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1.
Abstract

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   

2.
Seven 6 s sprints with 30 s recovery between sprints were performed against two resistive loads: 50 (L50) and 100 (L100) g x kg(-1) body mass. Inertia-corrected and -uncorrected peak and mean power output were calculated. Corrected peak power output in corresponding sprints and the drop in peak power output relative to sprint 1 were not different in the two conditions, despite the fact that mean power output was 15-20% higher in L100 (P < 0.01). The effect of inertia correction on power output was more pronounced for the lighter load (L50), with uncorrected peak power output in sprint 1 being 42% lower than the corresponding corrected peak power output, while this was only 16% in L100. Fatigue assessed by the drop in uncorrected peak and mean power output in sprint 7 relative to sprint 1 was less compared with that obtained by corrected power values, especially in L50 (drop in uncorrected vs. corrected peak power output: 13.3 +/- 2.2% vs. 23.1 +/- 4.1%, P < 0.01). However, in L100, the difference between the drop in corrected and uncorrected mean power output in sprint 7 was much smaller (24.2 +/- 3.1% and 21.2 +/- 2.7%, P < 0.01), indicating that fatigue may be safely assessed even without inertia correction when a heavy load is used. In conclusion, when inertia correction is performed, fatigue during repeated sprints is unaffected by resistive load. When inertia correction is omitted, both power output and the fatigue profile are underestimated by an amount dependent on resistive load. In cases where inertia correction is not possible during a repeated sprints test, a heavy load may be preferable.  相似文献   

3.
Abstract

Seven 6 s sprints with 30 s recovery between sprints were performed against two resistive loads: 50 (L50) and 100 (L100) g · kg?1 body mass. Inertia-corrected and -uncorrected peak and mean power output were calculated. Corrected peak power output in corresponding sprints and the drop in peak power output relative to sprint 1 were not different in the two conditions, despite the fact that mean power output was 15–20% higher in L100 (P < 0.01). The effect of inertia correction on power output was more pronounced for the lighter load (L50), with uncorrected peak power output in sprint 1 being 42% lower than the corresponding corrected peak power output, while this was only 16% in L100. Fatigue assessed by the drop in uncorrected peak and mean power output in sprint 7 relative to sprint 1 was less compared with that obtained by corrected power values, especially in L50 (drop in uncorrected vs. corrected peak power output: 13.3 ± 2.2% vs. 23.1 ± 4.1%, P < 0.01). However, in L100, the difference between the drop in corrected and uncorrected mean power output in sprint 7 was much smaller (24.2 ± 3.1% and 21.2 ± 2.7%, P < 0.01), indicating that fatigue may be safely assessed even without inertia correction when a heavy load is used. In conclusion, when inertia correction is performed, fatigue during repeated sprints is unaffected by resistive load. When inertia correction is omitted, both power output and the fatigue profile are underestimated by an amount dependent on resistive load. In cases where inertia correction is not possible during a repeated sprints test, a heavy load may be preferable.  相似文献   

4.
The aim of this study was to examine the consistency or reproducibility of measuring cycling peak power in children and adults. Twenty-seven pre-pubertal girls and boys and 27 female and male physical education students (age 9.8 +/- 0.5 and 24.4 +/- 4.3 years, respectively; mean +/- s) participated in the study. All participants performed five tests over 15 days and underwent a habituation session before the study. Each test included four sprints against four different braking forces. We found that braking forces of 7.5% of body weight in children and 10% of body weight in adults were too high for most of the participants to elicit maximal cycling power. Unlike the children, the physical education students improved their performance between session 1 and session 2 (1025 +/- 219 vs 1069 +/- 243 W; P < 0.001). Therefore, to obtain reproducible measures of cycling peak power, a habituation session including a complete test protocol (i.e. warm-up plus three sprints) is highly recommended. When the protocol included three sprints in children and at least two sprints in adults, measurement of cycling peak power was found to be highly reliable (test-retest coefficient of variation approximately 3%). Finally, to avoid performance fluctuations, especially over several consecutive evaluations (e.g. longitudinal studies), it is necessary to maintain high motivation in children.  相似文献   

