Sodium bicarbonate improves sprint performance in endurance cycling.

OBJECTIVES

Oral sodium bicarbonate intake (NaHCO3) may improve performance in short maximal exercise by inducing metabolic alkalosis. However, it remains unknown whether NaHCO3 also enhances all-out performance at the end of an endurance competition. Therefore, the present study investigated the effect of stacked NaHCO3 loading on sprint performance following a 3-h simulated cycling race.

DESIGN

Double-blind randomized placebo-controlled cross-over study.

METHODS

Eleven trained male cyclists (22.3 (18.3-25.3) year; 73.0 (61.5-88) kg; VO2max: 63.7 (57-72) mlkg-1min-1) ingested either 300mgkg-1 body weight NaHCO3 (BIC) or NaCl (PL). NaHCO3 or NaCl was supplemented prior to (150mgkg-1) and during (150mgkg-1) a 3-h simulated cycling race with a 90-s all-out sprint (90S) at the end. Capillary blood samples were collected for determination of blood pH, lactate and HCO3- concentrations. Analysis of variance (lactate, pH, HCO3-) and paired t-test (power) were applied to compare variables across condition (and time).

RESULTS

NaHCO3 intake improved mean power during 90S by ∼3% (541±59W vs. 524±57W in PL, p=0.047, Cohen's D=0.28, medium). Peak blood lactate concentration and heart rate at the end of 90S were higher (p<0.05) in BIC (16.2±4.1mmoll1, 184±7bpm) than in PL (12.4±4.2mmoll-1, 181±5bpm). NaHCO3 ingestion increased blood [HCO3-] (31.5±1.3 vs. 24.4±1.5mmoll-1 in PL, p<0.001) and blood pH (7.50±0.01 vs. 7.41±0.03 in PL, p<0.05) prior to 90S.

CONCLUSIONS

NaHCO3 supplementation prior and during endurance exercise improves short all-out exercise performance at the end of the event. Therefore, sodium bicarbonate intake can be applied as a strategy to increase success rate in endurance competitions.