mgkg(-1) ingested 1h before exercise); SP+C, (2) SP and placebo (for caffeine), (3) caffeine and placebo (for SP) and (4) placebo (for SP and caffeine). After loading, participants performed a simulated team-game circuit (STGC) consisting of 2×30min halves, with 6×20-m repeated-sprint sets performed at the start, half-time and end of the STGC. There were no interaction effects between trials for first-sprint (FS), best-sprint (BS) or total-sprint (TS) times (p>0.05). However, SP resulted in the fastest times for all sprints, as supported by moderate to large effect sizes (ES; d=0.51-0.83) and 'likely' to 'very likely' chances of benefit, compared with placebo. Compared with caffeine, SP resulted in 'possible' to 'likely' chances of benefit for FS, BS and TS for numerous sets and a 'possible' chance of benefit compared with SP+C for BS (set 2). Compared with placebo, SP+C resulted in moderate ES (d=0.50-0.62) and 'possible' to 'likely' benefit for numerous sprints, while caffeine resulted in a moderate ES (d=0.63; FS: set 3) and 'likely' chances of benefit for a number of sets. While not significant, ES and qualitative analysis results suggest that SP supplementation may improve repeated-sprint performance when compared with placebo. Copyright © 2015 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  13. Heart rate and time-motion analyses in top junior players during basketball matches

    Directory of Open Access Journals (Sweden)

    Karel Hůlka

    2013-09-01

    Full Text Available BACKGROUND: Basketball performance can be classified as an intermittent physical activity due to the changing situational game conditions and the number of intervening variables. It is necessary to have detailed knowledge about the performance of basketball players during a match as a background for more specific planning of the training process. OBJECTIVE: The aim of this study was to analyse the indicators of internal and external load of basketball player’s performance during a match of U18 top men basketball players as a background for the planning of specific training processes. METHODS: Thirty-two Czech top junior basketball players (male, aged 16.88 ± 0.72 years participated in this research. The heart rate was recorded and time-motion analysis was conducted during six warm-up matches. RESULTS: The average heart rate was measured to be 167.47 ± 13.01 beats • min.–1, which corresponded to 85.06 ± 6.40% of peak heart rate. The percentages of the total time spent over and under 85% were 63.12% and 36.88%, respectively. Average distance covered was measured to be 5,880.91 ± 831.01 meters. The average work : rest ratio was 1 : 7.95 ± 1.83, ranging from 1 : 4.80 to 1 : 10.92. CONCLUSIONS: The results from these matches suggest that the exercise intensity and sprint activity observed during junior basketball are dependent on the player's position and partly on the level of the performance. The heart rate during a match was not dependent on the positions, however, time-motion analysis revealed significant differences between three basketball positions during a match. The combination of heart rate and time-motion analysis is recommended.

  14. Junior Sport and the Evolution of Sport Cultures.

    Science.gov (United States)

    Siedentop, Daryl

    2002-01-01

    Addresses junior sport and sport culture in New Zealand, recommending that it receive serious consideration for its crucial role in the future of New Zealand's sport culture. The paper presents three goals for junior sport programs (educative, public health, and elite development), describes characteristics of junior sport (e.g., youth want to…

  15. Reliability characteristics and applicability of a repeated sprint ability test in male young soccer players

    DEFF Research Database (Denmark)

    Castagna, Carlo; Francini, Lorenzo; Krustrup, Peter

    2018-01-01

    The aim of this study was to examine the usefulness and reliability characteristics of a repeated sprint ability test considering 5 line sprints of 30-m interspersed with 30-s of active recovery in non-elite outfield young male soccer players. Twenty-six (age 14.9±1.2 years, height 1.72±0.12 cm......, body mass 62.2±5.1 kg) players were tested 48 hours and 7 days apart for 5x30-m performance over 5 trials (T1-T5). Short- (T1-T2) and long-term reliability (T1-T3-T4-T5) were assessed with Intraclass Correlation Coefficient (ICC) and with typical error for measurement (TEM). Short- and long...... study revealed that the 5x30-m sprint test is a reliable field test in the short and long-term when the sum of sprint times and the best sprint performance are considered as outcome variables. Sprint performance decrements variables showed large variability across trials....

  16. The impact of dry-land sprint start training on the short track speed skating start.

    Science.gov (United States)

    Haug, William B; Drinkwater, Eric J; Cicero, Nicholas J; Barthell, J Anthony; Chapman, Dale W

    2017-05-05

    This investigation sought to determine the effects of dry-land sprint start training on short track speed skating (STSS) start performance. Nine highly trained short track athletes completed a control period of normal STSS training followed by a four-week training intervention. Before and after the control and intervention periods, athletes performed three electronically timed dry-land and on-ice 14.43 m maximal sprint start efforts. The intervention consisted of two sprint sessions per week consisting of nine electronically timed 14.43 m dry-land sprint starts in addition to normal STSS training. The control period resulted in no substantial change in on-ice start performance (Mean Δ: -0.01 s, 95% Confidence Limits (CL): -0.08 to 0.05 s; Effect Size (ES): -0.05; Trivial) however, a small change was observed in dry-land start performance (Mean Δ: -0.07 s, 95% CL: -0.13 to -0.02 s; ES: -0.49). Following brief specific dry-land sprint start training a small improvement was observed in both on-ice (Mean Δ: -0.07 s, 95% CL: -0.13 to -0.01 s; ES: -0.33) and dry-land (Mean Δ: -0.04 s, 95% CL: -0.09 to 0.00 s; ES: -0.29) start performance. This investigation suggests STSS start performance can be improved through a brief dry-land sprint start training program.

  17. Intermittent-sprint performance and muscle glycogen after 30 h of sleep deprivation.

    Science.gov (United States)

    Skein, Melissa; Duffield, Rob; Edge, Johann; Short, Michael J; Mündel, Toby

    2011-07-01

    The aim of this study was to determine the effects of 30 h of sleep deprivation on consecutive-day intermittent-sprint performance and muscle glycogen content. Ten male, team-sport athletes performed a single-day "baseline" session and two consecutive-day experimental trials separated either by a normal night's sleep (CONT1 and CONT2) or no sleep (SDEP1 and SDEP2). Each session included a 30-min graded exercise run and 50-min intermittent-sprint exercise protocol, including a 15-m maximal sprint every minute and self-paced exercise bouts of varying intensities. Muscle biopsies were extracted before and after exercise during the baseline session and before exercise on day 2 during experimental trials. Voluntary force and activation of the right quadriceps, nude mass, HR, core temperature, capillary blood lactate and glucose, RPE, and a modified POMS were recorded before, after, and during the exercise protocols. Mean sprint times were slower on SDEP2 (2.78±0.17 s) compared with SDEP1 (2.70±0.16 s) and CONT2 (2.74±0.15 s, PSleep loss did not affect RPE but negatively affected POMS ratings (PSleep loss and associated reductions in muscle glycogen and perceptual stress reduced sprint performance and slowed pacing strategies during intermittent-sprint exercise for male team-sport athletes.

  18. Reductions in Sprint Paddling Ability and Countermovement Jump Performance After Surfing Training.

    Science.gov (United States)

    Secomb, Josh L; Sheppard, Jeremy M; Dascombe, Ben J

    2015-07-01

    The present study aimed to determine whether any meaningful change in a surfer's sprint paddling ability and countermovement jump (CMJ) performance developed after a 2-hour surfing training session and also whether any physical demands of the surfing session were related to the resultant changes in the capacities. Fifteen competitive male surfing athletes (age, 22.1 ± 3.9 years; height, 175.4 ± 6.4 cm; body mass, 72.5 ± 7.7 kg) performed a 2-hour surfing training session, with 15-m sprint paddle and CMJ trials performed both before and after the surfing session. Pre- to posttesting measures were analyzed using magnitude-based inferences. Likely declines were observed in the velocity achieved at the 5-, 10-, and 15-m splits of the 15-m sprint paddle, as well as peak velocity. Similarly, likely declines were calculated for CMJ peak force, relative peak force, and jump height. Furthermore, large correlations were calculated between presurfing session peak velocity and the change in 5, 10, 15 m, and peak velocity of the 15-m sprint paddle and total distance covered, wave riding bouts, and success rate. Surfing athletes and coaches may need to consider implementing shorter duration training sessions to reduce the decline in sprint paddling ability and CMJ performance. Furthermore, surfing athletes should possess highly developed sprint paddling ability because this may allow them to undertake a greater workload and catch more waves, which will increase the opportunity for technical refinement of maneuvers and skill acquisition.

  19. Correlating continuous assessment scores to junior secondary ...

    African Journals Online (AJOL)

    This study investigated the relationship between continuous assessment scores and junior secondary school certificate examination(JSCE) final scores in Imo State. A sample of four hundred students were purposively selected from thirty eight thousand students who took the 1997 JSCE in Imo State. The data used were ...

  20. Skills training of junior medical students

    African Journals Online (AJOL)

    2013-11-02

    Nov 2, 2013 ... Peer tutors enjoyed and benefited from this teaching method without it negatively affecting their own learning. Discussion. ... addressing the problem of skills training of junior medical students where there is a shortage of trained clinical teachers. AJHPE 2013 ... [1] Informal peer teaching usually takes place.

  1. Reproductive Health Knowledge And Practices Among Junior ...

    African Journals Online (AJOL)

    Methods: A cross sectional survey of the reproductive health knowledge and practices of 412 junior secondary school pupils from 12 schools in Enugu State, Nigeria was undertaken using a uniform set of structured self-administered questionnaire. Results: The results revealed that while the pupils demonstrated fair ...

  2. HUMANITIES IN A JUNIOR HIGH SCHOOL.

    Science.gov (United States)

    KNIGHT, BONNIE M.

    A HUMANITIES COURSE HAS BEEN DEVELOPED FOR ACADEMICALLY ABLE SEVENTH-GRADE STUDENTS IN BRANCIFORTE JUNIOR HIGH SCHOOL IN SANTA CRUZ, CALIFORNIA. IN A TWO-PERIOD DAILY TIME BLOCK, STUDENTS LEARN ENGLISH, LITERATURE, AND LATIN, AND INVESTIGATE TOPICS IN ARCHEOLOGY, CULTURAL ANTHROPOLOGY, LINGUISTICS, PSYCHOLOGY, PHILOSOPHY, GREEK LITERATURE AND…

  3. Report: Immersion French at Meriden Junior School

    Science.gov (United States)

    Esposito, Marie-Josee

    2006-01-01

    In this article, the author describes the French immersion program at Meriden Junior School, an Anglican school for girls from pre-Kindergarten to Year 12 in Sydney. Four teachers (one of whom is the coordinator) and three assistants are involved in the program. They include six French native speakers and one non-French-born teacher who speaks…

  4. Junior High School Pupils' Perceptions of Air

    African Journals Online (AJOL)

    cce

    learning of science at the basic level. ... Stavy (1991) reported that students in his physics class had ... In a cross-level study of junior secondary, senior secondary and .... interview guide consisted of the items culled from Section B of the test.

  5. Percentile Values for Running Sprint Field Tests in Children Ages 6-17 Years: Influence of Weight Status

    Science.gov (United States)

    Castro-Pinero, Jose; Gonzalez-Montesinos, Jose Luis; Keating, Xiaofen D.; Mora, Jesus; Sjostrom, Michael; Ruiz, Jonatan R.

    2010-01-01

    The aim of this study was to provide percentile values for six different sprint tests in 2,708 Spanish children (1,234 girls) ages 6-17.9 years. We also examined the influence of weight status on sprint performance across age groups, with a focus on underweight and obese groups. We used the 20-m, 30-m, and 50-m running sprint standing start and…

  6. The association between fundamental athletic movements and physical fitness in elite junior Australian footballers.

    Science.gov (United States)

    Woods, Carl T; McKeown, Ian; Keogh, Justin; Robertson, Sam

    2018-02-01

    This study investigated the associations between fundamental athletic movement and physical fitness in junior Australian football (AF). Forty-four under 18 players performed a fundamental athletic movement assessment consisting of an overhead squat, double lunge, single leg Romanian deadlift and a push up. Movements were scored on three assessment criterions using a three-point scale. Additionally, participants performed five physical fitness tests commonly used for talent identification in AF. A Spearman's nonparametric correlation matrix was built, with correlation coefficients being visualised using a circularly rendered correlogram. Score on the overhead squat was moderately positively associated with dynamic vertical jump height on left (r s  = 0.40; P ≤ 0.05) and right (r s  = 0.30; P ≤ 0.05) leg take-off, stationary vertical jump (r s  = 0.32; P ≤ 0.05) and negatively associated with 20-m sprint time (r s  = -0.35; P ≤ 0.05). Score on the double lunge (left/right side) was moderately positively associated with the same physical fitness tests as well as score on the multistage fitness test. Results suggest that improvements in physical fitness qualities may occur through concurrent increases in fundamental athletic movement skill, namely the overhead squat and double lunge movements. These findings may assist with the identification and development of talent.

  7. Effects of Repeated-Sprint Training in Hypoxia on Sea-Level Performance: A Meta-Analysis.

    Science.gov (United States)

    Brocherie, Franck; Girard, Olivier; Faiss, Raphaël; Millet, Grégoire P

    2017-08-01

    Repeated-sprint training in hypoxia (RSH) is a recent intervention regarding which numerous studies have reported effects on sea-level physical performance outcomes that are debated. No previous study has performed a meta-analysis of the effects of RSH. We systematically reviewed the literature and meta-analyzed the effects of RSH versus repeated-sprint training in normoxia (RSN) on key components of sea-level physical performance, i.e., best and mean (all sprint) performance during repeated-sprint exercise and aerobic capacity (i.e., maximal oxygen uptake [[Formula: see text

  8. Effects of Plyometric and Sprint Training on Physical and Technical Skill Performance in Adolescent Soccer Players.

    Science.gov (United States)

    Sáez de Villarreal, Eduardo; Suarez-Arrones, Luis; Requena, Bernardo; Haff, Gregory G; Ferrete, Carlos

    2015-07-01

    To determine the influence of a short-term combined plyometric and sprint training (9 weeks) within regular soccer practice on explosive and technical actions of pubertal soccer players during the in-season. Twenty-six players were randomly assigned to 2 groups: control group (CG) (soccer training only) and combined group (CombG) (plyometric + acceleration + dribbling + shooting). All players trained soccer 4 times per week and the experimental groups supplemented the soccer training with a proposed plyometric-sprint training program for 40 minutes (2 days per weeks). Ten-meter sprint, 10-m agility with and without ball, CMJ and Abalakov vertical jump, ball-shooting speed, and Yo-Yo intermittent endurance test were measured before and after training. The experimental group followed a 9-week plyometric and sprint program (i.e., jumping, hurdling, bouncing, skipping, and footwork) implemented before the soccer training. Baseline-training results showed no significant differences between the groups in any of the variables tested. No improvement was found in the CG; however, meaningful improvement was found in all variables in the experimental group: CMJ (effect size [ES] = 0.9), Abalakov vertical jump (ES = 1.3), 10-m sprint (ES = 0.7-0.9), 10-m agility (ES = 0.8-1.2), and ball-shooting speed (ES = 0.7-0.8). A specific combined plyometric and sprint training within regular soccer practice improved explosive actions compared with conventional soccer training only. Therefore, the short-term combined program had a beneficial impact on explosive actions, such as sprinting, change of direction, jumping, and ball-shooting speed which are important determinants of match-winning actions in soccer performance. Therefore, we propose modifications to current training methodology for pubertal soccer players to include combined plyometric and speed training for athlete preparation in this sport.

  9. The influence of parachute-resisted sprinting on running mechanics in collegiate track athletes.

    Science.gov (United States)

    Paulson, Sally; Braun, William A

    2011-06-01

    The influence of parachute-resisted sprinting on running mechanics in collegiate track athletes. The aim of this investigation was to compare the acute effects of parachute-resisted (PR) sprinting on selected kinematic variables. Twelve collegiate sprinters (mean age 19.58 ± 1.44 years, mass 69.32 ± 14.38 kg, height 1.71 ± 9.86 m) ran a 40-yd dash under 2 conditions: PR sprint and sprint without a parachute (NC) that were recorded on a video computer system (60 Hz). Sagittal plane kinematics of the right side of the body was digitized to calculate joint angles at initial ground contact (IGC) and end ground contact (EGC), ground contact (GC) time, stride rate (SR), stride length (SL), and the times of the 40-yd dashes. The NC 40-yd dash time was significantly faster than the PR trial (p 0.05). This study suggests that PR sprinting does not acutely affect GC time, SR, SL and upper extremity or lower extremity joint angles during weight acceptance (IGC) in collegiate sprinters. However, PR sprinting increased shoulder flexion by 23.5% at push-off and decreased speed by 4.4%. While sprinting with the parachute, the athlete's movement patterns resembled their mechanics during the unloaded condition. This indicates the external load caused by PR did not substantially overload the runner, and only caused a minor change in the shoulder during push-off. This sports-specific training apparatus may provide coaches with another method for training athletes in a sports-specific manner without causing acute changes to running mechanics.

  10. Effect of squatting on sprinting performance and repeated exposure to complex training in male rugby players.

    Science.gov (United States)

    Comyns, Thomas M; Harrison, Andrew J; Hennessy, Liam K

    2010-03-01

    This study was undertaken to examine the effect of a heavy weight training exercise on sprinting performance and on the effect of repeated exposure to a complex training protocol. Eleven male rugby union players (age 20.9 +/- 3.1 years) participated in the study, which involved 5 separate testing sessions. Back squat 3 repetition maximum (3RM) was established in session 1. Sessions 2-5 were identical and involved the subjects completing a 30-m sprint before and after a 3RM back squat protocol. Four minutes of rest was given between the back squatting and the posttest 30-m sprint. All sprint trials were measured with a laser measurement device (LAVEG, Jenoptik, Jena, Germany). Sprint time and instantaneous, average, and maximum velocity were the dependent variables. The criterion for significance was set at an alpha level of p > or = 0.05. No significant improvement was evident for any of the testing sessions (p > or = 0.05). In session 1, there was a significant increase in 30-m time and a significant reduction in average 30-m velocity and maximum velocity (p benefits in sprinting may not have been realized because of intra and intersubject variations in sprint technique. The session x phase interaction revealed a significant improvement in the pre to posttest changes in instantaneous velocity at 20 m (p = 0.035) and 30 m (p = 0.036) from session 1 to session 4. This indicates that the rugby players may be able to learn to apply the potentiation effects of complex training. From a practical perspective, players may need repeated exposure to this training modality to gain benefit from it, and this should be reflected in program planning.

  11. 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.

  12. Research Resources Survey: Radiology Junior Faculty Development.

    Science.gov (United States)

    Krupinski, Elizabeth A; Votaw, John R

    2015-07-01

    To assess resources available to junior faculty in US academic radiology departments for research mentorship and funding opportunities and to determine if certain resources are more common in successful programs. An anonymous survey covering scientific environment and research mentorship and was sent to vice-chairs of research of radiology departments. Results were evaluated to identify practices of research programs with respect to mentorship, resources, and opportunities. Academy of Radiology Research's 2012 National Institutes of Health (NIH) grants and awards list was used to determine if environment and practices correlate with funding. There was a 51% response rate. A greater fraction of clinical faculty gets promoted from assistant to associate professor than research faculty. Research faculty overall submits more funding applications. Most programs support start-up costs and K-awards. Over half of the departments have a vice-chair for faculty development, and most have formal mentorship programs. Faculty members are expected to teach, engage in service, publish, and apply for and get research funding within 3 years of hire. Top-tier programs as judged by NIH awards have a combination of MDs who devote >50% effort to research and PhD faculty. Key factors holding back both clinical and research junior faculty development were motivation, resources, and time, although programs reported high availability of resources and support at the department level. Better marketing of resources for junior faculty, effort devoted to mentoring clinical faculty in research, and explicit milestones/expectations for achievement could enhance junior faculty success, promote interest in the clinician–scientist career path for radiologists, and lead to greater research success.

  13. Junior Leader Training Development in Operational Units

    Science.gov (United States)

    2012-04-01

    UNITS Successful operational units do not arise without tough, realistic, and challenging training. Field Manual (FM) 7-0, Training Units and D...operations. The manual provides junior leaders with guidance on how to conduct training and training management. Of particular importance is the definition...1 Relation htp between ADDIE and the Anny Training Management Model. The Army Training Management Model and ADDIE process appear in TRADOC PAM 350

  14. Ground Reaction Force and Cadence during Stationary Running Sprint in Water and on Land.

    Science.gov (United States)

    Fontana, H de Brito; Ruschel, C; Haupenthal, A; Hubert, M; Roesler, H

    2015-06-01

    This study was aimed at analyzing the cadence (Cadmax) and the peak vertical ground reaction force (Fymax) during stationary running sprint on dry land and at hip and chest level of water immersion. We hypothesized that both Fymax and Cadmax depend on the level of immersion and that differences in Cadmax between immersions do not affect Fymax during stationary sprint. 32 subjects performed the exercise at maximum cadence at each immersion level and data were collected with force plates. The results show that Cadmax and Fymax decrease 17 and 58% from dry land to chest immersion respectively, with no effect of cadence on Fymax. While previous studies have shown similar neuromuscular responses between aquatic and on land stationary sprint, our results emphasize the differences in Fymax between environments and levels of immersion. Additionally, the characteristics of this exercise permit maximum movement speed in water to be close to the maximum speed on dry land. The valuable combination of reduced risk of orthopedic trauma with similar neuromuscular responses is provided by the stationary sprint exercise in water. The results of this study support the rationale behind the prescription of stationary sprinting in sports training sessions as well as rehabilitation programs. © Georg Thieme Verlag KG Stuttgart · New York.

  15. Optimizing the physical conditioning of the NASCAR sprint cup pit crew athlete.

    Science.gov (United States)

    Ferguson, David P; Davis, Adam M; Lightfoot, J Timothy

    2015-03-01

    Stock car racing is the largest spectator sport in the United States. As a result, National Association for Stock Car Automobile Racing (NASCAR) Sprint Cup teams have begun to invest in strength and conditioning programs for their pit crew athletes. However, there is limited knowledge regarding the physical characteristics of elite NASCAR pit crew athletes, how the NASCAR Sprint Cup season affects basic physiological parameters such as body composition, and what is the most appropriate physical training program that meets the needs of a pit crew athlete. We conducted 3 experiments involving Sprint Cup motorsport athletes to determine predictors of success at the elite level, seasonal physiological changes, and appropriate physical training programs. Our results showed that hamstring flexibility (p = 0.015) and the score on the 2-tire front run test (p = 0.012) were significant predictors of NASCAR Sprint Cup Pit Crew athlete performance. Additionally, during the off season, pit crew athletes lost lean body mass, which did not return until the middle of the season. Therefore, a strength and conditioning program was developed to optimize pit crew athlete performance throughout the season. Implementation of this strength and conditioning program in 1 NASCAR Sprint Cup team demonstrated that pit crew athletes were able to prevent lean body mass loss and have increased muscle power output from the start of the season to the end of the season.

  16. Sprint Acceleration Mechanics: The Major Role of Hamstrings in Horizontal Force Production

    Science.gov (United States)

    Morin, Jean-Benoît; Gimenez, Philippe; Edouard, Pascal; Arnal, Pierrick; Jiménez-Reyes, Pedro; Samozino, Pierre; Brughelli, Matt; Mendiguchia, Jurdan

    2015-01-01

    Recent literature supports the importance of horizontal ground reaction force (GRF) production for sprint acceleration performance. Modeling and clinical studies have shown that the hip extensors are very likely contributors to sprint acceleration performance. We experimentally tested the role of the hip extensors in horizontal GRF production during short, maximal, treadmill sprint accelerations. Torque capabilities of the knee and hip extensors and flexors were assessed using an isokinetic dynamometer in 14 males familiar with sprint running. Then, during 6-s sprints on an instrumented motorized treadmill, horizontal and vertical GRF were synchronized with electromyographic (EMG) activity of the vastus lateralis, rectus femoris, biceps femoris, and gluteus maximus averaged over the first half of support, entire support, entire swing and end-of-swing phases. No significant correlations were found between isokinetic or EMG variables and horizontal GRF. Multiple linear regression analysis showed a significant relationship (P = 0.024) between horizontal GRF and the combination of biceps femoris EMG activity during the end of the swing and the knee flexors eccentric peak torque. In conclusion, subjects who produced the greatest amount of horizontal force were both able to highly activate their hamstring muscles just before ground contact and present high eccentric hamstring peak torque capability. PMID:26733889

  17. Sprint acceleration mechanics: the major role of hamstrings in horizontal force production

    Directory of Open Access Journals (Sweden)

    Jean-Benoit eMORIN

    2015-12-01

    Full Text Available Recent literature supports the importance of horizontal ground reaction force (GRF production for sprint acceleration performance. Modeling and clinical studies have shown that the hip extensors are very likely contributors to sprint acceleration performance. We experimentally tested the role of the hip extensors in horizontal GRF production during short, maximal, treadmill sprint accelerations. Torque capabilities of the knee and hip extensors and flexors were assessed using an isokinetic dynamometer in 14 males familiar with sprint running. Then, during 6-s sprints on an instrumented motorized treadmill, horizontal and vertical GRF were synchronized with electromyographic (EMG activity of the vastus lateralis, rectus femoris, biceps femoris and gluteus maximus averaged over the first half of support, entire support, entire swing and end-of-swing phases. No significant correlations were found between isokinetic or EMG variables and horizontal GRF. Multiple linear regression analysis showed a significant relationship (P = 0.024 between horizontal GRF and the combination of biceps femoris EMG activity during the end of the swing and the knee flexors eccentric peak torque. In conclusion, subjects who produced the greatest amount of horizontal force were both able to highly activate their hamstring muscles just before ground contact and present high eccentric hamstring peak torque capability.

  18. The Association of Sprint Performance with Anthropometric Parameters in Youth Soccer Players

    Directory of Open Access Journals (Sweden)

    Arjan Hyka

    2017-02-01

    Full Text Available Several studies have investigated the association between strength and speed, showing that stronger athletes perform better during sprint performances (Baker & Nance, 1999. Moreover, the aim of this study was to evaluate the correlation between sprint performance and anthropometric parameters. Subjects were 32 youth soccer players. The age of participants was 15.1±0.3 years. Speed time (50 m sprint was evaluated during sprint test, and anthropometric parameters were measured (weight, height, percent body fat. Correlation analysis (Pearson test was performed to evaluate the correlation between speed and anthropometrics. Results showed correlation between body weight and speed (r=-0.041 Sig=0.834; BMI values and speed (r=0.231; Sig=0.236, body height and speed (r=-0.384; Sig=0.044; percent body fat and speed (r=0.440; Sig=0.019.In conclusion, the results of this study show no significance association between body weight and BMI with sprint performance and significance correlation between body height (negative correlation and percent body fat (positive correlation with speed.

  19. The Influence of Serial Carbohydrate Mouth Rinsing on Power Output during a Cycle Sprint

    Directory of Open Access Journals (Sweden)

    Shaun M. Phillips, Scott Findlay, Mykolas Kavaliauskas, Marie Clare Grant

    2014-06-01

    Full Text Available The objective of the study was to investigate the influence of serial administration of a carbohydrate (CHO mouth rinse on performance, metabolic and perceptual responses during a cycle sprint. Twelve physically active males (mean (± SD age: 23.1 (3.0 years, height: 1.83 (0.07 m, body mass (BM: 86.3 (13.5 kg completed the following mouth rinse trials in a randomized, counterbalanced, double-blind fashion; 1. 8 x 5 second rinses with a 25 ml CHO (6% w/v maltodextrin solution, 2. 8 x 5 second rinses with a 25 ml placebo (PLA solution. Following mouth rinse administration, participants completed a 30 second sprint on a cycle ergometer against a 0.075 g·kg-1 BM resistance. Eight participants achieved a greater peak power output (PPO in the CHO trial, resulting in a significantly greater PPO compared with PLA (13.51 ± 2.19 vs. 13.20 ± 2.14 W·kg-1, p 0.05. No significant between-trials difference was reported for fatigue index, perceived exertion, arousal and nausea levels, or blood lactate and glucose concentrations. Serial administration of a CHO mouth rinse may significantly improve PPO during a cycle sprint. This improvement appears confined to the first 5 seconds of the sprint, and may come at a greater relative cost for the remainder of the sprint.

  20. Effects of a contrast training programme on jumping, sprinting and agility performance of prepubertal basketball players.

    Science.gov (United States)

    Latorre Román, Pedro Ángel; Villar Macias, Francisco Javier; García Pinillos, Felipe

    2018-04-01

    The purpose of this study was to examine the effects of a 10 week contrast training (CT) programme (isometric + plyometric) on jumping, sprinting abilities and agility performance in prepubertal basketball players. Fifty-eight children from a basketball academy (age: 8.72 ± 0.97 years; body mass index: 17.22 ± 2.48 kg/m 2 ) successfully completed the study. Participants were randomly assigned to experimental groups (EG, n = 30) and control groups (CG, n = 28). The CT programme was included in the experimental group's training sessions - twice a week - as part of their usual weekly training regime. This programme included 3 exercises: 1 isometric and 2 plyometric. Jumping, sprinting and agility performance were assessed before and after the training programme. Significant differences were found in posttest between EG and CG in sprint and T-test: EG showed better results than CG. Furthermore, there were significant differences in posttest-pretest between EG and CG in squat jump, countermovement jump, drop jump, sprint and T-test with the EG showing better results than CG. The CT programme led to increases in vertical jump, sprint and agility levels, so that the authors suggest that prepubertal children exhibit high muscular strength trainability.

  1. The Physiological Mechanisms of Performance Enhancement with Sprint Interval Training Differ between the Upper and Lower Extremities in Humans

    DEFF Research Database (Denmark)

    Zinner, Christoph; Morales-Alamo, David; Ørtenblad, Niels

    2016-01-01

    To elucidate the mechanisms underlying the differences in adaptation of arm and leg muscles to sprint training, over a period of 11 days 16 untrained men performed six sessions of 4-6 × 30-s all-out sprints (SIT) with the legs and arms, separately, with a 1-h interval of recovery. Limb-specific V...

  2. Sprint performance and propulsion asymmetries on an ergometer in trained high- and low-point wheelchair rugby players

    NARCIS (Netherlands)

    Goosey-Tolfrey, Victoria L; Vegter, Riemer J K; Mason, Barry S; Paulson, Thomas A W; Lenton, John P; van der Scheer, Jan W; van der Woude, Lucas H V

    The purpose of this study was to examine the propulsion asymmetries of wheelchair athletes while sprinting on an instrumented, dual-roller ergometer system. Eighteen experienced wheelchair rugby players (8 low point (LP) (class 1.5) and 10 high point (HP) (class 2.0)) performed a 15-second sprint in

  3. Can a 15m-overground wheelchair sprint be used to assess wheelchair-specific anaerobic work capacity?

    NARCIS (Netherlands)

    van der Scheer, Jan W.; de Groot, Sonja; Vegter, Riemer J. K.; Veeger, DirkJan (H. E. J. ); van der Woude, Lucas H. V.

    OBJECTIVE: To evaluate whether outcomes based on stopwatch time and power output (PO) over a 15m-overground wheelchair sprint test can be used to assess wheelchair-specific anaerobic work capacity, by studying their relationship with outcomes on a Wingate-based 30s-wheelchair ergometer sprint

  4. Can a 15m-overground wheelchair sprint be used to assess wheelchair-specific anaerobic work capacity?

    NARCIS (Netherlands)

    van der Scheer, J.W.; De Groot, S.; Vegter, R.J.K.; Veeger, H.E.J.; van der Woude, L.H.V.

    2014-01-01

    Objective: To evaluate whether outcomes based on stopwatch time and power output (PO) over a 15. m-overground wheelchair sprint test can be used to assess wheelchair-specific anaerobic work capacity, by studying their relationship with outcomes on a Wingate-based 30. s-wheelchair ergometer sprint

  5. The influence of ego depletion on sprint start performance in athletes without track and field experience.

    Science.gov (United States)

    Englert, Chris; Persaud, Brittany N; Oudejans, Raôul R D; Bertrams, Alex

    2015-01-01

    We tested the assumption that ego depletion would affect the sprint start in a sample of N = 38 athletes without track and field experience in an experiment by applying a mixed between- (depletion vs. non-depletion) within- (T1: before manipulation of ego depletion vs. T2: after manipulation of ego depletion) subjects design. We assumed that ego depletion would increase the possibility for a false start, as regulating the impulse to initiate the sprinting movement too soon before the starting signal requires self-control. In line with our assumption, we found a significant interaction as there was only a significant increase in the number of false starts from T1 to T2 for the depletion group while this was not the case for the non-depletion group. We conclude that ego depletion has a detrimental influence on the sprint start in athletes without track and field experience.

  6. Book Sprint: A new model for rapid book authoring and content development

    International Nuclear Information System (INIS)

    Zennaro, M.; Canessa, E.; Fonda, C.; Belcher, M.; Flickenger, R.

    2007-01-01

    We discuss our experiences and successes with the new 'Book Sprint' methodology for use in rapid authoring and content development for technical books and documentation, using a distributed team and appropriate on-line collaborative technologies. A sprint begins by assembling a group of domain experts for a short period of time-intensive content creation. The outline, scope, and approximate length of the book are established, and key contributors are identified. This is followed by remote and distributed work over a period of a few months, focussing on the bulk of the book. The Sprint Book methodology has already been used in the 'Wireless Networking in the Developing World' and 'Bandwidth Optimization and Management' books. Both of these are freely available under a Creative Commons License. (author)

  7. Lower limb joint kinetics and ankle joint stiffness in the sprint start push-off.

    Science.gov (United States)

    Charalambous, Laura; Irwin, Gareth; Bezodis, Ian N; Kerwin, David

    2012-01-01

    Sprint push-off technique is fundamental to sprint performance and joint stiffness has been identified as a performance-related variable during dynamic movements. However, joint stiffness for the push-off and its relationship with performance (times and velocities) has not been reported. The aim of this study was to quantify and explain lower limb net joint moments and mechanical powers, and ankle stiffness during the first stance phase of the push-off. One elite sprinter performed 10 maximal sprint starts. An automatic motion analysis system (CODA, 200 Hz) with synchronized force plates (Kistler, 1000 Hz) collected kinematic profiles at the hip, knee, and ankle and ground reaction forces, providing input for inverse dynamics analyses. The lower-limb joints predominately extended and revealed a proximal-to-distal sequential pattern of maximal extensor angular velocity and positive power production. Pearson correlations revealed relationships (P push-off in different ways, depending on the phase of stance considered.

  8. Sprint Start Kinetics of Amputee and Non-Amputee Sprinters

    Science.gov (United States)

    Willwacher, Steffen; Herrmann, Volker; Heinrich, Kai; Funken, Johannes; Strutzenberger, Gerda; Goldmann, Jan-Peter; Braunstein, Björn; Brazil, Adam; Irwin, Gareth; Potthast, Wolfgang; Brüggemann, Gert-Peter

    2016-01-01

    The purpose of this study was to explore the relationship between the forces applied to the starting blocks and the start performances (SPs) of amputee sprinters (ASs) and non-amputee sprinters (NASs). SPs of 154 male and female NASs (100-m personal records [PRs], 9.58–14.00 s) and 7 male ASs (3 unilateral above knee, 3 unilateral below knee, 1 bilateral below knee; 100 m PRs, 11.70–12.70 s) with running specific prostheses (RSPs) were analysed during full-effort sprint starts using instrumented starting blocks that measured the applied forces in 3D. Using the NAS dataset and a combination of factor analysis and multiple regression techniques, we explored the relationship between force characteristics and SP (quantified by normalized average horizontal block power). Start kinetics were subsequently compared between ASs and NASs who were matched based on their absolute 100 m PR and their 100 m PR relative to the world record in their starting class. In NASs, 86% of the variance in SP was shared with five latent factors on which measured parameters related to force application to the rear and front blocks and the respective push-off directions in the sagittal plane of motion were loaded. Mediolateral force application had little influence on SP. The SP of ASs was significantly reduced compared to that of NASs matched on the basis of relative 100-m PR (−33.8%; d = 2.11, p < 0.001), while a non-significant performance reduction was observed when absolute 100-m PRs were used (−17.7%; d = 0.79, p = 0.09). These results are at least partially explained by the fact that force application to the rear block was clearly impaired in the affected legs of ASs. PMID:27846241

  9. Sprint Start Kinetics of Amputee and Non-Amputee Sprinters.

    Directory of Open Access Journals (Sweden)

    Steffen Willwacher

    Full Text Available The purpose of this study was to explore the relationship between the forces applied to the starting blocks and the start performances (SPs of amputee sprinters (ASs and non-amputee sprinters (NASs. SPs of 154 male and female NASs (100-m personal records [PRs], 9.58-14.00 s and 7 male ASs (3 unilateral above knee, 3 unilateral below knee, 1 bilateral below knee; 100 m PRs, 11.70-12.70 s with running specific prostheses (RSPs were analysed during full-effort sprint starts using instrumented starting blocks that measured the applied forces in 3D. Using the NAS dataset and a combination of factor analysis and multiple regression techniques, we explored the relationship between force characteristics and SP (quantified by normalized average horizontal block power. Start kinetics were subsequently compared between ASs and NASs who were matched based on their absolute 100 m PR and their 100 m PR relative to the world record in their starting class. In NASs, 86% of the variance in SP was shared with five latent factors on which measured parameters related to force application to the rear and front blocks and the respective push-off directions in the sagittal plane of motion were loaded. Mediolateral force application had little influence on SP. The SP of ASs was significantly reduced compared to that of NASs matched on the basis of relative 100-m PR (-33.8%; d = 2.11, p < 0.001, while a non-significant performance reduction was observed when absolute 100-m PRs were used (-17.7%; d = 0.79, p = 0.09. These results are at least partially explained by the fact that force application to the rear block was clearly impaired in the affected legs of ASs.

  10. Energy compensation after sprint- and high-intensity interval training.

    Science.gov (United States)

    Schubert, Matthew M; Palumbo, Elyse; Seay, Rebekah F; Spain, Katie K; Clarke, Holly E

    2017-01-01

    Many individuals lose less weight than expected in response to exercise interventions when considering the increased energy expenditure of exercise (ExEE). This is due to energy compensation in response to ExEE, which may include increases in energy intake (EI) and decreases in non-exercise physical activity (NEPA). We examined the degree of energy compensation in healthy young men and women in response to interval training. Data were examined from a prior study in which 24 participants (mean age, BMI, & VO2max = 28 yrs, 27.7 kg•m-2, and 32 mL∙kg-1∙min-1) completed either 4 weeks of sprint-interval training or high-intensity interval training. Energy compensation was calculated from changes in body composition (air displacement plethysmography) and exercise energy expenditure was calculated from mean heart rate based on the heart rate-VO2 relationship. Differences between high (≥ 100%) and low (high levels of energy compensation gained fat mass, lost fat-free mass, and had lower change scores for VO2max and NEPA. Linear regression results indicated that lower levels of energy compensation were associated with increases in ΔVO2max (p interval training. In agreement with prior work, increases in ΔVO2max and ΔNEPA were associated with lower energy compensation. Future studies should focus on identifying if a dose-response relationship for energy compensation exists in response to interval training, and what underlying mechanisms and participant traits contribute to the large variation between individuals.

  11. The effect of sprinting after each set of heavy resistance training on the running speed and jumping performance of young basketball players.

    Science.gov (United States)

    Tsimahidis, Konstantinos; Galazoulas, Christos; Skoufas, Dimitrios; Papaiakovou, Georgios; Bassa, Eleni; Patikas, Dimitrios; Kotzamanidis, Christos

    2010-08-01

    The purpose of this study was to investigate the effect of a 10-week heavy resistance combined with a running training program on the strength, running speed (RS), and vertical jump performance of young basketball players. Twenty-six junior basketball players were equally divided in 2 groups. The control (CON) group performed only technical preparation and the group that followed the combined training program (CTP) performed additionally 5 sets of 8-5 repetition maximum (RM) half squat with 1 30-m sprint after each set. The evaluation took place before training and after the 5th and 10th weeks of training. Apart from the 1RM half squat test, the 10- and 30-m running time was measured using photocells and the jump height (squat, countermovement jump, and drop jump) was estimated taking into account the flight time. The 1RM increased by 30.3 +/- 1.5% at the 10th week of training for the CTP group (p 0.05). In general, all measured parameters showed a statistically significant increase after the 5th and 10th weeks (p 0.05). This suggests that the applied CTP is beneficial for the strength, RS, and jump height of young basketball players. The observed adaptations in the CTP group could be attributed to learning factors and to a more optimal transfer of the strength gain to running and jumping performance.

  12. 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.

  13. Baseline strength can influence the ability of salivary free testosterone to predict squat and sprinting performance.

    Science.gov (United States)

    Crewther, Blair T; Cook, Christian J; Gaviglio, Chris M; Kilduff, Liam P; Drawer, Scott

    2012-01-01

    The objective of this study was to determine if salivary free testosterone can predict an athlete's performance during back squats and sprints over time and the influence baseline strength on this relationship. Ten weight-trained male athletes were divided into 2 groups based on their 1 repetition maximum (1RM) squats, good squatters (1RM > 2.0 × body weight, n = 5) and average squatters (1RM squat 1RM and 10-m sprint times on 10 separate occasions over a 40-day period. A saliva sample was collected before testing and assayed for free testosterone and cortisol. The pooled testosterone correlations were strong and significant in the good squatters (r = 0.92 for squats, r = -0.87 for sprints, p squats, r = -0.18 for sprints). Cortisol showed no significant correlations with 1RM squat and 10-m sprint performance, and no differences were identified between the 2 squatting groups. In summary, these results suggest that free testosterone is a strong individual predictor of squat and sprinting performance in individuals with relatively high strength levels but a poor predictor in less strong individuals. This information can assist coaches, trainers, and performance scientists working with stronger weight-trained athletes, for example, the preworkout measurement of free testosterone could indicate likely training outcomes or a readiness to train at a certain intensity level, especially if real-time measurements are made. Our results also highlight the need to separate group and individual hormonal data during the repeated testing of athletes with variable strength levels.

  14. Relationship between traditional and ballistic squat exercise with vertical jumping and maximal sprinting.

    Science.gov (United States)

    Requena, Bernardo; García, Inmaculada; Requena, Francisco; de Villarreal, Eduardo Sáez-Sáez; Cronin, John B

    2011-08-01

    The purpose of this study was to quantify the magnitude of the relationship between vertical jumping and maximal sprinting at different distances with performance in the traditional and ballistic concentric squat exercise in well-trained sprinters. Twenty-one men performed 2 types of barbell squats (ballistic and traditional) across different loads with the aim of determining the maximal peak and average power outputs and 1 repetition maximum (1RM) values. Moreover, vertical jumping (countermovement jump test [CMJ]) and maximal sprints over 10, 20, 30, 40, 60, and 80 m were also assessed. In respect to 1RM in traditional squat, (a) no significant correlation was found with CMJ performance; (b) positive strong relationships (p ballistic and traditional squat exercises (r = 0.53-0.90); (c) negative significant correlations (r = -0.49 to -0.59, p ballistic or traditional squat exercises. Sprint time at 20 m was only related to ballistic and traditional squat performance when power values were expressed in relative terms. Moderate significant correlations (r = -0.39 to -0.56, p ballistic and traditional squat exercises. Sprint times at 60 and 80 m were mainly related to ballistic squat power outputs. Although correlations can only give insights into associations and not into cause and effect, from this investigation, it can be seen that traditional squat strength has little in common with CMJ performance and that relative 1RM and power outputs for both squat exercises are statistically correlated to most sprint distances underlying the importance of strength and power to sprinting.

  15. A comparison of assisted, resisted, and common plyometric training modes to enhance sprint and agility performance.

    Science.gov (United States)

    Khodaei, Kazem; Mohammadi, Abbas; Badri, Neda

    2017-10-01

    The purpose of this study was to compare the effect of assisted, resisted and common plyometric training modes to enhance sprint and agility performance. Thirty active young males (age 20.67±1.12, height 174.83±4.69, weight 63.45±7.51) volunteered to participate in this study that 24 completed testing. The participants were randomly assigned into different groups: assisted, resisted and common plyometric exercises groups. Plyometric training involved three sessions per week for 4 weeks. The volume load of plyometric training modes was equated between the groups. The posttest was performed after 48 hours of the last training session. Between-group differences were analyzed with the ANCOVA and LSD post-hoc tests, and within-group differences were analyzed by a paired t-test. The findings of the present study indicated that 0-10-m, 20-30-m sprint time and the Illinois Agility Test time significantly decreased in the assisted and resisted plyometrics modes compared to the common plyometric training mode (P≤0.05). Also, the 0-10-m, 0-30-m sprint time and agility T-test time was significantly reduced with resisted plyometrics modes compared to the assisted and common plyometric modes (P≤0.05). There was no significant difference in the 10-20-m sprint time among the three plyometric training modes. The results of this study demonstrated that assisted and resisted plyometrics modes with elastic bands were effective methods to improve sprint and agility performance than common plyometric training in active males. Also, the resisted plyometrics mode was superior than the assisted plyometrics mode to improving sprint and agility tasks.

  16. Kinetic Sprint Asymmetries on a non-motorised Treadmill in Rugby Union Athletes.

    Science.gov (United States)

    Brown, Scott R; Cross, Matt R; Girard, Olivier; Brocherie, Franck; Samozino, Pierre; Morin, Jean-Benoît

    2017-11-01

    The purpose of this study was to present a potential link between sprint kinetic (vertical [F V ] and horizontal force [F H ]) asymmetries and athletic performance during acceleration and maximal velocity (v max ) sprinting. Thirty un-injured male rugby athletes performed 8-s sprints on a non-motorised treadmill. Kinetic data were divided into 'strong' and 'weak' legs based on individually averaged peak values observed during sprinting and were analysed to evaluate asymmetry. Large differences were found between the strong and weak legs in F H during acceleration (4.3 vs. 3.5 N·kg -1 ) and v max (3.7 vs. 2.8 N·kg -1 ) sprinting (both ES=1.2), but not in F V (21.8 vs. 20.8 N·kg -1 , ES=- 0.6 for acceleration; 23.9 vs. 22.8 N·kg -1 , ES=- 0.5 for v max , respectively). Group mean asymmetry was lower in F V compared to F H during acceleration (1.6 vs. 6.8%) and v max (1.6 vs. 8.2%). The range of asymmetry was much lower in F V (0.03-4.3%) compared to F H (0.2-28%). In un-injured rugby athletes, the magnitude and range of asymmetry scores in F H , occurring during acceleration and v max phases, where much greater than those found in F V . These findings highlight the potential for some un-injured athletes to possess kinetic asymmetries known as crucial components for acceleration performance in sprinting. © Georg Thieme Verlag KG Stuttgart · New York.

  17. Sprint cycling performance is maintained with short-term contrast water immersion.

    Science.gov (United States)

    Crampton, David; Donne, Bernard; Egaña, Mikel; Egana, Mikel; Warmington, Stuart A

    2011-11-01

    Given the widespread use of water immersion during recovery from exercise, we aimed to investigate the effect of contrast water immersion on recovery of sprint cycling performance, HR and, blood lactate. Two groups completed high-intensity sprint exercise before and after a 30-min randomized recovery. The Wingate group (n = 8) performed 3 × 30-s Wingate tests (4-min rest periods). The repeated intermittent sprint group (n = 8) cycled for alternating 30-s periods at 40% of predetermined maximum power and 120% maximum power, until exhaustion. Both groups completed three trials using a different recovery treatment for each trial (balanced randomized application). Recovery treatments were passive rest, 1:1 contrast water immersion (2.5 min of cold (8°C) to 2.5 min of hot (40°C)), and 1:4 contrast water immersion (1 min of cold to 4 min of hot). Blood lactate and HR were recorded throughout, and peak power and total work for pre- and postrecovery Wingate performance and exercise time and total work for repeated sprinting were recorded. Recovery of Wingate peak power was 8% greater after 1:4 contrast water immersion than after passive rest, whereas both contrast water immersion ratios provided a greater recovery of exercise time (∼ 10%) and total work (∼ 14%) for repeated sprinting than for passive rest. Blood lactate was similar between trials. Compared with passive rest, HR initially declined more slowly during contrast water immersion but increased with each transition to a cold immersion phase. These data support contrast water immersion being effective in maintaining performance during a short-term recovery from sprint exercise. This effect needs further investigation but is likely explained by cardiovascular mechanisms, shown here by an elevation in HR upon each cold immersion.

