Adaptations, Safety Factors, Limitations and Trade-Offs in Human Exercise Performance

Objectives This review will describe how human exercise performance at the highest level is exquisitely orchestrated by a set of responses by all body systems related to the evolutionary adaptations that have taken place over a long history. The review will also describe how many adaptations or features are co-opted ( exaptations ) for use in different ways and have utility other than for selective advantage. Methods A review of the literature by relevant search engines and reference lists in key published articles using the terms, performance, limitations, regulation, trade-offs as related to exercise, indicates that there are at least three areas which could be considered key in understanding the evolutionary basis of human exercise performance. Results First, there is a basic assumption that exaptations have limitations or capacities which cannot be exceeded which in turn will limit our physical performance. Second, it is thought that some biological systems and tissues have additional capacity which is rarely fully accessed by the organism; referred to as a safety factor . Third, there are biological trade-offs which occur when there is an increase in one trait or characteristic traded for a decrease in another. Conclusions Adaptations have resulted in safety factors for body systems and tissues with trade-offs that are most advantageous for human performance for a specific environment.