Oxygen uptake during mini trampoline exercise in normal-weight, endurance-trained adults and in overweight-obese, inactive adults: A proof-of-concept study.

Science.gov (United States)

Höchsmann, Christoph; Rossmeissl, Anja; Baumann, Sandra; Infanger, Denis; Schmidt-Trucksäss, Arno

2018-03-15

To examine cardiorespiratory exertion during mini trampoline exercises of different intensities in both endurance-trained athletes and overweight-obese adults. Physically healthy participants (Group A: normal-weight, endurance-trained athletes; Group B: inactive, overweight-obese adults) participated in two measurement appointments and three training sessions in between appointments, in which participants familiarized themselves with the use of the mini trampoline and the execution of the exercises. The primary outcome was the ⩒O 2peak for each of the six mini trampoline exercises relative to the ⩒O 2peak as established during an all-out exercise test on a bike ergometer during the first measurement appointment. Secondary outcomes were average ⩒O 2 as well as maximum and average heart rate. The six mini trampoline exercises generated ⩒O 2peak values between 42% and 81% in the endurance-trained athletes and between 58% and 87% in the overweight-obese participants, both in relation to the bike ergometer ⩒O 2peak . Average ⩒O 2 values ranged from 35% to 69% (endurance-trained athletes) and from 48% to 71% (overweight-obese participants), depending on exercise. Average heart rate likewise lay in a range that can be categorized as moderate-to-vigorous aerobic exercise for both groups. A moderate-to-strong correlation (0.658 to 0.875, depending on exercise) between bike ergometer ⩒O 2peak and mini trampoline ⩒O 2peak was found for all six exercises. Mini trampoline exercise has the potential to produce training intensities that concur with established exercise guidelines. The exercise intensity is self-adjusting and allows for an effective and safe workout for different users with a wide range of fitness levels.

Simulating the physiology of athletes during endurance sports events: modelling human energy conversion and metabolism

NARCIS (Netherlands)

van Beek, J.H.G.M.; Supandi, F.B.; Gavai, Anand; de Graaf, A.A.; Binsl, T.W.; Hettling, H.

2011-01-01

The human physiological system is stressed to its limits during endurance sports competition events.We describe a whole body computational model for energy conversion during bicycle racing. About 23 per cent of the metabolic energy is used for muscle work, the rest is converted to heat. We

Simulating the physiology of athletes during endurance sports events: Modelling human energy conversion and metabolism

NARCIS (Netherlands)

Beek, J.H.G.M. van; Supandi, F.; Gavai, A.K.; Graaf, A.A. de; Binsl, T.W.; Hettling, H.

2011-01-01

The human physiological system is stressed to its limits during endurance sports competition events.We describe a whole body computational model for energy conversion during bicycle racing. About 23 per cent of the metabolic energy is used for muscle work, the rest is converted to heat. We

Slide-based ergometer rowing

DEFF Research Database (Denmark)

Vinther, Anders; Alkjær, T; Kanstrup, I-L

2012-01-01

Force production profile and neuromuscular activity during slide-based and stationary ergometer rowing at standardized submaximal power output were compared in 14 male and 8 female National Team rowers. Surface electromyography (EMG) was obtained in selected thoracic and leg muscles along with sy...

Validity and Reliability of the Cycleops Hammer Cycle Ergometer.

Science.gov (United States)

Lillo-Bevia, José R; Pallarés, Jesús G

2017-11-28

To validate the new drive indoor trainer Hammer designed by Cycleops®. Eleven cyclists performed 44 randomized and counterbalanced graded exercise tests (100-500W), at 70, 85 and 100 rev.min -1 cadences, in seated and standing positions, on 3 different Hammer units, while a scientific SRM system continuously recorded cadence and power output data. No significant differences were detected between the three Hammer devices and the SRM for any workload, cadence, or pedalling condition (P value between 1.00 and 0.350), except for some minor differences (P 0.03 and 0.04) found in the Hammer 1 at low workloads, and for Hammer 2 and 3 at high workloads, all in seated position. Strong ICCs were found between the power output values recorded by the Hammers and the SRM (≥0.996; P=0.001), independently from the cadence condition and seated position. Bland-Altman analysis revealed low Bias (-5.5-3.8) and low SD of Bias (2.5-5.3) for all testing conditions, except marginal values found for the Hammer 1 at high cadences and seated position (9.6±6.6). High absolute reliability values were detected for the 3 Hammers (150-500W; CVreliable device to drive and measure power output in cyclists, providing an alternative to larger and more expensive laboratory ergometers, and allowing cyclists to use their own bicycle.

Identification of the mechanical properties of bicycle tyres for modelling of bicycle dynamics

Science.gov (United States)

Doria, Alberto; Tognazzo, Mauro; Cusimano, Gianmaria; Bulsink, Vera; Cooke, Adrian; Koopman, Bart

2013-03-01

Advanced simulation of the stability and handling properties of bicycles requires detailed road-tyre contact models. In order to develop these models, in this study, four bicycle tyres are tested by means of a rotating disc machine with the aim of measuring the components of tyre forces and torques that influence the safety and handling of bicycles. The effect of inflation pressure and tyre load is analysed. The measured properties of bicycle tyres are compared with those of motorcycle tyres.

Effect of BMI on Knee Joint Torques in Ergometer Rowing

NARCIS (Netherlands)

Roemer, Karen; Hortobagyi, Tibor; Richter, Chris; Munoz-Maldonado, Yolanda; Hamilton, Stephanie

2013-01-01

Although an authoritative panel recommended the use of ergometer rowing as a non-weight-bearing form of exercise for obese adults, the biomechanical characterization of ergometer rowing is strikingly absent. We examined the interaction between body mass index (BMI) relative to the lower extremity

Influence of water-filtered infrared-A (wIRA on reduction of local fat and body weight by physical exercise

Directory of Open Access Journals (Sweden)

Schmitz, Gerd

2006-07-01

Full Text Available Aim of the study: Investigation, whether water-filtered infrared-A (wIRA irradiation during moderate bicycle ergometer endurance exercise has effects especially on local fat reduction and on weight reduction beyond the effects of ergometer exercise alone. Methods: Randomised controlled study with 40 obese females (BMI 30-40 (median: 34.5, body weight 76-125 (median: 94.9 kg, age 20-40 (median: 35.5 years, isocaloric nutrition, 20 in the wIRA group and 20 in the control group. In both groups each participant performed 3 times per week over 4 weeks for 45 minutes bicycle ergometer endurance exercise with a constant load according to a lactate level of 2 mmol/l (aerobic endurance load, as determined before the intervention period. In the wIRA group in addition large parts of the body (including waist, hip, and thighs were irradiated during all ergometries of the intervention period with visible light and a predominant part of water-filtered infrared-A (wIRA, using the irradiation unit “Hydrosun® 6000” with 10 wIRA radiators (Hydrosun® Medizintechnik, Müllheim, Germany, radiator type 500, 4 mm water cuvette, yellow filter, water-filtered spectrum 500-1400 nm around a speed independent bicycle ergometer. Main variable of interest: change of “the sum of circumferences of waist, hip, and both thighs of each patient” over the intervention period (4 weeks. Additional variables of interest: body weight, body mass index BMI, body fat percentage, fat mass, fat-free mass, water mass (analysis of body composition by tetrapolar bioimpedance analysis, assessment of an arteriosclerotic risk profile by blood investigation of variables of lipid metabolism (cholesterol, triglycerides, high density lipoproteins HDL, low density lipoproteins LDL, apolipoprotein A1, apolipoprotein B, clinical chemistry (fasting glucose, alanin-aminotransferase ALT (= glutamyl pyruvic transaminase GPT, gamma-glutamyl-transferase GGT, creatinine, albumin, endocrinology

COMPARISON OF ROWING ON A CONCEPT 2 STATIONARY AND DYNAMIC ERGOMETER

Directory of Open Access Journals (Sweden)

Aaron Benson

2011-06-01

Full Text Available Biomechanical and physiological responses to rowing 1000 m at a power output equivalent to a 2000 m race were compared in 34 collegiate rowers (17 women, 17 men rowing on a stationary and dynamic Concept 2 ergometer. Stroke ratio, peak handle force, rate of force development, impulse, and respiratory exchange ratio decreased by 15.7, 14.8, 10.9, 10.2 and 1.9%, respectively, on the dynamic ergometer. In contrast, percent time to peak force and stroke rate increased by 10.5 and 12.6%, respectively, during dynamic ergometry; the changes in stroke rate and impulse were greater for men than women. Last, VO2 was 5.1% higher and efficiency 5. 3% lower on the dynamic ergometer for men. Collegiate rowers used higher stoke rates and lower peak stroke forces to achieve a similar power output while rowing at race pace on the dynamic ergometer, which may have increased the cardiopulmonary demand and possibly reduced force production in the primary movers. Differences were more pronounced in males than females; this dichotomy may be more due to dynamic ergometer familiarity than sex

Respiratory Muscle Training and Exercise Endurance at Altitude.

Science.gov (United States)

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

2016-08-01

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

High-intensity interval training improves insulin sensitivity in older individuals

DEFF Research Database (Denmark)

Søgaard, D; Lund, M T; Scheuer, C M

2017-01-01

AIM: Metabolic health may deteriorate with age as a result of altered body composition and decreased physical activity. Endurance exercise is known to counter these changes delaying or even preventing onset of metabolic diseases. High-intensity interval training (HIIT) is a time efficient...... alternative to regular endurance exercise, and the aim of this study was to investigate the metabolic benefit of HIIT in older subjects. METHODS: Twenty-two sedentary male (n = 11) and female (n = 11) subjects aged 63 ± 1 years performed HIIT training three times/week for 6 weeks on a bicycle ergometer. Each...... HIIT session consisted of five 1-minute intervals interspersed with 1½-minute rest. Prior to the first and after the last HIIT session whole-body insulin sensitivity, measured by a hyperinsulinaemic-euglycaemic clamp, plasma lipid levels, HbA1c, glycaemic parameters, body composition and maximal oxygen...

A BIOMECHANICAL ASSESSMENT OF ERGOMETER TASK SPECIFICITY IN ELITE FLATWATER KAYAKERS

Directory of Open Access Journals (Sweden)

Neil Fleming

2012-03-01

Full Text Available The current study compared EMG, stroke force and 2D kinematics during on-ergometer and on-water kayaking. Male elite flatwater kayakers (n = 10 performed matched exercise protocols consisting of 3 min bouts at heart and stroke rates equivalent to 85% of VO2peak (assessed by prior graded incremental test. EMG data were recorded from Anterior Deltoid (AD, Triceps Brachii (TB, Latissimus Dorsi (LD and Vastus Lateralis (VL via wireless telemetry. Video data recorded at 50 Hz with audio triggers pre- and post-exercise facilitated synchronisation of EMG and kinematic variables. Force data were recorded via strain gauge arrays on paddle and ergometer shafts. EMG data were root mean squared (20ms window, temporally and amplitude normalised, and averaged over 10 consecutive cycles. In addition, overall muscle activity was quantified via iEMG and discrete stroke force and kinematic variables computed. Significantly greater TB and LD mean iEMG activity were recorded on-water (239 ± 15 vs. 179 ± 10 µV. s, p < 0.01 and 158 ± 12 vs. 137 ± 14 µV.s, p < 0.05, respectively, while significantly greater AD activity was recorded on-ergometer (494 ± 66 vs. 340 ± 35 µV.s, p < 0.01. Time to vertical shaft position occurred significantly earlier on-ergometer (p < 0.05. Analysis of stroke force data and EMG revealed that increased AD activity was concurrent with increased external forces applied to the paddle shaft at discrete phases of the on-ergometer stroke cycle. These external forces were associated with the ergometer loading mechanism and were not observed on- water. The current results contradict a previous published hypothesis on shoulder muscle recruitment during on-water kayaking.

Endurance Capacity Is Not Correlated with Endothelial Function in Male University Students

Science.gov (United States)

Wu, Fang; Su, Chen; Fan, Zhen-guo; Zhu, Zhu; Tao, Jun; Huang, Yi-jun

2014-01-01

Background Endurance capacity, assessed by 1000-meter (1000 m) run of male university students, is an indicator of cardiovascular fitness in Chinese students physical fitness surveillance. Although cardiovascular fitness is related to endothelial function closely in patients with cardiovascular diseases, it remains unclear whether endurance capacity correlates with endothelial function, especially with circulating endothelial microparticles (EMPs), a new sensitive marker of endothelial dysfunction in young students. The present study aimed to investigate the relationship between endurance capacity and endothelial function in male university students. Methods Forty-seven healthy male university students (mean age, 20.1±0.6 years; mean height, 172.4±6.3 cm; and mean weight, 60.0±8.2 kg) were recruited in this study. The measurement procedure of 1000 m run time was followed to Chinese national students Constitutional Health Criterion. Endothelium function was assessed by flow-mediated vasodilation (FMD) in the brachial artery measured by ultrasonic imaging, and the level of circulating EMPs was measured by flow cytometry. Cardiovascular fitness indicator - maximal oxygen uptake (VO2 max) - was also measured on a cycle ergometer using a portable gas analyzer. Results 1000 m run time was correlated with VO2max (r = −0.399, p0.05). Conclusion The correlations between endurance capacity or cardiovascular fitness and endothelial function were not found in healthy Chinese male university students. These results suggest that endurance capacity may not reflect endothelial function in healthy young adults with well preserved FMD and low level of circulating CD31+/CD42-EMPs. PMID:25101975

Growth hormone enhances effects of endurance training on oxidative muscle metabolism in elderly women

DEFF Research Database (Denmark)

Lange, K H; Isaksson, F; Juul, A

2000-01-01

by approximately 18% in both groups, whereas the marked increase in muscle citrate synthase activity was 50% larger in the GH group compared with the placebo group. In addition, only the GH group revealed an increase in muscle L-3-hydroxyacyl-CoA dehydrogenase activity. Body weight remained unchanged in both...... groups, but the GH group showed significant changes in body composition with a decrease in fat mass and an increase in lean body mass. Twenty-four-hour indirect calorimetry performed in four subjects showed a marked increase in energy expenditure with increased relative and absolute fat combustion...... endurance training on a cycle ergometer over 12 wk. rhGH was given in a randomized, double-blinded, placebo-controlled design in addition to the training program. GH administration resulted in a doubling of serum insulin-like growth factor I levels. With endurance training, peak oxygen uptake increased...

Endurance exercise training increases peripheral vascular response in human fingers.

Science.gov (United States)

Katayama, K; Shimoda, M; Maeda, J; Takemiya, T

1998-10-01

The purpose of this study was to clarify whether peripheral vascular response to alteration of transmural pressure is changed by endurance exercise training. The healthy male subjects (training group; n = 6) performed endurance exercise training that consisted of cycle ergometer exercise 5 d.week-1 and 30 min.d-1 for a period of 8 weeks. Changes in the peripheral vascular response to alteration of transmural pressure in the human finger were measured by a differential digital photoplethysmogram (DeltaDPG) and blood pressure during passive movement of the arm to different vertical hand positions relative to heart level. Following 8 weeks of endurance training, percent changes in DeltaDPG from heart level in the training group increased significantly (mean +/- SD, -48.1 +/- 7. 3 to -58.7 +/- 9.3% at the lowered position, 46.1 +/- 13.4 to 84.6 +/- 8.8% at the elevated position, ppressure, also significantly changed in the training group over the 8 weeks (5.6 +/- 1.3 to 2.7 +/- 1.6 mV. V-1.s-1.mmHg-1 at the lowered position, 30.0 +/- 12.4 to 54.4 +/- 18. 9 mV.V-1.s-1.mmHg-1 at the elevated position ). Maximal oxygen uptake (V.O2 max) was significantly increased in the training group. On the other hand, the control group (n = 6) showed no significant changes in all parameters for 8 weeks. Therefore these results suggest that endurance exercise training induces an increase in peripheral vascular response to alteration of transmural pressure in the human finger.

An integrated approach to bicycle safety.

NARCIS (Netherlands)

Wittink, R.D.

1997-01-01

The advantages of cycling are outlined, as well as the conditions under which use of the bicycle and the safety of cycling can he promoted. Bicycles are an attractive product. The potential to use a bicycle for trips shorter than 5 km is high and it's use can also be substantial for longer

Bilateral tension pneumothorax resulting from a bicycle-to-bicycle collision.

Science.gov (United States)

Edwin, Frank; Sereboe, Lawrence; Tettey, Mark Mawutor; Aniteye, Ernest; Bankah, Patrick; Frimpong-Boateng, Kwabena

2009-01-01

Bilateral tension pneumothorax occurring as a result of recreational activity is exceedingly rare. A 10-year-old boy with no previous respiratory symptoms was involved in a bicycle-to-bicycle collision during play. He was the only one hurt. A few hours later, he was rushed to the general casualty unit of the emergency department of our institution with respiratory distress, diminished bilateral chest excursions and diminished breath sounds. The correct diagnosis was made after a chest radiograph was obtained in the course of resuscitation at the casualty unit. Pleural space needle decompression was suggestive of tension only on the right. Bilateral tube thoracostomies provided effective relief. He was discharged from hospital after a week in excellent health. This case illustrates the need for children to have safety instruction to reduce the risks of recreational bicycling. Chest radiography may be needed to establish the diagnosis of bilateral tension pneumothorax. Needle thoracostomy decompression is not always effective.

Bicycle Purchaser Training Workshop.

Science.gov (United States)

Schwarz, William

A course was developed to provide data to buyers of new bicycles so they could make an informed decision about their purchases. The instructional systems design process (analysis, design, development, implementation, and evaluation) was used to analyze the need for a training course on buying and fitting a bicycle. Information was collected…

Bicycle Safety in Action.

Science.gov (United States)

National Commission on Safety Education, Washington, DC.

This material was designed to assist schools in teaching bicycle safety. As the population grows and competition for road space increases, it is more imperative than ever that we concentrate attention on the need for caution among pupil cyclists. The pamphlet: (1) discusses the role of bicycle safety in classroom instruction and in student…

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

Bicycle urbanism as competitive advantage in the neoliberal age

DEFF Research Database (Denmark)

Ibsen, Mikkel Elkær; Olesen, Kristian

2018-01-01

In the light of the emergent ‘bicycle renaissance’ in the US, this paper analyses the rationale basis of bicycle role model, Portland’s promotion of bicycling. By conceptualizing bicycle promotion as a ‘travelling idea’, the paper discusses the key rationales and discourses structuring how bicycl...

Road accidents involving bicycles: configurations and injuries.

Science.gov (United States)

Orsi, Chiara; Montomoli, Cristina; Otte, Dietmar; Morandi, Anna

2017-12-01

This study analyzed the most common types of accident involving bicycles and compared the frequency of injuries. The data source was the database of German In-Depth Accident Study (GIDAS). Cases consist of bicycles and their riders involved in accidents between 2000 and 2010. In most collisions, the bicycle impacted with a car. The percentage of injured bicyclists was higher in collisions with a heavy vehicle and decreased when the bicycle impacted with lighter vehicles. A high percentage of injured bicyclists in single accidents was observed; the most severe injury was more frequently to head and extremities. Accidents involving a car and a bicycle with the right of way in a bicycle path represented about 20% of involved and injured bicyclists. The ten most frequent configurations represented about 60% of involved and injured bicyclists. These results contribute to understand the dangerous scenarios for bicyclists and to suggest preventive actions.

Design and analysis of sustainable paper bicycle

Science.gov (United States)

Roni Sahroni, Taufik; Nasution, Januar

2017-12-01

This paper presents the design of sustainable paper bicycle which describes the stage by stage in the production of paper bicycle. The objective of this project is to design a sustainable paper bicycles to be used for children under five years old. The design analysis emphasizes in screening method to ensure the design fulfil the safety purposes. The evaluation concept is presented in designing a sustainable paper bicycle to determine highest rating. Project methodology is proposed for developing a sustainable paper bicycle. Design analysis of pedal, front and rear wheel, seat, and handle were presented using AutoCAD software. The design optimization was performed to fulfil the safety factors by modifying the material size and dimension. Based on the design analysis results, it is found that the optimization results met the factor safety. As a result, a sustainable paper bicycle was proposed for children under five years old.

Effect of endurance versus resistance training on quadriceps muscle dysfunction in COPD

DEFF Research Database (Denmark)

Iepsen, Ulrik Winning; Munch, Gregers Druedal Wibe; Rugbjerg, Mette

2016-01-01

INTRODUCTION: Exercise is an important countermeasure to limb muscle dysfunction in COPD. The two major training modalities in COPD rehabilitation, endurance training (ET) and resistance training (RT), may both be efficient in improving muscle strength, exercise capacity, and health-related quality...... and after the training intervention to assess muscle morphology and metabolic and angiogenic factors. Symptom burden, exercise capacity (6-minute walking and cycle ergometer tests), and vascular function were also assessed. RESULTS: Both training modalities improved symptom burden and exercise capacity...... with no difference between the two groups. The mean (SD) proportion of glycolytic type IIa muscle fibers was reduced after ET (from 48% [SD 11] to 42% [SD 10], Ptraining modality on muscle...

Energy systems contributions in 2,000 m race simulation: a comparison among rowing ergometers and water.

Science.gov (United States)

de Campos Mello, Fernando; de Moraes Bertuzzi, Rômulo Cássio; Grangeiro, Patricia Moreno; Franchini, Emerson

2009-11-01

This study investigated the energy system contributions of rowers in three different conditions: rowing on an ergometer without and with the slide and rowing in the water. For this purpose, eight rowers were submitted to 2,000 m race simulations in each of the situations defined above. The fractions of the aerobic (W (AER)), anaerobic alactic (W (PCR)) and anaerobic lactic (W ([La-])) systems were calculated based on the oxygen uptake, the fast component of excess post-exercise oxygen uptake and changes in net blood lactate, respectively. In the water, the metabolic work was significantly higher [(851 (82) kJ] than during both ergometer [674 (60) kJ] and ergometer with slide [663 (65) kJ] (P systems were water = 87 (2), 7 (2) and 6 (2)%, ergometer = 84 (2), 7 (2) and 9 (2)%, and ergometer with the slide = 84 (2), 7 (2) and 9 (1)%. VO2, HR and lactate were not different among conditions. These results seem to indicate that the ergometer braking system simulates conditions of a bigger and faster boat and not a single scull. Probably, a 2,500 m test should be used to properly simulate in the water single-scull race.

Comparative life cycle assessment of ghana-made bamboo-frame bicycle and conventional bicycles assembled and used in the Netherlands

NARCIS (Netherlands)

Agyekum, E.O.; Fortuin, K.P.J.; Harst, van der E.J.M.

2014-01-01

In order to assess the sustainability of bamboo-framed bicycles produced in Ghana, an environmental and social life cycle assessments (LCA) were performed. For the environmental LCA, a bamboo-frame bicycle was compared with aluminium- and steel-frame bicycles, focussing on processes related to the

Bicycle traffic in urban areas

Directory of Open Access Journals (Sweden)

Anđelković Zorica

2015-01-01

Full Text Available Cycling is a term describing the use of bicycles, but also any mean of transport driven solely by human power. Development of bicycle traffic in urban areas involves construction of cycling infrastructure, adapting streets and other traffic infrastructure to a form suitable for cycling and other means of transport (individual motorized traffic, public transport, walking, ensuring the adequate budget and systematic planning and development of sustainable transport in cities. The paper presents basic settings and conditions as input elements to plan bicycle traffic in urban areas, as well as program- design conditions which lead the activities of planners and designers of urban roads in connection with cyclists.

Development and Validation of an Automated Step Ergometer

Directory of Open Access Journals (Sweden)

C. de Sousa Maria do Socorro

2014-12-01

Full Text Available Laboratory ergometers have high costs, becoming inaccessible for most of the population, hence, it is imperative to develop affordable devices making evaluations like cardiorespiratory fitness feasible and easier. The objective of this study was to develop and validate an Automated Step Ergometer (ASE, adjusted according to the height of the subject, for predicting VO2max through a progressive test. The development process was comprised by three steps, the theoretical part, the prototype assembly and further validation. The ASE consists in an elevating platform that makes the step at a higher or lower level as required for testing. The ASE validation was obtained by comparing the values of predicted VO2max (equation and direct gas analysis on the prototype and on a, treadmill. For the validation process 167 subjects with average age of 31.24 ± 14.38 years, of both genders and different degrees of cardiorespiratory fitness, were randomized and divided by gender and training condition, into untrained (n=106, active (n=24 and trained (n=37 subjects. Each participant performed a progressive test on which the ASE started at the same height (20 cm for all. Then, according to the subject’s height, it varied to a maximum of 45 cm. Time in each stage and rhythm was chosen in accordance with training condition from lowest to highest (60-180 s; 116-160 bpm, respectively. Data was compared with the student’s t test and ANOVA; correlations were tested with Pearson’s r. The value of α was set at 0.05. No differences were found between the predicted VO2max and the direct gas analysis VO2max, nor between the ASE and treadmill VO2max (p= 0.365 with high correlation between ergometers (r= 0.974. The values for repeatability, reproducibility, and reliability of male and female groups measures were, respectively, 4.08 and 5.02; 0.50 and 1.11; 4.11 and 5.15. The values of internal consistency (Cronbach’s alpha among measures were all >0.90. It was verified

Effects of Combined Training with Breathing Resistance and Sustained Physical Exertion to Improve Endurance Capacity and Respiratory Muscle Function in Healthy Young Adults

OpenAIRE

Kido, Satoshi; Nakajima, Yasuhiro; Miyasaka, Tomoya; Maeda, Yusuke; Tanaka, Toshiaki; Yu, Wenwei; Maruoka, Hiroshi; Takayanagi, Kiyomi

2013-01-01

[Purpose] In this study, combined training with breathing resistance and sustained physical exertion was carried out to evaluate its physiological effects and its effect on improve endurance capacity. [Subjects and Methods] The subjects were nine healthy adults (mean age 20.4, SD ? 1.7?years). The combined training group (n = 5) carried out 6 weeks of combined training using a cycle ergometer, with exercise load tests and respiratory function tests performed before and after the training. The...

Bicycle Crashes

Data.gov (United States)

Town of Chapel Hill, North Carolina — This data set maps the locations of crashes involving bicyclists in the Chapel Hill Region of North Carolina.The data comes from police-reported bicycle-motor...

Decrease in Ionized and Total Magnesium Blood Concentrations in Endurance Athletes Following an Exercise Bout Restores within Hours-Potential Consequences for Monitoring and Supplementation.

Science.gov (United States)

Terink, Rieneke; Balvers, Michiel G J; Hopman, Maria T; Witkamp, Renger F; Mensink, Marco; Gunnewiek, Jacqueline M T Klein

2017-06-01

Magnesium is essential for optimal sport performance, generating an interest to monitor its status in athletes. However, before measuring magnesium status in blood could become routine, more insight into its diurnal fluctuations and effects of exercise itself is necessary. Therefore, we measured the effect of an acute bout of exercise on ionized (iMg) and total plasma magnesium (tMg) in blood obtained from 18 healthy well-trained endurance athletes (age, 31.1 ± 8.1 yr.; VO 2max , 50.9 ± 7.5 ml/kg/min) at multiple time points, and compared this with a resting situation. At both days, 7 blood samples were taken at set time points (8:30 fasted, 11:00, 12:30, 13:30, 15:00, 16:00, 18:30). The control day was included to correct for a putative diurnal fluctuation of magnesium. During the exercise day, athletes performed a 90 min bicycle ergometer test (70% VO 2max ) between 11:00 and 12:30. Whole blood samples were analyzed for iMg and plasma for tMg concentrations. Both concentrations decreased significantly after exercise (0.52 ± 0.04-0.45 ± 0.03 mmol/L and 0.81 ± 0.07-0.73 ± 0.06 mmol/L, respectively, p exercise. These findings suggest that timing of blood sampling to analyze Mg status is important. Additional research is needed to establish the recovery time after different types of exercise to come to a general advice regarding the timing of magnesium status assessment in practice.

Low-stress bicycling and network connectivity : [research brief].

Science.gov (United States)

2012-05-01

In one sense, a citys or regions bicycling network includes all of its roads and paths on which bicycling is permitted. However, some streets provide such a poor level of safety and comfort for bicycling that the majority of the population cons...

Safety impacts of bicycle infrastructure: A critical review.

Science.gov (United States)

DiGioia, Jonathan; Watkins, Kari Edison; Xu, Yanzhi; Rodgers, Michael; Guensler, Randall

2017-06-01

This paper takes a critical look at the present state of bicycle infrastructure treatment safety research, highlighting data needs. Safety literature relating to 22 bicycle treatments is examined, including findings, study methodologies, and data sources used in the studies. Some preliminary conclusions related to research efficacy are drawn from the available data and findings in the research. While the current body of bicycle safety literature points toward some defensible conclusions regarding the safety and effectiveness of certain bicycle treatments, such as bike lanes and removal of on-street parking, the vast majority treatments are still in need of rigorous research. Fundamental questions arise regarding appropriate exposure measures, crash measures, and crash data sources. This research will aid transportation departments with regard to decisions about bicycle infrastructure and guide future research efforts toward understanding safety impacts of bicycle infrastructure. Copyright © 2017 Elsevier Ltd and National Safety Council. All rights reserved.

Cardiovascular Response Of Diabetic And Non-Diabetic Nigerian ...

African Journals Online (AJOL)

This study assessed the cardiovascular responses of diabetic and non-diabetic subjects to a single bout of bicycle ergometry. Ten male volunteer diabetics and ten male non-diabetic healthy subjects constituted the study and control groups respectively. The subjects exercised for ten minutes on a bicycle ergometer.

The Effect of Sharrows, Painted Bicycle Lanes and Physically Protected Paths on the Severity of Bicycle Injuries Caused by Motor Vehicles.

Science.gov (United States)

Wall, Stephen P; Lee, David C; Frangos, Spiros G; Sethi, Monica; Heyer, Jessica H; Ayoung-Chee, Patricia; DiMaggio, Charles J

2016-01-01

We conducted individual and ecologic analyses of prospectively collected data from 839 injured bicyclists who collided with motorized vehicles and presented to Bellevue Hospital, an urban Level-1 trauma center in New York City, from December 2008 to August 2014. Variables included demographics, scene information, rider behaviors, bicycle route availability, and whether the collision occurred before the road segment was converted to a bicycle route. We used negative binomial modeling to assess the risk of injury occurrence following bicycle path or lane implementation. We dichotomized U.S. National Trauma Data Bank Injury Severity Scores (ISS) into none/mild (0-8) versus moderate, severe, or critical (>8) and used adjusted multivariable logistic regression to model the association of ISS with collision proximity to sharrows (i.e., bicycle lanes designated for sharing with cars), painted bicycle lanes, or physically protected paths. Negative binomial modeling of monthly counts, while adjusting for pedestrian activity, revealed that physically protected paths were associated with 23% fewer injuries. Painted bicycle lanes reduced injury risk by nearly 90% (IDR 0.09, 95% CI 0.02-0.33). Holding all else equal, compared to no bicycle route, a bicycle injury nearby sharrows was nearly twice as likely to be moderate, severe, or critical (adjusted odds ratio 1.94; 95% confidence interval (CI) 0.91-4.15). Painted bicycle lanes and physically protected paths were 1.52 (95% CI 0.85-2.71) and 1.66 (95% CI 0.85-3.22) times as likely to be associated with more than mild injury respectively.

The Effect of Sharrows, Painted Bicycle Lanes and Physically Protected Paths on the Severity of Bicycle Injuries Caused by Motor Vehicles

Directory of Open Access Journals (Sweden)

Stephen P. Wall

2016-12-01

Full Text Available We conducted individual and ecologic analyses of prospectively collected data from 839 injured bicyclists who collided with motorized vehicles and presented to Bellevue Hospital, an urban Level-1 trauma center in New York City, from December 2008 to August 2014. Variables included demographics, scene information, rider behaviors, bicycle route availability, and whether the collision occurred before the road segment was converted to a bicycle route. We used negative binomial modeling to assess the risk of injury occurrence following bicycle path or lane implementation. We dichotomized U.S. National Trauma Data Bank Injury Severity Scores (ISS into none/mild (0–8 versus moderate, severe, or critical (>8 and used adjusted multivariable logistic regression to model the association of ISS with collision proximity to sharrows (i.e., bicycle lanes designated for sharing with cars, painted bicycle lanes, or physically protected paths. Negative binomial modeling of monthly counts, while adjusting for pedestrian activity, revealed that physically protected paths were associated with 23% fewer injuries. Painted bicycle lanes reduced injury risk by nearly 90% (IDR 0.09, 95% CI 0.02–0.33. Holding all else equal, compared to no bicycle route, a bicycle injury nearby sharrows was nearly twice as likely to be moderate, severe, or critical (adjusted odds ratio 1.94; 95% confidence interval (CI 0.91–4.15. Painted bicycle lanes and physically protected paths were 1.52 (95% CI 0.85–2.71 and 1.66 (95% CI 0.85–3.22 times as likely to be associated with more than mild injury respectively.

Modeling of speed distribution for mixed bicycle traffic flow

Directory of Open Access Journals (Sweden)

Cheng Xu

2015-11-01

Full Text Available Speed is a fundamental measure of traffic performance for highway systems. There were lots of results for the speed characteristics of motorized vehicles. In this article, we studied the speed distribution for mixed bicycle traffic which was ignored in the past. Field speed data were collected from Hangzhou, China, under different survey sites, traffic conditions, and percentages of electric bicycle. The statistics results of field data show that the total mean speed of electric bicycles is 17.09 km/h, 3.63 km/h faster and 27.0% higher than that of regular bicycles. Normal, log-normal, gamma, and Weibull distribution models were used for testing speed data. The results of goodness-of-fit hypothesis tests imply that the log-normal and Weibull model can fit the field data very well. Then, the relationships between mean speed and electric bicycle proportions were proposed using linear regression models, and the mean speed for purely electric bicycles or regular bicycles can be obtained. The findings of this article will provide effective help for the safety and traffic management of mixed bicycle traffic.

Bicycle: a bioinformatics pipeline to analyze bisulfite sequencing data.

Science.gov (United States)

Graña, Osvaldo; López-Fernández, Hugo; Fdez-Riverola, Florentino; González Pisano, David; Glez-Peña, Daniel

2018-04-15

High-throughput sequencing of bisulfite-converted DNA is a technique used to measure DNA methylation levels. Although a considerable number of computational pipelines have been developed to analyze such data, none of them tackles all the peculiarities of the analysis together, revealing limitations that can force the user to manually perform additional steps needed for a complete processing of the data. This article presents bicycle, an integrated, flexible analysis pipeline for bisulfite sequencing data. Bicycle analyzes whole genome bisulfite sequencing data, targeted bisulfite sequencing data and hydroxymethylation data. To show how bicycle overtakes other available pipelines, we compared them on a defined number of features that are summarized in a table. We also tested bicycle with both simulated and real datasets, to show its level of performance, and compared it to different state-of-the-art methylation analysis pipelines. Bicycle is publicly available under GNU LGPL v3.0 license at http://www.sing-group.org/bicycle. Users can also download a customized Ubuntu LiveCD including bicycle and other bisulfite sequencing data pipelines compared here. In addition, a docker image with bicycle and its dependencies, which allows a straightforward use of bicycle in any platform (e.g. Linux, OS X or Windows), is also available. ograna@cnio.es or dgpena@uvigo.es. Supplementary data are available at Bioinformatics online.

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

Muscle Synergies of Untrained Subjects during 6 min Maximal Rowing on Slides and Fixed Ergometer

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Shazlin Shaharudin

2014-12-01

Full Text Available The slides ergometer (SE was an improvisation from fixed ergometer (FE to bridge the gap of mechanics between ergometer rowing and on-water rowing. The specific mechanical constraints of these two types of ergometers may affect the pattern of muscle recruitment, coordination and adaptation. The main purpose of this study was to evaluate the muscle synergy during 6 minutes maximal rowing on slides (SE and fixed ergometers (FE. The laterality of muscle synergy was also examined. Surface electromyography activity, power output, heart rate, stroke length and stroke rate were analyzed from nine physically active subjects to assess the rowing performance. Physically active subjects, who were not specifically trained in rowing, were chosen to exclude the training effect on muscle synergy. Principal component analysis (PCA with varimax rotation was applied to extract muscle synergy. Three muscle synergies were sufficient to explain the majority of variance in SE (94.4 ± 2.2 % and FE (92.8 ± 1.7 %. Subjects covered more rowing distance, exerted greater power output and attained higher maximal heart rate during rowing on SE than on FE. The results proved the flexibility of muscle synergy to adapt to the mechanical constraints. Rowing on SE emphasized on bi-articular muscles contrary to rowing on FE which relied on cumulative effect of trunk and upper limb muscles during propulsive phase.

Electric bicycles in The Netherlands: Current developments and future possibilities

NARCIS (Netherlands)

Rooijen, T. van

2010-01-01

Developments with electric bicycles in the Netherlands are progressing rapidly. The number of electric bicycles sold is rises every year. Cycling is a very popular mode of transport in The Netherlands. In 2008 more than one million bicycles were sold. At the moment one out of ten bicycles sold is

Safety effects of permanent running lights for bicycles

DEFF Research Database (Denmark)

Madsen, Jens Chr. Overgaard; Andersen, T.; Lahrmann, Harry

2013-01-01

, including all recorded bicycle accidents with personal injury to the participating cyclist, is 19% lower for cyclists with permanent running lights mounted; indicating that the permanent bicycle running light significantly improves traffic safety for cyclists. The study shows that use of permanent bicycle......Making the use of daytime running lights mandatory for motor vehicles is generally documented to have had a positive impact upon traffic safety. Improving traffic safety for bicyclists is a focal point in the road traffic safety work in Denmark. In 2004 and 2005 a controlled experiment including...... 3845 cyclists was carried out in Odense, Denmark in order to examine, if permanent running lights mounted to bicycles would improve traffic safety for cyclists. The permanent running lights were mounted to 1845 bicycles and the accident rate was recorded through 12 months for this treatment group...

In dubio pro silentio – Even Loud Music Does Not Facilitate Strenuous Ergometer Exercise

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Gunter Kreutz

2018-05-01

Full Text Available Background: Music listening is wide-spread in amateur sports. Ergometer exercise is one such activity which is often performed with loud music.Aim and Hypotheses: We investigated the effects of electronic music at different intensity levels on ergometer performance (physical performance, force on the pedal, pedaling frequency, perceived fatigue and heart rate in healthy adults. We assumed that higher sound intensity levels are associated with greater ergometer performance and less perceived effort, particularly for untrained individuals.Methods: Groups of high trained and low trained healthy males (N = 40; age = 25.25 years; SD = 3.89 years were tested individually on an ergometer while electronic dance music was played at 0, 65, 75, and 85 dB. Participants assessed their music experience during the experiment.Results: Majorities of participants rated the music as not too loud (65%, motivating (77.50%, appropriate for this sports exercise (90%, and having the right tempo (67.50%. Participants noticed changes in the acoustical environment with increasing intensity levels, but no further effects on any of the physical or other subjective measures were found for neither of the groups. Therefore, the main hypothesis must be rejected.Discussion: These findings suggest that high loudness levels do not positively influence ergometer performance. The high acceptance of loud music and perceived appropriateness could be based on erroneous beliefs or stereotypes. Reasons for the widespread use of loud music in fitness sports needs further investigation. Reducing loudness during fitness exercise may not compromise physical performance or perceived effort.

In dubio pro silentio – Even Loud Music Does Not Facilitate Strenuous Ergometer Exercise

Science.gov (United States)

Kreutz, Gunter; Schorer, Jörg; Sojke, Dominik; Neugebauer, Judith; Bullack, Antje

2018-01-01

Background: Music listening is wide-spread in amateur sports. Ergometer exercise is one such activity which is often performed with loud music. Aim and Hypotheses: We investigated the effects of electronic music at different intensity levels on ergometer performance (physical performance, force on the pedal, pedaling frequency), perceived fatigue and heart rate in healthy adults. We assumed that higher sound intensity levels are associated with greater ergometer performance and less perceived effort, particularly for untrained individuals. Methods: Groups of high trained and low trained healthy males (N = 40; age = 25.25 years; SD = 3.89 years) were tested individually on an ergometer while electronic dance music was played at 0, 65, 75, and 85 dB. Participants assessed their music experience during the experiment. Results: Majorities of participants rated the music as not too loud (65%), motivating (77.50%), appropriate for this sports exercise (90%), and having the right tempo (67.50%). Participants noticed changes in the acoustical environment with increasing intensity levels, but no further effects on any of the physical or other subjective measures were found for neither of the groups. Therefore, the main hypothesis must be rejected. Discussion: These findings suggest that high loudness levels do not positively influence ergometer performance. The high acceptance of loud music and perceived appropriateness could be based on erroneous beliefs or stereotypes. Reasons for the widespread use of loud music in fitness sports needs further investigation. Reducing loudness during fitness exercise may not compromise physical performance or perceived effort. PMID:29867622

In-depth analysis of bicycle hydraulic disc brakes

Science.gov (United States)

Maier, Oliver; Györfi, Benedikt; Wrede, Jürgen; Arnold, Timo; Moia, Alessandro

2017-10-01

Hydraulic Disc Brakes (HDBs) represent the most recent and innovative bicycle braking system. Especially Electric Bicycles (EBs), which are becoming more and more popular, are equipped with this powerful, unaffected by environmental influences, and low-wear type of brakes. As a consequence of the high braking performance, typical bicycle braking errors lead to more serious accidents. This is the starting point for the development of a Braking Dynamics Assistance system (BDA) to prevent front wheel lockup and nose-over (falling over the handlebars). One of the essential prerequisites for the system design is a better understanding of bicycle HDBs' characteristics. A physical simulation model and a test bench have been built for this purpose. The results of the virtual and real experiments conducted show a high correlation and allow valuable insights into HDBs on bicycles, which have not been studied scientifically in any depth so far.

Anaerobic Degradation of Bicyclic Monoterpenes in Castellaniella defragrans

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Edinson Puentes-Cala

2018-02-01

Full Text Available The microbial degradation pathways of bicyclic monoterpenes contain unknown enzymes for carbon–carbon cleavages. Such enzymes may also be present in the betaproteobacterium Castellaniella defragrans, a model organism to study the anaerobic monoterpene degradation. In this study, a deletion mutant strain missing the first enzyme of the monocyclic monoterpene pathway transformed cometabolically the bicyclics sabinene, 3-carene and α-pinene into several monocyclic monoterpenes and traces of cyclic monoterpene alcohols. Proteomes of cells grown on bicyclic monoterpenes resembled the proteomes of cells grown on monocyclic monoterpenes. Many transposon mutants unable to grow on bicyclic monoterpenes contained inactivated genes of the monocyclic monoterpene pathway. These observations suggest that the monocyclic degradation pathway is used to metabolize bicyclic monoterpenes. The initial step in the degradation is a decyclization (ring-opening reaction yielding monocyclic monoterpenes, which can be considered as a reverse reaction of the olefin cyclization of polyenes.

An international review of the frequency of single-bicycle crashes (SBCs) and their relation to bicycle modal share

DEFF Research Database (Denmark)

Schepers, Paul; Agerholm, Niels; Amoros, Emmanuelle

2015-01-01

of SBC casualties among the total number of road crash casualties increases proportionally less than the increase in bicycle modal share. Conclusions While most fatal injuries among cyclists are due to motor vehicle–bicycle crashes, most hospital admissions and emergency department attendances result...

Fatal Cervical Spine Injury Following a Bicycle Crash

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Uhrenholt Lars

2017-06-01

Full Text Available Spinal injury following direct loading of the head and neck is a rare sequel of bicycle crashes. Fatal head injuries following bicycle crashes have been described in great detail and safety measures such as bicycle helmets have been developed accordingly. Less frequently, however, potentially severe cervical spine injuries have been described. We present the case of a middle-aged female who sustained an ultimately fatal cervical spine injury following a collision with a car whilst biking wearing a helmet. We discuss the literature regarding the protective effects of bicycle helmets, the relevance to cervical spine injury and legislation on mandatory use of helmets for injury prevention.

Statewide analysis of bicycle crashes : [project summary].

Science.gov (United States)

2017-06-01

An extensive literature review was conducted to locate existing studies in four areas: (1) risk factors that affect the frequency and severity of bicycle crashes; (2) bicycle crash causes, patterns, and contributing factors; (3) network screening met...

The environmental benefits of bicycling and walking.

Science.gov (United States)

1993-01-01

Bicycling and walking are the two major non-fuel-consuming, non-polluting : forms of transportation in the United States. Millions of Americans ride : bicycles and/or walk for a wide variety of purposes --- commuting to work, as : part of their job, ...

RELATIONSHIPS BETWEEN MUSCLE FATIGUE CHARACTERISTICS AND MARKERS OF ENDURANCE PERFORMANCE

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Martyn G. Morris

2008-12-01

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

Changes of heart rate variability and prefrontal oxygenation during Tai Chi practice versus arm ergometer cycling.

Science.gov (United States)

Lu, Xi; Hui-Chan, Christina Wan-Ying; Tsang, William Wai-Nam

2016-11-01

[Purpose] Exercise has been shown to improve cardiovascular fitness and cognitive function. Whether the inclusion of mind over exercise would increase parasympathetic control of the heart and brain activities more than general exercise at a similar intensity is not known. The aim of this study was to compare the effects of Tai Chi (mind-body exercise) versus arm ergometer cycling (body-focused exercise) on the heart rate variability and prefrontal oxygenation level. [Subjects and Methods] A Tai Chi master was invited to perform Tai Chi and arm ergometer cycling with similar exercise intensity on two separate days. Heart rate variability and prefrontal oxyhemoglobin levels were measured continuously by a RR recorder and near-infrared spectroscopy, respectively. [Results] During Tai Chi exercise, spectral analysis of heart rate variability demonstrated a higher high-frequency power as well as a lower low-frequency/high-frequency ratio than during ergometer cycling, suggesting increased parasympathetic and decreased sympathetic control of the heart. Also, prefrontal oxyhemoglobin and total hemoglobin levels were higher than those during arm ergometer exercise. [Conclusion] These findings suggest that increased parasympathetic control of the heart and prefrontal activities may be associated with Tai Chi practice. Having a "mind" component in Tai Chi could be more beneficial for older adults' cardiac health and cognitive function than body-focused ergometer cycling.

Revitalization of Cycling in a Former Bicycle Kingdom: Beijing

DEFF Research Database (Denmark)

Zhao, Chunli; Carstensen, Trine Agervig; Olafsson, Anton Stahl

This paper scrutinizes and analyses the relevant historical policy documents chronologically - from the 1960s to the present - in order to figure out the potentials of revitalizing the bicycle mode share in Beijing. Firstly, we targeted two top-drawer conflicts of the bicycle use, which are travel......- or commuting distance and motorised vehicle-oriented urban development. Secondly, we analysed how the various related policies resulted in the changing landscape of the bicycle mode share, including increasing in the bicycle mode share, created the conflicts and declined the bicycle mode share. The results...... are revealed by collection and analysis of historical material and interviews with key stakeholders. The historical material is obtained from libraries, online resources, and reports from professionals including urban designers, transportation engineers, research centres and politicians of the Beijing...

Evaluation electric bicycles; Evaluation velos electriques

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-10-01

Leovelo service is the first measure in favor of the bicycle to control the air pollution and to conserve energy. It provides in the city of Clermont-Ferrand (France) a service of bicycle hiring. This document evaluates the project after two years of operating. It provides a technical evaluation (maintenance, equipment, financing) and also the socio-economic impacts. (A.L.B.)

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

Science.gov (United States)

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

2009-07-01

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

MOTION CAPTURE AS A MODERN TECHNOLOGY FOR ANALYSING ERGOMETER ROWING

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Maria Skublewska-Paszkowska

2016-03-01

Full Text Available The paper presents a purpose-built laboratory stand consisting of a Vicon motion capture system with reference video cameras, wireless EMG system, Concept 2 Indoor Rower ergometer, wireless heart rate monitor and the Nexus software. A pilot study of people who exercise on the ergometer helped to create a proper configuration of all the components of the laboratory. Moreover, a procedure for carrying out research was developed, which consists of several steps divided into 4 stages: preparation of the motion acquisition system; preparation of the participant; familiarising participants with the technique of rowing, recording their movements and acquiring other measurement signals. Preliminary analysis of the results obtained from heterogeneous signals from various devices showed that all the components of the research stand are mutually compatible and the received signals do not interfere with one another.

Finding the Speed of a Bicycle in Circular Motion by Measuring the Lean Angle of the Bicycle

Science.gov (United States)

Ben-Abu, Yuval; Wolfson, Ira; Yizhaq, Hezi

2018-01-01

We suggest an activity for measuring the speed of a bicycle going in circular motion by measuring the bicycle's lean angle. In this activity students will be able to feel the strength that is being activated on their bodies while they are moving in circular motion. They will also understand that it is impossible to ride in a circle without the…

Cyclists' attitudes toward policies encouraging bicycle travel: findings from the Taupo Bicycle Study in New Zealand.

Science.gov (United States)

Tin Tin, Sandar; Woodward, Alistair; Thornley, Simon; Langley, John; Rodgers, Anthony; Ameratunga, Shanthi

2010-03-01

Utility cycling provides substantial health, environmental and economic benefits. Despite a favourable trend in leisure-time cycling, cycling is infrequently used for everyday travel needs in New Zealand. This study investigated cyclists' attitudes toward environmental and policy measures that would encourage them to cycle more, particularly for a trip to work. A cross-sectional analysis was undertaken using baseline data obtained from the Taupo Bicycle Study, a web-based longitudinal study. The study population comprised 2469 cyclists, aged 16 years or over, who had enrolled in the 2006 Wattyl Lake Taupo Cycle Challenge. The majority (88%) reported the provision of bicycle lanes as an important factor that would encourage them to cycle more often, followed by bicycle paths (76%), better bicycle security (64%), reduced motor vehicle speed (55%) and bike friendly public transport (38%). Of those who reported travelling to work at least once a week (N = 2223), varying proportions reported shower facilities at work (61%), fewer difficult intersections (43%), rising fuel costs (41%), fewer car parks (27%), bike designed to commute (26%) and rising cost of car parking (25%) as important factors that would encourage them to cycle to work more often. There were important differences in these perceived influences defined by the participants' socio-demographic characteristics and current cycling habits.

