Twenty minutes of daily vigorous physical activity (VPA) seems to be best for maximizing cardiorespiratory fitness (CRF) in adolescents, according to a study published in Pediatrics. Noting that there is no clear guidance on the intensity and duration of PA that adolescents require to maximize CRF, Benjamin David Weedon, PhD, and colleagues examined the strength of association between various PA intensity levels and CRF. Greater VPA was associated with better CRF up until approximately 20 minutes of daily VPA, at which point the relationship plateaued. In partial models, there were no associations for moderate and light PA and sedentary time with CRF. Median CRF was seen for adolescents performing 14 minutes of daily VPA. Participants in the upper versus the lower quartile of VPA had 1.03 z-scores higher CRF (95% CI, 0.75-1.30). “Further work should aim to test whether interventions based on this new target offer significant improvements in adolescent cardiometabolic health,” Dr. Weedon and colleagues wrote.
