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1.
The purpose of this study was to compare the maximal exercise performance during cycle ergometry of 34 men and 47 women. External peak power output (OPP) and optimized pedalling rate (ORPM) were calculated from data gathered during an optimization procedure performed on a friction braked cycle ergometer. In addition, lean leg volume (LLV) and lean upper leg volume (LULV) were determined using an anthropometric technique. Both OPP and ORPM were greater in men than in women (1007 +/- 135 vs 673 +/- 109 W and 119.5 +/- 7.0 vs 104.5 +/- 8.4 rev min-1, respectively; P less than 0.001). The LLV and LULV were also greater in men than in women (7.41 +/- 0.82 vs 5.19 +/- 0.85 l and 4.96 +/- 0.63 vs 3.35 +/- 0.62 l, respectively; P less than 0.001). The ratio standards OPP/LLV and OPP/LULV did not differ significantly between men and women (136.3 +/- 14.7 vs 131.0 +/- 20.6 W l-1 and 204.4 +/- 27.1 vs 204.4 +/- 37.0 W l-1, respectively; P greater than 0.05). Peak power output was related to each of the anthropometric indices in both men and women (LLV:r = 0.614 and 0.527, P less than 0.001; LULV:r = 0.489 and 0.396, P less than 0.01). Analysis of covariance revealed no significant differences between the groups in the variance about regression and the regression coefficients (P greater than 0.05), but the elevation of the regression lines did differ (P less than 0.001). The results suggest that there are differences between maximal exercise performance in men and women that are independent of estimated lean leg volume. They also demonstrate that, in this case, consideration of ratio standards is misleading and that a comparison of regression standards is more appropriate.  相似文献   

2.
The aim of the study was to assess the relationship between performance-based and laboratory tests for muscular strength and power assessment in older women. Thirty-two women aged 68.8 +/- 2.8 years were recruited. All participants were asessed for: (a) two performance-based tests--the box-stepping test (mean 296 +/- 51 J) and two-revolution maximum test (mean 7.1 +/- 2 kg) performed while pedalling on a cycle ergometer; and (b) muscular function tests--maximal instantaneous peak power jumping on a force platform (mean 1528 +/- 279 W); maximal voluntary contraction (MVC) during knee extension (mean 601 +/- 571 N) and leg press (mean 626 +/- 126 N), and leg press power (mean 483 +/- 98 W) on a dynamometer. Using univariate analysis, performance-based tests were compared with laboratory muscle strength and power measurements. Muscle power correlated most strongly with the performance-based tests for both jumping and leg press power (r-values between 0.67 and 0.75; P < 0.01). The correlation with muscle strength measures ranged between 0.48 and 0.61 (P < 0.01). The proposed tests may have particular relevance in geriatric and rehabilitation environments as they represent an easy, practical, and inexpensive alternative for the assessment of muscular strength and power.  相似文献   

3.
The aim of this study was to assess the relationship between several commonly used aerobic and anaerobic cycle ergometer tests and performance during a treadmill cycling hill climb. Eight competitive cyclists (age 27+/-7 years; body mass 73.2+/-5.2 kg; height 177+/-6 cm; mean +/- s) completed six tests in random order: a lactate minimum test; a Wingate anaerobic power test; and two 6-km climbs at 6% and two 1-km climbs at 12% gradient performed on a motorized treadmill. The mean times and power outputs for the 6-km and 1-km climbs were 16:30+/-1:08 min: s and 330+/-17.8 W, and 4:19+/-0:27 min: s and 411+/-24.4 W, respectively. The best individual predictor of 6-km and 1-km performance times was the time for the corresponding climb at the other distance (r = 0.97). The next strongest predictor of both hill climb performances was the average power produced during the Wingate test divided by body mass. Stepwise regression analysis showed that the two variables contributing most to the prediction equation for both climbs were the Wingate average power per unit of body mass and maximal aerobic power divided by total mass (rider + bike), which together accounted for 92 and 96% of the variability in the 6-km and 1-km climbs. In conclusion, among competitive cyclists, the Wingate average power per unit of body mass was the best single predictor of simulated cycling hill climb performance at the distance and gradient used.  相似文献   

