Sex-related differences in accumulated O2 deficit incurred by high-intensity rowing exercise during childhood and adolescence.

Abstract

The aims of the present study were to determine during childhood and adolescence (i) the effect of sex on non-oxidative energy production, quantified by the accumulated oxygen deficit (AOD), and (ii) the influence of AOD on high-intensity performance. Thirty-nine boys and 35 girls aged 10-17years performed a 60s all-out test on a rowing ergometer to determine AOD and mean power output (MPO). Multiplicative allometric modelling was used to assess the concurrent effects of lean body mass (LBM) and age on AOD. AOD significantly increased with age in both sexes (p < 0.001) with boys exhibiting significantly higher AOD than girls from the age of 14years (10-11.9yr: 1.9 vs 1.9L, 12-13.9yr: 2.4 vs 2.7L, 14-15.9yr: 2.8 vs 4.6L and 16-17.9yr: 2.9 vs 5.2L, in girls and boys respectively, p < 0.001). However, a sex difference was no longer significant when AOD was analysed using an allometric model including age and LBM (p = 0.885). Finally, significant correlations were found between AOD and MPO in boys and girls but with lower evidence in girls (r2 = 0.41 vs. 0.89). Non-oxidative energy production increased more extensively in boys than girls from the age of 14years. Age and LBM accounted for the sexual differentiation of AOD during childhood and adolescence. In addition, AOD was found to be a determinant factor of high-intensity performance, more particularly in boys.