Shephard R J
Faculty of Physical Education and Health, University of Toronto, Toronto, ON, CANADA.
Med Sci Sports Exerc. 2001 Jun;33(6 Suppl):S400-18; discussion S419-20. doi: 10.1097/00005768-200106001-00008.
To examine the importance of relative versus absolute intensities of physical activity in the context of population health.
A standard computer-search of the literature was supplemented by review of extensive personal files.
Consensus reports (Category D Evidence) have commonly recommended moderate rather than hard physical activity in the context of population health. Much of the available literature provides Category C Evidence. It has often confounded issues of relative intensity with absolute intensity or total weekly dose of exercise. In terms of cardiovascular health, there is some evidence for a threshold intensity of effort, perhaps as high as 6 METs, in addition to a minimum volume of physical activity. Decreases in blood pressure and prevention of stroke seem best achieved by moderate rather than high relative intensities of physical activity. Many aspects of metabolic health depend on the total volume of activity; moderate relative intensities of effort are more effective in mobilizing body fat, but harder relative intensities may help to increase energy expenditures postexercise. Hard relative intensities seem needed to augment bone density, but this may reflect an associated increase in volume of activity. Hard relative intensities of exercise induce a transient immunosuppression. The optimal intensity of effort, relative or absolute, for protection against various types of cancer remains unresolved. Acute effects of exercise on mood state also require further study; long-term benefits seem associated with a moderate rather than a hard relative intensity of effort.
The importance of relative versus absolute intensity of effort depends on the desired health outcome, and many issues remain to be resolved. Progress will depend on more precise epidemiological methods of assessing energy expenditures and studies that equate total energy expenditures between differing relative intensities. There is a need to focus on gains in quality-adjusted life expectancy.
探讨在人群健康背景下，体力活动的相对强度与绝对强度的重要性。
在对文献进行标准计算机检索的基础上，补充查阅大量个人档案。
共识报告（D类证据）通常建议在人群健康背景下进行中等强度而非高强度的体力活动。现有许多文献提供的是C类证据。这些文献常常将相对强度问题与绝对强度或每周运动总量混淆。就心血管健康而言，除了最低运动量外，有证据表明存在一个努力的阈值强度，可能高达6代谢当量。中等强度而非高强度的体力活动似乎最有助于降低血压和预防中风。代谢健康的许多方面取决于活动总量；中等相对强度的努力在动员身体脂肪方面更有效，但较高相对强度可能有助于增加运动后的能量消耗。似乎需要较高相对强度来增加骨密度，但这可能反映出活动量的相应增加。高强度的相对运动强度会引起短暂的免疫抑制。预防各类癌症的最佳努力强度（相对强度或绝对强度）仍未明确。运动对情绪状态的急性影响也需要进一步研究；长期益处似乎与中等而非高强度的相对努力强度有关。
努力的相对强度与绝对强度的重要性取决于期望的健康结果，许多问题仍有待解决。进展将取决于更精确的评估能量消耗的流行病学方法以及使不同相对强度之间的总能量消耗相等的研究。有必要关注质量调整生命年的增加。
