You probably think of sodium bicarbonate or bicarb soda as that ingredient you have stashed at the back of your cupboard waiting for you to bake some muffins.
But bicarb isn’t just an ingredient for tasty baked goods, it is also a substance that can be used to improve athletic performance and is even produced by our own bodies.
Bicarbonate has an important role in preventing the buildup of acid.
One of the largest producers of bicarbonate in the human body is actually the stomach. When we eat, our body rushes to produce as much stomach acid and digestive juice as required for breaking down and digesting that food.
In the process, bicarbonate is produced. Unfortunately, this bicarbonate does not improve athletic performance but interestingly enough, it may be one of the reasons we get sleepy after a large meal. This is known as the alkaline tide.
How Can Bicarbonate Assist With Sports Performance?
When we partake in intense exercise, lactate and hydrogen ions are produced in the muscles. The build-up of these products is thought to result in the sensation of muscle ‘burning’ and general muscle fatigue.
However, increasing the bicarbonate concentration in the muscle’s extracellular space, can increase the buffering of hydrogen ions and prevent or slow the acid buildup.
Due to a slower build of hydrogen ions and acidity, muscle fatigue can be delayed allowing the athlete or exerciser to perform better for longer.
Bicarbonate ingestion could theoretically enhance performance in exercise that involves sustained high-intensity exercise lasting between 1 to 8 minutes.
These sports are going to rely heavily on anaerobic glycolysis for energy production and are therefore going to result in a buildup of hydrogen ions.
This could include swimming, CrossFit, running, track cycling, rowing, higher repetition strength training, combat sports, and stop-and-go sports like football.
Furthermore, bicarb could also be useful for longer periods of intense exercise lasting 30-60 minutes by allowing a delay in muscular fatigue and enabling the athletes to produce more power for short periods of time during the event.
What Does The Research Say?
For over 80 years, research has been done on the effects of ingesting bicarbonate on athletic performance.
In 1931, researchers showed that ingesting a solution of baking soda before exercise could improve running performance. Nonetheless, since then, this field of research has culminated in a lot of mixed results.
A systematic review published in 2019 found seventeen of the 35 included studies showed performance-enhancing effects after supplementing with bicarb soda. That leaves 18 studies that didn’t show any improvement in performance.
A 2006 study by Berger et al. found after bicarbonate ingestion there was a significantly lower oxygen cost of exercise after 6 minutes of constant work-rate exercise at an intensity of 80% of VO2 max. A reduction in oxygen cost would likely result in improvements in exercise tolerance and performance.
Another study by Bishop et al. (2004) found a 5% increase in total work done during five 6 second sprints separated by a 30 second recovery period. This research is very relevant to those stop-and-go sports where there are short periods of high-intensity activity throughout.
However, Parry-billings et al. (1986) found no performance benefit from bicarb ingestion in repeated 30-second sprints.
But although research shows very mixed results, the 2018 Olympic Committee Sports Nutrition Consensus Statement recommendations suggest that sodium bicarbonate is one of five dietary supplements that consistently improves performance in elite athletes.
How Do You Use Bicarbonate?
Current ingestion recommendations for bicarb soda are to consume between 200 to 400 mg/kg of body weight with a small, carbohydrate-dense meal (~1.5 g/kg body weight of carbs) 2-2.5 hours prior to exercise.
This recommendation comes from the Australian Institute of Sport (AIS). However, they also recommend that this is just a general guide and that supplementation and dosage should be individualized to each person.
Dosage may differ depending on tolerability and susceptibility to gastrointestinal distress. For some athletes, it may be required to take a smaller dose to prevent gut issues.
There is also a matter of timing. Commencing exercise at an individual’s peak blood buffering capacity may be more likely to improve performance. Although, timing the ingestion of bicarb in this way would take practice and testing blood bicarbonate levels to see how long it takes before they peak for each individual. This is not going to be feasible for everyone.
If individualizing the ingestion strategy is not feasible, ingestion at the higher end of the recommended doses (e.g. 300 to 400 mg/kg) 2 to 3 hours pre-competition is recommended.
