Effect of expertise on post maximal long sprint blood metabolite responses Maximal running exercise and acid-base status in elite versus regional athletes
Résumé
The aim of this study was to describe and compare the blood metabolic responses obtained after a single maximal exercise in elite and less-successful athletes, and to investigate whether these responses are related to sprint performance. Eleven elite (ELI) and fourteen regional (REG) long sprint runners performed a 300-m running test as fast as possible. Blood samples were taken at rest and at 4 min after exercise for measurements of blood lactate [La] and acid-base status. The blood metabolic responses of ELI compared to REG subjects for pH (7.07 + 0.05 versus 7.14 + 1.5), sodium bicarbonate concentration [HCO3-] (8.1 + 1.5 versus 9.8 + 1.8 mmol.L-1), haemoglobin O2 saturation (SaO2) (94.7 + 1.8 versus 96.2 + 1.6 %) were significantly lower (P < 0.05) and blood lactate concentration [La] was significantly higher in ELI (21.1 + 2.9 versus 19.1 + 1.2 mmol.l-1, P < 0.05). The 300-m performance (in % world record) was negatively correlated with pH (r=-0.55, P < 0.01), SaO2 (r=-0.64, P < 0.001), [HCO3-] (r=-0.40, P < 0.05), and positively correlated with [La] (r=0.44 P < 0.05). In conclusion, for a same quantity of work, the best athletes are able to strongly alter their blood acid-base balance compared to underperforming runners, with larger acidosis and lactate accumulation. To obtain the pH limits with acute maximal exercise, coaches must have their athletes perform a distance run with duration of exercise superior to 35 s. The blood lactate accumulation values (mmol.L-1.s-1) recorded in this study indicate that the maximal glycolysis rate obtained in the literature from short sprint distances is maintained, but not increased, until 35 s of exercise.
Domaines
Physiologie du sport
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