Age-Related Exercise Performance in Growing Children and Adolescents Assessed by Peak and Submaximal Cardiopulmonary Exercise Testing Parameters

Background Age-related changes in exercise performance during adolescence by cardiopulmonary exercise testing (CPET) are complex. Methods Peak and submaximal CPET parameters by cycle ergometer were retrospectively analyzed to characterize how age and sex affect exercise performance. Results A total of 165 subjects were divided into six groups by their ages: ≤ 11 years old (yo) (24 males, 20 females), 12 to 15 yo (34 males, 41 females), and ≥ 16 yo (27 males, 19 females). Peak heart rate (HR) was comparable among all groups. Peak systolic blood pressure, peak oxygen consumption (VO2), peak work rate (WR), peak oxygen pulse (OP), and peak minute ventilation (VE) showed age-dependent increase in both sexes with more progressive increase in males than in females. A submaximal slope value of D[VO2/kg]/DHR and peak OP/kg were comparable in all males but lower in older females (³ 12 yo) than in the younger group. DHR/D[WR/kg], HR dependency, revealed progressive decrease with age in males but were comparable in all females. Regression lines between weight and peak VO2 demonstrated significant age-related increase of slope in males but not in females, suggesting robust age-related skeletal muscle enhancement predominantly in males. Gradual increases in ventilatory efficiency (lower ΔVE/ΔVCO2) and peak respiratory exchange ratio were noted with increase in age independent of sex. Conclusion Age-related increase in exercise performance during adolescence is complex, characterized by physical growth, sex-dependent pubertal changes, and sex-independent enhanced functional maturation. By incorporating peak and submaximal CPET parameters, underlying physiology of exercise performance may be further explained.