4.
A 30-s 'all-out' power protocol was studied in four groups of racing cyclists including internationals (n = 8), Category 1 (n = 10), Category 2 (n = 15) and Category 3 (n = 11). Following warm-up each subject completed five trials interspersed by 3 min of low intensity exercise on an ergowheel racing cycle ergometry system at a power output of 15 W kg-1 body weight, generated at 130 rev min-1. Temporal indices of performance included delay time (DT) to achieve the power criterion, total time (TT) of the maintenance of the power criterion and the ratio of TT/DT. 'Explosive' leg strength was assessed from a vertical jump. The results indicated that international and Category 1 cyclists had lower DT (2.2 +/- 0.1 s and 2.1 +/- 0.0 s, respectively; P less than 0.05), higher TT (28.1 +/- 0.7 s and 27.0 +/- 0.7 s, respectively; P less than 0.05) and elevated TT/DT (12.8 and 12.9, respectively; P less than 0.01). 'Explosive' leg strength was also higher (P less than 0.05) in the internationals than in the other groups of cyclists. The protocol provides a sport-related method for the assessment of short term endurance performance ability in racing cyclists which may be of value in identifying the anaerobic capability of individual cyclists.  相似文献   

5.
Bicarbonate ingestion: effects of dosage on 60 s cycle ergometry.   总被引：3，自引：0，他引：3  
Nine healthy male subjects who were all participating in athletic events volunteered to take part in this study, the aim of which was to determine whether there are specific dosages of sodium bicarbonate (HCO3-) that are useful as an ergogenic aid as far as anaerobic performance times are concerned. A control, placebo (CaCO3 500 mg kg-1) and five dosages of bicarbonate (100, 200, 300, 400 and 500 mg kg-1) were used. The anaerobic test consisted of pedalling a Repco Exertech cycle ergometer for 1 min during which total work (kJ) and peak power (W) were measured. The subjects completed more work in the 200 (P < 0.05), 300, 400 and 500 mg kg-1 (P < 0.005) trials with most work being undertaken in the 300 mg kg-1 trial (41.9 kJ min-1). Peak power was not significantly different from the control until the 300 mg kg-1 dose, and there were no further changes from this with increasing doses of HCO3-. The highest level of peak power achieved was 1295 +/- 72.8 W at the 300 mg kg-1 dosage. Blood pH indicated that after ingestion of all but the 100 mg kg-1 dose, a state of alkalosis was achieved (P < 0.005), and this was also indicated by changes in base excess. Bicarbonate levels increased post-ingestion in all but the 100 mg kg-1 dose, with these changes reflecting the changes that occurred in the work output. Blood lactate (BLa) levels increased post-exercise (P < 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

6.
The aim of this study was to compare optimization and correction procedures for the determination of peak power output during friction-loaded cycle ergometry. Ten male and 10 female sports students each performed five 10-s sprints from a stationary start on a Monark 864 basket-loaded ergometer. Resistive loads of 5.0, 6.5, 8.0, 9.5, and 11.0% body weight were administered in a counterbalanced order, with a recovery period of 10 min between sprints. Peak power was greater and occurred earlier, with less work having been done before the attainment of peak power, when the data were corrected to account for the inertial and frictional characteristics of the ergometer. Corrected peak power was independent of resistive load (P > 0.05), whereas uncorrected peak power varied as a quadratic function of load (P < 0.001). For males and females, optimized peak power (971 +/- 122 and 668 +/- 37 W) was lower (P < 0.01) than either the highest (1074 +/- 111 and 754 +/- 56 W respectively) or the mean (1007 +/- 125 and 701 +/- 45 W respectively) of the five values for corrected peak power. Optimized and mean corrected peak power were highly correlated both in males (r = 0.97, P < 0.001) and females (r = 0.96, P < 0.001). The difference between optimized and mean corrected peak power was 37 +/- 30 W in males and 33 +/- 14 W in females, of which approximately 15 W was due to the correction for frictional losses. We conclude that corrected peak power is independent of resistive load in males and females.  相似文献   

