The association between exercise participation and well-being: a co-twin study.

OBJECTIVE We investigated the association between leisure time exercise participation and well-being (i.e., life satisfaction and happiness) and examined the causality underlying this association. METHOD The association between exercise participation and well-being was assessed in around 8000 subjects, (age range 18-65 years) from The Netherlands Twin Registry (NTR). Causality was tested with the co-twin control method in 162 monozygotic (MZ) twin pairs, 174 dizygotic (DZ) twin and sibling pairs, and 2842 unrelated individuals. RESULTS Exercisers were more satisfied with their life and happier than non-exercisers at all ages. The odds ratio for life satisfaction given exercise participation was significantly higher than unity in unrelated pairs, and a trend was visible in DZ pairs. In MZ pairs, the odds ratio was close to unity. The pattern of odds ratios for happiness given exercise participation was similar. CONCLUSION Exercise participation is associated with higher levels of life satisfaction and happiness. This association is non-causal and appears to be mediated by genetic factors that influence both exercise behavior and well-being.