Are there any concerns or considerations?
- The major side effect associated with sodium bicarbonate supplementation is gastrointestinal distress, with symptoms including nausea, stomach pain, diarrhoea and vomiting. This is a serious practical consideration for athletes in a competition setting, and this may counteract the potential performance benefits from enhanced buffering.
- Research undertaken at the AIS systematically studied a series of sodium bicarbonate supplementation protocols, varying the time taken to consume the load (spreading it over 30 to 60 mins), the form of the delivery (flavoured powder or capsules) and the consumption of various amounts of fluid or food with the sodium bicarbonate.4 Of the protocols tested, the best strategy to optimise blood bicarbonate levels and to reduce the occurrence of GI symptoms was to consume capsules in a spread-out protocol, commencing 120 to 150 min before the start of exercise and, if practical, at the same time as consuming a meal composed of carbohydrate-rich food choices and some fluid.
- It is generally advised to ingest sodium bicarbonate capsules or dissolvable powder with sufficient fluid to decrease the risk of hyperosmotic diarrhea (~ 10ml/kg BM).
- Given the significant amount of fluid intake recommended to alleviate GI distress, consideration may be given toward the additional weight gain this might induce for weight-dependent sports.
- Repeated use of acute loading protocols (e.g. heats and finals in a single or multi-day competition) may require individualized attention to exacerbate the risk of side-effects. This may be reduced if the athlete uses lower doses on subsequent occasions to compensate for bicarbonate remaining in the body.
- Anecdotal feedback from athletes also suggests that those unfamiliar with sodium bicarbonate supplementation may need to experience the supplement on a number of occasions prior to competition, due to the potential for impaired perceptive feedback from the working muscles.
- Changes in urinary pH are expected following bicarbonate supplementation. If an athlete is selected for a drug test, they may need to wait several hours before urinary pH returns to the levels that are acceptable to drug testing authorities. This may cause some disruption to the athlete’s routine.