Physical Exertion and Mental Performance

Abstract The problem of why people in a state of fatigue make wrong decisions prompted a series of laboratory experiments of which two are described. Subjects pedalled a bicycle ergometer for varying periods of time and were tested for mental performance after different amounts of physical exertion. The results showed that a sub-maximal amount of physical exertion improved mental performance on the Brown and Poulton test of attention which relies heavily on short term memory. When the exertion was increased over longer periods of time the graph showing the relationship of mental performance to physical exertion followed the form of an inverted U. The evidence suggests that physical exertion affects mental performance by raising the level of arousal. Areas for further research are suggested.