Basic concepts about genes, inactivity and aging

Abstract

Remarkably, 80-year-old humans who have partaken in lifelong aerobic or strength training have maximal aerobic capacities or muscle strengths comparable with that of sedentary individuals aged 50 or 55-year-old, respectively. Such delays in functional aging are clinically significant because lower aerobic and lower strength capacities increase the risk of premature death. In this short review, we speculate that the lack of daily physical activity induces evolutionarily selected mechanisms to use or lose, one of which is related to nutritional status.

Fig. 1

Schematic depicting that physical activity delays the decline in physical function (VO_2max or muscle strength) with aging. Remarkably, a lifelong, physically trained 80-year-old has comparable values for VO_2max and muscle strength as a sedentary 50–55-year-old. Figure is modified from Fitzgerald et al. (1997), with contributions from Pearson et al. (2002), with the original slopes maintained. The frailty threshold is defined as VO_2max<18 mL/kg/min by Carr et al. (2006).