It’s been an incredibly hot and dry spring and runners are already feeling the heat. This summer is expected to be even worse.
Summers and winters are expected to be warmer due to climate change. But what if dietary supplements could help fight the effects of heat during outdoor workouts?
Researchers say new trials show the compounds berberine, curcumin and blackcurrant could elevate your fitness, reducing body temperature and lowering heart rate.
And just one pill – at varying doses for each compound – could do the trick, Matthew Kuennen, an associate professor at High Point University, told Outside magazine.
“I would not recommend using these supplements full time,” he explained. “Rather, I would suggest using them, at the outlined dosages, in the week prior to a major competition or event.”
Kuennen said that people should take berberine, which is found in plants and being studied for its effects on body weight, in a 1.5-gram daily dose for a week.
Those running on a treadmill in a hot room for an hour found that it helped to reduce how hard the exercise was for people.
Those who took 500 milligrams of curcumin per day for three days – the active compound in the spice turmeric – had reduced signs of inflammation, blood tests conducted after their workout showed.
That was also something seen in people who took 600 milligrams of blackcurrant each day for a week, along with improved gastrointestinal health.
Blackcurrant is a small dark berry that’s commonly used to boost immune health.
Further physical examinations revealed that all three supplements reduce the rise in body temperature that happens when we exercise due to increased blood flow and muscles contracting.
Taking both berberine and curcumin reduced the rise in heart rate during exercise by three to eight beats per minute.
Although the researchers say the findings don’t prove the supplements caused these outcomes on their own.
They’re also no substitution for hydration in the heat – but could help people acclimate to hotter climates before big workouts or athletic competitions, said Kuennen.
While the supplements showed merit, Kuennen said in a statement that “the combination of these dietary supplements should be evaluated for potential performance benefits in a controlled laboratory environment.”
He also told Outside that it’s best to take curcumin and berberine with food to help improve the effects.
Although people historically take electrolytes, omega-3 fatty acids and vitamins to beat the heat, no dietary supplements are approved by the U.S. Food and Drug Administration before they are marketed – and most people get enough vitamins and mineral from their food.
“It is really important that dietary supplements be viewed as adjuncts, rather than replacements, for established heat illness countermeasures,” Kuennen said.
The findings will be presented this weekend at the 2026 American Physiology Summit in Minneapolis.
