H. Hebestreit et al., PLASMA METABOLITES, VOLUME AND ELECTROLYTES FOLLOWING 30-S HIGH-INTENSITY EXERCISE IN BOYS AND MEN, European journal of applied physiology and occupational physiology, 72(5-6), 1996, pp. 563-569
It has been shown that boys recover faster than men following brief, h
igh-intensity exercise. Better to understand this difference, plasma m
etabolite concenration, volume, electrolyte concentration [electrolyte
], and hydrogen ion concentration [H+] changes were compared in five p
repubescent boys [mean age 9.6 (SD 0.9) years] and 5 men [mean age 24.
9 (SD 4.3) years] following 30-s, all-out cycling. Blood was collected
prior to, at the end, and at the Ist, 3rd and 10th min following exer
cise. At the 10th min of recovery, the men's lactate concentration was
14.2 (SD 1.8) mmol . 1(-1) and [H+] was 66.1 (SD 5.9) nmol . 1(-1), c
ompared with 5.7 (SD 0.7) mmol . 1(-1) and 47.5 (SD 1.2) nmol . 1(-1)
respectively, in the boys (P < 0.01 for both). The glycerol concentrat
ion was higher in the boys at the end of exercise and until the 3rd mi
n of recovery. Plasma volume (PV) decreased more in the men [16.9 (SD
3.0)%] than in the boys [9.4 (SD 2.8)%]. In both groups, [electrolyte]
increased after exercise, tending to be higher in the men. Recovery o
f plasma [electrolyte] and PV started earlier in the boys (Ist min) th
an in the men (3rd min). These findings would support the notion of a
lesser reliance on glycolytic energy pathways in children and may expl
ain the faster recovery of muscle power in boys compared to men.