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 as well as to examine the concurrent validity of the PACER with a portable metabolic system (K4b). Forty-six adolescents (12-17 years) completed the NET prior to performing the PACER while wearing the K4b. The obtained VO values were compared using linear regression, intra-class correlation (ICC), and Bland-Altman plots, and α was set at 0.05. The VO acquired directly from the K4b was significantly correlated to the VO indirectly estimated from the NET ( = 0.73, < 0.001, = 0.53, ICC = 0.67). PACER results were significantly related to the VO estimates from the NET ( = 0.81, < 0.001, = 0.65, ICC = 0.72). Direct measures from the K4b were significantly correlated to the VO estimates from the PACER ( = 0.87, < 0.001, = 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.