Can Exercise Boost My Gut Health?

Your intestines play host to trillions of microorganisms, including bacteria, viruses, fungi, and other microbes. It's a thriving community known as the microbiome. Researchers say they are just beginning to understand all the ways the diversity of your microbiome impacts your health. So far, evidence suggests that a diverse, healthy gut microbiome can aid digestion, regulate the immune system, help protect against certain diseases, and even boost mood.

Plenty of data suggests that exercise may also be part of the healthy-gut equation, although overdoing it (such as an ultramarathon) can lead to microbiome imbalances and gut problems.

There's a lot going on when you exercise - you move more oxygen through the bloodstream and to the brain, your core body temperature heats up, and your blood flow redirects to different organs. Researchers suspect these conditions can help gut bacteria flourish, though the exact mechanisms remain unclear, says Taylor Valentino, PhD , a postdoctoral researcher at the University of Utah in Salt Lake City, where he studies the relationship between muscle development and the microbiome.

"Exercising causes important changes that help gut microbes to bloom and convert, and, coinciding with that, we get molecules our bodies can use," Dr. Valentino says. Here's a breakdown of the research that explores how exercise and the gut may be linked, as well as steps you can take to help nurture a lively gut microbiome through your workouts.

Can Exercise Boost Gut Health?

Most gut bacteria have a symbiotic relationship with the body: In short, you nourish and feed them, and they produce vitamins, fatty acids, and amino acids that your body uses for things like immune function, digestion, mood regulation, and more.

Regular exercise speeds up the process, increasing the diversity of microbial species in the gut and encouraging bacteria to flourish, says Jacob Allen, PhD , an associate professor of exercise physiology at the University of Illinois in Urbana-Champaign.

And a growing body of research suggests that exercise may well promote a diverse gut microbiome. One caveat as you read on: Most of these studies did not strictly track or control what participants ate. Human microbiomes are highly individual, and diet can make a significant difference. Future trials will benefit from locking down meal plans so researchers can separate exercise-related changes from food-related ones.

Cardio Breeds Bacteria That Turn Waste Into Fuel

One of the main ways scientists think exercise benefits the gut is by increasing levels of butyrate, a short-chain fatty acid (SCFA). Produced by certain gut bacteria, butyrate is the main fuel source for the cells lining the colon and also helps support the gut barrier.

Regular moderate-intensity exercise appears to promote the growth of beneficial bacteria such as Faecalibacterium prausnitzii , one of the gut's major butyrate producers. Exercise also seems to encourage the growth of Akkermansia muciniphila , which helps support the gut's protective mucus layer.

During higher-intensity exercise, your muscles produce lactate. Researchers have found that other gut bacteria, including Anaerostipes and Eubacterium species, can convert that lactate into butyrate, effectively turning a waste product into fuel your gut can use.

A recent review of 89 studies (47 in humans and 42 in animals) found that while high-intensity interval training (HIIT) initially stresses the gut, repeated training appears to promote microbial changes that support this waste-to-fuel conversion.

After participants stopped exercising, however, the microbiome quickly returned toward its pretraining state. This shows that consistency may be key to exercise's benefits for gut health.

Moderate-Intensity Exercise Can Reduce Leakage in the Gut Lining

The gut lining, or epithelium, is a vital barrier between your gut and the rest of your body that's also crucial for absorbing nutrients. Its structure is a mesh of cells.

And when working well with a tight mesh, this barrier prevents lipopolysaccharides (LPS), the toxic fragments of dead bacteria, from crossing the leaky barrier, entering the bloodstream, and triggering increased inflammation, according to research.

A review of human clinical and randomized trials found that moderate exercise increased levels of proteins linked to a tighter mesh by 15 to 20 percent and rebalanced inflammatory markers toward a profile suggesting lower inflammation. But moderation is key: The researchers also found that more than 90 minutes of intense exercise loosened the "mesh" of cells, increased inflammatory markers, and led to a temporary increase in "bad" bacteria such as Escherichia coli ( E. coli ).

