Background: A lot of evidence showed that boys and girls are at high risk of developing major or minor depression in adolescence. Increases in physical fitness have been associated with lower levels of depressive symptoms, yet the mechanisms that underlie (or mediate) this relationship have not been thoroughly examined.
Methods: 528 boys (mean age = 12.33 years) and 507 girls (mean age = 12.32 years) drawn from a suburban school district participated. Self-report measures were used to assess the mediators (body satisfaction and social physique anxiety) and the outcome (depression); the Progressive Aerobic Cardiovascular Endurance Run (PACER) in conjunction with age, Body Mass Index (BMI), and sex were used to determine an objective estimate of cardiorespiratory fitness. Path analyses were used to test the proposed models.
Results: The effects of fitness on depressive symptoms were mediated through body satisfaction and social physique anxiety; 25% to 35% of the depression variance was explained.
Conclusion: Boys' and girls' depression scores were based on the extent that their fitness levels improved their body satisfaction and lowered their social physique anxiety; body satisfaction was particularly important for girls. Thus, early adolescents' psychological well-being may be enhanced through improvements in aerobic functioning.