Health versus weight as motivations for physical activity among adolescent girls have different antecedents and consequences

PURPOSE: To examine predictors and consequences of weight-related and health and well-being related motivations for physical activity (PA) among adolescent girls. METHODS: Data were collected from a longitudinal sample of 142 girls at ages 9, 11, and 13 years. Weight-related and health and well-being related motivations for PA were assessed at age 11 using the Activity Motivations Scale. Predictors of activity motivations assessed at age 9 included dietary restraint, maternal influence on weight concerns and maternal influence on PA. Body Mass Index (BMI) z-score and socioeconomic status (SES) were assessed as covariates. Outcome variables assessed at age 13 included enjoyment of PA and objectively-measured moderate to vigorous PA (MVPA). ReSUlT S: Higher weight-related activity motivation at age 11 was predicted by higher BMI, higher dietary restraint and higher maternal influence on weight concerns at age 9. Weight-related activity motivation was in turn linked with lower enjoyment of PA at age 13, which was correlated with lower MVPA. In contrast, girls with higher health and well-being related activity motivation at age 11 reported higher maternal influence on PA at age 9; no effects were noted for dietary restraint and maternal influence on weight concerns. Health and well-being motivation was in turn associated with higher enjoyment of PA at age 13. All results were independent of family SES. CONCLUSIONS: Results suggest that girls have different motivations for being physically active, each of which has different predictors and consequences. Weight-related activity motivation reflects a history of restraint and maternal influence on weight concerns and has negative effects on girls' enjoyment of PA. In contrast, health and well-being related motivation reflects a history of parental support of physical activity and is linked with higher enjoyment of PA. Intervention programs should avoid using weight-loss as a motivation for physical activity and focus instead on health and well-being. Supported by NIH Grant RO1 HD046567 and RO1 HD32973 and MO1 RR10732 ©2007The American College of Sports Medicin