Hostility and social support explain physical activity beyond negative affect among young men, but not women, in college.

We examined social support as a moderator of cynical hostility in relation to physical activity and body mass index among college students (n = 859; M = 18.71 years (SD = 1.22); 60% women, 84% White). After controlling for negative affect in hierarchical linear regression models, greater hostility was associated with lesser physical activity among those with low social support, as expected. Greater hostility was also associated with greater physical activity among those high in social support, ps < .05. Effects were observed for men only. Hostility and social support were unrelated to body mass index, ps > .05. Young men with a hostile disposition and low social support may be at risk for a sedentary lifestyle for reasons other than negative affect.