Bicarbonate During Exercise: What a New Study on Bicarb GEL 40 Reveals

Races are rarely decided in the first hour. The decisive surge, the final climb, the finish after 150 kilometers: precisely when your legs are already tired, every watt of reserve counts. A new study from Liverpool John Moores University now shows for the first time that bicarbonate, taken in gel form during exercise, can help precisely during this phase. In this article, we explain what bicarbonate does in the body, how it has been used so far, and what the new study found using our BICARB GEL 40.

Bicarbonate: The Body’s Natural Acid Buffer

Bicarbonate (HCO₃⁻) is not a foreign substance, but a key component of your blood. It is part of the most important buffer system outside the cells and keeps your blood’s pH within a narrow range around 7.4. At rest, the bicarbonate concentration in the blood is about 24 mmol/L.

During high-intensity exercise, your muscles derive a large portion of their energy from anaerobic glycolysis (the breakdown of carbohydrates without oxygen). This process produces lactate and hydrogen ions (H⁺). The hydrogen ions lower the pH level in the muscle cells. This acidification disrupts enzyme function and muscle contraction and contributes to fatigue.

The body therefore transports H⁺ and lactate out of the muscle cells and into the blood. There, bicarbonate binds the hydrogen ions. The result: carbon dioxide and water—you simply exhale the CO₂. The more bicarbonate available in the blood, the easier it is to remove these substances from the muscle.

More Buffer Through External Intake: The Classic Loading Method

Sodium bicarbonate is one of the most extensively studied supplements in sports. The idea is that when you consume additional bicarbonate, its concentration in the blood rises—typically by 4 to 8 mmol/L at a dose of 0.2 to 0.4 g per kg of body weight. The larger “buffer tank” makes it easier for the muscles to get rid of acid and can delay fatigue during intense exercise. This has been well documented for maximum efforts lasting about 30 seconds to 60 minutes.

Almost all research to date is based on taking it before exercise: as a single dose 20 to 180 minutes before the start, as a loading regimen lasting several days, or individually tailored to the time when the bicarbonate level in the blood peaks.

Important: Loading always takes place before exercise. Ideally, you should divide the total dose into two phases: 60% about three hours before exercise, and the remaining 40% one hour before. We recommend taking the first dose with your last meal. It’s best to take the second dose with water or one of our drink mixes, as this improves tolerability.

This approach has its limitations. The timing varies from person to person and can differ significantly: Depending on the individual, peak levels are reached after about 60 to 180 minutes. In long races, the decisive phase often doesn’t occur until hours after the start—well beyond the optimal window. And the traditional forms are hardly suitable for consumption on the go: solutions taste unpleasant, and a 75-kg athlete would have to swallow 20 to 25 large capsules. On top of that, there’s the risk of gastrointestinal discomfort.

The New Approach: Bicarbonate During Exercise

With BICARB GEL 40, we’ve made bicarbonate available in a format that endurance athletes already use on the go: the GEL 40. Each gel contains 5 g of bicarbonate (4,500 mg of sodium bicarbonate and 500 mg of potassium bicarbonate) plus 40 g of carbohydrates in a glucose-to-fructose ratio of 1:0.8. The bicarbonate is encapsulated so that it is released only in the small intestine and not in the stomach. This is intended to make it easier to tolerate.

This allows for two possible strategies:

• Top-up: You load as usual before the start and maintain your bicarbonate levels during the race with the gel. This remains our primary recommendation to this day.
• Gel-Only-Protocol: You skip the loading phase and consume the bicarbonate exclusively via the gel during exercise.

For the first time, there is now scientific evidence supporting the Gel-Only approach from a controlled study: It was conducted in collaboration with Dr. Julien Louis’s team at Liverpool John Moores University, and we provided the gels for the study.

How the Study Was Conducted

Eleven trained cyclists participated in the study (8 men, 3 women; average VO₂max of 53 ml/kg/min). Each participant completed both test conditions in random order, with at least a six-day break in between. This way, each participant served as his or her own control.

1. Baseline measurements: First, performance metrics such as VO₂max and lactate threshold were determined. Participants were also able to test the Bicarb Gels in advance.
2. Fresh performance test: In a rested state, all participants performed three 6-second sprints, a 2-minute time trial, and a 12-minute time trial, each with the goal of achieving the highest possible average power output.
3. Two test days: 3 hours of cycling at moderate intensity (95% of the first ventilatory threshold), followed immediately by the same performance test in a fatigued state.

The only difference between the two test days was the nutrition. In both cases, the cyclists consumed 80 g of carbohydrates per hour via gels:

• • CHO: exclusively GEL 40 Neutral, without bicarbonate.
  • CHO + bicarbonate: four BICARB GELS at 0, 30, 90, and 150 minutes—totaling 20 g of bicarbonate—combined with Neutral gels. There was no prior loading.

