Sodium bicarbonate

What it is

Sodium bicarbonate — ordinary baking soda — acts as a blood buffer. During hard efforts, acidity builds up and contributes to fatigue; raising the blood's buffering capacity can delay that, helping you sustain high-intensity work a little longer.

What the evidence shows

Repeated high-intensity exercise. Well-supported· human data There is solid evidence it can improve performance in efforts lasting roughly one to ten minutes — the kind of sustained, painful, high-intensity work where acidity is a limiter.

Single maximal lifts and long steady endurance. Marketing claim Its benefit is specific to that high-intensity window, not to one-rep-max strength or to long, low-intensity endurance.

Who it suits

Athletes in events with repeated or sustained high-intensity efforts — middle- distance running, rowing, swimming, combat sports and similar — who tolerate it.

Practical notes

The catch is the gut: meaningful amounts commonly cause bloating, cramps and diarrhoea, which can wreck a session. It must be trialled thoroughly in training before ever being used in competition, never first on race day. It is also a large sodium load, so it doesn't suit everyone. Some evidence suggests it can complement beta-alanine, which buffers acidity from inside the muscle cell.

Sources

PubMed: sodium bicarbonate supplementation and high-intensity exercise performance (position stands and trials)

Frequently asked questions

What does sodium bicarbonate do?

It raises the blood's buffering capacity, helping neutralise the acidity that builds up during hard efforts. There's solid evidence it can improve performance in repeated high-intensity exercise lasting roughly one to ten minutes.

What's the catch?

The gut. Meaningful doses commonly cause bloating, cramps and diarrhoea, which can easily outweigh the benefit. This is the single biggest reason people abandon it, and why it must be tested thoroughly in training first.

How does it compare to beta-alanine?

They buffer acidity by different routes — bicarbonate outside the muscle cell, beta-alanine (via carnosine) inside it — and some evidence suggests they can complement each other for the right kind of high-intensity event.