Resumen de Time to Exhaustion and Time Spent at a High Percentage of [latin capital V with dot above]o2max in Severe Intensity Domain in Children and Adults
Erwan Leclair, Patrick Mucci, Benoît Borel, Georges Baquet, Helen Carter, Serge Berthoin
The aim of the study was to compare time spent at a high percentage of [latin capital V with dot above]o2max (>90% of [latin capital V with dot above]o2max) (ts90%), time to achieve 90% of [latin capital V with dot above]o2max (ta90%), and time to exhaustion (TTE) for exercise in the severe intensity domain in children and adults. Fifteen prepubertal boys (10.3 ± 0.9 years) and 15 men (23.5 ± 3.6 years) performed a maximal graded exercise to determine [latin capital V with dot above]o2max, maximal aerobic power (MAP) and power at ventilatory threshold (PVTh). Then, they performed 4 constant load exercises in a random order at PVTh plus 50 and 75% of the difference between MAP and PVTh (P[DELTA]50 and P[DELTA]75) and 100 and 110% of MAP (P100 and P110). [latin capital V with dot above]o2max was continuously monitored. The P110 test was used to determine maximal accumulated oxygen deficit (MAOD). No significant difference was found in ta90% between children and adults. ts90% and TTE were not significantly different between children and adults for the exercises at P[DELTA]50 and P[DELTA]75. However, ts90% and TTE during P100 (p < 0.05 and p < 0.01, respectively) and P110 (p < 0.001) exercises were significantly shorter in children. Children had a significantly lower MAOD than adults (34.3 ± 9.4 ml·kg-1 vs. 53.6 ± 11.1 ml·kg-1). A positive relationship (p < 0.05) was obtained between MAOD and TTE values during the P100 test in children. This study showed that only for intensities at, or higher than MAP, lower ts90% in children was linked to a reduced TTE, compared to adults. Shorter TTE in children can partly be explained by a lower anaerobic capacity (MAOD). These results give precious information about exercise intensity ranges that could be used in children's training sessions. Moreover, they highlight the implication of both aerobic and anaerobic processes in endurance performances in both populations.