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

Science.gov (United States)

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

2018-03-01

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

A scientific nutrition strategy improves time trial performance by ≈6% when compared with a self-chosen nutrition strategy in trained cyclists: a randomized cross-over study.

Science.gov (United States)

Hottenrott, Kuno; Hass, Erik; Kraus, Manon; Neumann, Georg; Steiner, Martin; Knechtle, Beat

2012-08-01

We investigated whether an athlete's self-chosen nutrition strategy (A), compared with a scientifically determined one (S), led to an improved endurance performance in a laboratory time trial after an endurance exercise. S consisted of about 1000 mL·h(-1) fluid, in portions of 250 mL every 15 min, 0.5 g sodium·L(-1), 60 g glucose·h(-1), 30 g fructose·h(-1), and 5 mg caffeine·kg body mass(-1). Eighteen endurance-trained cyclists (16 male; 2 female) were tested using a randomized crossover-design at intervals of 2 weeks, following either A or S. After a warm-up, a maximal oxygen uptake test was performed. Following a 30-min break, a 2.5-h endurance exercise on a bicycle ergometer was carried out at 70% maximal oxygen uptake. After 5 min of rest, a time trial of 64.37 km (40 miles) was completed. The ingested nutrition was recorded every 15 min. In S, the athletes completed the time trial faster (128 vs. 136 min; p ≤ 0.001) and with a significantly higher power output (212 vs. 184 W; p ≤ 0.001). The intake of fluid, energy (carbohydrate-, mono-, and disaccharide), and sodium was significantly higher in S compared with A (p ≤ 0.001) during the endurance exercise. In the time trial, only sodium intake was significantly higher in S (p ≤ 0.001). We concluded that a time trial performance after a 2.5-h endurance exercise in a laboratory setting was significantly improved following a scientific nutrition strategy.

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.

Do Online Bicycle Routing Portals Adequately Address Prevalent Safety Concerns?

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Martin Loidl

2018-03-01

Full Text Available Safety concerns are among the most prevalent deterrents for bicycling. The provision of adequate bicycling infrastructure is considered as one of the most efficient means to increase cycling safety. However, limited public funding does not always allow agencies to implement cycling infrastructure improvements at the desirable level. Thus, bicycle trip planners can at least partly alleviate the lack of adequate infrastructure by recommending optimal routes in terms of safety. The presented study provides a systematic review of 35 bicycle routing applications and analyses to which degree they promote safe bicycling. The results show that most trip planners lack corresponding routing options and therefore do not sufficiently address safety concerns of bicyclists. Based on these findings, we developed recommendations on how to better address bicycling safety in routing portals. We suggest employing current communication technology and analysis to consider safety concerns more explicitly.

SOFIE, a bicycle that supports older cyclists?

NARCIS (Netherlands)

Dubbeldam, R.; Baten, C.; Buurke, J. H.; Rietman, J. S.

2017-01-01

Older cyclists remain at high risk of sustaining an injury after a fall with their bicycle. A growing awareness for the need and possibilities to support safety of older cyclists has been leading to bicycle design ideas. However, the effectiveness and acceptance of such designs has not been studied

Vision-Based Bicycle Detection Using Multiscale Block Local Binary Pattern

Directory of Open Access Journals (Sweden)

Hongyu Hu

2014-01-01

Full Text Available Bicycle traffic has heavy proportion among all travel modes in some developing countries, which is crucial for urban traffic control and management as well as facility design. This paper proposes a real-time multiple bicycle detection algorithm based on video. At first, an effective feature called multiscale block local binary pattern (MBLBP is extracted for representing the moving object, which is a well-classified feature to distinguish between bicycles and nonbicycles; then, a cascaded bicycle classifier trained by AdaBoost algorithm is proposed, which has a good computation efficiency. Finally, the method is tested with video sequence captured from the real-world traffic scenario. The bicycles in the test scenario are successfully detected.

The role of eccentric regime of leg muscle work in alpine skiing

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Ropret Robert

2017-01-01

Full Text Available Alpine skiing is characterized by a great number of leg movements with muscle contractions in eccentric regime. The role of these movements is to absorb gravitation and inertial forces, manage skis more precisely and maintain balance. Recent studies have determined the volume, duration and intenisty of eccentric contractions as well as the basic characteristics of movement amplitudes and velocities. Based on the previous findings the experiments involving eccentric training using a bicycle ergometer confirmed a positive impact that this kind of training has on increasing maximum power, strength, endurance, coordination, injury prevention, metabolic work efficiency, more efficient work with longer muscle length and its role in miming skiers' movements. This paper is an review of the studies so far in the field of kinematics, skiing dynamics and the effect of eccentric training on the development of athletes' performances.

Effects of Hemopure on maximal oxygen uptake and endurance performance in healthy humans.

Science.gov (United States)

Ashenden, M J; Schumacher, Y O; Sharpe, K; Varlet-Marie, E; Audran, M

2007-05-01

Haemoglobin-based oxygen carriers (HBOCs) such as Hemopure are touted as a tenable substitute for red blood cells and therefore potential doping agents, although the mechanisms of oxygen transport of HBOCs are incompletely understood. We investigated whether infusion of Hemopure increased maximal oxygen uptake (V.O 2max) and endurance performance in healthy subjects. Twelve male subjects performed two 4-minute submaximal exercise bouts equivalent to 60 % and 75 % of V.O (2max) on a cycle ergometer, followed by a ramped incremental protocol to elicit V.O (2max). A crossover design tested the effect of infusing either 30 g (6 subjects) or 45 g (6 subjects) of Hemopure versus a placebo. Under our study conditions, Hemopure did not increase V.O (2max) nor endurance performance. However, the infusion of Hemopure caused a decrease in heart rate of approximately 10 bpm (p=0.009) and an average increase in mean ( approximately 7 mmHg) and diastolic blood pressure ( approximately 8 mmHg) (p=0.046) at submaximal and maximal exercise intensities. Infusion of Hemopure did not bestow the same physiological advantages generally associated with infusion of red blood cells. It is conceivable that under exercise conditions, the hypertensive effects of Hemopure counter the performance-enhancing effect of improved blood oxygen carrying capacity.

Bicyclic peptide inhibitor of urokinase-type plasminogen activator

DEFF Research Database (Denmark)

Roodbeen, Renée; Jensen, Berit Paaske; Jiang, Longguang

2013-01-01

The development of protease inhibitors for pharmacological intervention has taken a new turn with the use of peptide-based inhibitors. Here, we report the rational design of bicyclic peptide inhibitors of the serine protease urokinase-type plasminogen activator (uPA), based on the established...... investigated the solution structures of the bicyclic peptide by NMR spectroscopy to map possible conformations. An X-ray structure of the bicyclic-peptide-uPA complex confirmed an interaction similar to that for the previous upain-1/upain-2-uPA complexes. These physical studies of the peptide...

The relationship between bicycle commuting and perceived stress: a cross-sectional study.

Science.gov (United States)

Avila-Palencia, Ione; de Nazelle, Audrey; Cole-Hunter, Tom; Donaire-Gonzalez, David; Jerrett, Michael; Rodriguez, Daniel A; Nieuwenhuijsen, Mark J

2017-06-23

Active commuting - walking and bicycling for travel to and/or from work or educational addresses - may facilitate daily, routine physical activity. Several studies have investigated the relationship between active commuting and commuting stress; however, there are no studies examining the relationship between solely bicycle commuting and perceived stress, or studies that account for environmental determinants of bicycle commuting and stress. The current study evaluated the relationship between bicycle commuting, among working or studying adults in a dense urban setting, and perceived stress. A cross-sectional study was performed with 788 adults who regularly travelled to work or study locations (excluding those who only commuted on foot) in Barcelona, Spain. Participants responded to a comprehensive telephone survey concerning their travel behaviour from June 2011 through to May 2012. Participants were categorised as either bicycle commuters or non-bicycle commuters, and (based on the Perceived Stress Scale, PSS-4) as either stressed or non-stressed. Multivariate Poisson regression with robust variance models of stress status based on exposures with bicycle commuting were estimated and adjusted for potential confounders. Bicycle commuters had significantly lower risk of being stressed than non-bicycle commuters (Relative Risk; RR (95% CI)=0.73 (0.60 to 0.89), p=0.001). Bicycle commuters who bicycled 4 days per week (RR (95% CI)=0.42 (0.24 to 0.73), p=0.002) and those who bicycled 5 or more days per week (RR (95% CI)=0.57 (0.42 to 0.77), pstressed than those who bicycled less than 4 days. This relationship remained statistically significant after adjusting for individual and environmental confounders and when using different cut-offs of perceived stress. Stress reduction may be an important consequence of routine bicycle use and should be considered by decision makers as another potential benefit of its promotion. © Article author(s) (or their employer

Butchers and Bicycles

DEFF Research Database (Denmark)

Kahle, Lynn; Eriksen, Steen Mandsfelt

2016-01-01

Morten Wagener is a Danish design, and innovator who founded the cargo and personal transportation bicycle company, ”Butchers and Bicycles,”. He identified a business opportunity to improve the future of urban transport. His idea was that most of the trikes) on the market lacked good design......, maneuverability and styling. With his engineering and design background, Wagener set out to design a new trike; which would meet the needs of the target market, which his research identified as well- educated individuals who were very interested in aesthetics. Furthermore, Wagener was convinced that trikes were...... between order and delivery. From a marketing perspective, one of the differentiating factors of Morten’s product is the quality of the ride (compared to competing products) and so his marketing team coined the slogan “Built-to-Tilt” because even though it’s a trike it feels like riding a two...

A study on electric bicycle energy efficiency

Directory of Open Access Journals (Sweden)

Ivan EVTIMOV

2015-09-01

Full Text Available The paper presents a construction of an experimental electric bicycle for evaluation of the energy efficiency. The bicycle is equipped with onboard computer which can store the information about motion and energy consumption. The result concerning power, energy consumption, recharging during brake process, etc. are given. Energy consumption for 3 typical city routes is studied.

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

Science.gov (United States)

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

2012-08-01

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

The spatio-temporal Development of Copenhagen's bicycle infrastructure 1912-2013

DEFF Research Database (Denmark)

Carstensen, Trine Agervig; Olafsson, Anton Stahl; Bech, Nynne Marie

2015-01-01

Cycling plays an important role in low-carbon transitions. Around the globe, cities are constructing bicycle infrastructure. The city of Copenhagen has a bicycle-friendly infrastructure celebrated for its fine-meshed network. This study documents the spatio-temporal development of Copenhagen......’s bicycle infrastructure and explores how the development corresponds to other processes of urban transformation. The study builds on historical maps of bicycle infrastructure that are digitised into geographical information, which allows for a comprehensive analysis of the formation of the network....... In search for identifying drivers, the study analyses the city’s spatial growth pattern, migration pattern, development of road network and changes in the transport culture. Analyses reveal that the bicycle infrastructure expanded at a relatively constant pace during distinct periods of urban transformation...

Finding the speed of a bicycle in circular motion by measuring the lean angle of the bicycle

Science.gov (United States)

Ben-Abu, Yuval; Wolfson, Ira; Yizhaq, Hezi

2018-05-01

We suggest an activity for measuring the speed of a bicycle going in circular motion by measuring the bicycle’s lean angle. In this activity students will be able to feel the strength that is being activated on their bodies while they are moving in circular motion. They will also understand that it is impossible to ride in a circle without the bicycle leaning at an angle, an action that is performed intuitively.

Bicycle safety education for children from a developmental and learning perspective.

Science.gov (United States)

2014-01-01

When children ride bicycles in and near traffic, they engage in a complicated task of combining motor skills and cognitive skills. In addition to developing bicycle-handling skills, bicycle safety education programs teach children how to ride safely ...

Synthetic strategy for bicyclic tetrapeptides HDAC inhibitors using ...

Indian Academy of Sciences (India)

Cyclic peptides show diverse biological activities and are considered as good therapeutic agents due to structural rigidity, receptor selectivity and biochemical stability. We have developed bicyclic tetrapeptide HDAC inhibitors based on different cyclic tetrapeptide scaffolds. For the synthesis of these bicyclic tetrapeptides, ...

40 CFR 52.1162 - Regulation for bicycle use.

Science.gov (United States)

2010-07-01

... safety education for bicyclists, motorists, children, students, street maintenance personnel and... as for a program of bicycle safety education including the motor vehicle operators license... bicycles share road space with motorized vehicles. (5) Bikeway means bike paths, bike lanes and bike routes...

Safety effects of permanent running lights for bicycles

DEFF Research Database (Denmark)

Madsen, Jens Chr. Overgaard; Andersen, T.; Lahrmann, Harry

2013-01-01

Making the use of daytime running lights mandatory for motor vehicles is generally documented to have had a positive impact upon traffic safety. Improving traffic safety for bicyclists is a focal point in the road traffic safety work in Denmark. In 2004 and 2005 a controlled experiment including...... 3845 cyclists was carried out in Odense, Denmark in order to examine, if permanent running lights mounted to bicycles would improve traffic safety for cyclists. The permanent running lights were mounted to 1845 bicycles and the accident rate was recorded through 12 months for this treatment group...... and 2000 other bicyclists, the latter serving as a control group without bicycle running lights. The safety effect of the running lights is analysed by comparing incidence rates – number of bicycle accidents recorded per man-month – for the treatment group and the control group. The incidence rate...

Reduced Dynamics of the Non-holonomic Whipple Bicycle

Science.gov (United States)

Boyer, Frédéric; Porez, Mathieu; Mauny, Johan

2018-06-01

Though the bicycle is a familiar object of everyday life, modeling its full nonlinear three-dimensional dynamics in a closed symbolic form is a difficult issue for classical mechanics. In this article, we address this issue without resorting to the usual simplifications on the bicycle kinematics nor its dynamics. To derive this model, we use a general reduction-based approach in the principal fiber bundle of configurations of the three-dimensional bicycle. This includes a geometrically exact model of the contacts between the wheels and the ground, the explicit calculation of the kernel of constraints, along with the dynamics of the system free of any external forces, and its projection onto the kernel of admissible velocities. The approach takes benefits of the intrinsic formulation of geometric mechanics. Along the path toward the final equations, we show that the exact model of the bicycle dynamics requires to cope with a set of non-symmetric constraints with respect to the structural group of its configuration fiber bundle. The final reduced dynamics are simulated on several examples representative of the bicycle. As expected the constraints imposed by the ground contacts, as well as the energy conservation, are satisfied, while the dynamics can be numerically integrated in real time.

Bicycling to school improves the cardiometabolic risk factor profile

DEFF Research Database (Denmark)

Ostergaard, Lars; Børrestad, Line A B; Tarp, Jakob

2012-01-01

To investigate whether bicycling to school improves cardiometabolic risk factor profile and cardiorespiratory fitness among children.......To investigate whether bicycling to school improves cardiometabolic risk factor profile and cardiorespiratory fitness among children....

Using crowdsourcing to prioritize bicycle network improvements : final report.

Science.gov (United States)

2016-04-01

Effort to improve the bicycle route network using crowdsourced data is a powerful means : of incorporating citizens in infrastructure improvement decisions, which will improve : livability by maximizing the benefit of the bicycle infrastructure fundi...

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.

An Operator's Guide to Safe and Enjoyable Bicycling.

Science.gov (United States)

San Jose Dept. of Public Works, CA.

Addressed to young persons and adults, this booklet delineates the duties and rights applicable to bicyclists as drivers of vehicles. The following topics are discussed: Rules of the road, defensive bicycling techniques, the bicycle as a machine, registration and theft prevention, walking the bike, bike routes, and recreational and group rides.…

Characterizing the speed and paths of shared bicycles in Lyon

OpenAIRE

Jensen , Pablo; Rouquier , Jean-Baptiste; Ovtracht , Nicolas; Robardet , Céline

2010-01-01

Thanks to numerical data gathered by Lyon's shared bicycling system V\\'elo'v, we are able to analyze 11.6 millions bicycle trips, leading to the first robust characterization of urban bikers' behaviors. We show that bicycles outstrip cars in downtown Lyon, by combining high speed and short paths.These data also allows us to calculate V\\'elo'v fluxes on all streets, pointing to interesting locations for bike paths.

Fluid Mechanics of a High Performance Racing Bicycle Wheel

Science.gov (United States)

Mercat, Jean-Pierre; Cretoux, Brieuc; Huat, Francois-Xavier; Nordey, Benoit; Renaud, Maxime; Noca, Flavio

2013-11-01

In 2012, MAVIC released the most aerodynamic bicycle wheel on the market, the CXR 80. The french company MAVIC has been a world leader for many decades in the manufacturing of bicycle wheels for competitive events such as the Olympic Games and the Tour de France. Since 2010, MAVIC has been in a research partnership with the University of Applied Sciences in Geneva, Switzerland, for the aerodynamic development of bicycle wheels. While most of the development up to date has been performed in a classical wind tunnel, recent work has been conducted in an unusual setting, a hydrodynamic towing tank, in order to achieve low levels of turbulence and facilitate quantitative flow visualization (PIV). After a short introduction on the aerodynamics of bicycle wheels, preliminary fluid mechanics results based on this novel setup will be presented.

Effects of different modes of exercise on appetite and appetite-regulating hormones.

Science.gov (United States)

Kawano, Hiroshi; Mineta, Mayuko; Asaka, Meiko; Miyashita, Masashi; Numao, Shigeharu; Gando, Yuko; Ando, Takafumi; Sakamoto, Shizuo; Higuchi, Mitsuru

2013-07-01

The present study determined the changes in appetite and appetite-regulating gut hormones during and following bouts of both rope skipping exercise (weight-bearing) and bicycle ergometer exercise (non-weight-bearing). After a 12-h fast, 15 young men (mean ± SD, age 24.4 ± 1.7 yrs, maximal oxygen uptake 47.0 ± 6.5 mL/kg/min) participated in three 160 min trials: (1) rope skipping exercise (295 ± 40 kcal, 3 sets × 10 min with 5-min interval, then rested for 120 min); (2) bicycle ergometer exercise (288 ± 36 kcal, 3 sets × 10 min with 5-min interval, then rested for 120 min); (3) control (rested for 160 min). Ratings of perceived hunger and acylated ghrelin were suppressed and total peptide YY (PYY) were increased during and immediately after exercise in both exercise trials, but glucagon liked peptide-1 was not changed. Furthermore, suppressed hunger during rope skipping exercise was greater than that during bicycle ergometer exercise, but there were no differences in acylated ghrelin and total PYY. These results indicate that weight-bearing exercise has a greater exercise-induced appetite suppressive effect compared with non-weight-bearing exercise, and both forms of exercise lowered acylated ghrelin and increased total PYY, but the changes did not differ significantly between exercise modes. Copyright © 2013 Elsevier Ltd. All rights reserved.

Use and activity levels on newly built bicycle playgrounds

DEFF Research Database (Denmark)

Schipperijn, Jasper; Hansen, Christine Kier; Rask, Simon

2015-01-01

Increasing the use of urban green space (UGS) as well as increasing cycling could potentially help address the growing inactivity problem. Three bicycle playgrounds were designed based on a participatory process and afterwards constructed in the UGS along a cycle-route on the historic outer defence...... close to one of the sites. A future study involving objective before and after measures when a new bicycle playground is build will be needed to reveal if bicycle playgrounds can provide additional activity to its users, or ‘just’ a different type of activity, in a different location....

An improved multi-value cellular automata model for heterogeneous bicycle traffic flow

Energy Technology Data Exchange (ETDEWEB)

Jin, Sheng [College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, 310058 China (China); Qu, Xiaobo [Griffith School of Engineering, Griffith University, Gold Coast, 4222 Australia (Australia); Xu, Cheng [Department of Transportation Management Engineering, Zhejiang Police College, Hangzhou, 310053 China (China); College of Transportation, Jilin University, Changchun, 130022 China (China); Ma, Dongfang, E-mail: mdf2004@zju.edu.cn [Ocean College, Zhejiang University, Hangzhou, 310058 China (China); Wang, Dianhai [College of Civil Engineering and Architecture, Zhejiang University, Hangzhou, 310058 China (China)

2015-10-16

This letter develops an improved multi-value cellular automata model for heterogeneous bicycle traffic flow taking the higher maximum speed of electric bicycles into consideration. The update rules of both regular and electric bicycles are improved, with maximum speeds of two and three cells per second respectively. Numerical simulation results for deterministic and stochastic cases are obtained. The fundamental diagrams and multiple states effects under different model parameters are analyzed and discussed. Field observations were made to calibrate the slowdown probabilities. The results imply that the improved extended Burgers cellular automata (IEBCA) model is more consistent with the field observations than previous models and greatly enhances the realism of the bicycle traffic model. - Highlights: • We proposed an improved multi-value CA model with higher maximum speed. • Update rules are introduced for heterogeneous bicycle traffic with maximum speed 2 and 3 cells/s. • Simulation results of the proposed model are consistent with field bicycle data. • Slowdown probabilities of both regular and electric bicycles are calibrated.

An improved multi-value cellular automata model for heterogeneous bicycle traffic flow

International Nuclear Information System (INIS)

Jin, Sheng; Qu, Xiaobo; Xu, Cheng; Ma, Dongfang; Wang, Dianhai

2015-01-01

This letter develops an improved multi-value cellular automata model for heterogeneous bicycle traffic flow taking the higher maximum speed of electric bicycles into consideration. The update rules of both regular and electric bicycles are improved, with maximum speeds of two and three cells per second respectively. Numerical simulation results for deterministic and stochastic cases are obtained. The fundamental diagrams and multiple states effects under different model parameters are analyzed and discussed. Field observations were made to calibrate the slowdown probabilities. The results imply that the improved extended Burgers cellular automata (IEBCA) model is more consistent with the field observations than previous models and greatly enhances the realism of the bicycle traffic model. - Highlights: • We proposed an improved multi-value CA model with higher maximum speed. • Update rules are introduced for heterogeneous bicycle traffic with maximum speed 2 and 3 cells/s. • Simulation results of the proposed model are consistent with field bicycle data. • Slowdown probabilities of both regular and electric bicycles are calibrated

Sociodemographic Factors, Population Density, and Bicycling for Transportation in the United States.

Science.gov (United States)

Nehme, Eileen K; Pérez, Adriana; Ranjit, Nalini; Amick, Benjamin C; Kohl, Harold W

2016-01-01

Transportation bicycling is a behavior with demonstrated health benefits. Population-representative studies of transportation bicycling in United States are lacking. This study examined associations between sociodemographic factors, population density, and transportation bicycling and described transportation bicyclists by trip purposes, using a US-representative sample. This cross-sectional study used 2009 National Household Travel Survey datasets. Associations among study variables were assessed using weighted multivariable logistic regression. On a typical day in 2009, 1% of Americans older than 5 years of age reported a transportation bicycling trip. Transportation cycling was inversely associated with age and directly with being male, with being white, and with population density (≥ 10,000 vs transportation. Twenty-one percent of transportation bicyclists reported trips to work, whereas 67% reported trips to social or other activities. Transportation bicycling in the United States is associated with sociodemographic characteristics and population density. Bicycles are used for a variety of trip purposes, which has implications for transportation bicycling research based on commuter data and for developing interventions to promote this behavior.

Successful Swiss solar bicycles in Australia

International Nuclear Information System (INIS)

Hansen, K.

2000-01-01

The article takes a look at the Swiss 'Spirit of Bike' team's success in the 'Power Challenge' race across Australia using solar-bicycles based on commercially available models. Apart from the sporting aspects of race, technical details on the cycles and their supply of solar power are given. Also, the history behind the success of the team is presented and the monitoring of man (and woman) and machine during the race is described. The article also discusses the electric bicycles that are commercially available and the potential of these energy-efficient vehicles in Switzerland

On the influence of tyre and structural properties on the stability of bicycles

Science.gov (United States)

Doria, Alberto; Roa Melo, Sergio Daniel

2018-06-01

In recent years the Whipple Carvallo Bicycle Model has been extended to analyse high speed stability of bicycles. Various researchers have developed models taking into account the effects of front frame compliance and tyre properties, nonetheless, a systematic analysis has not been yet carried out. This paper aims at analysing parametrically the influence of front frame compliance and tyre properties on the open loop stability of bicycles. Some indexes based on the eigenvalues of the dynamic system are defined to evaluate quantitatively bicycle stability. The parametric analysis is carried out with a factorial design approach to determine the most influential parameters. A commuting and a racing bicycle are considered and numerical results show different effects of the various parameters on each bicycle. In the commuting bicycle, the tyre properties have greater influence than front frame compliance, and the weave mode has the main effect on stability. Conversely, in the racing bicycle, the front frame compliance parameters have greater influence than tyre properties, and the wobble mode has the main effect on stability.

Associations between bicycling and carotid arterial stiffness in adolescents

DEFF Research Database (Denmark)

Ried-Larsen, M; Grøntved, A; Østergaard, Lars

2015-01-01

Youth Heart Study. Total frequency of bicycle usage was assessed by self-report, and carotid arterial stiffness was assessed using B-mode ultrasound. After adjusting for pubertal status, body height, and objectively measured physical activity and other personal lifestyle and demographic factors, boys......The aim of the study was to investigate the associations between bicycling and carotid arterial stiffness, independent of objectively measured moderate-and-vigorous physical activity. This cross-sectional study included 375 adolescents (age 15.7 ± 0.4 years) from the Danish site of the European...... using their bicycle every day of the week displayed a higher carotid arterial compliance {standard beta 0.47 [95% confidence interval (CI) 0.07-0.87]} and distension [standard beta 0.38 (95% CI -0.04 to 0.81)]. Boys using their bicycle every day of the week furthermore displayed a lower Young's elastic...

Johnson Space Center's Free Range Bicycle Program.- Fall 2015 Intern Report

Science.gov (United States)

Lee-Stockton, Willem

2015-01-01

NASA's Johnson Space Center is a big place, encompassing 1,620 acres and more than a hundred buildings. Furthermore, there are reportedly 15 thousand employees, all of which have somewhere to be. To facilitate the movement of all these people JSC has historically relied on human power. Pedaling their way towards deep space, bicycles have been the go to method. Currently there are about 200 Free Range Bicycles at JSC. Free Range Bicycles belong to nobody, except NASA, and are available for anybody to use. They are not to be locked or hidden (although frequently are) and the intention is that there will always be a bike to hop on to get where you're going (although it may not be the bike you rode in on). Although not without its own shortcomings, the Free Range Bicycle Program has continued to provide low cost, simple transportation for NASA's JSC. In addition to the approximately 200 Free Range Bicycles, various larger divisions (like engineering) will often buy a few dozen bikes for their team members to use or individuals will bring their own personal bike to either commute or use on site. When these bicycles fall into disrepair or are abandoned (from retirees etc) they become a problem at JSC. They are an eye sore, create a safety hazard and make it harder to find a working bike in a time of need. The Free Range Program hopes to address this first problem by "tagging out" abandoned or out of service bicycles. A bright orange "DO NOT OPERATE" tag is placed on the bike and given a serial number for tracking purposes. See picture to the right. If the bike has an active owner with intentions to repair the bike the bottom of the tag has instructions for how to claim the abandoned bicycle. After being tagged the owner of the bicycle has 30 days to claim the bicycle and either haul it off site or get it repaired (and labeled) in accordance with Johnson's Bicycle Policy. If the abandoned bicycle is not claimed within 30 days it becomes the property of the Government. The

How similar are two-unit bicycle and motorcycle crashes?

Science.gov (United States)

Haworth, Narelle; Debnath, Ashim Kumar

2013-09-01

This paper explores the similarities and differences between bicycle and motorcycle crashes with other motor vehicles. If similar treatments can be effective for both bicycle and motorcycle crashes, then greater benefits in terms of crash costs saved may be possible for the same investment in treatments. To reduce the biases associated with under-reporting of these crashes to police, property damage and minor injury crashes were excluded. The most common crash type for both bicycles (31.1%) and motorcycles (24.5%) was intersection from adjacent approaches. Drivers of other vehicles were coded most at fault in the majority of two-unit bicycle (57.0%) and motorcycle crashes (62.7%). The crash types, patterns of fault and factors affecting fault were generally similar for bicycle and motorcycle crashes. This confirms the need to combat the factors contributing to failure of other drivers to yield right of way to two-wheelers, and suggest that some of these actions should prove beneficial to the safety of both motorized and non-motorized two-wheelers. In contrast, child bicyclists were more often at fault, particularly in crashes involving a vehicle leaving the driveway or footpath. The greater reporting of violations by riders and drivers in motorcycle crashes also deserves further investigation. Copyright © 2013 Elsevier Ltd. All rights reserved.

A Modified Cellular Automaton Approach for Mixed Bicycle Traffic Flow Modeling

Directory of Open Access Journals (Sweden)

Xiaonian Shan

2015-01-01

Full Text Available Several previous studies have used the Cellular Automaton (CA for the modeling of bicycle traffic flow. However, previous CA models have several limitations, resulting in differences between the simulated and the observed traffic flow features. The primary objective of this study is to propose a modified CA model for simulating the characteristics of mixed bicycle traffic flow. Field data were collected on physically separated bicycle path in Shanghai, China, and were used to calibrate the CA model using the genetic algorithm. Traffic flow features between simulations of several CA models and field observations were compared. The results showed that our modified CA model produced more accurate simulation for the fundamental diagram and the passing events in mixed bicycle traffic flow. Based on our model, the bicycle traffic flow features, including the fundamental diagram, the number of passing events, and the number of lane changes, were analyzed. We also analyzed the traffic flow features with different traffic densities, traffic components on different travel lanes. Results of the study can provide important information for understanding and simulating the operations of mixed bicycle traffic flow.

Prediction of Rowing Ergometer Performance from Functional Anaerobic Power, Strength and Anthropometric Components

Directory of Open Access Journals (Sweden)

Akça Firat

2014-07-01

Full Text Available The aim of this research was to develop different regression models to predict 2000 m rowing ergometer performance with the use of anthropometric, anaerobic and strength variables and to determine how precisely the prediction models constituted by different variables predict performance, when conducted together in the same equation or individually. 38 male collegiate rowers (20.17 ± 1.22 years participated in this study. Anthropometric, strength, 2000 m maximal rowing ergometer and rowing anaerobic power tests were applied. Multiple linear regression procedures were employed in SPSS 16 to constitute five different regression formulas using a different group of variables. The reliability of the regression models was expressed by R2 and the standard error of estimate (SEE. Relationships of all parameters with performance were investigated through Pearson correlation coefficients. The prediction model using a combination of anaerobic, strength and anthropometric variables was found to be the most reliable equation to predict 2000 m rowing ergometer performance (R2 = 0.92, SEE= 3.11 s. Besides, the equation that used rowing anaerobic and strength test results also provided a reliable prediction (R2 = 0.85, SEE= 4.27 s. As a conclusion, it seems clear that physiological determinants which are affected by anaerobic energy pathways should also get involved in the processes and models used for performance prediction and talent identification in rowing.

Associations between a walkability index and bicycle use in Denmark

DEFF Research Database (Denmark)

Madsen, T.; Christiansen, L.; Nielsen, Thomas Alexander Sick

2012-01-01

/day, and important health benefits can accrue from regular commuting cycling. Studies have shown a positive correlation between walkability attributes of neighborhood environments (street connectivity, and use mix, residential density, retail floor area ratio) and cycling. Results from Australia/Belgium show...... associations between measures of walkability and bicycle use for transport and the present study focuses on exploring whether these findings can be applied to a Danish setting where cycling culture differs and bicycle share is much higher (17% of all trips are by bicycle)...

The Measurement of Maximal (Anaerobic Power Output on a Cycle Ergometer: A Critical Review

Directory of Open Access Journals (Sweden)

Tarak Driss

2013-01-01

Full Text Available The interests and limits of the different methods and protocols of maximal (anaerobic power ( assessment are reviewed: single all-out tests versus force-velocity tests, isokinetic ergometers versus friction-loaded ergometers, measure of during the acceleration phase or at peak velocity. The effects of training, athletic practice, diet and pharmacological substances upon the production of maximal mechanical power are not discussed in this review mainly focused on the technical (ergometer, crank length, toe clips, methodological (protocols and biological factors (muscle volume, muscle fiber type, age, gender, growth, temperature, chronobiology and fatigue limiting in cycling. Although the validity of the Wingate test is questionable, a large part of the review is dedicated to this test which is currently the all-out cycling test the most often used. The biomechanical characteristics specific of maximal and high speed cycling, the bioenergetics of the all-out cycling exercises and the influence of biochemical factors (acidosis and alkalosis, phosphate ions… are recalled at the beginning of the paper. The basic knowledge concerning the consequences of the force-velocity relationship upon power output, the biomechanics of sub-maximal cycling exercises and the study on the force-velocity relationship in cycling by Dickinson in 1928 are presented in Appendices.

Reviving a ghost in the history of technology: the social construction of the recumbent bicycle.

Science.gov (United States)

Ahmed, Hassaan; Qureshi, Omer Masood; Khan, Abid Ali

2015-02-01

Recumbent bicycles have never truly been associated with international cycling. Conventional safety (upright) bicycles have long been at the center of the cycling world, for both sport and transportation. This is despite the fact that recumbent bicycles are faster, more comfortable, and more efficient than the upright bicycles. The aim of this article is to explain the historical and social perspectives that led to the rejection of the recumbent bicycle by utilizing the theory of Social Construction of Technology (SCOT) and Bijker's two power theory, providing a contrast with the adoption of the safety bicycle.

Methods to assess the stability of a bicycle rider system

NARCIS (Netherlands)

Cooke, A.G.; Bulsink, Vera Elisabeth; Beusenberg, Mark; Dubbeldam, Rosemary; Bonnema, Gerrit Maarten; Poelman, Wim; Koopman, Hubertus F.J.M.

2012-01-01

The SOFIE (Intelligent Assisted Bicycles) project wishes to create performance and design guidelines for mechatronic appliances which improve the stability of electric bicycles, so-called intelligent stability assist devices (IAD). To achieve this goal, a stability hypothesis, an advanced

36 CFR 1004.30 - Bicycles.

Science.gov (United States)

2010-07-01

... parking area to bicycle use pursuant to the criteria and procedures of §§ 1001.5 and 1001.7 of this... consistent with the protection of natural, scenic and aesthetic values, safety considerations and management...

Using magnetorheological fluids in an innovative hybrid bicycle damper

International Nuclear Information System (INIS)

Shiao, Y J; Nguyen, T S

2015-01-01

Magnetorheological fluids are capable of changing their viscosity quickly. This can provide good controllability and fast dynamic response. A conventional passive suspension system with air spring or hydraulic damper has simple design and financial benefit for bicycles, but its operation is uncontrollable and non-adaptive. This paper presented a semi-active hybrid bicycle suspension system which combines conventional air spring and a new magnetorheological damping brake together to reduce vibration of a bicycle. A multi-layer magnetorheological brake and linkage mechanism are connected to bike fork to form the adaptive damping part of the innovative hybrid suspension system. The simulation results proved that the semi-active suspension system can reduce bike vibration effectively. (paper)

On-road Bicycle Pavement Markings

Data.gov (United States)

Allegheny County / City of Pittsburgh / Western PA Regional Data Center — A mile by mile breakdown of the on-street bicycle pavement markings installed within the City of Pittsburgh. These include bike lanes, shared lane markings...

The Comprehensive Benefit Evaluation of Take Shared Bicycles as Connecting to Public Transit

Science.gov (United States)

Zhang, J. Y.; Sun, H.; Li, P. F.; Li, C. C.

2017-10-01

Shared bicycles as an important way of connecting public transport, have few literature to evaluate its effectiveness.This paper taking Beijing city as an example, make anevaluationfor the six types of travel combinations which are commonly used by the citizens. The author selects four quantitative indicators: fuel consumption, economic cost, total time spent, and CO2 emission. And two qualitative indicators: degree of comfort and convenience. The relative efficiency of quantitative indicators is obtained by data envelopment analysis (DEA) and fuzzification and then take fuzzy synthetic evaluation with qualitative indicators.It was found that the choice of shared bicycles +subway+ shared bicycles and shared bicycles has good comprehensive benefits in medium distance travel. The findings also suggest that shared bicycles +subway+ shared bicycles is the best choice in the utilitarian trips. The conclusions not only provide suggestions for the travellers to select travel modes, but also can adjust the relevant factors to increase the proportion of green travel.

36 CFR 4.30 - Bicycles.

Science.gov (United States)

2010-07-01

... road or parking area to bicycle use pursuant to the criteria and procedures of §§ 1.5 and 1.7 of this... consistent with the protection of a park area's natural, scenic and aesthetic values, safety considerations...

Getting Bicycles on Trains - Inter-modal Transport Developments in Denmark

DEFF Research Database (Denmark)

Jørgensen, Ulrik; Pedersen, Bjørn Brix

2001-01-01

The combined use of bicycles and trains has been favored in contemporary public transport policies in Denmark. Although bicycling has played a major role in Danish personal transportation in more than hundred years, the attitude from public transport authorities towards supporting bicyclists has ...... varied quite a lot....

Modular mechatronic system for stationary bicycles interfaced with virtual environment for rehabilitation.

Science.gov (United States)

Ranky, Richard G; Sivak, Mark L; Lewis, Jeffrey A; Gade, Venkata K; Deutsch, Judith E; Mavroidis, Constantinos

2014-06-05

Cycling has been used in the rehabilitation of individuals with both chronic and post-surgical conditions. Among the challenges with implementing bicycling for rehabilitation is the recruitment of both extremities, in particular when one is weaker or less coordinated. Feedback embedded in virtual reality (VR) augmented cycling may serve to address the requirement for efficacious cycling; specifically recruitment of both extremities and exercising at a high intensity. In this paper a mechatronic rehabilitation bicycling system with an interactive virtual environment, called Virtual Reality Augmented Cycling Kit (VRACK), is presented. Novel hardware components embedded with sensors were implemented on a stationary exercise bicycle to monitor physiological and biomechanical parameters of participants while immersing them in an augmented reality simulation providing the user with visual, auditory and haptic feedback. This modular and adaptable system attaches to commercially-available stationary bicycle systems and interfaces with a personal computer for simulation and data acquisition processes. The complete bicycle system includes: a) handle bars based on hydraulic pressure sensors; b) pedals that monitor pedal kinematics with an inertial measurement unit (IMU) and forces on the pedals while providing vibratory feedback; c) off the shelf electronics to monitor heart rate and d) customized software for rehabilitation. Bench testing for the handle and pedal systems is presented for calibration of the sensors detecting force and angle. The modular mechatronic kit for exercise bicycles was tested in bench testing and human tests. Bench tests performed on the sensorized handle bars and the instrumented pedals validated the measurement accuracy of these components. Rider tests with the VRACK system focused on the pedal system and successfully monitored kinetic and kinematic parameters of the rider's lower extremities. The VRACK system, a virtual reality mechatronic bicycle

Modular mechatronic system for stationary bicycles interfaced with virtual environment for rehabilitation

Science.gov (United States)

2014-01-01

Background Cycling has been used in the rehabilitation of individuals with both chronic and post-surgical conditions. Among the challenges with implementing bicycling for rehabilitation is the recruitment of both extremities, in particular when one is weaker or less coordinated. Feedback embedded in virtual reality (VR) augmented cycling may serve to address the requirement for efficacious cycling; specifically recruitment of both extremities and exercising at a high intensity. Methods In this paper a mechatronic rehabilitation bicycling system with an interactive virtual environment, called Virtual Reality Augmented Cycling Kit (VRACK), is presented. Novel hardware components embedded with sensors were implemented on a stationary exercise bicycle to monitor physiological and biomechanical parameters of participants while immersing them in an augmented reality simulation providing the user with visual, auditory and haptic feedback. This modular and adaptable system attaches to commercially-available stationary bicycle systems and interfaces with a personal computer for simulation and data acquisition processes. The complete bicycle system includes: a) handle bars based on hydraulic pressure sensors; b) pedals that monitor pedal kinematics with an inertial measurement unit (IMU) and forces on the pedals while providing vibratory feedback; c) off the shelf electronics to monitor heart rate and d) customized software for rehabilitation. Bench testing for the handle and pedal systems is presented for calibration of the sensors detecting force and angle. Results The modular mechatronic kit for exercise bicycles was tested in bench testing and human tests. Bench tests performed on the sensorized handle bars and the instrumented pedals validated the measurement accuracy of these components. Rider tests with the VRACK system focused on the pedal system and successfully monitored kinetic and kinematic parameters of the rider’s lower extremities. Conclusions The VRACK

Free Use of Bicycles at CERN

CERN Multimedia

2000-01-01

Imagine you have just arrived at CERN. You are from Russia or Japan and have no car but you do need to get around and do not like depending on public transport. What do you do? You go to the EP Service Point (Building 124) and meet Boris Cabaud to get a CERN bicycle. Use of the bicycle is free but you have to fill in an application form which needs to be signed by your Group or Division Secretary. Then the application is filled in, you are put on the waiting list and it might take you from one to four weeks to get your bike depending on the season. “Normally the bikes are only for Users in the EP division as they are paid for by the EP budget,” says Boris, “but some other divisions have made arrangements to cover the costs.” Boris takes care of 350 bicycles at present. Each bike can be lent for maximum one year. During the winter the bikes can be stored in building 301 as it is difficult to ride them in the snow. If a bike is broken or lost all costs will be billed to the group or team account of the bo...

Bicycle-bus conflict area study.

Science.gov (United States)

2009-11-01

Increasing bicycle use and bus ridership are both desirable policy goals : from a sustainability standpoint, but on city streets these two modes of : transport are often in conflict. While occupying opposite ends of the size : and weight spectrum, th...

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

Directory of Open Access Journals (Sweden)

Sabitha Eunice Regima

2015-06-01

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

The Bicycle Compatibility Index : a level of service concept, implementation manual

Science.gov (United States)

1998-11-01

Currently, no methodology is widely accepted by engineers, planners, or bicycle coordinators that will allow them to determine how compatible a roadway is for allowing efficient operation of both bicycles and motor vehicles. Determining how existing ...

Environmental Risk Factors influencing Bicycle Theft: A Spatial Analysis in London, UK.

Directory of Open Access Journals (Sweden)

Lucy Waruguru Mburu

Full Text Available Urban authorities are continuously drawing up policies to promote cycling among commuters. However, these initiatives are counterproductive for the targeted objectives because they increase opportunities for bicycle theft. This paper explores Inner London as a case study to address place-specific risk factors for bicycle theft at the street-segment level while controlling for seasonal variation. The presence of certain public amenities (e.g., bicycle stands, railway stations, pawnshops was evaluated against locations of bicycle theft between 2013 and 2016 and risk effects were estimated using negative binomial regression models. Results showed that a greater level of risk stemmed from land-use facilities than from area-based socioeconomic status. The presence of facilities such as train stations, vacant houses, pawnbrokers and payday lenders increased bicycle theft, but no evidence was found that linked police stations with crime levels. The findings have significant implications for urban crime prevention with respect to non-residential land use.

Environmental Risk Factors influencing Bicycle Theft: A Spatial Analysis in London, UK.

Science.gov (United States)

Mburu, Lucy Waruguru; Helbich, Marco

2016-01-01

Urban authorities are continuously drawing up policies to promote cycling among commuters. However, these initiatives are counterproductive for the targeted objectives because they increase opportunities for bicycle theft. This paper explores Inner London as a case study to address place-specific risk factors for bicycle theft at the street-segment level while controlling for seasonal variation. The presence of certain public amenities (e.g., bicycle stands, railway stations, pawnshops) was evaluated against locations of bicycle theft between 2013 and 2016 and risk effects were estimated using negative binomial regression models. Results showed that a greater level of risk stemmed from land-use facilities than from area-based socioeconomic status. The presence of facilities such as train stations, vacant houses, pawnbrokers and payday lenders increased bicycle theft, but no evidence was found that linked police stations with crime levels. The findings have significant implications for urban crime prevention with respect to non-residential land use.

Costs and benefits of bicycling investments in Portland, Oregon.

Science.gov (United States)

Gotschi, Thomas

2011-01-01

Promoting bicycling has great potential to increase overall physical activity; however, significant uncertainty exists with regard to the amount and effectiveness of investment needed for infrastructure. The objective of this study is to assess how costs of Portland's past and planned investments in bicycling relate to health and other benefits. Costs of investment plans are compared with 2 types of monetized health benefits, health care cost savings and value of statistical life savings. Levels of bicycling are estimated using past trends, future mode share goals, and a traffic demand model. By 2040, investments in the range of $138 to $605 million will result in health care cost savings of $388 to $594 million, fuel savings of $143 to $218 million, and savings in value of statistical lives of $7 to $12 billion. The benefit-cost ratios for health care and fuel savings are between 3.8 and 1.2 to 1, and an order of magnitude larger when value of statistical lives is used. This first of its kind cost-benefit analysis of investments in bicycling in a US city shows that such efforts are cost-effective, even when only a limited selection of benefits is considered.

Bicycling-related accidents and factors contributing to injury

Energy Technology Data Exchange (ETDEWEB)

Gonzalez Perez, L.M.; Wideberg, J.; Gonzalez Perez-Somarriba, B.

2016-07-01

Objective: This study was conducted to find the epidemiological characteristics of bicycling-related maxillofacial fractures in a defined population, and identify factors contributing to injury. Methodology: A prospective study was carried out involving patients presenting with maxillofacial fractures sustained in bicycling-related accidents. Results: Between 908 of all cycling accidents attending for medical treatment, 122 patients (13% of all cycling accidents) were admitted with facial fractures between 2007 and 2014. Male and female ratio was 2.6:1, and the mean age was 29.4 years (standard deviation: 12.8, range: 12-79 years). Causes of injury included collisions (63%) and accidental falls (37%). The fracture patterns seen were mandibular (49%), zygomatic (32%), orbital (13%), nasal (7%), maxillary (2%), and frontal (2%). Condylar fractures were the most common of the mandibular fractures (63%). The most frequently observed concomitant lesions were orthopedic injuries. Conclusions: Bicycling-related maxillofacial injuries are common and therefore important to identify in order to design a sustainable transport system and for units that provide assistance to traffic accident victims. Missed diagnosis or delayed treatment can lead to facial deformities and functional problems. Wearing protective helmets and the improvement of the helmets design is one aspect that would be of interest for the prevention of injuries. Keywords: Cycling; bicycle-related trauma; maxillofacial fractures; risk factors; helmets. (Author)

Daily Bicycling in Older Adults May Be Effective to Reduce Fall Risks - A Case Control Study.

Science.gov (United States)

Batcir, Shani; Melzer, Itshak

2018-01-18

Older adults gain many health benefits from riding bicycles regularly. We aimed to explore whether older persons who ride bicycles regularly have better balance than controls. Balance control and voluntary stepping were assessed in 20 older adults aged 65 to 85 who live in an agricultural community village who regularly ride bicycles (BR), and 30 age- and gender-matched non-bicycle riders (NBR). Self-reported function and fear of fall were also assessed. Bicycle riders showed significantly better balance, faster voluntary stepping, and better self-reported advanced lower extremity function compared with NBR. The results might suggest that bicycling regularly preserves balance control and speed of voluntary stepping in older adults because bicycling might maintain specific balance coordination patterns. The results should be treated with caution since BR were older adults who selected an active life style (i.e., bicycling as well as living in an agricultural village) that may bias the results.

Bicycle ergometer versus treadmill on balance and gait parameters ...

African Journals Online (AJOL)

Background and purpose: Children with hemophilia often bleed inside the joints and muscles, which may impair postural adjustments. These postural adjustments are necessary to control gait and postural balance during daily activities. The inability to quickly recover postural balance could elevate the risk of bleeding.

Bicycle ergometer versus treadmill on balance and gait parameters ...

African Journals Online (AJOL)

Rasha A. Mohamed

2014-12-01

Dec 1, 2014 ... Department of Physical Therapy for Disturbance of Growth and Development in Children and its ... in blood, the disorders may be classified as severe (<1% of ... joints (knees, elbows, and ankles) because these joints have.

Evaluating the Interference of Bicycle Traffic on Vehicle Operation on Urban Streets with Bike Lanes

Directory of Open Access Journals (Sweden)

Ziyuan Pu

2017-01-01

Full Text Available Many urban streets are designed with on-street bike lanes to provide right-of-way for bicycle traffic. However, when bicycle flow is large, extensive passing maneuvers could occupy vehicle lanes and thus cause interferences to vehicle traffic. The primary objective of this study is to evaluate how bicycle traffic affects vehicle operation on urban streets with bike lanes. Data were collected on six street segments in Nanjing, China. The cumulative curves were constructed to extract traffic flow information including individual bicycle and vehicle speeds and aggregated traffic parameters such as flow and density. The results showed that as bicycle density on bike lanes continuously increases faster bicycles may run into vehicle lanes causing considerable reductions in vehicle speeds. A generalized linear model was estimated to predict the vehicle delay. Results showed that vehicle delay increases as bicycle flow and vehicle flow increase. Number of vehicle lanes and width of bike lane also have significant impact on vehicle delay. Findings of the study are helpful to regions around the world in bike infrastructure design in order to improve operations of both bicycles and vehicles.