7.
In this study, we assessed the ventilatory response in 84 children (46 males: age 8.1 +/- 1.0 years, body mass 34.2 +/- 7.9 kg, height 1.32 +/- 0.16 m; 38 females: age 8.0 +/- 0.8 years, body mass 31.7 +/- 8.7 kg, height 1.31 +/- 0.08 m) during a cycle ergometer test to determine if there was an influence of gender on ventilatory efficiency. The test commenced at 25 W and increased by 10 W every minute. Expired air was collected through a face mask and analysed breath by breath. The ventilatory anaerobic threshold was determined according to gas exchange methods and we focused our attention on the analysis of carbon dioxide production (VCO(2)), ventilation (V(E)), the ratio V(E)/VCO(2) and its slope. Differences between the sexes at maximal power output were strongly significant for V(E) and VCO(2) (P = 0.0001 and P = 0.0004 respectively) and moderately significant for the V(E)/VCO(2) ratio (P = 0.05). The slope of V(E) versus VCO(2) was 30.8 +/- 4.2 for males and 29.4 +/- 3.2 for females, with no difference between the sexes (P = 0.1). In conclusion, although the peak values of V(E) and VCO(2) were significantly different between the sexes, there were no such differences in ventilatory efficiency during a maximal incremental test expressed as the slope of V(E)/VCO(2), at least in young children.  相似文献   

8.
In this study, we examined the effects of bovine colostrum on peak vertical jump power (VJpeak), peak cycle power (CPpeak), alactic anaerobic work capacity, resistance exercise one-repetition maxima (1-RM) and plasma insulin-like growth factor I (IGF-I) concentrations. Using a randomized, double-blind, placebo-controlled, parallel design, 51 males completed 8 weeks of resistance and plyometric training while consuming 60 g x day(-1) of bovine colostrum (n = 26) or concentrated whey protein powder (n = 25). Peak vertical jump power, peak cycle power, alactic anaerobic work capacity, 1-RM and plasma IGF-I were not different between groups at baseline (P > 0.33). Peak vertical jump power and peak cycle power were still not significantly different between groups by week 4 (VJpeak: bovine colostrum, 7231 +/- 488 W; whey protein, 7214 +/- 530 W; P = 0.99; CPpeak: bovine colostrum, 1272 +/- 202 W; whey protein, 1232 +/- 208 W; P = 0.99). By week 8, however, peak vertical jump power (bovine colostrum, 7370 +/- 503 W; whey powder, 7237 +/- 481 W; 95% confidence intervals, 54 to 170 W; P < 0.01) and peak cycle power (bovine colostrum, 1400 +/- 215 W; whey protein, 1311 +/- 192 W; 95% confidence intervals, 20 to 61 W; P < 0.01) were significantly higher in the bovine colostrum condition. Alactic anaerobic work capacity and 1-RM increased (P < 0.001), but the increases were not different between groups (P > 0.08). Plasma IGF-I did not change in either group (P = 0.55). We conclude that bovine colostrum supplementation during training significantly increased peak anaerobic power, but had no effect on alactic anaerobic work capacity, 1-RM or plasma IGF-I.  相似文献   

