Sodium bicarbonate is a household product commonly known as baking soda that many may be familiar with. What some may not know is that the International Olympic Committee considers sodium bicarbonate to be among the top 5 ergogenic aids to enhance exercise performance in certain sport-specific scenarios. So, which athletes would benefit from its use, how should they take it, and are there any potential side-effects that should be considered?
What does it do?
Sodium bicarbonate supplementation leads to an acute increase in bicarbonate concentration in the blood, making the blood more alkaline. This increases the pH gradient between the muscle and blood leading to an increased transport of hydrogen ions out of the muscle during exercise. This system is also important during exercise, since hydrogen ions can accumulate during high-intensity activity leading to muscle acidosis which can cause muscle fatigue. Thus, more hydrogen ions removed out of the muscle would consequently better maintain the intramuscular pH and minimise the detrimental effect that hydrogen ion accumulation has within the muscle and could lead to an improved exercise performance. Carnosine a buffer we discussed in a previous blog is a buffer inside the muscle that can be increased by ingested beta alanine. Read this blog.
Does it improve exercise performance?
A recent meta-analysis from our group that included 158 original studies showed that, on average, sodium bicarbonate supplementation leads to small beneficial improvements in exercise performance (1). The duration of the exercise bout was a factor that modified the size of this response, with no effects when exercise lasted less than 30 s (too short to be influenced by muscle acidosis). High-intensity exercise lasting anywhere between 30 s and 10 min benefits from sodium bicarbonate supplementation, and this may include tasks such as 200 and 400 m swimming, 4-km time-trial cycling, 2000 m rowing and 800 or 1500 m running. Interestingly, and perhaps surprisingly to some, endurance exercise over 10 min also saw improvements with sodium bicarbonate. It is often thought that endurance exercise is too low in intensity to be influenced by muscle acidosis and, consequently, to benefit from sodium bicarbonate. However, endurance athletes must transiently increase intensity at various moments throughout exercise, such as a sprint finish in cycling, or a final lap sprint in 5,000 and 10,000 m running. These moments of increased intensity are vital to overall performance and may be the moments at which sodium bicarbonate most benefits endurance exercise. Athletes involved in repeated sprint activities, such as team sports, where maximal or near-maximal efforts are performed with short recovery periods are also likely to benefit from using sodium bicarbonate. Considering this, those individuals whose competition event may not last in excess of 30 s (e.g., 100 or 200 m sprint) may still benefit from sodium bicarbonate supplementation during their high-intensity training which likely includes repeated-bout efforts. Overall, sodium bicarbonate can be considered an effective performance enhancing supplement for many athletes.
Overall, sodium bicarbonate can be considered an effective performance enhancing supplement for many athletes.
How much do I need and when should I take it?
Sodium bicarbonate is ingested relative to body mass, with 300 mg/kg body mass (BM) considered to be the optimal dose for enhancing performance (though some studies have shown 200 mg/kg BM to be equally effective). Considering a 70 kg individual would need to ingest 21 g, that is a lot of powder. The supplement can be dissolved in a drink, though palatability is low (salty – try adding some orange-flavoured squash), or ingested in capsules (size 00 capsules can contain 1 g of sodium bicarbonate meaning a total of 21 capsules for 21 g), with both methods of ingestion equally effective. Data from our lab (2) suggests bicarbonate peaks and remains stable for a prolonged period of time, and that supplementation could be initiated between 1 and 3 h prior to when it is needed. Indeed, individual studies have provided sodium bicarbonate anywhere between 1 and 3 h prior to exercise with improvements in subsequent performance.
Data from our lab suggests bicarbonate peaks and remains stable for a prolonged period of time, and that supplementation could be initiated between 1 and 3 h prior to when it is needed.
Are there any side-effects?
Unfortunately, there can be some unwanted side-effects that may occur following sodium bicarbonate ingestion including gastric discomfort, such as bloating and abdominal pain, nausea, vomiting and diarrhoea. The incidence and intensity of these side-effects varies widely between and within individuals. Many athletes may feel that experiencing some side-effects is a small price to pay for potential performance improvements, although caution is advised since some studies do suggest that these side-effects could compromise performance. Luckily, there are some strategies to reduce these uncomfortable symptoms, the most effective being ingesting the supplement alongside a carbohydrate-rich meal. Taking it in capsules give far less problems than a drink and experimenting with different doses and different delivery mechanisms, ingestion with meals, the issues can usually be managed well.
Recommendations for use
Current recommendations for supplementation would be to ingest 200-300 mg/kg BM approximately 1-3 h prior to initiating exercise. The sodium bicarbonate can be dissolved in a drink or taken in capsules, and it is recommended to ingest it alongside a carbohydrate-rich meal to minimise any uncomfortable side-effects.
DE OLIVEIRA, L. F., DOLAN, E., SWINTON, P. A., DURKALEC-MICHALSKI, K., ARTIOLI, G. G., MCNAUGHTON, L. R. & SAUNDERS, B. 2022. Extracellular Buffering Supplements to Improve Exercise Capacity and Performance: A Comprehensive Systematic Review and Meta-analysis. Sports Med, 52, 505-526.
DE OLIVEIRA, L. F., SAUNDERS, B., YAMAGUCHI, G., SWINTON, P. & ARTIOLI, G. G. 2020. Is Individualization of Sodium Bicarbonate Ingestion Based on Time to Peak Necessary? Medicine & Science in Sports & Exercise, 52, 1801-1808.
Interested in this topic? Watch a full lecture by Bryan Saunders and Eimar Dolan on another buffer: beta-alanine.
*Bryan Saunders has previously received sodium bicarbonate supplements at no cost from a national (Farmácia Analítica, Rio de Janeiro, Brazil) and international (Umara AB, Sweden) supplement company for work unrelated to the current article. Farmácia Analítica have not had any input (financial, intellectual or otherwise) into this post or any of the works stemming from studies using their supplements. Sodium bicarbonate supplementation