Effect of training and detraining on catecholamine responses to sprint exercise in adolescent girls.

Training is well known to influence catecholamine responses to exercise. In women, this training effect is still not well characterized and has been studied mostly in adults. Hence, we investigated in this longitudinal study, the effects of a 6-month sprint training program followed by 5 months of detraining on plasma catecholamine responses to a sprint exercise in young female subjects. Twelve healthy adolescent girls [training group (TG), n=6; control group (CG), n=6] took part in our study. TG participated in 6 months of supervised sprint training program (3 days/week) and has no training past whereas, CG continued with it's normal activity. A 6s-sprint test was performed on a cycle ergometer before training (P1) and after training (P2) in both the groups. TG only realized a 6s-sprint test after 5 months of detraining (P3). Blood lactate concentrations (La) as well as plasma adrenaline (A) and noradrenaline (NA) concentrations were measured at rest, immediately after the warm-up and the 6s-sprint and during recovery. Peak power W peak), expressed both in absolute and relative values, were significantly increased in TG in P2 (P<0.01) but did not change in CG. After the sprint-training period, the warm-up and the 6s-sprint induced plasma A increase and the maximal A concentrations were significantly higher than in P1 and P3 for TG only (P<0.05). Plasma A did not change in CG after 6 months. In P3, W peak and maximal lactate concentrations ([La]max) were significantly greater compared to P1 and P2 in TG (P<0.05). In CG, [La]max were significantly increased in P2 (P<0.05). The present study demonstrates that 6 months of sprint training in adolescent girls induce both an increase in performances and in A responses to sprint exercise. This adrenergic adaptation disappears after 5 months of detraining whereas the gain in performance is maintained. These new data may lead to practical considerations.