急性低氧暴露對阻力運動中自覺努力程度和生理反應之影響

Abstract

目的：探討低氧環境下進行阻力運動時，對自覺努力程度(rating of perceived exertion，RPE)和生理反應之影響。方法：參與者為規律阻力運動經驗之12名健康男性(年齡24.25 ± 2.63歲，身高176.28 ± 7.17公分，體重73.9 ± 7.95公斤)，在完成蹲舉(back squat)與仰臥推舉(bench press)最大肌力測驗後(1 repetition maximum testing，1RM testing)，依平衡次序法與重複量數之實驗設計，參與者分別先在常氧或低氧 (FiO2=15%) 環境下，進行低強度(30％ of 1RM，12反覆次數)、中強度(60％ of 1RM，6反覆次數)、高強度(90％ of 1RM，4反覆次數)之蹲舉與仰臥推舉兩種阻力運動，並在不同運動強度結束後，馬上記錄RPE(局部、全身)、心跳率、血乳酸、血氧飽和度(peripheral oxygen saturation, SPO2)和血壓。參與者休息一週後，依平衡次序法，完成另一個不同環境下的阻力測驗。結果：在仰臥推舉時，不管在低氧或常氧環境下，隨著運動強度的增加，RPE、心跳率與血乳酸也顯著增加(p≤.05)，但低氧與常氧下之RPE與血乳酸並沒有顯著差異(p>.05)，僅心跳率在低氧下顯著高於常氧下；在蹲舉時，不管在低氧或常氧環境下，隨著運動強度的增加，RPE與心跳率也顯著增加，但血乳酸則無差異。低氧與常氧下之RPE、心跳率與血乳酸皆沒有差異。另外，局部和全身RPE與心跳率和血乳酸均達顯著相關。結論：在低氧與常氧環境下進行阻力運動時，RPE確實能夠反應出阻力運動之強度，且與心跳率、血乳酸呈顯著相關，RPE的使用能有效評估低氧環境下阻力運動的強度。Purpose: This study aimed to examine the influence of acute hypoxic exposure on rating of perceived exertion (RPE) and physiological responses during resistance exercise. Methods: After completing one repetition maximum (1RM) testing, 12 resistance-trained male volunteers (24.25 ± 2.63 yrs, 176.28 ± 7.17cm, 73.9 ± 7.95kg) performed back squat and bench press exercises under hypoxia (FiO2=15%) and normoxia in a crossover counterbalanced design. All participants performed back squat and then bench press exercises at low intensity (L; 1 set of 12 repetitions at 30％1RM), moderate intensity(M; 1 set of 6 repetitions at 60％1RM) and high intensity (H; 1 set of 4 repetitions at 90％of 1RM). RPE(Local,Overall), heart rate(HR), blood lactate, peripheral oxygen saturation (SPO2) and blood pressures(BP) were obtained immediately after each set of exercises for all intensities. Results: For bench press, statistical analyses revealed RPE, HR and blood lactate increased as exercise intensity increased regardless of environmental conditions (p≤.05). No significant differences in RPE and blood lactate were found between hypoxia and normoxia(p>.05), except that HR were significantly higher in hypoxia than in normoxia. For back squat, RPE and HR increased as exercise intensity increased during either hypoxia or normoxia. However, blood lactate remained similar among all intensities. No significant differences in RPE, HR and blood lactate were found between hypoxia and normoxia. In addition, both local and overall RPE were significantly correlated with HR and blood lactate. Conclusion: When performing resistance exercise under hypoxia, RPE can reflect on exercise intensity and highly correlated with HR and blood lactate. RPE can be used to effectively monitor resistance exercise intensity under hypoxia.