ORIGINAL INVESTIGATIONS: PDF OnlyPhysiological responses to treadmill exercise in females adult-child differencesROWLAND, THOMAS W.; GREEN, GERALD M. Author Information Departments of Pediatrics and Internal Medicine, Baystate Medical Center, Springfield, MA 01199 Medicine & Science in Sports & Exercise: October 1988 - Volume 20 - Issue 5 - p 474-478 Free Abstract Physiologic differences between children and adults during treadmill exercise have been defined principally utilizing male subjects. To determine whether these variations are valid in females, responses to treadmill testing to exhaustion in 18 premenarchal girls were compared with an equal number of young adult females (mean age 28.7 yr). Except at the lowest workload, the girls demonstrated significantly higher oxygen consumption and ventilation per body weight at maximal and sub-maximal speeds. Differences in submaximal running economy disappeared when V̇O2 was related to body surface area. The children exhibited a greater respiratory rate and lower tidal volume (per kilogram) at a given ventilation as well as inferior breathing efficiency (higher ventilatory equivalent for oxygen). The absolute ventilatory breakpoint was higher in the girls, but there was no significant difference in this parameter between the groups when expressed as percent V̇O2max. The heart rate at the ventilatory breakpoint was greater in the girls, however. These findings indicate that pre- and post-menarchal females exhibit similar differences in physiologic responses to treadmill running as previously observed in adult and child male subjects. ©1988The American College of Sports Medicine