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.
Robert E. Dustman, Rita Emmerson and Donald Shearer
Andrea T. White, C. Steven Fehlauer, Rita Hanover, Stephen C. Johnson and Robert E. Dustman
Older individuals arc more likely than younger adults to exhibit symptoms of exercise intolerance at high work rates. The risks of maximal exercise in older adults increase proportionally as the number of health difficulties increase. In this study, the effects of health status, age, and gender on older adults’ ability to attain V̇O2max are examined. Sedentary volunteers (60 women, 45 men), mean age 67 ± 5 years (range 57-78 years), participated in graded maximal exercise tests on a combined arm and leg cycle ergometer. Subjects were classified into three groups based on test termination reason: attainment of V̇O2max (MAX), symptom-limited (SX), or EKG-limited (EKG). Sixty percent of men and 40% of women were classified as MAX, while 48% of women and 27% of men were characterized as SX. Thirteen percent of men and 12% of women had EKG-limited exercise tests. Those in the EKG group reported significantly more diagnoses than subjects in the MAX group (2.7 vs. 1.4. p < .05). The number of medications reported and age of the subjects did not differ across test termination categories.