The bicarbonate gels were intentionally scheduled for the first half of the ride so that blood levels would peak at the start of the time trials. The day before each trial, all participants received a standardized meal plan developed by nutritionists. Blood values, gastrointestinal symptoms, and the taste of the gels were recorded regularly.

Schedule for a test day. CHO = carbohydrate gels only (GEL 40 neutral 1:0.8), CHO+BI = with bicarbonate (dark gels = Bicarb GEL 40). GET = Gas Exchange Threshold, TT = time trial, Power Profiling = power test in a fatigued state. Figure: Norte et al., Scand J Med Sci Sports 2026, Figure 1, CC BY 4.0.

The Results

The 12-minute time trial yielded an average power output that was 12 watts higher with bicarbonate—approximately 6% more power than with carbohydrates alone. The effect was statistically significant and large (effect size g = 1.07).

Test (fatigued after 3 h)	Fresh	CHO	CHO + Bicarbonate	Difference
12-min time trial	269 W	239 W	251 W	+12 W, significant
2-min time trial	383 W	330 W	337 W	+6 W, not significant
6-second sprints (average)	899 W	866 W	879 W	+12 W, not significant

The blood bicarbonate level rose significantly. After 3 hours, it was 31.1 mmol/L, compared to 24.6 mmol/L without bicarbonate. On average, it increased by 5.8 mmol/L above the baseline value, reaching the range typically achieved even with conventional loading. For 9 out of 11 riders, the peak occurred at the end of the 3 hours, i.e., immediately before the performance tests.

Virtually no gastrointestinal complaints. Symptoms were negligible in both conditions and did not differ. No participant reported any complaints that would have impaired their performance, and no problems arose even after the tests.

No effect on metabolism during the ride. Heart rate, oxygen consumption, energy expenditure, and fat and carbohydrate oxidation did not differ. The bicarbonate thus did not affect the base ride itself, but only the intense efforts that followed.

What does this mean in practice?

The study shows for the first time that bicarbonate, when ingested exclusively via a gel during prolonged exercise, can cause significant alkalosis in the blood and improve performance toward the end of a strenuous effort. It does not completely prevent fatigue—fatigue levels were still lower than those of rested subjects – but it slows the decline in performance.

The authors attribute the fact that the effect – at around 6% – was greater than in earlier studies (usually 1 to 3%) to the “fatigued state”: When the body is already under stress, the additional buffer becomes more important. Why sprints and 2-minute time trials did not benefit remains unclear. Possible reasons include the order of the tests or the fact that very short efforts are less dependent on acid-base balance.

As with any bicarbonate strategy, not everyone responds the same way: 3 of the 11 riders did not improve. However, two of them showed no decline in performance even after 3 hours, so they had little to “save.”

It is important to keep the study’s limitations in mind for an accurate assessment:

• Small sample size: 11 participants are sufficient for initial evidence; larger studies and tests with professional athletes are still pending.

• Not blinded: The BICARB GELS taste different, so the participants knew what they were getting. An expectation effect cannot be ruled out.

• Fixed dose: Everyone received 20 g, regardless of body weight. As a result, lighter riders received a relatively higher amount.

• No comparison with loading: Whether taking the supplement during exercise is just as good, better, or worse than traditional carb loading was not tested.

• Always with carbohydrates: The effect of bicarbonate applies in addition to 80 g of carbohydrates per hour.

The authors outline two possible ways to use the product during races, explicitly as hypotheses for further research: either evenly spaced—for example, one BICARB GEL 40 per hour as a top-up—or strategically—three to four gels over a 60- to 80-minute period before a decisive phase of the race, such as a final climb.

Our recommendation therefore remains: BICARB GEL 40 is primarily a top-up after a loading phase. However, the new study shows that taking it on its own during exercise is also a promising approach for a decisive final phase or a final climb. Always try out any new strategy in training first—never during a race.

Conclusion

Bicarbonate does not necessarily have to be taken before the start. When ingested in gel form during a 3-hour ride, it significantly increased the blood buffer, boosted performance in the concluding 12-minute time trial by about 6%, and caused virtually no gastrointestinal discomfort. For endurance athletes whose races are decided only after hours of competition, this opens up new possibilities. Further studies are needed to determine whether taking it alone during exercise or combining it with a loading strategy is more effective.

Source

Norte BR, Hickman A, Muñoz Megias A, et al. Bicarbonate and Carbohydrate Co-Ingestion During Exercise in a Novel Gel Format Improves Time-Trial Performance After 3 h of Moderate-Intensity Exercise in Trained Cyclists. Scandinavian Journal of Medicine & Science in Sports. 2026;36:e70373. doi.org/10.1111/sms.70373

Disclosure: MNSTRY provided the gels for the study free of charge. According to the publication, MNSTRY had no influence on the study design, data collection, analysis, interpretation, or the decision to publish.