The pH is the negative logarithm of the hydrogen ion concentration. In other words, when the acidity increases, the pH decreases. During high-intensity exercise, energy needs are mainly provided by anaerobic breakdown of glucose and this is associated with a fall in blood and muscle pH (i.e., exercise-induced acidosis). There's evidence that a decrease in pH produces fatigue, defined as a decrease in force production in the presence of increased perception of effort. A buffer is a compound that resists changes in pH, so "buffer loading" (e.g., sodium bicarbonate loading) may delay fatigue during high-intensity exercise.

A recent study by Dr. Douroudos and co-workers examined whether different levels of sodium bicarbonate intake influence performance during high-intensity exercise after five days of supplementation. Twenty-four men were randomly assigned to one of three groups: 1) control (fake supplement), 2) moderate bicarbonate intake (0.3 grams/kilogram/day), and 3) high bicarbonate intake (0.5 grams/kilogram/day). The mean power (i.e., average power output of entire test) was measured before and after a Wingate test, pre- and post-supplementation. The Wingate is a 30-second test performed at a maximal effort against a resistance relative to the subject´s bodyweight, providing an assessment of the ability to maintain high power output over a relatively long duration.

The results indicated that bicarbonate supplementation increases mean power in moderate and high intake groups, with high intake being more effective than moderate intake. Simply put, this study suggests that bicarbonate supplementation improves performance during anaerobic exercise in a dose-dependent manner. Thus, bicarbonate loading may offer some benefits for gym rats who perform very long sets. However, the long-term use of bicarbonate may cause some adverse effects and thus should be avoided.

Reference: Douroudos II et al. Dose-related effects of prolonged NaHCO3 ingestion during high-intensity exercise. Medicine & Science in Sports & Exercise, 38(10):1746-1753, 2006.

 

About the Author

Anssi Manninen holds an M.H.S. in sports medicine from the University of Kuopio Medical School. His cutting-edge articles in Muscular Development firmly established him as a leading authority on hardcore sports nutrition. Anssi´s articles have also been published in scientific journals, including The British Journal of Sports Medicine, The Journal of International Society of Sports Nutrition, Metabolic Syndrome and Related Disorders, Nutrition & Metabolism and Journal of Sports Science and Medicine. Anssi is also an Associate Editor for Nutrition & Metabolism, a leading scientific journal in the area of nutritional biochemistry.