9.
The aim of this study was to predict indoor rowing performance in 12 competitive female rowers (age 21.3 +/- 3.6 years, height 1.68 +/- 0.54 m, body mass 67.1 +/- 11.7 kg; mean +/- s) using a 30 s rowing sprint, maximal oxygen uptake and the blood lactate response to submaximal rowing. Blood lactate and oxygen uptake (VO2) were measured during a discontinuous graded exercise test on a Concept II rowing ergometer incremented by 25 W for each 2 min stage; the highest VO2 measured during the test was recorded as VO2max (mean = 3.18 +/- 0.35 l.min-1). Peak power (380 +/- 63.2 W) and mean power (368 +/- 60.0 W) were determined using a modified Wingate test protocol on the Concept II rowing ergometer. Rowing performance was based on the results of the 2000 m indoor rowing championship in 1997 (466.8 +/- 12.3 s). Laboratory testing was performed within 3 weeks of the rowing championship. Submitting mean power (Power), the highest and lowest five consecutive sprint power outputs (Maximal and Minimal), percent fatigue in the sprint test (Fatigue), VO2max (l.min-1), VO2max (ml.kg-1.min-1), VO2 at the lactate threshold, power at the lactate threshold (W), maximal lactate concentration, lactate threshold (percent VO2max) and VEmax (l.min-1) to a stepwise multiple regression analysis produced the following model to predict 2000 m rowing performance: Time2000 = -0.163 (Power) -14.213.(VO2max l.min-1) +0.738.(Fatigue) 7.259 (R2 = 0.96, standard error = 2.89). These results indicate that, in the women studied, 75.7% of the variation in 2000 m indoor rowing performance time was predicted by peak power in a rowing Wingate test, while VO2max and fatigue during the Wingate test explained an additional 12.1% and 8.2% of the variance, respectively.  相似文献   

10.
老年人肌力流失与肌肉疲劳的肌动图研究   总被引：1，自引：0，他引：1  
研究目的：探讨老年人肌力流失对肌肉质量、最大肌力与爆发力的影响，并以肌动图（MMG）来观察老年人股外肌在不同强度表现时运动单位的激活与老化对肌肉疲劳的影响。研究方法：受试者为老年组与年轻组各10位。受试者实施股四头肌最大等长收缩、最快速度不同强度（75％、60％、45％1RM）的伸膝动作及45％的疲劳测试，记录向心期不同强度的MMG讯号。研究结果：老年组的绝对／相对最大肌力与爆发力皆明显低于年轻组（P〈0．05），而相对最大爆发力比最大肌力下降的比例高达46．2％；各强度的MMG振幅与平均功率频率皆小于年轻组（P〈0．05），显示老年组的肌纤维以慢肌为主，并发现老年组75％强度时的MMG振幅下降，表示老年人因高负荷募集不到快肌所致；MMG中位频率则无年龄差异。研究结论：老年人在静、动态力量表现有肌力流失的现象，老化对爆发力影响远超过对肌力影响，MMG讯号反应肌肉收缩的力学活动。  相似文献   

11.

Assessments of maximal intensity exercise which determine peak power output on friction‐baked cycle ergometers have fallen into two categories: correction procedures which account for changes in momentum of the ergometer's flywheel and optimization procedures which attempt to satisfy muscle force‐velocity relationships. The aim of this study was to compare performance in each procedure and so investigate assumptions which underpin the tests. Nineteen males aged 20.9 ± 0.4 years and 18 females aged 22.2 ± 0.7 years (mean ± S.E.M.), who were fully accustomed to the procedures, participated in a single experimental protocol. After a 5 min warm‐up, the subjects performed four bouts of all‐out exercise on a Monark 814E cycle ergometer against randomly assigned loads. The loads were selected to produce peak pedalling rates in the range 100–200 rev min?1 and each bout lasted 10 s. From the inverse linear relationship between applied load and peak pedalling rate, optimized peak power output (PP opt) and the accompanying pedalling rate (RPM opt) were calculated. One of the bouts used a loading equivalent to 7.5% of body weight and for this bout corrected peak power output (PP corr) and its corresponding pedalling rate (RPM corr) were calculated. The PP opt was less than PP corr in the males (915 ± 35 vs 1005 ± 32 W) and females (673 ± 33 vs 777 ± 39 W) (both P < 0.001). Similarly, RPM opt was less than RPM corr (111 ± 1 vs 128 ± 2 rev min?1 and 101 ± 1 vs 111 ± 2 rev min?1 in the males and females, respectively; P < 0.001). The results demonstrate that optimization and correction procedures produce different values of performance. These differences are probably attributable to the mechanical principles which underpin the tests.  相似文献   