Chest Traumas due to Bicycle accident in Childhood

Directory of Open Access Journals (Sweden)

Ufuk Cobanoglu

2011-09-01

Full Text Available Aim:Childhood injuries are the leading cause of death in children and result in significant healthcare utilization. Trauma is the second most common cause of mortality in children aged 1-4 years and leading cause of death in children older than 4 years. Thoracic injury is the second most leading cause of death in traumatized children. Multisystemic injury is found in more than 50% of children with thoracic injuries most of which are secondary to blunt traumas. We planned this study to evaluate thorax trauma cases secondary to bicycle driving in childhood and to draw attention to the importance of the regulation of traffic rules, the education of bicycle drivers.Material and Methods:  A retrospective evaluation was performed in 17 pediatric patients admitted to the Department of Thoracic Surgery during 2006-2010 with a diagnosis of chest trauma due to bicycle driving. For every patient, a pediatric trauma score (PTS was calculated. Descriptive statistics were performed for PTS. Results; Eleven (64.70% cases were injured due to the tricycle accidents and six cases 6 (35.29% were injured due to the two-wheeled bicycle accidents. The most frequent thoracic pathologies included pulmonary contusion (41.2% and chest wall contusion (29.41%. Extrathoracic injuries were seen in 35.29%, the extremities (17.64% and abdomino pelvic (11.76% being the most commonly involved. Treatment consisted of symptomatic treatment in 12 patients (70.58%, tube thoracostomy in 2 patients (11.76%, and thoracotomy in 1 patient (5.9%. The morbidity was seen in 3 patients (17.64%. The mortality rate was 5.9% (n:1. The mean PTS of the cases who had additional system injuries were significantly worse than the cases who had isolated chest traumas Conclusions: The pediatric thorax has a greater cartilage content and incomplete ossification of the ribs. Due to the pliability of the pediatric rib cage and mediastinal mobility, significant intrathoracic injury may exist in the

Predicting Public Bicycle Adoption Using the Technology Acceptance Model

Directory of Open Access Journals (Sweden)

Benjamin T. Hazen

2015-10-01

Full Text Available Bicycle sharing programs provide a sustainable mode of urban transportation. Although cities across the globe have developed these systems for their citizens and visitors, usage rates are not as high as anticipated. This research uses the technology acceptance model as the basis to understand one’s intention to adopt bicycle sharing programs. Using survey data derived from 421 participants in Beijing, China, the proposed covariance-based structural equation model consisting of perceived quality, perceived convenience, and perceived value is found to predict 50.5% of the variance in adoption intention. The findings of this research contribute to theory and practice in the burgeoning literature on public bicycle systems and sustainable urban transportation by offering a theoretical lens through which to consider system adoption, and providing information to practitioners as to what factors might contribute most to adoption.

The use of bicycle workstations to increase physical activity in secondary classrooms

Directory of Open Access Journals (Sweden)

Alicia Fedewa

2017-11-01

Full Text Available Background To date, the majority of interventions have implemented classroom-based physical activity (PA at the elementary level; however, there is both the potential and need to explore student outcomes at high-school level as well, given that very few studies have incorporated classroom-based PA interventions for adolescents. One exception has been the use of bicycle workstations within secondary classrooms. Using bicycle workstations in lieu of traditional chairs in a high school setting shows promise for enhancing adolescents’ physical activity during the school day. Participants and procedure The present study explored the effects of integrating bicycle workstations into a secondary classroom setting for four months in a sample of 115 adolescents using an A-B-A-B withdrawal design. The study took place in one Advanced Placement English classroom across five groups of students. Physical activity outcomes included average heart rate, and caloric expenditure. Behavioural outcomes included percentage of on-task/off-task behaviour and number of teacher prompts in redirecting off-task behaviour. Feasibility and acceptability data of using the bicycle workstations were also collected. Results Findings showed significant improvements in physical activity as measured by heart rate and caloric expenditure, although heart rate percentage remained in the low intensity range when students were on the bicycle workstations. No effects were found on students’ on-task behaviour when using the bicycle workstations. Overall, students found the bikes acceptable to use but noted disadvantages of them as well. Conclusions Using bicycle workstations in high-school settings appears promising for enhancing low-intensity physical activity among adolescents. The limitations of the present study and implications for physical activity interventions in secondary schools are discussed.

Revealed Preference Methods for Studying Bicycle Route Choice—A Systematic Review

Directory of Open Access Journals (Sweden)

Ray Pritchard

2018-03-01

Full Text Available One fundamental aspect of promoting utilitarian bicycle use involves making modifications to the built environment to improve the safety, efficiency and enjoyability of cycling. Revealed preference data on bicycle route choice can assist greatly in understanding the actual behaviour of a highly heterogeneous group of users, which in turn assists the prioritisation of infrastructure or other built environment initiatives. This systematic review seeks to compare the relative strengths and weaknesses of the empirical approaches for evaluating whole journey route choices of bicyclists. Two electronic databases were systematically searched for a selection of keywords pertaining to bicycle and route choice. In total seven families of methods are identified: GPS devices, smartphone applications, crowdsourcing, participant-recalled routes, accompanied journeys, egocentric cameras and virtual reality. The study illustrates a trade-off in the quality of data obtainable and the average number of participants. Future additional methods could include dockless bikeshare, multiple camera solutions using computer vision and immersive bicycle simulator environments.

An Analyses of Bicycle Accidents in Ankara: Analyses of 5 Years

Directory of Open Access Journals (Sweden)

Muhittin Yilmaz

2014-12-01

Full Text Available Aim: Bicycles are used for transportation, exercise and recreation. In this study we aimed to investigate the epidemiological, clinical and economic aspects of bicycle injuries. Material and Method: We included in the study who admitted to the Emergency Department with a bicycle accident between January 2008 and July 2012. Patient age and sex, accident pattern, presence of personal protective measures, injured body part, Glasgow Coma Scale (GCS score, Revised Trauma Score (RTS, radiological findings, requested consultations, duration of hospital stay, season of injury, and average cost rates were recorded. The study population was divided into 2 age groups as 0-14 years and over 14 years. Results: A patients were 238 (81.2% male and their mean age was 31.5±14.1 years. Fifty-five (18.8% patients were female and their mean age was 34.5±15.9 years. Males had significantly higher rate of bicycle injury (p

Investigation of Bicycle Travel Time Estimation Using Bluetooth Sensors for Low Sampling Rates

Directory of Open Access Journals (Sweden)

Zhenyu Mei

2014-10-01

Full Text Available Filtering the data for bicycle travel time using Bluetooth sensors is crucial to the estimation of link travel times on a corridor. The current paper describes an adaptive filtering algorithm for estimating bicycle travel times using Bluetooth data, with consideration of low sampling rates. The data for bicycle travel time using Bluetooth sensors has two characteristics. First, the bicycle flow contains stable and unstable conditions. Second, the collected data have low sampling rates (less than 1%. To avoid erroneous inference, filters are introduced to “purify” multiple time series. The valid data are identified within a dynamically varying validity window with the use of a robust data-filtering procedure. The size of the validity window varies based on the number of preceding sampling intervals without a Bluetooth record. Applications of the proposed algorithm to the dataset from Genshan East Road and Moganshan Road in Hangzhou demonstrate its ability to track typical variations in bicycle travel time efficiently, while suppressing high frequency noise signals.

Interventions in Bicycle Infrastructure, Lessons from Dutch and Danish Cases

DEFF Research Database (Denmark)

van Goeverden, K.; Nielsen, Thomas Alexander Sick; Harder, Henrik

2015-01-01

of interventions in bicycle infrastructure on travel choices, safety, design appreciation, and other factors. These clarify under which conditions certain measures are effective or not and inform about the effectiveness of improving a single route versus upgrading a whole network. The information from the studies...... to be still generally valid. In addition to studies that traditionally focus on dedicated bicycle infrastructure, two cases of shared space are discussed, a rather new type of intervention that assumes mixed use of infrastructure. One case is from Denmark, the other from the Netherlands. The paper will so...... uncover the valuable results of the possibly largest evaluations of interventions in bicycle infrastructure ever made, verify these by examining more recent studies, and contribute to the discussion of shared space....

Pulmonary O2 uptake on-kinetics in endurance- and sprint-trained master athletes.

Science.gov (United States)

Berger, N J A; Rittweger, J; Kwiet, A; Michaelis, I; Williams, A G; Tolfrey, K; Jones, A M

2006-12-01

The purpose of this study was to characterise the VO2 kinetic response to moderate intensity cycle exercise in endurance-trained (END) and sprint or power-trained (SPR) track and field master athletes ranging in age from 45 to 85 years. We hypothesised that the time constant (tau) describing the Phase II VO2 on-response would be smaller in the END compared to the SPR athletes, and that the tau would become greater with increasing age in both groups. Eighty-four master athletes who were competing at either the British or European Veteran Athletics Championships acted as subjects, and were classified as either END (800 m - marathon; n = 41), or SPR (100 - 400 m and field events; n = 43) specialists. Subjects completed two 6 minute "step" transitions to a work rate of moderate intensity on a cycle ergometer and pulmonary gas exchange was measured breath-by-breath. Analysis of variance revealed that SPR athletes had slower VO2 on-kinetics (i.e., greater tau) compared to END athletes at each of the age groups studied: 46 - 55 yrs (END: 25 +/- 6 vs. SPR: 36 +/- 9 s; p kinetics became slower with advancing age in the SPR athletes (p kinetics in SPR compared to END master athletes is consistent both with differences in physiology (e.g., muscle fibre type, oxidative/glycolytic capacity) and training between these specialist athletes. Master END athletes have similar tau values to their younger counterparts (approximately 25 s) suggesting that participation in endurance exercise training limits the slowing of VO2 on-kinetics with age in this population.

Low-stress bicycling and network connectivity.

Science.gov (United States)

2012-05-01

For a bicycling network to attract the widest possible segment of the population, its most fundamental attribute should be low-stress connectivity, that is, providing routes between peoples origins and destinations that do not require cyclists to ...

The unexpected stable market share of the bicycle in The Netherlands

NARCIS (Netherlands)

Van Goeverden, C.D.; Van Arem, B.; Godefrooij, T.

2013-01-01

In the Netherlands, the share of the bicycle as the main mode in all person trips has been highly constant in the past three decades (about 27%). A constant share is remarkable because a number of developments in this period were unfavourable for bicycle use, like ageing of the population, growing

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

Directory of Open Access Journals (Sweden)

Marius Schild

2016-01-01

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

Bicycle Trains, Cycling, and Physical Activity: A Pilot Cluster RCT.

Science.gov (United States)

Mendoza, Jason A; Haaland, Wren; Jacobs, Maya; Abbey-Lambertz, Mark; Miller, Josh; Salls, Deb; Todd, Winifred; Madding, Rachel; Ellis, Katherine; Kerr, Jacqueline

2017-10-01

Increasing children's cycling to school and physical activity are national health goals. The objective was to conduct an RCT of a bicycle train program to assess impact on students' school travel mode and moderate-to-vigorous physical activity (MVPA). Pilot cluster RCT with randomization at the school level and N=54 participants. Fourth-fifth graders from four public schools serving low-income families in Seattle, WA in 2014 with analyses in 2015-2016. All participants were provided and fitted with bicycles, safety equipment (helmets, locks, and lights), and a 2- to 3-hour bicycle safety course. The intervention was a bicycle train offered daily (i.e., students volunteered to cycle with study staff to and from school). Time 1 assessments occurred prior to randomization. Time 2 assessments occurred after 3-5 weeks of the intervention (i.e., during Weeks 4-6 of the intervention period). The primary outcome was the percentage of daily commutes to school by cycling measured by validated survey. MVPA, measured by accelerometry and GPS units and processed by machine learning algorithms, was a secondary outcome. For two separate adjusted repeated measures linear mixed effects models in which students (N=54) were nested within schools (N=4), intervention participants had: (1) an absolute increase in mean percentage of daily commutes by cycling of 44.9%, (95% CI=26.8, 63.0) and (2) an increase in mean MVPA of 21.6 minutes/day, (95% CI=8.7, 34.6) from Time 1 to Time 2 compared with controls. A pilot bicycle train intervention increased cycling to school and daily MVPA in the short term among diverse, inner-city elementary school students. The bicycle train intervention appears promising and warrants further experimental trials among large, diverse samples with longer follow-up. This study is registered at www.clinicaltrials.gov NCT02006186. Copyright © 2017 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

Predicting Free Flow Speed and Crash Risk of Bicycle Traffic Flow Using Artificial Neural Network Models

Directory of Open Access Journals (Sweden)

Cheng Xu

2015-01-01

Full Text Available Free flow speed is a fundamental measure of traffic performance and has been found to affect the severity of crash risk. However, the previous studies lack analysis and modelling of impact factors on bicycles’ free flow speed. The main focus of this study is to develop multilayer back propagation artificial neural network (BPANN models for the prediction of free flow speed and crash risk on the separated bicycle path. Four different models with considering different combinations of input variables (e.g., path width, traffic condition, bicycle type, and cyclists’ characteristics were developed. 459 field data samples were collected from eleven bicycle paths in Hangzhou, China, and 70% of total samples were used for training, 15% for validation, and 15% for testing. The results show that considering the input variables of bicycle types and characteristics of cyclists will effectively improve the accuracy of the prediction models. Meanwhile, the parameters of bicycle types have more significant effect on predicting free flow speed of bicycle compared to those of cyclists’ characteristics. The findings could contribute for evaluation, planning, and management of bicycle safety.

DEVELOPMENT OF AN ELECTRIC BICYCLE FOR A SHARING SYSTEM IN PRAGUE

Directory of Open Access Journals (Sweden)

William Deleenheer

2017-12-01

Full Text Available By means of a development of an e-bike sharing system the Electromobility Project wants to provide an alternative way of comfortable transportation for students and staff of the CTU, primarily to commute between different campuses. The research for this project contains at least three different fields of study, namely electric vehicle and docking station development, intelligent transport systems and management and economics of transportation and telecommunication. After briefly stating general requirements for the sharing system, this paper focuses on the development of the electric bicycle. First an ideal bike design is defined. Then necessary motor power and battery capacity are calculated by estimating characteristics of cycling in Prague. A prototype was developed by converting a normal bicycle to an electric bicycle. Being equipped with devices for e-bike monitoring, controlling and data recording for a post trip analysis, this prototype is also intended to have an educational value for future students in the project. Results consist of an electrical bicycle configuration that matches the requirements and a sketch of an ideal e-bike for this project.

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

DEFF Research Database (Denmark)

Aagaard, Per; Andersen, Jesper L

2010-01-01

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

Bicycle Safety: Sport Education Style

Science.gov (United States)

Sinelnikov, Oleg A.; Hastie, Peter A.; Cole, Amy; Schneulle, Deanna

2005-01-01

Although the benefits of regular physical activity are well-documented and very well known, Americans are still becoming more sedentary and obese. As some experts envision the potential of nonmotorized transport in the future, especially in urban settings, it is not surprising that diverse groups view walking and bicycling as a solution to an…

Improvement of Freezing of Gait in Patients with Parkinson's Disease by Imagining Bicycling

Directory of Open Access Journals (Sweden)

Akio Kikuchi

2014-03-01

Full Text Available Freezing of gait (FOG is one of the factors that reduce the quality of life in patients with Parkinson's disease (PD. Imagining bicycling before gait start provided improvement in FOG in 2 PD patients. Imagining and mimicking bicycling after the initiation of gait allowed the rhythmic gait to continue without interruption. We suggest that imagining and mimicking bicycling, which are nonexternal cues, could serve as a helpful therapeutic approach for the intractable freezing and interruption of gait of PD patients.

Determining the Optimal Layout Design for Public Bicycle System within the Attractive Scope of a Metro Station

Directory of Open Access Journals (Sweden)

Jingxu Chen

2015-01-01

Full Text Available Public bicycle acts as a seamless feeder mode in combination with the citywide public transit, as well as a competitor for the inner-city short trips. The primary objective of this study is to address the layout planning of public bicycle system within the attracted scope of a metro station. Based on the land use function, population, and bicycle mode share, bicycle rental stations are divided into three types, namely, the metro station, district station, and resident station, and later the quantity of bicycle facilities in each rental station is estimated. Then, the service stations are selected from these bicycle rental stations to provide the service of periodical bicycle redistribution. An improved immune algorithm is proposed to determine the number and locations of service stations and the optimal route options for the implement of redistributing strategy. Finally, a case study of Nanjing Tianyin Road metro station is conducted to illustrate the proposed model and clarify some of its implementation details.

Teaching children about bicycle safety: an evaluation of the New Jersey Bike School program.

Science.gov (United States)

Lachapelle, Ugo; Noland, Robert B; Von Hagen, Leigh Ann

2013-03-01

There are multiple health and environmental benefits associated with increasing bicycling among children. However, the use of bicycles is also associated with severe injuries and fatalities. In order to reduce bicycle crashes, a bicycling education program was implemented in selected New Jersey schools and summer camps as part of the New Jersey Safe Routes to School Program. Using a convenience sample of participants to the program, an opportunistic study was designed to evaluate the effectiveness of two bicycle education programs, the first a more-structured program delivered in a school setting, with no on-road component, and the other a less structured program delivered in a summer camp setting that included an on-road component. Tests administered before and after training were designed to assess knowledge acquired during the training. Questions assessed children's existing knowledge of helmet use and other equipment, bicycle safety, as well as their ability to discriminate hazards and understand rules of the road. Participating children (n=699) also completed a travel survey that assessed their bicycling behavior and their perception of safety issues. Response to individual questions, overall pre- and post-training test scores, and changes in test scores were compared using comparison of proportion, t-tests, and ordinary least-squares (OLS) regression. Improvements between the pre-training and post-training test are apparent from the frequency distribution of test results and from t-tests. Both summer camps and school-based programs recorded similar improvements in test results. Children who bicycled with their parents scored higher on the pre-training test but did not improve as much on the post-training test. Without evaluating long-term changes in behavior, it is difficult to ascertain how successful the program is on eventual behavioral and safety outcomes. Copyright © 2012 Elsevier Ltd. All rights reserved.

EP BICYCLE POOL - VIGNETTES 2002

CERN Multimedia

EP-SMI Help Desk

2002-01-01

The vignettes (insurance certificates) for 2002 become obligatory from 1 June. If you have a bicycle from the EP Pool, please bring it to the EP-SMI Help Desk (Building 124) on any working day up to 31 May between 8h.30 - 12h.00 or 13h.30 - 17h.30. EP-SMI Help Desk

Biomechanical Evaluation of an Electric Power-Assisted Bicycle by a Musculoskeletal Model

Science.gov (United States)

Takehara, Shoichiro; Murakami, Musashi; Hase, Kazunori

In this study, we construct an evaluation system for the muscular activity of the lower limbs when a human pedals an electric power-assisted bicycle. The evaluation system is composed of an electric power-assisted bicycle, a numerical simulator and a motion capture system. The electric power-assisted bicycle in this study has a pedal with an attached force sensor. The numerical simulator for pedaling motion is a musculoskeletal model of a human. The motion capture system measures the joint angles of the lower limb. We examine the influence of the electric power-assisted force on each muscle of the human trunk and legs. First, an experiment of pedaling motion is performed. Then, the musculoskeletal model is calculated by using the experimental data. We discuss the influence on each muscle by electric power-assist. It is found that the muscular activity is decreased by the electric power-assist bicycle, and the reduction of the muscular force required for pedaling motion was quantitatively shown for every muscle.

Underwater Cycle Ergometry: Power Requirements With and Without Diver Thermal Dress

Science.gov (United States)

2009-01-01

waterproofed Collins Pedal Mate ergometers that are no longer available. A pedal shaft drives the shaft of a hysteresis brake (HB210, Magtrol; Buffalo, NY...NEDU, regular bicycle pedals with toe straps/ over canvas shoes were used in Buffalo (personal 13 communication). The foot cups used at NEDU are

Cardiovascular health benefits of some locally adoptable exercise ...

African Journals Online (AJOL)

... access the much evidence based benefit of exercise on cardiovascular health because they hold the believe that effective exercise can only be done in the organized gymnasium. We compared the cardiovascular effect of riding bicycle ergometer, a commonly used gymnasium equipment with that of jogging and walking ...

A Remote Power Management Strategy for the Solar Energy Powered Bicycle

Directory of Open Access Journals (Sweden)

Chung-Hsing Chao

2011-12-01

Full Text Available In this paper, a solar energy powered bicycle by a wireless sensor network (WSN far-end network monitoring solar energy to transfer the electrical energy storage and the effectiveness analysis is proposed. In order to achieve this goal, an embarked ZigBee by a solar-powered bicycle the far-end wireless network supervisory system is setup. Experimental results prove that our prototype, the solar energy powered bicycle, can manage the solar energy for charging two Lead-Acid batteries pack. As a result, the user by the wireless network in parking period knows the data on the amount of immediate solar radiation, the degree of illumination, the ambient temperature, and electrical energy storage capacity information by the internet interface.

Continuous variable transmission and regenerative braking devices in bicycles utilizing magnetorheological fluids

Science.gov (United States)

Cheung, Wai Ming; Liao, Wei-Hsin

2013-04-01

The use of magnetorheological (MR) fluids in vehicles has been gaining popular recently due to its controllable nature, which gives automotive designers more dimensions of freedom in functional designs. However, not much attention has been paid to apply it to bicycles. This paper is aimed to study the feasibility of applying MR fluids in different dynamic parts of a bicycle such as the transmission and braking systems. MR continuous variable transmission (CVT) and power generator assisted in braking systems were designed and analyzed. Both prototypes were fabricated and tested to evaluate their performances. Experimental results showed that the proposed designs are promising to be used in bicycles.

A multi-modal network approach to model public transport accessibility impacts of bicycle-train integration policies

NARCIS (Netherlands)

Geurs, Karst Teunis; La Paix Puello, Lissy Cesarina; van Weperen, Sander

2016-01-01

In the Netherlands, the bicycle plays an important in station access and, to a lesser extent, in station egress. There is however fairly little knowledge in the potential effects of bicycle-train integration policies. The aim of this paper is to examine the impacts of bicycle-train integration

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

Science.gov (United States)

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

2015-01-01

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

Does pedalling on a recumbent bicycle influence the cyclist’s steering behaviour?

NARCIS (Netherlands)

Boon, K.M.; Klap, P.; Van Lanen, J.A.; Letsoin, G.J.; Jansen, A.J.

2014-01-01

The paper presents the answer to the question how pedalling on a specific recumbent bicycle, such as the VeloX3, influences a cyclist’s ability to steer the bicycle. The research aims to find the correlation between pedalling and the undesired steering movements it creates. To test this assumption a

An Association Rule Based Method to Integrate Metro-Public Bicycle Smart Card Data for Trip Chain Analysis

Directory of Open Access Journals (Sweden)

De Zhao

2018-01-01

Full Text Available Smart card data provide valuable insights and massive samples for enhancing the understanding of transfer behavior between metro and public bicycle. However, smart cards for metro and public bicycle are often issued and managed by independent companies and this results in the same commuter having different identity tags in the metro and public bicycle smart card systems. The primary objective of this study is to develop a data fusion methodology for matching metro and public bicycle smart cards for the same commuter using historical smart card data. A novel method with association rules to match the data derived from the two systems is proposed and validation was performed. The results showed that our proposed method successfully matched 573 pairs of smart cards with an accuracy of 100%. We also validated the association rules method through visualization of individual metro and public bicycle trips. Based on the matched cards, interesting findings of metro-bicycle transfer have been derived, including the spatial pattern of the public bicycle as first/last mile solution as well as the duration of a metro trip chain.

Methodological Considerations on the Relationship Between the 1,500-M Rowing Ergometer Performance and Vertical Jump in National-Level Adolescent Rowers.

Science.gov (United States)

Maciejewski, Hugo; Rahmani, Abderrahmane; Chorin, Frédéric; Lardy, Julien; Samozino, Pierre; Ratel, Sébastien

2018-03-12

The purpose of the present study was to investigate whether three different approaches for evaluating squat jump performance were correlated to rowing ergometer performance in elite adolescent rowers. Fourteen young male competitive rowers (15.3 ± 0.6 years), who took part in the French rowing national championships, performed a 1,500-m all-out rowing ergometer performance (P1500) and a squat jump (SJ) test. The performance in SJ was determined by calculating the jump height (HSJ in cm), a jump index (ISJ = HSJ · body mass · gravity, in J) and the mean power output (PSJ in W) from the Samozino et al.'s method. Furthermore, allometric modelling procedures were used to consider the importance of body mass (BM) in the assessment of HSJ, ISJ and PSJ, and their relationships with between P1500 and jump scores. P1500 was significantly correlated to HSJ (r2 = 0.29, P jump and rowing ergometer performances at the same rate, and that PSJ could be the best correlate of P1500. Therefore, the calculation of power seems to be more relevant than HSJ and ISJ to (i) evaluate jump performance, and (ii) infer the capacity of adolescent rowers to perform 1,500-m all-out rowing ergometer performance, irrespective of their body mass. This could help coaches to improve their training program and potentially identify talented young rowers.

A summary of design, policies and operational characteristics for shared bicycle/bus lanes.

Science.gov (United States)

2012-07-01

This report contains the results of an investigation of the design and operation of shared bicycle/bus lanes in municipalities in the United States and other countries. These lanes are designated for use by public transit buses, bicycles, and usually...

MIT-Skywalker: Evaluating comfort of bicycle/saddle seat.

Science.gov (United States)

Goncalves, Rogerio S; Hamilton, Taya; Daher, Ali R; Hirai, Hiroaki; Krebs, Hermano I

2017-07-01

The MIT-Skywalker is a robotic device developed for the rehabilitation of gait and balance after a neurological injury. This device has been designed based on the concept of a passive walker and provides three distinct training modes: discrete movement, rhythmic movement, and balance training. In this paper, we present our efforts to evaluate the comfort of a bicycle/saddle seat design for the system's novel actuated body weight support device. We employed different bicycle and saddle seats and evaluated comfort using objective and subjective measures. Here we will summarize the results obtained from a study of fifteen healthy subjects and one stroke patient that led to the selection of a saddle seat design for the MIT-Skywalker.

Plasma concentration of high-mobility group box 1 (HMGB1) after 100 drop to vertical jumps and after a 1200-km bicycle race.

Science.gov (United States)

Behringer, M; Kilian, Y; Montag, J; Geesmann, B; Mester, J

2016-01-01

High-mobility group box 1 (HMGB1) has recently been reported to be involved in proinflammation and tissue repair. Therefore, we hypothesized that HMGB1 is released into the bloodstream after eccentric exercises or prolonged endurance activities. Blood samples from 11 participants that performed 100 drop to vertical jumps (DVJ) and from 10 participants that took part in the 1200-km 'Paris-Brest-Paris' bicycle race (PBP) were tested for HMGB1 and creatine kinase (CK) levels. CK increased after both DVJ (pre: 150.6 ± 81.5 U/L; post: 188.8 ± 95.5 U/L 8 h: 790.5 ± 346.4 U/L) and PBP (pre: 81.3 ± 36.4 U/L; post: 725.2 ± 229.5 U/L; 12 h: 535.8 ± 188.6 U/L), indicating membrane damage. However, HMGB1 plasma levels remained below the detection limit (78 pg/mL) of the applied enzyme-linked immunosorbent assay kit for all blood samples analysed. That is, neither high intensity eccentric exercises (DVJ) nor prolonged endurance events (PBP) seemed to affect HMGB1 levels in blood at selected time points.

Gross efficiency and energy expenditure in kayak ergometer exercise.

Science.gov (United States)

Gomes, B B; Mourão, L; Massart, A; Figueiredo, P; Vilas-Boas, J P; Santos, A M C; Fernandes, R J

2012-08-01

We purposed to study energy expenditure, power output and gross efficiency during kayak ergometer exercise in 12 elite sprint kayakers. 6 males (age 24.2±4.8 years, height 180.4±4.8 cm, body mass 79.7±8.5 kg) and 6 females (age 24.3±4.5 years, height 164.5±3.9 cm, body mass 65.4±3.5 kg), performed an incremental intermittent protocol on kayak ergometer with VO2 and blood lactate concentration assessment, a non-linear increase between power output and energy expenditure being observed. Paddling power output, energy expenditure and gross efficiency corresponding to VO2max averaged 199.92±50.41 W, 75.27±6.30 ml.kg - 1.min - 1, and 10.10±1.08%. Male kayakers presented higher VO2max, power output and gross efficiency at the VO2max, and lower heart rate and maximal lactate concentration than females, but no differences were found between genders regarding energy expenditure at VO2max. Aerobic and anaerobic components of energy expenditure evidenced a significant contribution of anaerobic energy sources in sprint kayak performance. Results also suggested the dependence of the gross efficiency on the changes in the amount of the aerobic and anaerobic contributions, at heavy and severe intensities. The inter-individual variance of the relationship between energy expenditure and the corresponding paddling power output revealed a relevant tracking for females (FDγ=0.73±0.06), conversely to the male group (FDγ=0.27±0.08), supporting that some male kayakers are more skilled in some paddling intensities than others. © Georg Thieme Verlag KG Stuttgart · New York.

Bicycling to Work and Primordial Prevention of Cardiovascular Risk

DEFF Research Database (Denmark)

Grøntved, Anders; Koivula, Robert W; Johansson, Ingegerd

2016-01-01

of incident obesity, hypertension, hypertriglyceridemia, and impaired glucose tolerance, comparing individuals who commuted to work by bicycle with those who used passive modes of transportation. We also examined the relationship of change in commuting mode with incidence of these clinical risk factors......% CI 0.74-0.91) compared with participants not cycling to work at both times points or who switched from cycling to other modes of transport during follow-up. CONCLUSIONS: These data suggest that commuting by bicycle to work is an important strategy for primordial prevention of clinical cardiovascular...... risk factors among middle-aged men and women....

Testing of badminton specific endurance

DEFF Research Database (Denmark)

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

2016-01-01

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

Evaluation of the dispersion effect in through movement bicycles at signalized intersection via cellular automata simulation

Science.gov (United States)

Jiang, Hang; Ma, Yongjian; Jiang, Lin; Chen, Guozhou; Wang, Dongwei

2018-05-01

At signalized intersection areas, bicycle traffic presents a dispersion feature which may influence the movements of vehicles during peak period. The primary objective of this study is to simulate the dispersion effect in through-movement bicycle traffic at intersection areas and evaluate its influence on through-movement traffic. A cellular automata (CA) model is developed and validated to simulate the operations of through-movement bicycle traffic departing from two types of intersection approaches. Simulation results show that bicycles benefit from the dispersion effect when they depart from the approach with an exclusive right-turn vehicle lane. But when bicycles travel from the approach with a shared right-turn and through vehicle lane, the dispersion effect will result in friction interference and block interference on through-movement vehicles. Bicycle interferences reduce the vehicle speed and increase the delay of through-movement vehicles. The policy implications in regard to the dispersion effect from two types of approaches are discussed to improve the performance of through-movement traffic operations at signalized intersections.

Comparison of five bicycle facility designs in signalized intersections using traffic conflict studies

DEFF Research Database (Denmark)

Madsen, Tanja Kidholm Osmann; Lahrmann, Harry Spaabæk

2017-01-01

Highlights •Traffic conflict study comparing cyclists’ relative risk for five bicycle layouts. •Watchdog video analysis software applied to reduce video data. •Video analysis software necessary to conduct larger conflict studies. •Recessed bicycle track seems to provide the highest safety level...

Assessing the Bicycle Network in St. Louis: A PlaceBased User-Centered Approach

Directory of Open Access Journals (Sweden)

Bram Boettge

2017-02-01

Full Text Available To transition towards sustainability and increase low-impact transportation, city planners are integrating bicycle infrastructure in urban landscapes. Yet, this infrastructure only promotes cycling according to how well it is sited within a specific city. How to best site bicycle facilities is essential for sustainability planning. We review approaches to assessing and siting new bicycle facilities. Following sustainability science, we argue that active cyclists should be consulted to incorporate users’ site-specific knowledge into bicycle infrastructure assessments. We then pilot an approach that surveys cyclists concerning level of stress along routes ridden in St. Louis, MO, USA. Among the active cyclists surveyed (n = 89, we found stress correlates with speed limit, roadway classification, and number of lanes. Although cyclists surveyed in St. Louis prefer roads with bike lanes over roads with sharrows or no infrastructure, the presence of bicycle infrastructure had no correlation with reported levels of stress. The piloted survey and spatial analytic tool are transferable to other localities. For planners, the maps generated by this participant data approach identify high-stress routes as targets of new infrastructure or information to direct cyclists to safer routes. For bicyclists, the maps generated identify low-stress routes for recreation and commuting.

Traumatic Globe Subluxation and Intracranial Injury Caused by Bicycle Brake Handle

OpenAIRE

Poroy; Cibik; Yazici

2016-01-01

Introduction Penetration of a bicycle brake handle into the orbit is a rare and serious type of trauma. Globe subluxation due to such trauma has not been previously reported. Case Presentation A 10-year-old girl presented after falling from a bicycle, which resulted in the handbrake penetrating her right upper eyelid. On examination, the globe was subluxated anteriorly, there was no light perception, and the pupilla was fixed and ...

Bicycles, transportation sustainability, and quality of life.

Science.gov (United States)

2014-01-01

The research presented in this report focuses on the exploration of a variety of objective and subjective quality of life indicators and approaches for bicycle transportation using a mixed methods approach. The authors have created a conceptual frame...

How bicycle level of traffic stress correlate with reported cyclist accidents injury severities: A geospatial and mixed logit analysis.

Science.gov (United States)

Chen, Chen; Anderson, Jason C; Wang, Haizhong; Wang, Yinhai; Vogt, Rachel; Hernandez, Salvador

2017-11-01

Transportation agencies need efficient methods to determine how to reduce bicycle accidents while promoting cycling activities and prioritizing safety improvement investments. Many studies have used standalone methods, such as level of traffic stress (LTS) and bicycle level of service (BLOS), to better understand bicycle mode share and network connectivity for a region. However, in most cases, other studies rely on crash severity models to explain what variables contribute to the severity of bicycle related crashes. This research uniquely correlates bicycle LTS with reported bicycle crash locations for four cities in New Hampshire through geospatial mapping. LTS measurements and crash locations are compared visually using a GIS framework. Next, a bicycle injury severity model, that incorporates LTS measurements, is created through a mixed logit modeling framework. Results of the visual analysis show some geospatial correlation between higher LTS roads and "Injury" type bicycle crashes. It was determined, statistically, that LTS has an effect on the severity level of bicycle crashes and high LTS can have varying effects on severity outcome. However, it is recommended that further analyses be conducted to better understand the statistical significance and effect of LTS on injury severity. As such, this research will validate the use of LTS as a proxy for safety risk regardless of the recorded bicycle crash history. This research will help identify the clustering patterns of bicycle crashes on high-risk corridors and, therefore, assist with bicycle route planning and policy making. This paper also suggests low-cost countermeasures or treatments that can be implemented to address high-risk areas. Specifically, with the goal of providing safer routes for cyclists, such countermeasures or treatments have the potential to substantially reduce the number of fatalities and severe injuries. Published by Elsevier Ltd.

Association of Sociodemographic and Perceived Environmental Factors with Public Bicycle Use among Taiwanese Urban Adults

Directory of Open Access Journals (Sweden)

Yung Liao

2016-03-01

Full Text Available Background: This study examined the sociodemographic and perceived environmental factors associated with public bicycle use among Taiwanese urban adults. Methods: A random-digit-dialing telephone-based cross-sectional survey was administered to Taiwanese urban adults aged 20–64 years in 2015. Data on sociodemographic variables, perceived environmental factors (for attributes identified in the International Physical Activity Questionnaire-Environmental Module, and public bicycle use were obtained from 1002 adults in three cities. Adjusted logistic regression was used. Results: After adjustment for potential confounders, the results showed that adults aged 20–29 years (odds ratio (OR = 4.42 with a university degree or higher (OR = 2.03 were more likely to use public bicycles. In addition, adults living in Kaohsiung City were less likely to use public bicycles (OR = 0.24. Adults who saw people being active (OR = 1.76; 95% CI: 1.05–2.86 and had positive aesthetic experiences of their environment (OR = 1.69 were more likely to use public bicycles. Conclusions: Our findings suggest that seeing physically active people and positive aesthetic perceptions of the environment are key factors for developing transportation policies and intervention strategies for promoting public bicycle use among Taiwanese urban adults.

Effects of Cycling vs. Running Training on Endurance Performance in Preparation for Inline Speed Skating.

Science.gov (United States)

Stangier, Carolin; Abel, Thomas; Hesse, Clemens; Claen, Stephanie; Mierau, Julia; Hollmann, Wildor; Strüder, Heiko K

2016-06-01

Winter weather conditions restrict regular sport-specific endurance training in inline speed skating. As a result, this study was designed to compare the effects of cycling and running training programs on inline speed skaters' endurance performance. Sixteen (8 men, 8 women) high-level athletes (mean ± SD 24 ± 8 years) were randomly assigned to 1 of 2 groups (running and cycling). Both groups trained twice a week for 8 weeks, one group on a treadmill and the other on a cycle ergometer. Training intensity and duration was individually calculated (maximal fat oxidation: ∼52% of V[Combining Dot Above]O2peak: 500 kcal per session). Before and after the training intervention, all athletes performed an incremental specific (inline speed skating) and 1 nonspecific (cycling or running) step test according to the group affiliation. In addition to blood lactate concentration, oxygen uptake (V[Combining Dot Above]O2), ventilatory equivalent (VE/V[Combining Dot Above]O2), respiratory exchange ratio (RER), and heart rate were measured. The specific posttest revealed significantly increased absolute V[Combining Dot Above]O2peak values (2.9 ± 0.4, 3.4 ± 0.7, p = 0.01) and submaximal V[Combining Dot Above]O2 values (p ≤ 0.01). VE/V[Combining Dot Above]O2 and RER significantly decreased at maximal (46.6 ± 6.6, 38.5 ± 3.4, p = 0.005; 1.1 ± 0.03, 1.0 ± 0.04, p = 0.001) and submaximal intensities (p ≤ 0.04). None of the analysis revealed a significant group effect (p ≥ 0.15). The results indicate that both cycling vs. running exercise at ∼52% of V[Combining Dot Above]O2peak had a positive effect on the athletes' endurance performance. The increased submaximal V[Combining Dot Above]O2 values indicate a reduction in athletes' inline speed skating technique. Therefore, athletes would benefit from a focus on technique training in the subsequent period.

Bicycle-friendly infrastructure planning in Beijing and Copenhagen - between adapting design solutions and learning local planning cultures

DEFF Research Database (Denmark)

Zhao, Chunli; Carstensen, Trine Agervig; Nielsen, Thomas Alexander Sick

2018-01-01

Abstract Cities around the world are constructing bicycle infrastructure to increase cycling. However, identifying efficient design solutions and determining how bicycle infrastructure planning knowledge can be integrated into comprehensive policy remains a challenge. The objective of this paper...... is to shed light on the strengths and weaknesses of current bicycle infrastructure planning in both an experienced city, Copenhagen, and in a less experienced city, Beijing. The paper examines how local design solutions are identified, how efficient they are and to what extent bicycle infrastructure planning...

Hydraulic brake-system for a bicycle

NARCIS (Netherlands)

Van Frankenhuyzen, J.

2007-01-01

The invention relates to a hydraulic brake system for a bicycle which may or may not be provided with an auxiliary motor, comprising a brake disc and brake claws cooperating with the brake disc, as well as fluid-containing channels (4,6) that extend between an operating organ (1) and the brake

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

Electric motor assisted bicycle as an aerobic exercise machine.

Science.gov (United States)

Nagata, T; Okada, S; Makikawa, M

2012-01-01

The goal of this study is to maintain a continuous level of exercise intensity around the aerobic threshold (AT) during riding on an electric motor assisted bicycle using a new control system of electrical motor assistance which uses the efficient pedaling rate of popular bicycles. Five male subjects participated in the experiment, and the oxygen uptake was measured during cycling exercise using this new pedaling rate control system of electrical motor assistance, which could maintain the pedaling rate within a specific range, similar to that in previous type of electrically assisted bicycles. Results showed that this new pedaling rate control system at 65 rpm ensured continuous aerobic exercise intensity around the AT in two subjects, and this intensity level was higher than that observed in previous type. However, certain subjects were unable to maintain the expected exercise intensity because of their particular cycling preferences such as the pedaling rate. It is necessary to adjust the specific pedaling rate range of the electrical motor assist control according to the preferred pedaling rate, so that this system becomes applicable to anyone who want continuous aerobic exercise.

What do we know about bicycle helmets?

NARCIS (Netherlands)

Bogerd, C.P. Halldin, P. Houtenbos, M. Otte, D. Rossi, R.M. Walker, L. Willinger, R. & Shinar, D.

2012-01-01

Cycling is an excellent sustainable alternative to driving for many journeys. But cyclists have fewer safety options than car-users, with a helmet being the main safety device that is available. However, there are indications that increasing bicycle helmet usage through legislation causes

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

Science.gov (United States)

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

2013-03-01

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

What Factors Explain Bicycling and Walking for Commuting by ELSA-Brasil Participants?

Science.gov (United States)

de Matos, Sheila Maria Alvim; Pitanga, Francisco José Gondim; Almeida, Maria da Conceição C; Queiroz, Ciro Oliveira; Dos Santos, Clarice Alves; de Almeida, Rogerio Tosta; da Silva, Ianne Tayrine Martins; Griep, Rosane Harter; Amorim, Leila Denise Alves Ferreira; Patrão, Ana Luísa; Aquino, Estela M L

2018-03-01

To analyze the factors associated with commuting by bicycling and walking in adult participants from ELSA-Brasil (Longitudinal Study of Adult Health). Cross-sectional. Six teaching/research institutions throughout Brazil. A total of 15 105 civil servants. Commuting by bicycling and walking was analyzed using the long-form International Physical Activity Questionnaire. A hierarchical model containing possible factors associated with commuting by bicycling and walking was constructed. Crude and adjusted odds ratios were calculated using multinomial logistic regression. Considering the 2 forms of commuting, 66% of the participants were being considered inactive or insufficiently active. In women, being "heavier," feeling unsafe practicing physical activity, and being a former smoker were factors negatively associated with commuting by bicycling and walking. In men, active commuting was less common among those who were overweight or had abdominal obesity, those with a negative perception of safety, and those reporting that there was nowhere suitable in the neighborhood to practice physical activity. Obesity and negative perceptions in the neighborhood are associated with inactive or insufficiently active commuting. The relevance of this finding for public health is reinforce developing policies aimed at promoting health in Brazil and in other countries with similar characteristics.

How the Netherlands became a bicycle nation : users, firms and intermediaries, 1860-1940

NARCIS (Netherlands)

Tjong Tjin Tai, S.E.; Veraart, F.C.A.; Davids, M.

2015-01-01

In 1925, the Netherlands was a country of cyclists and cycle producers, as all classes cycled and almost all cycles were produced domestically. The bicycle was not a Dutch invention and the country had an open economy, and this raises the question ‘how did the Netherlands become a bicycle nation?’

Biking for Health: Results of a Pilot Randomized Controlled Trial Examining the Impact of a Bicycling Intervention on Lower-Income Adults.

Science.gov (United States)

Bernstein, Rebecca; Schneider, Robert; Welch, Whitney; Dressel, Anne; DeNomie, Melissa; Kusch, Jennifer; Sosa, Mirtha

2017-08-01

This pilot study tested the efficacy of a bicycling intervention targeting inactive, low-income, overweight adults on reducing perceived barriers to bicycling, increasing physical activity, and improving health. A nonblinded 2-site randomized controlled trial was conducted in Milwaukee, Wisconsin, in summer 2015. Participants included members from 1 largely Latino community and a second primarily African American neighborhood. A certified bicycling instructor led a 12-week bicycling intervention. Outcome measures including biking-related attitudes, self-reported physical activity, fitness as measured by the 6-minute step test, and biometric data were collected at baseline, 12 weeks, and 20 weeks. Thirty-eight participants completed the study. Barriers to bicycling declined significantly among intervention group participants at 12 weeks with some declines persisting to 20 weeks. Bicycling for leisure or non work transportation increased significantly more in the intervention than control group from baseline to 12 weeks but this difference attenuated by 20 weeks. Both groups increased their fitness between baseline and 12 weeks, with a trend towards greater gains in the bicycling intervention group. No significant change in biometric measurements was seen at either 12 weeks or 20 weeks. Despite the small study size, this bicycling intervention decreased perceived barriers to bicycling and increased bicycling activity in low-income minority participants. These findings support a larger-scale study to measure fitness and health changes from bicycling interventions.

Stereocontrolled synthesis of polyhydroxylated bicyclic azetidines as a new class of iminosugars.

Science.gov (United States)

Malinowski, Maciej; Hensienne, Raphaël; Kern, Nicolas; Tardieu, Damien; Bodlenner, Anne; Hazelard, Damien; Compain, Philippe

2018-06-12

We report herein the development of a stereodivergent route towards polyhydroxylated bicyclic azetidine scaffolds, namely 6-azabicyclo[3.2.0]heptane derivatives. The strategy hinges on a common bicyclic β-lactam precursor, which is forged by way of a rare example of a cationic Dieckmann-type reaction, followed by IBX-mediated desaturation. Substrate-controlled diastereoselective oxidations then allow the divergent preparation of novel iminosugar mimics.

Development of a solar-powered electric bicycle in bike sharing transportation system

Science.gov (United States)

Adhisuwignjo, S.; Siradjuddin, I.; Rifa'i, M.; Putri, R. I.

2017-06-01

The increasing mobility has directly led to deteriorating traffic conditions, extra fuel consumption, increasing automobile exhaust emissions, air pollution and lowering quality of life. Apart from being clean, cheap and equitable mode of transport for short-distance journeys, cycling can potentially offer solutions to the problem of urban mobility. Many cities have tried promoting cycling particularly through the implementation of bike-sharing. Apparently the fourth generation bikesharing system has been promoted utilizing electric bicycles which considered as a clean technology implementation. Utilization of solar power is probably the development keys in the fourth generation bikesharing system and will become the standard in bikesharing system in the future. Electric bikes use batteries as a source of energy, thus they require a battery charger system which powered from the solar cells energy. This research aims to design and implement electric bicycle battery charging system with solar energy sources using fuzzy logic algorithm. It is necessary to develop an electric bicycle battery charging system with solar energy sources using fuzzy logic algorithm. The study was conducted by means of experimental method which includes the design, manufacture and testing controller systems. The designed fuzzy algorithm have been planted in EEPROM microcontroller ATmega8535. The charging current was set at 1.2 Amperes and the full charged battery voltage was observed to be 40 Volts. The results showed a fuzzy logic controller was able to maintain the charging current of 1.2 Ampere with an error rate of less than 5% around the set point. The process of charging electric bike lead acid batteries from empty to fully charged was 5 hours. In conclusion, the development of solar-powered electric bicycle controlled using fuzzy logic controller can keep the battery charging current in solar-powered electric bicycle to remain stable. This shows that the fuzzy algorithm can be used as

Laboratory and Field-Based Evaluation of Short-Term Effort with Maximal Intensity in Individuals with Intellectual Disabilities

Directory of Open Access Journals (Sweden)

Lencse-Mucha Judit

2015-12-01

Full Text Available Results of previous studies have not indicated clearly which tests should be used to assess short-term efforts of people with intellectual disabilities. Thus, the aim of the present study was to evaluate laboratory and field-based tests of short-term effort with maximal intensity of subjects with intellectual disabilities. Twenty four people with intellectual disability, who trained soccer, participated in this study. The 30 s Wingate test and additionally an 8 s test with maximum intensity were performed on a bicycle ergometer. The fatigue index, maximal and mean power, relative maximal and relative mean power were measured. Overall, nine field-based tests were conducted: 5, 10 and 20 m sprints, a 20 m shuttle run, a seated medicine ball throw, a bent arm hang test, a standing broad jump, sit-ups and a hand grip test. The reliability of the 30 s and 8 s Wingate tests for subjects with intellectual disability was confirmed. Significant correlation was observed for mean power between the 30 s and 8 s tests on the bicycle ergometer at a moderate level (r >0.4. Moreover, significant correlations were indicated between the results of laboratory tests and field tests, such as the 20 m sprint, the 20 m shuttle run, the standing long jump and the medicine ball throw. The strongest correlation was in the medicine ball throw. The 30 s Wingate test is a reliable test assessing maximal effort in subjects with intellectual disability. The results of this research confirmed that the 8 s test on a bicycle ergometer had a moderate correlation with the 30 s Wingate test in this population, thus, this comparison needs further investigation to examine alternativeness of the 8 s to 30 s Wingate tests. The non-laboratory tests could be used to indirectly assess performance in short-term efforts with maximal intensity.

Laboratory and Field-Based Evaluation of Short-Term Effort with Maximal Intensity in Individuals with Intellectual Disabilities

Science.gov (United States)

Lencse-Mucha, Judit; Molik, Bartosz; Marszałek, Jolanta; Kaźmierska-Kowalewska, Kalina; Ogonowska-Słodownik, Anna

2015-01-01

Results of previous studies have not indicated clearly which tests should be used to assess short-term efforts of people with intellectual disabilities. Thus, the aim of the present study was to evaluate laboratory and field-based tests of short-term effort with maximal intensity of subjects with intellectual disabilities. Twenty four people with intellectual disability, who trained soccer, participated in this study. The 30 s Wingate test and additionally an 8 s test with maximum intensity were performed on a bicycle ergometer. The fatigue index, maximal and mean power, relative maximal and relative mean power were measured. Overall, nine field-based tests were conducted: 5, 10 and 20 m sprints, a 20 m shuttle run, a seated medicine ball throw, a bent arm hang test, a standing broad jump, sit-ups and a hand grip test. The reliability of the 30 s and 8 s Wingate tests for subjects with intellectual disability was confirmed. Significant correlation was observed for mean power between the 30 s and 8 s tests on the bicycle ergometer at a moderate level (r >0.4). Moreover, significant correlations were indicated between the results of laboratory tests and field tests, such as the 20 m sprint, the 20 m shuttle run, the standing long jump and the medicine ball throw. The strongest correlation was in the medicine ball throw. The 30 s Wingate test is a reliable test assessing maximal effort in subjects with intellectual disability. The results of this research confirmed that the 8 s test on a bicycle ergometer had a moderate correlation with the 30 s Wingate test in this population, thus, this comparison needs further investigation to examine alternativeness of the 8 s to 30 s Wingate tests. The non-laboratory tests could be used to indirectly assess performance in short-term efforts with maximal intensity. PMID:26834874

physiological effects of the amphetamines during exercise

African Journals Online (AJOL)

Oxygen consumption, heart rate, minute ventilation and blood lactate were measured on two champion cyclisTs at work rates from 45 to 362 W (2 000 - 16 000 ft-Ib / min) on a bicycle ergometer after administration of a placebo and after 10 mg of methamphetamine, withoUT their know- ledge of which was given.

