The Age-Performance Relationship

PURPOSE: The physiological traits characterizing human capacities (the ability to move, reproduce or perform tasks) change with age: performance is limited at birth, increases to a maximum, then decrease back to zero at death. Both physical and intellectual skills follow similar ontogenies. The development of sport and chess performances during the lifetime was previously investigated at two different scales: the individual athletes’ careers and the world record by age class in 25 Olympic sports and in elite chess players. For all data sets, a biphasic pattern of growth and decline is described by a simple equation and the two processes (growth and decline) are exponential and operate throughout the lifetime, starting at age 0. Here we aim to demonstrate that this biphasic behaviour is probably widespread among biological phenomena and compare the characteristics of the biphasic patterns such as the age of peak performance. METHODS: Performances data were gathered for human (200, 400 and 800m races, n=5065, 5013 and 5080, respectively), greyhound (480m competitions, n=47991), mice (distance run on wheels during 24h, n=14241) and Caenorhabditis elegans (using an experimental eletrotaxis device). Other data-sets included performance in face recognition, lung functionality, muscle width in human-related systems plus physical performance in greyhounds and mice photosynthesis yield in cotton leaves, the aboveground net primary production in Picea abies with stand age. RESULTS: A U-inversed biphasic pattern is found in all the studied processes, in both the athletic (human Olympians and elite greyhound) and non-athletic (mice, Caenorhabditis elegans) species. The pattern is always asymmetrical and we found that the estimated ages of peak performance always occur in the early part of life: 20.6 % ±6.7% of estimated lifespan. CONCLUSIONS: The pattern is robust, whatever the type of effort and duration: free activity vs. constrained running or overall distance traveled vs. maximum speed. Our results suggest a similar age-related pattern in very different species. The description of the physiological limits shows that there is no brutal transition between the developmental and senescent periods. It thus questions the narrowed link between those two processes.