Testing validity of FitnessGram in two samples of US adolescents (12-15 years)

Eun-Young Lee; Joel D Barnes; Justin J Lang; Diego A S Silva; Grant R Tomkinson; Mark S Tremblay

doi:10.1016/j.jesf.2020.04.002

Testing validity of FitnessGram in two samples of US adolescents (12-15 years)

J Exerc Sci Fit. 2020 Sep;18(3):129-135. doi: 10.1016/j.jesf.2020.04.002. Epub 2020 May 10.

Authors

Eun-Young Lee¹, Joel D Barnes², Justin J Lang^{2

3}, Diego A S Silva⁴, Grant R Tomkinson^{5

6}, Mark S Tremblay²

Affiliations

¹ School of Kinesiology and Health Studies, Queen's University, Kingston, ON K7L2N9, Canada.
² Healthy Active Living and Obesity (HALO) Research Group, CHEO Research Institute, Ottawa, ON K1H 8L1, Canada.
³ Centre for Surveillance and Applied Research, Public Health Agency of Canada, Ottawa, ON K1A 0K9, Canada.
⁴ Research Center in Kinanthropometry and Human Performance, Federal University of Santa Catarina, Florianopolis, 88040-900, Brazil.
⁵ Department of Education, Health and Behavior Studies, University of North Dakota, ND, 58202, USA.
⁶ Alliance for Research in Exercise, Nutrition and Activity, University of South Australia, SA, 5001, Australia.

Abstract

Background: This study examined the validity of the FitnessGram® criterion-reference cut-points for cardiorespiratory fitness (CRF) based on two samples of US adolescents (aged 12-15 years). This study also established the CRF cut-points for metabolically healthy weight status based on a recent national fitness survey for the purposes of cross-validating with pre-existing cut-points including FitnessGram.

Methods: Two cross-sectional data from the 2003-2004 National Health and Nutrition Examination Survey (NHANES) (n = 378) and 2012 NHANES National Youth Fitness Survey (NNYFS) (n = 451) were used. CRF (estimated $\dot{V}$ O_2max in mL/kg/min) was estimated from a submaximal exercise test. CRF categories based on FitnessGram cut-points, a clustered cardiometabolic risk factors score and weight status were used. A series of Receiver Operating Characteristic (ROC) curve analyses were conducted to identify age- and sex-specific CRF cut-points that were optimal for metabolically healthy weight status.

Results: Based on FitnessGram cut-points, having high risk CRF, but not low risk CRF, was associated with high cardiometabolic risk (OR = 3.17, 95% CI = 1.14-8.79) and unhealthy weight status (OR = 5.81, 95% CI = 3.49-9.68). The optimal CRF cut-points for 12-13-year-olds and 14-15-year-olds were 40 and 43 mL/kg/min in males and 39 and 34 mL/kg/min in females, respectively. Compared to meeting new CRF cut-points, not meeting new CRF cut-points was associated with higher odds of showing high cardiometabolic risk (OR = 2.91, 95% CI = 1.47-5.77) and metabolically unhealthy weight status (OR = 4.47, 95% CI = 2.83-7.05).

Conclusion: FitnessGram CRF cut-point itself has rarely been scrutinized in previous literature. Our findings provide partial support for FitnessGram based on two samples of US adolescents. CRF cut-points established in this study supports international criterion-referenced cut-points as well as FitnessGram cut-points only for males. FitnessGram should be continuously monitored and scrutinized using different samples.

Keywords: Aerobic fitness; Aerobic-capacity standards; Receiver operating characteristic curve analysis.