  18. Low-Intensity Sprint Training With Blood Flow Restriction Improves 100-m Dash.

    Science.gov (United States)

    Behringer, Michael; Behlau, Daniel; Montag, Johannes C K; McCourt, Molly L; Mester, Joachim

    2017-09-01

    Behringer, M, Behlau, D, Montag, JCK, McCourt, ML, and Mester, J. Low-intensity sprint training with blood flow restriction improves 100-m dash. J Strength Cond Res 31(9): 2462-2472, 2017-We investigated the effects of practical blood flow restriction (pBFR) of leg muscles during sprint training on the 100-m dash time in well-trained sport students. Participants performed 6 × 100-m sprints at 60-70% of their maximal 100-m sprinting speed twice a week for 6 weeks, either with (intervention group [IG]; n = 12) or without pBFR (control group [CG]; n = 12). The 100-m dash time significantly decreased more in the IG (-0.38 ± 0.24 seconds) than in the CG (-0.16 ± 0.17 seconds). The muscle thickness of the rectus femoris increased only in the IG, whereas no group-by-time interactions were found for the muscle thickness of the biceps femoris and the biceps brachii. The maximal isometric force, measured using a leg press, did not change in either group. However, the rate of force development improved in the IG. Growth hormone, testosterone, insulin-like growth factor 1, and cortisol concentrations did not significantly differ between both groups at any measurement time point (pre, 1 minute, 20 minutes, 120 minutes, and 24 hours after the 6 all-out sprints of the first training session). The muscle damage marker h-FABP increased significantly more in the CG than in the IG. The pBFR improved the 100-m dash time significantly more than low-intensity sprint interval training alone. Other noted benefits of training with pBFR were a decreased level of muscle damage, a greater increase of the rectus femoris muscle thickness, and a higher rate of force development. However, the tested hormones were unable to explain the additional beneficial effects.

  19. Assessing the Personal Financial Problems of Junior Enlisted Personnel

    National Research Council Canada - National Science Library

    Buddin, Richard

    2002-01-01

    .... Surveys of military personnel show that, particularly for junior personnel, financial problems constitute a major source of stress, subordinate only to increased workload and family separation...

  20. Muscle and Blood Metabolites during a Soccer Game: Implications for Sprint Performance

    DEFF Research Database (Denmark)

    Krustrup, Peter; Mohr, Magni; Steensberg, Adam

    2006-01-01

    Abstract: Purpose: To examine muscle and blood metabolites during soccer match play and relate it to possible changes in sprint performance. Methods: Thirty-one Danish fourth division players took part in three friendly games. Blood samples were collected frequently during the game, and muscle......, muscle pH, or total glycogen content. Conclusion: Sprint performance is reduced both temporarily during a game and at the end of a soccer game. The latter finding may be explained by low glycogen levels in individual muscle fibers. Blood lactate is a poor indicator of muscle lactate during soccer match...

  1. The Influence of Serial Carbohydrate Mouth Rinsing on Power Output during a Cycle Sprint.

    Science.gov (United States)

    Phillips, Shaun M; Findlay, Scott; Kavaliauskas, Mykolas; Grant, Marie Clare

    2014-05-01

    The objective of the study was to investigate the influence of serial administration of a carbohydrate (CHO) mouth rinse on performance, metabolic and perceptual responses during a cycle sprint. Twelve physically active males (mean (± SD) age: 23.1 (3.0) years, height: 1.83 (0.07) m, body mass (BM): 86.3 (13.5) kg) completed the following mouth rinse trials in a randomized, counterbalanced, double-blind fashion; 1. 8 x 5 second rinses with a 25 ml CHO (6% w/v maltodextrin) solution, 2. 8 x 5 second rinses with a 25 ml placebo (PLA) solution. Following mouth rinse administration, participants completed a 30 second sprint on a cycle ergometer against a 0.075 g·kg(-1) BM resistance. Eight participants achieved a greater peak power output (PPO) in the CHO trial, resulting in a significantly greater PPO compared with PLA (13.51 ± 2.19 vs. 13.20 ± 2.14 W·kg(-1), p 0.05). No significant between-trials difference was reported for fatigue index, perceived exertion, arousal and nausea levels, or blood lactate and glucose concentrations. Serial administration of a CHO mouth rinse may significantly improve PPO during a cycle sprint. This improvement appears confined to the first 5 seconds of the sprint, and may come at a greater relative cost for the remainder of the sprint. Key pointsThe paper demonstrates that repeated administration of a carbohydrate mouth rinse can significantly improve peak power output during a single 30 second cycle sprint.The ergogenic effect of the carbohydrate mouth rinse may relate to the duration of exposure of the oral cavity to the mouth rinse, and associated greater stimulation of oral carbohydrate receptors.The significant increase in peak power output with the carbohydrate mouth rinse may come at a relative cost for the remainder of the sprint, evidenced by non-significantly lower mean power output and a greater fatigue index in the carbohydrate vs. placebo trial.Serial administration of a carbohydrate mouth rinse may be beneficial for

  2. Effects of Resisted Sprint Training and Traditional Power Training on Sprint, Jump, and Balance Performance in Healthy Young Adults: A Randomized Controlled Trial.

    Science.gov (United States)

    Prieske, Olaf; Krüger, Tom; Aehle, Markus; Bauer, Erik; Granacher, Urs

    2018-01-01

    Power training programs have proved to be effective in improving components of physical fitness such as speed. According to the concept of training specificity, it was postulated that exercises must attempt to closely mimic the demands of the respective activity. When transferring this idea to speed development, the purpose of the present study was to examine the effects of resisted sprint (RST) vs. traditional power training (TPT) on physical fitness in healthy young adults. Thirty-five healthy, physically active adults were randomly assigned to a RST ( n = 10, 23 ± 3 years), a TPT ( n = 9, 23 ± 3 years), or a passive control group ( n = 16, 23 ± 2 years). RST and TPT exercised for 6 weeks with three training sessions/week each lasting 45-60 min. RST comprised frontal and lateral sprint exercises using an expander system with increasing levels of resistance that was attached to a treadmill (h/p/cosmos). TPT included ballistic strength training at 40% of the one-repetition-maximum for the lower limbs (e.g., leg press, knee extensions). Before and after training, sprint (20-m sprint), change-of-direction speed (T-agility test), jump (drop, countermovement jump), and balance performances (Y balance test) were assessed. ANCOVA statistics revealed large main effects of group for 20-m sprint velocity and ground contact time (0.81 ≤ d ≤ 1.00). Post-hoc tests showed higher sprint velocity following RST and TPT (0.69 ≤ d ≤ 0.82) when compared to the control group, but no difference between RST and TPT. Pre-to-post changes amounted to 4.5% for RST [90%CI: (-1.1%;10.1%), d = 1.23] and 2.6% for TPT [90%CI: (0.4%;4.8%), d = 1.59]. Additionally, ground contact times during sprinting were shorter following RST and TPT (0.68 ≤ d ≤ 1.09) compared to the control group, but no difference between RST and TPT. Pre-to-post changes amounted to -6.3% for RST [90%CI: (-11.4%;-1.1%), d = 1.45) and -2.7% for TPT [90%CI: (-4.2%;-1.2%), d = 2.36]. Finally, effects for change

  3. Disorganized junior doctors fail the MRCP (UK).

    Science.gov (United States)

    Stanley, Adrian G; Khan, Khalid M; Hussain, Walayat; Tweed, Michael

    2006-02-01

    Career progression during undergraduate and early postgraduate years is currently determined by successfully passing examinations. Both academic factors (secondary school examination results, learning style and training opportunities) and non-academic factors (maturity, ethnic origin, gender and motivation) have been identified as predicting examination outcome. Few studies have examined organization skills. Disorganized medical students are more likely to perform poorly in end-of-year examinations but this observation has not been examined in junior doctors. This study asked whether organization skills relate to examination outcome amongst junior doctors taking the clinical Part II examination for the Membership of the Royal College of Physicians (Practical Assessment of Clinical Examination Skills). The study was conducted prospectively at four consecutive clinical courses that provided clinical teaching and practice to prepare trainees for the examination. Arrival time at registration for the course was the chosen surrogate for organization skills. Trainees were advised that they should arrive promptly at 8.00 a.m. for registration and it was explained that the course would start at 8.30 a.m. Recorded arrival times were compared with the pass lists published by the Royal College of Physicians. The mean arrival time was 8.17 a.m. A total of 81 doctors (53.3%) passed the examination with a mean arrival time of 8.14 a.m. However, 71 doctors failed the exam and arrived, on average, six minutes later than doctors who passed (p?=?0.006). Better-prepared junior doctors were more likely to pass the final examination. Arriving on time represents a composite of several skills involved in the planning of appropriate travel arrangements and is therefore a valid marker of organization skills and preparation. This novel study has shown that good time-keeping skills are positively associated with examination outcome.

  4. Increases in lower-body strength transfer positively to sprint performance: a systematic review with meta-analysis.

    Science.gov (United States)

    Seitz, Laurent B; Reyes, Alvaro; Tran, Tai T; Saez de Villarreal, Eduardo; Haff, G Gregory

    2014-12-01

    Although lower-body strength is correlated with sprint performance, whether increases in lower-body strength transfer positively to sprint performance remain unclear. This meta-analysis determined whether increases in lower-body strength (measured with the free-weight back squat exercise) transfer positively to sprint performance, and identified the effects of various subject characteristics and resistance-training variables on the magnitude of sprint improvement. A computerized search was conducted in ADONIS, ERIC, SPORTDiscus, EBSCOhost, Google Scholar, MEDLINE and PubMed databases, and references of original studies and reviews were searched for further relevant studies. The analysis comprised 510 subjects and 85 effect sizes (ESs), nested with 26 experimental and 11 control groups and 15 studies. There is a transfer between increases in lower-body strength and sprint performance as indicated by a very large significant correlation (r = -0.77; p = 0.0001) between squat strength ES and sprint ES. Additionally, the magnitude of sprint improvement is affected by the level of practice (p = 0.03) and body mass (r = 0.35; p = 0.011) of the subject, the frequency of resistance-training sessions per week (r = 0.50; p = 0.001) and the rest interval between sets of resistance-training exercises (r = -0.47; p ≤ 0.001). Conversely, the magnitude of sprint improvement is not affected by the athlete's age (p = 0.86) and height (p = 0.08), the resistance-training methods used through the training intervention, (p = 0.06), average load intensity [% of 1 repetition maximum (RM)] used during the resistance-training sessions (p = 0.34), training program duration (p = 0.16), number of exercises per session (p = 0.16), number of sets per exercise (p = 0.06) and number of repetitions per set (p = 0.48). Increases in lower-body strength transfer positively to sprint performance. The magnitude of sprint improvement is affected by numerous subject characteristics and resistance

  5. Validation of the short posttraumatic stress disorder rating interview (SPRINT-E in a sample of people affected by F-27 Chilean earthquake and tsunami

    Directory of Open Access Journals (Sweden)

    Marcelo C. Leiva-Bianchi

    2013-05-01

    Full Text Available On February 27, 2010 (F-27 there was an earthquake and a tsunami m Chile that has caused a great impact on the mental health of the population of this country, specifically in the increase of cases of posttraumatic stress disorder (PTSD. In view of count better instruments to measure PTSD was applied for the first time since it was created, the SPRINTE scale in a population other than the U.S., specifically in 291 people who experienced the F-27. The analysis of reliability (α=. 916, concurrent validity (all items significantly correlated with the scale used as a criterion DTS and construct validity (CMIN=2.237, RMSEA=.092, NFI=.901, CFI=.942 and PNFI=.704 for two-factor model indicate that SPRINT-E is a valid and reliable scale to measure PTSD in this population. Finally, some reflections about new factor structure discovered in this analysis, which is consistent with the meaning of items and with theoretical models such as covert stimuli. It also reflects on the usefulness of a brief scale, proven valid and very good psychometric characteristics in a Spanish-speaking population prone to natural disasters such as Chilean F-27, Japan (March 11, 2011 or Spain (May 11, 2011.

  6. Energy compensation after sprint- and high-intensity interval training.

    Directory of Open Access Journals (Sweden)

    Matthew M Schubert

    Full Text Available Many individuals lose less weight than expected in response to exercise interventions when considering the increased energy expenditure of exercise (ExEE. This is due to energy compensation in response to ExEE, which may include increases in energy intake (EI and decreases in non-exercise physical activity (NEPA. We examined the degree of energy compensation in healthy young men and women in response to interval training.Data were examined from a prior study in which 24 participants (mean age, BMI, & VO2max = 28 yrs, 27.7 kg•m-2, and 32 mL∙kg-1∙min-1 completed either 4 weeks of sprint-interval training or high-intensity interval training. Energy compensation was calculated from changes in body composition (air displacement plethysmography and exercise energy expenditure was calculated from mean heart rate based on the heart rate-VO2 relationship. Differences between high (≥ 100% and low (< 100% levels of energy compensation were assessed. Linear regressions were utilized to determine associations between energy compensation and ΔVO2max, ΔEI, ΔNEPA, and Δresting metabolic rate.Very large individual differences in energy compensation were noted. In comparison to individuals with low levels of compensation, individuals with high levels of energy compensation gained fat mass, lost fat-free mass, and had lower change scores for VO2max and NEPA. Linear regression results indicated that lower levels of energy compensation were associated with increases in ΔVO2max (p < 0.001 and ΔNEPA (p < 0.001.Considerable variation exists in response to short-term, low dose interval training. In agreement with prior work, increases in ΔVO2max and ΔNEPA were associated with lower energy compensation. Future studies should focus on identifying if a dose-response relationship for energy compensation exists in response to interval training, and what underlying mechanisms and participant traits contribute to the large variation between individuals.

  7. To Assess Sleep Quality among Pakistani Junior Physicians (House ...

    African Journals Online (AJOL)

    Background: Sleep deprivation among junior physicians (house officers) is of growing concern. In developed countries, duty hours are now mandated, but in developing countries, junior physicians are highly susceptible to develop sleep impairment due to long working hours, on‑call duties and shift work schedule. Aim: We ...

  8. Poor interpretation of chest X-rays by junior doctors

    DEFF Research Database (Denmark)

    Christiansen, Janus Mølgaard; Gerke, Oke; Karstoft, Jens

    2014-01-01

    INTRODUCTION: Studies targeting medical students and junior doctors have shown that their radiological skills are insufficient. Despite the widespread use of chest X-ray; however, a study of Danish junior doctors' skills has not previously been performed. MATERIAL AND METHODS: A total of 22...

  9. Multiple Intelligences Profiles of Junior Secondary School Students in Indonesia

    Science.gov (United States)

    Emmiyati, Nuri; Rasyid, Muhammad Amin; Rahman, M. Asfah; Arsyad, Azhar; Dirawan, Gufran Darma

    2014-01-01

    This study aimed to investigate the Multiple Intelligences profiles of the students at junior secondary school in Makassar. The Multiple Intelligences Inventory was used to identify the dominant intelligence among the students. The sample of this research was 302 junior secondary schools students in Makassar Indonesia who willing to participated…

  10. Parental Resources and the Transition to Junior High.

    Science.gov (United States)

    Grolnick, Wendy S.; Kurowski, Carolyn O.; Dunlap, Kelly G.; Hevey, Cheryl

    2000-01-01

    This study examined whether maternal resources of involvement and autonomy support might buffer children against the negative effects of the transition to junior high. School, cognitive, and personal involvement were examined. Findings highlight the importance of the home environment in children's coping with the transition to junior high.…

  11. Theorizing Food Sharing Practices in a Junior High Classroom

    Science.gov (United States)

    Rice, Mary

    2013-01-01

    This reflective essay analyzes interactions where food was shared between a teacher and her junior high school students. The author describes the official uses of food in junior high school classrooms and in educational contexts in general. The author then theorizes these interactions, suggesting other semiotic, dialogic, and culturally encoded…

  12. Attitude of Junior Secondary School Students towards the Study of ...

    African Journals Online (AJOL)

    of girls' education in Science subjects, as it exists in Ghana with reference to J.S.S. pupils' attitude to Science. Using a stratified random sample of junior secondary school students from public and private schools, the study investigated the attitudes of junior secondary school students towards the study of science. Data were ...

  13. Potential benefits of student- and junior doctor-led textbooks.

    Science.gov (United States)

    Qureshi, Zeshan U; Lattey, Katherine; Bryne, Patrick; Rodrigues, Mark; Ross, Michael; Maxwell, Simon

    2015-06-01

    Medical textbooks are an important teaching supplement. Few have junior doctors or medical students ('juniors') as primary contributors. However, the strengths of junior-led face-to-face teaching are now well-established, and we hypothesized that similar advantages would be transferrable to a textbook setting. Juniors were approached to contribute to an independently published medical textbook, with senior clinicians recruited in parallel to ensure factual accuracy. Juniors directed every aspect of textbook writing and the production process. The published book stressed that it was an open collaboration with readers, inviting them to get in touch to evaluate the text and suggest ideas for new titles. Of 75 respondents, 93 % awarded the first textbook in the series 4 or 5 out of 5 for overall quality. Five other titles have been released, with seven more in development. Over 100 juniors are currently involved, with two students progressing from reviewers to editors after less than a year of mentorship. Juniors can be a motivated, dynamic, innovative group, capable of significant contributions to the medical textbook literature. This initiative has generated a sustainable infrastructure to facilitate junior-led publishing, and has the capacity for expansion to accommodate new initiatives and ideas.

  14. Professional Training of Junior Medical Staff: European Experience

    Science.gov (United States)

    Iliasova, Yuliia

    2017-01-01

    The article covers current problems of professional training of junior medical staff. The main disadvantages of Ukrainian system of medical education that impede the intention of improving quality of professional training of junior medical staff have been analyzed. European experience in organizing medical education, namely, in Great Britain,…

  15. Sexuality Education in Junior High Schools in Japan

    Science.gov (United States)

    Hashimoto, N.; Shinohara, H.; Tashiro, M.; Suzuki, S.; Hirose, H.; Ikeya, H.; Ushitora, K.; Komiya, A.; Watanabe, M.; Motegi, T.; Morioka, M.

    2012-01-01

    This paper aims to determine via responses to three questionnaire surveys how sexuality education programs are conducted at junior high schools in Japan. Study 1 examined the practice of sexuality education in schools, Study 2 investigated junior high school students' (age 12-13 and 14-15 years) knowledge of sexuality, and Study 3 examined…

  16. Comparison of Sprint Reaction and Visual Reaction Times of Athletes in Different Branches

    Science.gov (United States)

    Akyüz, Murat; Uzaldi, Basar Basri; Akyüz, Öznur; Dogru, Yeliz

    2017-01-01

    The aims of this study are to analyse sprint reaction and visual reaction times of female athletes of different branches competing in Professional leagues and to show the differences between them. 42 voluntary female athletes from various branches of Professional leagues of Istanbul (volleyball, basketball, handball) were included in the…

  17. Autonomic modulations of heart rate variability are associated with sports injury incidence in sprint swimmers.

    Science.gov (United States)

    Lima-Borges, Dayanne S; Martinez, Paula F; Vanderlei, Luiz Carlos M; Barbosa, Fernando S S; Oliveira-Junior, Silvio A

    2018-03-28

    Young athletes' participation in competitive sports is becoming increasingly common, and this increased involvement raises concerns about the occurrence of overtraining and sports injuries. Since these issues are poorly understood, this study analyzed heart rate variability, stress/recovery relationship, and sports injury incidence during a training macrocycle of young sprint and endurance swimmers. Thirty teenage swimmers (aged 12 to 17 years) were divided into two groups as follows: Sprint (n = 17) and Endurance (n = 13). Subjects were evaluated over 20 weeks, based on the following three schedules: general, specific, and competitive. In addition to heart rate variability and sports injury incidence, the Recovery-Stress-Questionnaire of Athletes was used to analyse stress/recovery states in athletes. All procedures were developed at the initial moment and at the end of each periodization step. The Sprint group presented a reduced standard deviation of normal-normal beats (73.0 ± 6.6 vs. 54.1 ± 3.5 ms; p sports injury than the Endurance group (0.0214 ± 0.0068 vs. 0.0136 ± 0.0050 cases/1000 hours). Sprint training was associated with progressive activation of the sympathetic nervous system as well as a higher incidence of sports injury in comparison to endurance swimming during a training macrocycle.

  18. Effect of ischemic preconditioning on land-based sprinting in team-sport athletes.

    Science.gov (United States)

    Gibson, Neil; White, James; Neish, Mhari; Murray, Andrew

    2013-11-01

    The study aimed to assess whether exposure to ischemic preconditioning (IPC) in a trained population would affect land-based maximal sprinting performance over 30 m. Twenty-five well-trained participants regularly involved in invasion-type team-sport events were recruited to take part in a randomized crossover study design. Participants underwent both an IPC and a placebo treatment involving 3 periods of 5-min occlusion applied unilaterally (3 × 5-min occlusion to each leg) at either 220 mmHg or 50 mmHg, respectively. Each period of occlusion was followed by 5 min of reperfusion. After treatment, 3 maximal sprints over a distance of 30 m were undertaken from a standing start interspersed with 1-min recovery. Split times were recorded at 10, 20, and 30 m. No significant effects of the IPC treatment were observed on sprint speed (P split timings; however, a small and negative effect was observed in female participants. Calculated effect sizes of the treatment were found to be trivial (swimming, further research is required to elucidate whether this is the case over distances associated with land-based events in track and field or in events reliant on repeated-sprint ability.

  19. Estimation of tensile force in the hamstring muscles during overground sprinting.

    Science.gov (United States)

    Ono, T; Higashihara, A; Shinohara, J; Hirose, N; Fukubayashi, T

    2015-02-01

    The purpose of this study was to identify the period of the gait cycle during which the hamstring muscles were likely injured by estimating the magnitude of tensile force in each muscle during overground sprinting. We conducted three-dimensional motion analysis of 12 male athletes performing overground sprinting at their maximal speed and calculated the hamstring muscle-tendon length and joint angles of the right limb throughout a gait cycle during which the ground reaction force was measured. Electromyographic activity during sprinting was recorded for the biceps femoris long head, semitendinosus, and semimembranosus muscles of ipsilateral limb. We estimated the magnitude of tensile force in each muscle by using the length change occurred in the musculotendon and normalized electromyographic activity value. The study found a quick increase of estimated tensile force in the biceps femoris long head during the early stance phase of the gait cycle during which the increased hip flexion angle and ground reaction force occurred at the same time. This study provides quantitative data of tensile force in the hamstring muscles suggesting that the biceps femoris long head muscle is susceptible to a strain injury during the early stance phase of the sprinting gait cycle. © Georg Thieme Verlag KG Stuttgart · New York.

  20. Improvement of Ice Hockey Players' On-Ice Sprint With Combined Plyometric and Strength Training.

    Science.gov (United States)

    Dæhlin, Torstein E; Haugen, Ole C; Haugerud, Simen; Hollan, Ivana; Raastad, Truls; Rønnestad, Bent R

    2017-08-01

    Combined plyometric and strength training has previously been suggested as a strategy to improve skating performance in ice hockey players. However, the effects of combined plyometric and strength training have not previously been compared with the effects of strength training only. To compare the effects of combined plyometric and strength training on ice hockey players' skating sprint performance with those of strength training only. Eighteen participants were randomly assigned to 2 groups that completed 5 strength-training sessions/wk for 8 wk. One group included plyometric exercises at the start of 3 sessions/wk (PLY+ST), and the other group included core exercises in the same sessions (ST). Tests of 10- and 35-m skating sprints, horizontal jumping, 1-repetition-maximum (1 RM) squat, skating multistage aerobic test (SMAT), maximal oxygen consumption, repeated cycle sprints, and body composition were performed before and after the intervention. The participants increased their 1RM squat, lean mass, and body mass (P plyometric and strength training for 8 wk was superior to strength training alone at improving 10-m on-ice sprint performance in high-level ice hockey players.

  1. Comparison of muscle strength, sprint power and aerobic capacity in adults with and without cerebral palsy

    NARCIS (Netherlands)

    de Groot, Sonja; Dallmeijer, Annet J.; Bessems, Paul J. C.; Lamberts, Marcel L.; van der Woude, Lucas H. V.; Janssen, Thomas W. J.

    Objective: To compare: (i) muscle strength, sprint power and maximal aerobic capacity; and (ii) the correlations between these variables in adults with and without cerebral palsy. Design: Cross-sectional study. Subjects: Twenty adults with and 24 without cerebral palsy. Methods: Isometric and

  2. The Effect of Gender on Sprint Performance of 10-13 Aged Middle School Students

    Directory of Open Access Journals (Sweden)

    Serhat Turan

    2016-04-01

    Full Text Available The aim of the study was to investigate the effect of gender on the 30 m sprint performance of middle school students (10-13 ages. The study included 25 male and 25 female total 50 middle school students. The mean age of female students was found as 12,36 ± 0,48 (year, the mean body weight as 42,03 ± 3,63 (kg, and the mean height as 151,11 ±5,61 (cm, and the mean age of male students was found as 12,28 ± 0,45 (year, the mean height as 152,28 ± 5,04 (cm, and the mean body weight as 43,35 ± 1,88 (kg. The mean sprint performance of female students was calculated as 6,33 ± 0,53 seconds, and the mean sprint performance of the male students was 6,17 ± 0,47 seconds. As a result the effect of gender on sprint performance was found to be insignificant between the groups (p>0,05.

  3. Comparison of muscle strength, sprint power and aerobic capacity in adults with and without cerebral palsy

    NARCIS (Netherlands)

    de Groot, S.; Dallmeijer, A.J.; Bessems, P.J.C.; Lamberts, M.L.; van der Woude, L.H.V.; Janssen, T.W.J.

    2012-01-01

    Objective: To compare: (i) muscle strength, sprint power and maximal aerobic capacity; and (ii) the correlations between these variables in adults with and without cerebral palsy. Design: Cross-sectional study. Subjects: Twenty adults with and 24 without cerebral palsy. Methods: Isometric and

  4. A Modified T-Test for Football Referees to Test Agility, Quickness and Sprint Performances

    Science.gov (United States)

    Muniroglu, S.; Subak, E.

    2018-01-01

    The football referees perform many actions as jogging, running, sprinting, side steps and backward steps during a football match. Further, the football referees change match activities every 5-6 seconds. Many tests are being conducted to determine the physical levels and competences of football referees like 50 m running, 200 m running, 12 minutes…

  5. Short- or long-rest intervals during repeated-sprint training in soccer?

    Science.gov (United States)

    Iaia, F. Marcello; Fiorenza, Matteo; Larghi, Luca; Alberti, Giampietro; Millet, Grégoire P.; Girard, Olivier

    2017-01-01

    The present study compared the effects of two repeated-sprint training (RST) programs, differing in duration of the between-sprint rest intervals, on various soccer-related exercise performances. For 5 weeks during the competitive season, twenty-nine young trained male soccer players either replaced two of their habitual fitness conditioning sessions with RST characterized by short (5–15; n = 9) or long (5–30; n = 10) rest intervals, or served as control (n = 10). The 5–15 and 5–30 protocols consisted of 6 repetitions of 30-m (~5 s) straight-line sprints interspersed with 15 s or 30 s of passive recovery, respectively. 5–15 improved 200-m sprint time (2.0±1.5%; pRecovery Test Level 2 increased following 5–15 (11.4±5.0%; psoccer players, RST over a 5-week in-season period is an efficient means to simultaneously develop different components of fitness relevant to match performance, with different benefits induced by shorter compared to longer rest intervals. PMID:28199402

  6. Jumping and Hopping in Elite and Amateur Orienteering Athletes and Correlations to Sprinting and Running

    DEFF Research Database (Denmark)

    Hébert-Losier, Kim; Jensen, Kurt; Holmberg, Hans-Christer

    2014-01-01

    PURPOSE: Jumping and hopping are used to measure lower-body muscle power, stiffness, and stretch-shortening cycle utilization in sports, with several studies reporting correlations between such measures and sprinting and/or running abilities in athletes. Neither jumping and hopping nor correlatio...... and rapid generation of high relative maximal forces, especially vertically. These functional measures were more closely related to sprinting and/or running abilities, indicating benefits of lower-body training in orienteering.......PURPOSE: Jumping and hopping are used to measure lower-body muscle power, stiffness, and stretch-shortening cycle utilization in sports, with several studies reporting correlations between such measures and sprinting and/or running abilities in athletes. Neither jumping and hopping nor correlations...... with sprinting and/or running have been examined in orienteering athletes. METHODS: We investigated squat jump (SJ), countermovement jump (CMJ), standing long jump (SLJ), and hopping performed by 8 elite and 8 amateur male foot-orienteering athletes (29 ± 7 y, 183 ± 5 cm, 73 ± 7 kg) and possible correlations...

  7. Isometric strength, sprint power, and aerobic power in individuals with a spinal cord injury

    NARCIS (Netherlands)

    Janssen, T W; van Oers, C A; Hollander, A P; Veeger, DirkJan (H. E. J.); van der Woude, L H

    This study investigated in rather specific wheelchair tests the relationships among estimates of isometric upper-body strength (Fiso), sprint power (P30), aerobic power (VO2peak), and maximal power output (POaer) in a group of 44 men (age 34 +/- 12 yr) with longstanding spinal cord injuries ranging

  8. The effect of a sport development programme on sprinting and long ...

    African Journals Online (AJOL)

    The talented children in both groups then underwent a specific test battery designed for sprinting and long jump. Maturity was determined by means of a maturity questionnaire. The development programme contributed statistically significant to the improvement in flexibility, muscle endurance, 0-40 meter speed and ...

  9. Sprinting on a running track: a rare cause of a Lisfranc dislocation.

    LENUS (Irish Health Repository)

    Khan, F

    2012-02-03

    We present a case report of a young man who sustained a serious foot injury while sprinting in a straight line. We discuss the management of these injuries and emphasise the importance of a high index of suspicion amongst orthopaedic, casualty and radiology trainees.

  10. Effects of the Nordic Hamstring exercise on sprint capacity in male football players

    DEFF Research Database (Denmark)

    Ishøi, Lasse; Hölmich, Per; Aagaard, Per

    2018-01-01

    This assessor-blinded, randomized controlled superiority trial investigated the efficacy of the 10-week Nordic Hamstring exercise (NHE) protocol on sprint performance in football players. Thirty-five amateur male players (age: 17-26 years) were randomized to a do-as-usual control group (CG; n = 1...

  11. Establishing a Practical Treadmill Sprint as an Alternative to the Wingate Anaerobic Test

    Science.gov (United States)

    McKie, Greg L.; Islam, Hashim; Townsend, Logan K.; Howe, Greg J.; Hazell, Tom J.

    2018-01-01

    This study examined the validity and reliability of a 30-second running sprint test using two non-motorized treadmills compared to the established Wingate Anaerobic Test. Twenty-four participants completed three sessions in a randomized order on a: (1) manual mode treadmill (Woodway); (2) specialized interval training treadmill (HiTrainer); and…

  12. Shuttle-Run Sprint Training in Hypoxia for Youth Elite Soccer Players: A Pilot Study

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    Hannes Gatterer

    2014-12-01

    Full Text Available The purposes of the present study were to investigate if a shuttle-run sprint training performed in a normobaric hypoxia chamber of limited size (4.75x2.25m is feasible, in terms of producing the same absolute training load, when compared to training in normoxia, and b if such training improves the repeated sprint ability (RSA and the Yo-Yo intermittent recovery (YYIR test outcome in young elite soccer players. Players of an elite soccer training Centre (age: 15.3 ± 0.5 years, height: 1.73 ± 0.07 m, body mass: 62.6 ± 6.6 kg were randomly assigned to a hypoxia or a normoxia training group. Within a 5-week period, players, who were not informed about the hypoxia intervention, performed at least 7 sessions of identical shuttle-run sprint training either in a normal training room (FiO2 = 20.95% or in a hypoxic chamber (FiO2 = 14.8%; approximately 3300m, both equipped with the same floor. Each training session comprised 3 series of 5x10s back and forth sprints (4.5m performed at maximal intensity. Recovery time between repetitions was 20s and between series 5min. Before and after the training period the RSA (6 x 40m shuttle sprint with 20 s rest between shuttles and the YYIR test were performed. The size of the chamber did not restrict the training intensity of the sprint training (both groups performed approximately 8 shuttles during 10s. Training in hypoxia resulted in a lower fatigue slope which indicates better running speed maintenance during the RSA test (p = 0.024. YYIR performance increased over time (p = 0.045 without differences between groups (p > 0.05. This study showed that training intensity of the shuttle-run sprint training was not restricted in a hypoxic chamber of limited size which indicates that such training is feasible. Furthermore, hypoxia compared to normoxia training reduced the fatigue slope during the RSA test in youth soccer players.

  13. JUMP KINETIC DETERMINANTS OF SPRINT ACCELERATION PERFORMANCE FROM STARTING BLOCKS IN MALE SPRINTERS

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    Peter S. Maulder

    2006-06-01

    Full Text Available The purpose of this research was to identify the jump kinetic determinants of sprint acceleration performance from a block start. Ten male (mean ± SD: age 20 ± 3 years; height 1.82 ± 0.06 m; weight 76.7 ± 7.9 kg; 100 m personal best: 10.87 + 0.36 s {10.37 - 11.42} track sprinters at a national and regional competitive level performed 10 m sprints from a block start. Anthropometric dimensions along with squat jump (SJ, countermovement jump (CMJ, continuous straight legged jump (SLJ, single leg hop for distance, and single leg triple hop for distance measures of power were also tested. Stepwise multiple regression analysis identified CMJ average power (W/kg as a predictor of 10 m sprint performance from a block start (r = 0.79, r2 = 0.63, p<0.01, SEE = 0.04 (s, %SEE = 2.0. Pearson correlation analysis revealed CMJ force and power (r = -0.70 to -0.79; p = 0.011 - 0.035 and SJ power (r = -0.72 to -0.73; p = 0.026 - 0.028 generating capabilities to be strongly related to sprint performance. Further linear regression analysis predicted an increase in CMJ average and peak take-off power of 1 W/kg (3% & 1.5% respectively to both result in a decrease of 0.01 s (0.5% in 10 m sprint performance. Further, an increase in SJ average and peak take-off power of 1 W/kg (3.5% & 1.5% respectively was predicted to result in a 0.01 s (0.5% reduction in 10 m sprint time. The results of this study seem to suggest that the ability to generate power both elastically during a CMJ and concentrically during a SJ to be good indicators of predicting sprint performance over 10 m from a block start

  14. Sprint profile of professional female soccer players during competitive matches: Female Athletes in Motion (FAiM) study.

    Science.gov (United States)

    Vescovi, Jason D

    2012-01-01

    The aim of this study was to determine sprint profiles of professional female soccer players and evaluate how various speed thresholds impact those outcomes. Seventy-one professional players competing in full matches were assessed repeatedly during 12 regular season matches using a Global Positioning System (GPS). Locomotion ≥18 km · h⁻¹ was defined as sprinting and each event was classified into: Zone 1: 18.0-20.9 km· h⁻¹; Zone 2: 21.0-22.9 km · h⁻¹; Zone 3: 23.0-24.9 km · h⁻¹ and Zone 4: >25 km · h⁻¹. Outcomes included: duration (s), distance (m), maximum speed (km · h⁻¹), duration since previous sprint (min) and proportion of total sprint distance. In total 5,019 events were analysed from 139 player-matches. Mean sprint duration, distance, maximum speed and time between sprints were 2.3 ± 1.5 s, 15.1 ± 9.4 m, 21.8 ± 2.3 km· h⁻¹, and 2.5 ± 2.5 min, respectively. Mean sprint distances were 657 ± 157, 447 ± 185, and 545 ± 217 m for forwards, midfielders and defenders, respectively (P ≤ 0.046). Midfielders had shorter sprint duration (P = 0.023), distance (P ≤ 0.003) and maximum speed (P professional female soccer players covered 5.3 ± 2.0% of total distance ≥18 km · h⁻¹ with positional differences and percent decrements distinct from other previously identified elite players. These data should guide the development of high intensity and sprint thresholds for elite-standard female soccer players.

  15. Effects of Sled Towing on Peak Force, the Rate of Force Development and Sprint Performance During the Acceleration Phase

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    Martínez-Valencia María Asunción

    2015-06-01

    Full Text Available Resisted sprint training is believed to increase strength specific to sprinting. Therefore, the knowledge of force output in these tasks is essential. The aim of this study was to analyze the effect of sled towing (10%, 15% and 20% of body mass (Bm on sprint performance and force production during the acceleration phase. Twenty-three young experienced sprinters (17 men and 6 women; men = 17.9 ± 3.3 years, 1.79 ± 0.06 m and 69.4 ± 6.1 kg; women = 17.2 ± 1.7 years, 1.65 ± 0.04 m and 56.6 ± 2.3 kg performed four 30 m sprints from a crouch start. Sprint times in 20 and 30 m sprint, peak force (Fpeak, a peak rate of force development (RFDpeak and time to RFD (TRFD in first step were recorded. Repeated-measures ANOVA showed significant increases (p ≤ 0.001 in sprint times (20 and 30 m sprint for each resisted condition as compared to the unloaded condition. The RFDpeak increased significantly when a load increased (3129.4 ± 894.6 N·s−1, p ≤ 0.05 and 3892.4 ± 1377.9 N·s−1, p ≤ 0.01. Otherwise, no significant increases were found in Fpeak and TRFD. The RFD determines the force that can be generated in the early phase of muscle contraction, and it has been considered a factor that influences performance of force-velocity tasks. The use of a load up to 20% Bm might provide a training stimulus in young sprinters to improve the RFDpeak during the sprint start, and thus, early acceleration.

  16. Three Days of Intermittent Fasting: Repeated-Sprint Performance Decreased by Vertical-Stiffness Impairment.

    Science.gov (United States)

    Cherif, Anissa; Meeusen, Romain; Farooq, Abdulaziz; Ryu, Joong; Fenneni, Mohamed Amine; Nikolovski, Zoran; Elshafie, Sittana; Chamari, Karim; Roelands, Bart

    2017-03-01

    To examine the effects of 3 d of intermittent fasting (3d-IF: abstaining from eating/drinking from dawn to sunset) on physical performance and metabolic responses to repeated sprints (RSs). Twenty-one active males performed an RS test (2 sets: 5 × 5-s maximal sprints with 25 s of recovery between and 3 min of recovery between sets on an instrumented treadmill) in 2 conditions: counterbalanced fed/control session (CS) and fasting session (FS). Biomechanical and biochemical markers were assessed preexercise and postexercise. Significant main effects of IF were observed for sprints: maximal speed (P = .016), mean speed (P = .015), maximal power (P = .035), mean power (P = .049), vertical stiffness (P = .032), and vertical center-of-mass displacement (P = .047). Sprint speed and vertical stiffness decreased during the 1st (P = .003 and P = .005) and 2nd sprints (P = .046 and P = .048) of set 2, respectively. Postexercise insulin decreased in CS (P = .023) but not in FS (P = .230). Free-fatty-acid levels were higher in FS than in CS at preexercise (P < .001) and at postexercise (P = .009). High-density lipoprotein cholesterol (HDL-C) was higher at postexercise in FS (1.32 ± 0.22 mmol/L) than in CS (1.26 ± 0.21 mmol/L, P = .039). The triglyceride (TG) concentration was decreased in FS (P < .05) compared with CS. 3d-IF impaired speed and power through a decrease in vertical stiffness during the initial runs of the 2nd set of RS. The findings of the current study confirmed the benefits of 3d-IF: improved HDL-C and TG profiles while maintaining total cholesterol and low-density lipoprotein cholesterol levels. Moreover, improving muscle power might be a key factor to retain a higher vertical stiffness and to partly counteract the negative effects of intermittent fasting.

  17. Oxidative stress response in trained men following repeated squats or sprints.

    Science.gov (United States)

    Bloomer, Richard J; Falvo, Michael J; Fry, Andrew C; Schilling, Brian K; Smith, Webb A; Moore, Christopher A

    2006-08-01

    The purpose of this investigation was to measure the oxidative stress response to similarly matched work bouts of squat and sprint exercise. Twelve anaerobically trained men performed six 10-s sprints and, on a separate occasion, repeated barbell squats to approximately equal the amount of work performed during the sprints. Blood lactate, heart rate, and perceived exertion was measured before and following each exercise bout. Muscle soreness, muscle force, and creatine kinase activity was determined preexercise and through 48 h of recovery. Desmin cytoskeletal protein was determined via muscle biopsy of the vastus lateralis before and at 24 h following each exercise. Plasma protein carbonyls (PC) and malondialdehyde (MDA) were measured as biomarkers of oxidative stress. Heart rate and perceived exertion was not different between exercise sessions (P > 0.05), although lactate was higher following sprinting compared with squatting (P = 0.002). Muscle soreness was greater for squatting than sprinting (P = 0.003) and reached a peak immediately postexercise for both sessions (P = 0.0003). Muscle force was unaffected by either exercise session (P > 0.05), and creatine kinase activity was elevated to a similar extent following both sessions. Desmin-negative fibers were virtually nonexistent after either exercise bout, indicating no loss of this cytoskeletal protein. Neither PC nor MDA was affected by the exercise (P > 0.05). These results suggest that in anaerobically trained men, the oxidative stress and muscle injury response to similarly matched anaerobic exercise bouts is minimal, and not different between exercise modes. Furthermore, when compared with previous literature on untrained subjects, the response is significantly attenuated, possibly because of adaptations occurring as a result of chronic, strenuous anaerobic training.

  18. Acute Effects of Plyometric Intervention—Performance Improvement and Related Changes in Sprinting Gait Variability.

    Science.gov (United States)

    Maćkała, Krzysztof; Fostiak, Marek

    2015-07-01

    The purpose of this study was to examine the effect of a short high-intensity plyometric program on the improvement of explosive power of lower extremities and sprint performance as well as changes in sprinting stride variability in male sprinters. Fourteen healthy male sprinters (mean ± SD: age: 18.07 ± 0.73 years, body mass: 73 ± 9.14 kg, height: 180.57 ± 8.16 cm, and best 100 m: 10.89 ± 0.23) participated in the experiment. The experimental protocol included vertical jumping such as squat jump, countermovement jump, and horizontal jumps; standing long jump and standing triple jumps to assess lower-body power, maximal running velocity; a 20-m flying start sprint that evaluated variability of 10 running steps and 60-m starting block sprint. All analyzed parameters were obtained using the new technology of OptoJump-Microgate (OptoJump, Italy). The short-term plyometric training program significantly increased the explosive power of lower extremities, both vertical and horizontal jumping improvement. However, the vertical jumps increased much more than the horizontal. The 20-m improvements were derived from an increase of stride frequency from 4.31 to 4.39 Hz because of a decrease of ground contact time from 138 to 133 milliseconds. This did not translate into step length changes. Therefore, the significantly increased frequency of stride (1.8%), which is a specific expression of ground contact time reduction during support phase, resulted in an increase of speed. The training volume of 2 weeks (with 6 sessions) using high-intensity (between 180 and 250 jumps per session) plyometric exercises can be recommended as the short-term strategy that will optimize one's probability of reaching strong improvements in explosive power and sprint velocity performance.

  19. Factors that Influence the Performance of Elite Sprint Cross-Country Skiers.

    Science.gov (United States)

    Hébert-Losier, Kim; Zinner, Christoph; Platt, Simon; Stöggl, Thomas; Holmberg, Hans-Christer

    2017-02-01

    Sprint events in cross-country skiing are unique not only with respect to their length (0.8-1.8 km), but also in involving four high-intensity heats of ~3 min in duration, separated by a relatively short recovery period (15-60 min). Our aim was to systematically review the scientific literature to identify factors related to the performance of elite sprint cross-country skiers. Four electronic databases were searched using relevant medical subject headings and keywords, as were reference lists, relevant journals, and key authors in the field. Only original research articles addressing physiology, biomechanics, anthropometry, or neuromuscular characteristics and elite sprint cross-country skiers and performance outcomes were included. All articles meeting inclusion criteria were quality assessed. Data were extracted from each article using a standardized form and subsequently summarized. Thirty-one articles met the criteria for inclusion, were reviewed, and scored an average of 66 ± 7 % (range 56-78 %) upon quality assessment. All articles except for two were quasi-experimental, and only one had a fully-experimental research design. In total, articles comprised 567 subjects (74 % male), with only nine articles explicitly reporting their skiers' sprint International Skiing Federation points (weighted mean 116 ± 78). A similar number of articles addressed skating and classical techniques, with more than half of the investigations involving roller-skiing assessments under laboratory conditions. A range of physiological, biomechanical, anthropometric, and neuromuscular characteristics was reported to relate to sprint skiing performance. Both aerobic and anaerobic capacities are important qualities, with the anaerobic system suggested to contribute more to the performance during the first of repeated heats; and the aerobic system during subsequent heats. A capacity for high speed in all the following instances is important for the performance of sprint cross

  20. Career Progression of Junior Professional Officers

    Energy Technology Data Exchange (ETDEWEB)

    Pepper S. E.; Carbonaro J.; Hoffheins, B; Collins, T.

    2015-07-12

    The U.S. Support Program to IAEA Safeguards (USSP) has funded more than 25 Junior Professional Officer (JPO) positions in the IAEA Department of Safeguards since 2005. JPOs are college graduates with zero to two years’ work experience who work alongside experienced IAEA staff members for one to two years and assist with basic, yet essential work while obtaining valuable experience. They contribute to equipment development, testing, integration, open source information collection and analysis, and software and database development. This paper will study the trends in career progression for the JPOs who have completed assignments with the IAEA in the Department of Safeguards. Brookhaven National Laboratory, in its role in managing the USSP, has compiled information that can be analyzed for this purpose.

  1. Pygmalion Effect on Junior English Teaching

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    Yurong Wang

    2014-12-01

    Full Text Available Pygmalion Effect, or Robert Rosenthal Effect, was proved by the famous American psychologist Robert Rosenthal and Jacobson in 1968. Pygmalion Effect, as a matter of fact, is a psychological suggestion, which believes that people can accept the influence and suggestion given by the people whom very much they admire, like, believe, and respect. This effect was first applied in the field of management and medication. What’s more, remarkable achievements have been accomplished on human resource management. Robert Rosenthal put it into education through an experiment called Pygmalion in the Classroom, which aroused widely attention in the education sector. This thesis mainly focuses on the application of Pygmalion effect in English teaching, especially junior English teaching in China. If we can make good use of the Pygmalion Effect to conduct teaching and have positive expectations to students, it will improve teaching greatly.

  2. Wheelchair Propulsion Biomechanics in Junior Basketball Players: A Method for the Evaluation of the Efficacy of a Specific Training Program

    Science.gov (United States)

    Bergamini, Elena; Morelli, Francesca; Marchetti, Flavia; Vannozzi, Giuseppe; Polidori, Lorenzo; Paradisi, Francesco; Traballesi, Marco; Cappozzo, Aurelio

    2015-01-01

    As participation in wheelchair sports increases, the need of quantitative assessment of biomechanical performance indicators and of sports- and population-specific training protocols has become central. The present study focuses on junior wheelchair basketball and aims at (i) proposing a method to identify biomechanical performance indicators of wheelchair propulsion using an instrumented in-field test and (ii) developing a training program specific for the considered population and assessing its efficacy using the proposed method. Twelve athletes (10 M, 2 F, age = 17.1 ± 2.7 years, years of practice = 4.5 ± 1.8) equipped with wheelchair- and wrist-mounted inertial sensors performed a 20-metre sprint test. Biomechanical parameters related to propulsion timing, progression force, and coordination were estimated from the measured accelerations and used in a regression model where the time to complete the test was set as dependent variable. Force- and coordination-related parameters accounted for 80% of the dependent variable variance. Based on these results, a training program was designed and administered for three months to six of the athletes (the others acting as control group). The biomechanical indicators proved to be effective in providing additional information about the wheelchair propulsion technique with respect to the final test outcome and demonstrated the efficacy of the developed program. PMID:26543852

  3. Wheelchair Propulsion Biomechanics in Junior Basketball Players: A Method for the Evaluation of the Efficacy of a Specific Training Program.

    Science.gov (United States)

    Bergamini, Elena; Morelli, Francesca; Marchetti, Flavia; Vannozzi, Giuseppe; Polidori, Lorenzo; Paradisi, Francesco; Traballesi, Marco; Cappozzo, Aurelio; Delussu, Anna Sofia

    2015-01-01

    As participation in wheelchair sports increases, the need of quantitative assessment of biomechanical performance indicators and of sports- and population-specific training protocols has become central. The present study focuses on junior wheelchair basketball and aims at (i) proposing a method to identify biomechanical performance indicators of wheelchair propulsion using an instrumented in-field test and (ii) developing a training program specific for the considered population and assessing its efficacy using the proposed method. Twelve athletes (10 M, 2 F, age = 17.1 ± 2.7 years, years of practice = 4.5 ± 1.8) equipped with wheelchair- and wrist-mounted inertial sensors performed a 20-metre sprint test. Biomechanical parameters related to propulsion timing, progression force, and coordination were estimated from the measured accelerations and used in a regression model where the time to complete the test was set as dependent variable. Force- and coordination-related parameters accounted for 80% of the dependent variable variance. Based on these results, a training program was designed and administered for three months to six of the athletes (the others acting as control group). The biomechanical indicators proved to be effective in providing additional information about the wheelchair propulsion technique with respect to the final test outcome and demonstrated the efficacy of the developed program.

