Effects of Caffeine, Sodium Bicarbonate, and Their Combined Ingestion on High-Intensity Cycling Performance
This double-blind crossover study investigated the effect of caffeine and sodium bicarbonate on time trial performance. The investigators enrolled 10 well-trained cyclists to perform 3-km time trials. The participants were given weight-based dosing of caffeine alone, sodium bicarbonate alone, a combination of the 2, or placebo for each trial. The main outcome measures were performance times, power output, and blood sample analysis of pH, lactate, and bicarbonate.
All 3 test groups (caffeine, sodium bicarbonate, and a combination) had a higher mean power output and faster performance times when compared with placebo trials. Performance times were approximately 1% faster for each test group (P < .05); however, there was no additive effect of caffeine and sodium bicarbonate in the trials. Blood pH decreased substantially, and lactate rose across all treatments, with no significant difference among groups.
Although the investigators note a performance enhancement with both caffeine and sodium bicarbonate, it is still unclear which supplement is responsible for enhanced performance. The authors conclude that dual supplementation with caffeine and sodium bicarbonate does not further augment performance for short-duration, high-intensity exercise. Limitations of the study include small sample size, using only 2 supplements, and performing a short-duration exercise trial.
(Int J Sport Nutr Exerc Metab. 2012;22(3):175–183). AE Kilding, C Overton, J Gleave
Prepared by Matthew Stewart, MD, University of Utah Emergency Medicine Resident, Salt Lake City, UT, USA