Physiological effects of the amphetamines during exercise ...

African Journals Online (AJOL)

Oxygen consumption, heart rate, minute ventilation and blood lactate were measured on two champion cyclists at work rates from 45 to 362 W (2 000 - 16 000 ft-Ib / min) on a bicycle ergometer after administration of a placebo and after 10 mg of methamphetamine, without their knowledge of which was given. No differences ...

On the Implications of Sense of Control over Bicycling : Design of a Physical Stamina-Aware Bike

OpenAIRE

Lee, Chao-Lung; Lee, Da; Cheng, Yun-Maw; Sandnes, Frode Eika; Chen, Li-Chieh; Chen, Wei-Chia

2010-01-01

Bicycling has become a mainstream activity among the environmental aware generation. Bicycling communities have gradually shown interests in quantitative data of the bicycling experiences such as road roughness, inclination, pollution, etc. Bikers utilize these data to infer the possible stamina cost and quality of surroundings. This supports them to make a better decision. This study assumes that fitness level indexed by stamina cost could enhance a biker's sense of c...

"Bicycles May Use Full Lane" Signage Communicates U.S. Roadway Rules and Increases Perception of Safety.

Science.gov (United States)

Hess, George; Peterson, M Nils

2015-01-01

Many global challenges, including obesity, health care costs, and climate change, could be addressed in part by increasing the use of bicycles for transportation. Concern about the safety of bicycling on roadways is frequently cited as a deterrent to increasing bicycle use in the USA. The use of effective signage along roadways might help alleviate these concerns by increasing knowledge about the rights and duties of bicyclists and motorists, ideally reducing crashes. We administered a web-based survey, using Twitter for recruitment, to examine how well three US traffic control devices communicated the message that bicyclists are permitted in the center of the travel lane and do not have to "get out of the way" to allow motorists to pass without changing lanes: "Bicycles May Use Full Lane" and "Share the Road" signage, and Shared Lane Markings on the pavement. Each was compared to an unsigned roadway. We also asked respondents whether it was safe for a bicyclist to occupy the center of the travel lane. "Bicycles May Use Full Lane" signage was the most consistently comprehended device for communicating the message that bicyclists may occupy the travel lane and also increased perceptions of safety. "Share the Road" signage did not increase comprehension or perceptions of safety. Shared Lane Markings fell somewhere between. "Bicycles May Use Full Lane" signage showed notable increases in comprehension among novice bicyclists and private motor vehicle commuters, critical target audiences for efforts to promote bicycling in the USA. Although limited in scope, our survey results are indicative and suggest that Departments of Transportation consider replacing "Share the Road" with "Bicycles May Use Full Lane" signage, possibly combined with Shared Lane Markings, if the intent is to increase awareness of roadway rights and responsibilities. Further evaluation through virtual reality simulations and on-road experiments is merited.

"Bicycles May Use Full Lane" Signage Communicates U.S. Roadway Rules and Increases Perception of Safety.

Directory of Open Access Journals (Sweden)

George Hess

Full Text Available Many global challenges, including obesity, health care costs, and climate change, could be addressed in part by increasing the use of bicycles for transportation. Concern about the safety of bicycling on roadways is frequently cited as a deterrent to increasing bicycle use in the USA. The use of effective signage along roadways might help alleviate these concerns by increasing knowledge about the rights and duties of bicyclists and motorists, ideally reducing crashes. We administered a web-based survey, using Twitter for recruitment, to examine how well three US traffic control devices communicated the message that bicyclists are permitted in the center of the travel lane and do not have to "get out of the way" to allow motorists to pass without changing lanes: "Bicycles May Use Full Lane" and "Share the Road" signage, and Shared Lane Markings on the pavement. Each was compared to an unsigned roadway. We also asked respondents whether it was safe for a bicyclist to occupy the center of the travel lane. "Bicycles May Use Full Lane" signage was the most consistently comprehended device for communicating the message that bicyclists may occupy the travel lane and also increased perceptions of safety. "Share the Road" signage did not increase comprehension or perceptions of safety. Shared Lane Markings fell somewhere between. "Bicycles May Use Full Lane" signage showed notable increases in comprehension among novice bicyclists and private motor vehicle commuters, critical target audiences for efforts to promote bicycling in the USA. Although limited in scope, our survey results are indicative and suggest that Departments of Transportation consider replacing "Share the Road" with "Bicycles May Use Full Lane" signage, possibly combined with Shared Lane Markings, if the intent is to increase awareness of roadway rights and responsibilities. Further evaluation through virtual reality simulations and on-road experiments is merited.

Validity of a device designed to measure braking power in bicycle disc brakes.

Science.gov (United States)

Miller, Matthew C; Fink, Philip W; Macdermid, Paul William; Perry, Blake G; Stannard, Stephen R

2017-07-21

Real-world cycling performance depends not only on exercise capacities, but also on efficiently traversing the bicycle through the terrain. The aim of this study was to determine if it was possible to quantify the braking done by a cyclist in the field. One cyclist performed 408 braking trials (348 on a flat road; 60 on a flat dirt path) over 5 days on a bicycle fitted with brake torque and angular velocity sensors to measure brake power. Based on Newtonian physics, the sum of brake work, aerodynamic drag and rolling resistance was compared with the change in kinetic energy in each braking event. Strong linear relationships between the total energy removed from the bicycle-rider system through braking and the change in kinetic energy were observed on the tar-sealed road (r 2  = 0.989; p brake torque and angular velocity sensors are valid for calculating brake power on the disc brakes of a bicycle in field conditions. Such a device may be useful for investigating cyclists' ability to traverse through various terrains.

A physiological and biomechanical comparison of over-ground, treadmill and ergometer wheelchair propulsion.

Science.gov (United States)

Mason, Barry; Lenton, John; Leicht, Christof; Goosey-Tolfrey, Victoria

2014-01-01

The purpose of the study was to determine which laboratory-based modality provides the most valid physiological and biomechanical representation of over-ground sports wheelchair propulsion. Fifteen able-bodied participants with previous experience of wheelchair propulsion performed a 3-minute exercise trial at three speeds (4, 6 and 8 km ∙ h(-1)) in three testing modalities over separate sessions: (i) over-ground propulsion on a wooden sprung surface; (ii) wheelchair ergometer propulsion; (iii) treadmill propulsion at four different gradients (0%, 0.7%, 1.0% and 1,3%). A 0.7% treadmill gradient was shown to best reflect the oxygen uptake (7.3 to 9.1% coefficient of variation (CV)) and heart rate responses (4.9 to 6.4% CV) of over-ground propulsion at 4 and 6 km ∙ h(-1). A 1.0% treadmill gradient provided a more valid representation of oxygen uptake during over-ground propulsion at 8 km ∙ h(-1) (8.6% CV). Physiological demand was significantly underestimated in the 0% gradient and overestimated in the 1.3% gradient and wheelchair ergometer trials compared to over-ground trials (Ppropulsion at lower speeds (4 and 6 km ∙ h(-1)) whereas a 1.0% gradient may be more suitable at 8 km ∙ h(-1).

Food-dependent exercise-induced anaphylaxis to flaxseed

Directory of Open Access Journals (Sweden)

Helmut Gall

2000-01-01

Full Text Available The present paper reports on a 26-year-old atopic patient suffering from seasonal rhinoconjunctivitis and flexural eczemas. On two occasions, he experienced nausea, generalized urticaria and dyspnea within 2 h after consumption of a wholemeal roll and subsequent exercise (football training or walking. In each case, the episode necessitated intravenous emergency therapy with an antihistamine and a corticosteroid. In order to elucidate the two exercise-induced anaphylactic events we performed prick tests and the radioallergosorbent test (RAST with the ingredients of the wholemeal roll. Only flaxseed gave positive results. In addition, we performed an exercise test on a bicycle ergometer (15 min at 150 W and an oral challenge test with foods, using a double-blind and placebo-controlled study. Only oral challenge with a teaspoon of flaxseed with additional exercise on the bicycle ergometer elicited itching, urticaria, nausea, coughing and dyspnea. The oral challenge with flaxseed followed by exercise induced immediate-type reactions and, thus, led to the diagnosis of food-dependent exercise- induced anaphylaxis to flaxseed.

Testing of Badminton-Specific Endurance.

Science.gov (United States)

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

2016-09-01

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

Effects of a 6-Week Aquatic Treadmill Exercise Program on Cardiorespiratory Fitness and Walking Endurance in Subacute Stroke Patients: A PILOT TRIAL.

Science.gov (United States)

Han, Eun Young; Im, Sang Hee

2017-03-15

To assess the feasibility and safety of a 6-week course of water walking performed using a motorized aquatic treadmill in individuals with subacute stroke for cardiorespiratory fitness, walking endurance, and activities of daily living. Twenty subacute stroke patents were randomly assigned to aquatic treadmill exercise (ATE) or land-based exercise (LBE). The ATE group (n = 10) performed water-based aerobic exercise on a motorized aquatic treadmill, and the LBE group (n = 10) performed land-based aerobic exercise on a cycle ergometer. Both groups performed aerobic exercise for 30 minutes, 5 times per week for 6 weeks. Primary outcome measures were 6-minute walk test for walking endurance and cardiopulmonary fitness parameters of a symptom-limited exercise tolerance test, and secondary measures were Korean version of the Modified Barthel Index (K-MBI) for activities of daily living. All variables were assessed at baseline and at the end of the intervention. The ATE group showed significant improvements in 6-minute walk test (P = .005), peak oxygen uptake (V·o2peak; P = .005), peak heart rate (P = .007), exercise tolerance test duration (P = .005), and K-MBI (P = .008). The LBE group showed a significant improvement only in K-MBI (P = .012). In addition, improvement in V·o2peak was greater in the ATE than in the LBE group. This preliminary study showed that a 6-week ATE program improved peak aerobic capacity and walking endurance in patients with subacute stroke. The improvement in V·o2peak after an ATE exercise program was greater than that observed after an LBE program. Therefore, ATE effectively improves cardiopulmonary fitness in patients with subacute stroke.

Effect of bicycle saddle designs on the pressure to the perineum of the bicyclist.

Science.gov (United States)

Lowe, Brian D; Schrader, Steven M; Breitenstein, Michael J

2004-06-01

Increasing awareness of an association between bicycling and male sexual dysfunction has led to the appearance of a variety of bicycle saddles that share the design objective of reducing pressure in the groin of the cyclist by removal of the narrow protruding nose of the saddle. This study compared three of these saddle designs to a traditional sport/road racing saddle with a narrow protruding nose in terms of pressure in the region of the perineum (groin) of the cyclist. Saddle, pedal, and handlebar contact pressure were measured from 33 bicycle police patrol officers pedaling a stationary bicycle at a controlled cadence and workload. Pressure was characterized over the saddle as a whole and over a region of the saddle assumed to represent pressure on the cyclist's perineum located anteriorly to the ischial tuberosities. The traditional sport/racing saddle was associated with more than two times the pressure in the perineal region than the saddles without a protruding nose (P perineum of the bicyclist.

Wireless controller and smartphone based interaction system for electric bicycles.

Directory of Open Access Journals (Sweden)

Jorge REVUELTA HERRERO

2016-07-01

Full Text Available Throughout the last years, great improvements have been made in the automotive industry, a sector with a high impact in both economics and social environments. Many development efforts have targeted on satisfying the need of providing smart environments to the end user in vehicles, such as cars. This paper proposes a brand-new solution in the automotive field, consisting of a new product family which aims to transform the traditional bicycle to an electric bicycle using an architecture that provides an adaptive environment to the user, improving the driving experience enabling value-added services.

Traumatic Globe Subluxation and Intracranial Injury Caused by Bicycle Brake Handle.

Science.gov (United States)

Poroy, Ceren; Cibik, Cansu; Yazici, Bulent

2016-09-01

Penetration of a bicycle brake handle into the orbit is a rare and serious type of trauma. Globe subluxation due to such trauma has not been previously reported. A 10-year-old girl presented after falling from a bicycle, which resulted in the handbrake penetrating her right upper eyelid. On examination, the globe was subluxated anteriorly, there was no light perception, and the pupilla was fixed and dilated. Radiologic studies revealed orbitonasal fractures, hemorrhage, emphysema in the orbit and cranium, and rupture of the extraocular muscles. The globe was replaced into the orbit with the help of lateral cantholysis and orbital septotomy. During 22 months of follow-up, the globe remained intact, but total loss of vision, blepharoptosis, and extraocular motility restriction persisted. This case and previous reports show that bicycle brake handles can cause severe, penetrating orbital and cerebral traumas that can result in vision loss or fatality. Brake handles should be designed to protect bicyclists from such injuries.

Endurance Training - Science and Practice

African Journals Online (AJOL)

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

The different ways to get on and off a bicycle for young and old

NARCIS (Netherlands)

Dubbeldam, R.; Baten, C. T.M.; Straathof, P.T.C.; Buurke, J. H.; Rietman, J. S.

2017-01-01

In the Netherlands, each year 12,000 older cyclists require medical attention due to a single-bicycle accident where no other party is directly involved. Most of these accidents occur at low cycling velocities and 20% occur during (dis)mounting the bicycle. Little is known about the strategies and

Maximal aerobic power in cycle ergometry in middle-aged men and women, active in sports, in relation to age and physical activity.

Science.gov (United States)

Bovens, A M; van Baak, M A; Vrencken, J G; Wijnen, J A; Saris, W H; Verstappen, F T

1993-02-01

Reliable standards of maximal power output in middle-aged and physically active men and women are desirable in sports-medical practice. For this purpose maximal cycle ergometer tests were evaluated in 2038 men and 898 women over 40 years of age (46.8 +/- 6.1 years (mean +/- SD) and 47.5 +/- 6.6 years), who volunteered in a sports-medical check-up and all of whom were active in sports for at least three months in the year preceding the screening (4.3 +/- 3.1 hours/week respectively 3.6 +/- 2.5 hours/week). The range of maximal values for power output (Wmax), heart rate (HRmax), systolic blood pressure (SBPmax) and peak plasma lactate concentrations (PPLa) during progressive cycle ergometer testing are presented for males and females who were divided into groups with a 5-years age difference. Wmax varied with sex (male = 1, female = 0), age (year) and height (cm); Wmax = 65.3 x (sex) + 2.0 x (height) -1.9 x (age) - 67.9 (See = 38.2; r = 0.76). The weighing of different factors that influence performance was also studied by multiple regression analysis to provide improved precision in standards used to interpret exercise tests. In both men and women about half of the variation of Wmax could be explained by the independent variables age, body mass, body fat, smoking habits, vital capacity, heart rate, and physical activity parameters. It is concluded that active involvement in endurance sports and/or the use of the bicycle for transport, contributed substantially to cardiovascular fitness in healthy, middle-aged men and women.

Evaluation of a promotional strategy to increase bicycle helmet use by children.

Science.gov (United States)

Parkin, P C; Spence, L J; Hu, X; Kranz, K E; Shortt, L G; Wesson, D E

1993-04-01

Bicycle-related head injuries are an important cause of death and disability, despite the availability of helmets. The objective of this study was to evaluate the effectiveness of a school-based bicycle helmet promotion program in increasing helmet use by children while controlling for secular trends. Two high-income and two low-income schools in an urban Canadian community were selected to receive a bicycle helmet promotion intervention, with the remaining 18 schools serving as controls. Approximately 1800 observations of bicycling children were made at randomly selected observational sites 2 to 5 months after the intervention to assess changes in behavior. Helmet use at all observation sites tripled from 3.4% (1990, preintervention) to 16% (1991, postintervention). In the high-income intervention area, observed helmet use rose dramatically from 4% to 36% in contrast to the more modest increase in the high-income control area from 4% to 15%. In the low-income intervention area, there was a modest increase from 1% to 7%, but it did not differ from the increase in the low-income control area from 3% to 13%. The program was highly successful in children of high-income families but not in children of low-income families. Developing strategies for low-income families remains a priority.

Influence of the cognitive workload on bicycle safety at four-legged intersections

DEFF Research Database (Denmark)

Kveladze, Irma; Agerholm, Niels

2018-01-01

is the influence of workload capacity on bicyclists spatial behaviour in a natural environment of four-legged intersections. Method: Due to the traffic safety of test participants, the study is divided in two phases. In the first phase, the actual physical environment of the four-legged intersection and bicyclists......-legged intersection. The eye tracking glasses will be used to make video and audio recording of visible field of where or how long bicyclists are allocating their visual attention while riding a bicycle and facing obstacles when crossing the four-legged intersection. On the second phase, a bicycle riding simulator...... riding task. This will allow to understand the allocation of bicyclists attention between primary and secondary tasks, to reveal the limit of the information processing capacity during biking. Results expected: Two experimental results will be incorporated to gain in-depth knowledge on bicycle accidents...

Different cycle ergometer outcomes in severely obese men and women without documented cardiopulmonary morbidities before bariatric surgery

NARCIS (Netherlands)

Dolfing, JG; Dubois, EF; Wolffenbuttel, BHR; ten Hoor-Aukema, NM; Schweitzer, DH

Study objectives: The number of severely obese patients undergoing bariatric surgery is increasing. No incremental cycle ergometer data are available in this category of patients. The current study was undertaken to provide information and to compare outcomes between severely obese men and women

Study of the health effects of bicycling in an urban atmosphere. Final report

Energy Technology Data Exchange (ETDEWEB)

Waldman, M.; Weiss, S.; Articola, W.

1977-10-14

This report analyzes data on the health effects of bicycling in an urban environment through intensive study of ten healthy male subjects bicycling or driving in systematically varied conditions in the streets of Washington, D.C. Evaluation criteria for available technology and instrumentation are included and a methodology is developed for route selection. Specific air pollutants (carbon monoxide, ozone, sulfates, nitrates, and particulates) are measured concurrently with exposure and subsequent changes in health status identified through pulmonary function testing, cardiovascular testing, and blood and symptoms analysis. The report concludes that no major adverse short-term health effects were noted for ten healthy male subjects while bicycling or driving in levels of pollution and thermal stress encountered during the study period. Recommendations for further research are also presented.

Bicycle Design : A different approach to improving on the world human powered speed records

NARCIS (Netherlands)

Epema, H.K.; Van den Brand, S.; Gregoor, W.; Kooijman, J.D.G.; Pereboom, H.P.; Wielemaker, D.C.; Van der Zweep, C.J.

2012-01-01

The current International Human Powered Vehicle Association world records for faired bicycles stand at 133.284km/h for the 200m flying start speed record and 91.562 km for the hour record. Traditionally the recumbent bicycles that have been developed for breaking one of either of these records have

Prediction of performance in Vasaloppet through long lasting ski- ergometer and rollerski tests in cross-country skiers

DEFF Research Database (Denmark)

Mygind, Erik; Wulff, Kristian; Jensen, Mads Rosenkilde

2015-01-01

-ergometer and Rollerski field tests correlate strongly with performance in Vasaloppet and therefore might be useful test tools for recreational skiers who wish to participate in long lasting c-c competitions. Keywords: Cross-country ski training, Upper body, Exercise intensity, Field test, Body composition blood lactate......The main purpose was to investigate if long lasting cross-country (c-c) test procedures could predict performance time in ‘Vasaloppet’ and secondly the effect of a 16 weeks training period on a 90 min double poling performance test. 24 moderate trained c-c skiers participated in the study...... and completed Vasaloppet. All skiers carried out pre and post training tests in a 90 minutes ski-ergometer double poling test and a 120 minutes rollerski field test on a closed paved circuit. 19 skiers provided detailed training logs that could sufficiently establish their training preparation for Vasaloppet...

Bicycle-Related Shoulder Injuries: Etiology and the Need for Protective Gear.

Science.gov (United States)

Goldstein, Yariv; Dolkart, Oleg; Kaufman, Ehud; Amar, Eyal; Sharfman, Zachary T; Rath, Ehud; Mozes, Gavriel; Maman, Eran

2016-01-01

The popularity of bicycle riding for recreation, exercise and transportation has grown enormously in recent years, which has led to an increased incidence of bicycle-related injuries. While these injuries involve mainly the musculoskeletal system, data on shoulder-specific injuries incurred while bike riding are lacking. Classifying these shoulder injuries may provide insight and assistance in the creation and implementation of effective protective gear and measures. To investigate the types and mechanisms of shoulder injuries among cyclists. This study retrospectively examined all cyclists who incurred shoulder injuries while riding and were admitted to the emergency department and shoulder clinic between January 2008 and November 2013. The study included 157 subjects with various bicycle-related shoulder injuries treated with either conservative or surgical measures. Eighty-four percent of injuries were caused by a direct blow to the shoulder, 7% by falling on an outstretched hand, 6% were traction injuries, and 3% were due to hyperabduction. Nine different clinical types of injury were observed; the most common injuries were clavicle fractures (32%), followed by acromioclavicular joint dislocations (22%), rotator cuff tears (22%), and humeral fractures (8%). Fifty-one percent of subjects were managed with conservative care and the remaining patients required surgical interventions. Shoulder injuries incurred while riding a bicycle span the entire spectrum of shoulder injuries and often result in debilitating conditions. Although the use of helmets is increasing, there is currently no effective protective gear or measures to prevent riders from suffering shoulder injuries.

Modelling mode choice in short trips - shifting from car to bicycle

DEFF Research Database (Denmark)

Halldórsdóttir, Katrín; Christensen, Linda; Jensen, Thomas Christian

2011-01-01

-economic variables of a representative sample of the population. The investigated sample includes 11,072 observations. The model considers five alternatives (i.e., car driver, car passenger, public transport, walk and obviously bike), for which level of service variables are calculated through assignment procedures...... relevance of the cost for short trips. Expectedly, the selection of bicycle as mode for short trips is positively related to owning a bicycle and negatively linked to owning one or more cars. Urban density has also positive correlation with the selection of sustainable transport modes....

“Bicycles May Use Full Lane” Signage Communicates U.S. Roadway Rules and Increases Perception of Safety

Science.gov (United States)

2015-01-01

Many global challenges, including obesity, health care costs, and climate change, could be addressed in part by increasing the use of bicycles for transportation. Concern about the safety of bicycling on roadways is frequently cited as a deterrent to increasing bicycle use in the USA. The use of effective signage along roadways might help alleviate these concerns by increasing knowledge about the rights and duties of bicyclists and motorists, ideally reducing crashes. We administered a web-based survey, using Twitter for recruitment, to examine how well three US traffic control devices communicated the message that bicyclists are permitted in the center of the travel lane and do not have to “get out of the way” to allow motorists to pass without changing lanes: “Bicycles May Use Full Lane” and “Share the Road” signage, and Shared Lane Markings on the pavement. Each was compared to an unsigned roadway. We also asked respondents whether it was safe for a bicyclist to occupy the center of the travel lane. “Bicycles May Use Full Lane” signage was the most consistently comprehended device for communicating the message that bicyclists may occupy the travel lane and also increased perceptions of safety. “Share the Road” signage did not increase comprehension or perceptions of safety. Shared Lane Markings fell somewhere between. “Bicycles May Use Full Lane” signage showed notable increases in comprehension among novice bicyclists and private motor vehicle commuters, critical target audiences for efforts to promote bicycling in the USA. Although limited in scope, our survey results are indicative and suggest that Departments of Transportation consider replacing “Share the Road” with “Bicycles May Use Full Lane” signage, possibly combined with Shared Lane Markings, if the intent is to increase awareness of roadway rights and responsibilities. Further evaluation through virtual reality simulations and on-road experiments is merited. PMID

Allene functionalization via bicyclic methylene aziridines.

Science.gov (United States)

Boralsky, Luke A; Marston, Dagmara; Grigg, R David; Hershberger, John C; Schomaker, Jennifer M

2011-04-15

The oxidative functionalization of olefins is a common method for the formation of vicinal carbon-heteroatom bonds. However, oxidative methods to transform allenes into synthetic motifs containing three contiguous carbon-heteroatom bonds are much less developed. This paper describes the use of bicyclic methylene aziridines (MAs), prepared via intramolecular allene aziridination, as scaffolds for functionalization of all three allene carbons. © 2011 American Chemical Society

Latent segmentation based count models: Analysis of bicycle safety in Montreal and Toronto.

Science.gov (United States)

Yasmin, Shamsunnahar; Eluru, Naveen

2016-10-01

The study contributes to literature on bicycle safety by building on the traditional count regression models to investigate factors affecting bicycle crashes at the Traffic Analysis Zone (TAZ) level. TAZ is a traffic related geographic entity which is most frequently used as spatial unit for macroscopic crash risk analysis. In conventional count models, the impact of exogenous factors is restricted to be the same across the entire region. However, it is possible that the influence of exogenous factors might vary across different TAZs. To accommodate for the potential variation in the impact of exogenous factors we formulate latent segmentation based count models. Specifically, we formulate and estimate latent segmentation based Poisson (LP) and latent segmentation based Negative Binomial (LNB) models to study bicycle crash counts. In our latent segmentation approach, we allow for more than two segments and also consider a large set of variables in segmentation and segment specific models. The formulated models are estimated using bicycle-motor vehicle crash data from the Island of Montreal and City of Toronto for the years 2006 through 2010. The TAZ level variables considered in our analysis include accessibility measures, exposure measures, sociodemographic characteristics, socioeconomic characteristics, road network characteristics and built environment. A policy analysis is also conducted to illustrate the applicability of the proposed model for planning purposes. This macro-level research would assist decision makers, transportation officials and community planners to make informed decisions to proactively improve bicycle safety - a prerequisite to promoting a culture of active transportation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Utilizing the Bicycle for Non-Traditional Activities

Science.gov (United States)

Maina, Michael P.; Maina, Julie Schlegel; Sebek, Ludek; Hoffmanova, Jana; Kane, Jennifer Jackson

2012-01-01

This article examines the bicycle as not simply a means of transportation or as an exercise device, but rather as a vehicle for teambuilding and problem solving activities within a physical education curriculum. The activities described in this article focus on bike-centered initiatives that foster creative problem solving. They have universal…

BICYCLE HELMET DESIGN AND THE VIRTUAL VALIDATION OF THE IMPACT, AERODYNAMICS AND PRODUCTION PROCESS

Directory of Open Access Journals (Sweden)

Bojan Boshevski

2017-12-01

Full Text Available This paper presents the development process of a bicycle helmet through individual research, creation, presentation and analysis of the results of the most important product development stages. The quality of the development and manufacturing process of the protective equipment for extreme sports is an imperative for a successful product and its flawless function. The design of the bicycle helmet is made following the rules of the design in order to create a well-founded and functional product. After creating design sketches, a virtual prototype was developed in "SolidWorks" using the required ergonomic dimensions. 3D printed model of the human head with adapted ergonomic dimensions and the designed bicycle helmet was developed in order to verify the applied ergonomic measures. The virtual model will be used as an input in the finite element analysis of the helmet impact test based on the EN1078 standard and the aerodynamic simulations executed in "SolidWorks Simulation and Flow Simulation", for verification of the impact and aerodynamic properties. Virtual testing of aerodynamic features and the ability of the bicycle helmet to allow ventilation of the user's head indicate that the helmet performs its function in the desired way. Also, the virtual prototype will be used for the production process simulation in "SolidWorks Plastics" in order to analyze the production of the bicycle helmet. The polycarbonate helmet outer shell is subject to a number of simulations for the sake of analyzing the production process in order to obtain the desired characteristics of the polycarbonate outer shell and to avoid the disadvantages that occur in the manufacturing process. The main goal of this paper is to develop a safety bicycle helmet with improved ergonomic, validation of impact, aerodynamic characteristics and production process in order to produce a high quality product for mass use.

Training modalities: impact on endurance capacity.

Science.gov (United States)

Flueck, Martin; Eilers, Wouter

2010-03-01

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

Conversion Of An Ordinary N Bicycle Into An Electric Bike And Related Research

Directory of Open Access Journals (Sweden)

Marius Janavičius

2014-05-01

Full Text Available An electric bicycle as a transport and leisure vehicle is expected to have a promising future. Currently, he market offers a great choice of factory electric bicycles and conversion kits to remake an ordinary bicycle into an electric bike. Also, the increasing number of electric vehicles is determined by the reduction in costs for manufacturing of batteries and an evolution in battery technology. This article presents the implementation of an electric bike by selecting the “Golden Motor Technology” company’s electric front wheel conversion kit MagicPie3 and 16 cell 10Ah LiFePO4 battery. After installation of the engine and other components, experiments were conducted to evaluate the performance characteristics of the electric bike and check the manufacturer’s specifications.

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

DEFF Research Database (Denmark)

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

2016-01-01

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

THE EFFECT OF THE STATIC RELATIVE STRENGTH ON THE MAXIMUM RELATIVE RECEIVING OF OXYGEN

Directory of Open Access Journals (Sweden)

Abdulla Elezi

2011-09-01

Full Text Available Based on research on the sample of 263 students of age- 18 years, and used batteries of 9 tests for evaluation of the static relative strength and the criterion variable- maximum relative receiving of oxygen (VO2 ml / kg / min based on the Astrand test ,and on regression analysis to determine the influence of the static relative strength on the criterion variable maximum relative oxygen receiving, can be generally concluded that from 9 predictor variables statistically significant partial effect have 2variables. In hierarchical order, they are: the variable of static relative leg strength - endurance of the fingers (the angle of the lower leg and thigh 900 (SRL2 which arithmetic mean is 25.04 seconds and variable ctatic relative strength of arms and shoulders – push-up endurance in the balance beam (angle of the forearm and upper arm 900 ( SRA2 with arithmetic mean of 17.75 seconds. From the statistically influential significant predictor variables on the criterion variable one is from the static relative leg strength (SRL2 and the other is from the static relative strength of arm and shoulder area (SRA2. With the analysis of these relations we can conclude that the isometric contractions of the four headed thigh muscle and the isometric contractions of the three headed upper arm muscle are predominantly responsible for the successful execution of doing actions on a bicycle ergometer and not on the maximum relative receiving of oxygen.

Effect of Conjugated Linoleic Acid Intake on Endurance Exercise Performance and Anti-fatigue in Student Athletes.

Science.gov (United States)

Terasawa, Naoko; Okamoto, Ken; Nakada, Kenta; Masuda, Kazumi

2017-07-01

Conjugated linoleic acids (CLA) intake has been reported to reduce body fat mass or increase lean body mass and to improve exercise outcome by modulating testosterone in humans. These reports have studied mostly overweight subjects; few were athletes. Therefore, in this study, the effect of CLA intake on endurance performance and anti-fatigue in student athletes was investigated. A double-blind, crossover study was conducted with 10 male student athletes. Each subject was administered with either CLA (net 0.9 g/day) or a placebo for 14 days. They were subjected to an exercise tolerance test (steady loading) using a cycle ergometer on days 0 and 14. Peak VO 2 was determined for each subject using a graded loading test. The steady loading test was performed with a pedaling exercise load of 50% peak VO 2 for 40 min and then with a load of 70% peak VO 2 until exhaustion. Blood sampling and measurement of critical flicker frequency (CFF) were performed before and after exercise. The rate of perceived exertion (RPE) was measured serially during exercise. In the results, amount of body weight variation significantly increased and amount of body fat percentage variation tended to decrease by CLA intake, it might have an effect by increase in muscle mass. In addition, amount of exercise time variation significantly increased, amount of variation of CFF before and after exercise tended to increase, that of RPE during exercise tended to decrease, and that of creatine phosphokinase before and after exercise tended to decrease in the CLA group. These results suggested that CLA intake for 14 days might have an effect on endurance performance and anti-fatigue in student athletes.

Injuries to Cyclists due to a Dog-Bicycle Interaction.

Science.gov (United States)

Loder, Randall T; Yaacoub, Alan P

2018-05-01

 Both dogs and bicycles are common in our society and thus a dog-bicycle interaction resulting in an injury to a cyclist is possible. It was the purpose of this study to investigate such injuries.  The National Electronic Injury Surveillance System (NEISS) data for the 10-year period from 2006 through 2015 associated with bicycles were accessed. Injuries involving dogs were identified and the mechanism of injury determined. Due to the stratified and weighted nature of the NEISS data, statistical analyses were performed with SUDAAN 10 software (RTI International, Research Triangle Park, North Carolina, United States). A p  dogs were involved in 35,254 (0.67%) cases. The average age for those involved with a dog was 33.2 years and it was 25.5 years for those in which dogs were not involved. There were more females in the dog group (34.1 vs. 27.6%). Dog involvement increased from ages 0 to 14 years, then decreased until the age of 20 years and then progressively increased. Dog-associated injuries most frequently occurred away from home, involved the knee and distal lower extremity, 49.1% sustaining dog bites. Dog bites were more common in younger individuals. Four injury mechanisms (chased by a dog, hit/collided with a dog, swerved/tried to avoid a dog or riding with a dog) accounted for 97.5% of the injuries. Those chased by a dog were younger, more commonly released from the emergency department, had an injury involving the lower extremity and frequently sustained a bite. The most severe injuries were in those who swerved/tried to avoid a dog or hit a dog.  Approximately 1% of injuries to bicyclists are associated with dogs; one-half sustained a bite. Potential/proposed prevention strategies could be educational materials regarding bicycles and dogs to owners, dog restraint, student/parent education and educational materials in waiting rooms of veterinarians, paediatricians, family practice physicians and emergency rooms. Schattauer GmbH Stuttgart.

Investigation of Influential Factors for Bicycle Crashes Using a Spatiotemporal Model

Science.gov (United States)

Gill, G.; Sakrani, T.; Cheng, W.; Zhou, J.

2017-09-01

Despite the numerous potential advantages of indulging in bicycling, such as elevation of health and environment along with mitigation of congestion, the cyclists are a vulnerable group of commuters which is exposed to safety risks. This study aims to investigate the explanatory variables at transportation planning level which have a significant impact on the bicycle crashes. To account for the serial changes around the built environment, the linear time trend as well as time-varying coefficients are utilized for the covariates. These model modifications help account for the variations in the environment which may escape the incorporated variables due to lack of robustness in data. Also, to incorporate the interaction of roadway, demographic, and socioeconomic features within a Traffic Analysis Zone (TAZ), with the bicycle crashes of that area, a spatial correlation is integrated. This spatial correlation accounts for the spatially structured random effects which capture the unobserved heterogeneity and add towards building more comprehensive model with relatively precise estimates. Two different age groups, the student population in the TAZs, the presence of arterial roads and bike lanes, were observed to be statistically significant variables related with bicycle crashes. These observations will guide the transportation planning organizations which focus on the entity of TAZ while developing policies. The results of the current study establish a quantifies relationship between the significant factors and the crash count which will enable the planners to choose the most cost-efficient, yet most productive, factors which needs to be addressed for mitigation of crashes.

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

Science.gov (United States)

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

1989-01-01

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

A strategic approach to [6,6]-bicyclic lactones

DEFF Research Database (Denmark)

Jepsen, Tue Heesgaard; Glibstrup, Emil; Crestey, Francois Louis Jean

2017-01-01

We report an effective synthetic protocol to access [6,6]-bicyclic lactone moieties through a regio- and stereoselective intramolecular Mizoroki–Heck cross-coupling reaction followed by a 6π-electrocyclization. This method enabled the first synthesis of the elusive CD fragment of the Erythrina...

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

Modeling Mixed Bicycle Traffic Flow: A Comparative Study on the Cellular Automata Approach

Directory of Open Access Journals (Sweden)

Dan Zhou

2015-01-01

Full Text Available Simulation, as a powerful tool for evaluating transportation systems, has been widely used in transportation planning, management, and operations. Most of the simulation models are focused on motorized vehicles, and the modeling of nonmotorized vehicles is ignored. The cellular automata (CA model is a very important simulation approach and is widely used for motorized vehicle traffic. The Nagel-Schreckenberg (NS CA model and the multivalue CA (M-CA model are two categories of CA model that have been used in previous studies on bicycle traffic flow. This paper improves on these two CA models and also compares their characteristics. It introduces a two-lane NS CA model and M-CA model for both regular bicycles (RBs and electric bicycles (EBs. In the research for this paper, many cases, featuring different values for the slowing down probability, lane-changing probability, and proportion of EBs, were simulated, while the fundamental diagrams and capacities of the proposed models were analyzed and compared between the two models. Field data were collected for the evaluation of the two models. The results show that the M-CA model exhibits more stable performance than the two-lane NS model and provides results that are closer to real bicycle traffic.

Sensor design for outdoor racing bicycle field testing for human vibration comfort evaluation

International Nuclear Information System (INIS)

Vanwalleghem, Joachim; De Baere, Ives; Van Paepegem, Wim; Loccufier, Mia

2013-01-01

This paper is concerned with the vibrational comfort evaluation of the cyclist when cycling a rough surface. Outdoor comfort tests have so far only been done through instrumenting the bicycle with accelerometers. This work instruments a racing bicycle with custom-made contact force sensors and velocity sensors to acquire human comfort through the absorbed power method. Comfort evaluation is assessed at the hand–arm and seat interface of the cyclist with the bicycle. By means of careful finite-element analysis for designing the force gauges at the handlebar and the seat combined with precise calibration of both force and velocity sensors, all sensors have proven to work properly. Initial field tests are focused on the proper functioning of the designed sensors and their suitability for vibration comfort measurements. Tests on a cobblestone road reveal that the outcome of the absorbed power values is within the same range as those from laboratory tests found in the literature. This sensor design approach for outdoor testing with racing bicycles may give a new interpretation on evaluating the cyclist's comfort since the vibrational load is not only quantified in terms of acceleration but also in terms of force and velocity at the bicycle–cyclist contact points. (paper)

Feasibility of virtual reality augmented cycling for health promotion of people poststroke.

Science.gov (United States)

Deutsch, Judith E; Myslinski, Mary Jane; Kafri, Michal; Ranky, Richard; Sivak, Mark; Mavroidis, Constantinos; Lewis, Jeffrey A

2013-09-01

A virtual reality (VR) augmented cycling kit (VRACK) was developed to address motor control and fitness deficits of individuals with chronic stroke. In this article, we report on the safety, feasibility, and efficacy of using the VR augmented cycling kit to improve cardiorespiratory (CR) fitness of individuals in the chronic phase poststroke. Four individuals with chronic stroke (47-65 years old and ≥3 years poststroke), with residual lower extremity impairments (Fugl-Meyer 24-26/34), who were limited community ambulators (gait speed range 0.56-1.1 m/s) participated in this study. Safety was defined as the absence of adverse events. Feasibility was measured using attendance, total exercise time, and "involvement" measured with the presence questionnaire (PQ). Efficacy of CR fitness was evaluated using a submaximal bicycle ergometer test before and after an 8-week training program. The intervention was safe and feasible with participants having 1 adverse event, 100% adherence, achieving between 90 and 125 minutes of cycling each week, and a mean PQ score of 39 (SD 3.3). There was a statistically significant (13%; P = 0.035) improvement in peak VO(2), with a range of 6% to 24.5%. For these individuals, poststroke, VR augmented cycling, using their heart rate to set their avatar's speed, fostered training of sufficient duration and intensity to promote CR fitness. In addition, there was a transfer of training from the bicycle to walking endurance. VR augmented cycling may be an addition to the therapist's tools for concurrent training of mobility and health promotion of individuals poststroke.

Aerobic Exercise Training Improves Orthostatic Tolerance in Aging Humans.

Science.gov (United States)

Xu, Diqun; Wang, Hong; Chen, Shande; Ross, Sarah; Liu, Howe; Olivencia-Yurvati, Albert; Raven, Peter B; Shi, Xiangrong

2017-04-01

This study was designed to test the hypothesis that aerobic exercise training of the elderly will increase aerobic fitness without compromising orthostatic tolerance (OT). Eight healthy sedentary volunteers (67.0 ± 1.7 yr old, four women) participated in 1 yr of endurance exercise training (stationary bicycle and/or treadmill) program at the individuals' 65%-75% of HRpeak. Peak O2 uptake (V˙O2peak) and HRpeak were determined by a maximal exercise stress test using a bicycle ergometer. Carotid baroreceptor reflex (CBR) control of HR and mean arterial pressure (MAP) were assessed by a neck pressure-neck suction protocol. Each subject's maximal gain (Gmax), or sensitivity, of the CBR function curves were derived from fitting their reflex HR and MAP responses to the corresponding neck pressure-neck suction stimuli using a logistic function curve. The subjects' OT was assessed using lower-body negative pressure (LBNP) graded to -50 mm Hg; the sum of the product of LBNP intensity and time (mm Hg·min) was calculated as the cumulative stress index. Training increased V˙O2peak (before vs after: 22.8 ± 0.92 vs 27.9 ± 1.33 mL·min·kg, P stress index was increased from 767 ± 68 mm Hg·min pretraining to 946 ± 44 mm Hg·min posttraining (P Aerobic exercise training improved the aerobic fitness and OT in elderly subjects. An improved OT is likely associated with an enhanced CBR function that has been reset to better maintain cerebral perfusion and cerebral tissue oxygenation during LBNP.

Harvesting energy from the counterbalancing (weaving) movement in bicycle riding.

Science.gov (United States)

Yang, Yoonseok; Yeo, Jeongjin; Priya, Shashank

2012-01-01

Bicycles are known to be rich source of kinetic energy, some of which is available for harvesting during speedy and balanced maneuvers by the user. A conventional dynamo attached to the rim can generate a large amount of output power at an expense of extra energy input from the user. However, when applying energy conversion technology to human powered equipments, it is important to minimize the increase in extra muscular activity and to maximize the efficiency of human movements. This study proposes a novel energy harvesting methodology that utilizes lateral oscillation of bicycle frame (weaving) caused by user weight shifting movements in order to increase the pedaling force in uphill riding or during quick speed-up. Based on the 3D motion analysis, we designed and implemented the prototype of an electro-dynamic energy harvester that can be mounted on the bicycle's handlebar to collect energy from the side-to-side movement. The harvester was found to generate substantial electric output power of 6.6 mW from normal road riding. It was able to generate power even during uphill riding which has never been shown with other approaches. Moreover, harvesting of energy from weaving motion seems to increase the economy of cycling by helping efficient usage of human power.

BUGS at work : a bicycle user group guide

Energy Technology Data Exchange (ETDEWEB)

NONE

2002-07-01

This guide provides practical advice to cyclists on how start a Bicycle User Group (BUG) at their workplace. It offers tools to encourage employers to be proactive in improving facilities in support of cycle commuting. Several BUGs across Canada have worked towards getting better bicycle parking, lockers and shower facilities at their workplace. Other incentives include policies such as flexible work hours for cyclist commuters; casual dress on Friday; reimbursement for the subsidized cost of free parking provided by employers; and, use of a company car if needed for company business during the work day. The advantages to employers include: reduced health care costs because cyclists are physically fit; decreased absenteeism; increased productivity; reduced parking costs; lower company transportation bills; and, a greener corporate image. BUGs provide cycling information ranging from cycling maps to pamphlets and they raise cycle awareness. This guide includes cycling survey samples and examples of successful BUG activities across Canada. refs., tabs., figs.

Energy Balance of Triathletes during an Ultra-Endurance Event

Directory of Open Access Journals (Sweden)

Anna Barrero

2014-12-01

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

Energy balance of triathletes during an ultra-endurance event.

Science.gov (United States)

Barrero, Anna; Erola, Pau; Bescós, Raúl

2014-12-31

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

Children's Perception of Gap Affordances: Bicycling Across Traffic-Filled Intersections in an Immersive Virtual Environment

Science.gov (United States)

Plumert, Jodie M.; Kearney, Joseph K.; Cremer, James F.

2004-01-01

This study examined gap choices and crossing behavior in children and adults using an immersive, interactive bicycling simulator. Ten- and 12-year-olds and adults rode a bicycle mounted on a stationary trainer through a virtual environment consisting of a street with 6 intersections. Participants faced continuous cross traffic traveling at 25mph…

14 CFR 33.49 - Endurance test.

Science.gov (United States)

2010-01-01

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

14 CFR 33.87 - Endurance test.

Science.gov (United States)

2010-01-01

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

Ergonomic Analysis of UI’s BicyclesUsing Posture Evaluation Index (PEI Method in Virtual Environment

Directory of Open Access Journals (Sweden)

Erlinda Muslim

2010-10-01

Full Text Available This research was conducted to study ergonomic aspect from University of Indonesia bicycle in virtual environment. Software Jack 6.0 was used to analyze it. PEI was used as approach that integrated the results of three methods: Lower Back Analysis, Ovako Working Posture Analysis, and Rapid Upper Limb Assessment. The research objective is to evaluate existing design of University of Indonesia bicycle and to determine the most ergonomic redesign which concern with handlebar height and saddle height modification. The result showed that the most ergonomic design of University of Indonesia bicycle is the one with the highest handlebar height (22 cm and the lowest saddle height (11 cm.

Severe bicycling injury risk factors in children and adolescents: a case-control study.

Science.gov (United States)

Hagel, Brent E; Romanow, Nicole T R; Enns, Nancy; Williamson, Jacqueline; Rowe, Brian H

2015-05-01

Bicycling is the most common cause of sports and recreation injury in children and adolescents; yet, there is limited evidence on the factors associated with severe bicycling injuries in youth. Case-control study of injured bicyclists less than 18 years old seen in seven emergency departments (EDs) from May 2008 to October 2010. Cases were bicyclists hospitalized after their ED visit (severe injury). Controls were bicyclists seen and discharged from the ED (non-severe injury). Personal, environmental, and crash characteristics were collected by interview. Injury data were collected from medical charts. Crude and adjusted odds ratios (ORs) and 95% confidence intervals (CIs) from logistic regression were used to estimate the odds of hospitalization associated with risk factors. Multiple imputation techniques were employed to address missing data. There were 1470 participants including 119 cases. Those ages 13-17 had the highest proportion (23%) of severe injuries resulting from motor vehicle [MV] collision. In models including age, sex and MV collision, being male (OR: 2.02; 95% CI: 1.21-3.38), not wearing a helmet (OR: 2.18; 95% CI: 1.43-3.31) and MV collision (OR: 3.91; 95% CI: 2.26-6.78) were significant risk factors for severe injury. Riding on a paved surface (OR: 0.63; 95% CI: 0.41-0.97) and utilitarian (school, work) bicycling (OR: 0.44; 95% CI: 0.2-0.94) decreased injury risk. Results were similar, apart from utilitarian bicycling (OR: 0.49; 95% CI: 0.22-1.06), after imputation for missing data. Bicycle-MV collisions increase severe injury risk in youth, and adolescents are often injured in these events. This suggests separating bicyclists from MVs or traffic calming strategies could improve safety. Copyright © 2015 Elsevier Ltd. All rights reserved.

Exploring the Chemistry of Bicyclic Isoxazolidines for the Multicomponent Synthesis of Glycomimetic Building Blocks.

Science.gov (United States)

Hoogenboom, Jorin; Lutz, Martin; Zuilhof, Han; Wennekes, Tom

2016-10-07

Starting from a chiral furanone, the nitrone-olefin [3 + 2] cycloaddition can be used to obtain bicyclic isoxazolidines for which we report a set of reactions to selectively modify each functional position. These synthetically versatile bicyclic isoxazolidines allowed us to obtain complex glycomimetic building blocks, like iminosugars, via multicomponent chemistry. For example, a library of 20 pipecolic acid derivatives, a recurring motif in various prescription drugs, could be obtained via a one-pot Staudinger/aza-Wittig/Ugi three-component reaction of a bicyclic isoxazolidine-derived azido-hemiacetal. Notably, specific pipecolic acids in this library were obtained via hydrolysis of an unique tricyclic imidate side product of the Ugi reaction. The azido-hemiacetal was also converted into an aza-C-glycoside iminosugar via an unprecendented one-pot Staudinger/aza-Wittig/Mannich reaction.

14 CFR 35.39 - Endurance test.

Science.gov (United States)

2010-01-01

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

Device and method to determine perineal artery occlusion during road bicycling.

Science.gov (United States)

Parthiban, Sujeeth; Hotaling, James M; Ohlander, Samuel J; Baftiri, Amit P; Freels, Sally; Niederberger, Craig S

2014-01-01

Greater than 60 million American men who ride bicycles are at risk of developing erectile dysfunction. One possible reason is occlusion of the perineal arteries. Researchers relied on indirect methods and stationary models to study this problem. We developed a novel system to quantify occlusion among bicycle riders during a road bike ride. Our verification and validation activities show that this system can be safely used on human subjects to measure perineal artery occlusion. The method described in this paper provides a valuable tool to the researchers to study or to develop new solutions that alleviate this problem. The outcomes of these efforts will help millions of cyclists worldwide.

Bicycle Facilities That Address Safety, Crime, and Economic Development: Perceptions from Morelia, Mexico

Directory of Open Access Journals (Sweden)

Inés Alveano-Aguerrebere

2017-12-01

Full Text Available México is a developing nation and, in the city of Morelia, the concept of the bicyclist as a road user appeared only recently in the Municipal Traffic Regulations. Perhaps the right bicycle infrastructure could address safety, crime, and economic development. To identify the best infrastructure, six groups in Morelia ranked and commented on pictures of bicycle environments that exist in bicycle-friendly nations. Perceptions about bike paths, but only those with impossible-to-be-driven-over solid barriers, were associated with safety from crashes, lowering crime, and contributing to economic development. Shared use paths were associated with lowering the probability of car/bike crashes but lacked the potential to deter crime and foster the local economy. Joint bus and bike lanes were associated with lower safety because of the unwillingness by Mexican bus drivers to be courteous to bicyclists. Gender differences about crash risk biking in the road with the cars (6 best/0 worst scenario were statistically significant (1.4 for male versus 0.69 for female; p < 0.001. For crashes, crime, and economic development, perceptions about bicycle infrastructure were different in this developing nation perhaps because policy, institutional context, and policing (ticketing for unlawful parking are not the same as in a developed nation. Countries such as Mexico should consider building cycle tracks with solid barriers to address safety, crime, and economic development.

