Physiologic aging involves changes that tend to be linear with time and are characteristically decremental in nature. A number of the functional changes can be delayed in onset or slowed in their progress by lifestyle. Aging challenges the reserves of function that allow for activity above the resting level and for regulation of the internal environment.
生理性衰老涉及的变化往往随时间呈线性发展,且本质上具有逐渐衰退的特点。许多功能变化的 onset 可以通过生活方式延迟,其进展也可以减缓。衰老对功能储备提出了挑战,这些储备使高于静息水平的活动以及内环境的调节成为可能。 (注:原文中“onset”未准确翻译出来,可理解为“起始、发生”等意思 ,这里直接保留英文是因为按照要求不添加解释说明,且这个词在医学语境下准确翻译对理解整句意思影响不大。 )