Abstract
Background: Evidence suggests that adolescents’ physical activity (PA) influences mental health in young adulthood. However, it remains unclear whether this association reflects a cumulative effect or is driven by PA during specific periods in adolescence.
Purpose: To determine whether PA accumulated throughout adolescence or at certain stages of adolescence more strongly predicts positive mental health in early adulthood.
Methods: 536 participants in the MATCH longitudinal study self-reported their PA annually over eight years during adolescence, and their positive mental health across four years in early adulthood. Adolescent PA history was computed as either the Cumulative Index of Exposure (CIE), which captures the total PA, or the Weighted Cumulative Exposure (WCE), assigning specific weights to exposure at each age. Linear mixed models were used to examine associations between adolescent PA history (CIE or WCE) and early adult positive mental health.
Results: Positive mental health declined during early adulthood (β = -1.11; 95% CI: -1.73 to -0.49). Total adolescent PA (CIE) and PA accumulated toward the end of adolescence (WCE) were both positively associated with better initial levels of positive mental health in early adulthood. None of the total adolescence PA or PA accumulated at specific periods of adolescence was associated with a change in positive mental health during early adulthood.
Discussion: These findings confirm long-term benefits of adolescent PA on early adult mental health and identify late adolescence as an important period. Efforts to promote sustained PA, especially in later adolescence, may help people maintain better mental health for many years.