Clinical Trials Are Looking at the Link Between Gut Health and Exercise

Several clinical trials are directly assessing the link between physical activity and the diversity of your gut microbes.

For example, the FITGut-W Trial is recruiting premenopausal females with a range of body mass indices (BMIs) to use a stationary bike for a single, controlled 30-minute session. Just before and after the session, the researchers will take blood and stool samples. Participants also won't be allowed to use antibiotics or prebiotics or make any changes to their normal diet in the testing period.

This will test the gut's ability to produce SCFAs in response to exercise without any dietary changes.

Similarly, the GUTFIT Study will measure gut microbial concentrations in stool samples from 40 people with type 2 diabetes before and after exercise. This trial will test the impact of different exercise intensities over a 16-week period to see whether exercise intensity is linked to the extent of blood sugar changes and the diversity of gut microbes.

High-Volume Endurance Training May Damage the Gut

Not all levels of exercise help the gut, and some can be damaging. A viewpoint paper published in 2026 notes that many long-distance and marathon runners experience gastrointestinal (GI) symptoms such as heartburn, nausea, diarrhea, and blood in the stool during intense, prolonged efforts.

The viewpoint paper notes that intense, prolonged exercise diverts oxygen-rich blood away from the gut, which can damage cells in the gut lining and loosen the barrier. Researchers have tracked this using a marker of gut cell damage called I-FABP, which rises after sustained, demanding effort.

The relationship between gut health and mood is another significant point. The researchers propose that this gut damage may combine with other factors to affect endurance athletes' mental health, though they're clear this is a hypothesis. Longer-term studies are needed to test whether gut barrier function plays a real role.

Does Good Gut Health Support Exercise?

Valentino points to a study that found marathon runners' stool samples have higher levels of another bacterium, called Veillonella atypica , than non-runners. The concentration of this microbe was higher after workouts and even more elevated after a marathon.

Veillonella is a microbe that consumes lactate - which our bodies produce during a hard workout - and converts it into propionate, an SCFA that boosts our energy levels. The study authors suggest that exercise increases Veillonella microbes in the gut, providing the extra energy boost needed for endurance running.

But while the boost in levels of this bacteria may look promising, other studies, such as the paper that looked at gut damage after extended, grueling runs, note that the microbiome isn't the whole picture when it comes to exercise and gut health.

5 Ways to Make Your Exercise Routine Gut-Friendly

Research in this area focuses on cardio and consistency.

1. Focus on Cardio

For now, the research connecting exercise to improved gut health has focused mostly on aerobic exercise, and less so on resistance training, like weight lifting. That doesn't mean pumping iron won't help your gut health or lacks other notable benefits. It's just that this area has been studied far less in relation to the gut, Dr. Allen says.

Allen ran a study in which participants did aerobic or cardiovascular exercise, such as jogging or cycling, three days a week for 30 to 60 minutes at a target heart rate of 60 percent of their heart rate reserve, working up to 75 percent. This led to an increase in beneficial gut bacteria and in SCFAs such as butyrate and acetate among healthy-weight, lean participants.

Researchers think part of the reason this works is that harder effort temporarily redirects blood flow away from the digestive tract, and the gut adapts to that mild, repeated stress.

The benefits in Allen's study were evident at between 60 and 75 percent of the heart rate reserve. At this intensity, you should be able to talk comfortably and maintain regular breathing, while 75 percent is classified as "vigorous exercise," where you may be breaking a sweat, and your breathing speeds up, says Marc Cook, PhD, an associate professor of kinesiology at North Carolina A&T State University in Greensboro.

Other exercises, like rowing, swimming, or skipping, can also be effective ways to get your cardio in, Dr. Cook says.

2. Be Consistent

To keep the production of good microbes in your gut going, you'll need to keep exercising and make it part of your overall lifestyle.

"Consistency is No. 1, because you can lose the beneficial effects if you don't keep exercising," Cook says. Some of the research mentioned above suggests that the gut benefits fade once you stop working out.

Just like your stamina decreases if you quit running for a few weeks, your gut microbiome will lose out on the production of good microbes once you stop exercising, Cook warns.