5.
The aim of this study was to determine the relationship between force and velocity parameters during a specific multi-articular upper limb movement--namely, hand rim propulsion on a wheelchair ergometer. Seventeen healthy able-bodied females performed nine maximal sprints of 8 s duration with friction torques varying from 0 to 4 N x m. The wheelchair ergometer system allows measurement of forces exerted on the wheels and linear velocity of the wheel at 100 Hz. These data were averaged for the duration of each arm cycle. Peak force and the corresponding maximal velocity were determined during three consecutive arm cycles for each sprint condition. Individual force-velocity relationships were established for peak force and velocity using data for the nine sprints. In line with the results of previous studies on leg cycling or arm cranking, the force-velocity relationship was linear in all participants (r = -0.798 to -0.983, P < 0.01). The maximal power output (mean 1.28 W x kg(-1)) and the corresponding optimal velocity (1.49 m x s(-1)) and optimal force (52.3 N) calculated from the individual force-velocity regression were comparable with values reported in the literature during 20 or 30 s wheelchair sprints, but lower than those obtained during maximal arm cranking. A positive linear relationship (r = 0.678, P < 0.01) was found between maximal power and optimal velocity. Our findings suggest that although absolute values of force, velocity and power depend on the type of movement, the force-velocity relationship obtained in multi-articular limb action is similar to that obtained in wheelchair locomotion, cycling and arm cranking.  相似文献   

6.

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   

7.
We examined the supposition that swimmers may exhibit an imbalance in bilateral arm power output during simulated swimming exercise. Ten competitive front crawl swimmers (5 males, 5 females; age 20.5+/-2.3 years; height 1.74+/-0.09 m; body mass 72.0+/-16.7 kg; 400 m freestyle swim time 278+/-20.5 s; mean +/- s) performed four incremental (10 W x min(-1)) swim ramp tests on a computer-interfaced biokinetic swim bench ergometer. External power output from each arm was measured continuously to exhaustion. The results showed that, throughout the course of the simulated swim, external power output clearly favoured the left arm (F1,9 = 12.5, P= 0.006). This was especially evident in the final 30 s to exhaustion, when 54.0+/-3.87% of external power output was derived from the left arm versus 46.0+/-3.87% from the right arm. The disparity in external power output was further highlighted when the participants were grouped into unilateral and bilateral breathers. Unilateral breathers (n = 5) produced 57.1+/-2.62% of external power output from the left armversus 42.9+/-2.62% from the right arm (P= 0.001). Bilateral breathers (n = 5) exhibited a more balanced external power output of 51.0+/-1.82% from the left arm and 49.0+/-1.82% from the right arm (P = 0.177). Evidence of power imbalance in the simulated swimming stroke may have important implications for optimizing swim performance. The observed power imbalance may be reduced when a bilateral breathing technique is adopted.  相似文献   

8.
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   

9.
Attenuated performance during intense exercise with limited endogenous carbohydrate (CHO) is well documented. Therefore, this study examined whether caffeine (CAF) mouth rinsing would augment performance during repeated sprint cycling in participants with reduced endogenous CHO. Eight recreationally active males (aged 23?±?2?yr, body mass 84?±?4?kg, stature 178?±?7?cm) participated in this randomized, single-blind, repeated-measures crossover investigation. Following familiarization, participants attended two separate evening glycogen depletion sessions. The following morning, participants completed five, 6?s sprints on a cycle ergometer (separated by 24?s active recovery), with mouth rinsing either (1) a placebo solution or (2) a 2% CAF solution. During a fifth visit, participants completed the sprints without prior glycogen depletion. Repeated-measures ANOVA identified significant main effect of condition (CAF, placebo, and control [P?P?P?P?P?P?相似文献   

10.
It has previously been shown that the metabolic acidaemia induced by a continuous warm-up at the 'lactate threshold' is associated with a reduced accumulated oxygen deficit and decreased supramaximal performance. The aim of this study was to determine if an intermittent, high-intensity warm-up could increase oxygen uptake (VO2) without reducing the accumulated oxygen deficit, and thus improve supramaximal performance. Seven male 500 m kayak paddlers, who had represented their state, volunteered for this study. Each performed a graded exercise test to determine VO2max and threshold parameters. On subsequent days and in a random, counterbalanced order, the participants then performed a continuous or intermittent, high-intensity warm-up followed by a 2 min, all-out kayak ergometer test. The continuous warm-up consisted of 15 min of exercise at approximately 65% VO2max. The intermittent, high-intensity warm-up was similar, except that the last 5 min was replaced with five 10 s sprints at 200% VO2max, separated by 50 s of recovery at approximately 55% VO2max. Significantly greater (P < 0.05) peak power (intermittent vs continuous: 629 +/- 199 vs 601 +/- 204 W) and average power (intermittent vs continuous: 328 +/- 39.0 vs 321 +/- 42.4 W) were recorded after the intermittent warm-up. There was no significant difference between conditions for peak VO2, total VO2 or the accumulated oxygen deficit. The results of this study indicate that 2 min all-out kayak ergometer performance is significantly better after an intermittent rather than a continuous warm-up.  相似文献   