  4. Wheelchair Propulsion Biomechanics in Junior Basketball Players: A Method for the Evaluation of the Efficacy of a Specific Training Program

    Directory of Open Access Journals (Sweden)

    Elena Bergamini

    2015-01-01

    Full Text Available As participation in wheelchair sports increases, the need of quantitative assessment of biomechanical performance indicators and of sports- and population-specific training protocols has become central. The present study focuses on junior wheelchair basketball and aims at (i proposing a method to identify biomechanical performance indicators of wheelchair propulsion using an instrumented in-field test and (ii developing a training program specific for the considered population and assessing its efficacy using the proposed method. Twelve athletes (10 M, 2 F, age = 17.1 ± 2.7 years, years of practice = 4.5 ± 1.8 equipped with wheelchair- and wrist-mounted inertial sensors performed a 20-metre sprint test. Biomechanical parameters related to propulsion timing, progression force, and coordination were estimated from the measured accelerations and used in a regression model where the time to complete the test was set as dependent variable. Force- and coordination-related parameters accounted for 80% of the dependent variable variance. Based on these results, a training program was designed and administered for three months to six of the athletes (the others acting as control group. The biomechanical indicators proved to be effective in providing additional information about the wheelchair propulsion technique with respect to the final test outcome and demonstrated the efficacy of the developed program.

  5. Identifying the Physical Fitness, Anthropometric and Athletic Movement Qualities Discriminant of Developmental Level in Elite Junior Australian Football: Implications for the Development of Talent.

    Science.gov (United States)

    Gaudion, Sarah L; Doma, Kenji; Sinclair, Wade; Banyard, Harry G; Woods, Carl T

    2017-07-01

    Gaudion, SL, Doma, K, Sinclair, W, Banyard, HG, and Woods, CT. Identifying the physical fitness, anthropometric and athletic movement qualities discriminant of developmental level in elite junior Australian football: implications for the development of talent. J Strength Cond Res 31(7): 1830-1839, 2017-This study aimed to identify the physical fitness, anthropometric and athletic movement qualities discriminant of developmental level in elite junior Australian football (AF). From a total of 77 players, 2 groups were defined according to their developmental level; under 16 (U16) (n = 40, 15.6 to 15.9 years), and U18 (n = 37, 17.1 to 17.9 years). Players performed a test battery consisting of 7 physical fitness assessments, 2 anthropometric measurements, and a fundamental athletic movement assessment. A multivariate analysis of variance tested the main effect of developmental level (2 levels: U16 and U18) on the assessment criterions, whilst binary logistic regression models and receiver operating characteristic (ROC) curves were built to identify the qualities most discriminant of developmental level. A significant effect of developmental level was evident on 9 of the assessments (d = 0.27-0.88; p ≤ 0.05). However, it was a combination of body mass, dynamic vertical jump height (nondominant leg), repeat sprint time, and the score on the 20-m multistage fitness test that provided the greatest association with developmental level (Akaike's information criterion = 80.84). The ROC curve was maximized with a combined score of 180.7, successfully discriminating 89 and 60% of the U18 and U16 players, respectively (area under the curve = 79.3%). These results indicate that there are distinctive physical fitness and anthropometric qualities discriminant of developmental level within the junior AF talent pathway. Coaches should consider these differences when designing training interventions at the U16 level to assist with the development of prospective U18 AF players.

  6. Neuro-mechanical determinants of repeated treadmill sprints - Usefulness of an ‘hypoxic to normoxic recovery’ approach

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    Olivier eGIRARD

    2015-09-01

    Full Text Available To improve our understanding of the limiting factors during repeated sprinting, we manipulated hypoxia severity during an initial set and examined the effects on performance and associated neuro-mechanical alterations during a subsequent set performed in normoxia. On separate days, thirteen active males performed eight 5-s sprints (recovery = 25 s on an instrumented treadmill in either normoxia near sea-level (SL; FiO2 = 20.9%, moderate (MH; FiO2 = 16.8% or severe normobaric hypoxia (SH; FiO2 = 13.3% followed, 6 min later, by four 5-s sprints (recovery = 25 s in normoxia. Throughout the first set, along with distance covered [larger sprint decrement score in SH (-8.2% compared to SL (-5.3% and MH (-7.2%; P<0.05], changes in contact time, step frequency and root mean square activity (surface electromyography of the quadriceps (rectus femoris muscle in SH exceeded those in SL and MH (P<0.05. During first sprint of the subsequent normoxic set, the distance covered (99.6%, 96.4% and 98.3% of sprint 1 in SL, MH and SH, respectively, the main kinetic (mean, horizontal and resultant forces and kinematic (contact time and step frequency variables as well as surface electromyogram of quadriceps and plantar flexor muscles were fully recovered, with no significant difference between conditions. Despite differing hypoxic severity levels during sprints 1 to 8, performance and neuro-mechanical patterns did not differ during the four sprints of the second set performed in normoxia. In summary, under the circumstances of this study (participant background, exercise-to-rest ratio, hypoxia exposure, sprint mechanical performance and neural alterations were largerly influenced by the hypoxia severity in an initial set of repeated sprints. However, hypoxia had no residual effect during a subsequent set performed in normoxia. Hence, the recovery of performance and associated neuro-mechanical alterations was complete after resting for 6 min near sea level, with a

  7. Neuro-mechanical determinants of repeated treadmill sprints - Usefulness of an “hypoxic to normoxic recovery” approach

    Science.gov (United States)

    Girard, Olivier; Brocherie, Franck; Morin, Jean-Benoit; Millet, Grégoire P.

    2015-01-01

    To improve our understanding of the limiting factors during repeated sprinting, we manipulated hypoxia severity during an initial set and examined the effects on performance and associated neuro-mechanical alterations during a subsequent set performed in normoxia. On separate days, 13 active males performed eight 5-s sprints (recovery = 25 s) on an instrumented treadmill in either normoxia near sea-level (SL; FiO2 = 20.9%), moderate (MH; FiO2 = 16.8%) or severe normobaric hypoxia (SH; FiO2 = 13.3%) followed, 6 min later, by four 5-s sprints (recovery = 25 s) in normoxia. Throughout the first set, along with distance covered [larger sprint decrement score in SH (−8.2%) compared to SL (−5.3%) and MH (−7.2%); P < 0.05], changes in contact time, step frequency and root mean square activity (surface electromyography) of the quadriceps (Rectus femoris muscle) in SH exceeded those in SL and MH (P < 0.05). During first sprint of the subsequent normoxic set, the distance covered (99.6, 96.4, and 98.3% of sprint 1 in SL, MH, and SH, respectively), the main kinetic (mean vertical, horizontal, and resultant forces) and kinematic (contact time and step frequency) variables as well as surface electromyogram of quadriceps and plantar flexor muscles were fully recovered, with no significant difference between conditions. Despite differing hypoxic severity levels during sprints 1–8, performance and neuro-mechanical patterns did not differ during the four sprints of the second set performed in normoxia. In summary, under the circumstances of this study (participant background, exercise-to-rest ratio, hypoxia exposure), sprint mechanical performance and neural alterations were largely influenced by the hypoxia severity in an initial set of repeated sprints. However, hypoxia had no residual effect during a subsequent set performed in normoxia. Hence, the recovery of performance and associated neuro-mechanical alterations was complete after resting for 6 min near sea level

  8. A Clustered Repeated-Sprint Running Protocol for Team-Sport Athletes Performed in Normobaric Hypoxia

    Directory of Open Access Journals (Sweden)

    Jaime Morrison, Chris McLellan, Clare Minahan

    2015-12-01

    Full Text Available The present study compared the performance (peak speed, distance, and acceleration of ten amateur team-sport athletes during a clustered (i.e., multiple sets repeated-sprint protocol, (4 sets of 4, 4-s running sprints; i.e., RSR444 in normobaric normoxia (FiO2 = 0.209; i.e., RSN with normobaric hypoxia (FiO2 = 0.140; i.e., RSH. Subjects completed two separate trials (i. RSN, ii. RSH; randomised order between 48 h and 72 h apart on a non-motorized treadmill. In addition to performance, we examined blood lactate concentration [La-] and arterial oxygen saturation (SpO2 before, during, and after the RSR444. While there were no differences in peak speed or distance during set 1 or set 2, peak speed (p = 0.04 and 0.02, respectively and distance (p = 0.04 and 0.02, respectively were greater during set 3 and set 4 of RSN compared with RSH. There was no difference in the average acceleration achieved in set 1 (p = 0.45, set 2 (p = 0.26, or set 3 (p = 0.23 between RSN and RSH; however, the average acceleration was greater in RSN than RSH in set 4 (p < 0.01. Measurements of [La-] were higher during RSH than RSN immediately after Sprint 16 (10.2 ± 2.5 vs 8.6 ± 2.6 mM; p = 0.02. Estimations of SpO2 were lower during RSH than RSN, respectively, immediately prior to the commencement of the test (89.0 ± 2.0 vs 97.2 ± 1.5 %, post Sprint 8 (78.0 ± 6.3 vs 93.8 ± 3.6 % and post Sprint 16 (75.3 ± 6.3 vs 94.5 ± 2.5 %; all p < 0.01. In summary, the RSR444 is a practical protocol for the implementation of a hypoxic repeated-sprint training intervention into the training schedules of team-sport athletes. However, given the inability of amateur team-sport athletes to maintain performance in hypoxic (FiO2 = 0.140 conditions, the potential for specific training outcomes (i.e. speed to be achieved will be compromised, thus suggesting that the RSR444 should be used with caution.

  9. Five Weeks of Sprint and High-Intensity Interval Training Improves Paddling Performance in Adolescent Surfers.

    Science.gov (United States)

    Farley, Oliver R L; Secomb, Josh L; Parsonage, Joanna R; Lundgren, Lina E; Abbiss, Chris R; Sheppard, Jeremy M

    2016-09-01

    Farley, ORL, Secomb, JL, Parsonage, JR, Lundgren, LE, Abbiss, CR, and Sheppard, JM. Five weeks of sprint and high-intensity interval training improves paddling performance in adolescent surfers. J Strength Cond Res 30(9): 2446-2452, 2016-The purpose of our study was to examine the effects of sprint interval training (SIT; 10 seconds) and high-intensity interval training (HIT; 30 seconds) on surfing athletes paddling performance (400-m time trial and repeat-sprint paddle performance). Twenty-four competitive adolescent surfers (19 male, 5 female; age = 14.4 ± 1.3 years, mass: 50.1 ± 10.7 kg, and stature: 159.9 ± 10.3 cm) were assigned to perform either 5 weeks of SIT and HIT. Participants completed a repeated-sprint paddle ability test (RSPT, 15-m surfboard sprint paddle initiated every 40 seconds × 10 bouts) and 400-m endurance surfboard paddle time trial before and after training. High-intensity interval training decreased the total time to complete the 400 m by 15.8 ± 16.1 seconds (p = 0.03), and SIT decreased the total time to complete the RSPT by 6.5 ± 4.3 seconds (p = 0.02). Fatigue index during the RSPT (first-slowest effort) was lower after HIT and SIT (p ≤ 0.001 and p = 0.02, respectively). There were no significant differences in performance changes in the 400 m (total time) and RSPT (total time, fastest 15 m time, and peak velocity) between HIT and SIT. Our study indicates that HIT and SIT may be implemented to the training program of surfers to improve aerobic and repeat-sprint paddle ability, both of which are identified as key aspects of the sport. In addition, these findings indicate that 400-m paddle and RSPT can discriminate between aerobic and anaerobic training adaptations, with aerobic gains likely from HIT and anaerobic gains from SIT.

  10. A comparison of maximal squat strength and 5-, 10-, and 20-meter sprint times, in athletes and recreationally trained men.

    Science.gov (United States)

    Comfort, Paul; Bullock, Nathan; Pearson, Stephen J

    2012-04-01

    The purpose of this study was to identify whether there was a relationship between relative strength during a 1 repetition maximum (1RM) back squat and 5-, 10-, and 20-m sprint performances in both trained athletes and recreationally trained individuals. Professional rugby league players (n = 24) and recreationally trained individuals (n = 20) participated in this investigation. Twenty-meter sprint time and 1RM back squat strength, using free weights, were assessed on different days. There were no significant (p ≥ 0.05) differences between the well-trained and recreationally trained groups for 5-m sprint times. In contrast, the well-trained group's 10- and 20-m sprint times were significantly quicker (p = 0.004; p = 0.002) (1.78 + 0.06 seconds; 3.03 + 0.09 seconds) compared with the recreationally trained group (1.84 + 0.07 seconds; 3.13 + 0.11 seconds). The athletes were significantly stronger (170.63 + 21.43 kg) than the recreationally trained individuals (135.45 + 30.07 kg) (p = 0.01); however, there were no significant differences (p > 0.05) in relative strength between groups (1.78 + 0.27 kg/kg; 1.78 + 0.33 kg/kg, respectively). Significant negative correlations were found between 5-m sprint time and relative squat strength (r = -0.613, power = 0.96, p = 0.004) and between relative squat strength and 10- and 20-m sprint times in the recreationally trained group (r = -0.621, power = 0.51, p = 0.003; r = -0.604, power = 0.53, p = 0.005, respectively). These results, indicating that relative strength, are important for initial sprint acceleration in all athletes but more strongly related to sprint performance over greater distances in recreationally trained individuals.

  11. Four weeks of running sprint interval training improves cardiorespiratory fitness in young and middle-aged adults.

    Science.gov (United States)

    Willoughby, Taura N; Thomas, Matthew P L; Schmale, Matthew S; Copeland, Jennifer L; Hazell, Tom J

    2016-01-01

    The purpose of this study was to determine the effectiveness of a 4-week running sprint interval training protocol to improve both aerobic and anaerobic fitness in middle-aged adults (40-50 years) as well as compare the adaptations to younger adults (20-30 years). Twenty-eight inactive participants - 14 young 20-30-year-olds (n = 7 males) and 14 middle-aged 40-50-year-olds (n = 5 males) - completed 4 weeks of running sprint interval training (4 to 6, 30-s "all-out" sprints on a curved, self-propelled treadmill separated by 4 min active recovery performed 3 times per week). Before and after training, all participants were assessed for maximal oxygen consumption (VO2max), 2000 m time trial performance, and anaerobic performance on a single 30-s sprint. There were no interactions between group and time for any tested variable, although training improved relative VO2max (young = 3.9, middle-aged = 5.2%; P < 0.04), time trial performance (young = 5.9, middle-aged = 8.2%; P < 0.001), peak sprint speed (young = 9.3, middle-aged = 2.2%; P < 0.001), and average sprint speed (young = 6.8, middle-aged = 11.6%; P < 0.001) in both young and middle-aged groups from pre- to post-training on the 30-s sprint test. The current study demonstrates that a 4-week running sprint interval training programme is equally effective at improving aerobic and anaerobic fitness in younger and middle-aged adults.

  12. Acute and Post-Exercise Physiological Responses to High-Intensity Interval Training in Endurance and Sprint Athletes

    OpenAIRE

    Cipryan, Lukas; Tschakert, Gerhard; Hofmann, Peter

    2017-01-01

    The purpose of the presented study was to compare acute and post-exercise differences in cardiorespiratory, metabolic, cardiac autonomic, inflammatory and muscle damage responses to high-intensity interval exercise (HIIT) between endurance and sprint athletes. The study group consisted of sixteen highly-trained males (age 22.1 �� 2.5 years) participating in endurance (n = 8) or sprint (n = 8) sporting events. All the participants underwent three exercise sessions: short HIIT (work interval du...

  13. Acute and Post-Exercise Physiological Responses to High-Intensity Interval Training in Endurance and Sprint Athletes

    OpenAIRE

    Lukas Cipryan, Gerhard Tschakert, Peter Hofmann

    2017-01-01

    The purpose of the presented study was to compare acute and post-exercise differences in cardiorespiratory, metabolic, cardiac autonomic, inflammatory and muscle damage responses to high-intensity interval exercise (HIIT) between endurance and sprint athletes. The study group consisted of sixteen highly-trained males (age 22.1 ± 2.5 years) participating in endurance (n = 8) or sprint (n = 8) sporting events. All the participants underwent three exercise sessions: short HIIT (work interval dur...

  14. Effect of the coefficient of friction of a running surface on sprint time in a sled-towing exercise.

    Science.gov (United States)

    Linthorne, Nicholas P; Cooper, James E

    2013-06-01

    This study investigated the effect of the coefficient of friction of a running surface on an athlete's sprint time in a sled-towing exercise. The coefficients of friction of four common sports surfaces (a synthetic athletics track, a natural grass rugby pitch, a 3G football pitch, and an artificial grass hockey pitch) were determined from the force required to tow a weighted sled across the surface. Timing gates were then used to measure the 30-m sprint time for six rugby players when towing a sled of varied weight across the surfaces. There were substantial differences between the coefficients of friction for the four surfaces (micro = 0.21-0.58), and in the sled-towing exercise the athlete's 30-m sprint time increased linearly with increasing sled weight. The hockey pitch (which had the lowest coefficient of friction) produced a substantially lower rate of increase in 30-m sprint time, but there were no significant differences between the other surfaces. The results indicate that although an athlete's sprint time in a sled-towing exercise is affected by the coefficient offriction of the surface, the relationship relationship between the athlete's rate of increase in 30-m sprint time and the coefficient of friction is more complex than expected.

  15. EFFECT OF MUSCLE ENERGY TECHNIQUE ON FLEXIBILITY OF HAMSTRING AND CALF MUSCLES AND SPRINTING PERFORMANCE IN SPRINTERS

    Directory of Open Access Journals (Sweden)

    M. Prasad Naik

    2015-10-01

    Full Text Available Background: Muscle energy technique is used for restoring normal tone in hypertonic muscles, strengthening weak muscles, preparing muscle for subsequent stretching, one of the main uses of this method is to normalize joint range which may help in increase flexibility and performance in sprinters. The aim of the study is to evaluate the effect of muscle energy technique on flexibility of hamstrings and calf muscles and sprinting performance in sprinters. The objective of the study is to determine the muscle energy technique on hamstrings and calf muscle flexibility and sprinting performance in sprinters by using goniometer and timing of sprinting performance. Method: The study design is an experimental study in which 30 male sprinters were recruited in this study. The study sample included all male healthy sprinters, aged between 15 -30 years. All subjects received warm up, muscle energy technique and cool down exercises daily for a period of 6weeks.The outcome measures are 90°-90°popliteal angle for assessing hamstring flexibility and ROM of ankle joint for calf muscles by universal goniometer and sprinting performance time by using stopwatch. Results: Independent t-test and paired t- test are used to analyse the data. A significant difference was found between pre and post values of hamstring and calf muscle flexibility and sprinting performance after the analysis in this study. Conclusion: This study shows that there was a significant effect of MET on hamstring and calf muscle flexibility and sprinting performance.

  16. The Effect of Acceleration Sprint and Zig-zag Drill Combination to Increase Students’ Speed and Agility

    Science.gov (United States)

    Bana, O.; Mintarto, E.; Kusnanik, N. W.

    2018-01-01

    The purpose of this research is to analyze the following factors: (1) how far the effect of exercise acceleration sprint on the speed and agility (2) how much influence the zig-zag drill combination to the speed and agility (3) and is there any difference between the effects of exercise acceleration sprint and practice zig-zag drill combination of the speed and agility. This research is quantitative with quasi-experimental approach. The design of this study is matching only design.This study was conducted on 33 male students who take part in extracurricular and divided into 3 groups with 11 students in each group. Group 1 was given training of acceleration sprint, group 2 was given zig-zag training combination drills of conventional and exercises for group 3, for 8 weeks. The data collection was using sprint 30 meter to test the speed and agility t-test to test agility. Data were analyzed using t-test and analysis of variance. The conclusion of the research is (1) there is a significant effect of exercise acceleration sprint for the speed and agility, (2) there is a significant influence combination zig-zag drills, on speed and agility (3) and exercise acceleration sprint have more effect on the speed and agility.

  17. REPEATED SPRINT ABILITY AND RECOVERY PERIOD: COMPARISON OF TRAINED AND UNTRAINED INDIVIDUALS

    OpenAIRE

    Sultan

    2016-01-01

    The purpose of the study was to investigate the effects of training both in repeated sprint ability (RSA) and during the recovery after sprint. Soccer players playing in regional amateur league (n=14, age: 21.86±2.35 years, height: 180.14±4.54 cm, body mass: 72.57±5.03 kg, training age: 8.71±1.86 years) and students from faculty of sport sciences that played soccer in the past (n=13, age: 23.77±2.65 years, height: 178.54±4.67 cm, body mass: 74.54±10.52 kg) participated in this study as traine...

  18. On the performance of Usain Bolt in the 100 m sprint

    Science.gov (United States)

    Hernández Gómez, J. J.; Marquina, V.; Gómez, R. W.

    2013-09-01

    Many university texts on mechanics consider the effect of air drag force, using the slowing down of a parachute as an example. Very few discuss what happens when the drag force is proportional to both u and u2. In this paper we deal with a real problem to illustrate the effect of both terms on the speed of a runner: a theoretical model of the world-record 100 m sprint of Usain Bolt during the 2009 World Championships in Berlin is developed, assuming a drag force proportional to u and to u2. The resulting equation of motion is solved and fitted to the experimental data obtained from the International Association of Athletics Federations, which recorded Bolt's position with a laser velocity guard device. It is worth noting that our model works only for short sprints.

  19. Effect of sprint cycle training on activities of antioxidant enzymes in human skeletal muscle

    DEFF Research Database (Denmark)

    Hellsten, Ylva; Apple, F. S.; Sjödin, B.

    1996-01-01

    (P anaerobic capacity in the trained muscle. The present study demonstrates that intermittent sprint cycle training that induces an enhanced capacity for anaerobic energy generation also improves......The effect of intermittent sprint cycle training on the level of muscle antioxidant enzyme protection was investigated. Resting muscle biopsies, obtained before and after 6 wk of training and 3, 24, and 72 h after the final session of an additional 1 wk of more frequent training, were analyzed...... for activities of the antioxidant enzymes glutathione peroxidase (GPX), glutathione reductase (GR), and superoxide dismutase (SOD). Activities of several muscle metabolic enzymes were determined to assess the effectiveness of the training. After the first 6-wk training period, no change in GPX, GR, or SOD...

  20. Energy system contributions and determinants of performance in sprint cross-country skiing

    DEFF Research Database (Denmark)

    Andersson, E; Björklund, G; Holmberg, H-C

    2017-01-01

    To improve current understanding of energy contributions and determinants of sprint-skiing performance, 11 well-trained male cross-country skiers were tested in the laboratory for VO2max , submaximal gross efficiency (GE), maximal roller skiing velocity, and sprint time-trial (STT) performance...... during the STT was predicted from the submaximal relationships for GE against velocity and incline, allowing computation of metabolic rate and O2 deficit. The skiers completed the STT in 232 ± 10 s (distributed as 55 ± 3% DP and 45 ± 3% DS) with a mean power output of 324 ± 26 W. The anaerobic energy......-skiing has demonstrated an anaerobic energy contribution of 18%, with GE being the strongest predictor of performance....

  1. Sprint: The first flight demonstration of the external work system robots

    Science.gov (United States)

    Price, Charles R.; Grimm, Keith

    1995-01-01

    The External Works Systems (EWS) 'X Program' is a new NASA initiative that will, in the next ten years, develop a new generation of space robots for active and participative support of zero g external operations. The robotic development will center on three areas: the assistant robot, the associate robot, and the surrogate robot that will support external vehicular activities (EVA) prior to and after, during, and instead of space-suited human external activities respectively. The EWS robotics program will be a combination of technology developments and flight demonstrations for operational proof of concept. The first EWS flight will be a flying camera called 'Sprint' that will seek to demonstrate operationally flexible, remote viewing capability for EVA operations, inspections, and contingencies for the space shuttle and space station. This paper describes the need for Sprint and its characteristics.

  2. Reducing fat and sodium content in pork sausage | Junior | African ...

    African Journals Online (AJOL)

    Reducing fat and sodium content in pork sausage. Jonhny De Azevedo Maia Junior, Fábio Da Costa Henry, Felipe Roberto Ferreira Amaral Do Valle, Meire Lelis Leal Martins, Célia Raquel Quirino, Rafael Dos Santos Costa ...

  3. Transforming Junior Leader Development: Developing the Next Generation of Pentathletes

    National Research Council Canada - National Science Library

    Haynes, Kenneth G

    2007-01-01

    .... The convergence of Full Spectrum Operations, Network Centric Warfare, and Krulak's "Three Block War" have facilitated an urgent need for junior leaders that are more capable, adaptive, and mature...

  4. Gender and Acquisition of Science Process Skills among Junior ...

    African Journals Online (AJOL)

    Gender and Acquisition of Science Process Skills among Junior Secondary ... for the effective learning of science even at the primary or basic level of education. ... and that activity-based methods of instruction be employed in teaching Basic ...

  5. On Stimulating English Learning Motivation of Junior Middle School Students

    Institute of Scientific and Technical Information of China (English)

    朱梦萱

    2016-01-01

    Learning motivation plays an important role in students’ English learning process. This thesis first introduces the definition and classification of motivation and then puts forward some measures and strategies that can foster and motivate junior middle school students’ learning motivation.

  6. Personality Dimensions of Gifted and Talented Junior High Students.

    Science.gov (United States)

    Rosenblatt, Howard S.; And Others

    1980-01-01

    Compared to a peer group of average abilities, gifted and talented junior high school students appeared more outgoing, participating, insightful, fast-learning, intellectually adaptable, conscientious, persistent, and moralistic, thus indicating significant between-group differences. (SB)

  7. The Relationship between Repeated Sprint Performance and Velocity Values during Loaded-Squat Jump Exercise

    Science.gov (United States)

    Can, Ibrahim; Sadik, Seda; Bayrakdaroglu, Serdar

    2018-01-01

    The purpose of this study is to investigate the relationship between repeated sprint performance and velocity values during loaded-squat jump exercise. In accordance with this purpose, 23 kickboxing athletes (age: 21,1 ± 2,10 years; height: 178,7 ± 5,01 cm; weight: 70,8 ± 7,85 kg) participated voluntarily in this study. Participants were performed…

  8. Influence of physical development on start and countermovement jump performance in adolescent sprint athletes.

    Science.gov (United States)

    Aerenhouts, D; Debaere, S; Hagman, F; Van Gheluwe, B; Delecluse, C; Clarys, P

    2013-02-01

    The aim of the present study was to describe the effect of physical changes during adolescence on sprint start and countermovement jump (CMJ) performance. Twenty-eight girls and 25 boys (15.0±1.6 and 14.7±1.9 years at start respectively) were measured twice with a one year interval. Anthropometric data allowed skeletal muscle mass (SMM) estimation. Athletes performed a 10m sprint tracked from behind by a laser sensor, with starting blocks measuring propulsion forces. CMJ's were performed on a Kistler force plate. Between the two measurement occasions both genders increased in body height, weight and SMM. In girls and boys, impulse during the push-off, block leaving velocity and times at 5 and 10 m improved significantly. In both genders CMJ absolute power increased but not power.kg-1. Only in boys a higher CMJ was registered on occasion 2. For both genders on both occasions, impulse during the push-off correlated with body weight, SMM and CMJ power (r from .46 to .84), and in boys also with CMJ height and CMJ power.kg-1 (r from 0.43 to 0.76). Boys showed CMJ height and power to correlate with 5 and 10 m times (r from -0.42 to -0.79) and with block leaving velocity, however only on the first data collection (r=0.61 and 0.59, respectively). Sprint start performance is only partly related to muscular development and CMJ could predict start performance in boys only. Sprint start and CMJ rely on technical skills and, therefore, increasing muscularity should be accompanied with sufficient specific training to allow an optimal transfer to start performance.

  9. How Joint Torques Affect Hamstring Injury Risk in Sprinting Swing–Stance Transition

    Science.gov (United States)

    SUN, YULIANG; WEI, SHUTAO; ZHONG, YUNJIAN; FU, WEIJIE; LI, LI; LIU, YU

    2015-01-01

    ABSTRACT Purpose The potential mechanisms of hamstring strain injuries in athletes are not well understood. The study, therefore, was aimed at understanding hamstring mechanics by studying loading conditions during maximum-effort overground sprinting. Methods Three-dimensional kinematics and ground reaction force data were collected from eight elite male sprinters sprinting at their maximum effort. Maximal isometric torques of the hip and knee were also collected. Data from the sprinting gait cycle were analyzed via an intersegmental dynamics approach, and the different joint torque components were calculated. Results During the initial stance phase, the ground reaction force passed anteriorly to the knee and hip, producing an extension torque at the knee and a flexion torque at the hip joint. Thus, the active muscle torque functioned to produce flexion torque at the knee and extension torque at the hip. The maximal muscle torque at the knee joint was 1.4 times the maximal isometric knee flexion torque. During the late swing phase, the muscle torque counterbalanced the motion-dependent torque and acted to flex the knee joint and extend the hip joint. The loading conditions on the hamstring muscles were similar to those of the initial stance phase. Conclusions During both the initial stance and late swing phases, the large passive torques at both the knee and hip joints acted to lengthen the hamstring muscles. The active muscle torques generated mainly by the hamstrings functioned to counteract those passive effects. As a result, during sprinting or high-speed locomotion, the hamstring muscles may be more susceptible to high risk of strain injury during these two phases. PMID:24911288

  10. Effects of four weeks of repeated sprint training on physiological indices in futsal players

    Directory of Open Access Journals (Sweden)

    Paulo Cesar do Nascimento

    2014-12-01

    Full Text Available DOI: http://dx.doi.org/10.5007/1980-0037.2015v17n1p91   The aim of this study was to investigate the effects of short repeated-sprint ability (RSA training on the neuromuscular and physiological indices in U17 futsal players during the competitive period. Fourteen players were divided into two groups: intervention group (n = 8 and control group (n = 6. Both groups performed a repeated maximal sprint test (40-m MST, intermittent shuttle-running test (Carminatti’s test and vertical jumps before and after the training period. The intervention group was submitted to an additional four-week repeated sprints program, twice a week, while the control group maintained their normal training routine. There was no significant interaction between time and groups for all variables analysed (p > 0.05. However, a significant main effect was observed for time (p < 0.01 indicating an increase on speed at heart rate deflection point (VHRDP and the continuous jump performance while the peak lactate (40m-LACpeak and sprint decrement decreased after training, in both groups. Still, based on effect sizes (ES the greater changes with practical relevance were verified for intervention group in important variables such as peak velocity (ES = 0,71, VHRDP (ES = 0,83 and 40m-LACpeak (ES = 1,00. This study showed that RSA-based and normal training routine are equally effective in producing changes in the analysed variables during a short period of intervention. However, the effect size suggests that four weeks of RSA training would be a minimum time that could induce the first changes of futsal player’s physical fitness.

  11. Sprinting performance and resistance based training interventions: A systematic review with meta-analysis

    OpenAIRE

    Bolger, Richard; Kenny, Ian; Lyons, Mark; Harrison, Andrew J.

    2014-01-01

    peer-reviewed Introduction Much of the research which focuses on improving sprinting performance has been carried out with team sport athletes or endurance athletes (Berryman, Maurel, & Bosquet, 2010; Esteve-Lanao, Rhea, Fleck, & Lucia, 2008; Hanon, Bernard, Rabate, & Claire, 2012; Rhea, Kenn, & Dermody, 2009; Shalfawi, Haugen, Jakobsen, Enoksen, & T??nnessen, 2013; West et al., 2013). There is little consensus with the prescription of resistance based training within this body of resea...

  12. Effect of cluster set warm-up configurations on sprint performance in collegiate male soccer players.

    Science.gov (United States)

    Nickerson, Brett S; Mangine, Gerald T; Williams, Tyler D; Martinez, Ismael A

    2018-06-01

    The purpose of this study was to determine if back squat cluster sets (CS) with varying inter-repetition rest periods would potentiate greater sprint performance compared with a traditional set parallel back squat in collegiate soccer players. Twelve collegiate male soccer players (age, 21.0 ± 2.0 years; height, 180.0 ± 9.0 cm; body mass, 79.0 ± 9.5 kg) performed a 20-m sprint prior to a potentiation complex and at 1, 4, 7, and 10 min postexercise on 3 separate, randomized occasions. On each occasion, the potentiation complex consisted of 1 set of 3 repetitions at 85% 1-repetition maximum (1RM) for the traditional parallel back squat. However, on 1 occasion the 3-repetition set was performed in a traditional manner (i.e., continuously), whereas on the other 2 occasions, 30s (CS 30 ) and 60 s (CS 60 ) of rest were allotted between each repetition. Repeated-measures ANOVA revealed greater (p = 0.022) mean barbell velocity on CS 60 compared with the traditional set. However, faster (p < 0.040) 20-m sprint times were observed for CS 30 (3.15 ± 0.16 s) compared with traditional (3.20 ± 0.17 s) only at 10 min postexercise. No other differences were observed. These data suggest that a single cluster set of 3 repetitions with 30-s inter-repetition rest periods at 85% 1RM acutely improves 20-m sprinting performance. Strength and conditioning professionals and their athletes might consider its inclusion during the specific warm-up to acutely improve athletic performance during the onset (≤10 min) of training or competition.

  13. How joint torques affect hamstring injury risk in sprinting swing-stance transition.

    Science.gov (United States)

    Sun, Yuliang; Wei, Shutao; Zhong, Yunjian; Fu, Weijie; Li, Li; Liu, Yu

    2015-02-01

    The potential mechanisms of hamstring strain injuries in athletes are not well understood. The study, therefore, was aimed at understanding hamstring mechanics by studying loading conditions during maximum-effort overground sprinting. Three-dimensional kinematics and ground reaction force data were collected from eight elite male sprinters sprinting at their maximum effort. Maximal isometric torques of the hip and knee were also collected. Data from the sprinting gait cycle were analyzed via an intersegmental dynamics approach, and the different joint torque components were calculated. During the initial stance phase, the ground reaction force passed anteriorly to the knee and hip, producing an extension torque at the knee and a flexion torque at the hip joint. Thus, the active muscle torque functioned to produce flexion torque at the knee and extension torque at the hip. The maximal muscle torque at the knee joint was 1.4 times the maximal isometric knee flexion torque. During the late swing phase, the muscle torque counterbalanced the motion-dependent torque and acted to flex the knee joint and extend the hip joint. The loading conditions on the hamstring muscles were similar to those of the initial stance phase. During both the initial stance and late swing phases, the large passive torques at both the knee and hip joints acted to lengthen the hamstring muscles. The active muscle torques generated mainly by the hamstrings functioned to counteract those passive effects. As a result, during sprinting or high-speed locomotion, the hamstring muscles may be more susceptible to high risk of strain injury during these two phases.

  14. Adaptive Changes After 2 Weeks of 10-s Sprint Interval Training With Various Recovery Times

    Directory of Open Access Journals (Sweden)

    Robert A. Olek

    2018-04-01

    Full Text Available Purpose: The aim of this study was to compare the effect of applying two different rest recovery times in a 10-s sprint interval training session on aerobic and anaerobic capacities as well as skeletal muscle enzyme activities.Methods: Fourteen physically active but not highly trained male subjects (mean maximal oxygen uptake 50.5 ± 1.0 mlO2·kg−1·min−1 participated in the study. The training protocol involved a series of 10-s sprints separated by either 1-min (SIT10:1 or 4-min (SIT10:4 of recovery. The number of sprints progressed from four to six over six sessions separated by 1–2 days rest. Pre and post intervention anthropometric measurements, assessment of aerobic, anaerobic capacity and muscle biopsy were performed. In the muscle samples maximal activities of citrate synthase (CS, 3-hydroxyacylCoA dehydrogenase (HADH, carnitine palmitoyl-transferase (CPT, malate dehydrogenase (MDH, and its mitochondrial form (mMDH, as well as lactate dehydrogenase (LDH were determined. Analysis of variance was performed to determine changes between conditions.Results: Maximal oxygen uptake improved significantly in both training groups, by 13.6% in SIT10:1 and 11.9% in SIT10:4, with no difference between groups. Wingate anaerobic test results indicated main effect of time for total work, peak power output and mean power output, which increased significantly and similarly in both groups. Significant differences between training groups were observed for end power output, which increased by 10.8% in SIT10:1, but remained unchanged in SIT10:4. Both training protocols induced similar increase in CS activity (main effect of time p < 0.05, but no other enzymes.Conclusion: Sprint interval training protocols induce metabolic adaptation over a short period of time, and the reduced recovery between bouts may attenuate fatigue during maximal exercise.

  15. Coffee and Caffeine Ingestion Have Little Effect on Repeated Sprint Cycling in Relatively Untrained Males

    Directory of Open Access Journals (Sweden)

    Neil Clarke

    2016-08-01

    Full Text Available The present study investigated the effect of ingesting caffeine-dose-matched anhydrous caffeine or coffee on the performance of repeated sprints. Twelve recreationally active males (mean ± SD age: 22 ± 2 years, height: 1.78 ± 0.07 m, body mass: 81 ± 16 kg completed eighteen 4 s sprints with 116 s recovery on a cycle ergometer on four separate occasions in a double-blind, randomised, counterbalanced crossover design. Participants ingested either 3 mg·kg−1 of caffeine (CAF, 0.09 g·kg−1 coffee, which provided 3 mg·kg−1 of caffeine (COF, a taste-matched placebo beverage (PLA, or a control condition (CON 45 min prior to commencing the exercise protocol. Peak and mean power output and rating of perceived exertion (RPE were recorded for each sprint. There were no significant differences in peak power output (CAF: 949 ± 199 W, COF: 949 ± 174 W, PLA: 971 ± 149 W and CON: 975 ± 170 W; p = 0.872; η P 2 = 0.02 or mean power output (CAF: 873 ± 172 W, COF: 862 ± 44 W, PLA: 887 ± 119 W and CON: 892 ± 143 W; p = 0.819; η P 2 = 0.03 between experimental conditions. Mean RPE was similar for all trials (CAF: 11 ± 2, COF: 11 ± 2, PLA: 11 ± 2 and CON: 11 ± 2; p = 0.927; η P 2 = 0.01. Neither the ingestion of COF or CAF improved repeated sprint cycling performance in relatively untrained males.

  16. A Study on Coping Patterns of Junior College Students

    OpenAIRE

    Ramya, N.; Parthasarathy, R.

    2009-01-01

    The objective of this study was to examine the coping patterns followed by the junior college students. Further, an extensive effort was done to study the gender differences in coping patterns used by the students. This study was conducted in Christ College, Bangalore and on the first and second-year students of pre-university studying in either of the branches (Bachelor of Arts, Science, or Commerce). A total of 120 samples were collected from study population of junior college students usin...

  17. Gordon Ramsay's Politeness Strategies in Masterchef and Masterchef Junior Us

    OpenAIRE

    Safa, Annisa Friska; Kurniawan, Eri

    2015-01-01

    This research aims to investigate the types of politeness strategies that are performed by Gordon Ramsay in judging the Masterchef US and Masterchef Junior US contestants' dishes and to reveal whether Gordon Ramsay performs any different politeness strategies between the Master chef and Masterchef Junior contestants. The data spring from Gordon Ramsay utterances, taken from the elimination test of two episodes of Masterchef season 4 (episode 9 and 12) and the elimination test of two episodes ...

  18. Differences in activation properties of the hamstring muscles during overground sprinting.

    Science.gov (United States)

    Higashihara, Ayako; Nagano, Yasuharu; Ono, Takashi; Fukubayashi, Toru

    2015-09-01

    The purpose of this study was to quantify activation of the biceps femoris (BF) and medial hamstring (MH) during overground sprinting. Lower-extremity kinematics and electromyography (EMG) of the BF and MH were recorded in 13 male sprinters performing overground sprinting at maximum effort. Mean EMG activity was calculated in the early stance, late stance, mid-swing, and late-swing phases. Activation of the BF was significantly greater during the early stance phase than the late stance phase (p<0.01). Activation of the BF muscle was significantly lower during the first half of the mid-swing phase than the other phases (p<0.05). The MH had significantly greater EMG activation relative to its recorded maximum values compared to that for the BF during the late stance (p<0.05) and mid-swing (p<0.01) phases. These results indicate that the BF shows high activation before and after foot contact, while the MH shows high activation during the late stance and mid-swing phases. We concluded that the activation properties of the BF and MH muscles differ within the sprinting gait cycle. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Advancing hypoxic training in team sports: from intermittent hypoxic training to repeated sprint training in hypoxia.

    Science.gov (United States)

    Faiss, Raphaël; Girard, Olivier; Millet, Grégoire P

    2013-12-01

    Over the past two decades, intermittent hypoxic training (IHT), that is, a method where athletes live at or near sea level but train under hypoxic conditions, has gained unprecedented popularity. By adding the stress of hypoxia during 'aerobic' or 'anaerobic' interval training, it is believed that IHT would potentiate greater performance improvements compared to similar training at sea level. A thorough analysis of studies including IHT, however, leads to strikingly poor benefits for sea-level performance improvement, compared to the same training method performed in normoxia. Despite the positive molecular adaptations observed after various IHT modalities, the characteristics of optimal training stimulus in hypoxia are still unclear and their functional translation in terms of whole-body performance enhancement is minimal. To overcome some of the inherent limitations of IHT (lower training stimulus due to hypoxia), recent studies have successfully investigated a new training method based on the repetition of short (<30 s) 'all-out' sprints with incomplete recoveries in hypoxia, the so-called repeated sprint training in hypoxia (RSH). The aims of the present review are therefore threefold: first, to summarise the main mechanisms for interval training and repeated sprint training in normoxia. Second, to critically analyse the results of the studies involving high-intensity exercises performed in hypoxia for sea-level performance enhancement by differentiating IHT and RSH. Third, to discuss the potential mechanisms underpinning the effectiveness of those methods, and their inherent limitations, along with the new research avenues surrounding this topic.

  20. Mechanical Properties of Sprinting in Elite Rugby Union and Rugby League.

    Science.gov (United States)

    Cross, Matt R; Brughelli, Matt; Brown, Scott R; Samozino, Pierre; Gill, Nicholas D; Cronin, John B; Morin, Jean-Benoît

    2015-09-01

    To compare mechanical properties of overground sprint running in elite rugby union and rugby league athletes. Thirty elite rugby code (15 rugby union and 15 rugby league) athletes participated in this cross-sectional analysis. Radar was used to measure maximal overground sprint performance over 20 or 30 m (forwards and backs, respectively). In addition to time at 2, 5, 10, 20, and 30 m, velocity-time signals were analyzed to derive external horizontal force-velocity relationships with a recently validated method. From this relationship, the maximal theoretical velocity, external relative and absolute horizontal force, horizontal power, and optimal horizontal force for peak power production were determined. While differences in maximal velocity were unclear between codes, rugby union backs produced moderately faster split times, with the most substantial differences occurring at 2 and 5 m (ES 0.95 and 0.86, respectively). In addition, rugby union backs produced moderately larger relative horizontal force, optimal force, and peak power capabilities than rugby league backs (ES 0.73-0.77). Rugby union forwards had a higher absolute force (ES 0.77) despite having ~12% more body weight than rugby league forwards. In this elite sample, rugby union athletes typically displayed greater short-distance sprint performance, which may be linked to an ability to generate high levels of horizontal force and power. The acceleration characteristics presented in this study could be a result of the individual movement and positional demands of each code.

  1. Reliability and Usefulness of Linear Sprint Testing in Adolescent Rugby Union and League Players.

    Science.gov (United States)

    Darrall-Jones, Joshua D; Jones, Ben; Roe, Gregory; Till, Kevin

    2016-05-01

    The purpose of this study was to evaluate (a) whether there were differences in sprint times at 5, 10, 20, 30, and 40 m between rugby union and rugby league players, (b) determine the reliability and usefulness of linear sprint testing in adolescent rugby players. Data were collected on 28 rugby union and league academy players over 2 testing sessions, with 3-day rest between sessions. Rugby league players were faster at 5 m than rugby union players, with further difference unclear. Sprint time at 10, 20, 30, and 40 m was all reliable (coefficient of variation [CV] = 3.1, 1.8, 2.0, and 1.3%) but greater than the smallest worthwhile change (SWC [0.2 × between-subject SD]), rating the test as marginal for usefulness. Although the test was incapable of detecting the SWC, we recommend that practitioners and researchers use Hopkins' proposed method; whereby plotting the change score of the individual at each split (±typical error [TE] expressed as a CV) against the SWC and visually inspecting whether the TE crosses into the SWC are capable of identifying whether a change is both real (greater than the noise of the test, i.e., >TE) and of practical significance (>SWC). Researchers and practitioners can use the TE and SWC from this study to assess changes in performance of adolescent rugby players when using single beam timing gates.

  2. Relationship between lower limbs kinematic variables and effectiveness of sprint during maximum velocity phase.

    Science.gov (United States)

    Struzik, Artur; Konieczny, Grzegorz; Grzesik, Kamila; Stawarz, Mateusz; Winiarski, Sławomir; Rokita, Andrzej

    2015-01-01

    The aim of the study was to determine the relationships between time of running over a 15-25 m section of a 30-meter run along a straight line and changes in the angle and angular velocity observed in ankle, knee and hip joints. Therefore, the authors attempted to answer the question of whether a technique of lower limbs movement during the phase of sprint maximum velocity significantly correlates with the time of running over this section. A group of 14 young people from the Lower Silesia Voivodeship Team participated in the experiment. A Fusion Smart Speed System was employed for running time measurements. The kinematic data were recorded using Noraxon MyoMotion system. There were observed statistically significant relationships between sprint time over a section from 15 to 25 m and left hip rotation (positive) and between this time and left and right ankle joint dorsi-plantar flexion (negative). During the maximum velocity phase of a 30 m sprint, the effect of dorsi-plantar flexion performed in the whole range of motion was found to be beneficial. This can be attributed to the use of elastic energy released in the stride cycle. Further, hip rotation should be minimized, which makes the stride aligned more along a line of running (a straight line) instead of from side to side.

  3. Adipose tissue extracts plasma ammonia after sprint exercise in women and men

    DEFF Research Database (Denmark)

    Esbjörnsson, Mona; Bülow, Jens; Norman, Barbara

    2006-01-01

    This study evaluates a possible contribution of adipose tissue to the elimination of plasma ammonia (NH(3)) after high-intensity sprint exercise. In 14 healthy men and women, repeated blood samples for plasma NH(3) analyses were obtained from brachial artery and from a subcutaneous abdominal vein......) with glutamate resulting in its conversion to glutamine. Adipose tissue may thus play an important physiological role in eliminating plasma NH(3) and thereby reducing the risk of NH(3) intoxication after high-intensity exercise.......This study evaluates a possible contribution of adipose tissue to the elimination of plasma ammonia (NH(3)) after high-intensity sprint exercise. In 14 healthy men and women, repeated blood samples for plasma NH(3) analyses were obtained from brachial artery and from a subcutaneous abdominal vein...... before and after three repeated 30-s cycle sprints separated by 20 min of recovery. Biopsies from subcutaneous abdominal adipose tissue were obtained and analyzed for glutamine and glutamate content. After exercise, both arterial and abdominal venous plasma NH(3) concentrations were lower in women than...

  4. Características y efectos de los métodos resistidos en el sprint

    Directory of Open Access Journals (Sweden)

    Pedro E. Alcaraz

    2009-01-01

    Full Text Available Para la mejora del rendimiento en el sprint se utilizan distintos métodos de entrenamiento, entre los más populares se encuentran los métodos resistidos. Un método resistido para el sprint se caracteriza por utilizar sprints con una sobrecarga o resistencia añadida. Dependiendo de las características del dispositivo, tanto la magnitud como la dirección de la resistencia va a ser diferente. Así, existen distintos tipos de métodos resistidos, estos son: arrastres de trineos o ruedas, lastres de chalecos o cinturones, arrastres de paracaídas, carreras cuesta arriba, e incluso carreras sobre la arena de la playa. El principal objetivo al usar métodos resistidos es mejorar la fuerza específica de los deportistas sin producir una modificación significativa de la técnica del deportista. En el presente trabajo se revisan las características y efectos de los métodos resistidos tanto de forma aguda, como sus efectos a corto, medio y largo plazo.