12.
The purpose of this study was to assess the power output of field-based downhill mountain biking. Seventeen trained male downhill cyclists (age 27.1 +/- 5.1 years) competing nationally performed two timed runs of a measured downhill course. An SRM powermeter was used to simultaneously record power, cadence, and speed. Values were sampled at 1-s intervals. Heart rates were recorded at 5-s intervals using a Polar S710 heart rate monitor. Peak and mean power output were 834 +/- 129 W and 75 +/- 26 W respectively. Mean power accounted for only 9% of peak values. Paradoxically, mean heart rate was 168 +/- 9 beats x min(-1) (89% of age-predicted maximum heart rate). Mean cadence (27 +/- 5 rev x min(-1)) was significantly related to speed (r = 0.51; P < 0.01). Analysis revealed an average of 38 pedal actions per run, with average pedalling periods of 5 s. Power and cadence were not significantly related to run time or any other variable. Our results support the intermittent nature of downhill mountain biking. The poor relationships between power and run time and between cadence and run time suggest they are not essential pre-requisites to downhill mountain biking performance and indicate the importance of riding dynamics to overall performance.  相似文献   

13.
Maximal oxygen uptake VO(2max)) is considered the optimal method to assess aerobic fitness. The measurement of VO(2max), however, requires special equipment and training. Maximal exercise testing with determination of maximal power output offers a more simple approach. This study explores the relationship between [Vdot]O(2max) and maximal power output in 247 children (139 boys and 108 girls) aged 7.9-11.1 years. Maximal oxygen uptake was measured by indirect calorimetry during a maximal ergometer exercise test with an initial workload of 30 W and 15 W x min(-1) increments. Maximal power output was also measured. A sample (n = 124) was used to calculate reference equations, which were then validated using another sample (n = 123). The linear reference equation for both sexes combined was: VO(2max) (ml x min(-1)) = 96 + 10.6 x maximal power + 3.5 . body mass. Using this reference equation, estimated VO(2max) per unit of body mass (ml x min(-1) x kg(-1)) calculated from maximal power correlated closely with the direct measurement of VO(2max) (r = 0.91, P <0.001). Bland-Altman analysis gave a mean limits of agreement of 0.2+/-2.9 (ml x min(-1) x kg(-1)) (1 s). Our results suggest that maximal power output serves as a good surrogate measurement for VO(2max) in population studies of children aged 8-11 years.  相似文献   

14.
The aim of the present study was to examine the effect of ingesting 75 g of glucose 45 min before the start of a graded exercise test to exhaustion on the determination of the intensity that elicits maximal fat oxidation (Fatmax). Eleven moderately trained individuals (VO2max: 58.9 +/- 1.0 ml x kg(-1) x min(-1); mean +/- sx), who had fasted overnight, performed two graded exercise tests to exhaustion, one 45 min after ingesting a placebo drink and one 45 min after ingesting 75 g of carbohydrate in the form of glucose. The tests started at 95 W and the workload was increased by 35 W every 3 min. Gas exchange measures and heart rate were recorded throughout exercise. Fat oxidation rates were calculated using stoichiometric equations. Blood samples were collected at rest and at the end of each stage of the test. Maximal fat oxidation rates decreased from 0.46 +/- 0.06 to 0.33 +/- 0.06 g min(-1) when carbohydrate was ingested before the start of exercise (P < 0.01). There was also a decrease in the intensity which elicited maximal fat oxidation (60.1 +/- 1.9% vs 52.0+3.4% VO2max) after carbohydrate ingestion (P < 0.05). Maximal power output was higher in the carbohydrate than in the placebo trial (346 +/- 12 vs 332 +/- 12 W) (P < 0.05). In conclusion, the ingestion of 75 g of carbohydrate 45 min before the onset of exercise decreased Fatmax by 14%, while the maximal rate of fat oxidation decreased by 28%.  相似文献   

