划船選手臨界負荷無氧動力及能量消耗指標與運動表現之相關研究

Abstract

划船選手臨界負荷無氧動力及能量消耗 指標與運動表現之相關研究 中華民國94年6月 研 究 生：林信甫 指導教授：林正常

本研究主要目的在探討以不同臨界負荷（臨界動力與臨界速度）、無氧動力與能量消耗指標（效率與經濟性）評價划船測功儀上的運動表現，以確認最佳的臨界負荷預測模式，同時探討以臨界速度（CV）與臨界動力（CP）持續運動的時間與生理反應，包括心跳率（HR）、乳酸（[La-]）、氧攝取量（VO2）、二氧化碳產生量（VCO2）與換氣量（VE），考驗臨界負荷於划船運動時的生理狀態是否穩定。本研究受試對象為國內優秀的女性西式划船選手15名（年齡 20.73± 1.44歲、身高164 ±0.35公分、體重56.64±4.38公斤），經平衡次序法，所有受試者皆在划船測功儀上（Concept II），接受不同距離（400公尺、600公尺、800公尺、1000公尺）與時間（90秒、240秒、600秒、1200秒）的運動測驗，以線性模式分析分別獲得CV（4.00 ±0.14m/s）與CP（139.49 ±20.37W）；其次進行漸進負荷測驗、CV與CP的20分鐘持續運動測驗；實驗過程中以Vmax29能量代謝系統、YSI1500乳酸分析儀分別測得VO2max（2.47±0.47L）與AT4（157.81 ±22.08W）以及持續運動中的呼吸生理變化；最後進一步經2000公尺衝刺測驗獲得運動表現成績（493.44±19.02秒）與30秒無氧動力測驗獲得無氧能力（6912.14±895.64W），平均無氧動力（323.17±26.70W），疲勞指數（3.77±2.55％）。經皮爾遜積差相關檢定與重複量數變異數分析的結果顯示，CV與CP與2000公尺划船運動成績皆有顯著相關（r＝－0.97、－0.81，p<.05），其中CV的相關程度大於VO2max與AT4（r＝－0.85、－0.84，p<.05），但划船效率以及經濟性皆無相關。進一步經多元逐步迴歸分析顯示，以CV配合疲勞指數（FI）為預測2000公尺划船成績的最佳預測模式（T2000=−131.83CV（m/s）−1.00FI（%）+1023.91, SEE=4.10s, p<.05）決定係數高達0.96。在CV持續運動時間為14±4分鐘，運動過程中[La-]、HR、VO2、VE皆不會出現穩定狀態，而VCO2則無變化；同時在CP強度下，持續運動時間為20分鐘，VO2、VCO2會出現穩定狀態，但是[La-]、HR以及VE皆隨著運動時間的增加而上升。因此，本研究發現划船選手的CV越高，2000公尺的運動表現越佳，較CP而言，CV是划船運動較佳的臨界負荷指標，且配合疲勞指數構成最佳的成績預測模式。同時，CV並無法持續長時間的運動，且各項生理指標皆無法呈現穩定狀態，而CP強度下雖然可以持續20分鐘，但並非所有生理狀態均呈現穩定。

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.