Beating the Heat: How Bicarb Supplementation Supports Performance in Hot Conditions

At FLYCARB we’ve seen impressive performances by athletes using BICARRB in hot conditions. At the 2024 World Championships 100km in India, three members of the British men’s team used BICARRB to help manage extreme heat and challenging terrain, helping them secure bronze medals. We’ve also seen standout marathon results. At London 2025, Alex Milne ran 2:14:03, a 2.5-minute personal best, on an unexpectedly warm day, then went on to place 6th at the iconic, and notoriously hot, Comrades Ultramarathon.

To explore these effects in more detail, we partnered with CORE, whose body temperature sensor tracks core temperature and calculates a Heat Strain Index, a metric of how much heat stress the body is under. Using their sensor, athletes can optimise heat training, monitor adaptation, and assess performance under thermal stress.

We are both big proponents of the CORE “train hot, race cool” philosophy, and we wanted to gain a better understanding of how BICARRB fits into the puzzle.

Research on Bicarb Usage in Hot Conditions

Sodium bicarbonate has long been studied for its performance-enhancing effects in endurance sports, with its role as a lactate buffer well established. Recent research has also highlighted its potential to improve performance for athletes under heat stress. Studies have shown that sodium bicarbonate supplementation can support performance in hot conditions in the following ways:

  • Reduces perceived exertion. This helps make races in hot conditions feel more manageable and allows athletes to sustain higher intensities with lower strain levels
  • Enhances recovery and performance in repeated efforts, helping sustain power output late in a race or across multiple events in a single day.
  • Supports blood flow to the brain. This helps maintain focus and decision-making as fatigue increases in hot conditions.

In practical terms, the research suggests that bicarb supplementation can help athletes maintain control, reduce fatigue, and perform closer to their peak, even in hot, demanding conditions.

Testing CORE and BICARRB Together

To see the effects firsthand, we ran a small personal trial combining heat training with and without FLYCARB’s BICARRB. The test was conducted under controlled conditions for environment, clothing, and power output on an indoor cycling session. Using the CORE sensor we tracked skin and core temperature and Heat Strain Index. We also logged heart rate and perceived effort.

While the test was based on personal trials, our results echoed the scientific findings: during the test with BICARRB, perceived effort felt lower, core temperature and Heat Strain Index responses were more stable, and the session felt more manageable overall. Notably, skin temperature was lower with BICARRB, suggesting a stronger sweat response.

The data for the trial is presented in the graph below, and both FLYCARB and CORE welcome dialogue with academic partners to further the research into the impacts of bicarb on exercising in hot conditions.

CORE Temperature Response

Conclusions

Research, athlete experiences, and personal trials show that bicarb can be a game-changer in hot conditions. Using bicarb supplements like FLYCARB’s BICARRB helps improve fatigue resistance, support more efficient breathing, maintain mental focus, and reduce perceived exertion.The BICARRB Energy Mix is also designed to protect the bicarbonate through stomach acid, eliminating gastrointestinal issues sometimes associated with bicarb.

By combining bicarb with the CORE body temperature sensor, athletes can take this a step further. CORE provides live insights into core temperature, skin temperature, and Heat Strain Index, allowing athletes to monitor heat stress, optimise training sessions, and make smarter pacing and cooling decisions in hot conditions.

Together, CORE and FLYCARB give athletes the tools to train hot and race cooler, maintaining peak performance when it matters most.

About CORE

CORE develops advanced wearable sensors that track core body temperature, skin temperature, and Heat Strain Index in real time. Designed for athletes, CORE provides actionable insights to optimise training, monitor heat adaptation, and improve performance in hot conditions.

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