Exercise intensity could be impacting your gut

While exercise is great for both your mental and physical health, new research from Edith Cowan University (ECU) has found that exercise intensity could result in changes to the internal gut biome.

Ph.D. candidate Bronwen Charlesson undertook research into the impact of high and low training loads on athletes, in the hope of assisting athletes to improve their overall health, well-being and performance by better understanding the gut microbiome.

“Based on previous research, it appears that athletes have a different gut microbiota when compared with the general population. This includes greater total short chain fatty acid concentrations, alpha diversity, an increased abundance of some bacteria and a lower abundance of others,” she said.

Charlesson noted that while the differing microbiome between athletes and the public could likely be due to the differences in their dietary intake, fitness markers, which include oxygen uptake, have also been correlated.

Published in the Journal of the International Society of Sports Nutrition, this research uncovered that training load had an influence on gut health markers in athletes, with differences detected in short-chain fatty acid concentrations and the abundance of specific bacteria.

Although not part of this study, one of the potential reasons for the change in the gut could be the higher levels of blood lactate which results from higher intensity training. The lactate produced in muscle is transported to the gut to be metabolized, which could potentially result in increased bacteria in the gut.

Charlesson noted that the changes found in the gut biome when comparing high training loads to low training loads, were also related to diet.

“During low training load times, or periods of rest, athletes are often more relaxed about their diets, in this study we saw no change in total carbohydrate or fiber intake during period of rest but we did observe a decline in the diet quality of food eaten. This decline was related to increases in processed fast foods, decreases in fresh fruit and vegetables and a moderate increase in alcohol intake. These changes did impact the composition of the gut microbiome.

“Another observation made during the research was the significant slowing of gut transit times in athletes during low training loads. That slowing of transit time during the low training load appears to also be impacting the gut microbiome for an athlete.”

Charlesson explained that while it’s still unclear exactly how the gut influences athletic performance, there are some promising clues. For example, the gut may play a role in lactate metabolism and regulating pH levels, both of which could impact performance and overall athlete health. However, more research is needed, particularly into factors like training load, diet quality, and gut transit time, to better understand how these elements can be adjusted to enhance athletic performance.