This will significantly elevate blood buffering capacity to levels presumed to be ergogenic (~ 5 – 6 mmol/L increase) with effects lasting for 3-4 hours.
Co-ingestion with a small, carb-rich meal is suggested because it could offset potential issues with gastrointestinal distress and supports blood alkalosis.
This recommendation for carbohydrate intake is also in line with pre-exercise recommendations for general performance in many sports and training styles.
For an athlete who is competing several times over the course of a day, they may choose to use a top-up method. Although not verified by research yet, the AIS states that you can take smaller doses (~100mg) of bicarb throughout the day to keep levels elevated.
Alternatively, a bicarbonate supplementation protocol involving multiple divided doses over several days before competition may be used. This could look like 500mg/kg body weight of bicarb split into several even doses for up to five days including the day of competition (e.g. 100mg/ kg body weight with 3 main meals and 2 snacks).
What Forms Can Bicarbonate Be Supplemented In?
Bicarb soda can be taken in a couple of forms.
The most economical is just plain old bicarb soda from the grocery store. Although many athletes find that this is difficult to consume due to its unpleasant taste.
You can also purchase bicarb in capsules or put bicarb into capsules yourself to make it easier to ingest. It has been proposed that the capsules can resist digestion and won’t break down until reaching the intestines which may actually also reduce the risk of gastrointestinal distress.
However, capsules usually only fit 1-3g worth of product in them. If you think about the suggested serving size for a 75kg athlete (15-30g of bicarb), that is A LOT of capsules.
Unfortunately, the most feasible way to get the recommended dosage of bicarb is likely by mixing regular bicarb soda with water and potentially some flavour to mask the taste.
Are There Any Side-Effects?
As discussed a couple of times, the major potential side effect of bicarb soda ingestion in such large quantities is gastrointestinal distress. This could include stomach pain, nausea, vomiting, and diarrhea.
The best strategy to increase blood alkalosis and to reduce GI symptoms may be to spread out the consumption of bicarbonate, commencing 120-150 min before the start of exercise, and consuming it alongside a small carbohydrate-based meal and some fluid. It is recommended that athletes wishing to use bicarbonate experiments to find which loading protocol suits them best (i.e., optimizes performance while minimizing GI disturbance).
Another potential side effect is some temporary fluid retention. Sodium bicarbonate does include sodium and consumed in such large quantities could lead to some fluid retention.
This actually could be useful for some sports where high sweat losses are likely and/or when access to fluids will be minimal.
Otherwise, for some sports, the increase in body weight may be a disadvantage. It should definitely be a consideration in a weight-making sport prior to weigh-in.
Other Considerations When Using Sodium Bicarbonate
It is generally advised to ingest sodium bicarbonate with sufficient fluid to decrease the risk of hyperosmotic diarrhea. Having 10ml/kg body weight of fluid with bicarb would likely be enough to offset this.
Anecdotal feedback from athletes also suggests that those unfamiliar with using bicarbonate supplementation may need to experience the effects in training on several occasions before using it in competition. This is due to the change in perceived feedback from working muscles.
Nonetheless, it is a good idea to test a supplement like this many times in training anyway to personalize dosage, timing and ensure that gut issues do not occur or are somewhat manageable.
- Bicarbonate supplementation may be useful in high intensity exercise lasting 1-8 minutes and longer lasting sports with short periods of high intensity efforts.
- The exact psychological mechanisms of bicarb supplementation are unknown but it likely has something to do with bicarb’s ability to minimise or slow the buildup of hydrogen ions and lactic acid in the muscles.
- Current ingestion recommendations for bicarb soda are to consume between 200 to 400 mg/kg of body weight with a small, carbohydrate dense meal (~1.5 g/kg body weight of carbs) AND 10ml/kg of fluids, 2-3 hours prior to exercise. Although dosages and timing should be practiced in training and individualised to the athlete.
- Sodium bicarbonate supplementation may cause gastrointestinal distress and/or water retention.