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, r(2) = 0.53, ICC = 0.67). PACER(®) results were significantly related to the VO(2max) estimates from the NET (r = 0.81, p < 0.001, r(2) = 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, r(2) = 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.