目的：比較在原地腳踏車測功儀上進行原地腳踏車運動測驗時，採用直立姿勢(upright position, UP)、彎把姿勢(drop position, DP)與俯握姿勢(aero position, AP)所測得肌電訊號與攝氧量是否有差異。 方法：實驗對象為12名健康男性（年齡23.30±0.97歲；身高175.62±6.66公分；體重72.63±7.32公斤），以平衡次序法，在原地腳踏車測功儀上，分別以直立姿勢、彎把姿勢與俯握姿勢各進行一次原地腳踏車運動測驗（每次測驗時間至少間隔48小時），分別觀察在150W、200W與衰竭時的生理反應，並將攝氧量、股外側肌均方根肌電訊號與作功負荷標準化後兩兩對應求其斜率。 結果：攝氧量在150W時，俯握姿勢大於直立姿勢，衰竭時直立姿勢大於彎把姿勢，彎把姿勢大於俯握姿勢，以上皆達顯著(p<0.5)；均方根肌電訊號值在不同騎乘姿勢下並無顯著差異；運動時間方面，直立姿勢大於彎把姿勢與俯握姿勢(p<.05)。攝氧量相對於作功負荷之斜率，在不同騎乘姿勢下並無顯著差異；均方根肌電訊號相對於作功負荷之斜率，在採用彎把姿勢時顯著大於俯握姿勢(p<.05)。 結論：以不同騎乘姿勢在原地腳踏車上進行運動測驗時會引發不同的生理上反應；採用彎把姿勢時，隨著運動強度的漸增，對股外側肌徵召情形則會越趨於明顯，並且隨著騎乘姿勢越趨於水平，則會限制人體攝氧能力，進而影響運動表現。

This study compared the physiological responses and root mean square electromyography (rms EMG) in the upright position (UP), the drop position (DP) and the aero position (AP) during the incremental test on cycle ergometer. Twelve healthy males (aged 23.30±0.97 yrs; height 175.62±6.66cm; weight 72.63±7.32kg) completed these three incremental tests on different positions respectively by counter-balance design. During these tests, we assessed the physiological responses at 150W, 200W and exhaustion and compared normalized slope of rms EMG and oxygen uptake (VO2) versus normalized power output. The results showed that: There were significant (p<.05) differences in oxygen uptake (VO2) at 150W workload, AP> UP, at exhaustion, UP>DP>AP. There were no significant differences in rms EMG at 150W and 200W. There were significant (p<.05) differences in the time to exhaustion, UP>DP and UP>AP. For normalized slope data, there were no significant differences among three positions for the oxygen uptake (VO2) versus the power output. There was a significant difference in rms EMG versus the power output, DP >AP. Different body positions affected physiological responses during the incremental test on the cycle ergometer. Vastus lateralis recruitment was proportional to exercise intensity in DP. Moreover, the closer the body to the horizontal position, the more likely the human working functions to the limited and thus the more reduced exercise performance on the cycle ergometer.