15.
Until recently, the physiological demands of cycling competitions were mostly reflected by the measurement of heart rate and the indirect estimation of exercise intensity. The purpose of this case study was to illustrate the varying power output of a professional cyclist during flat and mountain stages of a Grand Tour (Giro d'Italia). Nine stage recordings of a cyclist of the 2005 Giro d'Italia were monitored using a mobile power measurement device (SRM Trainingssystem, Julich, Germany), which recorded direct power output and heart rate. Stages were categorized into flat (n = 5) and mountain stages (n = 4). Data were processed electronically, and the overall mean power in flat and mountain stages and maximal mean power for various durations were calculated. Mean power output was 132 W +/- 26 (2.0 W x kg(-1) +/- 0.4) for the flat and 235 W +/- 10 (3.5 W x kg(-1) +/- 0.1) for the mountain stages. Mountain stages showed higher maximal mean power (367 W) for longer durations (1800 s) than flat stages (239 W). Flat stages are characterized by a large variability of power output with short bursts of high power and long periods with reduced intensity of exercise, whereas mountain stages mostly require submaximal, constant power output over longer periods.  相似文献   

16.
Non-circular chainrings alter the crank velocity profile over a pedalling cycle. The aim of this study was to investigate the effect of this altered crank velocity profile on the aerobic performance compared to a circular chainring (CC). Ten male non-cyclists performed two incremental maximal tests at 80?rpm on a cycle ergometer: one with a circular (Shimano) and the other with a non-circular chainring Osymetric® (Somovedi), at least 50?h apart. Each test started with a workload of 100?W lasting 3?min. During the first 12?min, the workload was increased by 30?W every 3?min. Thereafter, the workload was increased by 30?W every 2?min until exhaustion. The power output, the intra-cycle crank angular velocity and the physiological parameters were monitored continuously, averaged over the last 30?s of each increment and at exhaustion, and compared for the two chainrings. Results showed a higher maximal aerobic power attained with the non-circular chainring (362.6?±?37.9 vs. 338.8?±?32.6?W, p?相似文献   

17.
Besides its regulation by Union Cycliste Internationale, the evidence relating saddle setback to pedalling performance remains inconclusive. This study investigates the influence of saddle setback on pedalling effectiveness through two indexes: an index of pedalling force effectiveness and an index of pedalling work effectiveness. Eleven cyclists were assessed six saddle setback conditions while pedalling at a steady power output of 200 W and cadence of 90 rpm. A force sensor was integrated within the seat post to compute the centre of pressure on the saddle. From instrumented pedals, an index of force effectiveness (ratio between the force directed perpendicular to the crank arm and the total force applied to the pedal) and an index of work effectiveness (based on the minimisation of negative crank work) were calculated. In comparison with a forward position, sitting backward significantly decreased 5% cumulative total work, increased index of work effectiveness (84.2 ± 3.7 vs. 82.0 ± 4.7%), and increased index of force effectiveness (41.7 ± 2.9 vs. 39.9 ± 3.7 and 36.9 ± 0.7%). Thus, while it was previously reported that sitting more forward favours maximal power, this study demonstrates that it also leads to a decreased effectiveness in steady-state pedalling.  相似文献   

