Influence of exercise intensity on time spent at high percentage of maximal oxygen uptake during an intermittent session in young endurance-trained athletes

The purpose of this study was to compare, during a 30s intermittent exercise (IE), the effects of exercise intensity on time spent above 90% and time spent above 95% in young endurance trained athletes. We hypothesized that during a 30sIE, an increase in exercise intensity would allow an increase in due to a decrease in time to achieve 90% or 95% of Nine endurance-trained male adolescents took part in three field tests. After determination of their and maximal aerobic velocity (MAV), they performed, until exhaustion, two intermittent exercise sessions alternating 30s at 100% of MAV (IE₁₀₀) or 110% of MAV (IE₁₁₀) and 30s at 50% of MAV. Mean time to exhaustion (t _lim) values obtained during IE₁₀₀ were significantly longer than during IE₁₁₀ (p < 0.01). Moreover, no significant difference was found in expressed in absolute or relative (%t _lim) values between IE₁₀₀ and IE₁₁₀. In conclusion, an increased of 10% of exercise intensity during a 30s intermittent exercise model (with active recovery), does not seem to be the most efficient exercise to solicit oxygen uptake to its highest level in young endurance-trained athletes.