  5. Effects of the Nordic Hamstring exercise on sprint capacity in male football players: a randomized controlled trial.

    Science.gov (United States)

    Ishøi, Lasse; Hölmich, Per; Aagaard, Per; Thorborg, Kristian; Bandholm, Thomas; Serner, Andreas

    2018-07-01

    This assessor-blinded, randomized controlled superiority trial investigated the efficacy of the 10-week Nordic Hamstring exercise (NHE) protocol on sprint performance in football players. Thirty-five amateur male players (age: 17-26 years) were randomized to a do-as-usual control group (CG; n = 17) or to 10-weeks of supervised strength training using the NHE in-season (IG; n = 18). A repeated-sprint test, consisting of 4 × 6 10 m sprints, with 15 s recovery period between sprints and 180 s between sets, was conducted to evaluate total sprint time as the primary outcome. Secondary outcomes were best 10 m sprint time (10mST) and sprint time during the last sprint (L10mST). Additionally, peak eccentric hamstring strength (ECC-P HS ) and eccentric hamstring strength capacity (ECC-CAP HS ) were measured during the NHE. Ten players were lost to follow-up, thus 25 players were analyzed (CG n = 14; IG n = 11). Between-group differences in mean changes were observed in favor of the IG for sprint performance outcomes; TST (-0.649 s, p = 0.056, d = 0.38), 10mST (-0.047 s, p = 0.005, d = 0.64) and L10mST (-0.052 s, p = 0.094, d = 0.59), and for strength outcomes; ECC-P HS (62.3 N, p = 0.006, d = 0.92), and ECC-CAP HS (951 N, p = 0.005, d = 0.95). In conclusion, the NHE showed small-to-medium improvements in sprint performance and large increases in peak eccentric hamstring strength and capacity. NCT02674919.

  6. Technical characteristics of elite junior men and women race walkers.

    Science.gov (United States)

    Hanley, B; Bissas, A; Drake, A

    2014-12-01

    Successful coaching in race walking requires a thorough understanding of the biomechanical principles underlying this unique form of gait. The purpose of this study was to analyze elite male and female junior race walkers and identify key kinematic variables. Twenty junior men and 20 junior women were videoed as they competed over 10 km in the 8th European Cup Race Walking. Three-dimensional kinematic data were obtained using motion analysis software (SIMI, Munich). Step length and cadence were correlated with speed in both sexes, and greater step lengths were the kinematic reason for junior men's faster walking speeds. While cadence did not differ between junior men and junior women, there was a difference in proportion of step time spent in contact. There were some differences between genders for upper body joint angles (e.g., elbow) but there were few differences within lower limb joint angles. Although some technical aspects (e.g., pelvic and shoulder girdle rotation) appeared undeveloped, it was noteworthy that most athletes achieved full knee extension at initial contact in accordance with the rules. However, in many athletes flight times were evident that might present problems during the transition to the higher standards of senior competition. There was a large range of ability among both sexes and coaches are advised to ensure that technical development continues during the transition to senior competition.

  7. Has ADVANCE Affected Senior Compared to Junior Women Scientists Differently?

    Science.gov (United States)

    Rosser, Sue

    2015-01-01

    Substantial evidence exists to demonstrate that the NSF ADVANCE Inititiative has made a positive impact upon institutions. Since it began in 2001, ADVANCE has changed the conversation, policies, and practices in ways to remove obstacles and systemic barriers preventing success for academic women scientists and engineers. Results from ADVANCE projects on campuses have facilitated consensus nationally about policies and practices that institutions may implement to help to alleviate issues, particularly for junior women scientists.Although getting women into senior and leadership positions in STEM constituted an initial impetus for ADVANCE, less emphasis was placed upon the needs of senior women scientists. Surveys of academic women scientists indicate that the issues faced by junior and senior women scientists differ significantly. The focus of ADVANCE on junior women in many ways seemed appropriate--the senior cohort of women scinetists is fed by the junior cohort of scientists; senior women serve as mentors, role models, and leaders for the junior colleagues, while continuing to struggle to achieve full status in the profession. This presentation will center on the differences in issues faced by senior compared to junior women scientists to explore whether a next step for ADVANCE should be to address needs of senior academic women scientists.

  8. Epistaxis management: current understanding amongst junior doctors.

    Science.gov (United States)

    Fox, R; Nash, R; Liu, Z-W; Singh, A

    2016-03-01

    Epistaxis is a common and potentially life-threatening emergency. This survey assesses understanding and confidence in epistaxis management amongst current junior doctors. A cross-sectional study was conducted of foundation year one and two doctors based at three National Health Service trusts within a single region of the UK, assessing basic understanding and procedural confidence. A total of 111 foundation doctors completed this survey. The average duration of undergraduate exposure to otolaryngology was 8.1 days. Forty-one per cent of respondents stated that they would apply pressure to the nasal bones to control epistaxis. Seventy-five per cent lacked confidence in their ability to manage epistaxis. Those with two weeks or more of undergraduate exposure to otolaryngology were more confident than those with one week or less of exposure (p epistaxis management, with patient safety implications. Confidence is associated with the duration of undergraduate exposure to otolaryngology. A minimum emergency safe competency should be a priority during foundation training if not achieved in UK medical schools.

  9. Breakfast Composition in Junior High School Students

    Directory of Open Access Journals (Sweden)

    Sheila Devi

    2015-12-01

    Full Text Available Background: Adolescence is a time of rapid development that requires higher nutrient intake levels than in adulthood. However the habit of skipping breakfast has become very popular among adolescents. Skipping breakfast has negative effects such as difficulty in concentrating, growth impairment and decrease academic performance. Therefore, this study was conducted to identify the breakfast composisition of early adolescents in Jatinangor, Sumedang, Indonesia. Methods: A cross sectional study with non-probability sampling method, was conducted in a junior high school Jatinangor during the month of July 2013. Ninety six participants were included in this study. All the participants underwent an interview about the food intake for breakfast in seven days using eating pattern recall guidelines. Results: Overall, 37% of the respondents skipped breakfast. The mean of total calories among the adolescents who consumed breakfast was 286.06 (187.89 kcal. The amount of carbohydrate, fat and protein consumed was 29.23 (19.93 gram, 13.93 (13.29 gram and 8.78 (6.11 gram accordingly. The main reason for adolescent to skip breakfast was lack of time. Conclusions: Majority of the respondents have their breakfast before they go to school. Overall, the total calories comsumed is sufficient however the amount of protein consumed is low.

  10. Recruitment strategies and challenges in a large intervention trial: Systolic Blood Pressure Intervention Trial (SPRINT)

    Science.gov (United States)

    Ramsey, Thomas M; Snyder, Joni K; Lovato, Laura C; Roumie, Christianne L; Glasser, Steven P; Cosgrove, Nora M; Olney, Christine M; Tang, Rocky H; Johnson, Karen C; Still, Carolyn H; Gren, Lisa H; Childs, Jeffery C; Crago, Osa L; Summerson, John H; Walsh, Sandy M; Perdue, Letitia H; Bankowski, Denise M; Goff, David C

    2016-01-01

    Background The Systolic Blood Pressure Intervention Trial (SPRINT) is a multicenter, randomized clinical trial of 9,361 participants with hypertension who are ≥ 50 years old. The trial is designed to evaluate the effect of intensive systolic blood pressure control (systolic blood pressure goal recruitment strategies and lessons learned during recruitment of the SPRINT cohort and five targeted participant subgroups: pre-existing cardiovascular disease, pre-existing chronic kidney disease, age ≥ 75 years, women, and minorities. Methods In collaboration with the National Institutes of Health Project Office and SPRINT Coordinating Center, five Clinical Center Networks oversaw clinical site selection, recruitment, and trial activities. Recruitment began November 8, 2010 and ended March 15, 2013 (about 28 months). Various recruitment strategies were used, including mass mailing, brochures, referrals from healthcare providers or friends, posters, newspaper ads, radio ads, and electronic medical record searches. Results Recruitment was scheduled to last 24 months to enroll a target of 9,250 participants; in just over 28 months, the trial enrolled 9,361 participants. The trial screened 14,692 volunteers, with 33% of initial screens originating from the use of mass mailing lists. Screening results show that participants also responded to recruitment efforts through referral by SPRINT staff, healthcare providers, or friends (45%); brochures or posters placed in clinic waiting areas (15%); and television, radio, newspaper, internet ads, or toll-free numbers (8%). The overall recruitment yield (number randomized /number screened) was 64% (9,361 randomized /14,692 screened), 77% for those with cardiovascular disease, 79% for those with chronic kidney disease, 70% for those age ≥ 75 years, 55% for women, and 61% for minorities. As recruitment was observed to lag behind expectations, additional clinics were included and inclusion criteria were broadened, keeping event rates

  11. The effects of maturation on jumping ability and sprint adaptations to plyometric training in youth soccer players.

    Science.gov (United States)

    Asadi, Abbas; Ramirez-Campillo, Rodrigo; Arazi, Hamid; Sáez de Villarreal, Eduardo

    2018-04-03

    The aim of this study was to investigate the effects of maturation on power and sprint performance adaptations following 6 weeks of plyometric training in youth soccer players during pre-season. Sixty male soccer players were categorized into 3 maturity groups (Pre, Mid and Post peak height velocity [PHV]) and then randomly assigned to plyometric group and control group. Vertical jump, standing long jump, and 20-m sprint (with and without ball) tests were collected before- and after-intervention. After the intervention, the Pre, Mid and Post-PHV groups showed significant (P ≤ 0.05) and small to moderate effect size (ES) improvement in vertical jump (ES = 0.48; 0.57; 0.73), peak power output (E = 0.60; 0.64; 0.76), standing long jump (ES = 0.62; 0.65; 0.7), 20-m sprint (ES = -0.58; -0.66), and 20-m sprint with ball (ES = -0.44; -0.8; -0.55) performances. The Post-PHV soccer players indicated greater gains than Pre-PHV in vertical jump and sprint performance after training (P ≤ 0.05). Short-term plyometric training had positive effects on sprinting and jumping-power which are important determinants of match-winning actions in soccer. These results indicate that a sixty foot contact, twice per week program, seems effective in improving power and sprint performance in youth soccer players.

  12. Relationship Between Jumping Ability, Agility and Sprint Performance of Elite Young Basketball Players: A Field-Test Approach

    Directory of Open Access Journals (Sweden)

    Abbas Asadi

    2016-05-01

    Full Text Available DOI: http://dx.doi.org/10.5007/1980-0037.2016v18n2p177   The purpose of this study was to determine the relationships between sprint, agility and jump performance of elite young basketball players. Sixteen elite national level young male basketball players participated in this study. The jumping ability of each player was determined using countermovement jump (CMJ, and broad long jump (BLJ. The agility T test (TT and Illinois agility test (IAT were assessed to determine the agility, and 20-m sprint time was also measured to determine sprint performance. The results of Pearson Product Moment Correlation analysis indicated moderate correlation between training age and IAT (r = -0.57; p = 0.021. Strong correlations were found between CMJ and BLJ (r = 0.71; p = 0.002, and between TT and IAT (r = 0.70; p = 0.002. Similarly, 20-m sprint time was strong correlated with CMJ (r = -0.61; p = 0.011, BLJ (r = -0.76; p = 0.001, TT (r = 0.77; p = 0.001, and IAT (r = 0.68; p = 0.003. In addition, CMJ was strongly correlated with TT (r = -0.60; p = 0.013, and IAT (r = -0.64; p = 0.007, and also strong correlation between BLJ with TT (r = -0.85; p = 0.001 and IAT (r = -0.76; p = 0.001. The findings of the present study indicated significant correlation between sprint and agility, jumping ability and sprint performance and between jumping ability and agility performance in basketball players. Therefore, the results suggest that sprint, agility and jumping ability share common physiological and biomechanical determinants.

  13. Skeletal Muscle Pyruvate Dehydrogenase Phosphorylation and Lactate Accumulation During Sprint Exercise in Normoxia and Severe Acute Hypoxia: Effects of Antioxidants

    Directory of Open Access Journals (Sweden)

    David Morales-Alamo

    2018-03-01

    Full Text Available Compared to normoxia, during sprint exercise in severe acute hypoxia the glycolytic rate is increased leading to greater lactate accumulation, acidification, and oxidative stress. To determine the role played by pyruvate dehydrogenase (PDH activation and reactive nitrogen and oxygen species (RNOS in muscle lactate accumulation, nine volunteers performed a single 30-s sprint (Wingate test on four occasions: two after the ingestion of placebo and another two following the intake of antioxidants, while breathing either hypoxic gas (PIO2 = 75 mmHg or room air (PIO2 = 143 mmHg. Vastus lateralis muscle biopsies were obtained before, immediately after, 30 and 120 min post-sprint. Antioxidants reduced the glycolytic rate without altering performance or VO2. Immediately after the sprints, Ser293- and Ser300-PDH-E1α phosphorylations were reduced to similar levels in all conditions (~66 and 91%, respectively. However, 30 min into recovery Ser293-PDH-E1α phosphorylation reached pre-exercise values while Ser300-PDH-E1α was still reduced by 44%. Thirty minutes after the sprint Ser293-PDH-E1α phosphorylation was greater with antioxidants, resulting in 74% higher muscle lactate concentration. Changes in Ser293 and Ser300-PDH-E1α phosphorylation from pre to immediately after the sprints were linearly related after placebo (r = 0.74, P < 0.001; n = 18, but not after antioxidants ingestion (r = 0.35, P = 0.15. In summary, lactate accumulation during sprint exercise in severe acute hypoxia is not caused by a reduced activation of the PDH. The ingestion of antioxidants is associated with increased PDH re-phosphorylation and slower elimination of muscle lactate during the recovery period. Ser293 re-phosphorylates at a faster rate than Ser300-PDH-E1α during the recovery period, suggesting slightly different regulatory mechanisms.

  14. Junior empresa: un modelo empresarial diferente = Junior enterprise: a different business model

    Directory of Open Access Journals (Sweden)

    Javier Jiménez

    2013-12-01

    Full Text Available Resumen ¿Quién no está harto ya de oír cómo está el mercado laboral? Nos bombardean con un ruido de fondo incesante, como si graduarnos no fuese suficiente reto. Bueno, ¿y qué? Un grupo de estudiantes de la Escuela Técnica Superior de Ingeniería y Diseño Industrial de la Universidad Politécnica de Madrid (ETSIDI-UPM nos hemos unido y hemos creado nuestra propia Junior Empresa, un modelo empresarial diferente, innovador, que nos permite revertir todos los beneficios en aprendizaje. ¿Quién ha dicho que tengamos que dejarnos vencer por un sistema laboral obsoleto? Abstract Are you tired of hearing how difficult it is to get a job? They are filling our minds with a non-stop background noise, as if getting a degree was an insufficient challenge. So what? Well, some students from the Superior Technical School of Engineering and Industrial Design from the Technical University of Madrid (ETSIDIUPM have come together and created our own Junior Enterprise, a different business model, an innovative canvas, which allows us to transform all the benefits into learning. Who said our destiny is being crushed by an obsolete labour market?

  15. Solar Heating Proof-of-Concept Experiment for a Public School Building.

    Science.gov (United States)

    Merrill, Glen L.

    Results and conclusions to date of a program to design, erect, and test a 5,000-square-foot solar energy system are presented in this report. The program described demonstrates the ability of solar collectors to supplement the heating and hot water requirements of North View Junior High School in suburban Minneapolis. The report discusses in…

  16. Bullying and harassment – Are junior doctors always the victims?

    International Nuclear Information System (INIS)

    Nyhsen, C.M.; Patel, P.; O'Connell, J.E.

    2016-01-01

    Introduction: NHS staff have the right to work in an environment free from bullying, harassment and violence. There should be good team-working with colleagues from all disciplines. Reports of bullying experienced by junior doctors resulted in mandatory annual GMC surveys regarding the quality of training. This led to medical trainees being surveyed more than any other staff. Radiographers informally reported bullying and harassment (B&H) incidents involving trainees. This survey aims to quantify the issue. Methods: Online survey of general and CT radiographers at a large acute hospital in the North East of England addressing incidents involving junior doctors and occurring in the preceding 12 months. Results: The survey was completed by 86% (44/51) general and 5/7 CT radiographers. Overall 45% experienced bullying, 92% had their own/witnessed a colleague's opinion being ignored and 57% were the target of loud verbal abuse/anger or witnessed colleagues being treated in that way. Several radiographers reported 5 or more B&H incidents. 26 radiographers (51%) were shouted at/ridiculed in theatre, 4 feeling unsafe/physically threatened. Junior doctors regularly queried the need to supervise CT contrast injections on call. Free text comments highlighted that doctors rarely introduced themselves to radiology staff. Conclusion: Radiographers report significant incidents of B&H involving junior doctors, who do not always seem to appreciate radiation exposure legislation, patient safety protocols or respect the seniority of highly trained radiographers. Measures introduced subsequently include guidance for radiographers, a dedicated radiology e-learning package for trainees and classroom sessions for foundation doctors and final year undergraduate students. - Highlights: • Bullying and harassment of radiographers is a persistent problem. • Some radiographers reported feeling physically threatened in theatre. • Some junior doctors do not respect radiation exposure

  17. Acute effect of a complex training protocol of back squats on 30-m sprint times of elite male military athletes.

    Science.gov (United States)

    Ojeda, Álvaro Huerta; Ríos, Luis Chirosa; Barrilao, Rafael Guisado; Serrano, Pablo Cáceres

    2016-03-01

    [Purpose] The aim of this study was to determine the acute effect temporal of a complex training protocol on 30 meter sprint times. A secondary objective was to evaluate the fatigue indexes of military athletes. [Subjects and Methods] Seven military athletes were the subjects of this study. The variables measured were times in 30-meter sprint, and average power and peak power of squats. The intervention session with complex training consisted of 4 sets of 5 repetitions at 30% 1RM + 4 repetitions at 60% 1RM + 3 repetitions of 30 meters with 120-second rests. For the statistical analysis repeated measures of ANOVA was used, and for the post hoc analysis, student's t-test was used. [Results] Times in 30 meter sprints showed a significant reduction between the control set and the four experimental sets, but the average power and peak power of squats did not show significant changes. [Conclusion] The results of the study show the acute positive effect of complex training, over time, in 30-meter sprint by military athletes. This effect is due to the post activation potentiation of the lower limbs' muscles in the 30 meters sprint.

  18. Comparison of three types of full-body compression garments on throwing and repeat-sprint performance in cricket players.

    Science.gov (United States)

    Duffield, Rob; Portus, Marc

    2007-07-01

    To compare the effects of three types of full-body compression garments (Skins, Adidas and Under Armour) on repeat-sprint and throwing performance in cricket players. Following familiarisation, 10 male cricket players performed four randomised exercise sessions (3 garments and a control). Each session involved a 30 min repeat-sprint exercise protocol comprising 20 m sprints every minute, separated by submaximal exercise. Throwing tests included a pre-exercise and a postexercise maximal distance test and accuracy throwing tests. During each session, measures of heart rate, skin temperature, change in body mass, rate of perceived exertion and perceived muscle soreness were recorded. Capillary blood samples were analysed before and after exercise for lactate, pH, O(2) saturation and O(2) partial pressure, and 24 h after exercise for creatine kinase (CK). Ratings of perceived muscle soreness were also obtained 24 h after exercise. No significant differences (p>0.05) were evident in repeat-sprint performance (10 m, 20 m time or total submaximal distance covered) or throwing performance (maximum distance or accuracy). No significant differences (p>0.05) were observed in heart rate, body mass change or blood measures during exercise. Significant differences (p0.05). No benefit was noted when wearing compression garments for repeat-sprint or throwing performance; however, the use of the garments as a recovery tool, when worn after exercise, may be beneficial to reduce postexercise trauma and perceived muscle soreness.

  19. Repeated sprint ability and stride kinematics are altered following an official match in national-level basketball players.

    Science.gov (United States)

    Delextrat, A; Baliqi, F; Clarke, N

    2013-04-01

    The aim of the study was to investigate the effects of playing an official national-level basketball match on repeated sprint ability (RSA) and stride kinematics. Nine male starting basketball players (22.8±2.2 years old, 191.3±5.8 cm, 88±10.3 kg, 12.3±4.6% body fat) volunteered to take part. Six repetitions of maximal 4-s sprints were performed on a non-motorised treadmill, separated by 21-s of passive recovery, before and immediately after playing an official match. Fluid loss, playing time, and the frequencies of the main match activities were recorded. The peak, mean, and performance decrement for average and maximal speed, acceleration, power, vertical and horizontal forces, and stride parameters were calculated over the six sprints. Differences between pre- and post-match were assessed by student t-tests. Significant differences between pre- and post-tests were observed in mean speed (-3.3%), peak and mean horizontal forces (-4.3% and -17.4%), peak and mean vertical forces (-3.4% and -3.7%), contact time (+7.3%), stride duration (+4.6%) and stride frequency (-4.0%), (Pvertical force were significantly correlated to fluid loss and sprint, jump and shuffle frequencies (P<0.05). These results highlight that the impairment in repeated sprint ability depends on the specific activities performed, and that replacing fluid loss through sweating during a match is crucial.

  20. Solar Indices - Solar Flares

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of indices related to solar activity contributed by a number of national and private solar observatories located worldwide. This...

  1. Solar Indices - Solar Ultraviolet

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of indices related to solar activity contributed by a number of national and private solar observatories located worldwide. This...

  2. Solar Indices - Solar Corona

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of indices related to solar activity contributed by a number of national and private solar observatories located worldwide. This...

  3. Solar Indices - Solar Irradiance

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of indices related to solar activity contributed by a number of national and private solar observatories located worldwide. This...

  4. The Junior Faculty Laboratory: an innovative model of peer mentoring.

    Science.gov (United States)

    Johnson, Kimberly S; Hastings, S Nicole; Purser, Jama L; Whitson, Heather E

    2011-12-01

    Mentoring in academic medicine has been shown to contribute to the success of junior faculty, resulting in increased productivity, career satisfaction, and opportunities for networking. Although traditional dyadic mentoring, involving one senior faculty member and one junior protégé, is the dominant model for mentoring in the academic environment, there is increasing recognition that the sharing of knowledge, skills, and experiences among peers may also contribute to the career development of junior faculty. The authors describe the structure, activities, and outcomes of the Junior Faculty Laboratory (JFL), a self-organized, flexible, and dynamic peer-mentoring model within the Duke University Center for the Study of Aging and Human Development. As an innovative mentoring model, JFL is entirely peer driven, and its activities are determined by the real-time needs of members. In contrast to some other peer-mentoring models, JFL lacks senior faculty input or a structured curriculum, members are multidisciplinary, meeting times are project driven rather than preset, and participation in collaborative projects is optional based on the interests and needs of group members. Additionally, JFL was not formed as a substitute for, but as a complement to, the dyadic mentoring relationships enjoyed by its members. The model, now in its fifth year, has demonstrated success and sustainability. The authors present the JFL as an innovative, mentoring model that can be reproduced by other junior faculty seeking to foster collegial relationships with peers while simultaneously enhancing their career development.

  5. Perceived Injury Risk among Junior Cricketers: A Cross Sectional Survey

    Directory of Open Access Journals (Sweden)

    Prasanna J. Gamage

    2017-08-01

    Full Text Available Understanding how junior athletes perceive injury risks when participating in sport and the environment they play in is an important component of injury prevention. This study investigates how Sri Lankan junior cricketers (n = 365, aged 11–14 years, boys perceive injury risks associated with playing cricket. The study used a Sri Lankan modification of an Australian junior cricket injury risk perception survey that considered playing cricket versus other sports, different cricket playing positions and roles, and different ground conditions. The risk of playing cricket was considered to be greater than that for cycling, but lower than that for rugby and soccer. Fast-bowlers, batters facing fast-bowlers, fielding close in the field, and wicket-keeping without a helmet were perceived to pose greater risks of injury than other scenarios. Playing on hard, bumpy and/or wet ground conditions were perceived to have a high risk opposed to playing on a grass field. Fielding in the outfield and wicket-keeping to fast-bowlers whilst wearing a helmet were perceived as low risk actions. The risk perceptions of junior cricketers identified in this study, do not necessarily reflect the true injury risk in some instances. This information will inform the development of injury prevention education interventions to address these risk perceptions in junior cricketers.

  6. Investigating the Relationship between Sprint and Jump Performances with Velocity and Power Parameters during Propulsive Phase of the Loaded-Squat Jump Exercise

    Science.gov (United States)

    Can, Ibrahim

    2018-01-01

    The purpose of this study was to investigate the relationship between sprint and jump performance with velocity parameters in the loaded-squat jump exercise (SQ[subscript Loaded]). In accordance with this purpose, a total of 13 athletes competing in martial sports have participated in this study voluntarily. In this study, sprint tests, vertical…

  7. Stronger vection in junior high school children than in adults.

    Science.gov (United States)

    Shirai, Nobu; Imura, Tomoko; Tamura, Rio; Seno, Takeharu

    2014-01-01

    Previous studies have shown that even elementary school-aged children (7 and 11 years old) experience visually induced perception of illusory self-motion (vection) (Lepecq et al., 1995, Perception, 24, 435-449) and that children of a similar age (mean age = 9.2 years) experience more rapid and stronger vection than do adults (Shirai et al., 2012, Perception, 41, 1399-1402). These findings imply that although elementary school-aged children experience vection, this ability is subject to further development. To examine the subsequent development of vection, we compared junior high school students' (N = 11, mean age = 14.4 years) and adults' (N = 10, mean age = 22.2 years) experiences of vection. Junior high school students reported significantly stronger vection than did adults, suggesting that the perceptual experience of junior high school students differs from that of adults with regard to vection and that this ability undergoes gradual changes over a relatively long period of development.

  8. Sprint and jump performance in elite male soccer players following a 10-week Nordic Hamstring exercise Protocol

    DEFF Research Database (Denmark)

    Krommes, K.; Petersen, J.; Nielsen, M. B.

    2017-01-01

    OBJECTIVE: The preseason Nordic Hamstring Protocol (NHP) reduces hamstring strain injuries in football players. Despite persisting injury rates, elite clubs are reluctant to apply the NHP often over concerns of negative impacts on performance. This pilot study investigated if sprint or jump...... split times) and countermovement jump (CMJ height) was measured before the mid-seasonal break and again after 10 weeks of performing the NHP at the end of pre-season. Dropouts were due to transfers and injuries unrelated to performing NHP (NHP = 0, CG = 5). Sprint performance on the short split...... to negatively affect sprint and vertical jump performance outcomes in the present study, while in fact showing some promise for the more explosive characteristics such as the short 5 and 10 m split-times and maximal CMJ height, which all are highly relevant performance parameters in elite football....

  9. The recovery of repeated-sprint exercise is associated with PCr resynthesis, while muscle pH and EMG amplitude remain depressed.

    Directory of Open Access Journals (Sweden)

    Alberto Mendez-Villanueva

    Full Text Available The physiological equivalents of power output maintenance and recovery during repeated-sprint exercise (RSE remain to be fully elucidated. In an attempt to improve our understanding of the determinants of RSE performance we therefore aimed to determine its recovery following exhaustive exercise (which affected intramuscular and neural factors concomitantly with those of intramuscular concentrations of adenosine triphosphate [ATP], phosphocreatine [PCr] and pH values and electromyography (EMG activity (a proxy for net motor unit activity changes. Eight young men performed 10, 6-s all-out sprints on a cycle ergometer, interspersed with 30 s of recovery, followed, after 6 min of passive recovery, by five 6-s sprints, again interspersed by 30 s of passive recovery. Biopsies of the vastus lateralis were obtained at rest, immediately after the first 10 sprints and after 6 min of recovery. EMG activity of the vastus lateralis was obtained from surface electrodes throughout exercise. Total work (TW, [ATP], [PCr], pH and EMG amplitude decreased significantly throughout the first ten sprints (P<0.05. After 6 min of recovery, TW during sprint 11 recovered to 86.3±7.7% of sprint 1. ATP and PCr were resynthesized to 92.6±6.0% and 85.3±10.3% of the resting value, respectively, but muscle pH and EMG amplitude remained depressed. PCr resynthesis was correlated with TW done in sprint 11 (r = 0.79, P<0.05 and TW done during sprints 11 to 15 (r = 0.67, P<0.05. There was a ∼2-fold greater decrease in the TW/EMG ratio in the last five sprints (sprint 11 to 15 than in the first five sprints (sprint 1 to 5 resulting in a disproportionate decrease in mechanical power (i.e., TW in relation to EMG. Thus, we conclude that the inability to produce power output during repeated sprints is mostly mediated by intramuscular fatigue signals probably related with the control of PCr metabolism.

  10. Intensive Versus Standard Blood Pressure Control in SPRINT-Eligible Participants of ACCORD-BP.

    Science.gov (United States)

    Buckley, Leo F; Dixon, Dave L; Wohlford, George F; Wijesinghe, Dayanjan S; Baker, William L; Van Tassell, Benjamin W

    2017-12-01

    We sought to determine the effect of intensive blood pressure (BP) control on cardiovascular outcomes in participants with type 2 diabetes mellitus (T2DM) and additional risk factors for cardiovascular disease (CVD). This study was a post hoc, multivariate, subgroup analysis of ACCORD-BP (Action to Control Cardiovascular Risk in Diabetes Blood Pressure) participants. Participants were eligible for the analysis if they were in the standard glucose control arm of ACCORD-BP and also had the additional CVD risk factors required for SPRINT (Systolic Blood Pressure Intervention Trial) eligibility. We used a Cox proportional hazards regression model to compare the effect of intensive versus standard BP control on CVD outcomes. The "SPRINT-eligible" ACCORD-BP participants were pooled with SPRINT participants to determine whether the effects of intensive BP control interacted with T2DM. The mean baseline Framingham 10-year CVD risk scores were 14.5% and 14.8%, respectively, in the intensive and standard BP control groups. The mean achieved systolic BP values were 120 and 134 mmHg in the intensive and standard BP control groups ( P control reduced the composite of CVD death, nonfatal myocardial infarction (MI), nonfatal stroke, any revascularization, and heart failure (hazard ratio 0.79; 95% CI 0.65-0.96; P = 0.02). Intensive BP control also reduced CVD death, nonfatal MI, and nonfatal stroke (hazard ratio 0.69; 95% CI 0.51-0.93; P = 0.01). Treatment-related adverse events occurred more frequently in participants receiving intensive BP control (4.1% vs. 2.1%; P = 0.003). The effect of intensive BP control on CVD outcomes did not differ between patients with and without T2DM ( P > 0.62). Intensive BP control reduced CVD outcomes in a cohort of participants with T2DM and additional CVD risk factors. © 2017 by the American Diabetes Association.

  11. One hundred and fifty years of sprint and distance running – Past trends and future prospects

    Science.gov (United States)

    Weiss, Martin; Newman, Alexandra; Whitmore, Ceri; Weiss, Stephan

    2016-01-01

    Abstract Sprint and distance running have experienced remarkable performance improvements over the past century. Attempts to forecast running performances share an almost similarly long history but have relied so far on relatively short data series. Here, we compile a comprehensive set of season-best performances for eight Olympically contested running events. With this data set, we conduct (1) an exponential time series analysis and (2) a power-law experience curve analysis to quantify the rate of past performance improvements and to forecast future performances until the year 2100. We find that the sprint and distance running performances of women and men improve exponentially with time and converge at yearly rates of 4% ± 3% and 2% ± 2%, respectively, towards their asymptotic limits. Running performances can also be modelled with the experience curve approach, yielding learning rates of 3% ± 1% and 6% ± 2% for the women's and men's events, respectively. Long-term trends suggest that: (1) women will continue to run 10–20% slower than men, (2) 9.50 s over 100 m dash may only be broken at the end of this century and (3) several middle- and long-distance records may be broken within the next two to three decades. The prospects of witnessing a sub-2 hour marathon before 2100 remain inconclusive. Our results should be interpreted cautiously as forecasting human behaviour is intrinsically uncertain. The future season-best sprint and distance running performances will continue to scatter around the trends identified here and may yield unexpected improvements of standing world records. PMID:26088705

  12. Six Sessions of Sprint Interval Training Improves Running Performance in Trained Athletes.

    Science.gov (United States)

    Koral, Jerome; Oranchuk, Dustin J; Herrera, Roberto; Millet, Guillaume Y

    2018-03-01

    Koral, J, Oranchuk, DJ, Herrera, R, and Millet, GY. Six sessions of sprint interval training improves running performance in trained athletes. J Strength Cond Res 32(3): 617-623, 2018-Sprint interval training (SIT) is gaining popularity with endurance athletes. Various studies have shown that SIT allows for similar or greater endurance, strength, and power performance improvements than traditional endurance training but demands less time and volume. One of the main limitations in SIT research is that most studies were performed in a laboratory using expensive treadmills or ergometers. The aim of this study was to assess the performance effects of a novel short-term and highly accessible training protocol based on maximal shuttle runs in the field (SIT-F). Sixteen (12 male, 4 female) trained trail runners completed a 2-week procedure consisting of 4-7 bouts of 30 seconds at maximal intensity interspersed by 4 minutes of recovery, 3 times a week. Maximal aerobic speed (MAS), time to exhaustion at 90% of MAS before test (Tmax at 90% MAS), and 3,000-m time trial (TT3000m) were evaluated before and after training. Data were analyzed using a paired samples t-test, and Cohen's (d) effect sizes were calculated. Maximal aerobic speed improved by 2.3% (p = 0.01, d = 0.22), whereas peak power (PP) and mean power (MP) increased by 2.4% (p = 0.009, d = 0.33) and 2.8% (p = 0.002, d = 0.41), respectively. TT3000m was 6% shorter (p training in the field significantly improved the 3,000-m run, time to exhaustion, PP, and MP in trained trail runners. Sprint interval training in the field is a time-efficient and cost-free means of improving both endurance and power performance in trained athletes.

  13. Maturation-related adaptations in running speed in response to sprint training in youth soccer players.

    Science.gov (United States)

    Moran, Jason; Parry, Dave A; Lewis, Ieuan; Collison, Jay; Rumpf, Michael C; Sandercock, Gavin R H

    2018-05-01

    This study investigated the effects of a previously recommended dose of sprint training (ST) in young male soccer players of differing maturity status. Quasi-experimental design. Male soccer players from two professional academies were divided into Pre-PHV (Training: n=12; Control: n=13) and Mid-PHV (Training: n=7; Control=10) groups. The training groups completed 16 sprints of 20m with 90s recovery, once per week for 8weeks. Between-group effect sizes (ES) were substantially larger in Pre-PHV (10m [1.54, CI: 0.74-2.23]; 20m [1.49, CI: 0.75-2.23]; 5-10-5 [0.92, CI: 0.23-1.61]) than in Mid-PHV (10m [-0.00, CI: -0.81 to 0.81]; 20m [-0.12, CI: -0.93 to 0.69]; 5-10-5 [-0.41, CI: -1.22 to 0.41]). Within-group effects demonstrated a similar, though less accentuated, trend which revealed ST to be effective in both Pre-PHV (10m [0.44, CI: -0.24 to 1.12]; 20m [0.45, CI: -0.23 to 1.13]; 5-10-5 [0.69, CI: 0.00-1.38]) and Mid-PHV (10m [0.51, CI: -0.38 to 1.40]; 20m [0.33, CI: -0.56 to 1.21]; 5-10-5 [0.43, CI: -0.46 to 1.32]). ST, in the amount of 16 sprints over 20m with a 90s rest, may be more effective in Pre-PHV youths than in Mid-PHV youths. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  14. Effects of synchronous versus asynchronous mode of propulsion on wheelchair basketball sprinting.

    Science.gov (United States)

    Faupin, Arnaud; Borel, Benoit; Meyer, Christophe; Gorce, Philippe; Watelain, Eric

    2013-11-01

    This study aimed to first investigate synchronous (SYN) versus asynchronous (ASY) mode of propulsion and, second, investigate the wheel camber effects on sprinting performance as well as temporal parameters. Seven wheelchair basketball players performed four maximal eight-second sprints on a wheelchair ergometer. They repeated the test according to two modes of propulsion (SYN and ASY) and two wheel cambers (9° and 15°). The mean maximal velocity and push power output was greater in the synchronous mode compared to the asynchronous mode for both camber angles. However, the fluctuation in the velocity profile is inferior for ASY versus SYN mode for both camber angles. Greater push time/cycle time (Pt/Ct) and arm frequency (AF) for synchronous mode versus asynchronous mode and inversely, lesser Ct and rest time (Rt) values for the synchronous mode, for which greater velocity were observed. SYN mode leads to better performance than ASY mode in terms of maximal propulsion velocity. However, ASY propulsion allows greater continuity of the hand-rim force application, reducing fluctuations in the velocity profile. The camber angle had no effect on ASY and SYN mean maximal velocity and push power output. The study of wheelchair propulsion strategies is important for better understanding physiological and biomechanical impacts of wheelchair propulsion for individuals with disabilities. From a kinematical point of view, this study highlights synchronous mode of propulsion to be more efficient, with regards to mean maximal velocity reaching during maximal sprinting exercises. Even if this study focuses on well-trained wheelchair athletes, results from this study could complement the knowledge on the physiological and biomechanical adaptations to wheelchair propulsion and therefore, might be interesting for wheelchair modifications for purposes of rehabilitation.

  15. Evaluating Junior Secondary Science Textbook Usage in Australian Schools

    Science.gov (United States)

    McDonald, Christine V.

    2016-08-01

    A large body of research has drawn attention to the importance of providing engaging learning experiences in junior secondary science classes, in an attempt to attract more students into post-compulsory science courses. The reality of time and resource constraints, and the high proportion of non-specialist science teachers teaching science, has resulted in an overreliance on more transmissive pedagogical tools, such as textbooks. This study sought to evaluate the usage of junior secondary science textbooks in Australian schools. Data were collected via surveys from 486 schools teaching junior secondary (years 7-10), representing all Australian states and territories. Results indicated that most Australian schools use a science textbook in the junior secondary years, and textbooks are used in the majority of science lessons. The most highly cited reason influencing choice of textbook was layout/colour/illustrations, and electronic technologies were found to be the dominant curricula material utilised, in addition to textbooks, in junior secondary science classes. Interestingly, the majority of respondents expressed high levels of satisfaction with their textbooks, although many were keen to stress the subsidiary role of textbooks in the classroom, emphasising the textbook was `one' component of their teaching repertoire. Importantly, respondents were also keen to stress the benefits of textbooks in supporting substitute teachers, beginning teachers, and non-specialist science teachers; in addition to facilitating continuity of programming and staff support in schools with high staff turnover. Implications from this study highlight the need for high quality textbooks to support teaching and learning in Australian junior secondary science classes.

  16. Changes in Muscle and Cerebral Deoxygenation and Perfusion during Repeated Sprints in Hypoxia to Exhaustion

    Directory of Open Access Journals (Sweden)

    Sarah J. Willis

    2017-10-01

    Full Text Available During supramaximal exercise, exacerbated at exhaustion and in hypoxia, the circulatory system is challenged to facilitate oxygen delivery to working tissues through cerebral autoregulation which influences fatigue development and muscle performance. The aim of the study was to evaluate the effects of different levels of normobaric hypoxia on the changes in peripheral and cerebral oxygenation and performance during repeated sprints to exhaustion. Eleven recreationally active participants (six men and five women; 26.7 ± 4.2 years, 68.0 ± 14.0 kg, 172 ± 12 cm, 14.1 ± 4.7% body fat completed three randomized testing visits in conditions of simulated altitude near sea-level (~380 m, FIO2 20.9%, ~2000 m (FIO2 16.5 ± 0.4%, and ~3800 m (FIO2 13.3 ± 0.4%. Each session began with a 12-min warm-up followed by two 10-s sprints and the repeated cycling sprint (10-s sprint: 20-s recovery test to exhaustion. Measurements included power output, vastus lateralis, and prefrontal deoxygenation [near-infrared spectroscopy, delta (Δ corresponds to the difference between maximal and minimal values], oxygen uptake, femoral artery blood flow (Doppler ultrasound, hemodynamic variables (transthoracic impedance, blood lactate concentration, and rating of perceived exertion. Performance (total work, kJ; −27.1 ± 25.8% at 2000 m, p < 0.01 and −49.4 ± 19.3% at 3800 m, p < 0.001 and pulse oxygen saturation (−7.5 ± 6.0%, p < 0.05 and −18.4 ± 5.3%, p < 0.001, respectively decreased with hypoxia, when compared to 400 m. Muscle Δ hemoglobin difference ([Hbdiff] and Δ tissue saturation index (TSI were lower (p < 0.01 at 3800 m than at 2000 and 400 m, and lower Δ deoxyhemoglobin resulted at 3800 m compared with 2000 m. There were reduced changes in peripheral [Δ[Hbdiff], ΔTSI, Δ total hemoglobin ([tHb

  17. Análisis de los factores de rendimiento en triatlón distancia sprint

    OpenAIRE

    Cejuela Anta, Roberto; Pérez Turpin, José Antonio; Villa Vicente, José Gerardo; Cortell-Tormo, Juan M.; Rodríguez Marroyo, José Antonio

    2007-01-01

    El triatlón es un deporte combinado y de resistencia donde se desarrollan sin solución de continuidad natación, ciclismo y carrera a pie, siempre en ese orden y sin parar el cronometro. La distancia Sprint es la más corta según el reglamento y sobre la cual se disputan mayor número de pruebas (0’750 km, 20 km, 5 km). Determinar los factores de rendimiento es fundamental para optimizar el entrenamiento de una modalidad deportiva. La diversidad de distancias en este deporte, obliga a realizar d...

  18. The acute effects of heavy back and front squats on speed during forty-meter sprint trials.

    Science.gov (United States)

    Yetter, Mike; Moir, Gavin L

    2008-01-01

    The purpose of the present study was to investigate the effects of performing heavy back squats (HBS) and heavy front squats (HFS) on the average speed during each 10-m interval of 40-m sprint trials. In a randomized, cross-over design, 10 strength-trained men performed a HBS, HFS, or control treatment before performing three 40-m sprint trials separated by 3 minutes. The HBS and HFS treatments consisted of performing parallel back or front squats with 30%, 50%, and 70% of the subject's 1 repetition maximum after 5 minutes of cycling. The control treatment consisted of cycling for 5 minutes. The sprint trials were performed 4 minutes after completing the HBS, HFS, or control treatments. Significant increases in speed were found during the 10- to 20-m interval for the HBS compared with the control treatment (mean difference, 0.12 m x s(-1); 95% likely range, 0.05-0.18 m x s(-1); P = 0.001). During the 30- to 40-m interval, HBS produced significantly greater speeds compared with the HFS treatment (mean difference, 0.24 m x s(-1); 95% likely range, 0.02-0.45 m x s(-1); P = 0.034) and the control treatment (mean difference, 0.18 m x s(-1); 95% likely range, 0.03-0.32 m x s(-1); P = 0.021). The differing effects of the treatments may reflect different levels of muscular activation or different mechanical aspects of the squat exercises. Similarly, the multidimensional nature of sprint running means that other specific exercises may confer improvements in sprinting performance during other intervals. It is suggested that coaches could incorporate HBS into the warm-up procedure of athletes to improve sprinting performance.

  19. Repeated high-speed activities during youth soccer games in relation to changes in maximal sprinting and aerobic speeds.

    Science.gov (United States)

    Buchheit, M; Simpson, B M; Mendez-Villanueva, A

    2013-01-01

    The aim of this study was to examine in highly-trained young soccer players whether substantial changes in either maximal sprinting speed (MSS) or maximal aerobic speed (as inferred from peak incremental test speed, V(Vam-Eval)) can affect repeated high-intensity running during games. Data from 33 players (14.5±1.3 years), who presented substantial changes in either MSS or V(Vam-Eval) throughout 2 consecutive testing periods (~3 months) were included in the final analysis. For each player, time-motion analyses were performed using a global positioning system (1-Hz) during 2-10 international club games played within 1-2 months from/to each testing period of interest (n for game analyzed=109, player-games=393, games per player per period=4±2). Sprint activities were defined as at least a 1-s run at intensities higher than 61% of individual MSS. Repeated-sprint sequences (RSS) were defined as a minimum of 2 consecutive sprints interspersed with a maximum of 60 s of recovery. Improvements in both MSS and V(Vam-Eval) were likely associated with a decreased RSS occurrence, but in some positions only (e. g., - 24% vs. - 3% for improvements in MSS in strikers vs. midfielders, respectively). The changes in the number of sprints per RSS were less clear but also position-dependent, e. g., +7 to +12% for full-backs and wingers, - 5 to - 7% for centre-backs and midfielders. In developing soccer players, changes in repeated-sprint activity during games do not necessarily match those in physical fitness. Game tactical and strategic requirements are likely to modulate on-field players' activity patterns independently (at least partially) of players' physical capacities. © Georg Thieme Verlag KG Stuttgart · New York.

  20. Repeated Sprint Ability in Elite Water Polo Players and Swimmers and its Relationship to Aerobic and Anaerobic Performance

    Directory of Open Access Journals (Sweden)

    Yoav Meckel

    2013-12-01

    Full Text Available The purpose of this study was to determine indices of swimming repeated sprint ability (RSA in 19 elite water polo players compared to 16 elite swimmers during a repeated sprint swimming test (RST, and to examine the relationships between these indices and aerobic and anaerobic performance capabilities in both groups. Indices of RSA were determined by the ideal sprint time (IS, the total sprint time (TS, and the performance decrement (PD recorded during an 8 x 15-m swimming RST. Single long - (800-m and short-(25-m distance swim tests were used to determined indices of aerobic and anaerobic swimming capabilities, respectively. The water polo players exhibited lower RSA swimming indices, as well as lower scores in the single short and long swim distances, compared to the swimmers. Significant relationships were found between the 25- m swim results and the IS and the TS, but not the PD of both the swimmers and the water polo players. No significant relationships were found between the 800-m swim results and any of the RSA indices in either the swimmers or the water polo players. No significant relationships were found between the 25-m and the 800-m swim results in either the swimmers or the water polo players. The results indicate that swimmers posses better RSA as well as higher anaerobic and aerobic capabilities, as reflected by the single short- and long-distance swim tests, compared to water polo players. The results also indicate that, as for running and cycling, repeated sprint swim performance is strongly related to single sprint performance.

  1. The roles of games in teaching and learning of mathematics in junior ...

    African Journals Online (AJOL)

    The roles of games in teaching and learning of mathematics in junior secondary schools. ... The research seeks to enhance the status of games in teaching mathematics in junior secondary schools curriculum ... AJOL African Journals Online.

  2. Marketing advisors and their role for junior gas producers

    International Nuclear Information System (INIS)

    Maffitt, D.W.

    1997-01-01

    The role of marketing advisors in the new deregulated natural gas industry was discussed. These producer-oriented marketing consultants are specialists in providing affordable marketing services to junior gas producers on an 'as-needed' basis. The most important service provided by marketing advisors is helping the client identify management problems, analyze such problems and recommend solutions. Accordingly, the marketing advisor should be independent and objective, with no conflict of interests. He/she should be prepared to invest a lot of time and effort in providing the junior producer with a customized diagnosis of its marketing problems. 5 refs., 3 figs

  3. Marketing advisors and their role for junior gas producers

    Energy Technology Data Exchange (ETDEWEB)

    Maffitt, D.W. [Phoenix Gas Marketing Consultants Inc., Calgary, AB (Canada)

    1997-05-01

    The role of marketing advisors in the new deregulated natural gas industry was discussed. These producer-oriented marketing consultants are specialists in providing affordable marketing services to junior gas producers on an `as-needed` basis. The most important service provided by marketing advisors is helping the client identify management problems, analyze such problems and recommend solutions. Accordingly, the marketing advisor should be independent and objective, with no conflict of interests. He/she should be prepared to invest a lot of time and effort in providing the junior producer with a customized diagnosis of its marketing problems. 5 refs., 3 figs.

  4. Muscle power and repeated sprint ability in soccer players DOI: 10.5007/1980-0037.2010v12n4p255

    Directory of Open Access Journals (Sweden)

    Juliano Dal Pupo

    2010-01-01

    Full Text Available Muscle power is one of the most important physical qualities of soccer player performance and needs to be maintained during a match. Thus, the aim of this study was to investigate the levels of muscle power in soccer players before and after performing repeated sprints (RS, and the association between power and RS performance. Twenty soccer players from the under-20 category aged 18-20 years participated in this study. The study consisted of the execution of vertical jumps, execution of RS, new execution of vertical jumps, and collection of blood samples. The continuous jump (CJ test was performed on a piezoelectric force platform for the measurement of muscle power and the RAST test was used to evaluate RS ability. No significant difference in the levels of muscle power was observed after RS (p=0.57. Significant differences were observed in the first to fifth sprint times (p< 0.01, but not between the fifth and sixth sprint (p=0.06. CJ height before RS was correlated with first sprint time (r=-0.62, p< 0.01, best sprint time (r=-0.60, p< 0.01, and average sprint time (r= -0.54, p<0.01. In conclusion, the soccer players studied showed no significant reduction in muscle power after RS. A decrease in performance was observed from the first to the fifth sprint, but not between the fifth and sixth sprint. The muscle power of soccer players was a determinant factor to perform one maximum sprint, as well as successive sprints.

  5. Effect of small sided handball game on aerobic capacity and repeated sprint ability of male handball players

    OpenAIRE

    CHITTIBABU, Balasubramanian

    2014-01-01

    The purpose of this study was to determine the effects of four and eight weeks small-sided handball game on aerobic capacity and repeated sprint ability of male handball players. Sixteen (16) male university handball players volunteered to act as subjects and were randomly assigned to small-sided handball game group (SSHG) and control group (CG).  Small-sided handball game was administered three days in a week for eight weeks. Subjects were measured on aerobic capacity, total sprint time and ...

