Fruit extract could help overcome the problem that 90% of runners have in the summer

Scientists are hailing a new study showing the “impressive” gut-protective effects of blackcurrant extract as a new solution to the dreaded “runner’s foot” that affects runners when they train in the heat. The supplement reduced symptoms in more than two-thirds of the recreationally active runners tested, all of whom were unaccustomed to running in the heat.

Runners and scientists alike say the discovery is “an extremely valuable prevention strategy for those of us who run in the heat” and a new means of gaining “an extra percent” in performance. Heat-induced gastric stress, which affects 90% of sports enthusiasts, whether they’re a professional athlete, a weekend warrior or a Parkrun fan, is one of the biggest problems for people who run in the heat.

Current prevention strategies are limited to several weeks of complex heat acclimation training, which is impractical and inaccessible to recreational runners. But a new study found that a runner’s berry extract supplement made from black currants offered “impressive” protection against exercise heat stress by improving barrier function and reducing overall symptoms of gastric distress in 73 percent of runners compared to a placebo.

The polyphenol-rich supplement suppressed heat-induced cell damage and “leaky gut” by up to 40% and reduced the body’s stress response.

Exertional heat stress is caused by exercising in high temperatures, which causes blood to be redistributed away from the digestive system to aid in thermoregulation, which stresses the gut. The resulting symptoms, commonly referred to as “Runner’s Trips,” affect both the upper and lower gastrointestinal tracts, which can lead to diarrhea, vomiting, nausea, stitches, and dizziness.

Mark Willems from the University of Chichester, a professor of exercise physiology who has published more than 40 studies with New Zealand blackcurrant extract to date, collaborated on the joint project between UK and US researchers.

Professor Willems said: “Although the protocol does not usually lead to severe symptoms, we saw nine participants report mild symptoms and two experienced severe symptoms. Impressively, the 92% of participants who experienced total gastrointestinal symptoms were reduced to 25% with blackcurrants. This is really significant.

“The take-home message is that if you typically have mild GI symptoms from running in the heat, they may be resolved by supplementing with New Zealand blackcurrant extract.”

Dr. Matthew Kuennen, associate professor at High Point University in North Carolina, said: “I am impressed with the ability of black currants to reduce markers of intestinal leakage and gastrointestinal barrier function during prolonged endurance exercise in hot conditions/ dry.

“Based on these findings, I would recommend blackcurrant supplementation as a potentially significant alternative when heat acclimation is not an option.”

They were subjected to moderate-intensity treadmill running in warm ambient conditions (34C/93.2F) after taking 600mg (two capsules) of CurraNZ blackcurrant extract for seven days. In addition to demonstrating various gut-protective effects, the study showed that blackcurrants are safe to use in hot conditions with no adverse effects on core body temperature or thermoregulatory processes.

Dr Stephanie Flippin, a professional ultra runner, coach and doctor who works with athletes, said: “There is no runner who has not experienced gastrointestinal distress. With current strategies limited to heat training itself, any type of mitigating and protective measure is extremely beneficial, and New Zealand blackcurrant extract provides an exciting new supplement for runners.”

She added: “Many times runners take antacids in an attempt to avoid these problems, but they have limited effectiveness. Until now, there has not been a supplement like this used in sports that could provide direct, scientifically validated protection. to those running just 7 days before an event.

“Furthermore, a large part of running is based on refueling, which is essential to be able to sustain 4-20 hours of running for those doing trials or ultramarathons. Gastrointestinal distress can bring down the house of cards and derail a person’s chances because they cannot tolerate their diet. New Zealand blackcurrant extract breaks new ground as an easy-to-use supplement for runners and to prevent the risks of heat stress.”

Dr Kuennen adds: “It is important to emphasize that exercise in the heat still provides the best adaptations, however, based solely on the improvements in gut barrier function that blackcurrants provide, it has merit in this cohort.”

He noted that there were some functions of gastrointestinal stress that the grain could not prevent. “We couldn’t verify that it made significant reductions in bacterial shedding or inflammation that occurs with exercise heat stress. So as it is, we have part of the picture, so there is still a chance that individuals will experience gastrointestinal discomfort during exercise and heat exposure.”