Effects of sodium bicarbonate ingestion on prolonged intermittent exercise.
OBJECTIVE
The aim of this study was to determine the effects of sodium bicarbonate ingestion on prolonged intermittent exercise and performance.


METHODS
Eight healthy male subjects (mean +/- SD: age 25.4 +/- 6.4 yr, mass 70.9 +/- 5.1 kg, height 179 +/- 7 cm, VO(2max) 4.21 +/- 0.51 L.min-1) volunteered for the study, which had received ethical approval. Subjects undertook two 30-min intermittent cycling trials (repeated 3-min blocks; 90 s at 40% VO(2max), 60 s at 60% VO(2max), 14-s maximal sprint, 16-s rest) after ingestion of either sodium bicarbonate (NaHCO(3); 0.3 g.kg-1) or sodium chloride (NaCl; 0.045 g x kg(-1). Expired air, blood lactate (BLa), bicarbonate (HCO(3)-), and pH were measured at rest, 30 and 60 min postingestion, and during the 40% VO(2max) component of exercise (4, 10, 16, and 29 min).


RESULTS
After ingestion, pH increased from rest to 7.46 +/- 0.03 and 7.40 +/- 0.01 for NaHCO(3) and NaCl, respectively (main effect for time and trial; P < 0.05). Values decreased at 15 min of exercise to 7.30 +/- 0.07 and 7.21 +/- 0.06, respectively, remaining at similar levels until the end of exercise. BLa peaked at 15 min (12.03 +/- 4.31 and 10.00 +/- 2.58 mmol.L-1, for NaHCO(3) and NaCl, respectively; P > 0.05) remaining elevated until the end of exercise (P < 0.05). Peak power expressed relative to sprint 1 demonstrated a significant main effect between trials (P < 0.05). Sprint 2 increased by 11.5 +/- 5% and 1.8 +/- 9.5% for NaHCO(3) and NaCl, respectively. During NaHCO(3), sprint 8 remained similar to sprint 1 (0.2 +/- 17%), whereas a decrease was observed during NaCl (-10.0 +/- 16.0%).


CONCLUSIONS
The results of this study suggest that ingestion of NaHCO(3) improves sprint performance during prolonged intermittent cycling.
Price
Mike
M
School of Science and the Environment, Coventry University, Coventry, United Kingdom. m.price@coventry.ac.uk
Moss
Paul
P
Rance
Stuart
S
D000284:Administration, Oral; D000328:Adult; D015444:Exercise / Q000502:physiology*; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D019344:Lactic Acid / Q000097:blood; D008297:Male; D018482:Muscle, Skeletal / Q000187:drug effects; D010101:Oxygen Consumption / Q000187:drug effects; D010807:Physical Endurance / Q000187:drug effects*; D005082:Physical Exertion / Q000187:drug effects; D012146:Rest / Q000502:physiology; D017693:Sodium Bicarbonate / Q000008:administration & dosage*; D012965:Sodium Chloride / Q000008:administration & dosage; D013647:Task Performance and Analysis
D019344:Lactic Acid; D012965:Sodium Chloride; D017693:Sodium Bicarbonate