| Summary: | 博士 === 國立臺灣師範大學 === 體育學系 === 93 === Application of critical concepts, anaerobic power and energy expenditure in predicting rowing performance
June,2005 Hsin-Fu Lin
Advisor: Jung-Charng Lin,
Abstract
Critical velocity (CV) and critical power (CP) have been proposed to be effective indirect anaerobic threshold methods in monitoring training and predicting performance of rowing respectively. The purpose of this study was to compare these two indexes in predicting indoor rowing performance by combining different physiological variables, including maximal oxygen uptake ( VO2max ), anaerobic threshold (AT4) and modified Wingate test, which are important physiological variables in endurance performance. In addition, whether or not the physiological variables (VO2, VCO2, VE, HR, [La-]) under these two critical intensities were stable was also examined. Fifteen elite female rowers (age 20.73± 1.44 years, height 1.64 ±0.35m, weight 56.64±4.38kg) were recruited in this study. VO2max (2.47 ±0.47L) and AT4(157.81 ±22.08W) were measured during a discontinuous graded exercise test, starting at 100W, on a Concept II ergometer increased by 25 W for each 3-min stage. Four test times of duration 90s, 240s, 600s, and 1200s were used to determine CP (139.49 ±20.37W), whereas CV( 4.00 ±0.14m/s) was estimated by 400m, 600m, 800m, 1000m maximal exertion trials in different days as well by using Linear distance-time model. Peak power (353.48 ±27.71W), maximum power (350.12 ±26.72W), minimum power (336.85 ±21.58W), mean power (314.44 ±27.87W), fatigue index (max power - min power/ mean power) were obtained using a modified Wingate test protocol (30s sprint) on the ergometer. Physiological variation of intensity at CV and CP, including VO2, VCO2, VE, HR, [La-], were measured every 5 minutes in 20-min constant rowing tests. The results of study showed that VO2max, AT4, CP, CV, peak power, mean power were significantly correlated with 2000 indoor rowing performance (r=−0.84, −0.85, −0.81, −0.97, −0.66, −0.67, P<0.01). By submitting mean power, fatigue index, VO2max, AT4 with each index to a stepwise regression analysis, it produced two individual critical concept models as following to predict 2000 indoor rowing performance: CV model: T2000= −131.83 CV(m/s)−1.00 fatugue index(%) +1023.91 (R2=0.96, SEE=4.10, p<.05); CP model: T2000=−22.59 VO2max(L/min)−.38AT4(W)+608.58 (R2 =0.82, SEE=8.05, p<.05). When rowing at CV on indoor ergometer (14±4 min), VO2, VE, HR, [La-] didn’t reach steady state and VCO2 was not different at different time points. Under CP, VO2, VCO2 didn’t change with time, however, there were significant difference of VE, HR, [La-] at different time points. Our findings in this study indicated that CV has more predictive power, representing as anaerobic threshold, than AT4 to predict rowing performance. Besides CV, fatigue index from modified Wingate test is also an important determinant for 2000-m performance of female rowers. Therefore, comparing with CP, CV could be used when applying critical concept in training and evaluate indoor performance in rowing. In addition, both two-parameter-derived CV and CP in rowing do not represent sustainable steady state intensities.
Key words: critical velocity, critical power, anaerobic power, energy expenditure, rowing, performance.
|
|---|
