Bicarb shown to improve 10km performance

Bicarb shown to improve 10km performance

Sodium bicarbonate (bicarb) is classically associated with short, high-intensity efforts, but anyone who’s used it over longer distances notices the difference!

Whilst there are some really promising endurance cycling studies on the impact of bicarb, showing around a 1.4% performance gain, there haven’t been any specific running studies. 

Until now! A new research project has shown the benefits of bicarb extend to endurance running. The research looked at 21 recreational female runners completing a 10km time trial. 

The participants were an average of 32 seconds faster after taking bicarbonate!

Crucially, these performance tests took place on an outdoor athletics track, providing evidence in a setting more closely related to racing than a laboratory test.

So what did the researchers test?

Twenty-one recreational female runners completed two 10km track time trials: one after taking bicarb and another after taking a placebo. The study used a randomised, double-blind, crossover design. That's a big tick for credibility! 

Participants took 0.3g of sodium bicarbonate per kilogram of body mass (as we recommend via our calculator),  alongside a carbohydrate-rich meal approximately 90 minutes before running. The placebo trial included the same carbohydrate intake, and both tests took place during the same phase of each runner’s menstrual cycle.

What were the key findings?

• Faster with bicarb 10 km times: 32 seconds (1.05%)
• Higher blood bicarbonate and pH before the test and remained elevated after. This shows there was an increase in the body’s extracellular buffering capacity.
• No difference between placebo and bicarb for gastrointestinal symptoms.

Why does this matter for endurance athletes?

A 10 km race is predominantly aerobic, but maintaining a hard pace still requires the body to work partly anaerobically. This creates acidic conditions in the muscles (think burning legs!).

Bicarb acts to increase your acidity buffering capacity, helping support the movement of hydrogen ions out of working muscles. This study shows that bicarb buffering can translate into a measurable performance over 10km.

Finally, it’s great to have more female-specific evidence in a research area in which women have historically been underrepresented! A big tick from us!

Source: Aktitiz et al. (2026), “Acute Sodium Bicarbonate Supplementation Enhances 10-km Outdoor Track Running Performance in Recreational Female Runners.” International Journal of Sport Nutrition and Exercise Metabolism. DOI: 10.1123/ijsnem.2026-0041.