ACCUMULATED OXYGEN DEFICIT MEASUREMENTS DURING AND AFTER HIGH-INTENSITY EXERCISE IN TRAINED MALE AND FEMALE ADOLESCENTS

The purpose of this study was to compare accumulated oxygen deficits a nd markers of anaerobic metabolism [plasma ammonia (NH3) and lactate ( La-) concentrations] in anaerobically trained male [n = 8, age 14.8 (0 .5) years; maximal oxygen consumption (V) over dot O-2max 61.74 (2.33) ml.kg(-1).min(-1)] and female [n = 8, age 14.5 (0.2) years; (V) over d ot O-2max 49.62 (3.52) ml.kg(-1).min(-1)] adolescents. The exercise pr otocol consisted of runs to exhaustion at speeds predicted to represen t 120% and 130% of (V) over dot O-2max. Arterialised blood samples wer e obtained from a pre-warmed hand via a catheter inserted into a forea rm vein. Samples were taken at rest and after 1, 3, 5, 7, 10, 15 and 2 0 min of recovery. The high-intensity exercise resulted in mean accumu lated oxygen deficits that were less (P < 0.05) in females (52.3 ml.kg (-1)) than in males (68.6 ml.kg(-1)). Lower (P < 0.05) plasma concentr ations of NH3 and La-1, and a higher pH were evident in females compar ed with males during various stages of the 20-min recovery period. The increase in anaerobic performance in the male adolescent athletes whe n compared with their female counterparts was associated with an incre ased plasma concentration of selected plasma and blood metabolites. Th e observed results may reflect well-established differences between th e sexes in the morphology and metabolic power of muscle.