Validation of Cardiorespiratory Fitness Measurements in Adolescents

Cardiorespiratory fitness (CRF) is an important indicator of adolescent cardiovascular well-being and future cardiometabolic health but not always feasible to measure. The purpose of this study was to estimate the concurrent validity of the non-exercise test (NET) for adolescents against the Progressive Aerobic Capacity Endurance Run (PACER^®) and direct measures of VO_2max as well as to examine the concurrent validity of the PACER^® with a portable metabolic system (K4b^2™). Forty-six adolescents (12-17 years) completed the NET prior to performing the PACER^® while wearing the K4b^2™. The obtained VO_2max values were compared using linear regression, intra-class correlation (ICC), and Bland-Altman plots, and α was set at 0.05. The VO_2max acquired directly from the K4b^2™ was significantly correlated to the VO_2max indirectly estimated from the NET (r = 0.73, p < 0.001, r² = 0.53, ICC = 0.67). PACER^® results were significantly related to the VO_2max estimates from the NET (r = 0.81, p < 0.001, r² = 0.65, ICC = 0.72). Direct measures from the K4b^2™ were significantly correlated to the VO_2max estimates from the PACER^® (r = 0.87, p < 0.001, r² = 0.75, ICC = 0.93). The NET is a valid measure of CRF in adolescents and can be used when an exercise test is not feasible.