Abstract

The effects of alkalosis on submaximal and maximal exercise performance of a relatively long duration have been investigated previously. The present study examined the effects of sodium bicarbonate ingestion on cycling performance of the 30 s Wingate Anaerobic Test using 13 male physical education students. Three hours prior to exercise, subjects ingested either table salt (control) or sodium bicarbonate (alkalosis) of equimolar dosage (10 and 13 g, respectively) in capsule form. Biopsies were taken from the m. vastus lateralis for determination of muscle fibre composition. Resting blood pH was 7.43 +/- 0.01 (mean +/- S.E.) for the alkaline condition versus 7.37 +/- 0.01 for the control condition. Mean power output increased significantly following treatment. Peak power output was not affected. No relationship was found between fibre type distribution and sensitivity to the alkaline treatment. The increased alkali reserve reduced mean post-exercise acidosis by 0.05 pH units. This study demonstrates that changes in pre-exercise blood pH values have significant, though relatively minor, effects on anaerobic exercise capacity, but none on peak anaerobic power, as determined by the Wingate Anaerobic Test. Verf.-Referat