Depressive Symptoms and Cardiorespiratory Fitness in Obese Adolescents

Abstract Purpose Depressive symptoms in adolescents have been associated with reduced physical activity. However, existing studies have relied on questionnaire measures of physical activity, which may not necessarily reflect actual energy expenditures. We sought to evaluate the relationship between depressive symptoms and objectively measured cardiorespiratory fitness among severely obese adolescents. Methods One hundred thirty-four obese (body mass index [kg/m 2 ]: ≥95th percentile) adolescent girls and boys (ages: 12–17 years) reported their depressive symptoms on the Children's Depression Inventory. Adolescents also participated in a maximal cycle ergometry exercise test to measure cardiorespiratory fitness. Body composition was assessed with dual-energy X-ray absorptiometry scanning. Results Among the 103 adolescents who reached maximal exertion, those with elevated depressive symptoms (16%) displayed poorer cardiorespiratory fitness than those without elevated depressive symptoms (maximal oxygen uptake: 1,873.2 ± 63.6 vs. 2,012.9 ± 28.6 mL/min, p p Conclusions Among obese adolescents, elevated depressive symptoms are associated with poorer objectively measured cardiorespiratory fitness. Future experimental tests should investigate whether cardiorespiratory fitness acts as a mediator of adolescent depressive symptoms' effect on obesity or obesity-related health comorbidities.