  6. TO COMPARE THE EFFECTS OF SPRINT AND PLYOMETRIC TRAINING PROGRAM ON ANAEROBIC POWER AND AGILITY IN COLLEGIATE MALE FOOTBALL PLAYERS

    Directory of Open Access Journals (Sweden)

    K. Vadivelan

    2015-06-01

    Full Text Available Background: Football is the world’s most popular game and is played by men, women and children of all ages and levels of ability. Success as a player requires an appropriate mixture of mental, physical, technical and tactical ability. Many decisive moments are defined by anaerobic activities such as sprinting, jumping & contests for the football. Agility is an ability of the neuromuscular system to coordinate explosive changes of direction of an individual and/or multiple body segments in all planes of motion. Plyometric Training has been advocated for sports that require the athletes to have explosive power and agility. Similarly previous sprint training studies have shown improvement in the dynamic athletic lower body performance. Advanced technique such as plyometric training protocol has proven more effective but not much studies have been done to assess its effectiveness over Plyometric Training, namely Lower Body Power and Agility Methods: A total of 30 collegiate football players were taken with a mean age of 21.5 with a standard deviation of one. They were randomized into two groups (Group A – Sprint Training & Group B – Plyometric Training. Each group consist of 15 players were selected based on their selection criteria. Informed consent was obtained from the subjects. The study was conducted for six weeks (12 sessions with both the Groups. Evolution parameters are vertical jump height, 40 yard dash, illinois agility Test. Results: Independent t test was used to analysis data. On comparing VJH, Plyometric Training shows (49.26 which have the higher mean value is more effective than Sprint Training (44.93.On comparing Anaerobic power Plyometric Training shows (4150.8 which has the higher Mean value is more effective than Sprint Training (3782.4, on comparing 40 yard dash Plyometric Training shows (5.335 which has the lower Mean value is more effective than Sprint Training (5.490. Illinois Agility Test Plyometric Training shows (15

  7. Repeated Sprint Ability in Young Basketball Players: Multi-direction vs. One-Change of Direction (Part 1)

    OpenAIRE

    Padulo, Johnny; Bragazzi, Nicola L.; Nikolaidis, Pantelis T.; Dello Iacono, Antonio; Attene, Giuseppe; Pizzolato, Fabio; Dal Pupo, Juliano; Zagatto, Alessandro M.; Oggianu, Marcello; Migliaccio, Gian M.

    2016-01-01

    The aim of the present study was to examine the reliability of a novel multi-direction repeated sprint ability test (RSM; 10×(6×5-m)) compared with a repeated sprint ability test (RSA) with one change of direction (10×(2×15-m)), and the relationship of the RSM and RSA with Yo-Yo intermittent recovery test level 1 (Yo-Yo IR1) and jump performances [squat jump (SJ) and counter-movement-jump (CMJ)]. Thirty-six (male, n=14, female n=22) young basketball players (age 16.0±0.9 yrs) performed the RS...

  8. Determinants of a simulated cross-country skiing sprint competition using V2 skating technique on roller skis.

    Science.gov (United States)

    Mikkola, Jussi; Laaksonen, Marko; Holmberg, Hans-Christer; Vesterinen, Ville; Nummela, Ari

    2010-04-01

    The present study investigated the performance-predicting factors of a simulated cross-country (XC) skiing sprint competition on roller skis, on a slow surface. Sixteen elite male XC skiers performed a simulated sprint competition (4 x 850 m heat with a 20-minute recovery) using V2 skating technique on an indoor tartan track. Heat velocities, oxygen consumption, and peak lactate were measured during or after the heats. Maximal skiing velocity was measured by performing a 30-m speed test. Explosive and maximal force production in the upper body was determined by bench press (BP). Subjects also performed maximal anaerobic skiing test (MAST) and the 2 x 2-km double poling (DP) test. The maximal velocity of MAST (VMAST) and velocities at 3 (V3), 5 (V5), 7 (V7) mmol.L lactate levels in MAST were determined. In the 2 x 2-km test, DP economy (VO2SUBDP) and maximal 2-km DP velocity (VDP2KM) were determined. The best single performance-predicting factors for the sprint performance were VDP2KM (r = 0.73, p < 0.01), V7 (r = 0.70, p < 0.01), and VO2SUBDP (r = -0.70, p < 0.01). Faster skiers in sprint simulation had a higher absolute VO2 (L.min) (p < 0.05-0.01) during sprint heats, and higher anaerobic skiing power (VMAST, p < 0.05) and better anaerobic skiing economy (V3, V5, V7, p < 0.05-0.001) than slower skiers. Faster skiers were also stronger in BP, with regard to both absolute (p < 0.01) and relative (p < 0.05) values. In addition, anaerobic characteristics seem to be of importance at the beginning of the XC skiing sprint competition, whereas the aerobic characteristics become more important as the XC skiing sprint competition progressed. This study indicates that sprint skiers should emphasize sport-specific upper body training, and training skiing economy at high speeds.

  9. Solar building

    OpenAIRE

    Zhang, Luxin

    2014-01-01

    In my thesis I describe the utilization of solar energy and solar energy with building integration. In introduction it is also mentioned how the solar building works, trying to make more people understand and accept the solar building. The thesis introduces different types of solar heat collectors. I compared the difference two operation modes of solar water heating system and created examples of solar water system selection. I also introduced other solar building applications. It is conv...

  10. Solar energy

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This chapter discusses the role solar energy may have in the energy future of the US. The topics discussed in the chapter include the solar resource, solar architecture including passive solar design and solar collectors, solar-thermal concentrating systems including parabolic troughs and dishes and central receivers, photovoltaic cells including photovoltaic systems for home use, and environmental, health and safety issues

  11. Mechanical power, thrust power and propelling efficiency: relationships with elite sprint swimming performance.

    Science.gov (United States)

    Gatta, Giorgio; Cortesi, Matteo; Swaine, Ian; Zamparo, Paola

    2018-03-01

    The purpose of this study was to explore the relationships between mechanical power, thrust power, propelling efficiency and sprint performance in elite swimmers. Mechanical power was measured in 12 elite sprint male swimmers: (1) in the laboratory, by using a whole-body swimming ergometer (W' TOT ) and (2) in the pool, by measuring full tethered swimming force (F T ) and maximal swimming velocity (V max ): W' T  = F T  · V max . Propelling efficiency (η P ) was estimated based on the "paddle wheel model" at V max . V max was 2.17 ± 0.06 m · s -1 , η P was 0.39 ± 0.02, W' T was 374 ± 62 W and W' TOT was 941 ± 92 W. V max was better related to W' T (useful power output: R = 0.943, P swimming performance. The ratio W' T /W' TOT (0.40 ± 0.04) represents the fraction of total mechanical power that can be utilised in water (e.g., η P ) and was indeed the same as that estimated based on the "paddle wheel model"; this supports the use of this model to estimate η P in swimming.

  12. Jump Squat is More Related to Sprinting and Jumping Abilities than Olympic Push Press.

    Science.gov (United States)

    Loturco, I; Kobal, R; Maldonado, T; Piazzi, A F; Bottino, A; Kitamura, K; Abad, C C C; Pereira, L A; Nakamura, F Y

    2017-07-01

    The aim of this study was to test the relationships between jump squat (JS) and Olympic push press (OPP) power outputs and performance in sprint, squat jump (SJ), countermovement jump (CMJ) and change of direction (COD) speed tests in elite soccer players. 27 athletes performed a maximum power load test to determine their bar mean propulsive power (MPP) and bar mean propulsive velocity (MPV) in the JS and OPP exercises. Magnitude-based inference was used to compare the exercises. The MPV was almost certainly higher in the OPP than in the JS. The MPP relative to body mass (MPP REL) was possibly higher in the OPP. Only the JS MPP REL presented very large correlations with linear speed ( r> 0.7, for speed in 5, 10, 20 and 30 m) and vertical jumping abilities ( r> 0.8, for SJ and CMJ), and moderate correlation with COD speed ( r= 0.45). Although significant (except for COD), the associations between OPP outcomes and field-based measurements (speed, SJ and CMJ) were all moderate, ranging from 0.40 to 0.48. In a group composed of elite soccer players, the JS exercise is more associated with jumping and sprinting abilities than the OPP. Longitudinal studies are needed to confirm if these strong relationships imply superior training effects in favor of the JS exercise. © Georg Thieme Verlag KG Stuttgart · New York.

  13. Dietary Acid-Base Balance in Adolescent Sprint Athletes: A Follow-up Study

    Directory of Open Access Journals (Sweden)

    Peter Clarys

    2011-02-01

    Full Text Available Sprinters are advised to include additional protein sources in their diet. Basal metabolism and vigorous physical activities generate hydrogen ions that need to be buffered. The present follow-up study estimates the dietary potential renal acid load (PRAL and net endogenous acid production (NEAP in adolescent sprint athletes. Seven-day food diaries and anthropometrics of 60 adolescent sprint athletes (mean age at start 14.7 ± 1.9 years were collected every six months over a three year period. Comparisons were made between athletes with a negative (PRAL(− versus positive PRAL (PRAL(+. For the entire sample, mean PRAL values of up to 6 mEq/day were slightly positive despite a relatively high protein intake of around 1.5 g/kg. The NEAP ranging between 42 and 46 mEq/day remained stable during the study period. Athletes with a PRAL(− (−8 to −10 mEq/day consumed significantly more fruit and fruit juice than athletes with a PRAL(+ (+9 to 14 mEq/day. Athletes with a PRAL(+ did not consume more meat, fish and poultry than athletes with a PRAL(−. Grains and dairy products were only discriminative between the two groups on one measurement occasion. Lowering the PRAL can be obtained by increasing the consumption of potatoes, fruits, vegetables and vegetable soup.

  14. Gender differences in the physiological responses and kinematic behaviour of elite sprint cross-country skiers.

    Science.gov (United States)

    Sandbakk, Oyvind; Ettema, Gertjan; Leirdal, Stig; Holmberg, Hans-Christer

    2012-03-01

    Gender differences in performance by elite endurance athletes, including runners, track cyclists and speed skaters, have been shown to be approximately 12%. The present study was designed to examine gender differences in physiological responses and kinematics associated with sprint cross-country skiing. Eight male and eight female elite sprint cross-country skiers, matched for performance, carried out a submaximal test, a test of maximal aerobic capacity (VO(2max)) and a shorter test of maximal treadmill speed (V (max)) during treadmill roller skiing utilizing the G3 skating technique. The men attained 17% higher speeds during both the VO(2max) and the V (max) tests (P differences that were reduced to 9% upon normalization for fat-free body mass. Furthermore, the men exhibited 14 and 7% higher VO(2max) relative to total and fat-free body mass, respectively (P gender groups. At the same absolute speed, men employed 11% longer cycles at lower rates, and at peak speed, 21% longer cycle lengths (P gender differences in performance and VO(2max) than those reported for comparable endurance sports. These differences reflect primarily the higher VO(2max) and lower percentage of body fat in men, since no gender differences in the ability to convert metabolic rate into work rate and speed were observed. With regards to kinematics, the gender difference in performance was explained by cycle length, not by cycle rate.

  15. Low dose creatine supplementation enhances sprint phase of 400 meters swimming performance.

    Science.gov (United States)

    Anomasiri, Wilai; Sanguanrungsirikul, Sompol; Saichandee, Pisut

    2004-09-01

    This study demonstrated the effect of low dose creatine supplement (10 g. per day) on the sprinting time in the last 50 meters of 400 meters swimming competition, as well as the effect on exertion. Nineteen swimmers in the experimental group received creatine monohydrate 5 g with orange solution 15 g, twice per day for 7 days and nineteen swimmers in the control group received the same quantity of orange solution. The results showed that the swimmers who received creatine supplement lessened the sprinting time in the last 50 meters of 400 meters swimming competition than the control group. (p<0.05). The results of Wingate test (anaerobic power, anaerobic capacity and fatigue index) compared between pre and post supplementation. There was significant difference at p<0.05 in the control group from training effect whereas there was significant difference at p<0.000 from training effect and creatine supplement in the experiment group. Therefore, the creatine supplement in amateur swimmers in the present study enhanced the physical performance up to the maximum capacity.

  16. Fatigue and changes of ATP, creatine phosphate, and lactate during the 400-m sprint.

    Science.gov (United States)

    Hirvonen, J; Nummela, A; Rusko, H; Rehunen, S; Härkönen, M

    1992-06-01

    Fatigue during the 400-m sprint was studied by measuring muscle ATP, creatine phosphate (CP), lactate (M-La), and blood lactate (B-La) in six male runners before and after four experimental sprints (100, 200, 300, and 400 m). During the first 100 m, muscle CP decreased from 15.8 +/- 1.7 to 8.3 +/- 0.3 mmol/kg while M-La increased to 3.6 +/- 0.4 mmol/kg. After 200 m the CP had decreased to 6.5 +/- 0.5 mmol/kg and M-La had increased to 8.3 +/- 1.1 mmol/kg. At the end of the 400 meters, ATP and CP concentrations had decreased by 27% and 89%, respectively, and M-La had increased to 17.3 +/- 0.9 mmol/kg. It was concluded that after 200 m the speed of running decreased, although CP was not depleted and lactate concentration was not at maximum level. Complete fatigue occurred when CP stores were depleted and B-La and M-La attained an individual maximum.

  17. On the Importance of "Front-Side Mechanics" in Athletics Sprinting.

    Science.gov (United States)

    Haugen, Thomas; Danielsen, Jørgen; Alnes, Leif Olav; McGhie, David; Sandbakk, Øyvind; Ettema, Gertjan

    2018-05-16

    Practitioners have, for many years, argued that athletic sprinters should optimize front-side mechanics (leg motions occurring in front of the extended line through the torso) and minimize back-side mechanics. This study aimed to investigate if variables related to front- and back-side mechanics can be distinguished from other previously highlighted kinematic variables (spatiotemporal variables and variables related to segment configuration and velocities at touchdown) in how they statistically predict performance. A total of 24 competitive sprinters (age: 23.1 [3.4] y, height: 1.81 [0.06] m, body mass: 75.7 [5.6] kg, and 100-m personal best: 10.86 [0.22] s) performed two 20-m starts from block and 2 to 3 flying sprints over 20 m. Kinematics were recorded in 3D using a motion tracking system with 21 cameras at a 250 Hz sampling rate. Several front- and back-side variables, including thigh (r = .64) and knee angle (r = .51) at lift-off and maximal thigh extension (r = .66), were largely correlated (P mechanics were crucial for sprint performance among the investigated sprinters.

  18. Recovery of voluntary and evoked muscle performance following intermittent-sprint exercise in the heat.

    Science.gov (United States)

    Duffield, Rob; King, Monique; Skein, Melissa

    2009-06-01

    This study investigated the effects of hot conditions on the acute recovery of voluntary and evoked muscle performance and physiological responses following intermittent exercise. Seven youth male and six female team-sport athletes performed two sessions separated by 7 d, involving a 30-min exercise protocol and 60-min passive recovery in either 22 degrees C or 33 degrees C and 40% relative humidity. The exercise protocol involved a 20-s maximal sprint every 5 min, separated by constant-intensity exercise at 100 W on a cycle ergometer. Maximal voluntary contraction (MVC) and a resting evoked twitch (Pf) of the right knee extensors were assessed before and immediately following exercise and again 15, 30, and 60 min postexercise, and capillary blood was obtained at the same time points to measure lactate, pH, and HCO3. During and following exercise, core temperature, heart rate and rating of perceived exertion (RPE) were also measured. No differences (P=0.73 to 0.95) in peak power during repeated sprints were present between conditions. Postexercise MVC was reduced (Pheat (83+/-10 vs 74+/-11% recovered). Both heart rate and core temperature were significantly higher (Precovery in the heat. Capillary blood values did not differ between conditions at any time point, whereas sessional RPE was higher 60 min postexercise in the heat. The current data suggests that passive recovery in warm temperatures not only delays cardiovascular and thermal recovery, but may also slow the recovery of MVC and RPE.

  19. Relationship between Lower Limb Angular Kinematic Variables and the Effectiveness of Sprinting during the Acceleration Phase

    Directory of Open Access Journals (Sweden)

    Artur Struzik

    2016-01-01

    Full Text Available The ability to reach a high running velocity over a short distance is essential to a high playing performance in team games. The aim of this study was to determine the relationship between running time over a 10-meter section of a 30-meter sprint along a straight line and changes in the angle and angular velocity that were observed in the ankle, knee, and hip joints. The possible presence may help to optimize motion efficiency during acceleration sprint phase. Eighteen girls involved in team sports were examined in the study. The Fusion Smart Speed System was employed for running time measurements. The kinematic data were recorded using the Noraxon MyoMotion system. Statistically significant relationships were found between running time over a 10-meter section and the kinematic variables of hip and ankle joints. An excessively large flexion in hip joints might have an unfavorable effect on running time during the acceleration phase. Furthermore, in order to minimize running time during the acceleration phase, stride should be maintained along a line (a straight line rather than from side to side. It is also necessary to ensure an adequate range of motion in the hip and ankle joints with respect to the sagittal axis.

  20. Relationship between Lower Limb Angular Kinematic Variables and the Effectiveness of Sprinting during the Acceleration Phase.

    Science.gov (United States)

    Struzik, Artur; Konieczny, Grzegorz; Stawarz, Mateusz; Grzesik, Kamila; Winiarski, Sławomir; Rokita, Andrzej

    2016-01-01

    The ability to reach a high running velocity over a short distance is essential to a high playing performance in team games. The aim of this study was to determine the relationship between running time over a 10-meter section of a 30-meter sprint along a straight line and changes in the angle and angular velocity that were observed in the ankle, knee, and hip joints. The possible presence may help to optimize motion efficiency during acceleration sprint phase. Eighteen girls involved in team sports were examined in the study. The Fusion Smart Speed System was employed for running time measurements. The kinematic data were recorded using the Noraxon MyoMotion system. Statistically significant relationships were found between running time over a 10-meter section and the kinematic variables of hip and ankle joints. An excessively large flexion in hip joints might have an unfavorable effect on running time during the acceleration phase. Furthermore, in order to minimize running time during the acceleration phase, stride should be maintained along a line (a straight line) rather than from side to side. It is also necessary to ensure an adequate range of motion in the hip and ankle joints with respect to the sagittal axis.

  1. Precooling leg muscle improves intermittent sprint exercise performance in hot, humid conditions.

    Science.gov (United States)

    Castle, Paul C; Macdonald, Adam L; Philp, Andrew; Webborn, Anthony; Watt, Peter W; Maxwell, Neil S

    2006-04-01

    We used three techniques of precooling to test the hypothesis that heat strain would be alleviated, muscle temperature (Tmu) would be reduced, and as a result there would be delayed decrements in peak power output (PPO) during exercise in hot, humid conditions. Twelve male team-sport players completed four cycling intermittent sprint protocols (CISP). Each CISP consisted of twenty 2-min periods, each including 10 s of passive rest, 5 s of maximal sprint against a resistance of 7.5% body mass, and 105 s of active recovery. The CISP, preceded by 20 min of no cooling (Control), precooling via an ice vest (Vest), cold water immersion (Water), and ice packs covering the upper legs (Packs), was performed in hot, humid conditions (mean +/- SE; 33.7 +/- 0.3 degrees C, 51.6 +/- 2.2% relative humidity) in a randomized order. The rate of heat strain increase during the CISP was faster in Control than Water and Packs (P body or whole body cooling.

  2. What is the Safest Sprint Starting Position for American Football Players?

    Directory of Open Access Journals (Sweden)

    Bruno Bonnechere, Benoit Beyer, Marcel Rooze, Jan Serge Van Sint

    2014-06-01

    Full Text Available The main objective of this study was to perform a biomechanical analysis of three different sprint start patterns to determine the safest position in term of neck injury and Sport-Related Concussion (SRC. The second objective was to collect data on the learning process effect between football players and non-players. Three different sprint initial positions adopted by football players were studied (i.e., 4-, 3- and 2-point positions. Twenty five young healthy males, including 12 football players, participated to this study. A stereophotogrammetric system (i.e., Vicon was used to record motion patterns and body segments positions. Various measurements related to head and trunk orientation, and player field-of-view were obtained (e.g., head height, trunk bending, time to reach upright position, head speed (vertical direction and body speed (horizontal direction. Learning process was found to have no influence on studied parameters. Head redress is also delayed when adopting a 4-point position leading to a reduce field-of-view during the start and increasing therefore the probability of collision. Concerning the three different positions, the 4-point position seems to be the more dangerous because leading to higher kinetic energy than the 2- and 3-point start positions. This study proposes a first biomechanical approach to understand risk/benefit balance for athletes for those three different start positions. Results suggested that the 4-point position is the most risky for football players.

  3. Effects of inspiratory muscle training on respiratory function and repetitive sprint performance in wheelchair basketball players.

    Science.gov (United States)

    Goosey-Tolfrey, V; Foden, E; Perret, C; Degens, H

    2010-07-01

    There is considerable evidence that respiratory muscle training improves pulmonary function, quality of life and exercise performance in healthy athletic populations. The benefits for wheelchair athletes are less well understood. Therefore, in the present study, influence of inspiratory muscle training (IMT) on respiratory function and repetitive propulsive sprint performance in wheelchair basketball players was examined. Using a placebo-controlled design, 16 wheelchair athletes were divided to an experimental (IMT; n=8) or placebo (sham-IMT; n=8) group based on selective grouping criteria. 30 dynamic breaths were performed by the IMT group twice daily at a resistance equivalent to 50% maximum inspiratory pressure (MIP), and 60 slow breaths were performed by the sham-IMT group once a day at 15% MIP for a period of 6 weeks. In the IMT group, both MIP and maximum expiratory pressure (17% and 23%, respectively; ptraining device suggested "less breathlessness" and "less tightness in the chest during the training". Although there was no improvement in sprint performance, an improved respiratory muscle function and quality of life were reported by participants in both the IMT and sham-IMT groups.

  4. Group Versus Individual Counseling: A Junior College Study. Final Report.

    Science.gov (United States)

    Aughinbaugh, Lorine A.

    Increases in junior college enrollment, coupled with a shortage of qualified guidance personnel, have forced many colleges to rely more heavily on group than on individual counseling for students. In the fall of 1965, students entering American River College were randomly assigned to either group or individual sessions, or not assigned, and these…

  5. Multidimensional Computerized Adaptive Testing for Indonesia Junior High School Biology

    Science.gov (United States)

    Kuo, Bor-Chen; Daud, Muslem; Yang, Chih-Wei

    2015-01-01

    This paper describes a curriculum-based multidimensional computerized adaptive test that was developed for Indonesia junior high school Biology. In adherence to the Indonesian curriculum of different Biology dimensions, 300 items was constructed, and then tested to 2238 students. A multidimensional random coefficients multinomial logit model was…

  6. Plugging into Pop at the Junior High Level.

    Science.gov (United States)

    Thompson, Dick

    1979-01-01

    Describes a junior high music program in Ridgewood, New Jersey, which capitalizes on student interest in popular music through courses in rock music history, pop music choral concerts, and facilities offering modern music production and performance equipment. This article is part of a theme issue on popular music. (SJL)

  7. Empathy, Self-Esteem and Creativity among Junior Ballet Dancers.

    Science.gov (United States)

    Kalliopuska, Mirja

    This study examined the effect of the active pursuit of ballet as a hobby on personality. The study group consisted of 62 members of the junior ballet of the Finnish National Opera, ranging in age from 9 to 17 with the majority under 14. The dancers were given four self-esteem questionnaires which measured empathy, creativity, and other…

  8. The Effect of Teachers' Emotions on Chinese Junior English Learners

    Institute of Scientific and Technical Information of China (English)

    JiangLiqin

    2004-01-01

    The study intends to investigate the effect of teachers' emotions on Chinese Junior English learners. It is very common to see that in many primary schools, Chinese English teachers tend to play games with children, teach songs and the like,leading the Chinese young English beginners to the door to English world with great enthusiasm. But after children enter

  9. PROCEDURE FOR THE ESTABLISHMENT OF COMMUNITY JUNIOR COLLEGES IN ARKANSAS.

    Science.gov (United States)

    Arkansas State Commission on Coordination of Higher Educational Finance, Little Rock.

    CRITERIA FOR ESTABLISHMENT OF JUNIOR COLLEGE DISTRICTS IN ARKANSAS INCLUDE (1) A PROJECTED ENROLLMENT OF AT LEAST 300 FULL TIME EQUIVALENT STUDENTS IN THE THIRD YEAR OF OPERATION, (2) ASSESSED VALUATION ADEQUATE TO PROVIDE FROM LOCAL PROPERTY TAXES ONE-THIRD OF THE ANNUAL OPERATING COST AND THE TOTAL DEBT SERVICE REQUIREMENTS FOR CAPITAL OUTLAY,…

  10. An analysis of the performance of Black African junior provincial ...

    African Journals Online (AJOL)

    been investigated. 1. It was found that these processes were effective in increasing participation of senior black provincial players between. 1996 and 2008. There were ... players were performing at junior provincial level but have not been afforded the ..... batsmen have performed consistently well between 2004 and 2010.

  11. Women in Academic Medicine: Measuring Stereotype Threat Among Junior Faculty.

    Science.gov (United States)

    Fassiotto, Magali; Hamel, Elizabeth Otto; Ku, Manwai; Correll, Shelley; Grewal, Daisy; Lavori, Philip; Periyakoil, V J; Reiss, Allan; Sandborg, Christy; Walton, Gregory; Winkleby, Marilyn; Valantine, Hannah

    2016-03-01

    Gender stereotypes in science impede supportive environments for women. Research suggests that women's perceptions of these environments are influenced by stereotype threat (ST): anxiety faced in situations where one may be evaluated using negative stereotypes. This study developed and tested ST metrics for first time use with junior faculty in academic medicine. Under a 2012 National Institutes of Health Pathfinder Award, Stanford School of Medicine's Office of Diversity and Leadership, working with experienced clinicians, social scientists, and epidemiologists, developed and administered ST measures to a representative group of junior faculty. 174 School of Medicine junior faculty were recruited (62% women, 38% men; 75% assistant professors, 25% instructors; 50% white, 40% Asian, 10% underrepresented minority). Women reported greater susceptibility to ST than did men across all items including ST vulnerability (p gender identification (p women reported lower beliefs in advancement (p = 0.021); however, they had similar career interest and identification, felt just as connected to colleagues, and were equally likely to pursue careers outside academia (all p > 0.42). Innovative ST metrics can provide a more complete picture of academic medical center environments. While junior women faculty are susceptible to ST, they may not yet experience all of its consequences in their early careers. As such, ST metrics offer a tool for evaluating institutional initiatives to increase supportive environments for women in academic medicine.

  12. Announcement of the Diagnostics 2016 Junior Scientists Travel Award

    OpenAIRE

    2016-01-01

    With the goal of recognizing outstanding contributions to the field of medical diagnostics by early-career investigators, including assistant professors, postdoctoral students and PhD students, and assisting them in attending international conferences in 2016, early this year Diagnostics accepted nominations for the Junior Scientists Travel Award 2016.

  13. Evaluation of English Language Textbooks Used in the Junior ...

    African Journals Online (AJOL)

    This study sought to establish the readability, comprehensibility, availability and the level of integration of English language and Literature in English in the English language textbooks in use in Lagos State junior secondary schools. Three hundred students and 60 teachers were selected from 20 schools in Lagos State.

  14. An Institutional Autopsy of St. Augustine Junior College

    Science.gov (United States)

    Lumadue, Richard T.

    2009-01-01

    Institutional autopsies can teach much about why learning centers fail the test of time. St. Augustine Junior College in north Florida, the brainchild of Dr. George Apel, was begun in 1942 and ended seven years later in 1949. The purposes of the short-lived college are identified for discussion in this paper. Also identified are the reasons for…

  15. Effect of Painting Series Package on the Performances of Junior ...

    African Journals Online (AJOL)

    The study investigated the effect of Painting Series Package on the performance of Junior Secondary School Cultural and Creative Arts in Ogbomoso, Nigeria. Gender influence on the students' performances was also examined. Sample comprised 60 students drawn purposively from two secondary schools.

  16. Self-Esteem of Junior High and High School Students.

    Science.gov (United States)

    Lee, Kimberly E.

    The purpose of this thesis was to investigate the self-esteem of junior high and high school students. The independent variables investigated were quality of family life, birth order, family size, maternal employment, grade level and family structure. The dependent variables were the self-esteem scores from the following sub-scales of the Texas…

  17. Recurrent Respiratory Infections and Psychological Problems in Junior School Children

    Science.gov (United States)

    Kelmanson, Igor A.

    2015-01-01

    Background: Recurrent respiratory infections (RRI) are among most common diseases in school-aged children. Little is known about possible associations between RRI and children psychological well-being. Aim: To study possible associations between RRI in junior school pupils and their emotional/behavioural characteristics. Methods: The RRI group…

  18. [Stop the compulsive PhD trajectory for junior doctors].

    Science.gov (United States)

    Clevers, J C Hans

    2014-01-01

    It has become the rule rather than the exception that junior doctors in training spend 3-4 years on a research project, culminating in a thesis. Without a PhD, clinical career prospects within and outside academia look rather bleak. Here I argue that PhD degrees should be pursued only by the most talented and motivated young clinicians.

  19. Music and Careers for the Junior High Student.

    Science.gov (United States)

    Carlson, Bruce

    The curriculum guide describes an exemplary project designed to provide junior high school students with an opportunity to explore careers related to the world of music. The units present objectives, activities, and resources related to the following occupations: pop music artist, professional musician (union), instrumental and vocal music…

  20. Migration intentions among Portuguese junior doctors: Results from a survey.

    Science.gov (United States)

    Ramos, Pedro; Alves, Hélio

    2017-12-01

    Migration of health personnel during periods of economic crisis represents a challenge for policymakers in origin and destination countries. Portugal is going through a period of economic hardship and much has been speculated about an increase in junior doctors' migration during this period. Using a questionnaire administered to a sample of Portuguese junior doctors who were still in the general residency (1st-year after medical school), we aim at determining the prevalence of migration intentions among Portuguese junior doctors and to identify the most important drivers of career choice for those who are considering emigrating in the near future. In our sample, 55% of Portuguese junior doctors are considering working abroad in the coming 10 years. Several variables were associated with an intention to work abroad: female sex (odds ratio [OR] 0.559; 95% confidence interval [CI] 0.488-0.640), the National Medical Exam score (OR 0.978; 95% CI 0.961-0.996;), having studied abroad (OR 1.756; 95% CI 1.086-2.867) and considering income and research opportunities as key factors for future specialty choice (OR 1.356; 95% CI 1.132-1.626; OR 2.626; 95% CI 1.228-4.172). Our study warns of the shortages the country may face due to doctors' migration and the main factors behind migration intentions in Portugal. Developing physician retention strategies is a priority to appropriately address these factors. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Teaching mathematics creatively in the junior secondary classes ...

    African Journals Online (AJOL)

    This paper tried to emphasize the importance of teaching mathematics with creativity in the Junior Secondary classes (JS1-3) of our education system. It was established that a mathematically creative environment like the mathematics laboratory will enhance the teaching and learning of mathematics in schools. In this study ...

  2. The Influence of Gender on Junior Secondary School Students ...

    African Journals Online (AJOL)

    This paper is on the influence of gender on junior secondary school student's attitude towards mathematics in Ovia North East local government area of Edo state. The descriptive survey design was employed for the study. The population of the study comprised of all the JSS3 students, a total of Three Thousand Six Hundred ...

  3. Sex-Differences in Attitudes towards Mathematics of Junior ...

    African Journals Online (AJOL)

    The study investigated junior secondary school pupils' attitudes towards mathematics. In addition, it investigated gender differences in attitudes towards the subject. The purposive sampling method was used to select nine schools in the Cape Coast Municipality, involving 581 pupils. Questionnaires on attitudes towards ...

  4. The status of basic technology in Cross River State Junior ...

    African Journals Online (AJOL)

    The purpose of the study was to ascertain the status of basic technology in Cross River State junior secondary schools. Descriptive survey design was adopted for the study. The study was guided by three (3) research questions. The population for the study comprised of one hundred and twelve (112) basic technology ...

  5. CAI and Its Application in Rural Junior English Class

    Science.gov (United States)

    He, Xiaojun

    2015-01-01

    Superiority in developing students' listening, speaking, etc. This thesis explores how to provide a better environment for English teaching in rural junior school with the aid of multimedia and find some ways to improve teaching efficiency. In recent years, using multimedia is the direction of reform and mainstream in English teaching. Compared…

  6. Fitness and body composition profiling of elite junior South African ...

    African Journals Online (AJOL)

    Objective. The aim of this study was to describe the body composition, strength and speed characteristics of elite junior South African rugby players. Design. Cross-sectional. Setting. Field study. Subjects. Rugby players (16 and 18 years old, N = 174) selected for the South African Rugby Union National Green Squad.

  7. readability of comprehension passages in junior high school (jhs)

    African Journals Online (AJOL)

    CHARLES

    ... to enhance readability. Key Words: readability formulas, comprehension passages, Junior High School, .... Index has a manual version but in this study the electronic version was used. The ..... probably the majority of the people heard the news by word of mouth. A critical look ..... The Journal of Tourism Studies 9.2: 49-60.

  8. Fitness profile of elite junior South African badminton players | van ...

    African Journals Online (AJOL)

    The purpose of this study was to establish the fitness profile of the elite junior badminton players in South Africa through the measurement and description of their body composition, aerobic power, muscular characteristics, speed, flexibility and agility. Eight elite male and seven elite female badminton players between the ...

  9. IS YOUR DISTRICT READY TO START A JUNIOR COLLEGE.

    Science.gov (United States)

    PATTERSON, DOW

    TO DETERMINE IF A DISTRICT IS READY TO ESTABLISH A JUNIOR COLLEGE, CERTAIN QUESTIONS MUST BE ANSWERED--(1) ARE THERE ENOUGH HIGH SCHOOL GRADUATES TO WARRANT THE PROGRAM WITHOUT UNDUE TAXATION. (2) WILL THE COLLEGE BE ABLE TO OFFER THE USUAL PROGRAMS OF TRANSFER, VOCATIONAL TRAINING, GUIDANCE, AND GENERAL EDUCATION. (3) SHOULD IT BE AN EXTENSION OF…

  10. Selection of Learning Media Mathematics for Junior School Students

    Science.gov (United States)

    Widodo, Sri Adi; Wahyudin

    2018-01-01

    One of the factors that determine the success of mathematics learning is the learning media used. Learning media can help students to create mathematical abstract mathematics that is abstract. In addition to media, meaningful learning is a learning that is adapted to the students' cognitive development. According to Piaget, junior high school…

  11. Vertical Integration at Junior and Intermediate Levels. School Research Newsletter.

    Science.gov (United States)

    Marklund, Inger, Ed.; Hanse, Mona-Britt, Ed.

    1984-01-01

    In recent years, there has been a rapid growth of interest in Sweden in vertically integrated classes in compulsory schools, especially at junior high school and intermediate grade levels. This development is supported in various ways by the curriculum, partly because it puts more emphasis than previous curricula on the occurrence of teaching…

  12. A survey of perceived hindrances to junior secondary school ...

    African Journals Online (AJOL)

    This study investigated situations which Junior Secondary Schools (JSS) teachers perceived as hindrances to their teaching functions. A 30-item questionnaire with a 5-point scale was used to collect data from 116 science teachers who taught in private and public schools. The schools were based in rural and urban ...

  13. development and validation of an instrument for assessing junior ...

    African Journals Online (AJOL)

    PROF. BARTH EKWEME

    school Mathematics classroom environment as it affects teaching and learning of Mathematics in Enugu. State. ... plays a significant role in computer technology. ... classroom. The main purpose of this study was to develop and validate an instrument for assessing junior secondary school Mathematics classroom learning ...

  14. Analysis of Daily Life Time in Women's Junior College Students

    OpenAIRE

    樫村, 修生

    1992-01-01

    The purpose of this investigation was understand the correlationship between the energy expenditure of living activity and body structure or physical fitness in the students of a women's junior college. The resulut were as follows; It was shown that the physical activites in the daily life was necessary for prevention of obesity in the students.

  15. Head Impact Exposure in Junior and Adult Australian Football Players

    Directory of Open Access Journals (Sweden)

    Mark Hecimovich

    2018-01-01

    Full Text Available This study measured and compared the frequency, magnitude, and distribution of head impacts sustained by junior and adult Australian football players, respectively, and between player positions over a season of games. Twelve junior and twelve adult players were tracked using a skin-mounted impact sensor. Head impact exposure, including frequency, magnitude, and location of impacts, was quantified using previously established methods. Over the collection period, there were no significant differences in the impact frequency between junior and adult players. However, there was a significant increase in the frequency of head impacts for midfielders in both grades once we accounted for player position. A comparable amount of head impacts in both junior and adult players has implications for Australian football regarding player safety and medical coverage as younger players sustained similar impact levels as adult players. The other implication of a higher impact profile within midfielders is that, by targeting education and prevention strategies, a decrease in the incidence of sports-related concussion may result.

  16. Literacy in Community Colleges. Junior College Resource Review.

    Science.gov (United States)

    Yarrington, Roger; And Others

    This series of Junior College Resource Reviews focuses on the community college's role in literacy development. After Roger Yarrington's overview of the topic, Robert McCabe and Susan Skidmore consider "The Literacy Crisis and American Education." In light of the changing nature of work and the severe decline in the communication skills of youth,…

  17. Sex-Differences in Attitudes towards Mathematics of Junior ...

    African Journals Online (AJOL)

    cce

    The study investigated junior secondary school pupils' attitudes towards mathematics. ... They attributed this to their low interest and confidence in learning ... aspirations performed better in mathematics and science than those who did not .... The questionnaire items were hand delivered to respondents on the days that ...

  18. Sex-Differences in Attitudes towards Mathematics of Junior ...

    African Journals Online (AJOL)

    cce

    Abstract. The study investigated junior secondary school pupils' attitudes towards mathematics. In addition, it investigated gender differences in attitudes towards the subject. The purposive sampling method was used to select nine schools in the Cape Coast. Municipality, involving 581 pupils. Questionnaires on attitudes ...

  19. A Comparison of Isometric Midthigh-Pull Strength, Vertical Jump, Sprint Speed, and Change-of-Direction Speed in Academy Netball Players.

    Science.gov (United States)

    Thomas, Christopher; Comfort, Paul; Jones, Paul A; Dos'Santos, Thomas

    2017-08-01

    To investigate the relationships between maximal isometric strength, vertical jump (VJ), sprint speed, and change-of-direction speed (CoDS) in academy netball players and determine whether players who have high performance in isometric strength testing would demonstrate superior performance in VJ, sprint speed, and CoDS measures. Twenty-six young female netball players (age 16.1 ± 1.2 y, height 173.9 ± 5.7 cm, body mass 66.0 ± 7.2 kg) from a regional netball academy performed isometric midthigh pull (IMTP), squat jumps (SJs), countermovement jumps (CMJs), 10-m sprints, and CoDS (505). IMTP measures displayed moderate to strong correlations with sprint and CoDS performance (r = -.41 to -.66). The VJs, which included SJs and CMJs, demonstrated strong correlations with 10-m sprint times (r = -.60 to -.65; P strength to enhance VJ, sprint, and CoDS performance in youth netball players, with stronger athletes demonstrating superior VJ, sprint, and CoDS performances.

  20. Breaking the speed limit--comparative sprinting performance of brook trout (Salvelinus fontinalis) and brown trout (Salmo trutta)

    Science.gov (United States)

    Castro-Santos, Theodore; Sanz-Ronda, Francisco Javier; Ruiz-Legazpi, Jorge

    2013-01-01

    Sprinting behavior of free-ranging fish has long been thought to exceed that of captive fish. Here we present data from wild-caught brook trout (Salvelinus fontinalis) and brown trout (Salmo trutta), volitionally entering and sprinting against high-velocity flows in an open-channel flume. Performance of the two species was nearly identical, with the species attaining absolute speeds > 25 body lengths·s−1. These speeds far exceed previously published observations for any salmonid species and contribute to the mounting evidence that commonly accepted estimates of swimming performance are low. Brook trout demonstrated two distinct modes in the relationship between swim speed and fatigue time, similar to the shift from prolonged to sprint mode described by other authors, but in this case occurring at speeds > 19 body lengths·s−1. This is the first demonstration of multiple modes of sprint swimming at such high swim speeds. Neither species optimized for distance maximization, however, indicating that physiological limits alone are poor predictors of swimming performance. By combining distributions of volitional swim speeds with endurance, we were able to account for >80% of the variation in distance traversed by both species.

  1. Sprint Running Performance and Technique Changes in Athletes During Periodized Training: An Elite Training Group Case Study.

    Science.gov (United States)

    Bezodis, Ian N; Kerwin, David G; Cooper, Stephen-Mark; Salo, Aki I T

    2017-11-15

    To understand how training periodization influences sprint performance and key step characteristics over an extended training period in an elite sprint training group. Four sprinters were studied during five months of training. Step velocities, step lengths and step frequencies were measured from video of the maximum velocity phase of training sprints. Bootstrapped mean values were calculated for each athlete for each session and 139 within-athlete, between-session comparisons were made with a repeated measures ANOVA. As training progressed, a link in the changes in velocity and step frequency was maintained. There were 71 between-session comparisons with a change in step velocity yielding at least a large effect size (>1.2), of which 73% had a correspondingly large change in step frequency in the same direction. Within-athlete mean session step length remained relatively constant throughout. Reductions in step velocity and frequency occurred during training phases of high volume lifting and running, with subsequent increases in step velocity and frequency happening during phases of low volume lifting and high intensity sprint work. The importance of step frequency over step length to the changes in performance within a training year was clearly evident for the sprinters studied. Understanding the magnitudes and timings of these changes in relation to the training program is important for coaches and athletes. The underpinning neuro-muscular mechanisms require further investigation, but are likely explained by an increase in force producing capability followed by an increase in the ability to produce that force rapidly.

  2. Mental skills comparison between elite sprint and endurance track and field runners according to their genetic polymorphism: a pilot study.

    Science.gov (United States)

    Znazen, Hela; Slimani, Maamer; Miarka, Bianca; Butovskaya, Marina; Siala, Hajer; Messaoud, Taieb; Chamari, Karim; Souissi, Nizar

    2017-09-01

    Achieving excellence in track and field athletes requires specific mental skills. The aim of the present study was to compare the mental skills between elite sprint and endurance athletes. Forty elite athletes (age 20.55±2.22 years, body mass 74.8±7.9 kg, height 1.70±0.1 m) participated in the present study. The athletes were classified into two groups according to their genetic polymorphism to physical activity: Endurance group (allele I, N.=20) and power group (allele D, N.=20). The mental skills were assessed by means of Ottawa Mental Skill Assessment Tool-3 inventory (OMSAT-3: based in foundation mental skills, psychosomatic skills, and cognitive skills subscales) before the competition period. Furthermore, genetic data were also collected. Sprint and endurance runners were participating in Tunisian National championship. The results showed a significant difference between elite sprint and endurance runners in the foundation mental and psychosomatic skills subscales (all, Pstudy revealed that goal setting, commitment, stress reactions, fear control, imagery, competition planning and mental practice were significantly higher among the elite sprint runners compared to the endurance runners (all, Pstudy could confirm the widely acclaimed research assumption that mental skills, such as goal setting, commitment and mental practice, are the predictor variables of power performances, while endurance performances are associated with different mental skills components. Finally, the results may inform applied practitioners regarding the differences in mental skill demands between power and endurance athletes and the genetic predisposition of practitioners.

  3. Application of the Copenhagen Soccer Test in high-level women players - locomotor activities, physiological response and sprint performance.

    Science.gov (United States)

    Bendiksen, Mads; Pettersen, Svein Arne; Ingebrigtsen, Jørgen; Randers, Morten B; Brito, João; Mohr, Magni; Bangsbo, Jens; Krustrup, Peter

    2013-12-01

    We evaluated the physiological response, sprint performance and technical ability in various phases of the Copenhagen Soccer Test for Women (CSTw) and investigated whether the locomotor activities of the CSTw were comparable to competitive match-play (CM). Physiological measurements and physical/technical assessments were performed during CSTw for eleven Norwegian high-level women soccer players. The activity pattern during CSTw and CM was monitored using the ZXY tracking system. No differences were observed between CSTw and CM with regards to total distance covered (10093±94 and 9674±191m), high intensity running (1278±67 and 1193±115m) or sprinting (422±55 and 372±46m) (p>.05). During CSTw, average HR was 85±2%HRmax with 35±2% playing time >90%HRmax. Blood lactate increased (ptest. Blood glucose was 5.4±0.3mM at rest and remained unaltered during CSTw. Sprint performance (2×20m) decreased (plocomotor activities during CSTw were comparable to that of high-level competitive match-play. The physiological demands of the CSTw were high, with no changes in heart rate, blood lactate or technical performance during the test, but a lowered sprint performance towards the end of the test. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Feasibility and reliability of measuring strength, sprint power, and aerobic capacity in athletes and non-athletes with cerebral palsy

    NARCIS (Netherlands)

    De Groot, Sonja; Janssen, Thomas W. J.; Evers, Marijn; Van der Luijt, Pieter; Nienhuys, Kirsten N. G.; Dallmeijer, Annet J.

    Aim The aim of this study was to analyse the feasibility and reliability of the tests used to determine muscle strength, sprint power, and aerobic capacity in athletes and non-athletes with cerebral palsy (CP). Methods Twenty individuals with spastic CP (four females, 16 males; age range 1849y;

  5. Muscle morphology of the vastus lateralis is strongly related to ergometer performance, sprint capacity and endurance capacity in Olympic rowers

    NARCIS (Netherlands)

    van der Zwaard, Stephan; Weide, Guido; Levels, Koen; Eikelboom, Michelle R.I.; Noordhof, Dionne A.; Hofmijster, Mathijs J.; van der Laarse, Willem J.; de Koning, Jos J.; de Ruiter, Cornelis J.; Jaspers, Richard T.

    2018-01-01

    Rowers need to combine high sprint and endurance capacities. Muscle morphology largely explains muscle power generating capacity, however, little is known on how muscle morphology relates to rowing performance measures. The aim was to determine how muscle morphology of the vastus lateralis relates

  6. Validity of the Pediatric Running-Based Anaerobic Sprint Test to Determine Anaerobic Performance in Healthy Children

    NARCIS (Netherlands)

    Bongers, Bart C.; Werkman, Maarten S.; Blokland, Donna; Eijsermans, Maria J. C.; van der Torre, Patrick; Bartels, Bart; Verschuren, Olaf; Takken, Tim

    Purpose: To determine criterion validity of the pediatric running-based anaerobic sprint test (RAST) as a nonsophisticated field test for evaluating anaerobic performance in healthy children and adolescents. Methods: Data from 65. healthy children (28 boys and 37 girls between 6 and 18 years of age,

  7. Feasibility and reliability of measuring strength, sprint power, and aerobic capacity in athletes and non-athletes with cerebral palsy

    NARCIS (Netherlands)

    de Groot, S.; Janssen, T.W.J.; Evers, M.; Van der Luijt, P.; Nienhuys, K.N.G.; Dallmeijer, A.J.