Bicycle Facilities That Address Safety, Crime, and Economic Development: Perceptions from Morelia, Mexico

Science.gov (United States)

Alveano-Aguerrebere, Inés; Farvid, Maryam; Lusk, Anne

2017-01-01

México is a developing nation and, in the city of Morelia, the concept of the bicyclist as a road user appeared only recently in the Municipal Traffic Regulations. Perhaps the right bicycle infrastructure could address safety, crime, and economic development. To identify the best infrastructure, six groups in Morelia ranked and commented on pictures of bicycle environments that exist in bicycle-friendly nations. Perceptions about bike paths, but only those with impossible-to-be-driven-over solid barriers, were associated with safety from crashes, lowering crime, and contributing to economic development. Shared use paths were associated with lowering the probability of car/bike crashes but lacked the potential to deter crime and foster the local economy. Joint bus and bike lanes were associated with lower safety because of the unwillingness by Mexican bus drivers to be courteous to bicyclists. Gender differences about crash risk biking in the road with the cars (6 best/0 worst scenario) were statistically significant (1.4 for male versus 0.69 for female; p < 0.001). For crashes, crime, and economic development, perceptions about bicycle infrastructure were different in this developing nation perhaps because policy, institutional context, and policing (ticketing for unlawful parking) are not the same as in a developed nation. Countries such as Mexico should consider building cycle tracks with solid barriers to address safety, crime, and economic development. PMID:29271873

Bicycle Facilities That Address Safety, Crime, and Economic Development: Perceptions from Morelia, Mexico.

Science.gov (United States)

Alveano-Aguerrebere, Inés; Javier Ayvar-Campos, Francisco; Farvid, Maryam; Lusk, Anne

2017-12-22

México is a developing nation and, in the city of Morelia, the concept of the bicyclist as a road user appeared only recently in the Municipal Traffic Regulations. Perhaps the right bicycle infrastructure could address safety, crime, and economic development. To identify the best infrastructure, six groups in Morelia ranked and commented on pictures of bicycle environments that exist in bicycle-friendly nations. Perceptions about bike paths, but only those with impossible-to-be-driven-over solid barriers, were associated with safety from crashes, lowering crime, and contributing to economic development. Shared use paths were associated with lowering the probability of car/bike crashes but lacked the potential to deter crime and foster the local economy. Joint bus and bike lanes were associated with lower safety because of the unwillingness by Mexican bus drivers to be courteous to bicyclists. Gender differences about crash risk biking in the road with the cars (6 best/0 worst scenario) were statistically significant (1.4 for male versus 0.69 for female; p < 0.001). For crashes, crime, and economic development, perceptions about bicycle infrastructure were different in this developing nation perhaps because policy, institutional context, and policing (ticketing for unlawful parking) are not the same as in a developed nation. Countries such as Mexico should consider building cycle tracks with solid barriers to address safety, crime, and economic development.

Using Smartphones to Collect Bicycle Travel Data in Texas

Science.gov (United States)

2012-08-08

Researchers believed that if smartphones could prove to be an effective tool for collecting bicycle travel data, the information could be used for aiding decision making as to what types of facilities users prefer and guiding decisions about future f...

preparation of bicyclic lactones using lewis acids catalyzed ene

African Journals Online (AJOL)

Administrator

The synthesis of the cis-fused bicyclic lactones relies extensively on the Lewis acid ... having an allylic hydrogen (an"ene") and a compound containing an electron .... observed that the lithium enolate obtained from 3-methyl-2(5H)- furanone ...

運動疫学研究の成果に基づく味の素におけるヘルスプロモーションの展開

OpenAIRE

長沼, 由紀子; 甲斐, 裕子; 熊谷, 秋三

2003-01-01

The purpose of the present study was to examine the relationship between endurance fitness level and the prevalence of hypertension, diabetes mellitus and dyslipidemia in Japanese men. The subjects were 906 Japanese men aged 19-60 years. Maximal oxygen uptake (VO2max) was predicted using a cycle ergometer as an index of endurance fitness. Subjects were classified into four groups; G1 (VO2max

Human calf muscular metabolism study with a home-made ergometer using 31P NMR spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Peynsaert, J; Achten, E; Claeys, E [Ghent University Hospital (Belgium); Rousseaux, M [Ghent University Hospital (Belgium). Dept. of Sport Medicine

1995-12-01

Phosphorus-31 NMR measurements were performed to examine the variations in the concentration of phosphate metabolites in calf muscle during exercise. Therefore, volunteers, installed in the supine position, were asked to push repetitively on the pedal of a home-made ergometer. The produced work and the changes in phosphorus containing metabolites were measured continuously. Correlations were made between the inorganic phosphate/phosphocreatine ratio and the cumulative work and between the intracellular pH and the cumulative work. The exercise protocol could be changed interactively with respect to the imposed initial pressure, the maximum pressure, the pressure increase per level and the time a certain level was held. The whole experiment could be graphically followed on-line. In the first stadium, the in vitro reproducibility of the ergometer was tested for different protocols. These tests revealed that, though the deviation in produced work was markedly the highest at high working pressures, the relative error never exceeded 3%. Consequently, the ex vitro reproducibility of the data was examined with the equipment placed in the scanner. Generally, same conclusions could be derived. In a next stage, the work will be synchronized with the biochemical data. Extreme precautions will be taken to examine each volunteer every time under the same physical and psychological conditions.

Human calf muscular metabolism study with a home-made ergometer using 31P NMR spectroscopy

International Nuclear Information System (INIS)

Peynsaert, J.; Achten, E.; Claeys, E. . Dept. of Magnetic Resonance; Rousseaux, M.

1995-01-01

Phosphorus-31 NMR measurements were performed to examine the variations in the concentration of phosphate metabolites in calf muscle during exercise. Therefore, volunteers, installed in the supine position, were asked to push repetitively on the pedal of a home-made ergometer. The produced work and the changes in phosphorus containing metabolites were measured continuously. Correlations were made between the inorganic phosphate/phosphocreatine ratio and the cumulative work and between the intracellular pH and the cumulative work. The exercise protocol could be changed interactively with respect to the imposed initial pressure, the maximum pressure, the pressure increase per level and the time a certain level was held. The whole experiment could be graphically followed on-line. In the first stadium, the in vitro reproducibility of the ergometer was tested for different protocols. These tests revealed that, though the deviation in produced work was markedly the highest at high working pressures, the relative error never exceeded 3%. Consequently, the ex vitro reproducibility of the data was examined with the equipment placed in the scanner. Generally, same conclusions could be derived. In a next stage, the work will be synchronized with the biochemical data. Extreme precautions will be taken to examine each volunteer every time under the same physical and psychological conditions

Effects of Beetroot Juice Supplementation on a 30-s High-Intensity Inertial Cycle Ergometer Test

Directory of Open Access Journals (Sweden)

Raul Domínguez

2017-12-01

Full Text Available Background: Beetroot juice (BJ is rich in inorganic nitrates and has proved effective at increasing blood nitric oxide (NO levels. When used as a supplement BJ has shown an ergogenic effect on cardiorespiratory resistance exercise modalities, yet few studies have examined its impact on high intensity efforts. Objective: To assess the effects of BJ intake on anaerobic performance in a Wingate test. Methods: Fifteen trained men (age 21.46 ± 1.72 years, height 1.78 ± 0.07 cm and weight 76.90 ± 8.67 kg undertook a 30-s maximum intensity test on an inertial cycle ergometer after drinking 70 mL of BJ (5.6 mmol NO3− or placebo. Results: Despite no impacts of BJ on the mean power recorded during the test, improvements were produced in peak power (6% (p = 0.034, average power 0–15 s (6.7% (p = 0.048 and final blood lactate levels (82.6% (p < 0.001, and there was a trend towards a shorter time taken to attain peak power (−8.4% (p = 0.055. Conclusions: Supplementation with BJ has an ergonomic effect on maximum power output and on average power during the first 15 s of a 30-s maximum intensity inertial cycle ergometer test.

Automatic Stabilization of a Riderless Bicycle using the Active Disturbance Rejection Control Approach

Directory of Open Access Journals (Sweden)

Mauro Baquero-Suárez

2017-12-01

Full Text Available This work proposes an ADRC (Active Disturbance Rejection Control strategy by disturbance extended observers to stabilize a moving riderless bicycle with a variant forward speed. Although the bicycle has an unstable and non-linear dynamics when in its upright position, which can be modeled as a LPV (Linear-Parameter-Varying system that depends on the forward speed, a simplified time-invariant and lumped-parameter model, with an nominal constant forward speed is used in the controller design. ADRC scheme groups discrepancies between the simplified model and the plant, with external disturbances into an equivalent additive unified disturbance signal at input, which is estimated via the observer and rejected through a linear control law. The effectiveness of this strategy is validated by a co-simulation between ADAMS and MATLAB, which exhibits a high performance and robustness in a virtual dynamic model of the bicycle, submitted to severe external disturbances and parameter variations.

Laboratory versus outdoor cycling conditions: differences in pedaling biomechanics.

Science.gov (United States)

Bertucci, William; Grappe, Frederic; Groslambert, Alain

2007-05-01

The aim of our study was to compare crank torque profile and perceived exertion between the Monark ergometer (818 E) and two outdoor cycling conditions: level ground and uphill road cycling. Seven male cyclists performed seven tests in seated position at different pedaling cadences: (a) in the laboratory at 60, 80, and 100 rpm; (b) on level terrain at 80 and 100 rpm; and (c) on uphill terrain (9.25% grade) at 60 and 80 rpm. The cyclists exercised for 1 min at their maximal aerobic power. The Monark ergometer and the bicycle were equipped with the SRM Training System (Schoberer, Germany) for the measurement of power output (W), torque (Nxm), pedaling cadence (rpm), and cycling velocity (kmxh-1). The most important findings of this study indicate that at maximal aerobic power the crank torque profiles in the Monark ergometer (818 E) were significantly different (especially on dead points of the crank cycle) and generate a higher perceived exertion compared with road cycling conditions.

Investigation of the role of bicyclic peroxy radicals in the oxidation mechanism of toluene.

Science.gov (United States)

Birdsall, Adam W; Andreoni, John F; Elrod, Matthew J

2010-10-07

The products of the primary OH-initiated oxidation of toluene were investigated using the turbulent flow chemical ionization mass spectrometry technique under different oxygen, NO, and initial OH radical concentrations as well as a range of total pressures. The bicyclic peroxy radical intermediate, a key proposed intermediate species in the Master Chemical Mechanism (MCM) for the atmospheric oxidation of toluene, was detected for the first time. The toluene oxidation mechanism was shown to have a strong oxygen concentration dependence, presumably due to the central role of the bicyclic peroxy radical in determining the stable product distribution at atmospheric oxygen concentrations. The results also suggest a potential role for bicyclic peroxy radical + HO(2) reactions at high HO(2)/NO ratios. These reactions are postulated to be a source of the inconsistencies between environmental chamber results and predictions from the MCM.

Assessing and Mapping of Road Surface Roughness based on GPS and Accelerometer Sensors on Bicycle-Mounted Smartphones

Science.gov (United States)

Shen, Jie; Wan, Mi; Shi, Jiafeng

2018-01-01

The surface roughness of roads is an essential road characteristic. Due to the employed carrying platforms (which are often cars), existing measuring methods can only be used for motorable roads. Until now, there has been no effective method for measuring the surface roughness of un-motorable roads, such as pedestrian and bicycle lanes. This hinders many applications related to pedestrians, cyclists and wheelchair users. In recognizing these research gaps, this paper proposes a method for measuring the surface roughness of pedestrian and bicycle lanes based on Global Positioning System (GPS) and accelerometer sensors on bicycle-mounted smartphones. We focus on the International Roughness Index (IRI), as it is the most widely used index for measuring road surface roughness. Specifically, we analyzed a computing model of road surface roughness, derived its parameters with GPS and accelerometers on bicycle-mounted smartphones, and proposed an algorithm to recognize potholes/humps on roads. As a proof of concept, we implemented the proposed method in a mobile application. Three experiments were designed to evaluate the proposed method. The results of the experiments show that the IRI values measured by the proposed method were strongly and positively correlated with those measured by professional instruments. Meanwhile, the proposed algorithm was able to recognize the potholes/humps that the bicycle passed. The proposed method is useful for measuring the surface roughness of roads that are not accessible for professional instruments, such as pedestrian and cycle lanes. This work enables us to further study the feasibility of crowdsourcing road surface roughness with bicycle-mounted smartphones. PMID:29562731

The Feasibility of Wood and its Derivatives as a Bicycle Frame Building Material

OpenAIRE

BRENT TAYLOR, NICHOLAS

2016-01-01

[EN] ABSTRACT Nicholas Brent Taylor: The Feasibility of Wood and its Derivatives as a Bicycle Frame Building Material The bicycle is often considered as one of the most important inventions of all time. In addition, it is the most efficient form of human transport in the world. It is non pollutant, uses no fuel other than human power and its carbon footprint is neutralised in a short time. Today, faced with the threat of global warming brought about by fossil fuels, countries such as De...

Real-time bicycle detection at signalized intersections using thermal imaging technology

Science.gov (United States)

Collaert, Robin

2013-02-01

More and more governments and authorities around the world are promoting the use of bicycles in cities, as this is healthy for the bicyclist and improves the quality of life in general. Safety and efficiency of bicyclists has become a major focus. To achieve this, there is a need for a smarter approach towards the control of signalized intersections. Various traditional detection technologies, such as video, microwave radar and electromagnetic loops, can be used to detect vehicles at signalized intersections, but none of these can consistently separate bikes from other traffic, day and night and in various weather conditions. As bikes should get a higher priority and also require longer green time to safely cross the signalized intersection, traffic managers are looking for alternative detection systems that can make the distinction between bicycles and other vehicles near the stop bar. In this paper, the drawbacks of a video-based approach are presented, next to the benefits of a thermal-video-based approach for vehicle presence detection with separation of bicycles. Also, the specific technical challenges are highlighted in developing a system that combines thermal image capturing, image processing and output triggering to the traffic light controller in near real-time and in a single housing.

A Study for Adjustable Riding Position of the Innovation Bicycle Design

Science.gov (United States)

Huang, Yu-Che; Huang, Tai-Shen

2018-04-01

This research is about the analysis and design of the user in a wheelchair use posture can be changed. So user can through different sitting posture changes to provide different needs, so the folding design patents for the existing data collection and classification, through the analysis of advantages and disadvantages, further to find the innovative design approach. Finally through the multi linkage mechanism system, change the seat, handlebars and rear position, provide different posture context. In order to reduce the cost, this study is designed to integrate the innovation input mechanism, multi linkage system, through the construction of 10 joints and degrees of freedom of the bicycle frame. Then use 3D software to design of bicycle the size of the frame of innovation, through the three-dimensional CAD model to simulate the mechanism between movement and interference, and to evaluate the 3D The virtual prototype can meet the requirement. It will also enable CAE to analyze and determine the strength and the safety of the bicycle frame structure of ANSYS11.0 stress. Finally, we have integrated design through CAID to make a product appearance, the focus of research is mainly a study of CAD, CAE, CAID integration the production and the completion of a prototype.

The Politics of Bicycle Innovation: Comparing the American and Dutch Human-Powered Vehicle Movements, 1970s—present

NARCIS (Netherlands)

Stoffers, M.; Oldenziel, R; Trischler, H

2016-01-01

This paper deals with the history of the international Human-Powered Vehicle (HPV) movement, originally launched in the 1970s by engineers and scientists who believed that bicycle innovation could give a major impetus to a coveted western bicycle renaissance. Based on a reading of magazines and

Perceiving and Acting on Complex Affordances: How Children and Adults Bicycle across Two Lanes of Opposing Traffic

Science.gov (United States)

Grechkin, Timofey Y.; Chihak, Benjamin J.; Cremer, James F.; Kearney, Joseph K.; Plumert, Jodie M.

2013-01-01

This investigation examined how children and adults negotiate a challenging perceptual-motor problem with significant real-world implications--bicycling across two lanes of opposing traffic. Twelve- and 14-year-olds and adults rode a bicycling simulator through an immersive virtual environment. Participants crossed intersections with continuous…

Street Intersection Characteristics and Their Impacts on Perceived Bicycling Safety

Science.gov (United States)

2018-01-01

Safety concern is one of the core issues that deter people from bicycling in the US. Earlier studies have explored the associations between intersection design characteristics and bicyclist safety perceptions. Research shows that there are significan...

Caffein

DEFF Research Database (Denmark)

Nørager, Charlotte Buchard; Jensen, Martin Bach; Madsen, Mogens Rørbæk

2005-01-01

/kg) can increase the endurance of athletes engaged in running, bicycling, swimming and other endurance sports. Caffeine is used both in training and in competitions, and the International Olympic Commitée (IOC) has included caffeine as a drug used for doping. There are several theories about caffeine...

An expert judgment model applied to estimating the safety effect of a bicycle facility.

Science.gov (United States)

Leden, L; Gårder, P; Pulkkinen, U

2000-07-01

This paper presents a risk index model that can be used for assessing the safety effect of countermeasures. The model estimates risk in a multiplicative way, which makes it possible to analyze the impact of different factors separately. Expert judgments are incorporated through a Bayesian error model. The variance of the risk estimate is determined by Monte-Carlo simulation. The model was applied to assess the safety effect of a new design of a bicycle crossing. The intent was to gain safety by raising the crossings to reduce vehicle speeds and by making the crossings more visible by painting them in a bright color. Before the implementations, bicyclists were riding on bicycle crossings of conventional Swedish type, i.e. similar to crosswalks but delineated by white squares rather than solid lines or zebra markings. Automobile speeds were reduced as anticipated. However, it seems as if the positive effect of this was more or less canceled out by increased bicycle speeds. The safety per bicyclist was still improved by approximately 20%. This improvement was primarily caused by an increase in bicycle flow, since the data show that more bicyclists at a given location seem to benefit their safety. The increase in bicycle flow was probably caused by the new layout of the crossings since bicyclists perceived them as safer and causing less delay. Some future development work is suggested. Pros and cons with the used methodology are discussed. The most crucial parameter to be added is probably a model describing the interaction between motorists and bicyclists, for example, how risk is influenced by the lateral position of the bicyclist in relation to the motorist. It is concluded that the interaction seems to be optimal when both groups share the roadway.

The Comparison of Two Methods of Exercise (intense interval training and concurrent resistance- endurance training on Fasting Sugar, Insulin and Insulin Resistance in Women with Mellitus Diabetes

Directory of Open Access Journals (Sweden)

F Bazyar

2016-05-01

Full Text Available Background & aim: Exercise is an important component of health and an integral approach to the management of diabetes mellitus. The purpose of this study was to compare the effects of intense interval training and concurrent resistance- endurance training on fasting sugar, insulin and insulin resistance in women with mellitus diabetes.   Methods: Fifty-two overweight female diabetic type 2 patients (aged 45-60 years old with fasting blood glucose≥ 126 mg/dl were selected to participate in the present study. Participants were assigned to intense interval training group (N=17, concurrent resistance- endurance training group (N=17 and control group (N=18. The exercises incorporated 10 weeks of concurrent resistance- endurance training and intense interval training. Fasting blood sugar, serum insulin concentrations levels were measured. Concurrent training group trained eight weeks, three times a week of endurance training at 60% of maximum heart rate (MHR and two resistance training sessions per week with 70% of one repetition maximum (1-RM. Intense interval training group trained for eight weeks, three sessions per week for 4 to 10 repeats Wingate test on the ergometer 30s performed with maximum effort. The control group did no systematic exercise. At the end of experiment 42 subjects were succeed and completed the study period, and 10 subjects were removed due to illness and absence in the exercise sessions. Fasting blood sugar and insulin levels 24 hours before and 48 hours after the last training session was measured.   Results: The findings indicated that in periodic fasting, the blood sugar in intensive training group had a marked decrease (p= 0.000 however, the fasting blood sugar of exercise and power stamina groups reduced significantly (p=0.062. The results showed no significant difference between the groups (171/0 p =0.171. Fasting insulin (p <0.001 and insulin resistance (0001/0 = p=0.001 in periodic intensive training group were

Validity of a Newly-Designed Rectilinear Stepping Ergometer Submaximal Exercise Test to Assess Cardiorespiratory Fitness

OpenAIRE

Rubin Zhang, Likui Zhan, Shaoming Sun, Wei Peng, Yining Sun

2017-01-01

The maximum oxygen uptake (V̇O2 max), determined from graded maximal or submaximal exercise tests, is used to classify the cardiorespiratory fitness level of individuals. The purpose of this study was to examine the validity and reliability of the YMCA submaximal exercise test protocol performed on a newly-designed rectilinear stepping ergometer (RSE) that used up and down reciprocating vertical motion in place of conventional circular motion and giving precise measurement of workload, to det...

Structural design of a composite bicycle fork

International Nuclear Information System (INIS)

Baldissera, Paolo; Delprete, Cristiana

2014-01-01

Highlights: • Case study about composite bicycle fork design. • Special requirements for a Student Team project. • FE model to evaluate stiffness, strength and potential failure modes. • Comparison of two manufacturing approaches. • FE model stiffness validation on the manufactured fork. - Abstract: Despite the wide literature on the mechanical behaviour of carbon/epoxy composites, it is rare to find practical methodological approaches in finite element design of structural components made by laminate layup. Through the case study of a special bicycle fork needed in a Student Team prototype, this paper proposes a simplified methodology as starting point for educational and manufacturing purposes. In order to compare two manufacturing solutions in terms of stiffness, strength and failure mode, a numerical model was implemented. Since the project requirements imposed to avoid standard destructive testing, the model validation was based on a posteriori linear stiffness comparison with the manufactured component. The slight discrepancies between experimental and numerical results were discussed in order to check their origin and to assess the reliability of the model. The overall methodology, even if complain with only a part of the safety standard requirements, shows to be reliable enough and can be the basis for further extension and refinement

Efficiency of choice set generation methods for bicycle routes

DEFF Research Database (Denmark)

Halldórsdóttir, Katrín; Rieser-Schussler, Nadine; Axhausen, Kay W.

2014-01-01

for scenic routes, dedicated cycle lanes, and road type. Data consisted of 778 bicycle trips traced by GPS and carried out by 139 persons living in the Greater Copenhagen Area, in Denmark. Results suggest that both the breadth first search on link elimination and the doubly stochastic generation function...

Methodological proposal for the implementation of shared bicycle applied to the Brazilian context

Energy Technology Data Exchange (ETDEWEB)

Espana, J.P.; Barbosa, P.

2016-07-01

The main objective of this study is to analyze the bicycle rental system in the Federal District {sup B}ike Brasilia{sup .} It aims to identify guidelines that supported the application process and consensus, disagreements and guidelines established by the Institute for Policies and Development in Transportation - ITDP and relate those listed by Zhang regarding rented bikes systems. This is an exploratory study based on the strategy of document analysis and its secondary sources: institutional documents, basic design, procurement and other official documents made exclusively for this study. To support the discussion, a systematic literature review of the rules describing specially: sustainability, transport, urban mobility, bicycle rental and environment. The results reveal that while some of the parameters and indicators of efficiency are met on time, the bicycle sharing system of the city of Brasilia, has weaknesses that can lead to inefficiency and impracticality of maintaining and expanding such services. On the other hand, Bike Brasilia partially fulfills the principles enumerated by Zhang and lacks improvement in the steps for the successful operation of the system. (Author)

Peptides derivatized with bicyclic quaternary ammonium ionization tags. Sequencing via tandem mass spectrometry.

Science.gov (United States)

Setner, Bartosz; Rudowska, Magdalena; Klem, Ewelina; Cebrat, Marek; Szewczuk, Zbigniew

2014-10-01

Improving the sensitivity of detection and fragmentation of peptides to provide reliable sequencing of peptides is an important goal of mass spectrometric analysis. Peptides derivatized by bicyclic quaternary ammonium ionization tags: 1-azabicyclo[2.2.2]octane (ABCO) or 1,4-diazabicyclo[2.2.2]octane (DABCO), are characterized by an increased detection sensitivity in electrospray ionization mass spectrometry (ESI-MS) and longer retention times on the reverse-phase (RP) chromatography columns. The improvement of the detection limit was observed even for peptides dissolved in 10 mM NaCl. Collision-induced dissociation tandem mass spectrometry of quaternary ammonium salts derivatives of peptides showed dominant a- and b-type ions, allowing facile sequencing of peptides. The bicyclic ionization tags are stable in collision-induced dissociation experiments, and the resulted fragmentation pattern is not significantly influenced by either acidic or basic amino acid residues in the peptide sequence. Obtained results indicate the general usefulness of the bicyclic quaternary ammonium ionization tags for ESI-MS/MS sequencing of peptides. Copyright © 2014 John Wiley & Sons, Ltd.

The usefulness of GPS bicycle tracking data for evaluating the impact of infrastructure change on cycling behaviour.

Science.gov (United States)

Heesch, Kristiann C; Langdon, Michael

2016-02-01

Issue addressed A key strategy to increase active travel is the construction of bicycle infrastructure. Tools to evaluate this strategy are limited. This study assessed the usefulness of a smartphone GPS tracking system for evaluating the impact of this strategy on cycling behaviour. Methods Cycling usage data were collected from Queenslanders who used a GPS tracking app on their smartphone from 2013-2014. 'Heat' and volume maps of the data were reviewed, and GPS bicycle counts were compared with surveillance data and bicycle counts from automatic traffic-monitoring devices. Results Heat maps broadly indicated that changes in cycling occurred near infrastructure improvements. Volume maps provided changes in counts of cyclists due to these improvements although errors were noted in geographic information system (GIS) geo-coding of some GPS data. Large variations were evident in the number of cyclists using the app in different locations. These variations limited the usefulness of GPS data for assessing differences in cycling across locations. Conclusion Smartphone GPS data are useful in evaluating the impact of improved bicycle infrastructure in one location. Using GPS data to evaluate differential changes in cycling across multiple locations is problematic when there is insufficient traffic-monitoring devices available to triangulate GPS data with bicycle traffic count data. So what? The use of smartphone GPS data with other data sources is recommended for assessing how infrastructure improvements influence cycling behaviour.

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

Science.gov (United States)

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

2017-03-01

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

Physical activity and the elderly.

Science.gov (United States)

Hollmann, Wildor; Strüder, Heiko K; Tagarakis, Christos V M; King, Gerard

2007-12-01

Functional ageing processes are characterized by a loss of performance capabilities regarding coordination, flexibility, strength, speed, and endurance. The effects of ageing processes on the cardiovascular system and skeletal muscle are the foci of attention. After age 30, the maximum aerobic dynamic performance capacity decreases by an average of 8% per decade. The causes are mainly a reduction in the maximum cardiac output and decreases in capillarization and in the skeletal muscle mass. An improvement in the maximum oxygen uptake by 18% and in the aerobic-anaerobic threshold by 22% was achieved in untrained men aged 55-70 years, in a 12-week-long bicycle ergometer-training programme. The strength of the skeletal muscle decreases particularly after 50-60 years of age. The main cause is the reduction in the number of motor units and muscle fibres. Further, modifications of the endothelial function and the development of sarcopenia are of particular importance in ageing processes. General aerobic dynamic training can improve the endothelial function in old age and thus help prevent cardiovascular diseases. Strength training is most appropriate for the prevention of sarcopenia. Imaging techniques over the last 20 years have provided new findings on the influence and the significance of physical activity on the brain. We call this new interdisciplinary area 'Exercise Neuroscience'. Demands on coordination and aerobic dynamic endurance are suitable in counteracting age-related neuronal cellular loss, synapsis hypotrophy, and in improving neurogenesis and capillarization. Adjusted physical activity is thus capable of counteracting age-related changes and performance loss not only in the cardiovascular system but also in the brain.

High-intensity interval training improves insulin sensitivity in older individuals.

Science.gov (United States)

Søgaard, D; Lund, M T; Scheuer, C M; Dehlbaek, M S; Dideriksen, S G; Abildskov, C V; Christensen, K K; Dohlmann, T L; Larsen, S; Vigelsø, A H; Dela, F; Helge, J W

2018-04-01

Metabolic health may deteriorate with age as a result of altered body composition and decreased physical activity. Endurance exercise is known to counter these changes delaying or even preventing onset of metabolic diseases. High-intensity interval training (HIIT) is a time efficient alternative to regular endurance exercise, and the aim of this study was to investigate the metabolic benefit of HIIT in older subjects. Twenty-two sedentary male (n = 11) and female (n = 11) subjects aged 63 ± 1 years performed HIIT training three times/week for 6 weeks on a bicycle ergometer. Each HIIT session consisted of five 1-minute intervals interspersed with 1½-minute rest. Prior to the first and after the last HIIT session whole-body insulin sensitivity, measured by a hyperinsulinaemic-euglycaemic clamp, plasma lipid levels, HbA1c, glycaemic parameters, body composition and maximal oxygen uptake were assessed. Muscle biopsies were obtained wherefrom content of glycogen and proteins involved in muscle glucose handling were determined. Insulin sensitivity (P = .011) and maximal oxygen uptake increased (P body fat (P < .05) decreased after 6 weeks of HIIT. HbA1c decreased only in males (P = .001). Muscle glycogen content increased in both genders (P = .001) and in line GLUT4 (P < .05), glycogen synthase (P = .001) and hexokinase II (P < .05) content all increased. Six weeks of HIIT significantly improves metabolic health in older males and females by reducing age-related risk factors for cardiometabolic disease. © 2017 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

Metabolic Responses to Sago and Soy Supplementations during Endurance Cycling Performance in the Heat

Directory of Open Access Journals (Sweden)

Daniel Tarmast

2017-10-01

Full Text Available This study examined the effects of Sago (Sa, Soy (So, combined iso–caloric Sago+Soy (SS supplementations during cycling on metabolic responses as compared to placebo (P in the heat (31℃, 70% relative humidity. Twelve well–trained male cyclists (Age: 19.0±5.6 yr, Height: 170.8±7.6 cm, Wight: 60.1±11.2 kg, and VO2max: 56.5±6.5 mL.kg-1.min-1 participated in four experimental trials. The design of the trials was a randomized single–blind, placebo–controlled crossover trail comprising 90 min of steady–state cycling on an ergometer at 60% of VO2max followed by a 20–km time trial performance (TT. The participants of the study were supplemented 5 times at 0, 20, 40, 60, and 80 minutes during the steady–state cycling. Sa, So, and SS supplements provided 7.5% Sago, 7.5% Soy, and 6.0% Sago + 1.5% Soy respectively. Plasma glucose concentrations (PG reached a peak at 60 min after ingestion of Sa and SS as compared to baseline. At the end of the TT, PG reduced significantly to the baseline level. Plasma insulin concentrations (PI increased in all trials, but reduced gradually to the baseline level. The concentration of plasma free fatty acids (FFA increased gradually during the steady–state cycling and TT, and FFA was significantly higher in the P and So than the Sa and SS trials. At the end of the steady–state cycling, the plasma lactate concentration (LACT reached its lowest concentrations and at the end of the TT was enhanced significantly in all trials. These results suggest that sago and soy supplements increase the PG and PI during endurance exercise in the heat. These data add to the growing body of knowledge concerning endurance athletes’ glycemic and insulinemic responses to carbohydrate consumptions during exercise in the heat.

An experiment on rider stability while mounting : comparing middle-aged and elderly cyclists on pedelecs and conventional bicycles.

NARCIS (Netherlands)

Twisk, D.A.M. Platteel, S. & Lovegrove, G.R.

2017-01-01

Pedelecs, popular among elderly cyclists, are associated with a higher injury risk than conventional bicycles. About 17% of these injuries are due to falls while (dis)mounting. Using instrumented bicycles, this study aimed to identify factors contributing to the stability of self-chosen mounting

Acute-Phase Inflammatory Response to Single-Bout HIIT and Endurance Training: A Comparative Study

Directory of Open Access Journals (Sweden)

Felix Kaspar

2016-01-01

Full Text Available Objective. This study compared acute and late effect of single-bout endurance training (ET and high-intensity interval training (HIIT on the plasma levels of four inflammatory cytokines and C-reactive protein and insulin-like growth factor 1. Design. Cohort study with repeated-measures design. Methods. Seven healthy untrained volunteers completed a single bout of ET and HIIT on a cycle ergometer. ET and HIIT sessions were held in random order and at least 7 days apart. Blood was drawn before the interventions and 30 min and 2 days after the training sessions. Plasma samples were analyzed with ELISA for the interleukins (IL, IL-1β, IL-6, and IL-10, monocyte chemoattractant protein-1 (MCP-1, insulin growth factor 1 (IGF-1, and C-reactive protein (CRP. Statistical analysis was with Wilcoxon signed-rank tests. Results. ET led to both a significant acute and long-term inflammatory response with a significant decrease at 30 minutes after exercise in the IL-6/IL-10 ratio (−20%; p=0.047 and a decrease of MCP-1 (−17.9%; p=0.03. Conclusion. This study demonstrates that ET affects the inflammatory response more adversely at 30 minutes after exercise compared to HIIT. However, this is compensated by a significant decrease in MCP-1 at two days associated with a reduced risk of atherosclerosis.

Acute-Phase Inflammatory Response to Single-Bout HIIT and Endurance Training: A Comparative Study

Science.gov (United States)

Kaspar, Felix; Jelinek, Herbert F.; Perkins, Steven; Al-Aubaidy, Hayder A.; deJong, Bev; Butkowski, Eugene

2016-01-01

Objective. This study compared acute and late effect of single-bout endurance training (ET) and high-intensity interval training (HIIT) on the plasma levels of four inflammatory cytokines and C-reactive protein and insulin-like growth factor 1. Design. Cohort study with repeated-measures design. Methods. Seven healthy untrained volunteers completed a single bout of ET and HIIT on a cycle ergometer. ET and HIIT sessions were held in random order and at least 7 days apart. Blood was drawn before the interventions and 30 min and 2 days after the training sessions. Plasma samples were analyzed with ELISA for the interleukins (IL), IL-1β, IL-6, and IL-10, monocyte chemoattractant protein-1 (MCP-1), insulin growth factor 1 (IGF-1), and C-reactive protein (CRP). Statistical analysis was with Wilcoxon signed-rank tests. Results. ET led to both a significant acute and long-term inflammatory response with a significant decrease at 30 minutes after exercise in the IL-6/IL-10 ratio (−20%; p = 0.047) and a decrease of MCP-1 (−17.9%; p = 0.03). Conclusion. This study demonstrates that ET affects the inflammatory response more adversely at 30 minutes after exercise compared to HIIT. However, this is compensated by a significant decrease in MCP-1 at two days associated with a reduced risk of atherosclerosis. PMID:27212809

Acute-Phase Inflammatory Response to Single-Bout HIIT and Endurance Training: A Comparative Study.

Science.gov (United States)

Kaspar, Felix; Jelinek, Herbert F; Perkins, Steven; Al-Aubaidy, Hayder A; deJong, Bev; Butkowski, Eugene

2016-01-01

This study compared acute and late effect of single-bout endurance training (ET) and high-intensity interval training (HIIT) on the plasma levels of four inflammatory cytokines and C-reactive protein and insulin-like growth factor 1. Cohort study with repeated-measures design. Seven healthy untrained volunteers completed a single bout of ET and HIIT on a cycle ergometer. ET and HIIT sessions were held in random order and at least 7 days apart. Blood was drawn before the interventions and 30 min and 2 days after the training sessions. Plasma samples were analyzed with ELISA for the interleukins (IL), IL-1β, IL-6, and IL-10, monocyte chemoattractant protein-1 (MCP-1), insulin growth factor 1 (IGF-1), and C-reactive protein (CRP). Statistical analysis was with Wilcoxon signed-rank tests. ET led to both a significant acute and long-term inflammatory response with a significant decrease at 30 minutes after exercise in the IL-6/IL-10 ratio (-20%; p = 0.047) and a decrease of MCP-1 (-17.9%; p = 0.03). This study demonstrates that ET affects the inflammatory response more adversely at 30 minutes after exercise compared to HIIT. However, this is compensated by a significant decrease in MCP-1 at two days associated with a reduced risk of atherosclerosis.

A combination of routine blood analytes predicts fitness decrement in elderly endurance athletes.

Directory of Open Access Journals (Sweden)

Helmuth Haslacher

Full Text Available Endurance sports are enjoying greater popularity, particularly among new target groups such as the elderly. Predictors of future physical capacities providing a basis for training adaptations are in high demand. We therefore aimed to estimate the future physical performance of elderly marathoners (runners/bicyclists using a set of easily accessible standard laboratory parameters. To this end, 47 elderly marathon athletes underwent physical examinations including bicycle ergometry and a blood draw at baseline and after a three-year follow-up period. In order to compile a statistical model containing baseline laboratory results allowing prediction of follow-up ergometry performance, the cohort was subgrouped into a model training (n = 25 and a test sample (n = 22. The model containing significant predictors in univariate analysis (alanine aminotransferase, urea, folic acid, myeloperoxidase and total cholesterol presented with high statistical significance and excellent goodness of fit (R2 = 0.789, ROC-AUC = 0.951±0.050 in the model training sample and was validated in the test sample (ROC-AUC = 0.786±0.098. Our results suggest that standard laboratory parameters could be particularly useful for predicting future physical capacity in elderly marathoners. It hence merits further research whether these conclusions can be translated to other disciplines or age groups.

The PurdueTracer: An Energy-Efficient Human-Powered Hydraulic Bicycle with Flexible Operation and Software Aids

Directory of Open Access Journals (Sweden)

Gianluca Marinaro

2018-01-01

Full Text Available Hydrostatic transmissions (HT are widely applied to heavy-duty mobile applications because of the advantages of layout flexibility, power to weight ratio, and ease of control. Though applications of fluid power in light-duty vehicles face challenges, including the unavailability of off-the-shelf components suitable to the power scale, there are potential advantages for HTs in human-powered vehicles, such as bicycles, the most important one being the energy-saving advantage achievable through regenerative braking in a hybrid HT. This paper describes an innovative design for a hydraulic hybrid bicycle, i.e., the PurdueTracer. The PurdueTracer is an energy-efficient human-powered hydraulic bicycle with flexible operation and software aids. An open-circuit hydraulic hybrid transmission allows PurdueTracer to operate in four modes: Pedaling, Charging, Boost, and Regeneration, to satisfy users’ need for different riding occasions. An aluminum chassis that also functions as a system reservoir was customized for the PurdueTracer to optimize the durability, riding comfort, and space for components. The selection of the hydraulic components was performed by creating a model of the bicycle in AMESim simulation software and conducting a numerical optimization based on the model. The electronic system equipped users with informative feedback showing the bicycle performance, intuitive execution of functions, and comprehensive guidance for operation. This paper describes the design approach and the main results of the PurdueTracer, which also won the 2017 National Fluid Power Association Fluid Power Vehicle Challenge. This championship serves to prove the excellence of this vehicle in terms of effectiveness, efficiency, durability, and novelty.

Synthesis and anticonvulsant activity of novel bicyclic acidic amino acids

DEFF Research Database (Denmark)

Conti, Paola; De Amici, Marco; Joppolo Di Ventimiglia, Samuele

2003-01-01

Bicyclic acidic amino acids (+/-)-6 and (+/-)-7, which are conformationally constrained homologues of glutamic acid, were prepared via a strategy based on a 1,3-dipolar cycloaddition. The new amino acids were tested toward ionotropic and metabotropic glutamate receptor subtypes; both of them...

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

Science.gov (United States)

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

2015-01-01

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

Exhaled methane concentration profiles during exercise on an ergometer

Science.gov (United States)

Szabó, A; Ruzsanyi, V; Unterkofler, K; Mohácsi, Á; Tuboly, E; Boros, M; Szabó, G; Hinterhuber, H; Amann, A

2016-01-01

Exhaled methane concentration measurements are extensively used in medical investigation of certain gastrointestinal conditions. However, the dynamics of endogenous methane release is largely unknown. Breath methane profiles during ergometer tests were measured by means of a photoacoustic spectroscopy based sensor. Five methane-producing volunteers (with exhaled methane level being at least 1 ppm higher than room air) were measured. The experimental protocol consisted of 5 min rest—15 min pedalling (at a workload of 75 W)—5 min rest. In addition, hemodynamic and respiratory parameters were determined and compared to the estimated alveolar methane concentration. The alveolar breath methane level decreased considerably, by a factor of 3–4 within 1.5 min, while the estimated ventilation-perfusion ratio increased by a factor of 2–3. Mean pre-exercise and exercise methane concentrations were 11.4 ppm (SD:7.3) and 2.8 ppm (SD:1.9), respectively. The changes can be described by the high sensitivity of exhaled methane to ventilationperfusion ratio and are in line with the Farhi equation. PMID:25749807

Usage Patterns of Electric Bicycles: An Analysis of the WeBike Project

Directory of Open Access Journals (Sweden)

Christian Gorenflo

2017-01-01

Full Text Available This paper presents an analysis of data collected through the Waterloo WeBike project: a field trial in which over 30 sensor-equipped electric bicycles (e-bikes were given to members of the University of Waterloo for personal use. Our dataset includes e-bike trips and battery charging sessions spanning nearly three years, from summer 2014 until spring 2017. We also conducted three surveys both before and during the trial. Our main findings were that the primary purpose of the e-bikes in our trial was for commuting, with most trips lasting less than 20 minutes and most trips taking place in the summer months. Our battery charging analysis revealed no evidence of range anxiety, and our analysis of survey results showed little correlation between anticipated and actual use. Furthermore, when asked about their opinions about various modes of transportation, our participants rated regular bicycles higher than e-bikes even after becoming familiar with e-bikes through the field trial. Based on our analysis, we draw several conclusions, including the fact that the general population in Canada is still unaware of e-bikes and their potential. Moreover, e-bike manufacturers should target sales to nonbike users, such as seniors, rather than trying to displace sales of regular bicycles.

Municipal investment in off-road trails and changes in bicycle commuting in Minneapolis, Minnesota over 10 years: a longitudinal repeated cross-sectional study.

Science.gov (United States)

Hirsch, Jana A; Meyer, Katie A; Peterson, Marc; Zhang, Le; Rodriguez, Daniel A; Gordon-Larsen, Penny

2017-02-13

We studied the effect of key development and expansion of an off-road multipurpose trail system in Minneapolis, Minnesota between 2000 and 2007 to understand whether infrastructure investments are associated with increases in commuting by bicycle. We used repeated measures regression on tract-level (N = 116 tracts) data to examine changes in bicycle commuting between 2000 and 2008-2012. We investigated: 1) trail proximity measured as distance from the trail system and 2) trail potential use measured as the proportion of commuting trips to destinations that might traverse the trail system. All analyses (performed 2015-2016) adjusted for tract-level sociodemographic covariates and contemporaneous cycling infrastructure changes (e.g., bicycle lanes). Tracts that were both closer to the new trail system and had a higher proportion of trips to destinations across the trail system experienced greater 10-year increases in commuting by bicycle. Proximity to off-road infrastructure and travel patterns are relevant to increased bicycle commuting, an important contributor to overall physical activity. Municipal investment in bicycle facilities, especially off-road trails that connect a city's population and its employment centers, is likely to lead to increases in commuting by bicycle.

The effect of a yellow bicycle jacket on cyclist accidents

DEFF Research Database (Denmark)

Lahrmann, Harry; Madsen, Tanja Kidholm Osmann; Olesen, Anne Vingaard

2018-01-01

Highlights •A randomised controlled trial with 6793 cyclists shows a reduced accident risk due to a yellow bicycle jacket. •The test group had 47% fewer multiparty accidents with personal injury. •The test group had 55% fewer multiparty accidents against motorised vehicles....

Nutritional Supplements for Endurance Athletes

Science.gov (United States)

Rasmussen, Christopher J.

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

Cycle ergometer and inspiratory muscle training offer modest benefit compared with cycle ergometer alone: a comprehensive assessment in stable COPD patients

Directory of Open Access Journals (Sweden)

Wang K

2017-09-01

Full Text Available Kai Wang,1,* Guang-qiao Zeng,2,* Rui Li,1,* Yu-wen Luo,1 Mei Wang,1 Yu-he Hu,1 Wen-hui Xu,1 Lu-qian Zhou,2 Rong-chang Chen,2 Xin Chen1 1Department of Respiratory Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, China; 2Department of Respiratory Medicine, The State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, Guangzhou Institute of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China *These authors contributed equally to this work Background: Cycle ergometer training (CET has been shown to improve exercise performance of the quadriceps muscles in patients with COPD, and inspiratory muscle training (IMT may improve the pressure-generating capacity of the inspiratory muscles. However, the effects of combined CET and IMT remain unclear and there is a lack of comprehensive assessment.Materials and methods: Eighty-one patients with COPD were randomly allocated to three groups: 28 received 8 weeks of CET + IMT (combined training group, 27 received 8 weeks of CET alone (CET group, and 26 only received 8 weeks of free walking (control group. Comprehensive assessment including respiratory muscle strength, exercise capacity, pulmonary function, dyspnea, quality of life, emotional status, nutritional status, and body mass index, airflow obstruction, and exercise capacity index were measured before and after the pulmonary rehabilitation program.Results: Respiratory muscle strength, exercise capacity, inspiratory capacity, dyspnea, quality of life, depression and anxiety, and nutritional status were all improved in the combined training and CET groups when compared with that in the control group (P<0.05 after pulmonary rehabilitation program. Inspiratory muscle strength increased significantly in the combined training group when compared with that in the CET group (ΔPImax [maximal inspiratory pressure] 5.20±0.89 cmH2O vs 1.32±0.91 cmH2O

More pronounced effect of acute exercise-induced increase in circulating inflammatory markers in obese compared to lean subjects

DEFF Research Database (Denmark)

Christiansen, Tore; Paulsen, Søren Kildeberg; Bruun, Jens Meldgaard

2010-01-01

in circulation, and on gene expression on these infammatory marker in skeletal muscle (SM) and adipose tissue (AT) biopsies. Material and Methods: 15 lean males and females (BMI 22.4±2 kg/m2) and 16 obese males and females (BMI 31.6±3 kg/m2) exercised for 120 minutes by ergometer bicycling at moderate intensity......Objective: Exercise modulates the immune system and in young males acute exercise has been found associated with increased systemic level of infam-matory markers such as IL-6 and IL-8. In this study we investigated the impact of obesity on the exercise induced release of infammatory markers...... (55-60% of maximal heart rate). Blood samples were obtained at baseline (T0), after 60 minutes of bicycling (T=60), after 120 minutes of bicycling (T=120), whereas biopsies from AT and SM were obtained at T0 and T120. Results: Divided into weight-status, plasma levels of IL-8 and TNFα were at T=120...

Hydrolysis of strained bridgehead bicyclic vinyl ethers and sulfides

International Nuclear Information System (INIS)

Chwang, W.K.; Kresge, A.J.; Wiseman, J.R.

1979-01-01

Rates of hydrolysis of the bridgehead bicyclic vinyl ether 9-oxabicyclo[3.3.1]non-1-ene(6) and its vinyl sulfide counterpart 9-thiabicyclo[3.3.1]non-1-ene(7), catalyzed by the hydronium ion, were measured in H 2 O and in D 2 O solution. These data give isotope effects, k/sub H//k/sub D/ = 2.4 and 1.9 respectively, which show that these reactions occur by the normal, rate-determining carbon protonation, mechanism. The vinyl ether 6 is less reactive than its olefin analogue, bicyclo[3.3.1]non-1-ene (relative rate 1:1/1400), as may have been expected for a constrained bicyclic system such as this, where stabilization of the bridgehead carbocation intermediate by conjugation with oxygen is severely impaired. The vinyl sulfide 7, however, is even less reactive than the vinyl ether (relative rates 1:1/140); this is a remarkable result in view of the fact that conjugation between the sulfur atom and the cationic center is presumably also strongly inhibited. 1 figure, 3 tables

Changes of heart rate variability and prefrontal oxygenation during Tai Chi practice versus arm ergometer cycling

OpenAIRE

Lu, Xi; Hui-Chan, Christina Wan-Ying; Tsang, William Wai-Nam

2016-01-01

[Purpose] Exercise has been shown to improve cardiovascular fitness and cognitive function. Whether the inclusion of mind over exercise would increase parasympathetic control of the heart and brain activities more than general exercise at a similar intensity is not known. The aim of this study was to compare the effects of Tai Chi (mind-body exercise) versus arm ergometer cycling (body-focused exercise) on the heart rate variability and prefrontal oxygenation level. [Subjects and Methods] A T...

Validity of a Newly-Designed Rectilinear Stepping Ergometer Submaximal Exercise Test to Assess Cardiorespiratory Fitness.

Science.gov (United States)

Zhang, Rubin; Zhan, Likui; Sun, Shaoming; Peng, Wei; Sun, Yining

2017-09-01

The maximum oxygen uptake (V̇O 2 max), determined from graded maximal or submaximal exercise tests, is used to classify the cardiorespiratory fitness level of individuals. The purpose of this study was to examine the validity and reliability of the YMCA submaximal exercise test protocol performed on a newly-designed rectilinear stepping ergometer (RSE) that used up and down reciprocating vertical motion in place of conventional circular motion and giving precise measurement of workload, to determine V̇O 2 max in young healthy male adults. Thirty-two young healthy male adults (32 males; age range: 20-35 years; height: 1.75 ± 0.05 m; weight: 67.5 ± 8.6 kg) firstly participated in a maximal-effort graded exercise test using a cycle ergometer (CE) to directly obtain measured V̇O 2 max. Subjects then completed the progressive multistage test on the RSE beginning at 50W and including additional stages of 70, 90, 110, 130, and 150W, and the RSE YMCA submaximal test consisting of a workload increase every 3 minutes until the termination criterion was reached. A metabolic equation was derived from the RSE multistage exercise test to predict oxygen consumption (V̇O 2 ) from power output (W) during the submaximal exercise test (V̇O 2 (mL·min -1 )=12.4 ×W(watts)+3.5 mL·kg -1 ·min -1 ×M+160mL·min -1 , R 2 = 0.91, standard error of the estimate (SEE) = 134.8mL·min -1 ). A high correlation was observed between the RSE YMCA estimated V̇O 2 max and the CE measured V̇O 2 max (r=0.87). The mean difference between estimated and measured V̇O 2 max was 2.5 mL·kg -1 ·min -1 , with an SEE of 3.55 mL·kg -1 ·min -1 . The data suggest that the RSE YMCA submaximal exercise test is valid for predicting V̇O 2 max in young healthy male adults. The findings show that the rectilinear stepping exercise is an effective submaximal exercise for predicting V̇O 2 max. The newly-designed RSE may be potentially further developed as an alternative ergometer for assessing

Characterisation of baroreflex sensitivity of recreational ultra-endurance athletes.

