Bicarbonate ingestion has no ergogenic effect on consecutive all out sprint tests in BMX elite cyclists.

摘要

The aim of the present study was to examine the effect of sodium bicarbonate ingestion on consecutive "all out" sprint tests, analyzing the acid-base status and its influence on performance and perceived effort. Ten elite bicycle motocross (BMX) riders (20.7 +/- 1.4 years, training experience 8-12 years) participated in this study which consisted of two trials. Each trial consisted of three consecutive Wingate tests (WTs) separated by 15 min recovery. Ninety minutes prior to exercise subjects ingested either NaHCO(3) (-) (0.3 g kg(-1) body weight) or placebo. Blood samples were collected for the assessment of blood acid-base status: bicarbonate concentration ([HCO(3) (-)]), pH, base excess (BE) and blood lactate concentration ([La(-)]). Performance variables of peak power (PP), mean power (MP), time to peak power and fatigue index were calculated for each sprint. Significant differences (p < 0.05) were observed in acid-base variables [pH before WT1: 7.47 +/- 0.05 vs. 7.41 +/- 0.03; [HCO(3) (-)] before WT1: 29.08 +/- 2.27 vs. 22.85 +/- 0.24 mmol L(-1) (bicarbonate vs. placebo conditions, respectively)], but there were not significant differences in performance variables between trials [PP WT1: 1,610 +/- 373 vs. 1,599 +/- 370 W; PP WT2: 1,548 +/- 460 vs. 1,570 +/- 428 W; PP WT3: 1,463 +/- 361 vs. 1,519 +/- 364 W. MP WT1: 809 +/- 113 vs. 812 +/- 108 W; MP WT2: 799 +/- 135 vs. 799 +/- 124 W; MP WT3: 762 +/- 165 vs. 782 +/- 118 W (bicarbonate vs. placebo conditions, respectively)]. Rating of perceived effort (RPE) was not influenced nor ratings of perceived readiness. Sodium bicarbonate ingestion modified significantly the blood acid-base balance, although the induced alkalosis did not improve the Wingate test performance, RPE and perceived readiness across three consecutive WTs in elite BMX cyclists.