    2012-01-01

    Aim The aim of this study was to analyse the feasibility and reliability of the tests used to determine muscle strength, sprint power, and aerobic capacity in athletes and non-athletes with cerebral palsy (CP). Methods Twenty individuals with spastic CP (four females, 16 males; age range 18-49y;

  8. Acute and Post-Exercise Physiological Responses to High-Intensity Interval Training in Endurance and Sprint Athletes

    Science.gov (United States)

    Cipryan, Lukas; Tschakert, Gerhard; Hofmann, Peter

    2017-01-01

    The purpose of the presented study was to compare acute and post-exercise differences in cardiorespiratory, metabolic, cardiac autonomic, inflammatory and muscle damage responses to high-intensity interval exercise (HIIT) between endurance and sprint athletes. The study group consisted of sixteen highly-trained males (age 22.1 ± 2.5 years) participating in endurance (n = 8) or sprint (n = 8) sporting events. All the participants underwent three exercise sessions: short HIIT (work interval duration 30s), long HIIT (3min) and constant load exercise (CE). The exercise interventions were matched for mean power, total time and in case of HIIT interventions also for work-to-relief ratio. The acute cardiorespiratory (HR, V̇O2, RER) and metabolic (lactate) variables as well as the post-exercise changes (up to 3 h) in the heart rate variability, inflammation (interleukin-6, leucocytes) and muscle damage (creatine kinase, myoglobin) were monitored. Endurance athletes performed exercise interventions with moderately (CE) or largely (both HIIT modes) higher mean V̇O2. These differences were trivial/small when V̇O2 was expressed as a percentage of V̇O2max. Moderately to largely lower RER and lactate values were found in endurance athletes. Markers of cardiac autonomic regulation, inflammation and muscle damage did not reveal any considerable differences between endurance and sprint athletes. In conclusions, endurance athletes were able to perform both HIIT formats with increased reliance on aerobic metabolic pathways although exercise intensity was identical in relative terms for all the participants. However, other markers of the acute and early post-exercise physiological response to these HIIT interventions indicated similarities between endurance and sprint athletes. Key points The manner in which each training background (endurance vs. sprint) influences the response to HIIT is not well known. Despite the identical exercise intensity in relative terms, endurance

  9. Higher Drop in Speed during a Repeated Sprint Test in Soccer Players Reporting Former Hamstring Strain Injury

    Science.gov (United States)

    Røksund, Ola D.; Kristoffersen, Morten; Bogen, Bård E.; Wisnes, Alexander; Engeseth, Merete S.; Nilsen, Ann-Kristin; Iversen, Vegard V.; Mæland, Silje; Gundersen, Hilde

    2017-01-01

    Aim: Hamstring strain injury is common in soccer. The aim of this study was to evaluate the physical capacity of players who have and have not suffered from hamstring strain injury in a sample of semi-professional and professional Norwegian soccer players in order to evaluate characteristics and to identify possible indications of insufficient rehabilitation. Method: Seventy-five semi-professional and professional soccer players (19 ± 3 years) playing at the second and third level in the Norwegian league participated in the study. All players answered a questionnaire, including one question about hamstring strain injury (yes/no) during the previous 2 years. They also performed a 40 m maximal sprint test, a repeated sprint test (8 × 20 m), a countermovement jump, a maximal oxygen consumption (VO2max) test, strength tests and flexibility tests. Independent sample t-tests were used to evaluate differences in the physical capacity of the players who had suffered from hamstring strain injury and those who had not. Mixed between-within subject's analyses of variance was used to compare changes in speed during the repeated sprint test between groups. Results: Players who reported hamstring strain injury during the previous two years (16%) had a significantly higher drop in speed (0.07 vs. 0.02 s, p = 0.007) during the repeated sprint test, compared to players reporting no previous hamstring strain injury. In addition, there was a significant interaction (groups × time) (F = 3.22, p = 0.002), showing that speed in the two groups changed differently during the repeated sprint test. There were no significant differences in relations to age, weight, height, body fat, linear speed, countermovement jump height, leg strength, VO2max, or hamstring flexibility between the groups. Conclusion: Soccer players who reported hamstring strain injury during the previous 2 years showed significant higher drop in speed during the repeated sprint test compared to players with no hamstring

  10. High-intensity sprint fatigue does not alter constant-submaximal velocity running mechanics and spring-mass behavior.

    Science.gov (United States)

    Morin, Jean-Benoit; Tomazin, Katja; Samozino, Pierre; Edouard, Pascal; Millet, Guillaume Y

    2012-04-01

    We investigated the changes in constant velocity spring-mass behavior after high intensity sprint fatigue in order to better interpret the results recently reported after ultra-long distance (ULD) exercises. Our hypothesis was that after repeated sprints (RS), subjects may likely experience losses of force such as after ULD, but the necessity to modify their running pattern to attenuate the overall impact at each step (such as after ULD) may not be present. Eleven male subjects performed four sets of five 6-s sprints with 24-s recovery between sprints and 3 min between sets, on a sprint treadmill and on a bicycle ergometer. For each session, their running mechanics and spring-mass characteristics were measured at 10 and 20 km h(-1) on an instrumented treadmill before and after RS. Two-way (period and velocity) ANOVAs showed that high-intensity fatigue did not induce any change in the constant velocity running pattern at low or high velocity, after both running and cycling RS, despite significant decreases (P < 0.001) in maximal power (-27.1 ± 8.2% after running RS and -15.4 ± 11.5 % after cycling RS) and knee extensors maximal voluntary force (-18.8 ± 6.7 % after running RS and -15.0 ± 7.6 % after cycling RS). These results bring indirect support to the hypothesis put forward in recent ULD studies that the changes in running mechanics observed after ULD are likely not related to the decrease in strength capabilities, but rather to the necessity for subjects to adopt a protective running pattern.

  11. Acute Ingestion of Caffeinated Chewing Gum Improves Repeated Sprint Performance of Team Sport Athletes With Low Habitual Caffeine Consumption.

    Science.gov (United States)

    Evans, Mark; Tierney, Peter; Gray, Nicola; Hawe, Greg; Macken, Maria; Egan, Brendan

    2018-04-23

    The effects of acute ingestion of caffeine on short-duration high-intensity performance are equivocal, while studies of novel modes of delivery and the efficacy of low doses of caffeine are warranted. The aims of the present study were to investigate the effect of acute ingestion of caffeinated chewing gum on repeated sprint performance (RSP) in team sport athletes, and whether habitual caffeine consumption alters the ergogenic effect, if any, on RSP. A total of 18 male team sport athletes undertook four RSP trials using a 40-m maximum shuttle run test, which incorporates 10 × 40-m sprints with 30 s between the start of each sprint. Each participant completed two familiarization sessions, followed by caffeine (CAF; caffeinated chewing gum; 200 mg caffeine) and placebo (PLA; noncaffeinated chewing gum) trials in a randomized, double-blind manner. RSP, assessed by sprint performance decrement (%), did not differ (p = .209; effect size = 0.16; N = 18) between CAF (5.00 ± 2.84%) and PLA (5.43 ± 2.68%). Secondary analysis revealed that low habitual caffeine consumers (130 mg/day, n = 6; 3.98 ± 2.57% vs. 3.80 ± 1.79%, respectively; p = .684; effect size = 0.08). The data suggest that a low dose of caffeine in the form of caffeinated chewing gum attenuates the sprint performance decrement during RSP by team sport athletes with low, but not moderate-to-high, habitual consumption of caffeine.

  12. Comparison of three types of full‐body compression garments on throwing and repeat‐sprint performance in cricket players

    Science.gov (United States)

    Duffield, Rob; Portus, Marc

    2007-01-01

    Objective To compare the effects of three types of full‐body compression garments (Skins, Adidas and Under Armour) on repeat‐sprint and throwing performance in cricket players. Methods Following familiarisation, 10 male cricket players performed four randomised exercise sessions (3 garments and a control). Each session involved a 30 min repeat‐sprint exercise protocol comprising 20 m sprints every minute, separated by submaximal exercise. Throwing tests included a pre‐exercise and a postexercise maximal distance test and accuracy throwing tests. During each session, measures of heart rate, skin temperature, change in body mass, rate of perceived exertion and perceived muscle soreness were recorded. Capillary blood samples were analysed before and after exercise for lactate, pH, O2 saturation and O2 partial pressure, and 24 h after exercise for creatine kinase (CK). Ratings of perceived muscle soreness were also obtained 24 h after exercise. Results No significant differences (p>0.05) were evident in repeat‐sprint performance (10 m, 20 m time or total submaximal distance covered) or throwing performance (maximum distance or accuracy). No significant differences (p>0.05) were observed in heart rate, body mass change or blood measures during exercise. Significant differences (p0.05). Conclusions No benefit was noted when wearing compression garments for repeat‐sprint or throwing performance; however, the use of the garments as a recovery tool, when worn after exercise, may be beneficial to reduce postexercise trauma and perceived muscle soreness. PMID:17341589

  13. Effect of formoterol, a long-acting β2-adrenergic agonist, on muscle strength and power output, metabolism and fatigue during maximal sprinting in men

    DEFF Research Database (Denmark)

    Kalsen, Anders; Hostrup, Morten; Backer, Vibeke

    2016-01-01

    The aim was to investigate the effect of the long-acting β2-adrenergic agonist formoterol on muscle strength and power output, muscle metabolism and phosphorylation of CaMKII Thr(287) and FXYD1 during maximal sprinting. In a double-blind crossover study, thirteen males (VO2max: 45.0±0.2 (mean±SE) m......L min(-1) kg(-1)) performed a 30-s cycle ergometer sprint after inhalation of either 54 µg formoterol (FOR) or placebo (PLA). Before and after the sprint, muscle biopsies were collected from vastus lateralis and maximal voluntary contraction (MVC) and contractile properties of quadriceps were measured...

  14. Acute responses of circulating microRNAs to low-volume sprint interval cycling

    Directory of Open Access Journals (Sweden)

    Shu Fang eCui

    2015-10-01

    Full Text Available Low-volume high-intensity interval training is an efficient and practical method of inducing physiological responses in various tissues to develop physical fitness and may also change the expression of circulating microRNAs (miRNAs. The purpose of the present study was to examine whether miRNAs for muscle, heart, somatic tissue and metabolism were affected by 30-s intervals of intensive sprint cycling. We also examined the relationship of these miRNAs to conventional biochemical and performance indices. Eighteen healthy young males performed sprint interval cycling. Circulating miRNAs in plasma were detected using TaqMan-based quantitative PCR and normalized to Let-7d/g/i. In addition, we determined the levels of insulin-like growth factor-I, testosterone and cortisol, and anaerobic capacity. Compared to plasma levels before exercise muscle-specific miR-1 (0.12 ± 0.02 vs. 0.09 ± 0.02, miR-133a (0.46 ± 0.10 vs. 0.31 ± 0.06 and miR-133b (0.19 ± 0.02 vs. 0.10 ± 0.01 decreased (all P < 0.05, while miR-206 and miR-499 remained unchanged. The levels of metabolism related miR-122 (0.62 ± 0.07 vs. 0.34 ± 0.03 and somatic tissues related miR-16 (1.74 ± 0.27 vs. 0.94 ± 0.12 also decreased (both P < 0.05. The post-exercise IGF-1 and cortisol concentrations were significantly increased, while testosterone concentrations did not. Plasma levels of miR-133b correlated to peak power (r = 0.712, P = 0.001 and miR-122 correlated to peak power ratio (r = 0.665, P = 0.003. In conclusion sprint exercise provokes genetic changes for RNA related to specific muscle or metabolism related miRNAs suggesting that miR-133b and miR-122 may be potential useful biomarkers for actual physiological strain or anaerobic capacity. Together, our findings on the circulating miRNAs may provide new insight into the physiological responses that are being performed during exercise and delineate mechanisms by which exercise confers distinct phenotypes and improves performance.

  15. FAMILIARISATION AND RELIABILITY OF SPRINT TEST INDICES DURING LABORATORY AND FIELD ASSESSMENT

    Directory of Open Access Journals (Sweden)

    Andrew Galbraith

    2009-12-01

    Full Text Available The aim of the study was to assess the reliability of sprint performance in both field and laboratory conditions. Twenty-one male (mean ± s: 19 ± 1 years, 1.79 ± 0.07 m, 77.6 ± 7.1 kg and seventeen female team sport players (mean ± s: 21 ± 4 years, 1.68 ± 0. 07 m, 62.7 ± 4.7 kg performed a maximal 20-metre sprint running test on eight separate occasions. Four trials were conducted on a non-motorised treadmill in the laboratory; the other four were conducted outdoors on a hard-court training surface with time recorded by single-beam photocells. Trials were conducted in random order with no familiarisation prior to testing. There was a significant difference between times recorded during outdoor field trials (OFT and indoor laboratory trials (ILT using a non-motorised treadmill (3.47 ± 0.53 vs. 6.06 ±1.17s; p < 0.001. The coefficient of variation (CV for time was 2.55-4.22% for OFT and 5.1-7.2% for ILT. During ILT peak force (420.9 ± 87.7N, mean force (147.2 ± 24.7N, peak power (1376.8 ± 451.9W and mean power (514.8 ± 164.4W, and were measured. The CV for all ILT variables was highest during trial 1-2 comparison. The CV (95% confidence interval for the trial 3-4 comparison yielded: 9.4% (7.7-12. 1%, 7.9% (6.4-10.2%, 10.1% (8.2-13.1% and 6.2% (5.1-8.0% for PF, MF, PP and MP and respectively. The results indicate that reliable data can be derived for single maximal sprint measures, using fixed distance protocols. However, significant differences in time/speed over 20-m exist between field and laboratory conditions. This is primarily due to the frictional resistance in the non- motorised treadmill. Measures of force and power during ILT require at least 3 familiarisations to reduce variability in test scores

  16. Physiological and performance changes from the addition of a sprint interval program to wrestling training.

    Science.gov (United States)

    Farzad, Babak; Gharakhanlou, Reza; Agha-Alinejad, Hamid; Curby, David G; Bayati, Mahdi; Bahraminejad, Morteza; Mäestu, Jarek

    2011-09-01

    Increasing the level of physical fitness for competition is the primary goal of any conditioning program for wrestlers. Wrestlers often need to peak for competitions several times over an annual training cycle. Additionally, the scheduling of these competitions does not always match an ideal periodization plan and may require a modified training program to achieve a high level of competitive fitness in a short-time frame. The purpose of this study was to examine the effects of 4 weeks of sprint-interval training (SIT) program, on selected aerobic and anaerobic performance indices, and hormonal and hematological adaptations, when added to the traditional Iranian training of wrestlers in their preseason phase. Fifteen trained wrestlers were assigned to either an experimental (EXP) or a control (CON) group. Both groups followed a traditional preparation phase consisting of learning and drilling technique, live wrestling and weight training for 4 weeks. In addition, the EXP group performed a running-based SIT protocol. The SIT consisted of 6 35-m sprints at maximum effort with a 10-second recovery between each sprint. The SIT protocol was performed in 2 sessions per week, for the 4 weeks of the study. Before and after the 4-week training program, pre and posttesting was performed on each subject on the following: a graded exercise test (GXT) to determine VO(2)max, the velocity associated with V(2)max (νVO(2)max), maximal ventilation, and peak oxygen pulse; a time to exhaustion test (T(max)) at their νVO(2)max; and 4 successive Wingate tests with a 4-minute recovery between each trial for the determination of peak and mean power output (PPO, MPO). Resting blood samples were also collected at the beginning of each pre and posttesting period, before and after the 4-week training program. The EXP group showed significant improvements in VO(2)max (+5.4%), peak oxygen pulse (+7.7%) and T(max) (+32.2%) compared with pretesting. The EXP group produced significant increases

  17. The Progression of Male 100 m Sprinting with a Lower-Limb Amputation 1976–2012

    Directory of Open Access Journals (Sweden)

    Bryce Dyer

    2015-02-01

    Full Text Available Sprinting with a lower-limb amputation over 100 m has taken place in the Paralympic Games for over three decades. The aim of this paper is to statistically evaluate the performances and participation levels of such athletes during this period. The level of performance improvement over a 36-year period was proposed to be significantly greater than the able-bodied equivalent. Coupled with this, a major spike in amputee running performance improvement was shown to occur from 1984–1988. This supports previously recorded accounts of a major technological change being made at this time. Finally, whilst the average performance of the medallists has increased consistently over the 36-year history, the overall participation in the event fell significantly after 1988 and did not recover until 2012.

  18. Open Science & Open Data Global Sprint 2016 | 2–3 June 2016

    CERN Multimedia

    Achintya Rao

    2016-01-01

    Join us as we learn to collaboratively build projects transforming science on the web! Thursday 2 June 2016 8.00 a.m. – Friday 3 June 20.00 p.m. CERN (3179-R-E06) This two-day sprint event brings together researchers, coders, librarians and the public from around the globe to hack on open science and open data projects in their communities. This year, we have four tracks you can contribute to: tools, citizen science, curriculum and open data. CERN is hosting three projects: Everware Open Cosmics CrowdAI   You can also participate in any of the other mozsprint projects for 2016. For more information, please visit: https://indico.cern.ch/event/535760/

  19. Metabolic Responses and Pacing Strategies during Successive Sprint Skiing Time Trials

    DEFF Research Database (Denmark)

    Andersson, Erik; Holmberg, Hans-Christer; Ørtenblad, Niels

    2016-01-01

    PURPOSE: To examine the metabolic responses and pacing strategies during the performance of successive sprint time trials (STTs) in cross-country skiing. METHODS: Ten well-trained male cross-country skiers performed four self-paced 1300-m STTs on a treadmill, each separated by 45 min of recovery...... to estimate the anaerobic energy supply. RESULTS: The individual trial-to-trial variability in STT performance time was 1.3%, where variations in O2 deficit and V˙O2 explained 69% (P 0.05) of the variation in performance. The first and last STTs were equally fast (228 ± 10 s), and ~ 1...... on the first than second course half. In addition, metabolic rates were substantially higher (~_30%) for uphill than for flat skiing, indicating that pacing was regulated to the terrain. CONCLUSIONS: The fastest STTs were characterized primarily by a greater anaerobic energy production, which also explained 69...

  20. A Combination of Amino Acids and Caffeine Enhances Sprint Running Capacity in a Hot, Hypoxic Environment.

    Science.gov (United States)

    Eaton, Tom R; Potter, Aaron; Billaut, François; Panchuk, Derek; Pyne, David B; Gore, Christopher J; Chen, Ting-Ting; McQuade, Leon; Stepto, Nigel K

    2016-02-01

    Heat and hypoxia exacerbate central nervous system (CNS) fatigue. We therefore investigated whether essential amino acid (EAA) and caffeine ingestion attenuates CNS fatigue in a simulated team sport-specific running protocol in a hot, hypoxic environment. Subelite male team sport athletes (n = 8) performed a repeat sprint running protocol on a nonmotorized treadmill in an extreme environment on 4 separate occasions. Participants ingested one of four supplements: a double placebo, 3 mg.kg-1 body mass of caffeine + placebo, 2 x 7 g EAA (Musashi Create)+placebo, or caffeine + EAA before each exercise session using a randomized, double-blind crossover design. Electromyography (EMG) activity and quadriceps evoked responses to magnetic stimulation were assessed from the dominant leg at preexercise, halftime, and postexercise. Central activation ratio (CAR) was used to quantify completeness of quadriceps activation. Oxygenation of the prefrontal cortex was measured via near-infrared spectroscopy. Mean sprint work was higher (M = 174 J, 95% CI [23, 324], p beneficial) in the caffeine + EAA condition versus EAAs alone. The decline in EMG activity was less (M = 13%, 95% CI [0, 26]; p beneficial) in caffeine + EAA versus EAA alone. Similarly, the pre- to postexercise decrement in CAR was significantly less (M = -2.7%, 95% CI [0.4, 5.4]; p beneficial) when caffeine + EAA were ingested compared with placebo. Cerebral oxygenation was lower (M = -5.6%, 95% CI [1.0, 10.1]; p beneficial) in the caffeine + EAA condition compared with LNAA alone. Co-ingestion of caffeine and EAA appears to maintain muscle activation and central drive, with a small improvement in running performance.

  1. SPRINT-INTERVAL TRAINING INDUCES HEAT SHOCK PROTEIN 72 IN RAT SKELETAL MUSCLES

    Directory of Open Access Journals (Sweden)

    Yuji Ogura

    2006-06-01

    Full Text Available Previous studies have demonstrated that endurance exercise training increases the level of heat shock proteins (HSPs in skeletal muscles. However, little attention has been drawn to the effects of high intensity-short duration exercise, or sprint- interval training (SIT on HSP72 level in rat skeletal muscles. This study performed to test the hypothesis that the SIT would induce the HSP72 in fast and slow skeletal muscles of rats. Young male Wistar rats (8 weeks old were randomly assigned to a control (CON or a SIT group (n = 8/group. Animals in the SIT group were trained (1 min/sprint, 6~10 sets/day and 5~6 days/week on a treadmill for 9 weeks. After the training period, HSP72 levels in the plantaris (fast and soleus (slow muscles were analyzed by Western blotting method. Enzyme activities (hexokinase, phosphofructokinase and citrate synthase and histochemical properties (muscle fiber type compositions and cross sectional area in both muscles were also determined. The SIT resulted in significantly (p < 0.05 higher levels of HSP72 in both the plantaris and soleus muscles compared to the CON group, with the plantaris producing a greater HSP72 increase than the soleus (plantaris; 550 ± 116%, soleus; 26 ± 8%, p < 0.05. Further, there were bioenergetic improvements, fast-to-slow shift of muscle fiber composition and hypertrophy in the type IIA fiber only in the plantaris muscle. These findings indicate that the SIT program increases HSP72 level of the rat hindlimb muscles, and the SIT-induced accumulation of HSP72 differs between fast and slow muscles

  2. Sex Comparison of Knee Extensor Size, Strength and Fatigue Adaptation to Sprint Interval Training.

    Science.gov (United States)

    Bagley, Liam; Al-Shanti, Nasser; Bradburn, Steven; Baig, Osamah; Slevin, Mark; McPhee, Jamie S

    2018-03-12

    Regular sprint interval training (SIT) improves whole-body aerobic capacity and muscle oxidative potential, but very little is known about knee extensor anabolic or fatigue resistance adaptations, or whether effects are similar for males and females. The purpose of this study was to compare sex-related differences in knee extensor size, torque-velocity relationship and fatigability adaptations to 12 weeks SIT. Sixteen males and fifteen females (mean (SEM) age: 41 (±2.5) yrs) completed measurements of total body composition assessed by DXA, quadriceps muscle cross-sectional area (CSAQ) assessed by MRI, the knee extensor torque-velocity relationship (covering 0 - 240°·sec) and fatigue resistance, which was measured as the decline in torque from the first to the last of 60 repeated concentric knee extensions performed at 180°·sec. SIT consisted of 4 x 20 second sprints on a cycle ergometer set at an initial power output of 175% of power at VO2max, three times per week for 12 weeks. CSAQ increased by 5% (p=0.023) and fatigue resistance improved 4.8% (p=0.048), with no sex differences in these adaptations (sex comparisons: p=0.140 and p=0.282, respectively). Knee extensor isometric and concentric torque was unaffected by SIT in both males and females (p>0.05 for all velocities). 12 weeks SIT, totalling 4 minutes very intense cycling per week, significantly increased fatigue resistance and CSAQ similarly in males and females, but did not significantly increase torque in males or females. These results suggest that SIT is a time-effective training modality for males and females to increase leg muscle size and fatigue resistance.

  3. Cold water immersion recovery following intermittent-sprint exercise in the heat.

    Science.gov (United States)

    Pointon, Monique; Duffield, Rob; Cannon, Jack; Marino, Frank E

    2012-07-01

    This study examined the effects of cold water immersion (CWI) on recovery of neuromuscular function following simulated team-sport exercise in the heat. Ten male team-sport athletes performed two sessions of a 2 × 30-min intermittent-sprint exercise (ISE) in 32°C and 52% humidity, followed by a 20-min CWI intervention or passive recovery (CONT) in a randomized, crossover design. The ISE involved a 15-m sprint every minute separated by bouts of hard running, jogging and walking. Voluntary and evoked neuromuscular function, ratings of perceived muscle soreness (MS) and blood markers for muscle damage were measured pre- and post-exercise, immediately post-recovery, 2-h and 24-h post-recovery. Measures of core temperature (Tcore), heart rate (HR), capillary blood and perceptions of exertion, thermal strain and thirst were also recorded at the aforementioned time points. Post-exercise maximal voluntary contraction (MVC) and activation (VA) were reduced in both conditions and remained below pre-exercise values for the 24-h recovery (P recovery period (P recovery rate of reduction in Tcore, HR and MS was enhanced with CWI whilst increasing MVC and VA (P recovery MVC and activation were significantly higher in CONT compared to CWI (P = 0.05). Following exercise in the heat, CWI accelerated the reduction in thermal and cardiovascular load, and improved MVC alongside increased central activation immediately and 2-h post-recovery. However, despite improved acute recovery CWI resulted in an attenuated MVC 24-h post-recovery.

  4. Determinant Factors of the Squat Jump in Sprinting and Jumping Athletes

    Directory of Open Access Journals (Sweden)

    González-Badillo Juan José

    2017-08-01

    Full Text Available The aim of this study was to assess the relationship between strength variables and maximum velocity (Vmax in the squat jump (SJ in sprinting and jumping athletes. Thirty-two sprinting and jumping athletes of national level (25.4 ± 4.5 years; 79.4 ± 6.9 kg and 180.4 ± 6.0 cm participated in the study. Vmax in the SJ showed significant relationships with peak force 1 (PF1 (r = 0.82, p ≤ 0.001, peak force 2 (PF2 (r = 0.68, p ≤ 0.001, PF2 by controlling for PF1 (r = 0.30, non-significant, the maximum rate of force development at peak force 1 (RFDmax1 (r = 0.62, p ≤ 0.001, mean RFD 1 (RFDmean1 (r = 0.48, p ≤ 0.01, mean RFD 2 (RFDmean2 (r = 0.70, p ≤ 0.001, force at RFDmax1 (r = 0.36, p ≤ 0.05, force at RFDmax2 (r = 0.83, p ≤ 0.001 and force at RFDmax2 by controlling for PF1 (r = 0.40, p ≤ 0.05. However, Vmax in the SJ was associated negatively with the ratio PF2/PF1 (r = -0.54, p ≤ 0.01, time at peak force 2 (Tp2 (r = -0.64, p ≤ 0.001 and maximum rate of force development at peak force 2 (RFDmax2 (r = -0.71, p ≤ 0.001. These findings indicate that the peak force achieved at the beginning of the movement (PF1 is the main predictor of performance in jumping, although the RFDmax values and the ratio PF2/PF1 are also variables to be taken into account when analyzing the determinant factors of vertical jumping.

  5. THE EFFECTS OF THREE DIFFERENT REAR KNEE ANGLES ON KINEMATICS IN THE SPRINT START

    Directory of Open Access Journals (Sweden)

    C. Milanese

    2014-08-01

    Full Text Available The purpose of this study was to investigate the rear knee angle range in the set position that allows sprinters to reach greater propulsion on the rear block during the sprint start. Eleven university-track team sprinters performed the sprint start using three rear knee angle conditions: 90°, 115° and 135°. A motion capture system consisting of 8 digital cameras (250 Hz was used to record kinematic parameters at the starting block phase and the acceleration phase. The following variables were considered: horizontal velocity of the centre of mass (COM, COM height, block time, pushing time on the rear block, percentage of pushing time on the rear block, force impulse, push-off angle and length of the first two strides. The main results show that first, horizontal block velocity is significantly greater at 90° vs 115° and 135° rear knee angle (p<0.05 and p<0.001 respectively at block clearance and the first two strides; second, during the pushing phase, the percentage of pushing time of the rear leg is significantly greater at 90° vs 135° rear knee angle (p<0.01. No significant difference was found for block time among the conditions. These results indicate that block velocity is the main kinematic parameter affected by rear knee angle during the starting block phase and acceleration phase. Furthermore, the 90° rear knee angle allows for a better push-off of the rear leg than larger angles at the set position. The findings of this study provide some direction and useful practical advice in defining an efficient rear leg biomechanical configuration at the set position.

  6. Pacing and sprint performance in speed skating during a competitive season.

    Science.gov (United States)

    Muehlbauer, Thomas; Schindler, Christian; Panzer, Stefan

    2010-06-01

    This study assessed the effect of time spent in several race sectors (S) on finishing time and determined the variance in distribution of skating time and in total race time for official 1000-m sprint races conducted during a competitive season. Total race and sector times for the first 200 m (S1) and the following two 400-m laps (S2 and S3) of 34 female and 31 male elite speed skaters performed during a series of World Cup Meetings were analyzed. Overall, skaters started fast, reached their peak in S2, and slowed down in S3, irrespective of race category considered (eg, rank of athlete, number of race, altitude of rink, starting lane). Regression analyses revealed that spending a shorter fraction of time in the last (women in S3: B = 239.1; P < .0001; men in S3: B = 201.5; P < .0001) but not in the first (women in S1: B = -313.1; P < .0001; men in S1: B = -345.6; P < .0001) race sector is associated with a short total race time. Upper- compared with lower-ranked skaters varied less in competition-to-competition sector and total race times (women: 0.02 to 0.33 vs 0.02 to 0.51; men: 0.01 to 0.15 vs 0.02 to 0.57). This study confirmed that skaters adopted a fast start pacing strategy during official 1000-m sprint races. However, analyses indicate that shortening time in the closing but not in the starting sector is beneficial for finishing fast. In addition, findings suggest that lower-ranked skaters should concentrate training on lowering their competition-to-competition variability in sector times.

  7. Muscle oxygen changes following Sprint Interval Cycling training in elite field hockey players.

    Directory of Open Access Journals (Sweden)

    Ben Jones

    Full Text Available This study examined the effects of Sprint Interval Cycling (SIT on muscle oxygenation kinetics and performance during the 30-15 intermittent fitness test (IFT. Twenty-five women hockey players of Olympic standard were randomly selected into an experimental group (EXP and a control group (CON. The EXP group performed six additional SIT sessions over six weeks in addition to their normal training program. To explore the potential training-induced change, EXP subjects additionally completed 5 x 30s maximal intensity cycle testing before and after training. During these tests near-infrared spectroscopy (NIRS measured parameters; oxyhaemoglobin + oxymyoglobin (HbO2+ MbO2, tissue deoxyhaemoglobin + deoxymyoglobin (HHb+HMb, total tissue haemoglobin (tHb and tissue oxygenation (TSI % were taken. In the EXP group (5.34 ± 0.14 to 5.50 ± 0.14 m.s(-1 but not the CON group (pre = 5.37 ± 0.27 to 5.39 ± 0.30 m.s(-1 significant changes were seen in the 30-15 IFT performance. EXP group also displayed significant post-training increases during the sprint cycling: ΔTSI (-7.59 ± 0.91 to -12.16 ± 2.70%; ΔHHb+HMb (35.68 ± 6.67 to 69.44 ± 26.48 μM.cm; and ΔHbO2+ MbO2 (-74.29 ± 13.82 to -109.36 ± 22.61 μM.cm. No significant differences were seen in ΔtHb (-45.81 ± 15.23 to -42.93 ± 16.24. NIRS is able to detect positive peripheral muscle oxygenation changes when used during a SIT protocol which has been shown to be an effective training modality within elite athletes.

  8. Recovery benefits of using a heat and moisture exchange mask during sprint exercise in cold temperatures.

    Science.gov (United States)

    Seifert, John G; Frost, Jeremy; St Cyr, John A

    2017-01-01

    Breathing cold air can lead to bronchoconstriction and peripheral vasoconstriction, both of which could impact muscular performance by affecting metabolic demands during exercise. Successful solutions dealing with these physiological changes during exercise in the cold has been lacking; therefore, we investigated the influence of a heat and moisture exchange mask during exercise in the cold. There were three trial arms within this study: wearing the heat and moisture exchange mask during the rest periods in the cold, no-mask application during the rest periods in the cold, and a trial at room temperature (22°C). Eight subjects cycled in four 35 kJ sprint sessions with each session separated by 20 min rest period. Workload was 4% of body mass. Mean sprint times were faster with heat and moisture exchange mask and room temperature trial than cold, no-mask trial (133.8 ± 8.6, 134.9 ± 8.8, and 138.0 ± 8.4 s (p = 0.001)). Systolic blood pressure and mean arterial pressure were greater during the cold trial with no mask (15% and 13%, respectively), and heart rate was 10 bpm less during the third rest or recovery period during cold, no mask compared to the heat and moisture exchange mask and room temperature trials. Subjects demonstrated significant decreases in vital capacity and peak expiratory flow rate during the cold with no mask applied during the rest periods. These negative responses to cold exposure were alleviated by the use of a heat and moisture exchange mask worn during the rest intervals by minimizing cold-induced temperature stress on the respiratory system with subsequent maintenance of cardiovascular function.

  9. Generator exchange is associated with an increased rate of Sprint Fidelis lead failure.

    Science.gov (United States)

    Lovelock, Joshua D; Patel, Ayesha; Mengistu, Andenet; Hoskins, Michael; El-Chami, Mikhael; Lloyd, Michael S; Leon, Angel; DeLurgio, David; Langberg, Jonathan J

    2012-10-01

    The Medtronic Sprint Fidelis defibrillator lead is at an increased risk for failure and was recalled in October 2007. Approximately 268,000 leads were implanted, and more than 100,000 patients still have active Fidelis leads. A number of studies have examined the rate and clinical predictors of lead failure, but none has addressed the effect of an implantable cardioverter-defibrillator generator exchange on subsequent lead failure. Although the manufacturer asserts that "Sprint Fidelis performance after device change-out is similar to lead performance without device change-out," published data are lacking. To assess the effect of implantable cardioverter-defibrillator generator exchange on the rate of Fidelis lead failure. A chart review was conducted in patients who underwent implantation of a Fidelis lead. Patients with a functioning Fidelis lead at generator exchange were compared with controls with leads implanted for a comparable amount of time not undergoing ICD replacement. A total of 1366 patients received a Fidelis lead prior to the recall, of which 479 were still actively followed. Seventy-two patients with a functioning lead underwent generator exchange without lead replacement. Following generator replacement, 15 leads failed. Sixty percent of the Fidelis leads failed within 3 months. Generator exchange increased the rate of lead failure compared with matched controls (20.8% vs 2.54%; P exchange is associated with a higher than expected rate of Fidelis lead failure, often within 3 months. The risk-benefit ratio of Fidelis lead replacement at the time of generator exchange may be greater than appreciated. Copyright © 2012 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  10. PRONOUNCED MUSCLE DEOXYGENATION DURING SUPRAMAXIMAL EXERCISE UNDER SIMULATED HYPOXIA IN SPRINT ATHLETES

    Directory of Open Access Journals (Sweden)

    Kazuo Oguri

    2008-12-01

    Full Text Available The purpose of this study was to determine whether acute hypoxia alters the deoxygenation level in vastus lateralis muscle during a 30 s Wingate test, and to compare the muscle deoxygenation level between sprint athletes and untrained men. Nine male track sprinters (athletic group, VO2max 62.5 ± 4.1 ml/kg/min and 9 healthy untrained men (untrained group, VO2max 49.9 ± 5.2 ml·kg-1·min-1 performed a 30 s Wingate test under simulated hypoxic (FIO2 = 0.164 and PIO2 = 114 mmHg and normoxic conditions. During the exercise, changes in oxygenated hemoglobin (OxyHb in the vastus lateralis were measured using near infrared continuous wave spectroscopy. Decline in OxyHb, that is muscle deoxygenation, was expressed as percent change from baseline. Percutaneous arterial oxygen saturation (SpO2, oxygen uptake (VO2, and ventilation (VE were measured continuously. In both groups, there was significantly greater muscle deoxygenation, lower SpO2, lower peakVO2, and higher peakVE during supramaximal exercise under hypoxia than under normoxia, but no differences in peak and mean power output during the exercise. Under hypoxia, the athletic group experienced significantly greater muscle deoxygenation, lower SpO2, greater decrement in peakVO2 and increment in peakVE during the exercise than the untrained group. When the athletic and untrained groups were pooled, the increment of muscle deoxygenation was strongly correlated with lowest SpO2 in the 30 s Wingate test under hypoxia. These results suggest that acute exposure to hypoxia causes a greater degree of peripheral muscle deoxygenation during supramaximal exercise, especially in sprint athletes, and this physiological response would be explained mainly by lower arterial oxygen saturation

  11. Solar Features - Solar Flares

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A solar flare is a short-lived sudden increase in the intensity of radiation emitted in the neighborhood of sunspots. For many years it was best monitored in the...

  12. TOEFL Junior® Design Framework. TOEFL Junior® Research Report. TOEFL JR-02. ETS Research Report No. RR-15-13

    Science.gov (United States)

    So, Youngsoon; Wolf, Mikyung Kim; Hauck, Maurice C.; Mollaun, Pamela; Rybinski, Paul; Tumposky, Daniel; Wang, Lin

    2015-01-01

    This paper presents the theoretical and empirical foundations of the "TOEFL Junior"® assessment and its development process. The TOEFL Junior test was developed to address the increasing need for objective measures of English language proficiency for young adolescent learners, who are being introduced to English as a second or foreign…

  13. Social skills and loneliness in junior high school students

    OpenAIRE

    Kanayama, Motoharu; Ono, Masahiko; Ohashi, Tsutomu; Tsujimoto, Yuichi; Oi, Shizuyo; Matsui, Kayoko; Tsujimoto, Ikuhiro; Yoshida, Hatsuko

    2003-01-01

    The purposes of this study were to examine the relationship between social skills and loneliness, and to contribute to prevention and intervention of loneliness in junior high school students. Questionnaires were administered to 83 students (45 males and 38 females). Correlation analysis showed that loneliness score was negatively related to the scores of peer reinforcement, social initiation, conflict resolution and assertion skills, and also positively related to the score of withdrawal beh...

  14. Multidisciplinary Mentoring Programs to Enhance Junior Faculty Research Grant Success.

    Science.gov (United States)

    Freel, Stephanie A; Smith, Paige C; Burns, Ebony N; Downer, Joanna B; Brown, Ann J; Dewhirst, Mark W

    2017-10-01

    Junior faculty face challenges in establishing independent research careers. Declining funding combined with a shift to multidisciplinary, collaborative science necessitates new mentorship models and enhanced institutional support. Two multidisciplinary mentorship programs to promote grant success for junior faculty were established at the Duke University School of Medicine beginning in 2011. These four-month programs-the Path to Independence Program (PtIP) for National Institutes of Health (NIH) R applicants and the K Club for NIH K applicants-use multiple senior faculty mentors and professional grant-writing staff to provide a 20-hour joint curriculum comprising a series of lectures, hands-on workshops, career development counseling, peer groups, and an internal study section. In March 2016, the authors analyzed the success rate for all NIH grants submitted by participants since program enrollment. In a 2015 postprogram survey, participants rated their feelings of support and competency across six skill factors. From October 2011 to March 2016, the programs engaged 265 senior faculty mentors, 145 PtIP participants, and 138 K Club participants. Success rates for NIH grant applications were 28% (61 awards/220 decisions) for PtIP participants-an increase over the 2010 Duke University junior faculty baseline of 11%-and 64% (38/59) for K Club participants. Respondents reported significantly increased feelings of support and self-ratings for each competency post program. The authors plan to expand the breadth of both the mentorship pool and faculty served. Broad implementation of similar programs elsewhere could bolster success, satisfaction, and retention of junior faculty investigators.

  15. Structuring Naval Special Warfare junior officer professional military education

    OpenAIRE

    Donovan, Thomas A.

    2007-01-01

    Naval Special Warfare does not currently have a designated career path for an officer that requires professional military education (PME) for SEAL junior officers after the rank of Ensign (O-1) and before the rank of Lieutenant Commander (O-4). There currently is interest in this subject matter at the Naval Special Warfare Command and Center. SEAL officers increasingly hold key leadership positions and influence critical decisions in the execution of national strategy. This growing respo...

  16. Junior Officer Competency Model: Research Results and Applications

    Science.gov (United States)

    1988-03-01

    equal numbers of positive and nega- tive behavioral events, so that variation in this fifty-fifty distribution reflected the information volunteered ...represent effective bahavior . The early piloting of the ALPE produced a number of examples of this phenomena. Second, and more significantly, the junior...deficiencies of experienced NCOs , Get a senior officer to change an inappropriate order 6. Job Involvement Volunteer for new assignments Personally

  17. Logistics Junior Officer Development in a Period of Persistent Conflict

    Science.gov (United States)

    2013-05-23

    JUNIOR OFFICER DEVELOPMENT IN A PERIOD OF PERSISTENT CONFLICT 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S...have less time 38Respondent 10 Email, March 30, 2012. 39Major General Edward C. Cardon , “Thoughts for SAMS Students,”(lecture, Marshall Auditorium...www.amazon.com/John-C.-Maxwell (accessed 18 April 2013). Lectures: Cardon , Edward. “Thoughts for SAMS Students.” Address to School of Advanced Military

  18. Antecedents of Overtime Work: The Case of Junior Academics

    OpenAIRE

    Frei, Irina; Grund, Christian

    2017-01-01

    Despite the ongoing public debate about precarious working conditions in academia, there is only little evidence on working hours and overtime work for the group of (non-tenured) junior academics. By using unique longitudinal survey data on the occupational situation and careers of doctoral students and doctorate holders in STEM fields in Germany, we explore potential antecedents of overtime. We find that overtime hours are less pronounced among firm employees holding a doctorate and among po...

  19. Differences in Physical Capacity Between Junior and Senior Australian Footballers.

    Science.gov (United States)

    Kelly, Stephen J; Watsford, Mark L; Austin, Damien J; Spurrs, Rob W; Pine, Matthew J; Rennie, Michael J

    2017-11-01

    Kelly, SJ, Watsford, ML, Austin, DJ, Spurrs, RW, Pine, MJ, and Rennie, MJ. Differences in physical capacity between junior and senior Australian footballers. J Strength Cond Res 31(11): 3059-3066, 2017-The purpose of this study was to profile and compare anthropometric and physical capacities within elite junior and senior Australian football (AF) players of various chronological ages and stages of athletic development. Seventy-nine players, including junior and senior AF players from one professional club, were profiled using 11 assessments. Junior players were divided into 2 groups based on chronological age (under 16 and 18 years) and senior players according to years since drafted to a professional AF team (1-2 years, 3-7 years, and 8+ years). Parametric data were assessed using a 1-way analysis of variance (ANOVA), whereas nonparametric data were assessed using a Kruskal-Wallis ANOVA. The magnitude difference between players was measured using the Hopkins' effect size (ES). Significant differences were evident between under-16 players and all senior player groups for anthropometric (p = 0.001-0.019/ES = 1.25-2.13), absolute strength (p = 0.001-0.01/ES = 1.82-4.46), and relative strength (p = 0.001-0.027/ES = 0.84-3.55). The under-18 players displayed significantly lower absolute strength (p = 0.001-0.012/ES = 1.82-3.79) and relative strength (p = 0.001-0.027/ES = 0.85-4.00) compared with the 3-7 and 8+ players. Significant differences were evident between the under-16 players and senior player groups for explosive jumping and throwing tests (p = 0.001-0.017/ES = 1.03-2.99). Minimal differences were evident between all player groups for running assessments; however, the under-16 players were significantly slower compared with the 8+ players for the 3-km time trial (p senior AF players.

  20. Solar storms; Tormentas solares

    Energy Technology Data Exchange (ETDEWEB)

    Collaboration: Pereira Cuesta, S.; Pereira Pagan, B.

    2016-08-01

    Solar storms begin with an explosion, or solar flare, on the surface of the sun. The X-rays and extreme ultraviolet radiation from the flare reach the Earths orbit minutes later-travelling at light speed. The ionization of upper layers of our atmosphere could cause radio blackouts and satellite navigation errors (GPS). Soon after, a wave of energetic particles, electrons and protons accelerated by the explosion crosses the orbit of the Earth, and can cause real and significant damage. (Author)

  1. IMPLEMENTASI PROGRAM JUNIOR ACHIEVEMENT BE ENTREPRENEURIAL PADA MATA PELAJARAN KEWIRAUSAHAAN

    Directory of Open Access Journals (Sweden)

    Arifiyah Arifiyah

    2017-10-01

    Full Text Available This study aimed to describe and analyze the implementation of Junior Achievement Be Entrepreneurial program on entrepreneurship subjects in SMA Negeri 3 Semarang. The approach used is qualitative, descriptive methods, and case study research design. The collection of data through observation, interviews and document study. The results showed that the activities of the program before learning that socialization programs, training of trainers and teachers, and planning. Implementation of learning for 8 sessions consist of an introduction to the program, the pre-test, materials, post-test, and questionnaire. Criteria for graduation students follow a program of pre-test and post-test, attendance, student workbook, business plan proposal, and questionnaires with graduation status and succes succes complete and certified. After the implementation of learning there are extra-curricular activities or activities outside class called weekly meetings for the preparation of student company competition. Results graduation are 95.93% and achievements gained from regional, national, and Asia-Pacific. The material taught include the motivation of entrepreneurship, business ideas, who my customers, what is my superiority, business ethics, and business plans. Learning strategy use of small group discussions. Parties directly invol ved, namely students, teachers and trainers, while the other parties involved, namely the Junior Achievement Indonesia, the school, the Department of Education and Citi Bank. Conclusion Junior Achievement Be Entrepreneurial program that is good, decent, and can be disseminated.

  2. Changing the Culture of Science Communication Training for Junior Scientists

    Science.gov (United States)

    Bankston, Adriana; McDowell, Gary S.

    2018-01-01

    Being successful in an academic environment places many demands on junior scientists. Science communication currently may not be adequately valued and rewarded, and yet communication to multiple audiences is critical for ensuring that it remains a priority in today’s society. Due to the potential for science communication to produce better scientists, facilitate scientific progress, and influence decision-making at multiple levels, training junior scientists in both effective and ethical science communication practices is imperative, and can benefit scientists regardless of their chosen career path. However, many challenges exist in addressing specific aspects of this training. Principally, science communication training and resources should be made readily available to junior scientists at institutions, and there is a need to scale up existing science communication training programs and standardize core aspects of these programs across universities, while also allowing for experimentation with training. We propose a comprehensive core training program be adopted by universities, utilizing a centralized online resource with science communication information from multiple stakeholders. In addition, the culture of science must shift toward greater acceptance of science communication as an essential part of training. For this purpose, the science communication field itself needs to be developed, researched and better understood at multiple levels. Ultimately, this may result in a larger cultural change toward acceptance of professional development activities as valuable for training scientists. PMID:29904538

  3. [Risk of injury in and adolescent and junior competitive karate].

    Science.gov (United States)

    Müller-Rath, R; Miltner, O; Mamarvar, M; Mumme, T

    2005-12-01

    Increasing professionalism in competitive karate has led to a specific injury pattern. The aim of our study was to investigate the injury pattern in junior competitive karate and to evaluate the prophylactic effect of fist padding. During the 4 (th) Junior World Championships of the World Karate Confederation (WKC) 2004 235 karate fights were observed and injury-related data were recorded. Fist padding was used in 183 fights, 52 fights were carried out without. In 22 % of all fights we saw an injury. Most of them were mild injuries of the head and face: 32 bruises of the face (13 with epistaxis), 7 facial lacerations and 3 concussions (mild brain injury). 14 fights were stopped due to an injury. Only in the category male 18 - 20 years a higher rate of injuries was seen without fist padding (shobu ippon) compared to shobu sanbon (with fist padding). The injury pattern of junior competitive karate is comparable to senior karate. Fist padding does not generally reduce the incidence or severity of injuries.

  4. Musculoskeletal Injuries and Training Patterns in Junior Elite Orienteering Athletes

    Directory of Open Access Journals (Sweden)

    Lilian Roos

    2015-01-01

    Full Text Available Findings about the relation between musculoskeletal injuries and training patterns in orienteering athletes are sparse. Therefore, the musculoskeletal injuries and training patterns of 31 Swiss elite orienteering athletes aged 18-19 years were analyzed in a retrospective study. Individual training diaries and medical records were used to assess training data and injury history, respectively. Group comparisons and a multiple linear regression (MLR were performed for statistical analysis. The junior elite orienteering athletes performed 7.38 ± 2.00 training sessions weekly, with a total duration of 455.75 ± 98.22 minutes. An injury incidence rate (IIR of 2.18 ± 2.13 injuries per 1000 hours of training was observed. The lower extremity was affected in 93% of all injuries, and the knee (33% was the most commonly injured location. The MLR revealed that gender and six training variables explained 60% of the variance in the injury severity index in this study. Supported by the low IIR in the observed age group, the training protocol of the junior elite orienteering athletes was generally adequate. In comparison to elite track, marathon, and orienteering athletes, the junior elite athletes performed less high-intensity interval training (HIIT. However, more frequent HIIT seems to be a protective factor against injuries.

  5. Changing the Culture of Science Communication Training for Junior Scientists.

    Science.gov (United States)

    Bankston, Adriana; McDowell, Gary S

    2018-01-01

    Being successful in an academic environment places many demands on junior scientists. Science communication currently may not be adequately valued and rewarded, and yet communication to multiple audiences is critical for ensuring that it remains a priority in today's society. Due to the potential for science communication to produce better scientists, facilitate scientific progress, and influence decision-making at multiple levels, training junior scientists in both effective and ethical science communication practices is imperative, and can benefit scientists regardless of their chosen career path. However, many challenges exist in addressing specific aspects of this training. Principally, science communication training and resources should be made readily available to junior scientists at institutions, and there is a need to scale up existing science communication training programs and standardize core aspects of these programs across universities, while also allowing for experimentation with training. We propose a comprehensive core training program be adopted by universities, utilizing a centralized online resource with science communication information from multiple stakeholders. In addition, the culture of science must shift toward greater acceptance of science communication as an essential part of training. For this purpose, the science communication field itself needs to be developed, researched and better understood at multiple levels. Ultimately, this may result in a larger cultural change toward acceptance of professional development activities as valuable for training scientists.