Science.gov (United States)

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

2014-01-01

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

Business Process Reengineering within the bicycle industry

OpenAIRE

Bartolomé Rodriguez, David

2010-01-01

Bicycle leader brands have shift production overseas to reduce the cost of labor and to implement new technologies at lower cost. Bike manufacturer both in Asia and Europe employ a traditional way of production  based on economics of scale that aims cost per unit reduction. Where MRP systems and forecasting are part of their day basis operations. This traditional way of operation offers room for innovation that must be seen as a business opportunity. Thus, alternative management approaches ca...

Action of bicyclic isoxazole GABA analogues on GABA transporters and its relation to anticonvulsant activity

DEFF Research Database (Denmark)

Bolvig, T; Larsson, O M; Pickering, D S

1999-01-01

The inhibitory action of bicyclic isoxazole gamma-aminobutyric acid (GABA) analogues and their 4,4-diphenyl-3-butenyl (DPB) substituted derivatives has been investigated in cortical neurones and astrocytes as well as in human embryonic kidney (HEK 293) cells transiently expressing either mouse GA...... anticonvulsant activity, lack of proconvulsant activity and the ability of THPO to increase extracellular GABA concentration, indicate that these bicyclic isoxazole GABA analogues and their DPB derivatives may be useful lead structures in future search for new antiepileptic drugs....

The effects of operating a touch screen smartphone and other common activities performed while bicycling on cycling behaviour

NARCIS (Netherlands)

de Waard, Dick; Lewis Evans, Ben; Jelijs, Bart; Tucha, Oliver; Brookhuis, Karel

Although it has been shown that making phone calls or sending text messages while riding a bicycle can have a negative impact on bicyclist’s behaviour, in countries such as the Netherlands the operation of a mobile phone while cycling on a bicycle is not illegal and is actually quite common. In

Intra-individual psychological and physiological responses to acute laboratory stressors of different intensity.

Science.gov (United States)

Skoluda, Nadine; Strahler, Jana; Schlotz, Wolff; Niederberger, Larissa; Marques, Sofia; Fischer, Susanne; Thoma, Myriam V; Spoerri, Corinne; Ehlert, Ulrike; Nater, Urs M

2015-01-01

The phenomenon of stress is understood as a multidimensional concept which can be captured by psychological and physiological measures. There are various laboratory stress protocols which enable stress to be investigated under controlled conditions. However, little is known about whether these protocols differ with regard to the induced psycho-physiological stress response pattern. In a within-subjects design, 20 healthy young men underwent four of the most common stress protocols (Stroop test [Stroop], cold pressor test [CPT], Trier Social Stress Test [TSST], and bicycle ergometer test [Ergometer]) and a no-stress control condition (rest) in a randomized order. For the multidimensional assessment of the stress response, perceived stress, endocrine and autonomic biomarkers (salivary cortisol, salivary alpha-amylase, and heart rate) were obtained during the experiments. All stress protocols evoked increases in perceived stress levels, with the highest levels in the TSST, followed by Ergometer, Stroop, and CPT. The highest HPA axis response was found in the TSST, followed by Ergometer, CPT, and Stroop, whilst the highest autonomic response was found in the Ergometer, followed by TSST, Stroop, and CPT. These findings suggest that different stress protocols differentially stimulate various aspects of the stress response. Physically demanding stress protocols such as the Ergometer test appear to be particularly suitable for evoking autonomic stress responses, whereas uncontrollable and social-evaluative threatening stressors (such as the TSST) are most likely to elicit HPA axis stress responses. The results of this study may help researchers in deciding which stress protocol to use, depending on the individual research question. Copyright © 2014 Elsevier Ltd. All rights reserved.

Generation of Polar Semi-Saturated Bicyclic Pyrazoles for Fragment-Based Drug Discovery Campaigns.

Science.gov (United States)

Luise, Nicola; Wyatt, Paul

2018-05-07

Synthesising polar semi-saturated bicyclic heterocycles can lead to better starting points for fragment-based drug discovery (FBDD) programs. This communication highlights the application of diverse chemistry to construct bicyclic systems from a common intermediate, where pyrazole, a privileged heteroaromatic able to bind effectively to biological targets, is fused to diverse saturated counterparts. The generated fragments can be further developed either after confirmation of their binding pose or early in the process, as their synthetic intermediates. Essential quality control (QC) for selection of small molecules to add to a fragment library is discussed. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Driver braking behavior analysis to improve autonomous emergency braking systems in typical Chinese vehicle-bicycle conflicts.

Science.gov (United States)

Duan, Jingliang; Li, Renjie; Hou, Lian; Wang, Wenjun; Li, Guofa; Li, Shengbo Eben; Cheng, Bo; Gao, Hongbo

2017-11-01

Bicycling is one of the fundamental modes of transportation especially in developing countries. Because of the lack of effective protection for bicyclists, vehicle-bicycle (V-B) accident has become a primary contributor to traffic fatalities. Although AEB (Autonomous Emergency Braking) systems have been developed to avoid or mitigate collisions, they need to be further adapted in various conflict situations. This paper analyzes the driver's braking behavior in typical V-B conflicts of China to improve the performance of Bicyclist-AEB systems. Naturalistic driving data were collected, from which the top three scenarios of V-B accidents in China were extracted, including SCR (a bicycle crossing the road from right while a car is driving straight), SCL (a bicycle crossing the road from left while a car is driving straight) and SSR (a bicycle swerving in front of the car from right while a car is driving straight). For safety and data reliability, a driving simulator was employed to reconstruct these three scenarios and some 25 licensed drivers were recruited for braking behavior analysis. Results revealed that driver's braking behavior was significantly influenced by V-B conflict types. Pre-decelerating behaviors were found in SCL and SSR conflicts, whereas in SCR the subjects were less vigilant. The brake reaction time and brake severity in lateral V-B conflicts (SCR and SCL) was shorter and higher than that in longitudinal conflicts (SSR). The findings improve their applications in the Bicyclist-AEB and test protocol enactment to enhance the performance of Bicyclist-AEB systems in mixed traffic situations especially for developing countries. Copyright © 2017 Elsevier Ltd. All rights reserved.

Walking, bicycling, and sports in postmenopausal breast cancer survivors--results from a German patient cohort study.

Science.gov (United States)

Bock, Christina; Schmidt, Martina E; Vrieling, Alina; Chang-Claude, Jenny; Steindorf, Karen

2013-06-01

Physical activity (PA) is increasingly discussed as a means to achieve both physical and psychological benefits for breast cancer patients and survivors. However, little is known about activity-specific PA behavior following diagnosis. Our objectives were to describe sports and active transportation in the course of breast cancer and to identify factors associated with these activities. We used data from a German cohort study including 1067 postmenopausal breast cancer survivors aged 50-75 years. Data were collected about walking and bicycling for transportation purposes and sports before diagnosis, during therapy, and 1 year after surgery. Associations between these activities and clinical, behavioral, and social characteristics were analyzed with logistic regression. The proportions of physically active women decreased significantly during therapy compared with before diagnosis (walking: 75.1% vs. 89.7%; bicycling: 19.3% vs. 56.5%; sports: 14.8% vs. 64.5%; all p sport. Chemotherapy/radiotherapy was negatively associated with sports (odds ratio [OR]: 0.35 [0.17-0.73]) but positively associated with walking during therapy (OR: 2.08 [1.04-4.15]). Although sociodemographic factors showed weak associations with PA, participation in rehabilitation increased the likelihood for bicycling (OR: 1.48 [1.06-2.09]) and sports (OR: 1.88 [1.38-2.58]) 1 year after surgery. The majority of women stopped exercising and bicycling during breast cancer therapy. Interventions promoting in particular moderate activities after breast cancer diagnosis are required for this population. Increasing participation in rehabilitation might help to increase the proportion of women who bicycle and engage in sports after breast cancer diagnosis. Copyright © 2012 John Wiley & Sons, Ltd.

Nonfatal bicycle accident risk after an evening of alcohol consumption

NARCIS (Netherlands)

Verster, J.C.; van Herwijnen, J.; Volkerts, E.R.; Olivier, B.

2009-01-01

Introduction: After an evening of alcohol consumption, blood alcohol concentration (BAC) may reach intoxication levels above legal limits for operating a car or bicycle. In the Netherlands, legal limits for participating in traffic are 0.05% for experienced drivers and 0.02% for novice drivers. The

Life-long endurance exercise in humans

DEFF Research Database (Denmark)

Mikkelsen, U R; Couppé, C; Karlsen, A

2013-01-01

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

Association between neighborhood walkability and GPS-measured walking, bicycling and vehicle time in adolescents.

Science.gov (United States)

Carlson, Jordan A; Saelens, Brian E; Kerr, Jacqueline; Schipperijn, Jasper; Conway, Terry L; Frank, Lawrence D; Chapman, Jim E; Glanz, Karen; Cain, Kelli L; Sallis, James F

2015-03-01

To investigate relations of walking, bicycling and vehicle time to neighborhood walkability and total physical activity in youth. Participants (N=690) were from 380 census block groups of high/low walkability and income in two US regions. Home neighborhood residential density, intersection density, retail density, entertainment density and walkability were derived using GIS. Minutes/day of walking, bicycling and vehicle time were derived from processing algorithms applied to GPS. Accelerometers estimated total daily moderate-to-vigorous physical activity (MVPA). Models were adjusted for nesting of days (N=2987) within participants within block groups. Walking occurred on 33%, active travel on 43%, and vehicle time on 91% of the days observed. Intersection density and neighborhood walkability were positively related to walking and bicycling and negatively related to vehicle time. Residential density was positively related to walking. Increasing walking in youth could be effective in increasing total physical activity. Built environment findings suggest potential for increasing walking in youth through improving neighborhood walkability. Copyright © 2014 Elsevier Ltd. All rights reserved.

[Abortion using a bicycle pump on the mistress and unusual suicide of a blind man].

Science.gov (United States)

Holzer, F J

1973-01-01

In Tyrol a case of fatal air embolism after an abortion attempt with a bicycle pump, performed by a blind man who later committed suicide, is described. The bicycle tube was inserted into the vagina and air and a soapy solution were pumped in. Autopsies revealed internal bleeding, gas embolisms in the veins of the ovaries and heart, a bloody foamy liquid in the lungs, and an intact 14 cm male fetus. 3 similar cases of fatal air embolisms after abortion attempts with bicycle pumps are described. In 1 case a soapy solution had been injected. Abortion attempts with a pipe and a rubber catheter, reported here, also resulted in rapidly fatal air embolisms. In 1 case death occurred a few seconds after a partner blew air with his mouth into his pregnant mistress' vagina. It is concluded that under some conditions filling the vagina with air (tightly) can cause fatal air embolisms.

Oxygen uptake in water polo, comparison and agreement in cycle ergometer and eggbeater kick: A pilot study

Directory of Open Access Journals (Sweden)

Ligia Ignêz Engelmann

Full Text Available Abstract The aim of this study was to compare and verify the agreement of maximal oxygen uptake (VO2 max values obtained from tests on land and in water. Twelve recreational water polo players (30.5 ± 7.7 years; 79.2 ± 7.2 kg body mass; 179.1 ± 5.9 cm height were assessed in two phases: (1 in laboratory with maximal test on a cycle ergometer and (2 in a swimming pool with maximal test in eggbeater kick. Maximum values obtained in the two tests (respectively, cycle ergometer, and eggbeater kick: VO2 max = 40.2 ± 2.7 ml.kg-1.min-1 and 38.4 ± 5.7 ml.kg-1.min-1; RER = 1.17 ± 0.08 and 1.19 ± 0.12; HR max = 181.4 ± 11.7 bpm and 179 ± 11.7 bpm; IEP = 20 and 20 did not show significant differences. According to the Bland-Altman analyses, there were acceptable limits of agreement between the two tests (land and water. Therefore, it can be concluded that the eggbeater kick test is a specific and valid protocol to asses VO2 max in water polo players.

Improving Energy Efficiency of an Autonomous Bicycle with Adaptive Controller Design

Directory of Open Access Journals (Sweden)

David Rodriguez-Rosa

2017-05-01

Full Text Available A method is proposed to achieve lateral stability of an autonomous bicycle with only the rotation of the front wheel. This can be achieved with a classic controller. However, if the energy consumption of the bicycle also has to be minimized, this solution is not valid. To solve this problem, an adaptive controller has been designed, which modifies its gains according to the bicycle’s forward velocity, adapting its response with minimum energy consumption and satisfying the design specifications. The study demonstrates the efficiency of the proposed control, achieving an energy saving of 73 . 8 % in trajectory tracking with respect to a conventional proportional-integral ( P I controller. These results show the importance of designing energy-efficient controllers, not only for autonomous vehicles but also for any automatic system where the energy consumption can be minimized.

Uzobo, Endurance

African Journals Online (AJOL)

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

Associations Between Bicycling and Fall Related Physical Performance in Older Adults

NARCIS (Netherlands)

Pijnappels, M.A.G.M.

2017-01-01

Falls among older adults remains a significant public health issue. Bicycling positively influences falls risk factors including reduced balance, muscle weakness, and low self-perceived confidence in maintaining balance. However, this association has not been systematically examined. We recruited

Will a bicycle friendly policy make passenger travel more sustainably?

DEFF Research Database (Denmark)

Christensen, Linda; Jensen, Thomas Christian

and bicycling. The study shows that instruments that improve the cyclists’ speed and increase the car drivers’ time consumption and costs will influence the competition conditions significantly. The total transfer potential will be between 12 and 16 % of the car trips in case of short tours, equivalent to 1...

Study of speed endurance middle distance runners

Directory of Open Access Journals (Sweden)

R.V. Golovaschenko

2013-12-01

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

Veterinary problems of endurance horses in England and Wales.

Science.gov (United States)

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

2017-05-01

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

'Cycle thieves, we are watching you': impact of a simple signage intervention against bicycle theft.

Science.gov (United States)

Nettle, Daniel; Nott, Kenneth; Bateson, Melissa

2012-01-01

Bicycle theft is a serious problem in many countries, and there is a lack of evidence concerning effective prevention strategies. Displaying images of 'watching eyes' has been shown to make people behave in more socially desirable ways in a number of settings, but it is not yet clear if this effect can be exploited for purposes of crime prevention. We report the results of a simple intervention on a university campus where signs featuring watching eyes and a related verbal message were displayed above bicycle racks. We installed durable signs at three locations which had experienced high levels of bicycle theft, and used the rest of the university campus as a control location. Reported thefts were monitored for 12 months before and after the intervention. Bicycle thefts decreased by 62% at the experimental locations, but increased by 65% in the control locations, suggesting that the signs were effective, but displaced offending to locations with no signs. The Odds Ratio for the effect of the intervention was 4.28 (95% confidence interval 2.04-8.98), a large effect compared to other place-based crime prevention interventions. The effectiveness of this extremely cheap and simple intervention suggests that there can be considerable crime-reduction benefits to engaging the psychology of surveillance, even in the absence of surveillance itself. Simple interventions for high-crime locations based on this principle should be considered as an adjunct to other measures, although a possible negative consequence is displacement of offending.

Effect of caffeine intake on critical power model parameters determined on a cycle ergometer

Directory of Open Access Journals (Sweden)

Marcus Vinicius Machado

2010-01-01

Full Text Available The aim of this study was to evaluate the effect of caffeine intake on critical power model parameters determined on a cycle ergometer. Eight male subjects participated in this study. A double-blind protocol consisting of the intake of pure caffeine (6 mg/kg or placebo (maltodextrin 60 min before testing was used. Subjects were submitted to four constant-load tests on a cycle ergometer. These tests were conducted randomly in the caffeine and placebo groups [checar] at intensities of 80, 90, 100 and 110% maximum power at a rate of 70 rpm until exhaustion to determine the critical power. As a criterion for stopping the test was adopted any rate fall without recovery by more than five seconds. The critical power and anaerobic work capacity were obtained by nonlinear regression and fitting of the curve to a hyperbolic power-time model. The Shapiro-Wilk test and paired Student t-test were used for statistical analysis. No significant differences in critical power were observed between the caffeine and placebo groups (192.9 ± 31.3 vs 197.7 ± 29.4 W, respectively. The anaerobic work capacity was significantly higher in the caffeine group (20.1 ± 5.2 vs 16.3 ± 4.2 W, p< 0.01. A high association (r2 was observed between the caffeine and placebo conditions (0.98 ± 0.02 and 0.99 ± 0.0, respectively. We conclude that caffeine intake did not improve critical power performance but increased anaerobic work capacity by influencing performance at loads of higher intensity and shorter duration.

Injury rates from walking, gardening, weightlifting, outdoor bicycling, and aerobics.

Science.gov (United States)

Powell, K E; Heath, G W; Kresnow, M J; Sacks, J J; Branche, C M

1998-08-01

The objective of this survey was to estimate the frequency of injuries associated with five commonly performed moderately intense activities: walking for exercise, gardening and yard work, weightlifting, aerobic dance, and outdoor bicycling. National estimates were derived from weighted responses of over 5,000 individuals contacted between April 28 and September 18, 1994, via random-digit dialing of U.S. residential telephone numbers. Self-reported participation in these five activities in the late spring and summer of 1994 was common, ranging from an estimated 14.5 +/- 1.2% of the population for aerobics (nearly 30 million people) to 73.0 +/- 1.5% for walking (about 138 million people). Among participants, the activity-specific 30-d prevalence of injury ranged from 0.9 +- 0.5% for outdoor bicycle riding to 2.4 +- 1.3% for weightlifting. The estimated number in the 30 d of people injured in the 30 d before their interview ranged from 330,000 for outdoor bicycle riding to 2.1 million for gardening or yard work. Incidence rates for injury causing reduced participation in activity were 1.1 +/- 0.5x100 participantsx30 d for walking, 1.1 +/- 0.4 for gardening, and 3.3 +/- 1.9 for weightlifting. During walking and gardening, men and women were equally likely to be injured, but younger people (18-44 yr) were more likely to be injured than older people (45 + yr). Injury rates were low, yet large numbers of people were injured because participation rates were high. Most injuries were minor, but injuries may reduce participation in these otherwise beneficial activities. Additional studies to confirm the magnitude of the problem, to identify modifiable risk factors, and to recommend methods to reduce the frequency of such injuries are needed.

An experiment on rider stability while mounting: Comparing middle-aged and elderly cyclists on pedelecs and conventional bicycles.

Science.gov (United States)

Twisk, D A M; Platteel, S; Lovegrove, G R

2017-08-01

Pedelecs, popular among elderly cyclists, are associated with a higher injury risk than conventional bicycles. About 17% of these injuries are due to falls while (dis)mounting. Using instrumented bicycles, this study aimed to identify factors contributing to the stability of self-chosen mounting methods in four user groups: 30-45 versus 65+ years of age and males versus females. Mounting stability on pedelecs was compared with that on conventional bicycles, in controlled experimental setting (task in a fenced off parking lot) but also in real traffic conditions (traffic light turns green). Two mounting phases were differentiated: phase 1 as the transition from 'earth bound' to 'balance' and phase 2 as the acceleration to achieve harmonized cycling. Stability was operationalised in terms of the duration of these phases: the shorter their duration, the higher the stability. Pedelecs were shown to be less stable in phase 1 than conventional bicycles, irrespective of user group. For all user groups, only in phase 2 the advantages of electrical support kicked in. Results obtained in traffic conditions confirmed the patterns obtained in the controlled setting, with as only difference a lower speed in traffic conditions, which held for both mounting phases and bicycle types. Also measures of physical limitations due to low muscle strength were shown only to be compensated for by pedal support in phase 2 and not in phase 1. Further, mounting characteristics affected pedelec stability in phase 1 and not in phase 2. Higher stability was associated with a) starting while seated and b) using the pedal to push off. Although, these mounting characteristics were confounded with age, gender, and muscle strength, the pattern of results still suggest certain mounting techniques to be more beneficial for pedelecs. The results further illustrate the importance of a deeper understanding of the interactions of bicycle types and user groups on critical manoeuvres and their potential

'Cycle thieves, we are watching you': impact of a simple signage intervention against bicycle theft.

Directory of Open Access Journals (Sweden)

Daniel Nettle

Full Text Available Bicycle theft is a serious problem in many countries, and there is a lack of evidence concerning effective prevention strategies. Displaying images of 'watching eyes' has been shown to make people behave in more socially desirable ways in a number of settings, but it is not yet clear if this effect can be exploited for purposes of crime prevention. We report the results of a simple intervention on a university campus where signs featuring watching eyes and a related verbal message were displayed above bicycle racks.We installed durable signs at three locations which had experienced high levels of bicycle theft, and used the rest of the university campus as a control location. Reported thefts were monitored for 12 months before and after the intervention. Bicycle thefts decreased by 62% at the experimental locations, but increased by 65% in the control locations, suggesting that the signs were effective, but displaced offending to locations with no signs. The Odds Ratio for the effect of the intervention was 4.28 (95% confidence interval 2.04-8.98, a large effect compared to other place-based crime prevention interventions.The effectiveness of this extremely cheap and simple intervention suggests that there can be considerable crime-reduction benefits to engaging the psychology of surveillance, even in the absence of surveillance itself. Simple interventions for high-crime locations based on this principle should be considered as an adjunct to other measures, although a possible negative consequence is displacement of offending.

The Synthesis of cis- and trans-Fused Bicyclic Sugar Amino Acids

NARCIS (Netherlands)

Risseeuw, Martijn D.P.; Grotenbreg, Gijsbert M.; Witte, Martin D.; Tuin, Adriaan W.; Leeuwenburgh, Michiel A.; Marel, Gijsbert A. van der; Overkleeft, Herman S.; Overhand, Mark

2006-01-01

Four isomeric bicyclic sugar amino acids (SAAs) were prepared from an α-acetylenic-C-glucoside by employing a Petasis olefination and a ring-closing metathesis (RCM) as key steps. The applicability of the resulting SAAs in solid-phase peptide synthesis was demonstrated by the synthesis of a

A Novel Electric Bicycle Battery Monitoring System Based on Android Client

Directory of Open Access Journals (Sweden)

Chuanxue Song

2017-01-01

Full Text Available The battery monitoring system (BMS plays a crucial role in maintaining the safe operation of the lithium battery electric bicycle and prolonging the life of the battery pack. This paper designed a set of new battery monitoring systems based on the Android system and ARM single-chip microcomputer to enable direct management of the lithium battery pack and convenient monitoring of the state of the battery pack. The BMS realizes the goal of monitoring the voltage, current, and ambient temperature of lithium batteries, estimating the state of charge (SOC and state of health (SOH, protecting the battery from abuse during charging or discharging, and ensuring the consistency of the batteries by integrating the passive equalization circuit. The BMS was proven effective and feasible through several tests, including charging/discharging, estimation accuracy, and communication tests. The results indicated that the BMS could be used in the design and application of the electric bicycle.

Integration of bicycling and walking facilities into the infrastructure of urban communities.

Science.gov (United States)

2012-02-01

Several manuals, handbooks and web resources exist to provide varied guidance on planning for and designing bicycle and pedestrian facilities, yet there are no specific indications about which of the varied treatments in these guides work well for us...

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

Science.gov (United States)

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

2016-05-01

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

From on-road trial evaluation of electric and conventional bicycles to comparison with other urban transport modes: Case study in the city of Lisbon, Portugal

International Nuclear Information System (INIS)

Baptista, Patrícia; Pina, André; Duarte, Gonçalo; Rolim, Catarina; Pereira, Gonçalo; Silva, Carlos; Farias, Tiago

2015-01-01

Highlights: • Five transportation alternatives were compared in Lisbon, Portugal. • Electric bicycles allowed increasing average speed from 8% to 26%, mainly in positive slopes. • WTW energy consumption of electric bicycle was 1–11% of the other transport options impacts. • Alternatives’ low energy needs and zero local emissions contributes to improve urban air quality. - Abstract: Increasing energy costs, energy consumption and emissions profiles prompted the promotion of different transportation alternatives. This research work addresses the comparison of trip dynamics, energy consumption, CO 2 and NO x Well-to-Wheel impacts of 5 transportation alternatives (conventional and electric bicycles, conventional and electric vehicles and an urban bus) in Lisbon, Portugal. On-road monitoring of a specific route in Lisbon revealed that bikers using electric bicycles increased their average speed between 8% and 26% compared to their use of the conventional bicycle, especially in the route sections with positive slopes (up to 49% increases). Electric bicycles result in a Tank-to-Wheel energy consumption of 0.028 MJ/km, allowing an average autonomy of 46 km between recharging. When comparing the 5 transportation alternatives, the electric bicycles presented a higher travel time of 13.5%, 1.9% and 7.8% over the bus, low powered electric vehicle, and standard electric vehicle/conventional technologies, respectively. Regarding the Well-to-Wheel energy consumption analysis, the results indicated that, when compared to the other transportation solutions, the electric bicycle only uses 11%, 3%, 1%, 2% and 4% of the energy required when using the low powered electric vehicle, standard electric vehicle, conventional gasoline and diesel technologies and bus, respectively. Furthermore, the analysis of Well-to-Wheel emissions reveals that the electric bicycle has 13% and 4% lower CO 2 emissions and 12% and 4% lower NO x emissions when compared to the low powered and

High-intensity lower limb endurance training in chronic respiratory disease

OpenAIRE

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

2015-01-01

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

[Medical coverage of a road bicycle race].

Science.gov (United States)

Reifferscheid, Florian; Stuhr, Markus; Harding, Ulf; Schüler, Christine; Thoms, Jürgen; Püschel, Klaus; Kappus, Stefan

2010-07-01

Major sport events require adequate expertise and experience concerning medical coverage and support. Medical and ambulance services need to cover both participants and spectators. Likewise, residents at the venue need to be provided for. Concepts have to include the possibility of major incidents related to the event. Using the example of the Hamburg Cyclassics, a road bicycle race and major event for professional and amateur cyclists, this article describes the medical coverage, number of patients, types of injuries and emergencies. Objectives regarding the planning of future events and essential medical coverage are consequently discussed. (c) Georg Thieme Verlag Stuttgart-New York.

Jump ergometer in sport performance testing Výskokový ergometr v diagnostice sportovní výkonnosti

Directory of Open Access Journals (Sweden)

Dušan Hamar

2005-02-01

Full Text Available The papers deals with the application of the jump ergometer in the evaluation of neuromuscular performance. Altogether 288 athletes of different sport specializations (mean age 18.9 ± 6.4 years, height 172.2 ± 4.3 cm, and weight 62.4 ± 4.9 kg underwent various tests on the jump ergometer, such as 10-, 60-, and 90-second repeated jumps, squat and countermovement jumps without and with an additional load, and drop jumps from different heights with and without bending the knees. The diagnostic system FiTRO Jumper consisting of a special contact switch mattress connected by means of an interface to a computer was used. Jump parameters (power in the active phase of take off and height of the jump were calculated from the flight and contact times. Results showed that the system may be applied for the assessment of explosive power of the lower extremities, strength endurance of the lower extremities, utilization of the stretch shortening cycle, distribution of fast twitch fibers, optimal drop jump height for plyometric training, and training effects, namely in sports such as basketball, volleyball, soccer, tennis, gymnastics, rock and roll, figure skating, track and field, ski jumping, weight lifting, etc. Práce poukazuje na možnosti uplatnění výskokového ergometru při posuzovaní odrazových schopností dolních končetin. Celkem 288 sportovců s různou specializací (průměrný věk 18,9 ± 6,4 let, výška 172,2 ± 4,3 cm, hmotnost 62,4 ± 4,9 kg absolvovalo testy na výskokovém ergometru, a to 10, 60 a 90sekundový test opakovaných snožných výskoků, výskoky bez a s protipohybem s hmotností vlastního těla, resp. s dodatečnou váhou, jakož i seskoky z různych výšek do rovných, resp. pokrčených dolních končetin. Parametry odrazových schopností (výkon v aktivní fázi odrazu a výška výskoku byly registrovány pomocí diagnostického systému FiTRO Jumper sestávajícího z odrazové doby napojené prost

A Bayesian Network Model on the Public Bicycle Choice Behavior of Residents: A Case Study of Xi’an

Directory of Open Access Journals (Sweden)

Qiuping Wang

2017-01-01

Full Text Available In order to study the main factors affecting the behaviors that city residents make regarding public bicycle choice and to further study the public bicycle user’s personal characteristics and travel characteristics, a travel mode choice model based on a Bayesian network was established. Taking residents of Xi’an as the research object, a K2 algorithm combined with mutual information and expert knowledge was proposed for Bayesian network structure learning. The Bayesian estimation method was used to estimate the parameters of the network, and a Bayesian network model was established to reflect the interactions among the public bicycle choice behaviors along with other major factors. The K-fold cross-validation method was used to validate the model performance, and the hit rate of each travel mode was more than 80%, indicating the precision of the proposed model. Experimental results also present the higher classification accuracy of the proposed model. Therefore, it may be concluded that the resident travel mode choice may be accurately predicted according to the Bayesian network model proposed in our study. Additionally, this model may be employed to analyze and discuss changes in the resident public bicycle choice and to note that they may possibly be influenced by different travelers’ characteristics and trip characteristics.

Compliance to Standard Equipment Requirements by Exercise Therapy/Fitness Outfits in The South-South Geopolitical Zone of Nigeria

Directory of Open Access Journals (Sweden)

Oluwaseun S. Kubeyinje

2016-08-01

Full Text Available The purpose of this study was to assess the compliance of exercise therapy/fitness outfits in the south-south geopolitical zone of Nigeria to standard equipment requirements. Descriptive survey design was adopted for the conduct of the study using a sample size of 51centres/managers purposively selected from a population of 102 managers of fitness outfits in the six states of the south-south geopolitical zone of Nigeria. A self- developed structured questionnaire and a facility checklist were used to collect the data. Data collected were analysed using frequency counts and percentages. The study revealed in this analysis that only treadmills (66.7%, bicycle ergometers (66.7%, dumbbells (84.3% and weight racks (57.0% met the benchmark minimum in more than 50% of the exercise therapy/fitness outfits surveyed in six states of the south-south geopolitical zone of Nigeria. Most of the equipment surveyed were functional with the highest non-functionality occurring in treadmill machines in 9.8% of the surveyed centres followed by sit-up benches (5.9% and bicycle ergometers (3.9%. In conclusion, it could be deduced from the results that there’s gross inadequacy of equipment and low level of compliance to established standard in the exercise therapy/fitness outfits evaluated in the south-south geopolitical zone of Nigeria.

2002 bicycle transportation user survey ; developing intermodal connections for the 21st century

Science.gov (United States)

2004-12-01

The Rhode Island Department of Transportation (RIDOT) has been on the forefront in recognizing the potential for bicycle travel to provide mobility, reduce congestion, improve environmental quality, and promote healthy lifestyles. An important compon...

The effect of cannabis on regular cannabis consumers' ability to ride a bicycle.

Science.gov (United States)

Hartung, Benno; Schwender, Holger; Roth, Eckhard H; Hellen, Florence; Mindiashvili, Nona; Rickert, Annette; Ritz-Timme, Stefanie; Grieser, Almut; Monticelli, Fabio; Daldrup, Thomas

2016-05-01

To assess the effects of cannabis on the ability required to ride a bicycle, repetitive practical cycling tests and medical examinations were carried out before and after inhalative consumption of cannabis. A maximum of three joints with body weight-adapted THC content (300 μg THC per kg body weight) could be consumed by each test subject. Fourteen regular cannabis-consuming test subjects were studied (12 males, 2 females). In summary, only a few driving faults were observed even under the influence of very high THC concentrations. A defined THC concentration that leads to an inability to ride a bicycle cannot be presented. The test subjects showed only slight distinctive features that can be documented using a medical test routinely run for persons under suspicion of driving under the influence of alcohol or drugs.

Aminocyclopentanols as sugar mimics. Synthesis from unsaturated bicyclic lactones by Overman rearrangement

DEFF Research Database (Denmark)

Bøjstrup, Marie; Fanefjord, Mette; Lundt, Inge

2007-01-01

Bicyclic cyclopentane lactones, prepared from bromodeoxyaldonolactones, were transformed into aminocyclopentanols with an Overman rearrangement as the key step. Two of the compounds prepared, 7 and 19, were found to be good inhibitors of jack bean alpha-mannosidase and beta-D-N-acetylglucosaminid...

A field-based approach for examining bicycle seat design effects on seat pressure and perceived stability.

Science.gov (United States)

Bressel, Eadric; Bliss, Shantelle; Cronin, John

2009-05-01

The purpose of this study was to investigate the effect of various bicycle seat designs on seat pressure and perceived stability in male and female cyclists using a unique field-based methodology. Thirty participants, comprising male and female cyclists, pedaled a bicycle at 118W over a 350m flat course under three different seat conditions: standard seat, a seat with a partial anterior cutout, and a seat with a complete anterior cutout. The pressure between the bicycle seat and perineum of the cyclist was collected with a remote pressure-sensing mat, and perceived stability was assessed using a continuous visual analogue scale. Anterior seat pressure and stability values for the complete cutout seat were significantly lower (p<0.05; 62-101%) than values for the standard and partial cutout designs. These findings were consistent between males and females. Our results would support the contention that the choice of saddle design should not be dictated by interface pressure alone since optimal anterior seat pressure and perceived seat stability appear to be inversely related.

Tertiary Student Attitudes to Bicycle Commuting in a Regional Australian University

Science.gov (United States)

Whannell, Patricia; Whannell, Robert; White, Richard

2012-01-01

Purpose: The purpose of this paper is to provide executive management at a regional university with empirical data to justify, or otherwise, a substantial outlay of funds to support bicycle commuting as a viable strategy for the reduction of traffic congestion. Design/methodology/approach: A custom designed questionnaire was completed by 270…

Workshop to review problem-behavior research programs : pedestrian, bicycle, and pupil transportation safety

Science.gov (United States)

1981-09-01

This report presents the proceedings of a workshop on pedestrian, bicycle, and pupil transportation safety. The purpose of this workshop was to develop specific recommendations for the planning and implementation of NHTSA research, development, and d...

Exercise capacity in non-specific chronic low back pain patients : A lean body mass-based Astrand bicycle test; Reliability, validity and feasibility

NARCIS (Netherlands)

Hodselmans, Audy P.; Dijkstra, Pieter U.; Geertzen, Jan H. B.; van der Schans, Cees P.

Objective Measurement of exercise capacity is essential in patients with non-specific chronic low back pain (CLBP). However, the conventional Astrand bicycle test is not feasible in patients with a very poor aerobic capacity. Therefore the Astrand bicycles test for non-specific CLBP patients based

Nutritional habits among high-performance endurance athletes

Directory of Open Access Journals (Sweden)

Marius Baranauskas

2015-01-01

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

‘Cycle Thieves, We Are Watching You’: Impact of a Simple Signage Intervention against Bicycle Theft

Science.gov (United States)

Nettle, Daniel; Nott, Kenneth; Bateson, Melissa

2012-01-01

Background Bicycle theft is a serious problem in many countries, and there is a lack of evidence concerning effective prevention strategies. Displaying images of ‘watching eyes’ has been shown to make people behave in more socially desirable ways in a number of settings, but it is not yet clear if this effect can be exploited for purposes of crime prevention. We report the results of a simple intervention on a university campus where signs featuring watching eyes and a related verbal message were displayed above bicycle racks. Methodology and Principal Findings We installed durable signs at three locations which had experienced high levels of bicycle theft, and used the rest of the university campus as a control location. Reported thefts were monitored for 12 months before and after the intervention. Bicycle thefts decreased by 62% at the experimental locations, but increased by 65% in the control locations, suggesting that the signs were effective, but displaced offending to locations with no signs. The Odds Ratio for the effect of the intervention was 4.28 (95% confidence interval 2.04–8.98), a large effect compared to other place-based crime prevention interventions. Conclusions and Significance The effectiveness of this extremely cheap and simple intervention suggests that there can be considerable crime-reduction benefits to engaging the psychology of surveillance, even in the absence of surveillance itself. Simple interventions for high-crime locations based on this principle should be considered as an adjunct to other measures, although a possible negative consequence is displacement of offending. PMID:23251615

Supra maximal bicycle tests do not detect seasonable progress in groups of elite speed skaters

NARCIS (Netherlands)

van Ingen Schenau, G.J.; Bakker, F.C.; de Groot, G.; de Koning, J.J.

1992-01-01

Seven female and eight male elite junior skaters performed cycle ergometer tests at four different times during the 1987/1988 season. The tests consisted of a Wingate-type 30-s sprint test and a 2.5-min supramaximal test. The subjects were tested in February, May and September 1987 and in January

Bicycle physics and biomechanics. Techniques - formulas - laws. 9. rev. and enl. ed.; Fahrradphysik und Biomechanik. Technik - Formeln - Gesetze

Energy Technology Data Exchange (ETDEWEB)

Gressmann, M.

2005-07-01

Michael Gressmann explains the physical aspects of bicycle riding by numerous concrete examples: Acceleration and velocity, friction and rolling resistance, steering-gear angle and displacement, under- and override, bicycle gear/chain gear, muscle activity in the pedaling, energy and power balance. From this follow many interesting hints for the riding technique and the selection of the technical material. Especially valuable for the practitioner: Considerations and calculations on aerial resistance, gyro forces, frame geometry, seat position, and pedaling frequency.

Production of liquid fuels and chemicals from pyrolysis of Bangladeshi bicycle/rickshaw tire wastes

Energy Technology Data Exchange (ETDEWEB)

Islam, M. Rofiqul; Tushar, M.S.H.K. [Department of Mechanical Engineering, Rajshahi University of Engineering and Technology, Rajshahi 6204 (Bangladesh); Haniu, H. [Department of Mechanical Engineering, Kitami Institute of Technology, Kitami City, Hokkaido 090-8507 (Japan)

2008-05-15

Tire wastes in the form of used bicycle/rickshaw tires available in Bangladesh were pyrolyzed in a fixed-bed fire-tube heating reactor under different pyrolysis conditions to determine the role of final temperature, sweeping gas flow rate and feed size on the product yields and liquid product composition. Final temperature range studied was between 375 and 575 C and the highest liquid product yield was obtained at 475 C. Liquid products obtained under the most suitable conditions were characterized by elemental analyses, FT-IR, {sup 1}H NMR and GC-MS techniques. The results show that it is possible to obtain liquid products that are comparable to petroleum fuels and valuable chemical feedstock from bicycle/rickshaw tire wastes if the pyrolysis conditions are chosen accordingly. (author)

Consumers’ preferences for “bicycle poultry” in Benin

DEFF Research Database (Denmark)

Sodjinou, Epiphane; Henningsen, Arne; Koudande, Delphin O.

2015-01-01

Village poultry, also termed "bicycle poultry," is produced in scavenging farming systems and is a chewy meat with a low fat content, and constitutes an important source of meat in many African countries. This study investigates consumers’ preferences regarding the physical traits of these birds...... (notably chickens, ducks and guinea fowl) in the Republic of Benin. For this purpose, we applied the hedonic price method on field data collected from retailers in four urban and five rural markets. We found that meatier drake and meatier guinea fowl with white plumage are preferred by consumers who...

Cardiopulmonary exercise testing – effective method for evaluation and recommendation of individualized exercise training in patients with metabolic syndrome

Directory of Open Access Journals (Sweden)

Claudiu Avram

2011-12-01

Full Text Available The present study aims to emphasize the role of cardiopulmonary exercise training (CPET in evaluation and recommendation of individualized exercise training in patients with a metabolic syndrome. Methods: We performed a prospective longitudinal study of 9 months. The study group consisted of 28 young patients (21.3±3.1 years old without contraindications to exercise, previously diagnosed with metabolic syndrome according to NCEP-ATPIII criteria. All patients were evaluating at baseline and after 3 months of intervention and at the end of the study (after 9 months. The evaluation consists in performing a CPET on bicycle ergometer in which subjects were monitored in terms of cardiac and respiratory parameters. The CPET results allow us to establish the range of effort intensity in which the patient should exercise in order to burn calories and achieve the maximum fat oxidation rate. All patients benefit from an intensive interval exercise training programme, supervised and guided by a physical therapist. Exercise training consisted in 50 minutes sessions, 3 times per week, at intensive endurance training zone (in the range of anaerobic threshold, completed by 1 minute interval in the range between anaerobic threshold (AT and respiratory compensation point (RCP, for every 5 minutes of training. Results: After 9 months of intervention we noticed an improvement of abdominal obesity (waist circumference decreased from 98.98±10.14 cm to 89.54±12.32 cm, p<0.001, physical fitness (V’O2peak increased from 1.83±0.33 l/min to 2.13±0.4 l/min, p<0.001 and endurance (Oxygen uptake in the range of anaerobic treshold increase from 1.27±0.27 l/min to 1.55±0.31 l/min, p<0.001. Conclusions: Cardiopulmonary exercise testing together with training zones determinations is a useful tool for assessing the exercise capacity and drawing up individual workouts. Active and closely monitored intervention by individualized exercise training programmes leads to

Does the Intramolecular Hydrogen Bond Affect the Spectroscopic Properties of Bicyclic Diazole Heterocycles?

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Paweł Misiak

2018-01-01

Full Text Available The formation of an intramolecular hydrogen bond in pyrrolo[1,2-a]pyrazin-1(2H-one bicyclic diazoles was analyzed, and the influence of N-substitution on HB formation is discussed in this study. B3LYP/aug-cc-pVDZ calculations were performed for the diazole, and the quantum theory of atoms in molecules (QTAIM approach as well as the natural bond orbital (NBO method was applied to analyze the strength of this interaction. It was found that the intramolecular hydrogen bond that closes an extra ring between the C=O proton acceptor group and the CH proton donor, that is, C=O⋯H–C, influences the spectroscopic properties of pyrrolopyrazine bicyclic diazoles, particularly the carbonyl frequencies. The influence of N-substitution on the aromaticity of heterocyclic rings is also discussed in this report.

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

Science.gov (United States)

Buresh, Robert

2018-05-01

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

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

African Journals Online (AJOL)

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

Trends in the incidence and outcomes of bicycle-related injury in the emergency department: A nationwide population-based study in South Korea, 2012-2014.

Directory of Open Access Journals (Sweden)

Youn-Jung Kim

Full Text Available This study aimed to examine trends in the incidence and outcomes of bicycle-related injuries in emergency departments (ED in South Korea.We analysed data from the National Emergency Department Information System database for adult patients (≥20 years with bicycle-related injuries presenting to EDs in South Korea between January 2012 and December 2014. Riders and bicycle passengers whose injuries were associated with bicycle use were included. Serious outcomes were defined as death at the ED, need for emergency operation, or intensive care unit admission.The number of people who commute to work by bicycle increased by 36% from 205,100 in 2005 to 279,544 in 2015. Of 529,278 traffic-related trauma cases, 58,352 (11.0% were bicycle-related, which increased from 7,894 (10.2% in the first half of 2012 to 12,882 (12.2% in the second half of 2014 (p < 0.001. However, the proportion of serious outcomes decreased from 5.0% to 4.2% during the study period (p < 0.001. Serious outcomes were most frequent in the elderly (65-74 years and older elderly (≥75 years groups and decreased for all but the elderly age group from 10.3% to 9.8% (p = 0.204. The helmet use rate increased from 14.2% to 20.3% (p < 0.001 but was the lowest in the older elderly group (3.6% without change during the study period (from 4.7% to 3.7%, p = 0.656. A lack of helmet use was significantly associated with serious outcomes (odds ratio, 1.811; 95% confidence interval, 1.576-2.082.Although the incidence of bicycle-related injuries increased, the proportion of serious outcomes decreased, possibly due to increased helmet use. Public education on safety equipment use is required, especially in elderly populations.

Hypertension in master endurance athletes.

Science.gov (United States)

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

1998-11-01

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

ANTHROPOLOGY DIMENSIONS AS INDEPENDENT AEROBIC ENDURANCE

Directory of Open Access Journals (Sweden)

Ratko Pavlović

2009-11-01

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

Pseudoaneurysm of the Radial Artery After a Bicycle Fall.

Science.gov (United States)

Ratschiller, Thomas; Müller, Hannes; Schachner, Thomas; Zierer, Andreas

2018-07-01

We report a case of a 64-year-old man who developed a painful pulsatile mass in the distal forearm after a bicycle fall with fracture of the wrist. Ultrasonography confirmed a 2.5-cm large pseudoaneurysm of the radial artery. The patient underwent surgical exploration. The pseudoaneurysm was resected and the defect in the arterial wall was reconstructed with an autologous saphenous vein patch. We suggest that the double arterial supply of the hand should be preserved whenever possible.

Physical fitness differences of students with different cardiorespiratory endurance levels

Directory of Open Access Journals (Sweden)

Stojanović Darko

2016-01-01

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

Bamboo Bicycle – Past or Future?

Directory of Open Access Journals (Sweden)

Suzana Jakovljević

2016-01-01

Full Text Available In this article the experiment was carried out to establish tensile strength values of two different bamboo species, which are obtained by the static tensile test. The tensile strength results of two tested species Tonkin Cane and Ku Zhu bamboo are presented and compared with traditional materials used for bicycle frame to determine their suitability for designing a frame. Physiology and other properties of bamboo were elaborated as well. The purpose of this study was to gain more knowledge on bamboo and prove his suitability in use as an alternative for ecologically unacceptable materials. Therefore, application of the natural materials is essential for the sustainable development. The fact that they have unlimited resources the use of bamboo has great potential and this article explains why.

Exercise therapy improves aerobic capacity of inpatients with major depressive disorder.

Science.gov (United States)

Kerling, Arno; von Bohlen, Anne; Kück, Momme; Tegtbur, Uwe; Grams, Lena; Haufe, Sven; Gützlaff, Elke; Kahl, Kai G

2016-06-01

Unipolar depression is one of the most common diseases worldwide and is associated with a higher cardiovascular risk partly due to reduced aerobic capacity. Therefore, the aim of our study was to examine whether a structured aerobic training program can improve aerobic capacity in inpatients with MDD (major depressive disorder). Overall, 25 patients (13 women, 12 men) diagnosed with MDD were included in the study. Parameters of aerobic capacity, such as maximum performance, maximum oxygen consumption, and VAT (ventilatory anaerobic threshold), were assessed on a bicycle ergometer before and 6 weeks after a training period (three times per week for 45 min on two endurance machines). In addition, a constant load test was carried out at 50% of the maximum performance prior to and after the training period. The performance data were compared with 25 healthy controls matched for sex, age, and body mass index before and after the training period. Compared to controls, patients with MDD had significantly lower aerobic capacity. After training, there was a significant improvement in their performance data. A significant difference remained only for VAT between patients with MDD and healthy controls. With regard to the coincidence of MDD with cardiovascular and cardiometabolic disorders, a structured supervised exercise program carried out during hospitalization is a useful supplement for patients with MDD.

Physical activity in physiotherapy and physical education high school students

Directory of Open Access Journals (Sweden)

Mihailova A.

2014-01-01

Full Text Available A term of health-related physical fitness became topical with four its components: aerobic and/or cardiovascular fitness, body composition, abdominal muscle strength and endurance, and lower back and hamstring flexibility. Complex evaluation of health-related physical fitness and physical activity (PA may show a wider insight in health promotion and disease prevention. The aim of this study was to evaluate physical activity relation to health-related physical fitness in Physiotherapy (PT and Physical Education (PE students. Final study sample consisted of 67 students (46 women and 21 men (aged 21.61 ± 0.71. All participants filled in International Physical Activity Questionnaire. Health-related physical testing included: 1 body composition evaluation, 2 abdominal muscles strength tests, 3 dynamometry, 4 hamstring muscles and m. quadratus lumborum elasticity evaluation tests, 5 bicycle ergometer test (anaerobic threshold, maximal oxygen consumption. Results showed that most students had normal body composition parameters (BMI, body fat, muscle mass, body water in both genders and study programs. Women were less physically active that men, and PA duration was higher in PE students. PT students had higher body composition values, lower cardiorespiratory fitness parameters and lower handgrip strength in both hands than PE students. Greater PA generally implies a higher level of health-related physical fitness. PA significantly positively affects body composition, upper m. rectus abdominisstrength, grip strength and aerobic capacity.

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

African Journals Online (AJOL)

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

Harvesting Energy from the Counterbalancing (Weaving Movement in Bicycle Riding

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Shashank Priya

2012-07-01

Full Text Available Bicycles are known to be rich source of kinetic energy, some of which is available for harvesting during speedy and balanced maneuvers by the user. A conventional dynamo attached to the rim can generate a large amount of output power at an expense of extra energy input from the user. However, when applying energy conversion technology to human powered equipments, it is important to minimize the increase in extra muscular activity and to maximize the efficiency of human movements. This study proposes a novel energy harvesting methodology that utilizes lateral oscillation of bicycle frame (weaving caused by user weight shifting movements in order to increase the pedaling force in uphill riding or during quick speed-up. Based on the 3D motion analysis, we designed and implemented the prototype of an electro-dynamic energy harvester that can be mounted on the bicycle’s handlebar to collect energy from the side-to-side movement. The harvester was found to generate substantial electric output power of 6.6 mW from normal road riding. It was able to generate power even during uphill riding which has never been shown with other approaches. Moreover, harvesting of energy from weaving motion seems to increase the economy of cycling by helping efficient usage of human power.

The Dutch Bicycle Master Plan and road safety : measures to be taken.

NARCIS (Netherlands)

Noordzij, P.C. & Blokpoel, A.