11.
In this study, we assessed the agreement between the powers recorded during a 30 s upper-body Wingate test using three different methods. Fifty-six men completed a single test on a Monark 814E mechanically braked ergometer fitted with a Schoberer Rad Messtechnik (SRM) powermeter. A commercial software package (Wingate test kit version 2.21, Cranlea, UK) was used to calculate conventional and corrected (with accelerative forces) values of power based on a resistive load (5% body mass) and flywheel velocity. The SRM calculated powers based on torque (measured at the crank arm) and crank rate. Values for peak 1 and 5 s power and mean 30 s power were measured. No significant differences (P >0.05) were found between the three methods for 30 s power values. However, the corrected values for peak 1 and 5 s power were 36 and 23% higher (P <0.05) respectively than those for the conventional method, and 27 and 16% higher (P <0.05) respectively than those for the SRM method. The conventional and SRM values for peak 1 and 5 s power were similar (P >0.05). Power values recorded using each method were influenced by sample time (P <0.05). Our results suggest that these three measures of power are similar when sampled over 30 s, but discrepancies occur when the sample time is reduced to either 1 or 5 s.  相似文献   

12.
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   

13.
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   

14.
Graded exercise tests are commonly used to assess peak physiological capacities of athletes. However, unlike time trials, these tests do not provide performance information. The aim of this study was to examine the peak physiological responses of female outrigger canoeists to a 1000-m ergometer time trial and compare the time-trial performance to two graded exercise tests performed at increments of 7.5 W each minute and 15 W each two minutes respectively. 17 trained female outrigger canoeists completed the time trial on an outrigger canoe ergometer with heart rate (HR), stroke rate, power output, and oxygen consumption (VO2) determined every 15 s. The mean (+/- s) time-trial time was 359 +/- 33 s, with a mean power output of 65 +/- 16 W and mean stroke rate of 56 +/- 4 strokes min(-1). Mean values for peak VO2, peak heart rate, and mean heart rate were 3.17 +/- 0.67 litres min(-1), 177 +/- 11 beats min(-1), and 164 +/- 12 beats min(-1) respectively. Compared with the graded exercise tests, the time-trial elicited similar values for peak heart rate, peak power output, peak blood lactate concentration, and peak VO2. As a time trial is sport-specific and can simultaneously quantify sprint performance and peak physiological responses in outrigger canoeing, it is suggested that a time trial be used by coaches for crew selection as it doubles as a reliable performance measure and a protocol for monitoring peak aerobic capacity of female outrigger canoeists.  相似文献   

15.
We examined the effect of recovery pattern on mechanical and neuromuscular responses in active men during three repeated-sprint ability tests consisting of ten 6-s cycling sprints. Within each test, the recovery duration was manipulated: constant, increasing, and decreasing recovery pattern. Maximal voluntary contractions of the knee extensors were performed before and after the repeated-sprint ability tests to assess strength and electromyographic activity [root mean square (RMS)] of the quadriceps muscle. We observed different fatigue patterns for peak and mean power output between recovery patterns, with earlier decrements recorded during the increasing recovery pattern. Total work performed over the ten sprints was also lower in the increasing recovery pattern (43.8 +/- 5.4 kJ; P < 0.05). However, the decreasing recovery pattern induced a greater overall power output decrement across the sprints (-15.8%; P < 0.05), compared with the increasing recovery pattern (-5.1%) but not the constant recovery pattern (-10.1%). The decreasing recovery pattern was also associated with higher post-sprint RMS values (+16.2%; P < 0.05). Therefore, the recovery pattern within successive short sprints may influence repeated-sprint ability, and may lead to greater post-sprint neuromuscular adjustments when recovery intervals decrease between sprints. We conclude that peripheral impairments caused the major differences in repeated-sprint ability between recovery patterns.  相似文献   

