To determine the effects of physical exercise on the process of fantasizing, 40 college and graduate students gave responses to Holtzman inkblot cards in two counterbalanced conditions while seated in a comfortable lounge chair and pedaling a stationary exercise bicycle at a mild level of exertion. Responses were scored for verbal fluency, as determined by word count; human, animal, inanimate, and total movement; and for measurement of primary-process thinking. The results lead to the conclusion that low levels of physical activity exert dramatic effects upon perceptual and cognitive functioning which are probably relevant to the outcome of exercise-oriented programs of psychotherapy.