Brief physical activity-related psychosocial measures: Reliability and construct validity

Background: Psychosocial factors have been related to physical activity (PA) and are used to evaluate mediation in PA interventions. Methods: Brief theory-based psychosocial scales were compiled from existing measures and evaluated. Study 1 assessed factor structure and construct validity with self-reported PA and accelerometry in overweight/obese men (N = 441) and women (N = 401). Study 2 assessed 2-week reliability and internal consistency in 49 college students. Results: Confirmatory factor analysis indicated good fit in men and women (CFI = .90; RMSEA = .05). Construct validity was supported for change strategies (r = .29–.46), self-efficacy (r = .19–.22) and enjoyment (r = .21–.33) in men and women, and for cons in women (r = –.19 to –.20). PA pros (r = –.02 to .11) and social support (r = –.01 to .12) were not supported for construct validity. Test-retest reliability ICCs ranged from .49–.81. Internal consistency alphas ranged from .55–.90. Reliability was supported for most scales with further testing needed for cons (alphas = .55–.63) and enjoyment (ICC = 49). Conclusions: Many of the brief scales demonstrated adequate reliability and validity, while some need further development. The use of these scales could advance research and practice in the promotion of PA.