Moderate vs. high exercise intensity: Differential effects on aerobic fitness, cardiomyocyte contractility, and endothelial function
Moderate vs. high exercise intensity: Differential effects on aerobic fitness, cardiomyocyte contractility, and endothelial function
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DOI：
10.1016/j.cardiores.2005.03.010
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发表时间：
2005-07-01
影响因子：
10.8
通讯作者：
Ellingsen, O
中科院分区：
文献类型：
--
作者：
Kemi, OJ;Haram, PM;Ellingsen, O
目的：目前的指南对心血管疾病预防和康复中的运动强度存在争议。虽然高强度训练会导致体能和最大摄氧量（VO 2 max）的大幅增加，但中等强度的训练通常也同样有效。需要进行临床前对照研究和随机临床试验，以确定中等强度与高强度的定期运动是否更有益。因此，我们评估了10周高强度与中等强度（MOD）运动强度对综合和细胞功能的相对有效性。方法：SD大鼠每周5天，每天以最大摄氧量的85%-90%（HIGH）或65%-70%（MOD）进行跑台运动。结果：HIGH和MOD分别使VO 2 max增加71%和28%。这被强度依赖性心肌细胞肥大所掩盖，HIGH和MOD分别为14%和5%。心肌细胞功能（缩短率）增加45%和23%，收缩率下降43%和39%，舒张率下降20%和10%，在高和MOD，分别。在HIGH和MOD时，Ca ~（2+）瞬时时程增加收缩/舒张，而Ca ~（2+）敏感性分别增加40%和30%。两种强度下颈动脉内皮功能的改善相似。与久坐不动相比，乙酰胆碱诱导的舒张的EC 50在HIGH中降低4.3倍（p < 0.05），在MOD中降低2.8倍（p < 0.20）; HIGH与MOD的差异为1.5倍（p =0.72）。多元回归分析显示，收缩期Ca 2+升高率和舒张期心肌细胞再充盈率是影响VO 2 max的主要因素，细胞肥大、收缩力和血管舒张力也与VO 2 max显著相关。VO 2 max、心肌细胞尺寸和收缩能力之间的密切相关性表明，高强度的益处显著更高，而中等水平的内皮功能似乎相当。因此，运动强度成为未来临床前和临床研究的重要变量。(c)2005年欧洲心脏病学会。Elsevier B. V.出版，保留所有权利。
Objective: Current guidelines are controversial regarding exercise intensity in cardiovascular prevention and rehabilitation. Although high-intensity training induces larger increases in fitness and maximal oxygen uptake (VO2max), moderate intensity is often recommended as equally effective. Controlled preclinical studies and randomized clinical trials are required to determine whether regular exercise at moderate versus high intensity is more beneficial. We therefore assessed relative effectiveness of 10-week HIGH versus moderate (MOD) exercise intensity on integrative and cellular functions. Methods: Sprague-Dawley rats performed treadmill running intervals at either 85%-90% (HIGH) or 65%-70% (MOD) Of VO2max day, 5 days per week. Weekly VO2max-testing adjusted exercise intensity.Results: HIGH and MOD increased VO2max by 71% and 28%, respectively. This was paralleled by intensity-dependent cardiomyocyte hypertrophy, 14% and 5% in HIGH and MOD, respectively. Cardiomyocyte function (fractional shortening) increased by 45% and 23%, contraction rate decreased by 43% and 39%, and relaxation rate decreased by 20% and 10%, in HIGH and MOD, respectively. Ca2+ transient time-courses paralleled contraction/relaxation, whereas Ca2+ sensitivity increased 40% and 30% in HIGH and MOD, respectively. Carotid artery endothelial function improved similarly with both intensities. EC50 for acetylcholine-induced relaxation decreased 4.3-fold in HIGH (p < 0.05) and 2.8-fold in MOD (p < 0.20) as compared to sedentary; difference HIGH versus MOD 1.5-fold (p =0.72). Multiple regression identified rate of systolic Ca2+ increase and diastolic myocyte relengthening as main variables associated with VO(2)max Cell hypertrophy, contractility and vasorelaxation also correlated significantly with VO2max.Conclusions: The present study demonstrates that cardiovascular adaptations to training are intensity-dependent. A close correlation between VO2max, cardiomyocyte dimensions and contractile capacity suggests significantly higher benefit with high intensity, whereas endothelial function appears equivalent at moderate levels. Thus, exercise intensity emerges as an important variable in future preclinical and clinical investigations. (c) 2005 European Society of Cardiology. Published by Elsevier B.V. All rights reserved.