Declining performance of master athletes: Silhouettes of the trajectory of healthy human ageing?
Analysis of world record performances by master athletes suggests an essentially linear decline with age until around the eighth decade after which performance decline accelerates. Because these records are obtained from highly trained individuals they can be viewed as being reflective of the diminution of integrative physiological prowess that occurs solely as a result of ageing, unaffected by the confounding effects of inactivity. It can also be argued that these performance profiles mirror and provide an insight into the trajectory of the physiology of the human ageing process. Here we propose a set point theory which hypothesises that a given threshold of physical activity is needed to age optimally and to maximise the “healthspan”. Exercise above this threshold stimulates adaptations towards maximising athletic performance, but is unlikely to have further beneficial effects on health. Exercising at levels below this threshold set point, will result in ageing being contaminated by the unpredictable and pathological effects of inactivity. Thus above the set point the decades-long, controlled diminution in physical capability, demonstrated at one end of the spectrum in the documented declines in athletic performance, should not be seen as a disease process. The ageing process is separate from, and independent of, exercise-mediated processes that maintain or adapt physiological function. Whether an understanding of these mechanisms will also help uncover mechanisms underpinning the ageing process itself is open to question. However, any model which does not take into account the effects of activity will not adequately describe the inherent ageing process.
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Autor / Fonte:Norman R Lazarus, Stephen D R Harridge Journal of Physiology 2016 November 3