1998-01-01

The Bicycle Master Plan was launched in 1990 and concluded in 1996. To mark its conclusion, a study was carried out to assess developments in road safety for cyclists. An overview of future measures was also compiled. Since 1950, there have been three broad periods: (1) 1950-1975: an increase in the

踏车而飞：自行车与中国骑车人（1868-1949 年）[A History of the Bicycle and Chinese Cyclists, 1868-1949

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Tao Xu

2012-06-01

Full Text Available Of the many “exotic” commodities from the West that have changed the lifestyle of the Chinese people over the course of the past two centuries, the bicycle stands out as a prominent example. It has so thoroughly transformed the Chinese mode of transportation that China in the late twentieth century was known as “the kingdom of bicycles.” This essay examines the history of that transformation. The first recorded importation of bicycles to Shanghai took place in 1868. Initially rejected by prospective customers for their incompatibility with Chinese cultural and social conventions, bicycles eventually gained visibility on the streets of many cities and suburbs. The bicycle meant many different things to different sectors of the population, and the social meaning of the bike also changed over time.The first section of this article offers an overview of modern Chinese cyclists. The author argues that early adopters were Manchu aristocrats and wealthy individuals who sported their bicycles on bumpy roads for the sheer enjoyment of the bike’s exotic quality. The second section of the article examines the story of Pu Yi, the last Qing ruler, and bikers in the Forbidden City. The third section examines women bike riders in China. The author presents evidence to show that cycling carried no liberating connotations for modern Chinese women. By the 1930s, bicycles had lost their exotic quality. They also came to be associated with the comings and goings of urban working people, when cars became the vehicles of the social and economic elite. The outbreak of the Sino-Japanese War (1937-45 created a petroleum shortage that grounded all private cars. Bicycles then emerged as the common mode of transportation for the rich as well as the poor, men as well as women. It was the war that laid the foundation for China’s modern transformation into a nation of bicycles.Note: Article is in Chinese.

Particulates and noise exposure during bicycle, bus and car commuting: A study in three European cities.

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Okokon, Enembe O; Yli-Tuomi, Tarja; Turunen, Anu W; Taimisto, Pekka; Pennanen, Arto; Vouitsis, Ilias; Samaras, Zissis; Voogt, Marita; Keuken, Menno; Lanki, Timo

2017-04-01

In order to curb traffic-related air pollution and its impact on the physical environment, contemporary city commuters are encouraged to shift from private car use to active or public transport modes. However, personal exposures to particulate matter (PM), black carbon and noise during commuting may be substantial. Therefore, studies comparing exposures during recommended modes of transport versus car trips are needed. We measured personal exposure to various-sized particulates, soot, and noise during commuting by bicycle, bus and car in three European cities: Helsinki in Finland, Rotterdam in the Netherlands and Thessaloniki in Greece using portable monitoring devices. We monitored commonly travelled routes in these cities. The total number of one-way trips yielding data on any of the measured parameters were 84, 72, 94 and 69 for bicycle, bus, closed-window car and open-window car modes, respectively. The highest mean PM 2.5 (85µg/m 3 ), PM 10 (131µg/m 3 ), black carbon (10.9µg/m 3 ) and noise (75dBA) levels were recorded on the bus, bus (again), open-window car and bicycle modes, respectively, all in Thessaloniki, PM and soot concentrations were generally higher during biking and taking a bus than during a drive in a a car with closed windows. Ratios of bike:car PM 10 ranged from 1.1 in Thessaloniki to 2.6 in Helsinki, while bus:car ratios ranged from in 1.0 in Rotterdam to 5.6 in Thessaloniki. Higher noise levels were mostly recorded during bicycle rides. Based on our study, active- and public-transport commuters are often at risk of higher air pollution and noise exposure than private car users. This should be taken into account in urban transportation planning. Copyright © 2017 Elsevier Inc. All rights reserved.

Endurance training increases the efficiency of rat skeletal muscle mitochondria.

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

2016-10-01

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

Mental toughness latent profiles in endurance athletes.

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Joanna S Zeiger

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

Carbohydrate Dependence During Prolonged, Intense Endurance Exercise.

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Hawley, John A; Leckey, Jill J

2015-11-01

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

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

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Jeukendrup, Asker E

2011-01-01

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

Master athletes are extending the limits of human endurance

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Romuald Lepers

2016-12-01

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

Users, uses and potential of electric-assisted bicycles - Results of a survey in the Canton of Geneva; Usagers, usages et potentiel des velos a assistance electrique. Resultats d'une enquete menee dans le canton de Geneve

Energy Technology Data Exchange (ETDEWEB)

Bernardoni, S.; Iseli, A.; Munafo, S.

2009-12-15

The municipal, regional and national authorities wanted to assess the potential of electric-assisted bicycles in the Geneva region. A survey performed by the University of Geneva is reported. The following points were investigated: (i) Who uses an electric bicycle? (ii) How is an electric bicycle used? (iii) Why is an electric bicycle purchased? (iv) How many people could potentially use an electric bicycle in the Geneva region? (v) How much energy would be saved and what fraction of the carbon dioxide emissions would be avoided thanks to electric bicycles in the region? Some interesting results: Most current electric bicycle users are women and live in Geneva outskirts. Most users have an academic degree or equivalent and have a good job. Most of them have also a car and other bicycles without electric motor. The main uses of electric bicycles is commuting between house and job locations, leisure activities and shopping. The average annual distance per electric bicycle is about 3000 km. The majority of the electric bicycles in use are limited to 25 km/h and can be driven without any license. The users wish an extension of the bicycle track network along the roads and of the protected parking areas. The number of potential users in the City of Geneva is estimated to 9% or 15,600 new users and to 10% or 43,000 new users in the suburbs. In 2030, 7,500,000 litres-equivalent of gasoline could be annually saved in the region and more than 16,000 tons CO{sub 2} emissions avoided.

Physical Activity Might Be of Greater Importance for Good Spinal Control Than If You Have Had Pain or Not: A Longitudinal Study.

Science.gov (United States)

Aasa, Ulrika; Lundell, Sara; Aasa, Björn; Westerståhl, Maria

2015-12-01

Longitudinal design. A cohort followed in 3 waves of data collection. The aim of the study was to describe the relationships between the performance of 2 tests of spinal control at the age of 52 years and low back pain, physical activity level, and fitness earlier in life, as well as to describe the cross-sectional relationships between these measures. Altered spinal control has been linked to pain; however, other stimuli may also lead to inability to control the movements of the spine. Participants answered questions about physical activity and low back pain, and performed physical fitness tests at the age of 16, 34, and 52 years. The fitness test battery included tests of endurance in the back and abdominal muscles, a submaximal bicycle ergometer test to estimate maximal oxygen uptake, and measurements of hip flexion, thoracic spine flexibility, and anthropometrics. Two tests were aggregated to a physical fitness index. At the age of 52, also 2 tests of spinal control, the standing Waiter's bow (WB) and the supine double leg lower (LL) were performed. Logistic regression analyses showed that higher back muscle endurance at the age of 34 years could positively predict WB performance at 52 years and higher physical fitness at the age of 34 could positively predict LL performance at 52 years. Regarding cross-sectional relationships, an inability to perform the WB correctly was associated with lower physical fitness, flexibility and physical activity, and larger waist circumference. An inability to correctly perform the LL was associated with lower physical fitness. One-year prevalence of pain was not significantly associated with WB or LL test performance. An active life resulting in higher physical fitness is related to better spinal control in middle-aged men and women. This further strengthens the importance of physical activity throughout the life span. 3.

Peculiarities of endurance development for first year students

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A.G. Pochernina

2014-06-01

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

Energy requirements for racing endurance sled dogs*

OpenAIRE

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

2014-01-01

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

Evaluating Bicycle, Pedestrian, Transit and Economic Data Collection Needs and Measures of Effectiveness in Pennsylvania

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2018-02-06

The purpose of this research project was to evaluate the current data collection procedures for bicycle and pedestrian projects utilized by the Pennsylvania Department of Transportation (PennDOT) and Pennsylvania's Metropolitan Planning Organizations...

Pedaling into high gear for bicycle policy in Canada : lessons from bike summit 2008 in Toronto

International Nuclear Information System (INIS)

2008-01-01

The 2008 bike summit provided a forum for the discussion of international and Canadian best practices related to bicycles and bicycling policy. The aim of the summit was to assist communities across Canada to improve conditions for cycling in the urban environment and help to generate a cultural shift towards greater acceptance of cycling on roads. This paper discussed lessons learned during the summit and outlined new methods of improving cycling in communities. The City of London has recently increased the amount of cyclists using its roads by 200 per cent. Cycling infrastructure is more affordable than constructing major public transit or road infrastructure. Savings in healthcare costs will be accrued over time as a result of the healthier lifestyles promoted by regular cycling activity. Bicycle trips can help to alleviate over-demand on heavy transit routes. Encouraging commuters to cycle will also reduce the amounts of greenhouse gases (GHGs) emitted in urban areas. Lane width reductions will help to reduce speeds as drivers are forced to pay more attention when driving. Public bike sharing programs and bike stations are now being used in many North American cities. It was concluded that strong advocacy is needed to ensure the growth and acceptance of cycling in urban centres. 23 figs

Association between neighborhood walkability and GPS-measured walking, bicycling and vehicle time in adolescents

DEFF Research Database (Denmark)

Carlson, Jordan A.; Saelens, Brian E.; Kerr, Jacqueline

2015-01-01

, intersection density, retail density, entertainment density and walkability were derived using GIS. Minutes/day of walking, bicycling and vehicle time were derived from processing algorithms applied to GPS. Accelerometers estimated total daily moderate-to-vigorous physical activity (MVPA). Models were adjusted...

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

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

2009-09-15

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

Pedaling rate is an important determinant of human oxygen uptake during exercise on the cycle ergometer.

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Formenti, Federico; Minetti, Alberto E; Borrani, Fabio

2015-09-01

Estimation of human oxygen uptake (V˙o2) during exercise is often used as an alternative when its direct measurement is not feasible. The American College of Sports Medicine (ACSM) suggests estimating human V˙o2 during exercise on a cycle ergometer through an equation that considers individual's body mass and external work rate, but not pedaling rate (PR). We hypothesized that including PR in the ACSM equation would improve its V˙o2 prediction accuracy. Ten healthy male participants' (age 19-48 years) were recruited and their steady-state V˙o2 was recorded on a cycle ergometer for 16 combinations of external work rates (0, 50, 100, and 150 W) and PR (50, 70, 90, and 110 revolutions per minute). V˙o2 was calculated by means of a new equation, and by the ACSM equation for comparison. Kinematic data were collected by means of an infrared 3-D motion analysis system in order to explore the mechanical determinants of V˙o2. Including PR in the ACSM equation improved the accuracy for prediction of sub-maximal V˙o2 during exercise (mean bias 1.9 vs. 3.3 mL O2 kg(-1) min(-1)) but it did not affect the accuracy for prediction of maximal V˙o2 (P > 0.05). Confirming the validity of this new equation, the results were replicated for data reported in the literature in 51 participants. We conclude that PR is an important determinant of human V˙o2 during cycling exercise, and it should be considered when predicting oxygen consumption. © 2015 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

Efficiency of Choice Set Generation Methods for Bicycle Routes

DEFF Research Database (Denmark)

Halldórsdóttir, Katrín; Rieser-Schüssler, Nadine; W. Axhausen, Kay

behaviour, observed choices and alternatives composing the choice set of each cyclist are necessary. However, generating the alternative choice sets can prove challenging. This paper analyses the efficiency of various choice set generation methods for bicycle routes in order to contribute to our...... travelling information with GPS loggers, compared to self-reported RP data, is more accurate geographic locations and routes. Also, the GPS traces give more reliable information on times and prevent trip underreporting, and it is possible to collect information on many trips by the same person without...

Individual- and area-level disparities in access to the road network, subway system and a public bicycle share program on the Island of Montreal, Canada.

Science.gov (United States)

Fuller, Daniel; Gauvin, Lise; Kestens, Yan

2013-02-01

Few studies have examined potential disparities in access to transportation infrastructures, an important determinant of population health. To examine individual- and area-level disparities in access to the road network, public transportation system, and a public bicycle share program in Montreal, Canada. Examining associations between sociodemographic variables and access to the road network, public transportation system, and a public bicycle share program, 6,495 adult respondents (mean age, 48.7 years; 59.0 % female) nested in 33 areas were included in a multilevel analysis. Individuals with lower incomes lived significantly closer to public transportation and the bicycle share program. At the area level, the interaction between low-education and low-income neighborhoods showed that these areas were significantly closer to public transportation and the bicycle share program controlling for individual and urbanicity variables. More deprived areas of the Island of Montreal have better access to transportation infrastructure than less-deprived areas.

Passion and Pacing in Endurance Performance.

Science.gov (United States)

Schiphof-Godart, Lieke; Hettinga, Florentina J

2017-01-01

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

Environmental and social life cycle assessment of bamboo bicycle frames made in Ghana

NARCIS (Netherlands)

Agyekum, Eric Ofori; Fortuin, K.P.J.; Harst-Wintraecken, van der E.J.M.

2017-01-01

This case study assessed the environmental and social impact of bicycle frames made from wild Ghanaian bamboo. The environmental life cycle assessment (LCA) of the bamboo frame was compared to the LCA results of an aluminium frame and a steel frame. The results show that the overall environmental

Structure-activity relationship of antiparasitic and cytotoxic indoloquinoline alkaloids, and their tricyclic and bicyclic analogues.

Science.gov (United States)

Van Baelen, Gitte; Hostyn, Steven; Dhooghe, Liene; Tapolcsányi, Pál; Mátyus, Péter; Lemière, Guy; Dommisse, Roger; Kaiser, Marcel; Brun, Reto; Cos, Paul; Maes, Louis; Hajós, György; Riedl, Zsuzsanna; Nagy, Ildikó; Maes, Bert U W; Pieters, Luc

2009-10-15

Based on the indoloquinoline alkaloids cryptolepine (1), neocryptolepine (2), isocryptolepine (3) and isoneocryptolepine (4), used as lead compounds for new antimalarial agents, a series of tricyclic and bicyclic analogues, including carbolines, azaindoles, pyrroloquinolines and pyrroloisoquinolines was synthesized and biologically evaluated. None of the bicyclic compounds was significantly active against the chloroquine-resistant strain Plasmodium falciparum K1, in contrast to the tricyclic derivatives. The tricyclic compound 2-methyl-2H-pyrido[3,4-b]indole (9), or 2-methyl-beta-carboline, showed the best in vitro activity, with an IC(50) value of 0.45 microM against P. falciparum K1, without apparent cytotoxicity against L6 cells (SI>1000). However, this compound was not active in the Plasmodium berghei mouse model. Structure-activity relationships are discussed and compared with related naturally occurring compounds.

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

Science.gov (United States)

Scofield, Kirk L; Hecht, Suzanne

2012-01-01

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

Anti-gravity training improves walking capacity and postural balance in patients with muscular dystrophy

DEFF Research Database (Denmark)

Berthelsen, Martin Peter; Husu, Edith; Christensen, Sofie Bouschinger

2014-01-01

of their weakness. We investigated the functional effects of combined aerobic and strength training in patients with Becker and limb-girdle muscular dystrophies with knee muscle strength levels as low as 3% of normal strength. Eight patients performed 10weeks of aerobic and strength training on an anti...... affected patients with Becker and limb-girdle muscular dystrophies.......Recent studies in patients with muscular dystrophies suggest positive effects of aerobic and strength training. These studies focused training on using bicycle ergometers and conventional strength training, which precludes more severely affected patients from participating, because...

Depression, anxiety and quality of life scores in seniors after an endurance exercise program

Directory of Open Access Journals (Sweden)

Antunes Hanna Karen Moreira

2005-01-01

Full Text Available OBJECTIVE: Mood disorders are a frequent problem in old age, and their symptoms constitute an important public health issue. These alterations affect the quality of life mainly by restricting social life. The participation in a regular exercise program is an effective way of reducing or preventing the functional decline associated with aging. The aim of the present study was to examine the effects of fitness-endurance activity (at the intensity of Ventilatory Threshold 1 (VT-1 in depression, anxiety and quality of life scores in seniors. METHODS: The study involved 46 sedentary seniors aged 60-75 (66.97 ± 4.80 who were randomly allocated to two groups: 1 Control group, which was neither asked to vary their everyday activities nor to join a regular physical fitness program; and 2 Experimental group, whose members took part in an aerobic fitness program consisting of ergometer cycle sessions 3 times a week on alternate days for six months working at a heart rate corresponding to ventilatory threshold (VT-1 intensity. Subjects were submitted to a basal evaluation using the geriatric depression screening scale - GDS, STAI trait/state (anxiety scale and SF-36 (quality of life scale. RESULTS: Comparing the groups after the study period, we found a significant decrease in depressive and anxiety scores and an improvement in the quality of life in the experimental group, but no significant changes in the control group. CONCLUSION: The data suggest that an aerobic exercise program at VT-1 intensity suffices to promote favorable modifications in depressive and anxiety scores to improve the quality of life in seniors.

Mental toughness latent profiles in endurance athletes.

Science.gov (United States)

Zeiger, Joanna S; Zeiger, Robert S

2018-01-01

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

Influence of stress and recovery on endurance performance indicators

NARCIS (Netherlands)

Otter, Ruby; Brink, Michel; Lemmink, Koen

2016-01-01

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

CEPRAM: Compression for Endurance in PCM RAM

OpenAIRE

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

2017-01-01

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

Endurance training at altitude.

Science.gov (United States)

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

2009-01-01

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

Endurance test of DUPIC irradiation test rig-003

Energy Technology Data Exchange (ETDEWEB)

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

2001-04-01

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

Endurance test for DUPIC capsule

International Nuclear Information System (INIS)

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

1999-07-01

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

Skin autofluorescence is associated with arterial stiffness and insulin level in endurance runners and healthy controls - Effects of aging and endurance exercise.

Science.gov (United States)

Couppé, Christian; Dall, Christian Have; Svensson, Rene Brüggebusch; Olsen, Rasmus Huan; Karlsen, Anders; Praet, Stephan; Prescott, Eva; Magnusson, S Peter

2017-05-01

Life-long regular endurance exercise yields positive effects on cardiovascular and metabolic function, disease and mortality rate. Glycation may be a major mechanism behind age-related diseases. However, it remains unknown if skin autofluorescence (SAF), which reflects glycation, is related to arterial and metabolic function in life-long endurance runners and sedentary controls. Healthy elderly men: 15 life-long endurance runners (OT) (64±4years) and 12 old untrained (OU) (66±4years), and healthy young men; ten young athletes (YT) (26±4years) matched to OT for running distance, and 12 young untrained (YU) (24±3years) were recruited. Endothelial function (reactive hyperemia index, RHI) and arterial stiffness (augmentation index, AI@75 and AI) were measured by an operator-independent PAT 2000. SAF was non-invasively determined using an autofluorescence spectrometer. For AI@75 there was an effect of age (page correction (both r 2 =0.19, paging and pathology). Surprisingly, endurance running only had modest effects on cardiovascular function compared to lean healthy controls. Copyright © 2017 Elsevier Inc. All rights reserved.

Understanding the preconditions for revitalizing bicycle transport in Beijing, with a reference study from Copenhagen

DEFF Research Database (Denmark)

Zhao, Chunli

of transport and planning research by strengthening the knowledge base on the conditions that affect the use of bicycles in the megacities of developing world as well as by exploring the factors governing the populations’ attitudes towards their future mobility. Furthermore, the study contributes...... for accelerating the identification of effective solutions in specific cities and in specific planning cultures. For Beijing residents, the bicycle is currently a mode of transport for those with limited education and limited financial resources. The young Beijingers are least likely to cycle. This age difference...... is likely to be partly due to a cohort difference and, thus, indicates a growing problem for cycling in Beijing. On the other hand, clear associations with density and other urban form variables indicate that the proximity environment and urban development policies can also affect cycling. The effect...

Triacilglicerol intramuscular: um importante substrato energético para o exercício de endurance Triacilglicerol intramuscular: un importante substrato energético para el ejercicio de endurance Intramuscular triacylglycerol: an important energetic substrate for endurance exercise

Directory of Open Access Journals (Sweden)

Mônica Aparecida Belmonte

2005-04-01

Full Text Available Os ácidos graxos são uma importante fonte de energia para exercício de endurance. Os ácidos graxos plasmáticos encontram-se disponíveis para as fibras musculares sob a forma de ácidos graxos associados à albumina ou agregados à molécula de triacilglicerol (TAG encontrada nas lipoproteínas. Entretanto, além dessas fontes plasmáticas, a hidrólise do TAG encontrado no músculo também pode contribuir com a oferta de ácidos graxos durante o exercício de endurance. O objetivo do presente trabalho foi realizar uma extensa revisão da literatura sobre a importância do TAG intramuscular como substrato energético. A revisão da literatura sugere que a contribuição dos estoques endógenos de TAG durante a realização do exercício de endurance é bastante relevante. Além disso, pode-se concluir que uma adaptação induzida pelo treinamento de endurance é o aumento dos estoques intramusculares de TAG. Após o treinamento de endurance, também é observado aumento na capacidade de utilização desses estoques. Apesar de parecer importante, a contribuição do TAG intramuscular ainda é motivo de controvérsia na literatura. Essa discrepância de resultados está relacionada às metodologias empregadas para estimar a sua oxidação no exercício. A fim de esgotar este assunto de maneira apropriada, mais pesquisas, com novos métodos (ex.: utilização de isótopos, ressonância magnética nuclear e microscopia eletrônica, precisam ser conduzidas.Los ácidos grasos son una fuente importante de energía para el ejercicio de endurance. Los ácidos grasos plasmáticos se encuentran disponibles en las fibras musculares bajo la forma de ácido graso asociado a la albúmina o agregados a la molécula del triacilglicerol (TAG encontrados en las lipoproteínas. Sin embargo, además de estos fuentes plasmáticas, la hidrólisis de los TAG encontrados en el músculo pueden contribuir también con la oferta de ácidos grasos durante el ejercicio

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

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Roy Jean-Sébastien

2011-01-01

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

Aging road user, bicyclist, and pedestrian safety : effective bicycling signs and preventing left-turn crashes.

Science.gov (United States)

2013-09-01

Task 1 of this report drivers' knowledge of various bicycle warning signs and pavement markings were assessed. In general knowledge was high. Share the Road and Three Foot Minimum signs were generally more quickly understood and recognized in version...

Interrelation of ST-segment depression during bicycle ergometry and extent of myocardial ischaemia by myocardial perfusion SPECT

International Nuclear Information System (INIS)

Muzzarelli, Stefano; Pfisterer, Matthias Emil; Zellweger, Michael Johannes; Mueller-Brand, Jan

2009-01-01

The aim of this study was to compare ST-segment depression (STD) during bicycle ergometry and extent of myocardial ischaemia assessed by myocardial perfusion SPECT (MPS) in a large patient cohort. Consecutive patients (n = 955) referred for MPS with bicycle ergometry and interpretable stress ECG were evaluated with respect to ECG and MPS findings of ischaemia. The maximal STD was recorded and exercise ECG was considered ischaemic if STD was horizontal or downsloping (≥1 mm). MPS was interpreted using a 20-segment model with a scale of 0 to 4. A summed stress (SSS), summed rest (SRS) and summed difference score (SDS = SSS-SRS, e.g. extent of ischaemia) were derived. Ischaemia was defined as an SDS ≥ 2. An exercise-induced STD was present in 215 patients (22%) and myocardial ischaemia on MPS was present in 366 patients (38%). The extent of ST-segment depression and the number of ECG leads with significant STD were each strongly and significantly associated with increasing severity of ischaemia and the number of coronary territories involved (p < 0.01 for all correlations). These data demonstrate a strong correlation between the extent of STD, number of ischaemic leads and severity of myocardial ischaemia as assessed by MPS during bicycle ergometry. (orig.)

Interrelation of ST-segment depression during bicycle ergometry and extent of myocardial ischaemia by myocardial perfusion SPECT

Energy Technology Data Exchange (ETDEWEB)

Muzzarelli, Stefano; Pfisterer, Matthias Emil; Zellweger, Michael Johannes [University Hospital Basel, Cardiology Department, Basel (Switzerland); Mueller-Brand, Jan [University Hospital Basel, Nuclear Medicine Department, Basel (Switzerland)

2009-11-15

The aim of this study was to compare ST-segment depression (STD) during bicycle ergometry and extent of myocardial ischaemia assessed by myocardial perfusion SPECT (MPS) in a large patient cohort. Consecutive patients (n = 955) referred for MPS with bicycle ergometry and interpretable stress ECG were evaluated with respect to ECG and MPS findings of ischaemia. The maximal STD was recorded and exercise ECG was considered ischaemic if STD was horizontal or downsloping ({>=}1 mm). MPS was interpreted using a 20-segment model with a scale of 0 to 4. A summed stress (SSS), summed rest (SRS) and summed difference score (SDS = SSS-SRS, e.g. extent of ischaemia) were derived. Ischaemia was defined as an SDS {>=} 2. An exercise-induced STD was present in 215 patients (22%) and myocardial ischaemia on MPS was present in 366 patients (38%). The extent of ST-segment depression and the number of ECG leads with significant STD were each strongly and significantly associated with increasing severity of ischaemia and the number of coronary territories involved (p < 0.01 for all correlations). These data demonstrate a strong correlation between the extent of STD, number of ischaemic leads and severity of myocardial ischaemia as assessed by MPS during bicycle ergometry. (orig.)

Bicycle and Car Share Schemes as Inclusive Modes of Travel? A Socio-Spatial Analysis in Glasgow, UK

Directory of Open Access Journals (Sweden)

Julie Clark

2016-06-01

Full Text Available Public bicycle and car sharing schemes have proliferated in recent years and are increasingly part of the urban transport landscape. Shared transport options have the potential to support social inclusion by improving accessibility: these initiatives could remove some of the barriers to car ownership or bicycle usage such as upfront costs, maintenance and storage. However, the existing evidence base indicates that, in reality, users are most likely to be white, male and middle class. This paper argues that there is a need to consider the social inclusivity of sharing schemes and to develop appropriate evaluation frameworks accordingly. We therefore open by considering ways in which shared transport schemes might be inclusive or not, using a framework developed from accessibility planning. In the second part of the paper, we use the case study of Glasgow in Scotland to undertake a spatial equity analysis of such schemes. We examine how well they serve different population groups across the city, using the locations of bicycle stations and car club parking spaces in Glasgow, comparing and contrasting bike and car. An apparent failure to deliver benefits across the demographic spectrum raises important questions about the socially inclusive nature of public investment in similar schemes.

The Bicycle Drawing Test: What Does It Measure in Developmentally Typical Children?

Science.gov (United States)

Cannoni, Eleonora; Di Norcia, Anna; Bombi, Anna Silvia; Di Giunta, Laura

2015-10-01

To verify the dimensionality of Bicycle Drawing Test (BDT), we applied the coding system of Greenberg, Rodriguez, and Sesta to bicycle drawings made by 295 boys and 320 girls (6-10 years old) with typical development, and submitted the data to item analysis, exploratory factor analysis, and confirmatory factor analysis. These analyses confirmed only two of the original four dimensions of the BDT: spatial reasoning and visual-motor control. The scores in these two factors were correlated with the Colored Progressive Matrices, the Rey Complex Figure (Copy and Memory) and with the teachers' ratings in mathematics, language, and drawing. The correlations, albeit moderate in magnitude, were consistent with the hypothesized convergent and discriminant validity. After checking for measurement invariance across gender and age, we conducted two analyses of variance, the first of which showed a significant difference between younger children (6-8 years old) and older children (9-10 years old); the analysis of variance by gender did not yield significant differences. These data enhance the usefulness of the BDT as a measure of separate cognitive components, but do not support its use as a measure of mechanical reasoning. © The Author(s) 2014.

GC/MS determination of bicyclic sesquiterpanes in crude oils and petroleum products

International Nuclear Information System (INIS)

Yang, C.; Wang, Z.; Hollebone, B.; Brown, C.E.; Landriault, M.

2008-01-01

A study was conducted in which sesquiterpanes, a component of crude oils and petroleum products, were identified and characterized in an effort to determine the feasibility of using them as biomarkers for fingerprinting and identifying unknown lighter petroleum product spills. The study compared the distributions of sesquiterpanes in different oils, oil distillation fractions and refined products, including light and mid-range distillate fuels, residual fuels and lubricating oils. Evaporative weathering effects on sesquiterpane distribution and concentration were quantitatively studied and several diagnostic indices of sesquiterpane were developed for oil correlation and differentiation. Bicyclic sesquiterpanes in crude oils and oil products have much different abundances and distributions. Therefore, the relevant sesquiterpane ratios are different. Bicyclic sesquiterpanes are mostly partitioned into the medium distillation fractions. The study showed that concentrations of sesquiterpanes in crude oil and diesel fuel increase in proportion with the increase of weathering percentages. Relevant diagnostic ratios therefore remained stable. It was concluded that C 15 and C 16 sesquiterpanes may be alternative internal tracers to provide a direct way to estimate the depletion of oils, particularly diesels, in oil spill investigations. 13 refs., 6 tabs., 4 figs

On the Effects of Tube Butting on the Structural Performance of Steel Bicycle Frames

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Derek Covill

2018-02-01

Full Text Available Previous studies have shown how finite element analysis (FEA can be used to support designers and frame builders in the selection of butted tubes to tune the stiffness and strength behaviour of steel bicycles. The aim of this paper was therefore to analyse the effects of tube butting on the stiffness, stress distribution and energy absorption behaviour of bicycle frames using numerical simulations. Butted tubes were shown to provide a highly effective means to decrease mass whilst producing a disproportionately small change in stress compared with a straight gauge tubeset with a maximum material condition although there was no added benefit in terms of stiffness or strain energy. Conversely, decreasing the wall thickness produced an increase in stress at the tube ends that was disproportionate to the change in mass. This work can now be extended to analyse a fuller set of butted profiles for a range of tube types.

Investigating the Views of Male Students on Using Bicycles Based on the Theory of Planned Behavior in Yazd University of Medical Sciences, 2012

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MH Baghianimoghadam

2014-11-01

Full Text Available Introduction: Today, it is somewhat possible for general Population to use bicycle as a means of transportation or sport. Physical activity is considered as an important strategy for the prevention and treatment of obesity and other critical metabolic diseases in the different ages of life. Since the Theory of Planned Behavior assesses perceived control beliefs about behaviors, it seems appropriate to study exercise. In the study, the views of male students - as a group which are affective on community norms- about bicycle use were investigated. Method: In this cross-sectional study 250 male students in Yazd University of Medical Sciences responded to a researcher made questionnaire which was designed for assessing their views about bicycle use, based on the Theory of Planned Behavior. The data were analyzed using SPSS v16. Results: The mean age of participants was 23. 01± 3. 83. Findings revealed that the scale means of the theory constructs were as follows: behavioral intention: 8. 54 ±3. 9, Attitude: 2. 97 ± 15. 2, subjective norm: 12. 1± 2. 9 and perceived behavioral control: 17. 5 ±4. 6. Regression analysis indicated that attitude and subjective norm explained 29. 7% of behavioral intention variations (P<0. 001. Conclusion: According to results which indicated that Attitude and subjective norm had more powerful relationship with and predictive power of behavioral intention about using bicycle it is recommended that cultural activities and interventions may be effective to promote using bicycle among students.

Upper Body Muscular Endurance Among Children 2-5 Years.

Science.gov (United States)

Gabbard, Carl P.; And Others

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

Recumbent vs. upright bicycles: 3D trajectory of body centre of mass, limb mechanical work, and operative range of propulsive muscles.

Science.gov (United States)

Telli, Riccardo; Seminati, Elena; Pavei, Gaspare; Minetti, Alberto Enrico

2017-03-01

Recumbent bicycles (RB) are high performance, human-powered vehicles. In comparison to normal/upright bicycles (NB) the RB may allow individuals to reach higher speeds due to aerodynamic advantages. The purpose of this investigation was to compare the non-aerodynamic factors that may potentially influence the performance of the two bicycles. 3D body centre of mass (BCoM) trajectory, its symmetries, and the components of the total mechanical work necessary to sustain cycling were assessed through 3D kinematics and computer simulations. Data collected at 50, 70, 90 110 rpm during stationary cycling were used to drive musculoskeletal modelling simulation and estimate muscle-tendon length. Results demonstrated that BCoM trajectory, confined in a 15-mm side cube, changed its orientation, maintaining a similar pattern across all cadences in both bicycles. RB displayed a reduced additional mechanical external power (16.1 ± 9.7 W on RB vs. 20.3 ± 8.8 W on NB), a greater symmetry on the progression axis, and no differences in the internal mechanical power compared to NB. Simulated muscle activity revealed small significant differences for only selected muscles. On the RB, quadriceps and gluteus demonstrated greater shortening, while biceps femoris, iliacus, and psoas exhibited greater stretch; however, aerodynamics still remains the principal benefit.

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

Science.gov (United States)

Timoshenko, D A; Bokser, O Ia

1986-01-01

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

The Enduring Value of the Physical Examination.

Science.gov (United States)

Zaman, Junaid A B

2018-05-01

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

The Bicycle Illusion: Sidewalk Science Informs the Integration of Motion and Shape Perception

Science.gov (United States)

Masson, Michael E. J.; Dodd, Michael D.; Enns, James T.

2009-01-01

The authors describe a new visual illusion first discovered in a natural setting. A cyclist riding beside a pair of sagging chains that connect fence posts appears to move up and down with the chains. In this illusion, a static shape (the chains) affects the perception of a moving shape (the bicycle), and this influence involves assimilation…

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Shoulder Girdle Muscles Endurance in Subjects with and without Impingement Syndrome

Directory of Open Access Journals (Sweden)

Afsoun Nodehi-Moghadam

2011-07-01

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

Endurance running performance in athletes with asthma.

Science.gov (United States)

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

1990-01-01

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

The effect of Sub-maximal exercise-rehabilitation program on cardio-respiratory endurance indexes and oxygen pulse in patients with spastic cerebral palsy

Directory of Open Access Journals (Sweden)

M Izadi

2006-05-01

Full Text Available Background: Physical or cardio-respiratory fitness are of the best important physiological variables in children with cerebral palsy (CP, but the researches on exercise response of individuals with CP are limited. Our aim was to determine the effect of sub-maximal rehabilitation program (aerobic exercise on maximal oxygen uptake, oxygen pulse and cardio- respiratory physiological variables of children with moderate to severe spastic cerebral palsy diplegia and compare with able-bodied children. Methods: In a controlled clinical trial study, 15 children with diplegia spastic cerebral palsy, were recruited on a voluntarily basis (experimental group and 18 subjects without neurological impairments selected as control group. In CP group, aerobic exercise program performed on the average of exercise intensity (144 beat per minute of heart rate, 3 times a week for 3 months. The time of each exercise session was 20-25 minutes. Dependent variables were measured in before (pretest and after (post test of rehabilitation program through Mac Master Protocol on Tantories cycle ergometer in CP group and compared with the control group. Results: The oxygen pulse (VO2/HR during ergometery protocol was significantly lower in CP group than normal group (P<0.05. No significant statistical difference in maximal oxygen uptake (VO2 max was found between groups. The rehabilitation program leads to little increase of this variable in CP group. After sub-maximal exercise in pretest and post test, the heart rate of patient group was greater than control group, and aerobic exercise leads to significant decrease in heart rate in CP patients(P<0.05. Conclusion: The patients with spastic cerebral palsy, because of high muscle tone, severe spasticity and involuntarily movements have higher energy cost and lower aerobic fitness than normal people. The rehabilitation exercise program can improve physiological function of muscle and cardio-respiratory endurance in these

Carbohydrate mouth rinse: does it improve endurance exercise performance?

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Painelli Vitor

2010-08-01

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

High-Intensity Interval Exercises' Acute Impact on Heart Rate Variability: Comparison Between Whole-Body and Cycle Ergometer Protocols.

Science.gov (United States)

Schaun, Gustavo Z; Del Vecchio, Fabrício B

2018-01-01

Schaun, GZ and Del Vecchio, FB. High-intensity interval exercises' acute impact on heart rate variability: comparison between whole-body and cycle ergometer protocols. J Strength Cond Res 32(1): 223-229, 2018-Study aimed to compare the effects of 2 high-intensity interval training (HIIT) protocols on heart rate variability. Twelve young adult males (23.3 ± 3.9 years, 177.8 ± 7.4 cm, 76.9 ± 12.9 kg) volunteered to participate. In a randomized cross-over design, subjects performed 2 HIIT protocols, 1 on a cycle ergometer (Tabata protocol [TBT]; eight 20-second bouts at 170% Pmax interspersed by 10-second rest) and another with whole-body calisthenic exercises (McRae protocol; eight 20-second all-out intervals interspersed by 10-second rest). Heart rate variability outcomes in the time, frequency, and nonlinear domains were assessed on 3 moments: (a) presession; (b) immediately postsession; and (c) 24 hours postsession. Results revealed that RRmean, Ln rMSSD, Ln high frequency (HF), and Ln low frequency (LF) were significantly reduced immediately postsession (p ≤ 0.001) and returned to baseline 24 h after both protocols. In addition, LF/HF ratio was reduced 24 h postsession (p ≤ 0.01) and SD2 was significantly lower immediately postsession only in TBT. Our main finding was that responses from heart rate autonomic control were similar in both protocols, despite different modes of exercise performed. Specifically, exercises resulted in a high parasympathetic inhibition immediately after session with subsequent recovery within 1 day. These results suggest that subjects were already recovered the day after and can help coaches to better program training sessions with such protocols.

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Long-distance mountain biking does not disturb the measurement of total, free or complexed prostate-specific antigen in healthy men.

Science.gov (United States)

Herrmann, Markus; Scharhag, Jürgen; Sand-Hill, Marga; Kindermann, Wilfried; Herrmann, Wolfgang

2004-03-01

Mechanical manipulation of the prostate is a generally accepted interfering factor for the measurement of prostate-specific antigen (PSA). However, only few studies have focused on common daily mechanical manipulations, such as bicycle riding. Furthermore, physical exercise is also supposed to modulate PSA serum concentration. Long-distance mountain biking is an excellent model to study the combined effect of mechanical prostate manipulation by bicycle riding and strenuous endurance exercise on total, free and complexed PSA (tPSA, fPSA, cPSA). We investigated tPSA, fPSA and cPSA in 42 healthy male cyclists (mean age 35+/-6 years) before and after a 120 km off-road mountain bike race. Blood sampling was done before, 15 min and 3 h after the race. Mean race time was 342+/-65 min. All athletes had normal serum levels of tPSA, fPSA or cPSA. None of these parameters was modified by the race. In healthy men the measurement of tPSA, fPSA and cPSA is not disturbed by preceding long distance mountain biking or endurance exercise. Based on the present data, there is no evidence for a recommendation to limit bicycle riding or physical activity before the measurement of tPSA, fPSA or cPSA.

Baroreflex buffering in sedentary and endurance exercise-trained healthy men.

Science.gov (United States)

Christou, Demetra D; Jones, Pamela Parker; Seals, Douglas R

2003-06-01

Baroreflex buffering plays an important role in arterial blood pressure control. Previous reports suggest that baroreflex sensitivity may be altered in endurance exercise-trained compared with untrained subjects. It is unknown, however, if in vivo baroreflex buffering is altered in the endurance exercise-trained state in humans. Baroreflex buffering was determined in 36 healthy normotensive men (18 endurance exercise-trained, 41+/-5 [SEM] years; 18 untrained, 41+/-4 years) by measuring the potentiation of the systolic blood pressure responses to a phenylephrine bolus and to incremental phenylephrine infusion during compared with before ganglionic blockade with trimethaphan. The exercise-trained men had a lower resting heart rate and higher maximal oxygen consumption and heart rate variability than the sedentary control subjects (all P=0.01). Mean levels and variability of blood pressure, cardiovagal baroreflex sensitivity (change in heart rate/change in systolic blood pressure), and basal muscle sympathetic nerve activity were not different in the two groups. The systolic blood pressure responses to phenylephrine were not different in the endurance-trained and untrained men before or during ganglionic blockade (P>0.6). Measures of baroreflex buffering with the use of a phenylephrine bolus (3.9+/-0.8 versus 4.0+/-0.7, trained versus untrained, P=0.85) and incremental infusion (2.8+/-0.4 versus 2.5+/-0.6, P=0.67) were similar in the two groups. Baroreflex buffering does not differ in endurance exercise-trained compared with untrained healthy men. These results support the concept that habitual vigorous endurance exercise does not modulate in vivo baroreflex buffering in healthy humans.

The Effects of Prompting and Reinforcement on Safe Behavior of Bicycle and Motorcycle Riders

Science.gov (United States)

Okinaka, Takeru; Shimazaki, Tsuneo

2011-01-01

A reversal design was used to evaluate the effects of vocal and written prompts as well as reinforcement on safe behavior (dismounting and walking bicycles or motorcycles on a sidewalk) on a university campus. Results indicated that an intervention that consisted of vocal and written prompts and reinforcement delivered by security guards was…

Endurance Factors Improve Hippocampal Neurogenesis and Spatial Memory in Mice

Science.gov (United States)

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

2011-01-01

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

Design and Analysis of a Novel Speed-Changing Wheel Hub with an Integrated Electric Motor for Electric Bicycles

Directory of Open Access Journals (Sweden)

Yi-Chang Wu

2013-01-01

Full Text Available The aim of this paper is to present an innovative electromechanical device which integrates a brushless DC (BLDC hub motor with a speed-changing wheel hub stored on the rear wheel of an electric bicycle. It combines a power source and a speed-changing mechanism to simultaneously provide functions of power generation and transmission for electric bicycles. As part of the proposed integrated device, the wheel hub consists of a basic planetary gear train providing three forward speeds including a low-speed gear, a direct drive, and a high-speed gear. Each gear is manually controlled by the shift control sleeve to selectively engage or disengage four pawl-and-ratchet clutches based on its clutching sequence table. The number of gear teeth of each gear element of the wheel hub is synthesized. The BLDC hub motor is an exterior-rotor-type permanent-magnet synchronous motor. Two-dimensional finite-element analysis (FEA software is employed to facilitate the motor design and performance analysis. An analysis of the power transmission path at each gear is provided to verify the validity of the proposed design. The results of this work are beneficial to the embodiment, design, and development of novel electromechanical devices for the power and transmission systems of electric bicycles.

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

Directory of Open Access Journals (Sweden)

Caren Lau

2015-01-01

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

Comparison of midterm results for the Talent and Endurant stent graft.

Science.gov (United States)

't Mannetje, Yannick W; Cuypers, Philippe W M; Saleem, Ben R; Bode, Aron S; Teijink, Joep A W; van Sambeek, Marc R H M

2017-09-01

Stent graft evolution is often addressed as a cause for improved outcomes of endovascular aneurysm repair for patients with an abdominal aortic aneurysm. In this study, we directly compared the midterm result of Endurant stent graft with its predecessor, the Talent stent graft (both Medtronic, Santa Rosa, Calif). Patient treated from January 2005 to December 2010 in a single tertiary center in The Netherlands with a Talent or Endurant stent graft were eligible for inclusion. Ruptured abdominal aortic aneurysms or patients with previous aortic surgery were excluded. The primary end point was the Kaplan-Meier estimated freedom from secondary interventions. Secondary end points were perioperative outcomes and indications for secondary interventions. In total, 221 patients were included (131 Endurant and 90 Talent). At baseline, the median aortic bifurcation was narrower for the Endurant (30 mm vs 39 mm; P Talent and Endurant, respectively. The estimated freedom from secondary interventions at 30 days, 1 year, 5 years, and 7 years was 94.3%, 89.4%, 72.2%, and 64.1% for Talent and 96.8%, 89.3%, 75.2%, and 69.2% for Endurant (P = .528). The indication for secondary interventions does differ; more patients required an intervention for a proximal neck-related complication (type Ia endoleak or migration) in the Talent group (18.2% vs 4.8%; P = .001), whereas more interventions for iliac limb stenosis were seen in the Endurant group (0.0% vs 4.8%; P = .044). In a binomial regression analysis, suprarenal angulation, infrarenal neck length, and type of stent graft were independent predictors of neck-related complications. Evolution from the Talent stent graft into the Endurant has resulted in significant reduction of infrarenal neck-related complications; on the other hand, iliac interventions increased. The overall midterm secondary intervention rate was comparable. Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.

Acid-promoted Bicyclization of Diaryl Alkynes: Synthesis of 2H-Indazoles with in situ Generated Diazonium Salt as Nitrogen Source.

Science.gov (United States)

Zhang, Cheng; Chang, Sailan; Dong, Shanliang; Qiu, Lihua; Xu, Xinfang

2018-06-08

An unprecedented transition-metal-free tandem bicyclization of diaryl alkynes has been disclosed, which provides a streamlined access to a range of polycyclic 2H-indazoles in high to excellent yields. The salient features of this reaction include readily available starting materials, good functional group compatibility, mild reaction conditions, no column chromatography, high bond-formation efficiency, and ease in further transformations. Notably, this is the first example for the synthesis of 2H-indazoles with in situ generated diazonium salt as the nitrogen source, and a mechanistic rationale involving an acid-promoted tandem diazonium salt formation/bicyclization process is discussed.

Soccer Endurance Development in Professionals

NARCIS (Netherlands)

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

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

Mixed maximal and explosive strength training in recreational endurance runners.

Science.gov (United States)

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

2014-03-01

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

A comparative study on the crystal structure of bicycle analogues to the natural phytotoxin helminthosporins

Science.gov (United States)

Barbosa, Luiz Cláudio de Almeida; Teixeira, Robson Ricardo; Nogueira, Leonardo Brandão; Maltha, Celia Regina Alvares; Doriguetto, Antônio Carlos; Martins, Felipe Terra

2016-02-01

Herein we described structural insights of a series of analogues to helminthosporin phytotoxins. The key reaction used to prepare the compounds corresponded to the [3 + 4] cycloaddition between the oxyallyl cation generated from 2,4-dibromopentan-3-one and different furans. Their structures were confirmed upon IR, NMR and X-ray diffraction analyses. While bicycles 7, 8 and 9 crystallize in the centrosymmetric monoclinic space group P21/c, compound 10 was solved in the noncentrosymmetric orthorhombic space group P212121. The solid materials obtained were shown to be racemic crystals (7, 8, 9) or racemic conglomerate (10). In all compounds, there is formation of a bicycle featured by fused tetrahydropyranone and 2,5-dihydrofuran rings. They adopt chair and envelope conformations, respectively. Crystal packing of all compounds is stabilized through C-H•••O contacts. Conformational aspects as well as similarities and differences among the crystal structures of the synthesized analogues are discussed.

Efficacy of controlled-release isosorbide-5-mononitrate as adjunctive treatment to beta-blocking agents in patients with stable angina pectoris

DEFF Research Database (Denmark)

Svendsen, Jesper Hastrup; Aldershvile, J; Abildgaard, U

1989-01-01

to a beta blocker. In bicycle ergometer exercise tests performed 4 h after study drug intake, total exercise time and time until 1-mm ST-depression increased significantly during both regimens as compared with placebo (p less than 0.05). However, only the 60-mg once-daily regimen was significantly better...... than placebo with regard to time until angina pectoris. The results indicate that ISMN-CR 60 mg once daily is effective as adjunctive to beta-blocker treatment, and nitrate tolerance appeared to develop during the twice-daily regimen. In 10 of the patients, the effect of additional sublingual...

No effect of glycogen level on glycogen metabolism during high intensity exercise

DEFF Research Database (Denmark)

Vandenberghe, Katleen; Hespel, P.; Eynde, Bart Vanden

1995-01-01

, either for 1 min 45 s (protocol 1; N = 18) or to exhaustion (protocol 2; N = 14). The exercise tests were preceded by either 5 d on a controlled normal (N) diet, or by 2 d of glycogen-depleting exercise accompanied by the normal diet followed by 3 d on a carbohydrate-rich (CHR) diet. In protocol 1......This study examined the effect of glycogen supercompensation on glycogen breakdown, muscle and blood lactate accumulation, blood-pH, and performance during short-term high-intensity exercise. Young healthy volunteers performed two supramaximal (125% of VO2max) exercise tests on a bicycle ergometer...

Diagnosis of coronary artery disease

International Nuclear Information System (INIS)

Pfisterer, M.; Gordon, D.; Battler, A.; Ashburn, W.; Froelicher, V.; Kantonsspital Basel

1979-01-01

In order to compare the three non-invasive exercise tests Ecg, Thallium myocardial perfusion imaging and radionuclide angiography in the diagnosis of coronary artery disease, the results of these tests in a consecutive series of 30 patients and 14 controls were analyzed. In all 88 symptom-limited exercise tests a significantly higher double product (heart rate x systolic blood pressure, mm Hg/min) was reached on a treadmill test (for Ecg and Thallium scintigraphy) as compared to the supine bicycle ergometer exercise (for radionuclide angiography): 243.1 +- 61.1 vs. 215.2 +- 46.5 x 10 2 (p [de

77 FR 60050 - Special Regulations; Areas of the National Park System, Saguaro National Park, Bicycling

Science.gov (United States)

2012-10-02

... hiking and equestrian trail that originates at the Loma Alta Trailhead and travels east through the..., including hiking, equestrian, and bicycle use. Shortly after acquiring the land, the NPS closed the route to... leadership after an adequate analysis of the benefits, impacts, and economic cost of alternative courses of...

Identifying factors affecting the safety of mid-block bicycle lanes considering mixed 2-wheeled traffic flow.