3. Start Small

If you're starting at square one and aren't used to exercising, ease your way in, Valentino says.

"Don't go from couch to marathon," he advises. "The goal is giving your microbiome a constant fuel source through exercise." This can help you prevent injuries and build a long-lasting, sustainable, enjoyable habit.

4. Get Outdoors

Exposure to nature increases our exposure to diverse ecosystems and the bacteria within them. "If we're outdoors, running in a park, or along the ocean, we're breathing in very diverse communities of bacteria that are in the air," says Christopher Lowry, PhD , a behavioral neuroscientist and an associate professor at the University of Colorado in Boulder, where his research focuses on the gut microbiome and anxiety-related disorders.

He points to a Finnish study that found that children who played outside on the forest floor, in the dirt, and among plants and flowers had a richer, more diverse gut microbiome and a less inflammatory immune system than their peers in an urban day-care setting.

5. Don't Forget Nutrition

Your diet has just as much impact on your gut health as your exercise regime, Cook says. Before you go grocery shopping and meal planning, take note: The gut microbiome loves fermented foods, which contain a variety of bacteria and yeast.

Natural probiotics include:

• Yogurt

• Kefir

• Kombucha

• Miso

• Sauerkraut

• Kimchi

Your gut microbiome also thrives on plant diversity. That means you ought to load up on vegetables, fruits, nuts, and seeds. A landmark study that used stool samples and self-reported dietary logs from more than 10,000 people called for eating 30 different plant types per week to bolster microbiome diversity and optimize gut health.

The Takeaway

• Regular exercise, particularly moderate-intensity cardio, can promote a diverse gut microbiome by encouraging beneficial bacteria that convert waste products into fuel and by strengthening the gut lining to reduce inflammation.

• Consistency is key, as research shows that gut health benefits fade once you stop exercising. Aim for regular aerobic workouts at 60 to 75 percent of your heart rate reserve.

• More than 90 minutes of intense exercise or high-volume endurance training can damage the gut lining and cause gastrointestinal symptoms, so moderation is important.

• Combining regular exercise with a diverse, plant-rich diet that includes fermented foods can help optimize your gut health.

EDITORIAL SOURCES

Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy . We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.

Resources

1. Gut Microbiome. Cleveland Clinic . August 18, 2023.

2. Clauss M et al. Interplay Between Exercise and Gut Microbiome in the Context of Human Health and Performance. Frontiers in Nutrition . June 10, 2021.

3. The Health Benefits and Side Effects of Butyrate. Cleveland Clinic . July 11, 2022.

4. Alsinani Y et al. Exercise and the Gut Microbiome: From Mechanisms to Clinical Applications. Nutrients . February 26, 2026.

5. Hoseini R et al. Exercise intensity-mediated regulation of gut epithelial cells and immune function in gut microbiota dysbiosis. Journal of Translational Medicine . November 26, 2025.

6. Aerobic Exercise for Gut Health (FITGut-W Trial). WithPower .

7. Thomson AM et al. Understanding the gut microbiome through a fitness intervention of aerobic and resistance training for individuals with type 2 diabetes mellitus (GUTFIT: A Study Protocol). PLoS One . February 23, 2026.

8. Del Colle A et al. Exercise-induced intestinal barrier dysfunction: a potential contributor to athlete mental health. BMJ Open Sport & Exercise Medicine . June 30, 2026.

9. Scheiman J et al. Meta'omic analysis of elite athletes identifies a performance-enhancing microbe that functions via lactate metabolism. Nature Medicine . June 24, 2019.

10. Allen JM et al. Exercise Alters Gut Microbiota Composition and Function in Lean and Obese Humans. Medicine & Science in Sports & Exercise . April 2018.

11. Roslund MMI et al. Biodiversity intervention enhances immune regulation and health-associated commensal microbiota among daycare children. Science Advances . October 14, 2020.

12. McDonald D et al. American Gut: an Open Platform for Citizen Science Microbiome Research. mSystems . May 15, 2018.

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