Annu Rev Public Health. 2011;32:349-65. doi: 10.1146/annurev-publhealth-031210-101151.
Physical activity improves health. Different types of activity promote different types of physiologic changes and different health outcomes. A curvilinear reduction in risk occurs for a variety of diseases and conditions across volume of activity, with the steepest gradient at the lowest end of the activity scale. Some activity is better than none, and more is better than some. Even light-intensity activity appears to provide benefit and is preferable to sitting still. When increasing physical activity toward a desired level, small and well-spaced increments will reduce the incidence of adverse events and improve adherence. Prior research on the relationship between activity and health has focused on the value of moderate to vigorous activity on top of an indefinite and shifting baseline. Given emerging evidence that light activities have health benefits and with advances in tools for measuring activities of all intensities, it may be time to shift to zero activity as the conceptual starting point for study.
体育活动有益健康。不同类型的活动可促进不同类型的生理变化，并带来不同的健康结果。在各种疾病和病症的活动量范围内，风险呈曲线下降，在活动量最低端斜率最陡。有些活动比没有活动好，而更多的活动比有些活动好。即使是低强度的活动似乎也有益处，并且比久坐不动更好。当朝着期望的水平增加体育活动时，小而适度的增量将减少不良事件的发生并提高依从性。先前关于活动与健康之间关系的研究主要集中在适度到剧烈活动对不确定和不断变化的基线的价值上。鉴于有新的证据表明轻度活动对健康有益，并且随着测量各种强度活动的工具的进步，现在可能是时候将零活动作为研究的起点概念。
