The constructs of social cognitive theory (SCT) explained little of the variance of objectively measured physical activity (PA) in a sample of inactive people with multiple sclerosis (MS) who volunteered for a recent exercise trial. The only significant variable was exercise self-efficacy, which confirms the importance of enhancing it through PA interventions. Participants (n=65) completed several questionnaires and were assessed using standardized outcome measures as part of a cross-sectional analysis of baseline data from a randomized controlled trial (Step it Up). Researchers found:

• The bivariate correlation analysis indicated that of all SCT constructs, only exercise self-efficacy was significantly correlated with energy expenditure (EE) (r = 0.297).
• Multiple linear regression analysis found that exercise self-efficacy independently explained 9% of the variance in EE (R² = 0.088).
• A model including exercise self-efficacy, exercise goal setting, exercise planning, and exercise benefits explained 17% of the variance in EE (F_4,54 = 2.741, R² = 0.169).
• In this model, only exercise self-efficacy was significantly associated with EE scores (Exercise Self-Efficacy Scale β = .320).