Adolescence involves rapid physiological changes that may affect ventilatory control. This study used Poincaré and approximate entropy (ApEn) analyses to assess ventilatory variability and randomness during steady-state exercise in adolescents and adults. Twelve adolescents (10-14 years) and 10 adults (25-35 years) completed 20 min of submaximal cycling at 1.0 W·kg-1. The final 15 min were analyzed using Poincaré and ApEn. Continuous variables were expressed as median (interquartile range) and compared by the Mann-Whitney U-test (α = 0.05). Adolescents showed greater breathing frequency (BF) standard deviation (SD) 1 4.7 (3.7-5.4) vs. 2.6 (2.5-3.3) 1·min-1 (p -1 (p = E) relative to body weight SD1 0.02 (0.02-0.03) vs. 0.01 (0.01-0.02) L·min-1·kg (p = E 1.23 (1.20-1.32) vs. 1.01 (0.93-1.25) (p = <0.05), BF 1.26 (1.24-1.33) vs. 1.17 (1.01-1.18) (p < 0.01) and tidal volume 1.33 (1.26-1.37) vs. 1.23 (1.14-1.27) (p < 0.05). This study suggests that adolescents showed greater ventilatory variability and randomness compared to adults, likely reflecting developmental plasticity and immature ventilatory control.
Welch et al. (Fri,) studied this question.