You might know sodium bicarbonate as the stuff sitting in the back of your kitchen cupboard. But did you know it’s also one of the more well-researched performance supplements in sport?
From 5K runners and track athletes to marathoners, cyclists and HYROX competitors, sodium bicarbonate is used by athletes looking to support performance when the intensity starts to rise.
But what does it actually do? When should runners use it? And where does FLYCARB fit into the picture?
Let’s break it down.
First things first: what is sodium bicarbonate?
Sodium bicarbonate (NaHCO₃) is an alkaline compound that your body naturally uses as part of its acid-base buffering system.
When you exercise at high intensity, your muscles produce hydrogen ions as part of the energy-producing processes involved in hard exercise. As the concentration of these ions increases, muscle acidity rises.
Your body has its own buffering systems to help manage this change. One of those systems involves bicarbonate in your blood.
Taking sodium bicarbonate increases the amount of bicarbonate available in the blood, increasing extracellular buffering capacity. The theory is that this can help your body deal with the increased acidity associated with intense exercise and potentially allow you to sustain a high intensity for longer.
And importantly, this isn't about simply "getting rid of lactic acid". The physiology is a little more complicated than that.
So, can bicarbonate actually improve performance?
There is good evidence that sodium bicarbonate can improve performance in certain types of high-intensity exercise, although the effect isn't the same for everyone or every type of running.
Research has found benefits particularly in high-intensity and intermittent exercise, including efforts where you're working hard for relatively short periods or repeatedly pushing the intensity.
However, it's not a case of taking bicarbonate and automatically running faster.
A recent systematic review looking specifically at continuous running found little overall benefit from a single dose across the studies included. This highlights an important point: bicarbonate appears to be more useful when the demands of the event involve a significant high-intensity component, rather than being viewed as a universal running supplement.
So, where could it fit into a runner's training?
When could runners use sodium bicarbonate?
🏃 Interval sessions
Think 400m, 800m or 1K reps, hill repeats or other sessions where you're repeatedly running hard.
These are exactly the types of sessions where you're asking your body to produce a lot of energy at a high intensity, making them a useful opportunity to experiment with bicarbonate.
⚡ Threshold and tempo sessions
Hard sustained efforts can also be an opportunity to trial it.
If you're working around your threshold pace, practising your nutrition strategy during training can help you understand whether bicarbonate works well for you before using it in competition.
🏁 5K and 10K racing
Shorter races can involve a sustained high intensity from start to finish, with plenty of anaerobic contribution — particularly as you push towards the finish.
This is one reason sodium bicarbonate has become popular among athletes competing over shorter distances.
🧱 HYROX and hybrid events
Bicarbonate isn't just for runners.
HYROX combines running with repeated high-intensity functional stations, meaning you're constantly switching between hard running and demanding exercises.
For athletes competing in HYROX or other hybrid events, bicarbonate is therefore an interesting area to explore as part of a wider race-fuelling strategy.
🏃 Longer races
This is where things get a little more nuanced.
For a marathon or longer endurance event, carbohydrate, hydration and electrolytes remain the foundations of your race nutrition.
Bicarbonate isn't a replacement for any of these.
However, some athletes choose to use it as part of their strategy, particularly where the race involves sustained intensity or a hard finish. The evidence isn't as straightforward for continuous endurance running, so it's something to trial rather than automatically add to your race plan.
How much sodium bicarbonate do you need?
This is where you shouldn't simply grab a box of bicarbonate of soda from the kitchen cupboard!
Research into sodium bicarbonate supplementation commonly uses doses based on body weight. The International Society of Sports Nutrition notes that around 0.2 g/kg may be the minimum dose associated with an ergogenic effect, with approximately 0.3 g/kg often used as an effective single dose. Higher doses don't necessarily mean better results and can increase the likelihood of side effects.
And that's one of the biggest considerations with bicarbonate...
The not-so-fun bit: your stomach
Sodium bicarbonate can cause gastrointestinal side effects including bloating, nausea, stomach pain and diarrhoea. This is one of the reasons it's so important to experiment with it in training rather than making race day your first attempt.
Your individual response matters too.