Science.gov (United States)

Bai, Lu; Chan, Ching-Yao; Liu, Pan; Xu, Chengcheng

2017-10-03

Electric bikes (e-bikes) have been one of the fastest growing trip modes in Southeast Asia over the past 2 decades. The increasing popularity of e-bikes raised some safety concerns regarding urban transport systems. The primary objective of this study was to identify whether and how the generalized linear regression model (GLM) could be used to relate cyclists' safety with various contributing factors when riding in a mid-block bike lane. The types of 2-wheeled vehicles in the study included bicycle-style electric bicycles (BSEBs), scooter-style electric bicycles (SSEBs), and regular bicycles (RBs). Traffic conflict technology was applied as a surrogate measure to evaluate the safety of 2-wheeled vehicles. The safety performance model was developed by adopting a generalized linear regression model for relating the frequency of rear-end conflicts between e-bikes and regular bikes to the operating speeds of BSEBs, SSEBs, and RBs in mid-block bike lanes. The frequency of rear-end conflicts between e-bikes and bikes increased with an increase in the operating speeds of e-bikes and the volume of e-bikes and bikes and decreased with an increase in the width of bike lanes. The large speed difference between e-bikes and bikes increased the frequency of rear-end conflicts between e-bikes and bikes in mid-block bike lanes. A 1% increase in the average operating speed of e-bikes would increase the expected number of rear-end conflicts between e-bikes and bikes by 1.48%. A 1% increase in the speed difference between e-bikes and bikes would increase the expected number of rear-end conflicts between e-bikes/bikes by 0.16%. The conflict frequency in mid-block bike lanes can be modeled using generalized linear regression models. The factors that significantly affected the frequency of rear-end conflicts included the operating speeds of e-bikes, the speed difference between e-bikes and regular bikes, the volume of e-bikes, the volume of bikes, and the width of bike lanes. The

Selective Changes in the Mechanical Capacities of Lower-Body Muscles After Cycle-Ergometer Sprint Training Against Heavy and Light Resistances.

Science.gov (United States)

García-Ramos, Amador; Torrejón, Alejandro; Pérez-Castilla, Alejandro; Morales-Artacho, Antonio J; Jaric, Slobodan

2018-03-01

To explore the feasibility of the linear force-velocity (F-V) modeling approach to detect selective changes of F-V parameters (ie, maximum force [F 0 ], maximum velocity [V 0 ], F-V slope [a], and maximum power [P 0 ]) after a sprint-training program. Twenty-seven men were randomly assigned to a heavy-load group (HLG), light-load group (LLG), or control group (CG). The training sessions (6 wk × 2 sessions/wk) comprised performing 8 maximal-effort sprints against either heavy (HLG) or light (LLG) resistances in leg cycle-ergometer exercise. Pre- and posttest consisted of the same task performed against 4 different resistances that enabled the determination of the F-V parameters through the application of the multiple-point method (4 resistances used for the F-V modeling) and the recently proposed 2-point method (only the 2 most distinctive resistances used). Both the multiple-point and the 2-point methods revealed high reliability (all coefficients of variation .80) while also being able to detect the group-specific training-related changes. Large increments of F 0 , a, and P 0 were observed in HLG compared with LLG and CG (effect size [ES] = 1.29-2.02). Moderate increments of V 0 were observed in LLG compared with HLG and CG (ES = 0.87-1.15). Short-term sprint training on a leg cycle ergometer induces specific changes in F-V parameters that can be accurately monitored by applying just 2 distinctive resistances during routine testing.

Beijing Bicycle - Stories from a Transformative Space

DEFF Research Database (Denmark)

Bagger-Petersen, Mai Corlin

2012-01-01

Ideas, words, images and stories travel from west to east – and from east to west. Stories are chosen and retold in different settings and images are reproduced and appropriated into new contexts – and in new times. Cinema, in this case the mainland Chinese, becomes both a space of production...... and a production of space that reveals how transnational and translocal mechanisms affect the cinematic language, transforming the images and stories chosen for the cinematic representation. Wang Xiaoshuai’s Beijing Bicycle (Shiqi Sui de Danche) (2001) is a result of transnational currents weaving the carpet...... relevant in a new context – that of the Chinese mainland society in the 21st century. Doreen Massey (2005: 9) defines space as “a simultaneity of stories-so-far”, a space that is constantly exploding and imploding with the influx of new and old stories. Within this theoretical framework Wang Xiaoshuai...

Comparability and repeatability of three commonly used methods for measuring endurance capacity.

Science.gov (United States)

Baxter-Gilbert, James; Mühlenhaupt, Max; Whiting, Martin J

2017-12-01

Measures of endurance (time to exhaustion) have been used to address a wide range of questions in ecomorphological and physiological research, as well as being used as a proxy for survival and fitness. Swimming, stationary (circular) track running, and treadmill running are all commonly used methods for measuring endurance. Despite the use of these methods across a broad range of taxa, how comparable these methods are to one another, and whether they are biologically relevant, is rarely examined. We used Australian water dragons (Intellagama lesueurii), a species that is morphologically adept at climbing, swimming, and running, to compare these three methods of endurance and examined if there is repeatability within and between trial methods. We found that time to exhaustion was not highly repeatable within a method, suggesting that single measures or a mean time to exhaustion across trials are not appropriate. Furthermore, we compared mean maximal endurance times among the three methods, and found that the two running methods (i.e., stationary track and treadmill) were similar, but swimming was distinctly different, resulting in lower mean maximal endurance times. Finally, an individual's endurance rank was not repeatable across methods, suggesting that the three endurance trial methods are not providing similar information about an individual's performance capacity. Overall, these results highlight the need to carefully match a measure of performance capacity with the study species and the research questions being asked so that the methods being used are behaviorally, ecologically, and physiologically relevant. © 2018 Wiley Periodicals, Inc.

Masked hypertension and cardiac remodeling in middle-aged endurance athletes

OpenAIRE

Trachsel, Lukas; Carlen, Frederic; Brugger, Nicolas Jacques; Seiler, Christian; Wilhelm, Matthias

2015-01-01

OBJECTIVES: Extensive endurance training and arterial hypertension are established risk factors for atrial fibrillation. We aimed to assess the proportion of masked hypertension in endurance athletes and the impact on cardiac remodeling, mechanics, and supraventricular tachycardias (SVT). METHODS: Male participants of a 10-mile race were recruited and included if office blood pressure was normal (

Endurance sport and "cardiac injury": a prospective study of recreational ironman athletes.

Science.gov (United States)

Leischik, Roman; Spelsberg, Norman

2014-09-03

Participation in triathlon competitions has increased in recent years. Many studies have described left or right ventricular injury in endurance athletes. The goal of this study was to examine the right and left ventricular cardiac structures and function and dynamic cardio-pulmonary performance in a large cohort of middle- and long-distance triathletes. 87 triathletes (54 male and 33 female) were examined using spiroergometry and echocardiography. The inclusion criterion was participation in at least one middle- or long distance triathlon. Male triathletes showed a maximum oxygen absorption of 58.1 ± 8.6 mL/min/kg (female triathletes 52.8 ± 5.7 mL/min/kg), maximum ergometer performance of 347.8 ± 49.9 W (female triathletes 264.5 ± 26.1 W). Left ventricular ejection fraction (EF) was normal (male triathletes EF: 61.9% ± 3%, female triathletes EF: 63.0% ± 2.7%) and systolic right ventricular area change fraction (RV AFC%) showed normal values (males RV AFC%: 33.5% ± 2.2%, females 32.2% ± 2.8%). Doppler indices of diastolic function were normal in both groups. With respect to the echocardiographic readings the left ventricular mass for males and females were 217.7 ± 41.6 g and 145.9 ± 31.3 g, respectively. The relative wall thickness for males was 0.50 ± 0.07, whereas it was 0.47 ± 0.09 for females. The probability of left ventricular mass >220 g increased with higher blood pressure during exercise (OR: 1.027, CI 1.002-1.052, p = 0.034) or with higher training volume (OR: 1.23, CI 1.04-1.47, p = 0.019). Right or left ventricular dysfunction could not be found, although the maximal participation in triathlon competitions was 29 years. A left ventricular mass >220 g is more likely to occur with higher arterial pressure during exercise and with a higher training volume.

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

Science.gov (United States)

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

2016-01-01

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

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

Directory of Open Access Journals (Sweden)

Tuomo Rankinen

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

Endurance training in mild hypertension - effects on ambulatory blood pressure and neural circulatory control.

Science.gov (United States)

Narkiewicz; Somers

1997-10-01

This review examines the effects of a single bout of exercise and of endurance training on blood pressure in patients with hypertension. Possible autonomic mechanisms that mediate these changes in blood pressure are reviewed briefly. Blood pressure rises during exercise. During the second half hour after exercise blood pressure is lower. This p;ost-exercise reduction in blood pressure is associated with a decrease in muscle sympathetic nerve activity, an increase in baroreflex gain and a reduction in the level of blood pressure (set point) at which baroreflex activation occurs. The post-exercise fall in blood pressure appears to be limited to several hours and is not likely to explain any chronic reduction in blood pressure from endurance training. Endurance training elicits modest (approximately 4-5 mmHg) reductions in blood pressure. Because of the intrinsic variability of blood pressure, the decreases in blood pressure after endurance training is evident, especially when multiple measurements of blood pressure are obtained. Studies using 24 h blood pressure measurements suggest that, although endurance training lowers daytime blood pressure, blood pressure during sleep remains unchanged. The mechanism underlying the reduction in blood pressure in endurance training is not known. Although physical fitness is known to attenuate the sympathetic response to acute exercise, whether resting sympathetic drive is decreased with endurance training remains controversial. The slowing of heart rate that accompanies endurance training is also associated with an increase in variability of heart rate. The slower heart rate, increased variability of heart rate and lower blood pressure after endurance training are accompanied by an increase in baroreflex sensitivity. Even though the antihypertensive effect of endurance training is modest, the favourable effects of physical fitness on other risk factors for cardiovascular disease make exercise training an important approach in

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

DEFF Research Database (Denmark)

Mohr, Magni; Krustrup, Peter

2016-01-01

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

Predicting bicycle helmet stage-of-change among middle school, high school, and college cyclists from demographic, cognitive, and motivational variables.

Science.gov (United States)

Weiss, Jeffrey; Okun, Morris; Quay, Nancy

2004-09-01

To apply Prochaska's Transtheoretical model of behavior change to bicycle helmet use among middle school, high school, and college students. A battery of questionnaires was administered to cyclists in the seventh and ninth grades and to college students in Phoenix, Arizona (N=797). The battery included: (1) a question to determine respondent's stage of behavior change in Prochaska's Transtheoretical model; (2) items assessing the perceived pros and cons of helmet use; (3) a bicycle safety knowledge test; and (4) demographic information. Forty-three percent of the students were in "Precontemplation," 17% were in either "Contemplation" or "Preparation," 16% were in either "Action" or "Maintenance," and 24% were in the "Relapse" stage of change. Grade, Sex, Knowledge, Pros, and Cons, and the Grade by sex and the Grade by knowledge interactions were significant predictors of helmet use stages. Compared with students in Precontemplation, students in the Contemplation stage were disproportionately younger and had higher Pro scores, lower Con scores, and more knowledge (except in the ninth grade). The Transtheoretical model of behavior change is a viable theoretical framework for designing interventions aimed at increasing bicycle helmet use in children and adolescents.

Synthesis of bicyclic alkaloids from the iridoid antirrhinoside

DEFF Research Database (Denmark)

Frederiksen, Signe Maria

The present thesis describes the isolation of the iridoid glucoside antirrhinoside from Antirrhinum majus, and the approaches made towards its transformation into analogues of biologically active compounds, with special interest in syntheses of bicyclic alkaloids.A synthetic piperidine monoterpene...... or by reduction using lithium aluminum hydride. The piperidines were subjected to hydrogenation to remove the N-benzyl group. The compounds were tested for hypoglycaemic activity by Novo Nordisk, but no activity was observed.Another approach towards a synthetic piperidine monoterpene was attempted. The strategy...... involved preparation of a diol, which through treatment of its ditosyl derivative with an amine would afford a piperidine monoterpene. Antirrhinoside was protected as its 5,6-O-monoacetonide via its 5,6:4',6'-O-diacetonide. The 5,6-O-isopropylidene-derivative was hydrogenated to give the 3,4-dihydro...

Mathematical model for studying cyclist kinematics in vehicle-bicycle frontal collisions

Science.gov (United States)

Condrea, OA; Chiru, A.; Chiriac, RL; Vlase, S.

2017-10-01

For the development of effective vehicle related safety solutions to improve cyclist protection, kinematic predictions are essential. The objective of the paper was the elaboration of a simple mathematical model for predicting cyclist kinematics, with the advantage of yielding simple results for relatively complicated impact situations. Thus, the use of elaborated math software is not required and the calculation time is shortened. The paper presents a modelling framework to determine cyclist kinematic behaviour for the situations in which a M1 category vehicle frontally hits the rear part of a bicycle. After the primary impact between the vehicle front bumper and the bicycle, the cyclist hits the vehicle’s bonnet, the windscreen or both the vehicle’s bonnet and the windscreen in short succession. The head-windshield impact is often the most severe impact, causing serious and potentially lethal injuries. The cyclist is represented by a rigid segment and the equations of motion for the cyclist after the primary impact are obtained by applying Newton’s second law of motion. The impact time for the contact between the vehicle and the cyclist is yielded afterwards by formulating and intersecting the trajectories for two points positioned on the cyclist’s head/body and the vehicle’s windscreen/bonnet while assuming that the cyclist’s equations of motion after the primary impact remain the same. Postimpact kinematics for the secondary impact are yielded by applying linear and angular momentum conservation laws.

76 FR 52046 - Final Policy Statement on the Eligibility of Pedestrian and Bicycle Improvements Under Federal...

Science.gov (United States)

2011-08-19

... important for pedestrian comfort and safety. The most successful and useful public transportation systems... could take light rail, a bus, or ride a bike.'' \\4\\ As the Secretary further described, ``livable...; (G) Eligible Activities; (H) Bicycle Sharing Programs; (I) Planning Issues; (J) Safety Concerns; (K...

Road safety and bicycle usage impacts of unbundling vehicular and cycle traffic in Dutch urban networks

NARCIS (Netherlands)

Schepers, Paul; Heinen, Eva; Methorst, Rob; Wegman, Fred

2013-01-01

Bicycle-motor vehicle crashes are concentrated along distributor roads where cyclists are exposed to greater volumes of high-speed motorists than they would experience on access roads. This study examined the road safety impact of network-level separation of vehicular and cycle traffic in Dutch

Road safety and bicycle usage impacts of unbundling vehicular and cycle traffic in Dutch urban networks.

NARCIS (Netherlands)

Schepers, P. Heinen, E. Methorst, R. & Wegman, F.

2015-01-01

Bicycle-motor vehicle crashes are concentrated along distributor roads where cyclists are exposed to greater volumes of high-speed motorists than they would experience on access roads. This study examined the road safety impact of network-level separation of vehicular and cycle traffic in Dutch

Examining the potential for modal change : motivators and barriers for bicycle commuting in Dar-es-Salaam

NARCIS (Netherlands)

Nkurunziza, A.; Zuidgeest, M.H.P.; Brussel, M.J.G.; van Maarseveen, M.F.A.M.

2012-01-01

The paper examines the effect of various motivators, barriers and policy related interventions (i.e., personal, social and physical–environmental factors) on bicycle commuting in Dares-Salaam, Tanzania. The research shows that these factors have different effects on people depending on the stage of

A Typology of Marital Quality of Enduring Marriages in Israel

Science.gov (United States)

Cohen, Orna; Geron, Yael; Farchi, Alva

2010-01-01

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

Comparative analysis of endurance of not hearing and hearing students

Directory of Open Access Journals (Sweden)

Iwańska Dagmara

2013-11-01

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

Making eco-friendly transportation safer: developing computer-based simulations to assess of the impacts of bicycle accident prevention interventions on healthcare utilization.

Science.gov (United States)

Juhra, Christian; Borycki, Elizabeth M; Kushniruk, Andre W; Anderson, Jim; Anderson, Marilyn

2011-01-01

Computer-based modeling and simulations are becoming increasingly used for applications in health and safety. In this paper we describe a multi-phase project aimed at modeling bicycle accidents in Munster, Germany. The work involved a first phase of collecting empirical data on accident rates and severity. In the second phase a computer-based simulation model of bicycle accidents was created, using data from phase one to identify relevant parameters in the model. Finally, initial results from running the model are described that will be used to inform decision making regarding safety initiatives.

Combined strength and endurance training in competitive swimmers.

Science.gov (United States)

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

2009-01-01

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

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

Directory of Open Access Journals (Sweden)

Karthikeyan Selvaganapathy

2017-12-01

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

Autonomous Soaring for Improved Endurance of a Small Uninhabited Air Vehicle

Science.gov (United States)

Allen, Michael J.

2005-01-01

A relatively unexplored method to improve the endurance of an autonomous aircraft is to use buoyant plumes of air found in the lower atmosphere called thermals or updrafts. Glider pilots and birds commonly use updrafts to improve range, endurance, or cross-country speed. This report presents a quantitative analysis of a small electric-powered uninhabited air vehicle using updrafts to extend its endurance over a target location. A three-degree-of-freedom simulation of the uninhabited air vehicle was used to determine the yearly effect of updrafts on performance. Surface radiation and rawinsonde balloon measurements taken at Desert Rock, Nevada, were used to determine updraft size, strength, spacing, shape, and maximum height for the simulation. A fixed-width spiral path was used to search for updrafts at the same time as maintaining line-of-sight to the surface target position. Power was used only when the aircraft was flying at the lower-altitude limit in search of updrafts. Results show that an uninhabited air vehicle with a nominal endurance of 2 hours can fly a maximum of 14 hours using updrafts during the summer and a maximum of 8 hours during the winter. The performance benefit and the chance of finding updrafts both depend on what time of day the uninhabited air vehicle is launched. Good endurance and probability of finding updrafts during the year was obtained when the uninhabited air vehicle was launched 30 percent into the daylight hours after sunrise each day. Yearly average endurance was found to be 8.6 hours with these launch times.

Understanding adolescents' intentions to commute by car or bicycle as adults

DEFF Research Database (Denmark)

Sigurdardottir, Sigrun Birna; Kaplan, Sigal; Møller, Mette

2013-01-01

This study focuses on the intentions of adolescents to commute by car or bicycle as adults. The behavioral model is based on intrapersonal and interpersonal constructs from the theory of planned behavior extended to include constructs from the institutional, community and policy domains. Data from...... a survey among Danish adolescents is analyzed. It is found that car use intentions are related to positive car passenger experience, general interest in cars, and car ownership norms, and are negatively related to willingness to accept car restrictions and perceived lack of behavioral control. Cycling...

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

Science.gov (United States)

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

2011-10-01

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

Age, sex and (the) race: gender and geriatrics in the ultra-endurance age.

Science.gov (United States)

Whyte, Greg

2014-01-01

Ultra-endurance challenges were once the stuff of legend isolated to the daring few who were driven to take on some of the greatest physical endurance challenges on the planet. With a growing fascination for major physical challenges during the nineteenth century, the end of the Victorian era witnessed probably the greatest ultra-endurance race of all time; Scott and Amundsen's ill-fated race to the South Pole. Ultra-endurance races continued through the twentieth century; however, these events were isolated to the elite few. In the twenty-first century, mass participation ultra-endurance races have grown in popularity. Endurance races once believed to be at the limit of human durability, i.e. marathon running, are now viewed as middle-distance races with the accolade of true endurance going to those willing to travel significantly further in a single effort or over multiple days. The recent series of papers in Extreme Physiology & Medicine highlights the burgeoning research data from mass participation ultra-endurance events. In support of a true 'mass participation' ethos Knetchtle et al. reported age-related changes in Triple and Deca Iron-ultra-triathlon with an upper age of 69 years! Unlike their shorter siblings, the ultra-endurance races appear to present larger gender differences in the region of 20% to 30% across distance and modality. It would appear that these gender differences remain for multi-day events including the 'Marathon des Sables'; however, this gap may be narrower in some events, particularly those that require less load bearing (i.e. swimming and cycling), as evidenced from the 'Ultraman Hawaii' and 'Swiss Cycling Marathon', and shorter (a term I used advisedly!) distances including the Ironman Triathlon where differences are similar to those of sprint and endurance distances i.e. c. 10%. The theme running through this series of papers is a continual rise in participation to the point where major events now require selection races to remain

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

Science.gov (United States)

Goosey-Tolfrey, V L; Vegter, R J K; Mason, B S; Paulson, T A W; Lenton, J P; van der Scheer, J W; van der Woude, L H V

2018-05-01

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 their sports wheelchair on the instrumented ergometer. Asymmetry was defined as the difference in distance and power output (PO) between left and right sides when the best side reached 28 m. Propulsion techniques were quantified based on torque and velocity data. HP players covered an average 3 m further than the LP players (P = .002) and achieved faster sprint times than LP players (6.95 ± 0.89 vs 8.03 ± 0.68 seconds, P = .005) and at the time the best player finished (5.96 seconds). Higher peak POs (667 ± 108 vs 357 ± 78 W, P = .0001) and greater peak speeds that were also evident were for HP players (4.80 ± 0.71 vs 4.09 ± 0.45 m/s, P = .011). Greater asymmetries were found in HP players for distance (1.86 ± 1.43 vs 0.70 ± 0.65 m, P = .016), absolute peak PO (P = .049), and speed (0.35 ± 0.25 vs 0.11 ± 0.10 m/s, P = .009). Although HP players had faster sprint times over 28 m (achieved by a higher PO), high standard deviations show the heterogeneity within the two groups (eg, some LP players were better than HP players). Quantification of asymmetries is important not only for classifiers but also for sports practitioners wishing to improve performance as they could be addressed through training and/or wheelchair configuration. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Plutonium in an enduring fuel cycle

International Nuclear Information System (INIS)

Pillay, K.K.S.

1998-05-01

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

[Association between speed and endurance performance with sleep duration in children and adolescents].

Science.gov (United States)

Chen, T Q; Dong, B; Zhang, W J; Gao, D S; Dong, Y H; Ma, J; Ma, Y H

2018-06-18

To analyze the association between sleep duration and athletic performance, and provide scientific basis to improve the 50 m and endurance performance in children and adolescents. All the 119 462 subjects aged 9-15 years in both genders were sampled from 2014 National Physical Fitness and Health Surveillance by using stratified random cluster sampling method, to measure the height, weight, 50 meters and endurance performance and investigate sleep duration with questionnaire. Their body mass indexes (BMI) were calculated and the students' 50 m, endurance run scores and sleep durations were assessed. Binary Logistic regression was used to analyze the difference between the different sleep groups, and multifactor Logistic regression was used to analyze the relationship between the sleep condition and athletic performance. The prevalence of insufficient sleep was 94.67% in the total subjects, the prevalence was higher among the girls (95.26%)than the boys (94.09%, χ 2 =80.99, Pchildren with sufficient sleep had better performance in 50 m and endurance run scores( χ 2 50 m =10.10, P 50 m ＜0.01; χ 2 endurance run =21.76, Pchildren with adequate sleep showed better results(OR 50 m =1.14, 95%CI 50 m =1.05-1.23, P 50 m endurance run =1.21, 95%CI endurance run =1.11-1.31, P endurance run endurance run scores in the boys with adequate sleep were higher (Pendurance run excellent rates in the girls of different sleep conditions. The excellent rates of 50 m and endurance run in the urban children and the endurance rate in the rural children and adolescents with adequate sleep were higher than those with insufficient sleep (Psleep groups in rural areas. The 50 m and endurance run excellent rates of the children and adolescents with adequate sleep in each grade were higher than those of the children in the same grade with insufficient sleep (P primary students' endurance performance Children and adolescents with normal BMI and overweight who slept well had better

Endocrine Changes In Egyptian Female Olympic Runners

International Nuclear Information System (INIS)

Bayad, M.A.; Fahmy, N.M.

2002-01-01

Circulating levels of testosterone (T), free testosterone (FT), and rostenedione (A) estradial 17-B (E 2 ), dehydroepiandrosterone sulfate (DHEA-S), sex hormone binding globulin (SHBG), luteninzing hormone (LH) and cortisol (C) were estimated by RIA proccdures in the serum of two groups of athletic female runners. An eumenorrheic group (n=10), and an oligomenorrheic group (n=10), and in a healthy regularly menstruating group as control(n=20). The athletes were subjected to a stadardized Ergometer testing aiming at achieving maximal O 2 consumption. Blood samples were with drawn at rest and immediately after exercise in the eumenorrheic and oligomenorrheic groups. Samples from eumenorrheic athletes and control group were at midfollicular phase of the cycle; and randomly in the oligomenorrheicat athlets. Results revealed a state of hypercortisolism in resting eumenorrheic athletes in comparison with control, whereas the oligomenorrheic athletes showed a state of hypercortisolism, hyperandrogenism and hyperestrogenism. The estimated perameters showed remrakable significant increase after the bicycle Ergometer testing, with the exception of SHBG and DHEA-S in the athletic groups

Altitude training for elite endurance performance: a 2012 update.

Science.gov (United States)

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

2012-01-01

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

Characteristics of bicyclic sesquiterpanes in crude oils and petroleum products.

Science.gov (United States)

Yang, Chun; Wang, Zhendi; Hollebone, Bruce P; Brown, Carl E; Landriault, Mike

2009-05-15

This study presents a quantitative gas chromatography-mass spectrometry analysis of bicyclic sesquiterpanes (BSs) in numerous crude oils and refined petroleum products including light and mid-range distillate fuels, residual fuels, and lubricating oils collected from various sources. Ten commonly recognized bicyclic sesquiterpanes were determined in all the studied crude oils and diesel range fuels with principal dominance of BS3 (C(15)H(28)), BS5 (C(15)H(28)) and BS10 (C(16)H(30)), while they were generally not detected or in trace in light fuel oils like gasoline and kerosene and most lubricating oils. Laboratory distillation of crude oils demonstrated that sesquiterpanes were highly enriched in the medium distillation fractions of approximately 180 to 481 degrees C and were generally absent or very low in the light distillation fraction (boiling point to approximately 180 degrees C) and the heavy residual fraction (>481 degrees C). The effect of evaporative weathering on a series of diagnostic ratios of sesquiterpanes, n-alkanes, and biomarkers was evaluated with two suites of weathered oil samples. The change of abundance of sesquiterpanes was used to determine the extent of weathering of artificially evaporated crude oils and diesel. In addition to the pentacyclic biomarker C(29) and C(30) alphabeta-hopane, C(15) and C(16) sesquiterpanes might be alternative internal marker compounds to provide a direct way to estimate the depletion of oils, particularly diesels, in oil spill investigations. These findings may offer potential applications for both oil identification and oil-source correlation in cases where the tri- to pentacyclic biomarkers are absent due to refining or environmental weathering of oils.

201Tl in myocardial diagnosis: studies on the influence of dipyridamole, dobutamine ergometer exercise and background subtraction on the 201Tl myocadial scintiscam

International Nuclear Information System (INIS)

Seiderer, M.

1979-01-01

Changes in 201 Tl myocardial scintiscans upon administration of dipyridamole or dobutamine and upon ergometer exercise relative to scintiscans at rest were investigated as well as the influence of myocardial background subtraction on scintiscan quality and information. A total of 90 201 Tl examinations were carried out in 59 patients. 18 patients had no myocardial disease, 30 patients had a coronary disease, 5 patients suffered from cardiomyopathy and 6 from left ventricular hypertrophy. The findings are discussed in detail. (orig.) [de

Speed endurance training is a powerful stimulus for physiological adaptations and performance improvements of athletes

DEFF Research Database (Denmark)

Iaia, F. M.; Bangsbo, Jens

2010-01-01

the oxidative capacity and improve intense short-duration/repeated high-intensity exercise performance lasting 30 s to 4 min, as it occurs in a number of sports. When combined with a basic volume of training including some aerobic high-intensity sessions, speed endurance training is also useful in enhancing......The present article reviews the physiological and performance effects of speed endurance training consisting of exercise bouts at near maximal intensities in already trained subjects. Despite a reduction in training volume, speed endurance training of endurance-trained athletes can maintain...... performance during longer events, e.g. 40 K cycling and 10 K running. Athletes in team sports involving intense exercise actions and endurance aspects can also benefit from performing speed endurance training. These improvements don't appear to depend on changes in maximum oxygen uptake (VO2max), muscle...

Which environmental factors most strongly influence a street's appeal for bicycle transport among adults? A conjoint study using manipulated photographs.

Science.gov (United States)

Mertens, Lieze; Van Dyck, Delfien; Ghekiere, Ariane; De Bourdeaudhuij, Ilse; Deforche, Benedicte; Van de Weghe, Nico; Van Cauwenberg, Jelle

2016-09-01

Micro-environmental factors (specific features within a streetscape), instead of macro-environmental factors (urban planning features), are more feasible to modify in existing neighborhoods and thus more practical to target for environmental interventions. Because it is often not possible to change the whole micro-environment at once, the current study aims to determine which micro-environmental factors should get the priority to target in physical environmental interventions increasing bicycle transport. Additionally, interaction effects among micro-environmental factors on the street's appeal for bicycle transport will be determined. In total, 1950 middle-aged adults completed a web-based questionnaire consisting of a set of 12 randomly assigned choice tasks with manipulated photographs. Seven micro-environmental factors (type of cycle path, speed limit, speed bump, vegetation, evenness of the cycle path surface, general upkeep and traffic density) were manipulated in each photograph. Conjoint analysis was used to analyze the data. Providing streets with a cycle path separated from motorized traffic seems to be the best strategy to increase the street's appeal for adults' bicycle transport. If this adjustment is not practically feasible, micro-environmental factors related to safety (i.e. speed limit, traffic density) may be more effective in promoting bicycle transport than micro-environmental factors related to comfort (i.e. evenness of the cycle path surface) or aesthetic (i.e. vegetation, general upkeep). On the other hand, when a more separated cycle path is already provided, micro-environmental factors related to comfort or aesthetic appeared to become more prominent. Findings obtained from this research could provide advice to physical environmental interventions about which environmental factors should get priority to modify in different environmental situations. The study was approved by the Ethics Committee of the Ghent University Hospital. B

A proper choice of route significantly reduces air pollution exposure--a study on bicycle and bus trips in urban streets.

Science.gov (United States)

Hertel, Ole; Hvidberg, Martin; Ketzel, Matthias; Storm, Lars; Stausgaard, Lizzi

2008-01-15

A proper selection of route through the urban area may significantly reduce the air pollution exposure. This is the main conclusion from the presented study. Air pollution exposure is determined for two selected cohorts along the route going from home to working place, and back from working place to home. Exposure is determined with a street pollution model for three scenarios: bicycling along the shortest possible route, bicycling along the low exposure route along less trafficked streets, and finally taking the shortest trip using public transport. Furthermore, calculations are performed for the cases the trip takes place inside as well as outside the traffic rush hours. The results show that the accumulated air pollution exposure for the low exposure route is between 10% and 30% lower for the primary pollutants (NO(x) and CO). However, the difference is insignificant and in some cases even negative for the secondary pollutants (NO(2) and PM(10)/PM(2.5)). Considering only the contribution from traffic in the travelled streets, the accumulated air pollution exposure is between 54% and 67% lower for the low exposure route. The bus is generally following highly trafficked streets, and the accumulated exposure along the bus route is therefore between 79% and 115% higher than the high exposure bicycle route (the short bicycle route). Travelling outside the rush hour time periods reduces the accumulated exposure between 10% and 30% for the primary pollutants, and between 5% and 20% for the secondary pollutants. The study indicates that a web based route planner for selecting the low exposure route through the city might be a good service for the public. In addition the public may be advised to travel outside rush hour time periods.

Effects of moderate and heavy endurance exercise on nocturnal HRV.

Science.gov (United States)

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

2010-06-01

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

Severe street and mountain bicycling injuries in adults: a comparison of the incidence, risk factors and injury patterns over 14 years.

Science.gov (United States)

Roberts, Derek J; Ouellet, Jean-Francois; Sutherland, Francis R; Kirkpatrick, Andrew W; Lall, Rohan N; Ball, Chad G

2013-06-01

Street and mountain bicycling are popular recreational activities and prevalent modes of transportation with the potential for severe injury. The purpose of this investigation was to compare the incidence, risk factors and injury patterns among adults with severe street versus mountain bicycling injuries. We conducted a retrospective cohort study using the Southern Alberta Trauma Database of all adults who were severely injured (injury severity score [ISS] ≥ 12) while street or mountain bicycling between Apr. 1, 1995, and Mar. 31, 2009. Among 11 772 severely injured patients, 258 (2.2%) were injured (mean ISS 17, hospital stay 6 d, mortality 7%) while street (n = 209) or mountain bicycling (n = 49). Street cyclists were often injured after being struck by a motor vehicle, whereas mountain bikers were frequently injured after faulty jump attempts, bike tricks and falls (cliffs, roadsides, embankments). Mountain cyclists were admitted more often on weekends than weekdays (61.2% v. 45.0%, p = 0.040). Injury patterns were similar for both cohorts (all p > 0.05), with trauma to the head (67.4%), extremities (38.4%), chest (34.1%), face (26.0%) and abdomen (10.1%) being common. Spinal injuries, however, were more frequent among mountain cyclists (65.3% v. 41.1%, p = 0.003). Surgical intervention was required in 33.3% of patients (9.7% open reduction internal fixation, 7.8% spinal fixation, 7.0% craniotomy, 5.8% facial repair and 2.7% laparotomy). With the exception of spine injuries, severely injured cyclists display similar patterns of injury and comparable outcomes, regardless of style (street v. mountain). Helmets and thoracic protection should be advocated for injury prevention.

Understanding and measuring bicycling behavior : a focus on travel time and route choice, final report, December 2008.

Science.gov (United States)

2008-12-01

With rates of obesity, heart disease, and related health problems increasing in the U.S., many policy makers are looking for ways to increase : physical activity in everyday life. Using a bicycle instead of a motor vehicle for a portion of everyday t...

Applying the health action process approach to bicycle helmet use and evaluating a social marketing campaign.

Science.gov (United States)

Karl, Florian M; Smith, Jennifer; Piedt, Shannon; Turcotte, Kate; Pike, Ian

2017-08-05

Bicycle injuries are of concern in Canada. Since helmet use was mandated in 1996 in the province of British Columbia, Canada, use has increased and head injuries have decreased. Despite the law, many cyclists do not wear a helmet. Health action process approach (HAPA) model explains intention and behaviour with self-efficacy, risk perception, outcome expectancies and planning constructs. The present study examines the impact of a social marketing campaign on HAPA constructs in the context of bicycle helmet use. A questionnaire was administered to identify factors determining helmet use. Intention to obey the law, and perceived risk of being caught if not obeying the law were included as additional constructs. Path analysis was used to extract the strongest influences on intention and behaviour. The social marketing campaign was evaluated through t-test comparisons after propensity score matching and generalised linear modelling (GLM) were applied to adjust for the same covariates. 400 cyclists aged 25-54 years completed the questionnaire. Self-efficacy and Intention were most predictive of intention to wear a helmet, which, moderated by planning, strongly predicted behaviour. Perceived risk and outcome expectancies had no significant impact on intention. GLM showed that exposure to the campaign was significantly associated with higher values in self-efficacy, intention and bicycle helmet use. Self-efficacy and planning are important points of action for promoting helmet use. Social marketing campaigns that remind people of appropriate preventive action have an impact on behaviour. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Methodological proposal for the implementation of shared bicycle applied to the Brazilian context

OpenAIRE

BARBOSA, PHILIPPE; Modesto de Sousa, Adriana; Azevedo Oliveira, Rodrigo; ESPANA, JUAN

2016-01-01

[EN] The main objective of this study is to analyze the bicycle rental system in the Federal District "Bike Brasilia". It aims to identify guidelines that supported the application process and consensus, disagreements and guidelines established by the Institute for Policies and Development in Transportation - ITDP and relate those listed by Zhang regarding rented bikes systems. This is an exploratory study based on the strategy of document analysis and its secondary sources: institutional doc...

Understanding the Magic of the Bicycle; Basic scientific explanations to the two-wheeler's mysterious and fascinating behavior

Science.gov (United States)

Connolly, Joseph W.

The bicycle is a common, yet unique mechanical contraption in our world. In spite of this, the bike's physical and mechanical principles are understood by a select few. You do not have to be a genius to join this small group of people who understand the physics of cycling. This is your guide to fundamental principles (such as Newton's laws) and the book provides intuitive, basic explanations for the bicycle's behaviour. Each concept is introduced and illustrated with simple, everyday examples. Although cycling is viewed by most as a fun activity, and almost everyone acquires the basic skills at a young age, few understand the laws of nature that give magic to the ride. This is a closer look at some of these fun, exhilarating, and magical aspects of cycling. In the reading, you will also understand other physical principles such as motion, force, energy, power, heat, and temperature.

Galectin-3 increase in endurance athletes

NARCIS (Netherlands)

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

2014-01-01

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

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

Science.gov (United States)

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

2017-10-01

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

Synthesis and biological evaluation of novel dioxa-bicycle C-aryl glucosides as SGLT2 inhibitors.

Science.gov (United States)

Yan, Qi; Ding, Ning; Li, Yingxia

2016-02-08

A series of novel C-aryl glucosides containing dioxa-bicycle were synthesized and evaluated for inhibition activity against hSGLT2. Among the compounds tested, compound 6a showed moderate SGLT2 inhibition activities at 700 nM. The results could benefit the discovery of new SGLT2 inhibitors. Copyright © 2015 Elsevier Ltd. All rights reserved.

New pentose dimers with bicyclic moieties from pretreated biomass

DEFF Research Database (Denmark)

Rasmussen, H.; Sørensen, Henrik Rokkjær; Tanner, David Ackland

2017-01-01

In lignocellulosic biorefinery processes involving enzyme catalysed reactions it is a challenge that enzyme inhibiting compounds are generated and liberated during pretreatment of the biomass. In this study the contribution to cellulase inhibition from xylooligosaccharides and newly discovered...... oligophenolic compounds from pilot scale pretreated wheat straw was assessed at two different pretreatment severities. An increase in severity of the pretreatment led to more oligophenol compounds and in turn the total overall cellulase inhibition increased. When the xylooligosaccharides were enzymatically...... degraded prior to cellulose hydrolysis, a relief in cellulase inhibition was observed, but some inhibition remained, suggesting that other components also played a role in inhibition. We propose that these components include dipentoses with bicyclic moieties and feruloylated tripentoses, because LC...

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

NARCIS (Netherlands)

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

1994-01-01

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

Pedalling rate affects endurance performance during high-intensity cycling

DEFF Research Database (Denmark)

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

2004-01-01

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

Endurance training enhances BDNF release from the human brain

DEFF Research Database (Denmark)

Seifert, Thomas; Brassard, Patrice; Wissenberg, Mads

2010-01-01

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

[Prevalence of helmet use in children and adolescents in Germany and preventable bicycle-related head injuries].

Science.gov (United States)

Gutsche, J; Hintzpeter, B; Neuhauser, H; Schlaud, M

2011-08-01

Head injuries are the main cause of death in bicycle-related accidents among children and adolescents. According to a Cochrane Review, the risk of head injury (OR 0.31; 95% CI 0.26-0.37) or brain injury (OR 0.31; 95% CI 0.23-0.42) decreases by 69% if a helmet is worn. This study presents the prevalence of helmet use in cycling children and adolescents in Germany and the proportion of head injuries that could be prevented by wearing helmets. The potential effects of increased helmet wearing rates on the population attributable risk percentage for head injuries (PAR%) are demonstrated. The prevalence of helmet use in children aged 3-17 years was analysed using data from the German Health Interview and Examination Survey for Children and Adolescents (KiGGS). The percentage of head injuries preventable by helmet use in this group is estimated by calculating PAR%. Prevalence rates of helmet use and odds ratios from a Cochrane Review about the effectiveness of bicycle helmets for the prevention of head injuries were used for analysis. The potential effect of increased helmet use is shown in 3 scenarios by means of differences of PAR% values in the most relevant age groups. The older the children, the less likely they are to wear a helmet: 89.5% (95% CI 88.0%-90.8%) of the 3- to 6-year-old children wear a helmet when cycling but only 11.0% (95% CI 9.3%-12.9%) of 14- to 17-year-old adolescents do. In the youngest group (3-6 years) 19% of bicycle-related head injuries are attributable to the non-use of helmets, but this proportion rises to 67% in the oldest group (14-17 years). The PAR% of head injuries associated with not wearing a helmet may be reduced by more than a third by increasing the helmet wearing rate to 67% (2 out of 3) among adolescents, and may be reduced to half if 75% of adolescents wore a helmet. Particularly older children and adolescents hardly use bicycle helmets, hence the rate of preventable head injury is high. Efforts towards increasing helmet use

Endurance Sport and “Cardiac Injury”: A Prospective Study of Recreational Ironman Athletes

Science.gov (United States)

Leischik, Roman; Spelsberg, Norman

2014-01-01

Background: Participation in triathlon competitions has increased in recent years. Many studies have described left or right ventricular injury in endurance athletes. The goal of this study was to examine the right and left ventricular cardiac structures and function and dynamic cardio-pulmonary performance in a large cohort of middle- and long-distance triathletes. Methods: 87 triathletes (54 male and 33 female) were examined using spiroergometry and echocardiography. The inclusion criterion was participation in at least one middle- or long distance triathlon. Results: Male triathletes showed a maximum oxygen absorption of 58.1 ± 8.6 mL/min/kg (female triathletes 52.8 ± 5.7 mL/min/kg), maximum ergometer performance of 347.8 ± 49.9 W (female triathletes 264.5 ± 26.1 W). Left ventricular ejection fraction (EF) was normal (male triathletes EF: 61.9% ± 3%, female triathletes EF: 63.0% ± 2.7%) and systolic right ventricular area change fraction (RV AFC%) showed normal values (males RV AFC%: 33.5% ± 2.2%, females 32.2% ± 2.8%). Doppler indices of diastolic function were normal in both groups. With respect to the echocardiographic readings the left ventricular mass for males and females were 217.7 ± 41.6 g and 145.9 ± 31.3 g, respectively. The relative wall thickness for males was 0.50 ± 0.07, whereas it was 0.47 ± 0.09 for females. The probability of left ventricular mass >220 g increased with higher blood pressure during exercise (OR: 1.027, CI 1.002–1.052, p = 0.034) or with higher training volume (OR: 1.23, CI 1.04–1.47, p = 0.019). Conclusions: Right or left ventricular dysfunction could not be found, although the maximal participation in triathlon competitions was 29 years. A left ventricular mass >220 g is more likely to occur with higher arterial pressure during exercise and with a higher training volume. PMID:25192145

Endurance Sport and “Cardiac Injury”: A Prospective Study of Recreational Ironman Athletes

Directory of Open Access Journals (Sweden)

Roman Leischik

2014-09-01

Full Text Available Background: Participation in triathlon competitions has increased in recent years. Many studies have described left or right ventricular injury in endurance athletes. The goal of this study was to examine the right and left ventricular cardiac structures and function and dynamic cardio-pulmonary performance in a large cohort of middle- and long-distance triathletes. Methods: 87 triathletes (54 male and 33 female were examined using spiroergometry and echocardiography. The inclusion criterion was participation in at least one middle- or long distance triathlon. Results: Male triathletes showed a maximum oxygen absorption of 58.1 ± 8.6 mL/min/kg (female triathletes 52.8 ± 5.7 mL/min/kg, maximum ergometer performance of 347.8 ± 49.9 W (female triathletes 264.5 ± 26.1 W. Left ventricular ejection fraction (EF was normal (male triathletes EF: 61.9% ± 3%, female triathletes EF: 63.0% ± 2.7% and systolic right ventricular area change fraction (RV AFC% showed normal values (males RV AFC%: 33.5% ± 2.2%, females 32.2% ± 2.8%. Doppler indices of diastolic function were normal in both groups. With respect to the echocardiographic readings the left ventricular mass for males and females were 217.7 ± 41.6 g and 145.9 ± 31.3 g, respectively. The relative wall thickness for males was 0.50 ± 0.07, whereas it was 0.47 ± 0.09 for females. The probability of left ventricular mass >220 g increased with higher blood pressure during exercise (OR: 1.027, CI 1.002–1.052, p = 0.034 or with higher training volume (OR: 1.23, CI 1.04–1.47, p = 0.019. Conclusions: Right or left ventricular dysfunction could not be found, although the maximal participation in triathlon competitions was 29 years. A left ventricular mass >220 g is more likely to occur with higher arterial pressure during exercise and with a higher training volume.

Arctigenin Efficiently Enhanced Sedentary Mice Treadmill Endurance

Science.gov (United States)

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

2011-01-01

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

Arctigenin efficiently enhanced sedentary mice treadmill endurance.

Directory of Open Access Journals (Sweden)

Xuan Tang

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

North Central Texas Council of Governments peer exchange on bicycle and pedestrian count programs : a TPCB peer exchange

Science.gov (United States)

2013-05-29

This report highlights key recommendations and best practices identified at the peer exchange on bicycle and pedestrian count programs, held on May 29 and May 30, 2013 in Arlington, Texas. The North Central Texas Council of Governments (NCTCOG) reque...

Synthesis of fused bicyclic piperidines: potential bioactive templates for medicinal chemistry.

Science.gov (United States)

Zhou, Jinglan; Campbell-Conroy, Erica L; Silina, Alina; Uy, Johnny; Pierre, Fabrice; Hurley, Dennis J; Hilgraf, Nicole; Frieman, Bryan A; DeNinno, Michael P

2015-01-02

An array of six pyridyl-substituted fused bicyclic piperidines was prepared as novel cores for medicinal chemistry. For maximum diversity, the size of the fused ring varied from three to six atoms and contained up to two oxygen atoms. The pyridine ring was incorporated to improve physicochemical properties and to challenge the robustness of the chemistry. The presence of the pyridine did interfere with our initial approaches to these molecules, and in several instances, a blocking strategy had to be employed. These new scaffolds possess high sp3 character and may prove useful in multiple medicinal chemistry applications.

Effects of resistance training on endurance capacity and muscle fiber composition in young top-level cyclists

DEFF Research Database (Denmark)

Aagaard, P; Andersen, J L; Bennekou, M

2011-01-01

Equivocal findings exist on the effect of concurrent strength (S) and endurance (E) training on endurance performance and muscle morphology. Further, the influence of concurrent SE training on muscle fiber-type composition, vascularization and endurance capacity remains unknown in top......-level endurance athletes. The present study examined the effect of 16 weeks of concurrent SE training on maximal muscle strength (MVC), contractile rate of force development (RFD), muscle fiber morphology and composition, capillarization, aerobic power (VO(2max) ), cycling economy (CE) and long....../short-term endurance capacity in young elite competitive cyclists (n=14). MVC and RFD increased 12-20% with SE (P...

Effects of resistance training on endurance capacity and muscle fiber composition in young top-level cyclists

DEFF Research Database (Denmark)

Aagaard, P; Andersen, J L; Bennekou, M

2011-01-01

Equivocal findings exist on the effect of concurrent strength (S) and endurance (E) training on endurance performance and muscle morphology. Further, the influence of concurrent SE training on muscle fiber-type composition, vascularization and endurance capacity remains unknown in top......-level endurance athletes. The present study examined the effect of 16 weeks of concurrent SE training on maximal muscle strength (MVC), contractile rate of force development (RFD), muscle fiber morphology and composition, capillarization, aerobic power (VO2max), cycling economy (CE) and long/short-term endurance...... capacity in young elite competitive cyclists (n=14). MVC and RFD increased 12-20% with SE (P...

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

Directory of Open Access Journals (Sweden)

Marco Carlos Uchida

2008-02-01

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

Adapted low intensity ergometer aerobic training for early and severely impaired stroke survivors: a pilot randomized controlled trial to explore its feasibility and efficacy.

Science.gov (United States)

Wang, Zun; Wang, Lei; Fan, Hongjuan; Jiang, Wenjun; Wang, Sheng; Gu, Zhaohua; Wang, Tong

2014-09-01

[Purpose] To evaluate the feasibility and efficacy of adapted low intensity ergometer aerobic training for early and severely impaired stroke survivors. [Subjects] The subjects were forty-eight early stroke survivors. [Methods] Eligible subjects were recruited and randomly assigned to an experimental group and a control group. Both groups participated in comprehensive rehabilitation training. Low intensity aerobic training was only performed by the experimental group. Outcome measures were the Fugl-Meyer motor score, Barthel index, exercise test time, peak heart rate, plasma glucose level and serum lipid profiles. [Results] Patients in the experimental group finished 88.6% of the total aerobic training sessions prescribed. In compliant participants (adherence≥80%), aerobic training significantly improved the Barthel index (from 40.1±21.1 to 79.2±14.2), Fugl-Meyer motor score (from 26.4±19.4 to 45.4±12.7), exercise test time (from 12.2±3.62 min to 13.9±3.6 min), 2-hour glucose level (from 9.22±1.16 mmol/L to 7.21±1.36 mmol/L) and homeostasis model of assessment for insulin resistence index (from 1.72±1.01 to 1.28±0.88). [Conclusion] Preliminary findings suggest that early and severely impaired stroke patients may benefit from low intensity ergometer aerobic training.

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

International Nuclear Information System (INIS)

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

1998-06-01

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

An exploratory study into the effect of exhausting bicycle exercise on endocrine and immune responses in post-menopausal women : Relationships between vigour and plasma cortisol concentrations and lymphocyte proliferation following exercise

NARCIS (Netherlands)

van der Pompe, G; Bernards, N; Kavelaars, A; Heijnen, C

It is well-established that bicycle exercise alters the endocrine and immune responses in men, but little information is available for women, especially middle-aged, post-menopausal women. The purpose of our study was to document the endocrine and immune reactivity to exhausting bicycle exercise in

Intelligence Community Programs, Management, and Enduring Issues

Science.gov (United States)

2016-11-08

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

'Endurance' Courtesy of Mars Express

Science.gov (United States)

2004-01-01

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

77 FR 12761 - Special Regulations; Areas of the National Park System, Saguaro National Park, Bicycle Route

Science.gov (United States)

2012-03-02

..., preserve, and interpret the monument's resources, and to provide for education and benefit to the public... worldwide as an icon of the American Southwest. The Hope Camp Trail is a 2.8 mile long hiking and equestrian... the route to be used for recreational purposes, including hiking, equestrian and bicycle use. Shortly...

Effect of salbutamol on neuromuscular function in endurance athletes.

Science.gov (United States)

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

2013-10-01

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