18.
There is little published data in relation to the effects of caffeine upon cycling performance, speed and power in trained cyclists, especially during cycling of approximately 60 s duration. To address this, eight trained cyclists performed a 1 km time-trial on an electronically braked cycle ergometer under three conditions: after ingestion of 5 mg x kg-1 caffeine, after ingestion of a placebo, or a control condition. The three time-trials were performed in a randomized order and performance time, mean speed, mean power and peak power were determined. Caffeine ingestion resulted in improved performance time (caffeine vs. placebo vs. control: 71.1 +/- 2.0 vs. 73.4 +/- 2.3 vs. 73.3 +/- 2.7 s; P = 0.02; mean +/- s). This change represented a 3.1% (95% confidence interval: 0.7-5.6) improvement compared with the placebo condition. Mean speed was also higher in the caffeine than placebo and control conditions (caffeine vs. placebo vs. control: 50.7 +/- 1.4 vs. 49.1 +/- 1.5 vs. 49.2 +/- 1.7 km x h-1; P = 0.0005). Mean power increased after caffeine ingestion (caffeine vs. placebo vs. control: 523 +/- 43 vs. 505 +/- 46 vs. 504 +/- 38 W; P = 0.007). Peak power also increased from 864 +/- 107 W (placebo) and 830 +/- 87 W (control) to 940 +/- 83 W after caffeine ingestion (P = 0.027). These results provide support for previous research that found improved performance after caffeine ingestion during short-duration high-intensity exercise. The magnitude of the improvements observed in our study could be due to our use of sport-specific ergometry, a tablet form and trained participants.  相似文献   

19.
An anthropometric analysis of elite Australian track cyclists   总被引：3，自引：0，他引：3  
An anthropometric analysis was conducted on 35 elite male Australian track cyclists having a mean age of 22.6 years and who had been competing on average for 9 years. The relationship of anthropometric parameters to both bicycle saddle height and cycling performance was also investigated. Subjects were allocated, for purposes of comparison, to an endurance or sprint group on the basis of their competitive event. The group members in total were ectomorphic mesomorphs of height 178 +/- 4.8 cm and weight 72.5 +/- 6.6 kg on average. Percentage of saddle height to lower limb length averaged 99 +/- 1.6%, and significant correlations existed between strength and both body mass (r = 0.57) and thigh girth (r = 0.55). No significant correlation was seen between any anthropometric parameter and performance in an individual event. Cyclists in the spint group were heavier (76.2 +/- 7.4 vs. 70.0 +/- 4.7 kg, P less than 0.01) and stronger (258 +/- 44.4 vs. 216 +/- 30.5 Nm, P less than 0.01), and had larger chest (98.2 +/- 6.2 vs. 92.4 +/- 2.9 cm, P less than 0.01), arm (33.0 +/- 2.2 vs. 30.7 +/- 1.6 cm, P less than 0.01), thigh (57.5 +/- 3.4 vs. 54.3 +/- 2.5 cm, P less than 0.01) and calf girths (37.8 +/- 1.7 vs. 36.2 +/- 1.9 cm, P less than 0.05) than cyclists in the endurance group. They were also more mesomorphic (5.3 +/- 0.7 vs. 4.7 +/- 0.8, P less than 0.05) and less ectomorphic (2.3 +/- 0.9 vs. 2.9 +/- 0.6, P less than 0.05) than the endurance cyclists.  相似文献   

20.
The aim of this study was to determine whether cyclists modify the pattern of force application to become more effective during a prolonged ride to exhaustion. Twelve competitive male cyclists completed a steady-rate exercise ride to exhaustion at 80% of their maximum power output at 90 rev x min(-1) on a cycle ergometer. Pedal force, pedal and crank angle data were collected from an instrumented bicycle for three pedalling cycles at the end of the first and final minutes of the exercise test with simultaneous video recording of the lower limbs. Kinematic and force data were combined to compute hip, knee and ankle joint moments. There were changes in the pattern of force application, joint kinematics and joint moments of force. Comparison of the first minute and the final minute ride revealed significantly increased peak effective force (340 +/- 65.0 and 377 +/- 74.8 N for the first and final minute, respectively; F1,11 = 7.44, P = 0.02), increased positive (28.4 +/- 4.5 and 30.5 +/- 4.8 N x s for the first and final minute, respectively; F1,11 = 7.80, P = 0.02) and negative angular impulses (-1.5 +/- 1.6 and -2.4 +/- 1.5 N x s for the first and final minute, respectively; F1,11 = 4.50, P = 0.06). Contrary to our initial assumptions, it would appear that riders became less effective during the recovery phase, which increased the demand for forces during the propulsive phase. Training the pattern of force application to improve effectiveness may be a useful strategy to prolong an endurance ride.  相似文献   

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