Després J P, Lamarche B
Lipid Research Centre, Laval University Medical Research Centre, Sainte-Foy, Québec, Canada.
J Intern Med. 1994 Jul;236(1):7-22. doi: 10.1111/j.1365-2796.1994.tb01114.x.
Physically active individuals generally show a reduced risk of coronary heart disease (CHD) compared to the sedentary population. However, whether such reduction in CHD risk mainly results from the concomitant improvement in cardiorespiratory fitness or from the alterations in CHD risk factors has yet to be clearly established. Furthermore, there is still some controversy regarding the potential associations between endurance training-induced changes in metabolic variables considered as CHD risk factors (plasma glucose, insulin and lipoprotein levels) and the magnitude of improvement in cardiorespiratory fitness. From the results of several studies discussed in this article, it is proposed that prolonged endurance exercise of low intensity (approximately 50% VO2max), performed on an almost daily basis, seems to significantly improve metabolic variables considered as CHD risk factors through mechanisms that are likely to be independent from the training-related changes in cardiorespiratory fitness. The notion of 'metabolic fitness' is introduced and can be defined as the state of a ste of metabolic variables relevant to CHD risk and affected by the level of physical activity. Evidence available suggests that these metabolic variables are not closely related to the adaptation of cardiorespiratory fitness in response to exercise training. The concept of metabolic fitness has several implications for the prescription of exercise and for the primary and secondary prevention of CHD. Indeed, emphasis should not be placed on aiming at increasing VO2max through high-intensity exercise, but rather on producing a substantial increase in daily energy expenditure that will eventually lead to weight loss and related improvements in carbohydrate and lipid metabolism. Therefore, from a practical standpoint, although a 1 h daily walk may not have marked effects on cardiorespiratory fitness, it probably represents an exercise prescription that is likely to substantially improve 'metabolic fitness', thereby reducing the risk of CHD.
与久坐不动的人群相比，经常运动的人患冠心病（CHD）的风险通常较低。然而，冠心病风险的降低主要是由于心肺功能的相应改善，还是由于冠心病风险因素的改变，目前尚不清楚。此外，关于耐力训练引起的被视为冠心病风险因素的代谢变量（血浆葡萄糖、胰岛素和脂蛋白水平）变化与心肺功能改善程度之间的潜在关联，仍存在一些争议。根据本文讨论的几项研究结果，建议几乎每天进行低强度（约50%最大摄氧量）的长时间耐力运动，似乎能通过可能独立于心肺功能训练相关变化的机制，显著改善被视为冠心病风险因素的代谢变量。引入了“代谢适应性”的概念，可将其定义为与冠心病风险相关且受身体活动水平影响的一组代谢变量的状态。现有证据表明，这些代谢变量与运动训练引起的心肺功能适应性没有密切关系。代谢适应性的概念对运动处方以及冠心病的一级和二级预防有若干影响。事实上，不应将重点放在通过高强度运动来提高最大摄氧量上，而应放在大幅增加每日能量消耗上，这最终将导致体重减轻以及碳水化合物和脂质代谢的相关改善。因此，从实际角度来看，尽管每天步行1小时可能对心肺功能没有显著影响，但它可能代表一种运动处方，很可能会大幅改善“代谢适应性”，从而降低冠心病风险。
