Introduction: This study examined the responses of physiological and subjective stress to moderate- and low-intensity resistance exercise (RE) with total training volumes and inter-set rest equalized, and investigated the repeated measures correlation between physiological stress markers and subjective stress responses. Methods: Eleven young males completed 3 trials in a randomized crossover order, namely-moderate-intensity RE (MOD; 4 sets of 8 repetitions at 85% 8RM), low-intensity RE (LOW; 4 sets of 8 repetitions 15 repetitions at 45% 8RM), and control (CON; resting). Physiological and subjective stress assessments were measured at pre-exercise, immediately post-exercise, 30 min post-exercise, and 60 min post-exercise time points. Changes in variables were compared using a linear mixed-effects model. A repeated measures correlation was used to assess the relationships between physiological and subjective stress responses. Results: A higher rating of perceived exertion was observed in the MOD trial (p < 0.05 vs. LOW). No significant differences were observed in the peak and mean heart rate (p > 0.05). Higher levels of mental fatigue, physical fatigue, and tension and a lower level of relaxation were only observed immediately after the MOD and LOW trials (p < 0.05 vs. CON). Cortisol levels during the recovery period were significantly higher in the MOD trial (p < 0.05 vs. CON), and inhibition of the parasympathetic nervous system (PNS) and activation of the sympathetic nervous system (SNS) during the recovery period were observed in the MOD and LOW trials (p < 0.05 vs. CON). Increases in lymphocyte counts were observed immediately after exercise in both MOD and LOW trials (p < 0.05 vs. CON). Subjective feelings were highly associated with change in lymphocyte counts, SNS, and PNS (r_(rm) = 0.561 to 0.659, -0.519 to -0.558; p < 0.05). Conclusion: These results demonstrate that low-intensity RE under an equal training volume and rest intervals can induce similar physiological stress and subjective feelings when compared to moderate-intensity RE.
前言:本研究旨在探討在相同訓練量及組間休息時間下,阻力運動強度對生理和主觀壓力反應的影響,並分析生理壓力和主觀壓力指標之間的相關性。方法:十一名年輕男性以隨機交叉設計進行三種試驗,包含中等強度阻力運動(每項動作操作4組8下,強度為85% 8RM);低強度阻力運動(每項動作操作4組15下,強度為45% 8RM);控制試驗(安靜休息)。生理壓力和主觀壓力指標於運動前、運動後立即、運動後30分鐘和運動後60分鐘測量。使用混合線性模型進行分析生理壓力及主觀壓力指標,並透過重複測量相關性分析評估生理壓力和主觀壓力指標之間的相關性。結果:中等強度阻力運動後運動自覺強度較低強度高(p<0.05);心跳率平均值與峰值於兩種強度間無顯著差異(p>0.05)。相較於控制試驗,中等和低強度阻力運動後立即,觀察到心理疲勞、身體疲勞、緊繃程度升高以及放鬆程度降低(p<0.05)。皮質醇濃度在中等強度阻力運動後顯著高於控制試驗(p<0.05)。相較於控制試驗,中等和低強度阻力運動後觀察到交感神經系統被活化及副交感神經系統被抑制(p<0.05)。相較於控制試驗,中等和低強度阻力運動後立即淋巴球數目增加(p<0.05)。主觀壓力指標與淋巴球數目、交感神經和副交感神經系統的變化呈高度相關(r_(rm)=0.561-0.659, -0.519 to 0.558; p<0.05)。結論:在訓練量與休息時間相等時,低強度阻力運動會誘發與中等強度阻力運動相似的壓力反應,不論在生理或主觀感受上。