Influence of sodium bicarbonate on sprint performance: relationship to dosage.

The purpose of this investigation was to determine the minimum oral dosage of bicarbonate needed to significantly elevate blood bicarbonate and the influence of induced alkalosis on performance in high-intensity, short-duration exercise. Nine endurance-trained cyclists performed four 2-min sprints on separate occasions using an isokinetic cycle ergometer (Fitron, Cybex, Inc.). One hour before each test, the cyclists consumed either a placebo (A), a solution of 0.10 g NaHCO3.kg-1 body weight (B), a solution of 0.15 g NaHCO3.kg-1 body weight (C), or a solution of 0.20 g NaHCO3.kg-1 body weight (D) in random order. Arterialized venous blood was taken before (PRE) and after (POST) ingestion, and 1, 3, 5, 10, and 15 min following the 2-min bike sprint. The results showed a significant increase in POST blood bicarbonate, and the elevation was incrementally related to the dosage. There was, however, no significant improvement in performance. Total work (mean +/- SE) for each treatment (N.m per 2 min) were: A, 47,267 (+/- 2,472); B, 47,004 (+/- 3,094); C, 46,312 (+/- 2,964); and D, 47,190 (+/- 2,621). The results of this study show that incremental doses of NaHCO3 of 0.20 g.kg-1 and below produce incremental elevations in blood bicarbonate but do not produce improvements in performance for a sprint bout lasting 2 min.