Age trends in maximal physical performance: comparison and evaluation of models.

Versions of five paradigmatic models of age change in maximal physical performance were compared with respect to internal and validational data. The models were termed power output, power supply, energy output-supply, motivation, and sampling. The power output models tended to be more stringent in terms of internal criteria. The model that best predicted the validational data (i.e., from studies of reaction time, strength assessment, and athletic records) was from the energy output-supply category. This model, the power output relative to power available (POrPA) model, postulates that deterioration with age in physical performance varies with the ratio of peak power output to available power: the numerator generally varies with the strength demands of the task, and the denominator varies with task duration at high power output. The implications of this model were discussed with respect to habitual physical performances in later life.