Effect of physical activity goals on aerobic physical activity: testing the mediating role of external and internal motivation

Prior work has shown that primary care patients endorse one or more of the following PA goals, weight maintenance, overall benefits, stress reduction, weight loss, tone/body shape, overall well-being, cardiovascular fitness, and increased energy. Using self-determination theory as a guide, the present study tested whether these eight goals had indirect effects on likelihood of meeting aerobic PA guidelines through internal motivation, external motivation or both. Patients (N = 642; 60.7% female; 44.5% Black; M-age = 50.26 years) were recruited from the waiting room of a primary care clinic to complete a questionnaire. Results showed that PA goals of tone/shape, weight maintenance, and stress reduction had dual, opposing influences on likelihood of meeting aerobic PA guidelines via internal and external motivation. The goal of weight loss had a negative indirect effect on likelihood of meeting guidelines via external motivation. The PA goals of overall health benefits and cardiovascular health had singular, positive indirect effects on PA via internal motivation. Well-being had a direct positive effect on PA and a negative indirect effect via external motivation. Finally, the goal of improved energy had a direct positive effect on likelihood to meet PA guidelines. Implications for clinical practice and theory development are discussed.