A sizable body of evidence points to the ability of resistance training undertaken in later life to reduce the risk of suffering age-related disease, and to improve the prognosis for existing diseases. In a glass half empty sort of a viewpoint, we might take this to mean that next to nobody puts in the effort necessary to maintain the body in an optimal state of health. A surprisingly sizable fraction of the declines in strength and fitness observed in the wealthier parts of the world are actually self-inflicted, not an inevitable consequence of aging. This is particularly apparent in comparisons with hunter-gatherer populations, where exercise and fitness persist into late middle age, and the declines that are inevitable are lessened.
The progressive decline of skeletal muscle mass and strength with aging is collectively referred to as sarcopenia, and is prognostic for mobility disability and chronic disease risk. Regular physical activity (defined here as any bodily movement produced by the contraction of skeletal muscle that increases energy expenditure) and exercise (physical activity that is planned, structured, and repetitive) are cornerstones in the primary prevention of chronic diseases and also for mitigating risk of mobility disability in older persons.
Resistance exercise (RE) and aerobic exercise (AE) are modalities of exercise that are traditionally conceptualized as existing on opposite ends of an exercise continuum in terms of the phenotypes they lead to. A common misconception is that RE training (RET) and AE training (AET) also result in separate health benefits, but we propose this is an artifact of the greater volume of data that currently exists for AET as opposed to RET. Currently, most physical activity guidelines advise, as their primary message, that older adults should perform at least 150 min of moderate-to-vigorous or 75 min of vigorous AET weekly for the reduction of chronic disease risk and maintenance of functional abilities. However, there is an emerging body of evidence to suggest that RET can be as effective as AET in reducing chronic disease risk and is particularly potent for maintaining mobility in older adults.
It may be that RET is more effective than AET in some regards; the converse is likely also true. We posit that the perceived divergent exercise mode-dependent health benefits of AET and RET are likely small in most cases. In this short review, our aim is to examine evidence of associations between the performance of RET and chronic health disease risk (mobility disability, type 2 diabetes, cardiovascular disease, cancer). We also postulate on how RET may be influencing chronic disease risk and how it is a critical component for healthy aging. Accumulating evidence points to RET as a potent and robust preventive strategy against a number of chronic diseases traditionally associated with the performance of AET, but evidence favors RET as a potent countermeasure against declines in mobility. On the basis of this review we propose that the promotion of RET should assume a more prominent position in exercise guidelines particularly for older persons.