Physical Activity in Adolescence and Cannabis Use in Adulthood: Evidence from the National Longitudinal Study of Adolescent Health in the United States (1994-2018)

Adolescence is a key period when many individuals experience changes in their physical activity behaviors and start using cannabis, making it a time to both promote physical activity and prevent cannabis use. This study examined the association between physical activity in adolescence and cannabis use in adulthood. We analyzed data from 2,196 adolescents who participated in Waves I to V of the National Longitudinal Study of Adolescent Health (Add Health) from 1994-2018. Participants had a mean age of 15 at baseline and were followed for 24 years. Using weighted mixed-effects Poisson models, we estimated the association between physical activity in Wave 1 (1994-1995) and time-varying cannabis use across subsequent waves, adjusting for sociodemographic factors and baseline substance use. Results were stratified by type of physical activity (i.e., sports, exercise). At baseline, participants engaged in physical activity about 6 times per week on average. Age, sex, cigarette smoking, and alcohol use were significantly associated with cannabis use over time. Physical activity was associated with lower cannabis use when defined as daily versus less than daily (IRR = 0.63, 95% CI = 0.41, 0.95; p = 0.03), but not when analyzed as a continuous frequency variable (IRR = 1.01, 95% CI = 0.99, 1.02; p = 0.483). Participation in sports and exercise showed a protective association when categorized by weekly frequency. These findings suggest that physical activity may protect against cannabis use, although the association depends on how activity is measured. Future research should explore the association of different types and contexts of physical activity on cannabis use over time.