Sodium bicarbonate, also known as baking soda, has a molecular formula NaHCO3. It is one of those ingredients that is so commonly used in everyday life that it might actually sound not advanced enough to be considered for anything other than cleaning by elite athletes.
However, sodium bicarbonate is one of the most well-researched supplements used in sports and has many times been found to improve performance.
How does it work? When does it work? What are the potential drawbacks? And most importantly, how to use it? These are the questions we will answer in this blog.
How does sodium bicarbonate work?
The molecule of sodium bicarbonate consists of two parts – sodium and bicarbonate. While the sodium part does not really contribute to anything performance-wise and can actually cause gastrointestinal problems (will come to this later), the bicarbonate part plays an important role in the blood.
During very intense exercise (i.e., above FTP or Critical Power) cellular homeostasis is not maintained anymore. There is an accumulation of numerous metabolites, including hydrogen protons (H+). As you may know, an increase in the number/concentration of these protons reduces pH and makes the environment more acidic.
For numerous years it was thought that hydrogen ions are produced together with lactate and form lactic acid. However, this has been highly questioned and probably does not hold true, and it is the breakdown of ATP itself that appears to cause the increase of hydrogen ions.
While there are buffers (a compound that resists changes in pH) within the cells, during intense exercise hydrogen protons must escape the cell, enter the bloodstream, and be removed from there in order to maintain pH within acceptable limits.
Hydrogen protons thus escape the muscle cells together with lactate using monocarboxylate transporters down a concentration gradient. In the bloodstream, bicarbonate reacts with these hydrogen protons and forms water and carbon dioxide if the number of hydrogen protons is too high. We then excrete CO2 with breathing, whereas water is being used for different purposes.
Availability of bicarbonate can be limiting, and hence exogenous (oral) supplementation with it can help maintain a higher (i.e., more normal) pH during exercise.
The next question is whether acidity causes muscle fatigue. And while some argue this is the case, evidence for this is lacking. And indeed, the mechanisms of why bicarbonate supplementation improves exercise performance is not very clear with numerous potential mechanisms, including effects on neural pathways.
When does sodium bicarbonate work?
While the jury is still out there to figure out how and why it works, this does not change the fact that it does work.
So, in what scenarios does it work? Well, in scenarios in which bicarbonate buffering system is being utilized. And this is during very intense workouts – the efforts when you go well above your FTP or Critical Power. In other words, we talk about all-out efforts that are shorter than 15 minutes.
And we can consider it when doing a single effort of this type (e.g., time trial or a short run) or a long cycling race with some sharp climbs in it or an all-out finish. It can also help with training adaptations and for this reason should not be reserved just for competition.
What are the potential drawbacks of sodium bicarbonate?
While the bicarbonate part of sodium bicarbonate will not cause any negative consequences, the sodium part of the molecule can cause some problems.
First, having too much sodium bicarbonate in one single dose can cause gastrointestinal discomfort and lead to diarrhea. The reason for this is that a high intake of sodium can cause water to be drawn from the bloodstream into the intestines (and not the other way around), which leads to unwanted consequences. Yet, with a good ingestion protocol, this can be completely avoided.
Second, loading the body with sodium can cause water retention. This might be unwanted in certain sporting events where an increased body mass presents a bigger disadvantage compared to the advantage presented by an increase in performance.
How to use sodium bicarbonate?
When using sodium bicarbonate, it is important to follow the right ingestion protocol.
First, around 0.3 mg per kg of body mass is required for sodium bicarbonate to be effective.
Second, it takes around 90 minutes for bicarbonate concentrations to reach high enough levels in the bloodstream.
Thus, for shorter events, sodium bicarbonate loading before the exercise is recommended. We advise the following protocol.
Sodium bicarbonate ingestion protocol