  6. NIR tracking assists sports medicine in junior basketball training

    Science.gov (United States)

    Paeglis, Roberts; Bluss, Kristaps; Rudzitis, Andris; Spunde, Andris; Brice, Tamara; Nitiss, Edgars

    2011-07-01

    We recorded eye movements of eight elite junior basketball players. We hypothesized that a more stable gaze is correlated to a better shot rate. Upon preliminary testing we invited male juniors whose eyes could be reliably tracked in a game situation. To these ends, we used a head-mounted video-based eye tracker. The participants had no record of ocular or other health issues. No significant differences were found between shots made with and without the tracker cap, Paired samples t-test yielded p= .130 for the far and p=..900 > .050 for the middle range shots. The players made 40 shots from common far and middle range locations, 5 and 4 meters respectively for aged 14 years As expected, a statistical correlation was found between gaze fixation (in milliseconds) for the far and middle range shot rates, r=.782, p=.03. Notably, juniors who fixated longer before a shot had a more stable fixation or a lower gaze dispersion (in tracker's screen pixels), r=-.786, p=.02. This finding was augmented by the observation that the gaze dispersion while aiming at the basket was less (i.e., gaze more stable) in those who were more likely to score. We derived a regression equation linking fixation duration to shot success. We advocate infra-red eye tracking as a means to monitor player selection and training success.

  7. Perspectives on the working hours of Australian junior doctors.

    Science.gov (United States)

    Glasgow, Nicholas J; Bonning, Michael; Mitchell, Rob

    2014-01-01

    The working hours of junior doctors have been a focus of discussion in Australia since the mid-1990s. Several national organizations, including the Australian Medical Association (AMA), have been prominent in advancing this agenda and have collected data (most of which is self-reported) on the working hours of junior doctors over the last 15 years. Overall, the available data indicate that working hours have fallen in a step-wise fashion, and AMA data suggest that the proportion of doctors at high risk of fatigue may be declining. It is likely that these changes reflect significant growth in the number of medical graduates, more detailed specifications regarding working hours in industrial agreements, and a greater focus on achieving a healthy work-life balance. It is notable that reductions in junior doctors' working hours have occurred despite the absence of a national regulatory framework for working hours. Informed by a growing international literature on working hours and their relation to patient and practitioner safety, accreditation bodies such as the Australian Commission on Safety and Quality in Health Care (ACSQHC) and the Australian Medical Council (AMC) are adjusting their standards to encourage improved work and training practices.

  8. Cognitive Function and Kidney Disease: Baseline Data From the Systolic Blood Pressure Intervention Trial (SPRINT).

    Science.gov (United States)

    Weiner, Daniel E; Gaussoin, Sarah A; Nord, John; Auchus, Alexander P; Chelune, Gordon J; Chonchol, Michel; Coker, Laura; Haley, William E; Killeen, Anthony A; Kimmel, Paul L; Lerner, Alan J; Oparil, Suzanne; Saklayen, Mohammad G; Slinin, Yelena M; Wright, Clinton B; Williamson, Jeff D; Kurella Tamura, Manjula

    2017-09-01

    Chronic kidney disease is common and is associated with cardiovascular disease, cerebrovascular disease, and cognitive function, although the nature of this relationship remains uncertain. Cross-sectional cohort using baseline data from the Systolic Blood Pressure Intervention Trial (SPRINT). Participants in SPRINT, a randomized clinical trial of blood pressure targets in older community-dwelling adults with cardiovascular disease, chronic kidney disease, or high cardiovascular disease risk and without diabetes or known stroke, who underwent detailed neurocognitive testing in the cognition substudy, SPRINT-Memory and Cognition in Decreased Hypertension (SPRINT-MIND). Urine albumin-creatinine ratio (ACR) and estimated glomerular filtration rate (eGFR). Cognitive function, a priori defined as 5 cognitive domains based on 11 cognitive tests using z scores, and abnormal white matter volume quantified by brain magnetic resonance imaging. Of 9,361 SPRINT participants, 2,800 participated in SPRINT-MIND and 2,707 had complete data; 637 had brain imaging. Mean age was 68 years, 37% were women, 30% were black, and 20% had known cardiovascular disease. Mean eGFR was 70.8±20.9mL/min/1.73m 2 and median urine ACR was 9.7 (IQR, 5.7-22.5) mg/g. In adjusted analyses, higher ACR was associated with worse global cognitive function, executive function, memory, and attention, such that each doubling of urine ACR had the same association with cognitive performance as being 7, 10, 6, and 14 months older, respectively. Lower eGFR was independently associated with worse global cognitive function and memory. In adjusted models, higher ACR, but not eGFR, was associated with larger abnormal white matter volume. Cross-sectional only, no patients with diabetes were included. In older adults, higher urine ACR and lower eGFR have independent associations with global cognitive performance with different affected domains. Albuminuria concurrently identifies a higher burden of abnormal brain

  9. Isometric Mid-Thigh Pull Correlates With Strength, Sprint, and Agility Performance in Collegiate Rugby Union Players.

    Science.gov (United States)

    Wang, Ran; Hoffman, Jay R; Tanigawa, Satoru; Miramonti, Amelia A; La Monica, Michael B; Beyer, Kyle S; Church, David D; Fukuda, David H; Stout, Jeffrey R

    2016-11-01

    Wang, R, Hoffman, JR, Tanigawa, S, Miramonti, AA, La Monica, MB, Beyer, KS, Church, DD, Fukuda, DH, and Stout, JR. Isometric mid-thigh pull correlates with strength, sprint, and agility performance in collegiate rugby union players. J Strength Cond Res 30(11): 3051-3056, 2016-The purpose of this investigation was to examine the relationships between isometric mid-thigh pull (IMTP) force and strength, sprint, and agility performance in collegiate rugby union players. Fifteen members of a champion-level university's club rugby union team (mean ± SD: 20.67 ± 1.23 years, 1.78 ± 0.06 m, and 86.51 ± 14.18 kg) participated in this investigation. One repetition maximum (1RM) squat, IMTP, speed (40 m sprint), and agility (proagility test and T-test) were performed during 3 separate testing sessions. Rate of force development (RFD) and force output at 30, 50, 90, 100, 150, 200, and 250 milliseconds of IMTP, as well as the peak value were determined. Pearson product-moment correlation analysis was used to examine the relationships between these measures. Performance in the 1RM squat was significantly correlated to the RFD between 90 and 250 milliseconds from the start of contraction (r's ranging from 0.595 to 0.748), and peak force (r = 0.866, p ≤ 0.05). One repetition maximum squat was also correlated to force outputs between 90 and 250 milliseconds (r's ranging from 0.757 to 0.816, p ≤ 0.05). Sprint time over the first 5 m in the 40 m sprint was significantly (p ≤ 0.05) correlated with peak RFD (r = -0.539) and RFD between 30 and 50 milliseconds (r's = -0.570 and -0.527, respectively). Time for the proagility test was correlated with peak RFD (r = -0.523, p ≤ 0.05) and RFD between 30 and 100 milliseconds (r's ranging from -0.518 to -0.528, p's strength, agility, and sprint performance. Future studies should examine IMTP as a potential tool to monitor athletic performance during the daily training of rugby union players.

  10. The effects of a single whole body cryotherapy exposure on physiological, performance and perceptual responses of professional academy soccer players following repeated sprint exercise

    OpenAIRE

    Russell, Mark; Birch, Jack; Love, Thomas; Cook, Christian; Bracken, Richard M.; Taylor, Tom; Swift, Eamon; Cockburn, Emma; Finn, Charlie; Cunningham, Daniel; Wilson, Laura; Kilduff, Liam P.

    2017-01-01

    In professional youth soccer players, the physiological, performance and perceptual effects of a single whole body cryotherapy (WBC) session performed shortly after repeated sprint exercise were investigated. In a randomized, counter-balanced and crossover design, 14 habituated English Premier League academy soccer players performed 15 x 30 m sprints (each followed by a 10 m forced deceleration) on two occasions. Within 20 min of exercise cessation, players entered a WBC chamber (Cryo: 30 s a...

  11. SAFIPA-Meraka Institute code-sprints program; a mechanism to enhance the development capacity of emerging developers – observations and lessons learned

    CSIR Research Space (South Africa)

    Coetzee, L

    2010-05-01

    Full Text Available -MERAKA code-sprints program, a possibility for development is identified. NAP, an initiative to enhance inclusion and empower persons with disabilities, has shown that initiatives need to come from within the community to succeed. A popular slogan... ownership of development efforts. This paper investigates the feasibility of the “ICT for Society through Society” paradigm at the hand of the SAFIPA-MERAKA code-sprints program, an analysis of the Information and Communications Technology...

  12. Relación entre la fuerza máxima en squat y acciones de salto, sprint y golpeo de balón. (Relationship among maximal strength in squat exercise, jump, sprint and kicking ball performance.

    Directory of Open Access Journals (Sweden)

    Alfredo Arija Blázquez

    2008-01-01

    Full Text Available ResumenEl objetivo del presente estudio fue analizar las posibles relaciones entre la fuerza máxima en squat y accionesexplosivas de salto, sprint y golpeo de balón. Para ello, se contó con una muestra formada por estudiantes de Ciencias del Deporte (N= 16; 19,6 ± 1,7 años de sexo masculino (con escasa experiencia en el entrenamiento de fuerza, que llevaron a cabo un test de 1RM en squat (calculándose el peso levantado, la fuerza media total y la fuerza dinámica máxima, tests de salto vertical (SJ, CMJ y CMJa, un test de sprint de 20 m (con mediciones de tiempo cada 5 m, y un test de golpeo con el pie donde se calculaba la velocidad del balón. Se encontraron coeficientes de correlación moderados (entre 0,52 y 0,67 y significativos de las medidas de fuerza máxima y las alturas de salto, mientras que los coeficientes obtenidos entre los tiempos de sprint y dichas medidas de fuerza máxima se situaron entre -0,06 y -0,32, no siendo ninguno de ellos significativo; al igual que tampoco fueron significativos los coeficientes de correlación de las medidas de fuerza máxima y la velocidad de tiro, se situaron entre 0,25 y 0,34. Por tanto, la relación entre la fuerza máxima en squat y la altura de salto en sujetos con escasa experiencia en el entrenamiento de fuerza resultó moderada, mientras que no parece existir relación con el tiempo de sprint y la velocidad de tiro.AbstractThe purpose of the present study was to analyze the possible relationships between maximal strength insquat exercise and jump, sprint and kicking ball actions. Sixteen males sport science students (19,6 ± 1,7years, with little experience in strength training, performed a 1RM in squat exercise (from which liftedweight, the total average- and maximal-dynamic strength was assessed, vertical jump (SJ, CMJ and CMJa, a 20 m sprint test (with time measurement every 5 m, and a kicking ball test where the velocity of the ball was calculated. Moderate (0,52 - 0,67 and

  13. Increased oxidative stress and anaerobic energy release, but blunted Thr172-AMPKα phosphorylation, in response to sprint exercise in severe acute hypoxia in humans.

    Science.gov (United States)

    Morales-Alamo, David; Ponce-González, Jesús Gustavo; Guadalupe-Grau, Amelia; Rodríguez-García, Lorena; Santana, Alfredo; Cusso, Maria Roser; Guerrero, Mario; Guerra, Borja; Dorado, Cecilia; Calbet, José A L

    2012-09-01

    AMP-activated protein kinase (AMPK) is a major mediator of the exercise response and a molecular target to improve insulin sensitivity. To determine if the anaerobic component of the exercise response, which is exaggerated when sprint is performed in severe acute hypoxia, influences sprint exercise-elicited Thr(172)-AMPKα phosphorylation, 10 volunteers performed a single 30-s sprint (Wingate test) in normoxia and in severe acute hypoxia (inspired Po(2): 75 mmHg). Vastus lateralis muscle biopsies were obtained before and immediately after 30 and 120 min postsprint. Mean power output and O(2) consumption were 6% and 37%, respectively, lower in hypoxia than in normoxia. O(2) deficit and muscle lactate accumulation were greater in hypoxia than in normoxia. Carbonylated skeletal muscle and plasma proteins were increased after the sprint in hypoxia. Thr(172)-AMPKα phosphorylation was increased by 3.1-fold 30 min after the sprint in normoxia. This effect was prevented by hypoxia. The NAD(+)-to-NADH.H(+) ratio was reduced (by 24-fold) after the sprints, with a greater reduction in hypoxia than in normoxia (P exercise in human skeletal muscle is altered in severe acute hypoxia, which abrogated Thr(172)-AMPKα phosphorylation, likely due to lower LKB1 activation by SIRT1.

  14. Performance and anthropometric characteristics of prospective elite junior Australian footballers: a case study in one junior team.

    Science.gov (United States)

    Veale, James P; Pearce, Alan J; Koehn, Stefan; Carlson, John S

    2008-04-01

    The aim of the study was to compare anthropometric and physical performance data of players who were selected for a Victorian elite junior U18 Australian rules football squad. Prior to the selection of the final training squad, 54 players were assessed using a battery of standard anthropometric and physical performance tests. Multivariate analysis (MANOVA) showed significant (pcharacteristics can be observed that discriminate between players selected and non-selected, and demonstrates the value of physical fitness testing within the talent identification process of junior (16-18 years) players for squad and/or team selection. Based on MANOVA results, the findings from this study suggest team selection appeared to be related to a generally higher performance across the range of tests. Further, age was not a confounding variable as players selected tended to be younger than those non-selected. These findings reflect the general consensus that, in state-based junior competition, there is evidence of promoting overall player development, selecting those who are generally able to fulfil a range of positions and selecting players on their potential.

  15. RELEVANCE OF USE OF MULTIMEDIA IN ORDER TO PREVENT JUNIOR PUPILS’ AGGRESSIVE BEHAVIOUR

    Directory of Open Access Journals (Sweden)

    Natalia V. Oleksiuk

    2014-10-01

    Full Text Available The article analyzes the problem of aggressive behaviour of junior pupils and reasons for its occurrence. There are determined advantages of multimedia use in the prevention of aggressive behaviour of junior pupils and described types of multimedia, which should be used to work with pupils. Problem of aggressive behaviour of junior pupils become one of the main problems of our society. As noted by the most researchers, one of the cause of aggressive behaviour of junior pupils is media, the use of video games, watching movies, cartoons that provoke aggression. One of the important areas of prevention of aggressive behaviour of junior pupils is competence improvement of teachers, social workers and psychologists on the use of multimedia in social and educational classes for junior pupils.

  16. Mapping of Junior High School Students’ Social Relation Problem and the Needed Assisting Model

    OpenAIRE

    Arbin Janu Setiyowati; Marthen Pali; Bambang Budi Wiyono; Triyono

    2017-01-01

    This research aims to describe Junior High School students’ social relation problem and the needed assisting model. This research used descriptive design with survey method. The subjects of this research were Junior High School students in the three cities in East Java. This research used purposive sampling as well. The data was collected by using questionnaire. The data analysis was conducted descriptively. This research found that Junior High School students’ social relation problems includ...

  17. PROGNOSTIC QUALITY OF MOTOR AND MORPHOLOGICAL FACTORS IN RELATION TO TRACK AND FIELD EVENTS OF SPRINT AND JUMPING TYPE

    Directory of Open Access Journals (Sweden)

    Kemal Idrizović

    2009-11-01

    Full Text Available Assessment of the impact of motor manifestations and morphological features on the quality in the realization of track and field events of sprint and jumping type was the main issue of this research. The aim of the paper was to establish the impact of the ap- plied predictor systems of variables, motor and morphological ones, on the criteria va- riables, the results in track and field events: long jump and 60m sprint event. The results obtained in this research lead to the conclusion that this type of track and field events, or the quality of their realization in the motor sense mostly depends on the locomotive complexes of similar structure. However, in the morphological sense, such impact is va- riable.

  18. Final Project Closeout Report for Sprint Hydrogen Fuel Cell (HFC) Deployment Project in California, Gulf Coast and Eastern Seaboard Markets

    Energy Technology Data Exchange (ETDEWEB)

    Kenny, Kevin [Sprint, Reston, VA (United States); Bradley, Dwayne [Burns & McDonnell, Kansas City, MO (United States)

    2015-09-01

    Sprint is one of the telecommunications industry leaders in the deployment of hydrogen fuel cell (HFC) systems to provide backup power for their mission critical wireless network facilities. With several hundred fuel cells commissioned in California, states in the gulf coast region, and along the upper eastern seaboard. A strong incentive for advancing the integration of fuel cells into the Sprint network came through the award of a Department of Energy (DOE) grant focused on Market Transformation activities for project (EE0000486). This grant was funded by the 2009 American Recovery and Reinvestment Act (ARRA). The funding provided by DOE ($7.295M) was allocated to support the installation of 260 new HFC systems, equipped with an on-site refillable Medium Pressure Hydrogen Storage Solution (MPHSS), as well as for the conversion of 21 low pressure hydrogen systems to the MPHSS, in hopes of reducing barriers to market acceptance.

  19. Endurance, aerobic high-intensity, and repeated sprint cycling performance is unaffected by normobaric "Live High-Train Low"

    DEFF Research Database (Denmark)

    Bejder, Jacob; Andersen, Andreas Breenfeldt; Buchardt, Rie

    2017-01-01

    The aim was to investigate whether 6 weeks of normobaric "Live High-Train Low" (LHTL) using altitude tents affect highly trained athletes incremental peak power, 26-km time-trial cycling performance, 3-min all-out performance, and 30-s repeated sprint ability. In a double-blinded, placebo......-controlled cross-over design, seven highly trained triathletes were exposed to 6 weeks of normobaric hypoxia (LHTL) and normoxia (placebo) for 8 h/day. LHTL exposure consisted of 2 weeks at 2500 m, 2 weeks at 3000 m, and 2 weeks at 3500 m. Power output during an incremental test, ~26-km time trial, 3-min all...... conducted in a double-blinded, placebo-controlled cross-over design do not affect power output during an incremental test, a ~26-km time-trial test, or 3-min all-out exercise in highly trained triathletes. Furthermore, 30 s of repeated sprint ability was unaltered....

  20. Beneficial Effects of New Zealand Blackcurrant Extract on Maximal Sprint Speed during the Loughborough Intermittent Shuttle Test

    Directory of Open Access Journals (Sweden)

    Mark ET Willems

    2016-08-01

    Full Text Available New Zealand blackcurrant (NZBC extract has been shown to enhance high-intensity intermittent treadmill running. We examined the effects of NZBC extract during the Loughborough Intermittent Shuttle Test (LIST which involves 5 × 15 min blocks with intermittent 15-m maximal sprints, interspersed by moderate and high-intensity running to simulate team sport activity, and a subsequent run to exhaustion. Thirteen males (age: 22 ± 1 year, V ˙ O 2 max : 50 ± 5 mL·kg−1·min−1 participated in three indoor sessions (T: 24 ± 3 °C, humidity: 52% ± 9%. In the first session, a multistage fitness test was completed to determine peak running speed and estimate V ˙ O 2 max . Participants consumed NZBC extract in capsules (300 mg·day−1 CurraNZ™ or placebo (PL (300 mg·day−1 microcrystalline cellulose M102 for seven days in a double-blind, randomized, cross-over design (wash-out at least seven days. NZBC extract did not affect average 15-m sprint times in each block. NZBC reduced slowing of the fastest sprint between block 1 and 5 (PL: 0.12 ± 0.07 s; NZBC: 0.06 ± 0.12 s; p < 0.05. NZBC extract had no effect on heart rate, vertical jump power, lactate and time to exhaustion (PL: 13.44 ± 8.09 min, NZBC: 15.78 ± 9.40 min, p > 0.05. However, eight participants had higher running times to exhaustion when consuming NZBC extract. New Zealand blackcurrant extract may enhance performance in team sports with repeated maximal sprints.

  1. Precision Medicine for Hypertension Management in Chronic Kidney Disease: Relevance of SPRINT for Therapeutic Targets in Nondiabetic Renal Disease.

    Science.gov (United States)

    Ruzicka, Marcel; Burns, Kevin D; Hiremath, Swapnil

    2017-05-01

    In this review we evaluate the literature to determine if lower blood pressure (BP) targets are beneficial for patients with nondiabetic chronic kidney disease (CKD). Modification of Diet in Renal Disease (MDRD), African American Study of Kidney Disease and Hypertension (AASK), and Ramipril Efficacy in Nephropathy-2 (REIN-2), designed to assess the benefit of lower BP on progression of nondiabetic CKD, generally came to the same negative conclusion. They were not designed and powered to assess an effect of lower BP on cardiovascular outcomes. The Systolic Blood Pressure Intervention Trial (SPRINT) was the first trial designed and powered to address this issue, and showed a clear benefit of a lower targeted and achieved BP. SPRINT did not show any renal benefits from lower BP, and it was not designed to assess this outcome, and it enrolled patients with less "renal risk" per se. A distinguishing feature of SPRINT compared with other large trials is that it highlighted the importance of precise BP measurement methods in defining targets in hypertension treatment. Accordingly, we propose that SPRINT is truly a "game-changing" clinical trial that sets the bar for management of hypertension in select patients with nondiabetic CKD. In these patients, systolic BP target depends critically on the BP measurement method: < 140 mm Hg when derived from 3 readings using a mercury sphygmomanometer after 5 minutes of rest, < 130 mm Hg when calculated from at a minimum of 3 readings using an automated oscillometric device, and < 120 mm Hg when taken using an automated oscillometric device after 5 minutes of unattended rest. Copyright © 2017 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  2. Acute and Post-Exercise Physiological Responses to High-Intensity Interval Training in Endurance and Sprint Athletes.

    Science.gov (United States)

    Cipryan, Lukas; Tschakert, Gerhard; Hofmann, Peter

    2017-06-01

    The purpose of the presented study was to compare acute and post-exercise differences in cardiorespiratory, metabolic, cardiac autonomic, inflammatory and muscle damage responses to high-intensity interval exercise (HIIT) between endurance and sprint athletes. The study group consisted of sixteen highly-trained males (age 22.1 ± 2.5 years) participating in endurance (n = 8) or sprint (n = 8) sporting events. All the participants underwent three exercise sessions: short HIIT (work interval duration 30s), long HIIT (3min) and constant load exercise (CE). The exercise interventions were matched for mean power, total time and in case of HIIT interventions also for work-to-relief ratio. The acute cardiorespiratory (HR, V̇ O 2 , RER) and metabolic (lactate) variables as well as the post-exercise changes (up to 3 h) in the heart rate variability, inflammation (interleukin-6, leucocytes) and muscle damage (creatine kinase, myoglobin) were monitored. Endurance athletes performed exercise interventions with moderately (CE) or largely (both HIIT modes) higher mean V̇ O 2 . These differences were trivial/small when V̇ O 2 was expressed as a percentage of V̇ O 2max . Moderately to largely lower RER and lactate values were found in endurance athletes. Markers of cardiac autonomic regulation, inflammation and muscle damage did not reveal any considerable differences between endurance and sprint athletes. In conclusions, endurance athletes were able to perform both HIIT formats with increased reliance on aerobic metabolic pathways although exercise intensity was identical in relative terms for all the participants. However, other markers of the acute and early post-exercise physiological response to these HIIT interventions indicated similarities between endurance and sprint athletes.

  3. Comparison of Cardiorespiratory and Metabolic Responses in Kettlebell High-Intensity Interval Training Versus Sprint Interval Cycling.

    Science.gov (United States)

    Williams, Brian M; Kraemer, Robert R

    2015-12-01

    The purpose of this study was to determine the effectiveness of a novel exercise protocol we developed for kettlebell high-intensity interval training (KB-HIIT) by comparing the cardiorespiratory and metabolic responses to a standard sprint interval cycling (SIC) exercise protocol. Eight men volunteered for the study and completed 2 preliminary sessions, followed by two 12-minute sessions of KB-HIIT and SIC in a counterbalanced fashion. In the KB-HITT session, 3 circuits of 4 exercises were performed using a Tabata regimen. In the SIC session, three 30-second sprints were performed, with 4 minutes of recovery in between the first 2 sprints and 2.5 minutes of recovery after the last sprint. A within-subjects' design over multiple time points was used to compare oxygen consumption (V[Combining Dot Above]O2), respiratory exchange ratio (RER), tidal volume (TV), breathing frequency (f), minute ventilation (VE), caloric expenditure rate (kcal·min), and heart rate (HR) between the exercise protocols. Additionally, total caloric expenditure was compared. A significant group effect, time effect, and group × time interaction were found for V[Combining Dot Above]O2, RER, and TV, with V[Combining Dot Above]O2 being higher and TV and RER being lower in the KB-HIIT compared with the SIC. Only a significant time effect and group × time interaction were found for f, VE, kcal·min, and HR. Additionally, total caloric expenditure was found to be significantly higher during the KB-HIIT. The results of this study suggest that KB-HIIT may be more attractive and sustainable than SIC and can be effective in stimulating cardiorespiratory and metabolic responses that could improve health and aerobic performance.

  4. Effect of Caffeine Contained in Sports Drink on Hormones Producing Energy Following Sprint Test Performance in Male Soccer Players

    Directory of Open Access Journals (Sweden)

    Mohammad Fayiz Abumoh'd

    2016-05-01

    Full Text Available This study investigated the effect of caffeine contained in sports drink on hormones producing energy and sprint test performance in male soccer players. Twelve participants (25.97 ± 2.70 y performed the test under thre e conditions (one week apart: caffeine with sports drink (SD-CAF, sports drink (SD, and placebo (PLA. Using a double-blind, placebo-controlled, randomized, crossover protocol, participants performed SD-CAF trial (5 mg/kg of caffeine contained in 300 ml of sports drink 30 minutes prior to sprinting test (7 × 30 m, SD trial (solely 300 ml of sports drink 30 minutes prior to sprinting test, or placebo. Blood analysis indicated significantly higher level of free thyroxine in SD-CAF (21.450 ± 3.048 compared to SD (18.742 ± 1.151 and PLA (16.983 ± 1.783. Similar findings existed regarding insulin (P 0.05. No significant differences were observed between trials in first–fourth repetitions (P > 0.05. Time of fifth-seventh repetitions were significantly lower in SD-CAF compared to SD and PLA (P < 0.05, and were significantly lower in SD than that in PLA (P < 0.05. The time of 7th repetition was (4.331 ± 0.210, 4.610 ± 0.197, 4.81 6 ± 0.171 s for SD-CAF, SD, and PLA, respectively; P < 0.05. In conclusion, caffeine interferes hormones that are responsible for producing energy which in turn have a positive effect on repeated sprint bouts.

  5. Acute and Post-Exercise Physiological Responses to High-Intensity Interval Training in Endurance and Sprint Athletes

    Directory of Open Access Journals (Sweden)

    Lukas Cipryan, Gerhard Tschakert, Peter Hofmann

    2017-06-01

    Full Text Available The purpose of the presented study was to compare acute and post-exercise differences in cardiorespiratory, metabolic, cardiac autonomic, inflammatory and muscle damage responses to high-intensity interval exercise (HIIT between endurance and sprint athletes. The study group consisted of sixteen highly-trained males (age 22.1 ± 2.5 years participating in endurance (n = 8 or sprint (n = 8 sporting events. All the participants underwent three exercise sessions: short HIIT (work interval duration 30s, long HIIT (3min and constant load exercise (CE. The exercise interventions were matched for mean power, total time and in case of HIIT interventions also for work-to-relief ratio. The acute cardiorespiratory (HR, V̇O2, RER and metabolic (lactate variables as well as the post-exercise changes (up to 3 h in the heart rate variability, inflammation (interleukin-6, leucocytes and muscle damage (creatine kinase, myoglobin were monitored. Endurance athletes performed exercise interventions with moderately (CE or largely (both HIIT modes higher mean V̇O2. These differences were trivial/small when V̇O2 was expressed as a percentage of V̇O2max. Moderately to largely lower RER and lactate values were found in endurance athletes. Markers of cardiac autonomic regulation, inflammation and muscle damage did not reveal any considerable differences between endurance and sprint athletes. In conclusions, endurance athletes were able to perform both HIIT formats with increased reliance on aerobic metabolic pathways although exercise intensity was identical in relative terms for all the participants. However, other markers of the acute and early post-exercise physiological response to these HIIT interventions indicated similarities between endurance and sprint athletes.

  6. Solar Energy.

    Science.gov (United States)

    Eaton, William W.

    Presented is the utilization of solar radiation as an energy resource principally for the production of electricity. Included are discussions of solar thermal conversion, photovoltic conversion, wind energy, and energy from ocean temperature differences. Future solar energy plans, the role of solar energy in plant and fossil fuel production, and…

  7. Publishing the pamphlet of radiation education for junior high school students

    International Nuclear Information System (INIS)

    Kamezawa, Chika; Kamogawa, Masashi; Kanai, Yuko; Nishiura, Shingo; Banda, Kiyomi; Arakawa, Etsuo

    2014-01-01

    We made supplementary materials of the radiation education as a pamphlet for junior high school students along the government course guidelines for junior high school pressed by Ministry of Education, Culture, Sports, Science and Technology. The pamphlet was published as booklet and calendar. For teachers at junior high schools, a pdf file of the booklet was also appended. The pamphlet focused natural phenomenon and latest researches in the radiation science. Many pictures in the booklet could help students to study the radiation science visually. For 100 days since March 2012 published day, 4119 booklets had been distributed to junior high schools and other schools of applicants, free of charge. (author)

  8. Capturing the Policy that Air Force Raters Use When Writing Performance Appraisals on Junior Officers

    National Research Council Canada - National Science Library

    Stephens, Owen

    2001-01-01

    This study examined the relationship between four dimensions of performance leadership, task performance, interpersonal facilitation, and job dedication and overall performance by junior officers in the Air Force...

  9. Solar energy

    Science.gov (United States)

    Rapp, D.

    1981-01-01

    The book opens with a review of the patterns of energy use and resources in the United States, and an exploration of the potential of solar energy to supply some of this energy in the future. This is followed by background material on solar geometry, solar intensities, flat plate collectors, and economics. Detailed attention is then given to a variety of solar units and systems, including domestic hot water systems, space heating systems, solar-assisted heat pumps, intermediate temperature collectors, space heating/cooling systems, concentrating collectors for high temperatures, storage systems, and solar total energy systems. Finally, rights to solar access are discussed.

  10. Solar Combisystems

    DEFF Research Database (Denmark)

    Thür, Alexander

    2006-01-01

    This note first introduces what is a solar combisystem, the structure how a solar combisystem is build up and what are criteria’s to evaluate a solar combisystem concept. Further on the main components of a solar combisystem, the main characteristics and possible advantages and disadvantages...... compared to each other are described. It is not the goal of this note to explain the technical details how to design all components of a solar combisystem. This is done during other lectures of the solar course and in other basic courses as well. This note tries to explain how a solar combisystem...

  11. An Approach to Energy Education for High School, Junior High School and Elementary School Students at Aichi Institute of Technology

    Science.gov (United States)

    Yukita, Kazuto; Ichiyanagi, Katsuhiro; Mori, Tsuyoshi; Goto, Yasuyuki

    This paper discusses the methods of implementation and improvement adopted in the energy education program of “Marugoto Taiken World” (“Total Experience World”) at Aichi Institute of Technology. The program, which is aimed at high school, junior high school and elementary school students, has been carried on at Aichi Institute of Technology for a number of years now, and the authors have been involved in the energy education project for the past four years. During that time, the following four courses have been held : 1) Let's use wind power to generate electricity, 2) Let's use flowers to build a solar battery, 3) Let's use bottles to build a fuel cell battery, 4) Let's make all sorts of batteries.

  12. Solar Systems

    Science.gov (United States)

    1979-01-01

    The solar collectors shown are elements of domestic solar hot water systems produced by Solar One Ltd., Virginia Beach, Virginia. Design of these systems benefited from technical expertise provided Solar One by NASA's Langley Research Center. The company obtained a NASA technical support package describing the d e sign and operation of solar heating equipment in NASA's Tech House, a demonstration project in which aerospace and commercial building technology are combined in an energy- efficient home. Solar One received further assistance through personal contact with Langley solar experts. The company reports that the technical information provided by NASA influenced Solar One's panel design, its selection of a long-life panel coating which increases solar collection efficiency, and the method adopted for protecting solar collectors from freezing conditions.

  13. Step-to-step spatiotemporal variables and ground reaction forces of intra-individual fastest sprinting in a single session.

    Science.gov (United States)

    Nagahara, Ryu; Mizutani, Mirai; Matsuo, Akifumi; Kanehisa, Hiroaki; Fukunaga, Tetsuo

    2018-06-01

    We aimed to investigate the step-to-step spatiotemporal variables and ground reaction forces during the acceleration phase for characterising intra-individual fastest sprinting within a single session. Step-to-step spatiotemporal variables and ground reaction forces produced by 15 male athletes were measured over a 50-m distance during repeated (three to five) 60-m sprints using a long force platform system. Differences in measured variables between the fastest and slowest trials were examined at each step until the 22nd step using a magnitude-based inferences approach. There were possibly-most likely higher running speed and step frequency (2nd to 22nd steps) and shorter support time (all steps) in the fastest trial than in the slowest trial. Moreover, for the fastest trial there were likely-very likely greater mean propulsive force during the initial four steps and possibly-very likely larger mean net anterior-posterior force until the 17th step. The current results demonstrate that better sprinting performance within a single session is probably achieved by 1) a high step frequency (except the initial step) with short support time at all steps, 2) exerting a greater mean propulsive force during initial acceleration, and 3) producing a greater mean net anterior-posterior force during initial and middle acceleration.

  14. Acute effects of two different initial heart rates on testing the Repeated Sprint Ability in young soccer players.

    Science.gov (United States)

    Ruscello, B; Briotti, G; Tozzo, N; Partipilo, F; Taraborelli, M; Zeppetella, A; Padulo, J; D'Ottavio, S

    2015-10-01

    The aim of this paper was to investigate the acute effects of two different initial heart rates intensities when testing the repeated sprint ability (RSA) performances in young soccer players. Since there are many kinds of pre-match warm-ups, we chose to take as an absolute indicator of internal load the heart rate reached at the end of two different warm-up protocols (60 vs. 90% HRmax) and to compare the respective RSA performances. The RSA tests were performed on fifteen male soccer players (age: 17.9±1.5 years) with two sets of ten shuttle-sprints (15+15 m) with a 1:3 exercise to rest ratio, in different days (randomized order) with different HR% (60 & 90% HRmax). In order to compare the different sprint performances a Fatigue Index (FI%) was computed, while the blood lactate concentrations (BLa-) were measured before and after testing, to compare metabolic demand. Significant differences among trials within each sets (Psoccer player operates during a real match. This background may be partially reproduced by warming up protocols that, by duration and metabolic commitment, can reproduce conveniently the physiological conditions encountered in a real game (e.g. HRmax≈85-95%; BLa->4 mmol/L(-1)).

  15. The relationship between muscle strength, anaerobic performance, agility, sprint ability and vertical jump performance in professional basketball players.

    Science.gov (United States)

    Alemdaroğlu, Utku

    2012-03-01

    The purpose of this study was to investigate the relationship between isokinetic knee strength, anaerobic performance, sprinting ability, agility and vertical jump performance in first division basketball players. Twelve male first division basketball players participated in this study. The mean age was 25.1 ± 1.7 yrs; mean body height 194.8 ± 5.7 cm; mean body mass 92.3± 9.8 kg; mean PBF 10.1± 5.1; and mean VO2max 50.55 ± 6.7 ml/kg/min Quadriceps and hamstrings were measured at 60° and 180°/s, anaerobic performance was evaluated using the Wingate anaerobic power test, sprint ability was determined by single sprint performance (10-30 m), jump performance was evaluated by countermovement (CMJ) and squat jump (SJ) tests and agility performance was measured using the T drill agility test. Quadriceps strength was significantly correlated with peak power at all contraction velocities. However, for mean power, significant correlation was only found between the 60° left and 180° right knee quadriceps measurements. No measure of strength was significantly related to the measurements from/results of field tests. Moreover, strong relations were found between the performance of athletes in different field tests (p< 0.05). The use of correlation analysis is the limitation of the this study.

  16. Relationships between Sprint, Jumping and Strength Abilities, and 800 M Performance in Male Athletes of National and International Levels.

    Science.gov (United States)

    Bachero-Mena, Beatriz; Pareja-Blanco, Fernando; Rodríguez-Rosell, David; Yáñez-García, Juan Manuel; Mora-Custodio, Ricardo; González-Badillo, Juan José

    2017-09-01

    This study analysed the relationships between sprinting, jumping and strength abilities, with regard to 800 m running performance. Fourteen athletes of national and international levels in 800 m (personal best: 1:43-1:58 min:ss) completed sprint tests (20 m and 200 m), a countermovement jump, jump squat and full squat test as well as an 800 m race. Significant relationships (p relationship between the first to the last 50 m interval times and the 800 m time tended to increase (1st 50 m: r = 0.71; 2nd 50 m: r = 0.72; 3rd 50 m: r = 0.81; 4th 50 m: r = 0.85). Performance in 800 m also correlated significantly (p < 0.01-0.05) with strength variables: the countermovement jump (r = -0.69), jump squat (r = -0.65), and full squat test (r = -0.58). Performance of 800 m in high-level athletes was related to sprint, strength and jumping abilities, with 200 m and the latest 50 m of the 200 m being the variables that most explained the variance of the 800 m performance.

  17. Solar radiophysics

    International Nuclear Information System (INIS)

    McLean, D.J.; Labrum, N.R.

    1985-01-01

    This book treats all aspects of solar radioastronomy at metre wavelengths, particularly work carried out on the Australian radioheliograph at Culgoora, with which most of the authors have been associated in one way or another. After an introductory section on historical aspects, the solar atmosphere, solar flares, and coronal radio emission, the book deals with instrumentation, theory, and details of observations and interpretations of the various aspects of metrewave solar radioastronomy, including burst types, solar storms, and the quiet sun. (U.K.)

  18. JS3P: junior staff programme pilot project

    International Nuclear Information System (INIS)

    Pretrel, H.; Tregoures, N.; Bessiron, V.; Dehoyos, A.; Delvallee, I.; Brisson, N.; Debayle, C.; Dubreuil, M.; Nicaise, G.; Perignon, J.P.; Richard, J.; Reinke, N.; Kaulard, J.; Burgener, M.; Keesmann, S.; Schramm, B.; Seubert, A.; Sternkopf, J.; Thuma, G.; Weber, S.; Smidts, O.; Maillet, E.; Bucalossi, A.; Van haesendonck, M.; Uyttenhove, W.; Mertens, J.

    2006-01-01

    Concept: The objective of the project is to allow junior staff members from the European Technical Safety Organisations (TSOs), IRSN, GRS and AVN, to work together with the final goal of creating a junior staff network, based on technical, cultural and personal interests. These projects are to show junior staff members at a very early stage during their career the need for European collaborations. They are also a tool to explore new subjects of co-operation. It is an initiative that should strengthen the links between the organisations and contribute to establishing the future of nuclear safety in Europe. A JS3P (Junior Staff Programme Pilot Project) is a project done jointly by 'junior' staff members from the three TSOs, where experience of 'seniors' is also integrated when needed. Compared to other collaborative activities, it has certain specific features. The JS3P favours staff exchanges, and technical meetings of several days should be planned during a project in order to encourage people to work together. Technical objectives are shared and the work is done jointly (reports, articles). The team involved in the JS3P should be as small as possible to favour its efficiency. The JS3P is short and easy to realize. Its duration is fixed to a maximum of about 12 months with the option to be prolonged. Typical topics are bibliographic work, comparison issues, scientific surveys, benchmark exercises and prospective investigations on innovative ideas. They can be linked to existing joint projects and then form a smaller module integrated into the large project. Topics may concern prospective issues, tentatively investigating new topics that can be seen as exploratory co-operation projects. Subjects may also concern research issues that are not a priority but that deserve to be investigated as new attractive topics. The JS3P is defined and managed by junior staff members. It is approved by a management board committee and supervised by a technical steering committee

  19. Similar inflammatory responses following sprint interval training performed in hypoxia and normoxia

    Directory of Open Access Journals (Sweden)

    Alan James Richardson

    2016-08-01

    Full Text Available Sprint interval training (SIT is an efficient intervention capable of improving aerobic capacity and exercise performance. This experiment aimed to determine differences in training adaptations and the inflammatory responses following 2 weeks of SIT (30s maximal work, 4 min recovery; 4-7 repetitions performed in normoxia or hypoxia. Forty-two untrained participants [(mean ± SD, age 21 ±1 yrs, body mass 72.1 ±11.4 kg and height 173 ±10 cm] were equally and randomly assigned to one of three groups; control (CONT; no training, n = 14, normoxic (NORM; SIT in FiO2: 0.21, n = 14 and normobaric hypoxic (HYP; SIT in FiO2: 0.15, n = 14. Participants completed a V̇O2peak test, a time to exhaustion (TTE trial (power = 80% V̇O2peak and had haematological [haemoglobin (Hb, haematocrit (Hct] and inflammatory markers [interleukin-6 (IL-6, tumor necrosis factor-α (TNFα] measured in a resting state, pre and post SIT. V̇O2peak (mL.kg-1.min-1 improved in HYP (+11.9% and NORM (+9.8%, but not CON (+0.9%. Similarly TTE improved in HYP (+32.2% and NORM (+33.0%, but not CON (+3.4% whilst the power at the anaerobic threshold (AT; W.kg-1 also improved in HYP (+13.3% and NORM (+8.0%, but not CON (-0.3%. AT (mL.kg-1.min-1 improved in HYP (+9.5%, but not NORM (+5% or CON (-0.3%. No between group change occurred in 30 s sprint performance or Hb and Hct. IL-6 increased in HYP (+17.4% and NORM (+20.1%, but not CON (+1.2% respectively. TNF-α increased in HYP (+10.8% NORM (+12.9% and CON (+3.4%.SIT in HYP and NORM increased VO2peak, power at AT and TTE performance in untrained individuals, improvements in AT occurred only when SIT was performed in HYP. Increases in IL-6 and TNFα reflect a training induced inflammatory response to SIT; hypoxic conditions do not exacerbate this.

  20. Community-driven development for computational biology at Sprints, Hackathons and Codefests.

    Science.gov (United States)

    Möller, Steffen; Afgan, Enis; Banck, Michael; Bonnal, Raoul J P; Booth, Timothy; Chilton, John; Cock, Peter J A; Gumbel, Markus; Harris, Nomi; Holland, Richard; Kalaš, Matúš; Kaján, László; Kibukawa, Eri; Powel, David R; Prins, Pjotr; Quinn, Jacqueline; Sallou, Olivier; Strozzi, Francesco; Seemann, Torsten; Sloggett, Clare; Soiland-Reyes, Stian; Spooner, William; Steinbiss, Sascha; Tille, Andreas; Travis, Anthony J; Guimera, Roman; Katayama, Toshiaki; Chapman, Brad A

    2014-01-01

    Computational biology comprises a wide range of technologies and approaches. Multiple technologies can be combined to create more powerful workflows if the individuals contributing the data or providing tools for its interpretation can find mutual understanding and consensus. Much conversation and joint investigation are required in order to identify and implement the best approaches. Traditionally, scientific conferences feature talks presenting novel technologies or insights, followed up by informal discussions during coffee breaks. In multi-institution collaborations, in order to reach agreement on implementation details or to transfer deeper insights in a technology and practical skills, a representative of one group typically visits the other. However, this does not scale well when the number of technologies or research groups is large. Conferences have responded to this issue by introducing Birds-of-a-Feather (BoF) sessions, which offer an opportunity for individuals with common interests to intensify their interaction. However, parallel BoF sessions often make it hard for participants to join multiple BoFs and find common ground between the different technologies, and BoFs are generally too short to allow time for participants to program together. This report summarises our experience with computational biology Codefests, Hackathons and Sprints, which are interactive developer meetings. They are structured to reduce the limitations of traditional scientific meetings described above by strengthening the interaction among peers and letting the participants determine the schedule and topics. These meetings are commonly run as loosely scheduled "unconferences" (self-organized identification of participants and topics for meetings) over at least two days, with early introductory talks to welcome and organize contributors, followed by intensive collaborative coding sessions. We summarise some prominent achievements of those meetings and describe differences in how

  1. Butterfly Sprint Swimming Technique, Analysis of Somatic and Spatial-Temporal Coordination Variables

    Directory of Open Access Journals (Sweden)

    Strzała Marek

    2017-12-01

    Full Text Available The aim of this study was to investigate somatic properties and force production of leg extensor muscles measured in the countermovement jump test (CMJ, as well as to analyse kinematic variables of sprint surface butterfly swimming. Thirty-four male competitive swimmers were recruited with an average age of 19.3 ± 1.83 years. Their average body height (BH was 183.7 ± 5.93 cm, body fat content 10.8 ± 2.64% and body mass (BM 78.3 ± 5.0 kg. Length measurements of particular body segments were taken and a counter movement jump (CMJ as well as an all-out 50 m butterfly speed test were completed. The underwater movements of the swimmers’ bodies were recorded with a digital camera providing side-shots. We registered a significant relationship between body mass (r = 0.46, lean body mass (r = 0.48 and sprint surface butterfly swimming (VSBF. The anaerobic power measured in the CMJ test, total body length (TBL as well as upper and lower extremity length indices did not influence swimming speed significantly. The temporal entry-kick index (the time ratio between the first kick and arm entry significantly influenced VSBF (r = -0.45. Similarly, medium power of the coefficient was indicated between a stroke rate kinematics (SR, b duration of the first leg kick (LP1, c air phase duration of arm recovery (Fly-arm, and VSBF (r = 0.40; r = 0.40 and r = 0.41, respectively. The entry-kick temporal index showed that, in the butterfly cycle, an appropriately early executed initial kick when compared to arm entry was associated with a longer arm propulsion phase, which in turn was associated with minimizing resistive gliding phases and enabled relatively longer and less resistive air arm recovery (higher value of the fly-arm index. The higher value of SR kinematic was another important element of the best butterfly results in this study.

  2. [Stress at work and well-being in junior residents].

    Science.gov (United States)

    Buddeberg-Fischer, Barbara; Klaghofer, Richard; Buddeberg, Claus

    2005-01-01

    The present study investigated the workplace experiences of junior physicians in their first year of residency, and the impact of these experiences on their physical and psychological well-being. In a prospective longitudinal study 518 junior physicians (54.4% women, 45.6% men) were investigated twice within two years with regard to individual and institutional determinants of career development. Gender-relevant workplace experiences, i. e. effort-reward imbalance, and their relation to physical and psychological well-being, i. e. anxiety and depression, as well as life satisfaction were evaluated. The workplace experiences revealed three significant gender-specific results: Women residents received less mentoring, had more positive social relationships at work, and showed a higher over-commitment than their male colleagues. Both men and women residents reported significantly worse physical and psychological well-being as well as life satisfaction after their first year of residency (T2) compared to the time directly before their graduation from medical school (T1). The junior physicians' life satisfaction scores are significantly lower than those of the normal population. 7-10% of the respondents showed anxiety scores above cut-off, and 1-4% depression scores above cut-off. Personality traits such as a high sense of coherence and low expressiveness are protective factors for well-being and life satisfaction. Insufficient leadership of senior residents and unclear hierarchical structures as well as stress at work and over-commitment are risk factors for the development of symptoms of anxiety and/or depression. The reported results are consistent with the psychosocial stress model by Karasek and Theorell as well as with the model of effort-reward imbalance of Siegrist.

  3. [The comprehensive approach to the rehabilitative treatment of junior athletes].

    Science.gov (United States)

    Stepanenko, N P; Levitskaya, T E; Tsekhmeistruk, E A; Tren'kaeva, N A; Tyulyupo, S V; Dostovalova, O V; Kremeno, S V; Shakhova, S S; Chekcheeva, V D

    The objective of the present study was the development of the comprehensive program for the medico-psychological follow-up of the male and female junior athletes (rhythmic gymnastics) with the purpose of stabilizing their hormonal and emotional status, as well as improving sport performances based on the use of modern hardware-software technologies. The comprehensive examination of 72 female athletes at the mean age of 11.5±0.6 years attending R. Kuznetsov specialized school of rhythmic gymnastics of the Olympic reserve in the city of Seversk has been undertaken on the basis of Tomsk Research Institute of Balneology and Physiotherapy, the branch of Siberian Federal Research and Clinical Centre. The program of comprehensive medical psychological rehabilitation for the junior athletes of either sex engaged in sportive activities requiring precise technical actions has been elaborated. The method of the combined therapeutic treatment included physical exercises therapy, manual massage, dry carbonic bathtubs, psychological activities with the application of biological feedback trainings and cognitive trainings; it was intended for the correction of the hormonal status and the improvement of the psycho-emotional conditions of the athletes. The combined treatment based on the use of the modern hardware-software technologies was shown to promote the restoration and development of the psychophysical and psychological qualities of the male and female junior athletes indispensable for the maintenance of their high readiness for the efficient sports activities at the subsequent stages of the training cycle. In addition, such treatment enhances the adaptation resources of the athletes.

