Findings from three research paradigms that employed aerobic exercise as an independent variable were used to test the hypothesis that aerobic exercise improves cognitive-neuropsychological functioning. The research paradigms were animal intervention studies, cross-sectional human studies, and human intervention studies. Results from studies of animals, usually rodents, provide consistent evidence that aerobic fitness is associated with improved neurobiological and behavioral functioning. Cross-sectional studies with humans indicate a strong positive association between physical activity level and cognitive-neuropsychological performance. However, results from these studies must be interpreted cautiously, as individuals who elect to exercise or not exercise may differ on other variables that could influence cognitive-neuropsychological performance. To date, human intervention studies have not consistently demonstrated cognitive-neuropsychological improvements following exercise training. To satisfactorily test the exercise/cognition hypothesis with humans, carefully controlled intervention studies that last longer than those previously employed are needed.
The authors are with the Veterans Affairs Medical Center, Salt Lake City. R.E. Dustman and R. Emmerson are also with the College of Medicine, Univ. of Utah Medical Center. Request reprints from R.E. Dustman, Neuropsychology Research (151A), Rm G036, Bldg 2, V.A. Medical Center, 500 Foothill Dr., Salt Lake City, UT 84148.