Two runners can take the same dose and have completely different experiences.
That's why the goal isn't simply to take as much bicarbonate as possible. It's to find a dose and timing that you can tolerate and that fits your event.
So, where does FLYCARB come in?
This is where FLYCARB has taken the science behind sodium bicarbonate and made it much more practical for athletes.
Rather than measuring out bicarbonate powder yourself, FLYCARB's BICARRB is specifically formulated as a pre-event sports nutrition product.
Each serving contains an Energy Mix and a Bicarb Mix, designed to deliver a high dose of sodium bicarbonate in a format that's straightforward to prepare and consume.
There are several BICARRB options available, including Original BICARRB, Mango BICARRB and Mint BICARRB, as well as caffeinated options such as CAFCarb.
When should you take FLYCARB BICARRB?
For most high-intensity events, FLYCARB recommends taking BICARRB around 2 hours before the start. For events lasting around 90 minutes to 3 hours, FLYCARB suggests approximately 75–90 minutes before the start.
The exact timing can depend on the event, your individual response and the strategy you're using.
That's another reason to practise before race day.
Your first BICARRB trial shouldn't be on race morning.
Instead, choose a hard training session and test:
- Your portion size
- Your timing
- How your stomach responds
- How it fits around your normal pre-run meal
- How you feel during the session
FLYCARB has a BICARRB calculator which takes your body weight and experience level into account when recommending a portion. For newer users, it recommends starting with a lower dose before progressing towards an optimal performance dose.
What about your normal fuelling?
This is really important.
BICARRB isn't a carbohydrate gel.
It's doing a different job.
If you're heading out for a long run or racing a marathon, you still need to think about carbohydrate intake, hydration and electrolytes.
FLYCARB recommends eating your normal pre-event meal and, as part of its BICARRB protocol, suggests a carbohydrate snack such as toast or a banana around 30 minutes before taking BICARRB. It also recommends avoiding other nutrition for 20 minutes before and after taking it, while water or HICARB can still be sipped.
Think of bicarbonate as one part of your performance nutrition strategy, not the entire strategy.
How to use BICARRB in your training
Here's a simple example.
You're training for a 10K PB.
You've got a session of 6 x 1K at around 10K pace coming up.
Instead of waiting until race day, you could use this session as your BICARRB trial.
Before the session
Eat your normal pre-run meal.
Follow the recommended BICARRB portion for your body weight and experience level.
Take it at the appropriate time before your session.
During the session
Pay attention to how you feel.
Can you maintain your target pace?
How does your stomach feel?
Does anything feel different compared with your normal sessions?
Afterwards
Make a note of what you did.
If it worked well, you've now got useful information to take into your race preparation.
If your stomach didn't agree with it, you've also learned something — and you've learned it during training rather than halfway through your 10K!
Who might benefit from trying it?
Bicarbonate is particularly interesting for runners who regularly train or compete at high intensity.
That could mean:
5K runners looking to sustain a hard pace.
10K runners who want to experiment with another performance strategy.
Track athletes completing repeated high-intensity efforts.
HYROX athletes dealing with repeated running and functional stations.
Hybrid athletes combining running with strength or conditioning.
It isn't something every runner needs, and it shouldn't replace the fundamentals of good training and fuelling.
But for athletes who have those foundations in place, bicarbonate is an interesting performance tool to experiment with.
The Running Bear takeaway
Sodium bicarbonate isn't a magic powder that will suddenly knock minutes off your PB.
What it can do is support one specific part of exercise physiology: your body's ability to buffer the increased acidity associated with hard exercise.
The evidence is strongest for high-intensity exercise, and individual responses vary.
The biggest takeaway?
Don't wait until race day to experiment.
Try it during training. Find the portion and timing that work for you. See how your body responds. Then, if it fits your strategy, you can take that experience into race day.
And if you want to try bicarbonate without having to measure and mix your own, FLYCARB BICARRB is now available at Running Bear.
Speak to the Running Bear team if you're not sure which option is right for you — and remember that FLYCARB products contain a high amount of sodium, so follow the recommended portion and hydration guidance. FLYCARB recommends a maximum of three BICARRB uses per week.