Purpose: The clinical utility of cardiorespiratory fitness (CRF) criterion-referenced standards (FITNESSGRAM) has not been tested in adolescents. We aimed to determine the ability of the FITNESSGRAM standards to discriminate between low and high cardiovascular disease (CVD) risk in a population-based sample of US adolescents.
Methods: Participants included 1247 adolescents (45.7% females) aged 12-19 yr. A submaximal walking treadmill test was used to estimate peak oxygen consumption as a measure of CRF. Participants were dichotomized based on meeting or failing the sex- and age-specific FITNESSGRAM standards. CVD risk factors included systolic blood pressure, sum of triceps and subscapular skinfolds, homeostatic model assessment (HOMA) of insulin resistance, triglycerides, and total cholesterol/high-density lipoprotein ratio. A sex- and age-specific CVD risk score was computed as the mean of these five standardized risk factors. A risk score >1 SD was considered to indicate a high CVD risk.
Results: One third of the adolescents fail to meet the FITNESSGRAM standards. Body fat and CVD risk score were significantly lower in adolescents meeting versus failing the FITNESSGRAM standards (all P < 0.003). Receiver operating characteristics curve analyses revealed that the CRF thresholds that best discriminated between low and high CVD risk were very similar to those established by FITNESSGRAM: 44.1 and 40.3 mL x kg(-1) x min(-1) among 12- to 15- and 16- to 19-yr-old boys and 36.0 and 35.5 mL x kg(-1) x min(-1) among 12- to 15- and 16- to 19-yr-old girls, respectively.
Conclusions: The CRF criterion-referenced standards established by FITNESSGRAM discriminate adolescents with a more favorable cardiovascular profile from those with a less favorable profile. Identification of children who fail to meet these standards can help detect the target population for pediatric CVD prevention strategies.