Declining performance of master athletes: silhouettes of the trajectory of healthy human ageing?

Abstract

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 that hypothesises that a given threshold of physical activity is needed to age optimally and to maximise the 'healthspan'. Exercising at levels below the set point will result in ageing being contaminated by the unpredictable and pathological effects of inactivity. Exercise above this threshold stimulates adaptations towards maximising athletic performance, but is unlikely to have further beneficial effects on health. Thus the decades-long, controlled diminution 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.

Keywords: ageing; exercise physiology; health; performance; physical activity.

Figure 1. World record performances for the 100 m and 10,000 m track event as of June 2016 for both male and female master athletes

The data are from each age category group (5 year increments) from age 35 and also include the current world record performances by non‐master athletes. (Data from www.world‐masters‐athletics.org.) The arrows indicate the accelerated increased in performance times around the eighth decade.

Figure 2. The set point theory of healthy human ageing

A, at the set point, physical activity/exercise is sufficient to counteract the effects of inactivity and health is optimised. The decrement in physiological function that occurs through the decades is governed by the inherent ageing process. Because the decrement in physiology generated by the inherent ageing process is co‐ordinated and integrated, the amount of physical activity necessary to counter inactivity also concomitantly decreases. Health is still maintained, but at a lower physical activity level. This intertwined relationship between health and the amount of physical activity necessary to counter inactivity applies throughout the ‘healthspan’ and morbidity is compressed. The green shaded area depicts the heterogeneity of set points that could be expected in the general population. B, below the set point the negative and unpredictable effects of inactivity on physiological systems may not be perceived in the early ages, but as age progresses the added decremental effect of the inherent ageing process on an increasingly compromised physiology will result in one or more systems showing clinical disease with extended morbidity. C, individuals who engage in exercise above the set point level will also have countered the effects of inactivity and be inherently ageing. Master athletes will represent a group that are probably exercising at levels of exercise that are maximal. When engaged in competitive events the traditional performance curve will be produced. The decrement in the performance curve as age advances is due to the inherent ageing process. Analogous to the influence of the inherent ageing process at set point, the ageing process reduces performance mechanisms that are both co‐ordinated and integrated to deliver maximum performance for a given age. In later life, where the decline in performance accelerates, the levels of exercise needed to preserve maximum performance may now be approaching the set point level for that age. Individuals exercising below maximal levels, but above the set point are hypothesised to generate performance curves of a similar shape, but at lower absolute performance levels and dependent on the degree of exercise training.