Age and sex differences in prospective effects of health goals and motivations on daily leisure-time physical activity.

Abstract

To examine relationships between health goals, types of motivation for those goals, and daily leisure-time physical activity (LTPA), and whether these relationships differ by age or sex. From 2005 to 2008, 710 participants in and around Berlin, Germany provided life goals and motivational attributes of those goals at baseline, then reported LTPA daily for 25 days. Having (vs. not having) a goal of physical health predicted higher odds of engaging in LTPA for younger but not older participants (under age 30; OR=1.26, p=0.048), and was not related to duration of LTPA episodes. Effect of intrinsic motivation for the health goal differed by sex: for females, higher intrinsic motivation predicted higher odds of LTPA (OR=1.19, p=0.001), but was not related to duration. For males, higher intrinsic motivation predicted lower LTPA odds marginally (OR=0.70, p=0.054) but predicted longer duration (estimate=18.27 min, p<0.001). More approach motivation for the health goal predicted longer duration of LTPA episodes (0.67 min, p=0.022). One size does not fit all in LTPA intervention design. Future research should identify the mechanisms by which health goals and motivations affect health behavior.