title: Depressive symptoms and cardiorespiratory fitness in obese adolescents.
abstract: OBJECTIVE
  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 < .05). Symptoms of anhedonia also were related to lower fitness levels (p < .05). These effects were observed after accounting for age, sex, race, and lean mass.
  
  
  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.
authors.affiliation: Section on Growth and Obesity, Program in Developmental Endocrinology and Genetics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892-1103, USA.
authors.forename: Lauren B
authors.initials: LB
authors.lastname: Shomaker
authors.forename: Marian
authors.initials: M
authors.lastname: Tanofsky-Kraff
authors.forename: Jaclyn M
authors.initials: JM
authors.lastname: Zocca
authors.forename: Sara E
authors.initials: SE
authors.lastname: Field
authors.forename: Bart
authors.initials: B
authors.lastname: Drinkard
authors.forename: Jack A
authors.initials: JA
authors.lastname: Yanovski
mesh_terms: D015502:Absorptiometry, Photon; D000293:Adolescent; D002648:Child; D003863:Depression / Q000503:physiopathology*; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D009765:Obesity; D010101:Oxygen Consumption / Q000502:physiology; D010809:Physical Fitness / Q000502:physiology*; D011795:Surveys and Questionnaires