16.
Six games players (GP) and six endurance-trained runners (ET) completed a standardized multiple sprint test on a non-motorized treadmill consisting of ten 6-s all-out sprints with 30-s recovery periods. Running speed, power output and oxygen uptake were determined during the test and blood samples were taken for the determination of blood lactate and pH. Games players tended to produce a higher peak power output (GP vs ET: 839 +/- 114 vs 777 +/- 89 W, N.S.) and higher peak speed (GP vs ET: 7.03 +/- 0.3 vs 6.71 +/- 0.3 m s-1, N.S.), but had a greater decrement in mean power output than endurance-trained runners (GP vs ET: 29.3 +/- 8.1% vs 14.2 +/- 11.1%, P less than 0.05). Blood lactate after the test was higher for the games players (GP vs ET: 15.2 +/- 1.9 vs 12.4 +/- 1.7 mM, P less than 0.05), but the decrease in pH was similar for both groups (GP vs ET: 0.31 +/- 0.08 vs 0.28 +/- 0.08, N.S.). Strong correlations were found between peak blood lactate and peak speed (r = 0.90, P less than 0.01) and between peak blood lactate and peak power fatigue (r = 0.92, P less than 0.01). The average increase in oxygen uptake above pre-exercise levels during the sprint test was greater for endurance-trained athletes than for the games players (ET vs GP: 35.0 +/- 2.2 vs 29.6 +/- 3.0 ml kg-1 min-1, P less than 0.05), corresponding to an average oxygen uptake per sprint (6-s sprint and 24 s of subsequent recovery) of 67.5 +/- 2.9% and 63.0 +/- 4.5% VO2 max respectively (N.S.). A modest relationship existed between the average increase in oxygen uptake above pre-exercise values during the sprint test and mean speed fatigue (r = -0.68, P less than 0.05). Thus, the greater decrement in performance for the games players may be related to higher glycolytic rates as reflected by higher lactate concentrations and to their lower oxygen uptake during the course of the 10 sprints.  相似文献   

17.
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   

18.
Purpose: The aim of this study was to examine the effect of active versus passive recovery on 6 repeated Wingate tests (30-s all-out cycling sprints on a Velotron ergometer). Method: Fifteen healthy participants aged 29 (SD = 8) years old (body mass index = 23 [3] kg/m2) participated in 3 sprint interval training sessions separated by 3 to 7 days between each session during a period of 1 month. The 1st visit was familiarization to 6 cycling sprints; the 2nd and 3rd visits involved a warm-up followed by 6 30-s cycling sprints. Each sprint was followed by 4 min of passive (resting still on the ergometer) or active recovery (pedaling at 1.1 W/kg). The same recovery was used within each visit, and recovery type was randomized between visits. Results: Active recovery resulted in a 0.6 W/kg lower peak power output in the second sprint (95% confidence interval [CI] [ ? 0.2, ? 0.8 W/kg], effect size = 0.50, p < .01) and a 0.4 W/kg greater average power output in the 5th and 6th sprints (95% CI [+0.2,+0.6 W/kg], effect size = 0.50, p < .01) compared with passive recovery. There was little difference between fatigue index, total work, or accumulated work between the 2 recovery conditions. Conclusions: Passive recovery is beneficial when only 2 sprints are completed, whereas active recovery better maintains average power output compared with passive recovery when several sprints are performed sequentially (partial eta squared between conditions for multiple sprints = .38).  相似文献   

19.
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   

20.
Thirty-eight competitive cross-country skiers were divided into three groups to assess the reliability and validity of a new double poling ergometer. Group A (n = 22) performed two maximal 60-s tests, Group B (n = 8) repeated peak oxygen uptake tests on the double poling ergometer, and Group C (n = 8) performed a maximal 6-min test on the double poling ergometer and a double poling time-trial on snow. The correlation between the power calculated at the flywheel and the power applied at the base of the poles was r = 0.99 (P < 0.05). The power at the poles was 50-70% higher than that at the flywheel. There was a high test-retest reliability in the two 60-s power output tests (coefficient of variation = 3.0%) and no significant difference in peak oxygen uptake in the two 6-min all-out tests (coefficient of variation = 2.4%). There was a strong correlation between the absolute (W) and relative power (W x kg(-1)) output in the 6-min double poling ergometer test and the double poling performance on snow (r = 0.86 and 0.89 respectively; both P < 0.05). In conclusion, our results show that the double poling ergometer has both high reliability and validity. However, the power calculated at the flywheel underestimated the total power produced and needs to be corrected for in ergonomic estimations.  相似文献   

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