  4. Academic achievement of junior high school students with sleep disorders

    Directory of Open Access Journals (Sweden)

    Fijri Auliyanti

    2015-03-01

    Full Text Available Background Sleep disorders are prevalent in adolescents and may influence their academic achievement. To date, no study has been done in Indonesia on academic achievement in students with sleep disorders and its related factors. Objective To assess for relationships between academic achievement and related factors, including gender, motivation and learning strategies, IQ level, maternal educational level, socioeconomic status, family structure, after-hours education program, presence of TV/computer in the bedroom, sleep duration during school days, as well as bedtime and wakeup time difference in junior high school students with sleep disorders. Methods This cross-sectional study was performed from January to March 2013. Subjects were students from five junior high schools in Jakarta who fulfilled the criteria for sleep disorders based on the Sleep Disturbance Scale for Children questionnaire. Results There were 111 study subjects. The prevalence of sleep disorders was 39.7%, mostly in difficulties initiating and maintaining sleep (70.2%. Below-average academic achievement was seen in 47.6% of subjects. Factors significantly related to below-average academic achievement were after-hours education program (prevalence ratio 5.6; 95%CI 1.36 to 23.18; P = 0.017, average IQ level (prevalence ratio 3.26; 95%CI 1.38 to 7.71; P = 0.007, and male gender (prevalence ratio 2.68; 95%CI 1.06 to 6.78; P = 0.037. Conclusion Among junior high school students with sleep disorders, factors related to below-average academic achievement are afterhours education program (more than 2 types, the average IQ level, and male gender.

  5. Bollasina Receives 2013 James R. Holton Junior Scientist Award: Response

    Science.gov (United States)

    Bollasina, Massimo A.

    2014-08-01

    I am deeply honored to have been selected as this year's recipient of the James R. Holton Junior Scientist Award, and I receive it with heartfelt gratitude and humility. I clearly remember Peter Webster's call announcing the amazing news and how I literally remained speechless and overwhelmed. I would like to express my sincere appreciation to the Atmospheric Sciences section of AGU and the members of the award committee. I am even more appreciative to have been presented this award handed by two outstanding scientists—Peter Webster and Bill Lau—who have remarkably contributed to our understanding of the Asian monsoon and tropical climate, my area of expertise.

  6. A Multifaceted Mentoring Program for Junior Faculty in Academic Pediatrics.

    Science.gov (United States)

    Chen, Mary M; Sandborg, Christy I; Hudgins, Louanne; Sanford, Rania; Bachrach, Laura K

    2016-01-01

    The departure of physician-scientists from education and research into clinical practice is a growing challenge for the future of academic medicine. Junior faculty face competing demands for clinical productivity, teaching, research, and work-life integration, which can undermine confidence in the value of an academic career. Mentorship is important to foster career development and satisfaction in junior faculty. The goals of this academic pediatrics department were to develop, implement, and evaluate a multifaceted pediatric mentoring program to promote retention and satisfaction of junior faculty. Program elements included one-on-one mentor-mentee meetings, didactic workshops, grant review assistance, and facilitated peer-group mentoring. Program effectiveness was assessed using annual surveys of mentees and structured mentee exit interviews, as well as retention data for assistant professors. The mentees were instructors and assistant professors in the department of pediatrics. Seventy-nine mentees participated in the program from 2007 through 2014. The response rate from seven annual surveys was 84%. Sixty-nine percent of mentees felt more prepared to advance their careers, 81% had a better understanding of the criteria for advancement, 84% were satisfied with the program, and 95% found mentors accessible. Mentees who exited the program reported they most valued the one-on-one mentoring and viewed the experience positively regardless of promotion. Retention of assistant professors improved after initiation of the program; four of 13 hired from 2002 to 2006 left the institution, whereas 18 of 18 hired from 2007 to 2014 were retained. This multifaceted mentoring program appeared to bolster satisfaction and enhance retention of junior pediatric faculty. Mentees reported increased understanding of the criteria for promotion and viewed the program as a positive experience regardless of career path. Individual mentor-mentee meetings were needed at least twice yearly

  7. The educational value of ward rounds for junior trainees

    Directory of Open Access Journals (Sweden)

    Faidon-Marios Laskaratos

    2015-04-01

    Full Text Available The ward round (WR is a complex task and medical teachers are often faced with the challenge of finding a balance between service provision and clinical development of learners. The educational value of WRs is an under-researched area. This short communication aims to evaluate the educational role of WRs for junior trainees and provides insight into current practices. It also identifies obstacles to effective teaching/training in this setting and provides suggestions for improving the quality of WR teaching.

  8. CAREER TRANSITION FROM JUNIOR TO SENIOR IN BASKETBALL PLAYERS

    Directory of Open Access Journals (Sweden)

    Alberto Lorenzo

    2009-01-01

    Full Text Available The purpose of the study was to investigate what factors affect basketball players in the transition from junior and amateur to senior and professional sport respectively. The study was a qualitative research which uses a semi-structured interview to get the data. There were interviewed five Spanish basketball players who were starting playing in a team of Basketball Club Association (C.B.A.. The results showed that the participants face several changes both in the sport and in the life outside sport. At the same time, the results indicated the existence of several coping strategies that help the player in his career transition.

  9. Is international junior success a reliable predictor for international senior success in elite combat sports?

    Science.gov (United States)

    Li, Pingwei; De Bosscher, Veerle; Pion, Johan; Weissensteiner, Juanita R; Vertonghen, Jikkemien

    2018-05-01

    Currently in the literature, there is a dearth of empirical research that confirms whether international junior success is a reliable predictor for future international senior success. Despite the uncertainty of the junior-senior relationship, federations and coaches still tend to use junior success as a predictor for long-term senior success. A range of former investigations utilising a retrospective lens has merely focused on success that athletes attained at junior level competitions. Success that was achieved at senior-level competitions but at a junior age was relatively ignored. This study explored to what extent international senior success can be predicted based on success that athletes achieved in either international junior level competitions (i.e. junior medalists) or senior competitions at a junior age (i.e. early achievers). The sample contains 4011 international male and female athletes from three combat sports (taekwondo, wrestling and boxing), who were born between 1974 and 1990 and participated in both international junior and senior-level competitions between 1990 and 2016. Gender and sport differences were compared. The results revealed that 61.4% of the junior medalists and 90.4% of the early achievers went on to win international medals at a senior age. Among the early achievers, 92.2% of the taekwondo athletes, 68.4% of the wrestling athletes and 37.9% of the boxing athletes could be reliably "predicted" to win international senior medals. The findings demonstrate that specific to the three combat sports examined, international junior success appears to be an important predictor to long-term international senior success.

  10. Validity and reliability of GPS and LPS for measuring distances covered and sprint mechanical properties in team sports.

    Science.gov (United States)

    Hoppe, Matthias W; Baumgart, Christian; Polglaze, Ted; Freiwald, Jürgen

    2018-01-01

    This study aimed to investigate the validity and reliability of global (GPS) and local (LPS) positioning systems for measuring distances covered and sprint mechanical properties in team sports. Here, we evaluated two recently released 18 Hz GPS and 20 Hz LPS technologies together with one established 10 Hz GPS technology. Six male athletes (age: 27±2 years; VO2max: 48.8±4.7 ml/min/kg) performed outdoors on 10 trials of a team sport-specific circuit that was equipped with double-light timing gates. The circuit included various walking, jogging, and sprinting sections that were performed either in straight-lines or with changes of direction. During the circuit, athletes wore two devices of each positioning system. From the reported and filtered velocity data, the distances covered and sprint mechanical properties (i.e., the theoretical maximal horizontal velocity, force, and power output) were computed. The sprint mechanical properties were modeled via an inverse dynamic approach applied to the center of mass. The validity was determined by comparing the measured and criterion data via the typical error of estimate (TEE), whereas the reliability was examined by comparing the two devices of each technology (i.e., the between-device reliability) via the coefficient of variation (CV). Outliers due to measurement errors were statistically identified and excluded from validity and reliability analyses. The 18 Hz GPS showed better validity and reliability for determining the distances covered (TEE: 1.6-8.0%; CV: 1.1-5.1%) and sprint mechanical properties (TEE: 4.5-14.3%; CV: 3.1-7.5%) than the 10 Hz GPS (TEE: 3.0-12.9%; CV: 2.5-13.0% and TEE: 4.1-23.1%; CV: 3.3-20.0%). However, the 20 Hz LPS demonstrated superior validity and reliability overall (TEE: 1.0-6.0%; CV: 0.7-5.0% and TEE: 2.1-9.2%; CV: 1.6-7.3%). For the 10 Hz GPS, 18 Hz GPS, and 20 Hz LPS, the relative loss of data sets due to measurement errors was 10.0%, 20.0%, and 15.8%, respectively. This study shows that

  11. Performance and Metabolic Demand of a New Repeated-Sprint Ability Test in Basketball Players: Does the Number of Changes of Direction Matter?

    Science.gov (United States)

    Zagatto, Alessandro M; Ardigò, Luca P; Barbieri, Fabio A; Milioni, Fabio; Dello Iacono, Antonio; Camargo, Bruno H F; Padulo, Johnny

    2017-09-01

    Zagatto, AM, Ardigò, LP, Barbieri, FA, Milioni, F, Dello Iacono, A, Camargo, BHF, and Padulo, J. Performance and metabolic demand of a new repeated-sprint ability test in basketball players: does the number of changes of direction matter? J Strength Cond Res 31(9): 2438-2446, 2017-This study compared 2 repeated-sprint ability (RSA) tests in basketball players. Both tests included 10 × 30-m sprints, with the difference that the previously validated test (RSA2COD) featured 2 changes of direction (COD) per sprint, whereas the experimental test (RSA5COD) featured 5 CODs per sprint. Test performances and metabolic demands were specifically assessed in 20 basketball players. First, RSA5COD test-retest reliability was investigated. Then, RSA2COD, RSA5COD sprint times, peak speeds, oxygen uptake (V[Combining Dot Above]O2) and posttest blood lactate concentration [La] were measured. The RSA5COD results showed to be reliable. RSA2COD performance resulted better than the RSA5COD version (p 0.05). Over whole bout, the RSA2COD was more demanding than the RSA5COD, considering overall metabolic power requirement (i.e., VO2-driven + [La]-driven components). Given that RSA5COD (a) mimics real game-play as sprint distance and action change frequency/direction and (b) has the same metabolic expenditure per task completion as metabolic cost, RSA5COD is a valuable option for players and coaches for training basketball-specific agility and assessing bioenergetic demands.

  12. Sprinting, Change of Direction Ability and Horizontal Jump Performance in Youth Runners According to Gender

    Directory of Open Access Journals (Sweden)

    Yanci Javier

    2017-12-01

    Full Text Available The purpose of the study was to assess straight sprinting, change of direction ability and horizontal jump performance in youth runners according to age and gender. Two hundred and fifty-five youth runners (116 boys and 139 girls participated in this study. The athletes were divided according to their age into five groups: under 8 yr (U8, under 10 yr (U10, under 12 yr (U12, under 14 yr (U14 and under 16 yr (U16. Significant differences (p 0.05, d = 0.29-1.17 between U14 and U16 were observed in any of the tests. With regard to age and gender, in U8 and U10 groups there were no significant differences (p > 0.05, d = 0.02-0.76 between boys and girls in any test. However, in U12 and U14 groups, significant gender differences (p < 0.05, d = 0.85-1.24 were found in the MAT. Likewise, the boys obtained better results than girls in the horizontal jump tests (p < 0.05, d = 1.01-1.26. After the classification by age, some differences were observed between both genders, depending on the fitness variable evaluated.

  13. The physiological stress response to high-intensity sprint exercise following the ingestion of sodium bicarbonate.

    Science.gov (United States)

    Peart, Daniel J; Kirk, Richard J; Hillman, Angela R; Madden, Leigh A; Siegler, Jason C; Vince, Rebecca V

    2013-01-01

    The purpose of this study was to investigate the effects of pre-exercise alkalosis on the physiological stress response to high-intensity exercise. Seven physically active males (age 22 ± 3 years, height 1.82 ± 0.06 m, mass 81.3 ± 8.4 kg and peak power output 300 ± 22 W) performed a repeated sprint cycle exercise following a dose of 0.3 g kg(-1) body mass of sodium bicarbonate (NaHCO(3)) (BICARB), or a placebo of 0.045 g kg(-1) body mass of sodium chloride (PLAC). Monocyte-expressed heat shock protein 72 (HSP72) and plasma thiobarbituric acid reactive substances (TBARS) were significantly attenuated in BICARB compared to PLAC (p = 0.04 and p = 0.039, respectively), however total anti-oxidant capacity, the ratio of oxidised to total glutathione, cortisol, interleukin 6 and interleukin 8 were not significantly induced by the exercise. In conclusion, monocyte-expressed HSP72 is significantly increased following high-intensity anaerobic exercise, and its attenuation following such exercise with the ingestion of NaHCO(3) is unlikely to be due to a decreased oxidative stress.

  14. Effect of sprint training: training once daily versus twice every second day.

    Science.gov (United States)

    Ijichi, Toshiaki; Hasegawa, Yuta; Morishima, Takuma; Kurihara, Toshiyuki; Hamaoka, Takafumi; Goto, Kazushige

    2015-01-01

    This study compared training adaptations between once daily (SINGLE) and twice every second day (REPEATED) sprint training, with same number of training sessions. Twenty physically active males (20.9 ± 1.3 yr) were assigned randomly to the SINGLE (n = 10) or REPEATED (n = 10) group. The SINGLE group trained once per day (5 days per week) for 4 weeks (20 sessions in total). The REPEATED group conducted two consecutive training sessions on the same day, separated by a rest period of 1 h (2-3 days per week) for 4 weeks (20 sessions in total). Each training session consisted of three consecutive 30-s maximal pedalling sets with a 10-min rest between sets. Before and after the training period, the power output during two bouts of 30-s maximal pedalling, exercise duration during submaximal pedalling and resting muscle phosphocreatine (PCr) levels were evaluated. Both groups showed significant increases in peak and mean power output during the two 30-s bouts of maximal pedalling after the training period (P every second day improved OBLA during endurance exercise more than the same training once daily.

  15. Relation between Peak Power Output in Sprint Cycling and Maximum Voluntary Isometric Torque Production.

    Science.gov (United States)

    Kordi, Mehdi; Goodall, Stuart; Barratt, Paul; Rowley, Nicola; Leeder, Jonathan; Howatson, Glyn

    2017-08-01

    From a cycling paradigm, little has been done to understand the relationships between maximal isometric strength of different single joint lower body muscle groups and their relation with, and ability to predict PPO and how they compare to an isometric cycling specific task. The aim of this study was to establish relationships between maximal voluntary torque production from isometric single-joint and cycling specific tasks and assess their ability to predict PPO. Twenty male trained cyclists participated in this study. Peak torque was measured by performing maximum voluntary contractions (MVC) of knee extensors, knee flexors, dorsi flexors and hip extensors whilst instrumented cranks measured isometric peak torque from MVC when participants were in their cycling specific position (ISOCYC). A stepwise regression showed that peak torque of the knee extensors was the only significant predictor of PPO when using SJD and accounted for 47% of the variance. However, when compared to ISOCYC, the only significant predictor of PPO was ISOCYC, which accounted for 77% of the variance. This suggests that peak torque of the knee extensors was the best single-joint predictor of PPO in sprint cycling. Furthermore, a stronger prediction can be made from a task specific isometric task. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. The effects of acute creatine supplementation on multiple sprint cycling and running performance in rugby players.

    Science.gov (United States)

    Ahmun, Robert P; Tong, Richard J; Grimshaw, Paul N

    2005-02-01

    The benefits of creatine (CR) supplementation are well documented, particularly during repeated bouts of high-intensity muscular activity. Most published experiments use mass-supported (cycle ergometry) activities as a means of evaluating creatine's efficacy, therefore minimizing any possible adverse effects of increased body mass associated with CR supplementation. This study aims to use both mass-supported and mass-dependent activities to assess the effectiveness of acute CR supplementation on a group of highly trained rugby players. A randomized, double-blind, crossover research design was utilized, with subjects receiving 20 g.d(-1) x 5 d of both CR and a glucose placebo (PL). Subjects were assessed via 10 x 6-second Wingate test and a 10 x 40-m sprint test on separate days, presupplementation and postsupplementation. A 28-d washout period separated the two treatments. No significant treatment (p > 0.05) or treatment by test interaction effects (p > 0.05) were observed for peak or minimum power output (W), peak or minimum running velocity (m.s(-1)), or fatigue index (%). No significant differences (p > 0.05) were found postsupplementation for body mass and percentage body fat. Although statistical significance was not achieved for any of the measured parameters, there were small improvements in performance that may be of benefit to rugby players.

  17. Effect of increasing energy cost on arm coordination in elite sprint swimmers.

    Science.gov (United States)

    Komar, J; Leprêtre, P M; Alberty, M; Vantorre, J; Fernandes, R J; Hellard, P; Chollet, D; Seifert, L

    2012-06-01

    The purpose of this study was to analyze the changes in stroke parameters, motor organization and swimming efficiency with increasing energy cost in aquatic locomotion. Seven elite sprint swimmers performed a 6×300-m incremental swimming test. Stroke parameters (speed, stroke rate and stroke length), motor organization (arm stroke phases and arm coordination index), swimming efficiency (swimming speed squared and hand speed squared) and stroke index were calculated from aerial and underwater side-view cameras. The energy cost of locomotion was assessed by measuring oxygen consumption and blood lactate. Results showed that the increase in energy cost of locomotion was correlated to an increase in the index of coordination and stroke rate, and a decrease in stroke length (pstroke index did not change significantly with the speed increments (pstroke rate were observed, along with a decrease in stroke length, stroke index and hand speed squared with each increment, revealing an adaptation to the fatigue within the 300m. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. Inter-limb coordination, strength, jump, and sprint performances following a youth men's basketball game.

    Science.gov (United States)

    Cortis, Cristina; Tessitore, Antonio; Lupo, Corrado; Pesce, Caterina; Fossile, Eugenio; Figura, Francesco; Capranica, Laura

    2011-01-01

    This study aimed to verify whether basketball players are able to maintain strength (handgrip), jump (countermovement jump [CMJ]), sprint (10 m and 10 m bouncing the ball [10 mBB]), and interlimb coordination (i.e., synchronized hand and foot flexions and extensions at 80, 120, and 180 bpm) performances at the end of their game. Ten young (age 15.7 ± 0.2 years) male basketball players volunteered for this study. During the friendly game, heart rate (HR), rate of perceived exertion (RPE), and rate of muscle pain (RMP) were assessed to evaluate the exercise intensity. Overall, players spent 80% of the time playing at intensities higher than 85% HRmax. Main effects (p jump (pre = 35.2 ± 5.2 cm, post = 35.7 ± 5.2 cm), handgrip (pre = 437 ± 73 N, post = 427 ± 55 N), and coordinative performances at lower frequencies of executions (80 bpm: pre = 59.7 ± 1.3 seconds, post = 60.0 ± 0.0 seconds; 120 bpm: pre = 54.7 ± 12.3 seconds, post = 57.3 ± 6.7 seconds). These findings indicate that the heavy load of the game exerts beneficial effects on the efficiency of executive and attentive control functions involved in complex motor behaviors. Coaches should structure training sessions that couple intense physical exercises with complex coordination tasks to improve the attentional capabilities of the players.

  19. Does decision documentation help junior designers rationalize their decisions? A comparative multiple-case study

    NARCIS (Netherlands)

    Heesch, U. van; Avgeriou, P.; Tang, A.

    Software architecture design is challenging, especially for junior software designers. Lacking practice and experience, junior designers need process support in order to make rational architecture decisions. In this paper, we present the results of a comparative multiple-case study conducted to find

  20. A Longitudinal Study of Physical Fitness in Elite Junior Tennis Players

    NARCIS (Netherlands)

    Kramer, Tamara; Huijgen, Barbara C. H.; Elferink-Gemser, Marije T.; Visscher, Chris

    Purpose: To analyze how physical fitness (PF) improves in elite junior tennis players related to age, maturity, and performance level. Methods: Elite junior tennis players (n = 113 boys, n = 83 girls) divided by performance level were monitored longitudinally from U14 to U16. Maturity, upper and

  1. First aid and basic life support of junior doctors: A prospective study in Nijmegen, the Netherlands.

    NARCIS (Netherlands)

    Tan, E.C.T.H.; Severien, I.; Metz, J.C.; Berden, H.J.J.M.; Biert, J.

    2006-01-01

    According to the Dutch medical education guidelines junior doctors are expected to be able to perform first aid and basic life support. A prospective study was undertaken to assess the level of first aid and basic life support (BLS) competence of junior doctors at the Radboud University Nijmegen

  2. Examination of Turkish Junior High-School Students' Perceptions of the General Problem-Solving Process

    Science.gov (United States)

    Ekici, Didem Inel

    2016-01-01

    This study aimed to determine Turkish junior high-school students' perceptions of the general problem-solving process. The Turkish junior high-school students' perceptions of the general problem-solving process were examined in relation to their gender, grade level, age and their grade point with regards to the science course identified in the…

  3. Collaboration with Sport Psychologists as Viewed by Female Volleyball Junior Teams

    Science.gov (United States)

    Otrebski, Wojciech; Rutkowska, Katarzyna

    2008-01-01

    Study aim: To determine the need of female junior volleyball players to collaborate with a psychologist, considering previous sport career of those players. Material and methods: A group of 78 female volleyball players aged 14-17 years from 7 top Polish junior teams participated in the study. They were requested to fill questionnaires on their…

  4. Emotional Labour, Training Stress, Burnout, and Depressive Symptoms in Junior Doctors

    Science.gov (United States)

    Rogers, Mary E.; Creed, Peter A.; Searle, Judy

    2014-01-01

    Junior doctors are at risk of work-related burnout and mental health problems due to training workload demands and responsibilities. This study investigated the predictors of work-related burnout and depressive symptoms in junior doctors. Participants were 349 Australian doctors in postgraduate years 1-4, who completed a web-based survey assessing…

  5. Improving Junior High School Students' Mathematical Analogical Ability Using Discovery Learning Method

    Science.gov (United States)

    Maarif, Samsul

    2016-01-01

    The aim of this study was to identify the influence of discovery learning method towards the mathematical analogical ability of junior high school's students. This is a research using factorial design 2x2 with ANOVA-Two ways. The population of this research included the entire students of SMPN 13 Jakarta (State Junior High School 13 of Jakarta)…

  6. English Cooperative Learning Mode in a Rural Junior High School in China

    Science.gov (United States)

    Zhang, Haiyan; Peng, Wen; Sun, Liuhua

    2017-01-01

    Cooperative learning is one of the most recognized and fruitful research areas in modern education practice. It has been widely used in many countries as an effective teaching strategy to improve class efficiency and students' comprehensive language ability since the 1990's. This paper takes JA Junior High School, a rural junior high school in…

  7. Adolescent Views of Time Management: Rethinking the School Day in Junior High School

    Science.gov (United States)

    Strom, Paris S.; Strom, Robert D.; Sindel-Arrington, Tricia

    2016-01-01

    Junior high school presents a significant increase in time demands both for study and for social relationships. The students (N = 240) in grades 7 and 8 at a junior high school anonymously completed online the Time Management Poll concerning their own use of time and the way their school managed time. The 20 items in the poll allowed them to…

  8. An Assessment of Campus Police Departments across Mississippi's Public Community and Junior Colleges

    Science.gov (United States)

    Boggs, Brad D.

    2012-01-01

    The purpose of the study was to provide an assessment of campus police departments throughout the 15 public community and junior colleges in Mississippi. This research could provide Mississippi community and junior college administrators the opportunity to observe and appraise the overall safety of their respective campuses in comparison to safety…

  9. 75 FR 36659 - Proposed Collection; Comment Request; Brain Power! The NIDA Junior Scientist Program and the...

    Science.gov (United States)

    2010-06-28

    ... of the Brain Power! Program's ability to: Increase students' knowledge about the biology of the brain... Request; Brain Power! The NIDA Junior Scientist Program and the Companion Program, Brain Power! Challenge.... Proposed Collection: Title: Brain Power! The NIDA Junior Scientist Program, for grades K-5, and the...

  10. Traditional-Aged College Juniors' Career Planning Self-Efficacy: A Case Study

    Science.gov (United States)

    Sherman, Dawn C.

    2012-01-01

    The purpose of this single-site case study was to explore and describe traditional-age college juniors' reports of self-efficacy (Bandura, 1997) regarding Career Planning (Barker & Kellen, 1998). More specifically, the career planning confidence levels of college juniors enrolled in a required career development course at a private business…

  11. Card Games and Algebra Tic Tacmatics on Achievement of Junior Secondary II Students in Algebraic Expressions

    Science.gov (United States)

    Okpube, Nnaemeka Michael; Anugwo, M. N.

    2016-01-01

    This study investigated the Card Games and Algebra tic-Tacmatics on Junior Secondary II Students' Achievement in Algebraic Expressions. Three research questions and three null hypotheses guided the study. The study adopted the pre-test, post-test control group design. A total of two hundred and forty (240) Junior Secondary School II students were…

  12. Effects of Music on Physical Activity Rates of Junior High School Physical Education Students

    Science.gov (United States)

    Brewer, Lindsey; Barney, David C.; Prusak, Keven A.; Pennington, Todd

    2016-01-01

    Music is an everyday occurrence in a person's life. Music is heard in the workplace, in homes, and in the mall. Music can also be heard as a person exercises. Therefore, the purpose of this study was to examine the effects of music on junior high students (n = 305) step counts and time in activity in junior high school physical education classes.…

  13. The Junior High School Integrated Science: The Actual Teaching Process in the Perspective of an Ethnographer

    Science.gov (United States)

    Adu-Gyamfi, Kenneth; Ampiah, Joseph Ghartey

    2016-01-01

    Science education at the Basic School (Primary and Junior High School) serves as the foundation upon which higher levels of science education are pivoted. This ethnographic study sought to investigate the teaching of Integrated Science at the Junior High School (JHS) level in the classrooms of two science teachers in two schools of differing…

  14. The formation of logic thinking of junior schoolchildren during some extracurricular activities

    Directory of Open Access Journals (Sweden)

    Efimov Vladimir Fedorovich

    2016-04-01

    Full Text Available The article discusses the topical issue of formation of junior schoolchildren's mathematical abilities, discloses the modern scientific concept of General and specific mathematical abilities. The structure of mathematical abilities, analyzed the specificity of extra-curricular activities, which under favorable conditions accompanies the intellectual development of junior schoolchildren.

  15. Business Studies Academic Performance Differences of Secondary School Juniors in Akwa Ibom State of Nigeria

    Science.gov (United States)

    Udoukpong, Bassey E.; Emah, Ime E.; Umoren, Shirley E.

    2012-01-01

    The research examined the differences in the academic performance in Business Studies of a sampled secondary school junior students in Akwa Ibom State of Nigeria. A sample of 290 (138 male and 152 female) Junior Secondary Three (9th grade) students was surveyed. The students' variables' being examined vis-à-vis academic performance in Business…

  16. Guidelines for Professional Training of Junior Medical Staff in the Context of European Experience

    Science.gov (United States)

    Sosnova, Myroslava

    2016-01-01

    The article deals with outlining guidelines for improving professional training of junior medical staff based on European experience. Consequently, guidelines and recommendations on enhancing the efficiency of medical education in general and junior medical specialists' professional training, in particular, published by European Union of Medical…

  17. Will Aesthetics English Comic Books Make Junior High School Students Fall in Love with English Reading?

    Science.gov (United States)

    Chou, Mei-Ju; Hsu, Yung-Hung; Chen, Ching-Chi

    2015-01-01

    The present study aims to investigate the effects of Aesthetics English comic books on EFL junior high school students' vocabulary acquisition, reading comprehension, and English learning motivation. The participants in this study were 28 eighth graders from one class in a public junior high school in Pingtung in Taiwan. After ten weeks…

  18. Developing Teaching Materials PISA-Based for Mathematics and Science of Junior High School

    Science.gov (United States)

    Somakim; Suharman, Andi; Madang, Kodri; Taufiq

    2016-01-01

    This research aims to develop valid and practical teaching materials for mathematics and science lesson PISA-based for junior high school students and to determine potential effects on students in scientific activity. Subjects of this study were students of Junior High School 9 Palembang (SMP Negeri 9 Palembang). The method used in this study is…

  19. A Structural and Functional Model for Forming Management Skills in Junior Schoolchildren

    Science.gov (United States)

    Knissarina, Malika M.; Valikhanov, Sharidyar A.; Medeubayeva, Kenzhekhan T.; Zhazykova, Makpal K.; Rakhmetova, Bazar A.; Seytenova, Salima S.; Abil, Akmaral S.; Mukhangaliyeva, Shnargul Ai.

    2016-01-01

    The purpose of the study is to analyze theoretically and simulate the formation of management skills in junior schoolchildren. The authors classified junior schoolchildren's management skills, defined psychological and pedagogical principles of their formation. Empirically obtained results of questionnaires for teachers and parents (n=550)…

  20. Using Simulation to Train Junior Psychiatry Residents to Work with Agitated Patients: A Pilot Study

    Science.gov (United States)

    Zigman, Daniel; Young, Meredith; Chalk, Colin

    2013-01-01

    Objective: This article examines the benefit and feasibility of introducing a new, simulation-based learning intervention for junior psychiatry residents. Method: Junior psychiatry residents were invited to participate in a new simulation-based learning intervention focusing on agitated patients. Questionnaires were used to explore the success of…

  1. Competition Efficiency Analysis of Croatian Junior Wrestlers in European Championship

    Directory of Open Access Journals (Sweden)

    Kristijan Slacanac

    2017-06-01

    Full Text Available Croatian junior wrestler won a bronze medal at the European Championship 2016 year. Considering the potential of our wrestlers there is an obvious need of technical and tactical analysis so our juniors and seniors U23 wrestlers would be able to achieve even better results. Match analysis were conducted by LongoMatch 0.20.1. Seven matches of Croatian wrestlers were analysed. Time parameters, score efficiency, technical efficiency and tactical structure were observed and analysed from the aspect of attack and defence phase and successful/unsuccessful techniques. This paper shows descriptive parameters and competitor efficiency were calculated. The results show a great number of positive score in a standing position in relation to parterre position. The parameters of competitive efficiency (0.49 points per minute show better attacking efficiency (1.32 points per minute in relation to defence efficiency (0.83 points per minute. Croatian wrestlers achieve less score per minute in relation with elite wrestlers, but it is visible a significant progress in technical and tactical efficiency in relation in the past three year. According to place realization of technique, Croatian wrestlers realized more technique in the center, while opponents realized technique in the zone and moving to the zone. Further analysis of efficiency and individualisation training will improve efficiency of Croatian national wrestlers.

  2. Refractive Errors in State Junior High School Students in Bandung

    Directory of Open Access Journals (Sweden)

    Sabila Tasyakur Nikmah

    2016-12-01

    Full Text Available Background: Uncorrected refractive error is one of the avoidable causes of vision impairment in children and adults. Vision problem in children has been shown to affect their psychological and academic performance. This study aims at identifying and gaining more insights on the characteristic of the refractive errors in state junior high school students in Bandung to avoid uncorrected refractive errors. Methods: A cross-sectional study was conducted in September–November 2015 in state junior high schools in Bandung, West Java, Indonesia. Sample was selected using multistage random sampling technique. Children were examined using tumbling E examination; then students with visual acuity worse than 6/12 underwent Snellen Chart test, refractometry without pupil dilatation, correction with trial lens, then was followed by direct ophthalmoscopy. Results: From a total of 435 children who completed all the examination, 80 children (18.39% had refractive errors; consisted of 151 eyes (94.38% with myopia and 9 eyes (5.62% with astigmatism. Refractive errors were found to be more common in female children (73.7% than male children (26.3%. Among those with refractive errors, 45 children (56.3% did not use any corrective glasses before the examination. Conclusions: Routine refractive error test in vision screening examination is needed for students. It is equally important to raise more awareness toward eye disease in community.

  3. Why are junior doctors deterred from choosing a surgical career?

    Science.gov (United States)

    Rogers, Mary E; Creed, Peter A; Searle, Judy

    2012-05-01

    To identify the reasons why interns would not choose a surgical career. This qualitative study used semi-structured telephone interviews to explore the future career choices of 41 junior doctors (14 men, 27 women). Doctors were asked to identify specialties they would not take up, and state why this was the case. Thirty (73.2%) of the 41 interns nominated surgery as a specialty they would not choose. Themes relating to reasons for not wanting to pursue a surgical career included the lifestyle associated with surgery (66.7%), the culture within the surgical work environment (53.3%), the lack of interest in performing surgical work (36.7%), and the training requirements associated with surgery (33.3%). Both sexes had similar reasons for not wanting to choose a surgical career; but additionally, women referred to the male domination of surgery, and the difficulty and inflexibility of the training program as deterrents. Efforts are needed to promote interest in surgery as a career especially for women, to improve the surgical work environment so that medical students and junior doctors have exposure to positive role models and surgical placements, and to provide a more flexible approach to surgical training.

  4. Assessment of Turkish junior male physicians’ exposure to mobbing behavior

    Science.gov (United States)

    Sahin, Bayram; Cetin, Mehmet; Cimen, Mesut; Yildiran, Nuri

    2012-01-01

    Aim To determine the extent of Turkish junior male physicians’ exposure to mobbing behavior and its correlation with physicians' characteristics. Methods The study included physicians recruited for compulsory military service in April 2009. No sampling method was used, questionnaires were delivered to all physicians, and 278 of 292 (95%) questionnaires were returned. We used Leymann Inventory of Psychological Terror including 45 items for data collection and structural equation model for data analysis. Results A total of 87.7% of physicians experienced mobbing behavior. Physicians who worked more than 40 hours a week, single physicians, physicians working in university hospitals and private hospitals, and physicians who did not have occupational commitment were more exposed to mobbing (P Mobbing was not associated with specialty status, service period, age, and personality variables (P > 0.05). All goodness-of- fit indices of the model were acceptable (χ2 = 1.449, normed fit index = 0.955, Tucker Lewis index = 0.980, comparative fit index = 0.985, and root mean square error of approximation = 0.040). Conclusions Workplace mobbing is a critical problem for junior male physicians in Turkey. We suggest an introduction of a reporting system and education activities for physicians in high-risk groups. PMID:22911529

  5. Assessment of Turkish junior male physicians' exposure to mobbing behavior.

    Science.gov (United States)

    Sahin, Bayram; Cetin, Mehmet; Cimen, Mesut; Yildiran, Nuri

    2012-08-01

    To determine the extent of Turkish junior male physicians' exposure to mobbing behavior and its correlation with physicians' characteristics. The study included physicians recruited for compulsory military service in April 2009. No sampling method was used, questionnaires were delivered to all physicians, and 278 of 292 (95%) questionnaires were returned. We used Leymann Inventory of Psychological Terror including 45 items for data collection and structural equation model for data analysis. A total of 87.7% of physicians experienced mobbing behavior. Physicians who worked more than 40 hours a week, single physicians, physicians working in university hospitals and private hospitals, and physicians who did not have occupational commitment were more exposed to mobbing (PMobbing was not associated with specialty status, service period, age, and personality variables (P>0.05). All goodness-of- fit indices of the model were acceptable (χ(2)=1.449, normed fit index=0.955, Tucker Lewis index=0.980, comparative fit index=0.985, and root mean square error of approximation=0.040). Workplace mobbing is a critical problem for junior male physicians in Turkey. We suggest an introduction of a reporting system and education activities for physicians in high-risk groups.

  6. The importance of the junior company for an andragogy learning

    Directory of Open Access Journals (Sweden)

    David Silva Franco

    2017-12-01

    Full Text Available Andragogy is a form of teaching and learning initially aimed at the adult public, and its assumptions are directed at providing greater autonomy and participation of this public in their learning. It can be considered as a counterpoint to the traditional pedagogical aspect, which covers a methodological format, essentially applied to children, but has its model present in several higher education institutions, in which the teacher has the central role of decision making on how and what to teach This article aims to analyze, from the perceptions exposed by participants of a Junior Company, how the learning experience of the students in this organization can be related to the principles of andragogic learning. Based on the analysis of the six interviews carried out, it was verified that the experience in the junior company gives its members a greater autonomy regarding their learning, a greater comprehension and applicability of the course, as well as a better use of their baggage of particular experiences. With this study, we intend to contribute with reflections on the possibilities of improvement and development of the learning process in higher education, especially in the teaching field of Administration.

  7. Teaching English through Online Games for Junior High School Students

    Directory of Open Access Journals (Sweden)

    Sastika Seli

    2015-04-01

    Full Text Available Teaching language is an attractive activity both for the teacher and for the acceptor. They can interact together in this act. Teaching English is a challenge for the teachers to make the students interest in English because as we know English is not the first language for some countries in this world including Indonesia. There are various ways and ideas to teach English so that it can be fun and interest to be taught and to be learnt. But those ways and ideas also should be an up date method and also use a modern technology to be implemented. Along with the development of modern technology, the teachers should involve with it and make it as a part of English teaching tools. Two of the famous and sophisticated tools are computer and the internet. These things have a close relation to be urgent equipment for people. In this article, the writer wants to purpose the use of online games as a way to teach English for junior high school. Te article aims to give another teaching alternative in attracting the junior high school students to learn English in funny and enjoyable way. Through online games they do not only can play the various games but also indirectly they do the exercises of English skills.

  8. Physiological profile of senior and junior England international amateur boxers.

    Science.gov (United States)

    Smith, Marcus S

    2006-01-01

    Despite worldwide popularity of amateur boxing, research focussed on the physiological demands of the sport is limited. The physiological profile of Senior and Junior England international amateur boxers is presented. A gradual (8 to 21-days) and rapid (0 to 7-days) phase of body weight reduction was evident with 2.2 ± 0.3 % of the 7.0 ± 0. 8 % weight loss occurring over the final 24-hours. An increase in body weight >4% was observed following a recovery period. High urine osmolality values (> 1000 mOsm·kg(-1)) were recorded during training and competition. High post-competition blood lactate values (>13.5 mmol·l(-1)) highlighted the need for a well-developed anaerobic capacity and the importance of not entering the ring in a glycogen depleted state. The aerobic challenge of competition was demonstrated by maximum heart rate values being recorded during 'Open' sparring. Mean body fat values of 9-10% were similar to those reported for other weight classified athletes. Normal resting values were reported for hematocrit (Senior 48 ± 2 % and Junior 45 ± 2 %), haemoglobin (Senior 14.7 ± 1.0 g·dl(-1) and Junior 14.5 ± 0.8 g·dl(-1)), bilirubin (Senior 15.3 ± 6.2 µmol·l-1(-1)) and ferritin (Senior 63.3 ± 45.7 ng·ml(-1)). No symptoms associated with asthma or exercise-induced asthma was evident. A well- developed aerobic capacity was reflected in the Senior VO2max value of 63.8 ± 4.8 ml·kg(-1)·min(-1). Senior lead hand straight punching force (head 1722 ± 700 N and body 1682 ± 636 N) was lower than the straight rear hand (head 2643 ± 1273 N and body 2646 ± 1083 N), lead hook (head 2412 ± 813 N and body 2414 ± 718 N) and rear hook (head 2588 ± 1040 N and body 2555 ± 926 N). It was concluded that amateur boxing performance is dependent on the interplay between anaerobic and aerobic energy systems. Current weight making methods may lead to impaired substrate availability, leading to reduced competitive performance and an increased risk to a boxers

  9. Solar energy

    International Nuclear Information System (INIS)

    Kruisheer, N.

    1992-01-01

    In five brief articles product information is given on solar energy applications with special attention to the Netherlands. After an introduction on solar energy availability in the Netherlands the developments in solar boiler techniques are dealt with. Solar water heaters have advantages for the environment, and government subsidies stimulate different uses of such water heaters. Also the developments of solar cells show good prospects, not only for developing countries, but also for the industrialized countries. In brief the developments in solar energy storage and the connection of solar equipment to the grid are discussed. Finally attention is paid to the applications of passive solar energy in the housing construction, the use of transparent thermal insulation and the developments of translucent materials. 18 figs., 18 ills

  10. Solar Imagery

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of solar photographic and illustrated datasets contributed by a number of national and private solar observatories located worldwide....

  11. Solar Features

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of solar feature datasets contributed by a number of national and private solar observatories located worldwide.

  12. Solar Indices

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of indices related to solar activity contributed by a number of national and private solar observatories located worldwide. This...

  13. Energy performance assessment of Looe junior and infant school

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, D.K.; Vaughan, N.D.; Jenkins, H.G. (Welsh School of Architecture, Cardiff (GB)); O' Sullivan, P.E. (University Coll., London (GB). Bartlett School of Architecture and Planning)

    1990-01-01

    A multi-disciplinary appraisal of a passive solar primary school in Cornwall is presented. The building was found to be energy efficient and well liked by the teaching staff. Whilst problems were noted in ventilation control and air-quality the building was considered to be a successful example of passive solar design. (author).

  14. Solar Special

    International Nuclear Information System (INIS)

    Van Roekel, A.; Osborne, J.; Schroeter, S.; De Jong, R.; De Saint Jacob, Y.

    2009-01-01

    Solar power is growing much faster than most policymakers and analysts realise. As costs come down and feed-in tariffs go up across Europe, a number of countries have started in pursuit of market leader Germany. But in Germany criticism is growing of the multi-billion-euro support schemes that keep the solar industry booming. In this section of the magazine several articles are dedicated to developments in solar energy in Europe. The first article is an overview story on the strong growing global market for solar cells, mainly thanks to subsidy schemes. The second article is on the position of foreign companies in the solar market in Italy. Article number three is dedicated to the conditions for solar technology companies to establish themselves in the German state of Saxony. Also the fifth article deals with the development of solar cells in Saxony: scientists, plant manufacturers and module producers in Saxony are working on new technologies that can be used to produce solar electricity cost-effectively. The goal is to bring the price down to match that of conventionally generated electricity within the next few years. The sixth article deals with the the solar power market in Belgium, which may be overheated or 'oversubsidized'. Article seven is on France, which used to be a pioneer in solar technology, but now produces only a fraction of the solar output of market leader Germany. However, new attractive feed-in-tariffs are changing the solar landscape drastically

  15. Data acquisition and analysis of passive solar cooling effects by storage of out door air in the middle of the night; Shin'ya gaiki chikurei ni yoru shizen reibo koka no jissoku to kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Inagaki, H.; Kasutani, A. [Komazawa Womens Junior College, Tokyo (Japan); Koizumi, H.

    1998-12-05

    Passive cooling by storing coolness of out door air in the middle of the night in rock bed is realized by air type solar system without any additional equipment. The advantage of the passive cooling is confirmed with measuring performance of the passive cooling effect of air type solar system equipped in our Komazawa Womens Junior College last year. (author)

  16. Solar Indices - Solar Radio Flux

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Collection includes a variety of indices related to solar activity contributed by a number of national and private solar observatories located worldwide. This...

  17. PHYSIOLOGICAL PROFILE OF SENIOR AND JUNIOR ENGLAND INTERNATIONAL AMATEUR BOXERS

    Directory of Open Access Journals (Sweden)

    Marcus S. Smith

    2006-07-01

    Full Text Available Despite worldwide popularity of amateur boxing, research focussed on the physiological demands of the sport is limited. The physiological profile of Senior and Junior England international amateur boxers is presented. A gradual (8 to 21-days and rapid (0 to 7-days phase of body weight reduction was evident with 2.2 ± 0.3 % of the 7.0 ± 0. 8 % weight loss occurring over the final 24-hours. An increase in body weight >4% was observed following a recovery period. High urine osmolality values (> 1000 mOsm·kg-1 were recorded during training and competition. High post-competition blood lactate values (>13.5 mmol·l-1 highlighted the need for a well-developed anaerobic capacity and the importance of not entering the ring in a glycogen depleted state. The aerobic challenge of competition was demonstrated by maximum heart rate values being recorded during 'Open' sparring. Mean body fat values of 9-10% were similar to those reported for other weight classified athletes. Normal resting values were reported for hematocrit (Senior 48 ± 2 % and Junior 45 ± 2 %, haemoglobin (Senior 14.7 ± 1.0 g·dl-1 and Junior 14.5 ± 0.8 g·dl-1, bilirubin (Senior 15.3 ± 6.2 µmol·l-1-1 and ferritin (Senior 63.3 ± 45.7 ng·ml-1. No symptoms associated with asthma or exercise-induced asthma was evident. A well- developed aerobic capacity was reflected in the Senior VO2max value of 63.8 ± 4.8 ml·kg-1·min-1. Senior lead hand straight punching force (head 1722 ± 700 N and body 1682 ± 636 N was lower than the straight rear hand (head 2643 ± 1273 N and body 2646 ± 1083 N, lead hook (head 2412 ± 813 N and body 2414 ± 718 N and rear hook (head 2588 ± 1040 N and body 2555 ± 926 N. It was concluded that amateur boxing performance is dependent on the interplay between anaerobic and aerobic energy systems. Current weight making methods may lead to impaired substrate availability, leading to reduced competitive performance and an increased risk to a boxers health

  18. Isometric Mid-Thigh Pull Performance Is Associated With Athletic Performance And Sprinting Kinetics In Division I Men And Women's Basketball Players.

    Science.gov (United States)

    Townsend, Jeremy R; Bender, David; Vantrease, William; Hudy, John; Huet, Kevin; Williamson, Cassie; Bechke, Emily; Serafini, Paul; Mangine, Gerald T

    2017-07-31

    To examine the relationships between isometric mid-thigh pull (IMTP) force, athletic performance measures, and sprint kinetics in Division I men's and women's basketball players. Twenty-three (male = 8, female = 15) division 1 basketball players completed a maximal 20-m sprint trial while tethered to a device which provided kinetic feedback (peak and average sprinting power, velocity and force). Additionally, one repetition-maximal (1RM) front squat, 1RM hang clean, vertical jump height, and agility (pro-agility and lane agility) tests were performed. Rate of force development (RFD) at 50ms, 100ms, 150ms, 200ms and 250ms of IMTP, as well as peak force (PF) were also collected. Pearson product-moment correlation analysis was used to examine the relationships between these measures. Significant (p training.

  19. Listening to music during sprint interval exercise: The impact on exercise attitudes and intentions.

    Science.gov (United States)

    Stork, Matthew J; Martin Ginis, Kathleen A

    2017-10-01

    This study investigated the impact of listening to music during exercise on perceived enjoyment, attitudes and intentions towards sprint interval training (SIT). Twenty men (24.8 ± 4.5 years) and women (20.1 ± 2.6 years) unfamiliar with SIT exercise completed two acute sessions of SIT, one with and one without music. Perceived enjoyment, attitudes and intentions towards SIT were measured post-exercise for each condition. Attitudes and intentions to engage in SIT were also measured at baseline and follow-up. Post-exercise attitudes mediated the effects of enjoyment on intentions in the music condition (95% confidence interval [CI]: [0.01, 0.07], κ 2  = 0.36) and in the no music condition (95% CI: [0.01, 0.08], κ 2  = 0.37). Attitudes towards SIT were significantly more positive following the music than no music condition (P = 0.004), while intentions towards SIT were not (P = 0.29). Further, attitudes and intentions towards SIT did not change from baseline to follow-up (Ps > 0.05). These findings revealed that participants had relatively positive attitudes and intentions towards SIT, which did not become more negative despite experiencing intense SIT protocols. This study highlights the importance of acute affective responses to SIT exercise for influencing one's attitudes and intentions towards participating in SIT exercise. Such factors could ultimately play a key role in determining whether an individual engages in SIT exercise in the long term.

  20. A Correlational Analysis of Tethered Swimming, Swim Sprint Performance and Dry-land Power Assessments.

    Science.gov (United States)

    Loturco, I; Barbosa, A C; Nocentini, R K; Pereira, L A; Kobal, R; Kitamura, K; Abad, C C C; Figueiredo, P; Nakamura, F Y

    2016-03-01

    Swimmers are often tested on both dry-land and in swimming exercises. The aim of this study was to test the relationships between dry-land, tethered force-time curve parameters and swimming performances in distances up to 200 m. 10 young male high-level swimmers were assessed using the maximal isometric bench-press and quarter-squat, mean propulsive power in jump-squat, squat and countermovement jumps (dry-land assessments), peak force, average force, rate of force development (RFD) and impulse (tethered swimming) and swimming times. Pearson product-moment correlations were calculated among the variables. Peak force and average force were very largely correlated with the 50- and 100-m swimming performances (r=- 0.82 and -0.74, respectively). Average force was very-largely/largely correlated with the 50- and 100-m performances (r=- 0.85 and -0.67, respectively). RFD and impulse were very-largely correlated with the 50-m time (r=- 0.72 and -0.76, respectively). Tethered swimming parameters were largely correlated (r=0.65 to 0.72) with mean propulsive power in jump-squat, squat-jump and countermovement jumps. Finally, mean propulsive power in jump-squat was largely correlated (r=- 0.70) with 50-m performance. Due to the significant correlations between dry-land assessments and tethered/actual swimming, coaches are encouraged to implement strategies able to increase leg power in sprint swimmers. © Georg Thieme Verlag KG Stuttgart · New York.