The Effects of Moderate Exercise on Bayesian Choices

Exercise is known to improve health along many dimensions. Decision making is an understudied dimension of one’s (behavioral) health where exercise effects are not well-known. Because certain physiological changes are known to impact decision making, exercise may modulate decisions via its effect on physiological or psychological variables. We examine how moderate aerobic exercise affects outcomes and the decision process in an incentivized Bayesian choice task. Twenty-six adult subjects (30-60 years old, 14 female) are administered the decision task under both exercise and no-exercise conditions. Our results indicate that the estimated decision model changes post-exercise such that exercise increases the decision weight subjects place on new evidence in making their choices. This same effect is found among those with higher fitness levels, which is a long-term result of regular exercise, but both of these effects appear gender-specific. Accuracy of choice, however, is not significantly affected by the exercise treatment. The fact that exercise leads to a shift in relative decision weights on evidence compared to base rate information is important in terms of identifying when exercise and/or fitness may lead to improved versus harmed decision making in more complex environments. JEL classification: C91, I12, D83