Physical Activity

Does Gut Health Impact Athletic Performance?

In our quest for muscle growth and progressing in our training, it’s easy to forget that gut flora (and the role it plays in maintaining our health) can have an impact on athletic performance. Gut health extends to not only digestion but also to our immunity, nutrition absorption and recovery.

What Does Your Gut Do?

A quick refresher course: the GI tract (specifically the stomach and intestines) is home to millions of bacteria, called gut microbiota, or gut flora. Gut flora outnumbers all of our other cells by 10:1, and they’re comprised of hundreds of different strains. Probiotics are a specific type of gut flora, and essentially, they’re part of the foundation for our gut health, and again, our health in general.

The function of gut flora is to break food down, recognize pathogens, improve the health of our intestinal wall and facilitate new cell growth. A properly functioning gut often goes unnoticed, but a poorly functioning one is felt pretty quickly. The density of gut flora and how it ideally creates thick, tight junctions is similar to how fabric is woven from thread — the tighter the knit, the better (1).

Tipping the scales against gut flora is extremely easy to do and it creates a “looser” knit at the tight junctions. The most common issues that arise from low gut flora are leaky gut (intestinal permeability) and gastritis (stomach permeability). Leaky gut and gastritis are exactly what they sound like: toxins, foreign bodies and all of the things we avoid as health-conscious individuals are able to push themselves through the intestinal walls and the stomach.

person holding heating pad to stomach to improve gut health pain

At the very least, it can cause anything from mild discomfort (such as bloating or heartburn) to more extreme physical pain. Additional effects of leaky gut and gastritis include frequent and recurrent allergies, asthma, recurrent skin conditions, IBS, colitis, certain autoimmune diseases — the list goes on and on. Increasing amounts of research are being done on the links between gut health and other common illnesses (2).

If you feel that any of these symptoms apply to you, it’s worth it to continue researching and speak to your doctor.

How Can You Damage Your Gut Flora?

There are a few commonly known ways in which you can harm gut flora. A round of antibiotics will often kill good bacteria along with the bad. Pollution, GMOs and chemicals in our environments are all — to varying extents — absorbed by our bodies. The foods we consume, including too much caffeine, alcohol, sugar and processed foods, will also deplete a healthy gut (3).

coffee hurting gut health

Interestingly enough, however, it’s also what we physically do that has an effect.

How Gut Health Impacts Performance

Think about this: have you ever competed or pushed your body to the limit in one physical way or another, only to then come down with a slight cold, muscle aches and extreme exhaustion after? Well, what’s commonly referred to as “overdoing” it or “delayed onset muscle soreness” may also be indicative of an individual’s gut health.

How? As previously mentioned, when we exercise, our bodies divert energy to the location of the stressor. This is what leads to PRs and to an increase in endurance, but it’s also what affects the numerous other processes that we aren’t noticing  — breathing, digestion, etc.

Diverting energy to an inflicted physical stressor is done fairly efficiently by a healthy gut. Blood flow increases to those areas, and digestion is slowed. An inflammatory chain reaction occurs and amino acids, as well as proteins, rush to fill in the gaps and to strengthen our muscles and bones. Over time, we grow and improve our performance. A not-so-healthy gut has a much harder time.

woman exercising to improve gut health

Here are a few more ways performance and poor gut health are linked.

  • The immune system is compromised from not having enough interferons, which are protein precursors that fight off pathogens (4). Interferons thrive amongst probiotics and in a healthy gut environment, so there actually is a greater chance for you to catch a cold (5).
  • Additionally, this means that when inflammation occurs at various points on the body, a compromised immune system will have more of an issue strengthening the area. The chances for injury start to increase if we keep reusing the same muscles but aren’t able to improve upon them. Think long term “wear and tear.”
  • Digestion is inefficiently slowed, stopped or sped up, depending on one’s system. Blood flow and body heat are moved away from the digestive organs during training and rerouted to the organs that need them. It won’t necessarily resume properly after training is finished. If it doesn’t…
  • … nutrients from food and supplements won’t be properly processed, used or stored, meaning the nutrients, vitamins and minerals won’t be fully absorbed.
  • Over time, consistently missing the physical goals you set for yourself or potentially even falling short of where you were can affect your confidence and your overall mood.

Fortunately, maintaining gut health is somewhat of a simple process. The right foods and supplements certainly help. If you haven’t already, take a probiotic supplement daily. It should contain at least six separate strains and should have lactobacillus and bifidobacterium.

Fermented foods (such as kombucha and sauerkraut) are thought to contain even more strains of probiotics than supplements.

sauerkraut to improve gut health

Probiotics usually begin to work within 24 hours.

One study found that especially in endurance athletes, probiotics do help to increase athletic performance over time by minimizing intestinal permeability and increasing anti-inflammatory responses from specific cells (6). Another study found that male athletes have a wider variety of gut flora than their sedentary counterparts. No conclusions were drawn as to why, but there’s an idea that continual exercise promotes a stable and healthy environment for different strains of gut flora to thrive (7).

If you take probiotics, you should also supplement with prebiotics. The prebiotic is a lesser discussed category, mostly for the reason that they aren’t microorganisms in the traditional sense, but rather they’re the building blocks for probiotics to thrive.

They’re non-digestible carbohydrates, and they work in conjunction with probiotics by supplying necessary nutrition. Broccoli, onions, garlic, dandelion root and kale are some examples. A high-quality supplement, such as Synbiotics SB3, will take the guesswork out of calculating how much you took in a day and it’ll give you the best of both worlds (8).

High-quality fish oil contains necessary omega-3s. They’re essential to help heal inflammation, and they can help to prevent further damage. Digestive enzymes and DGL (derived from licorice root) also aid in healing the gut. It’s important to keep stomach acid balanced and to avoid inflammatory causing foods (9). Coconut oil, bone broth and fermented vegetables can aid in repairing leaky gut (10).

turmeric to improve gut health

Additionally, turmeric and the amino acid L- glutamine should be incorporated into your diet as a means to fight inflammation and reduce leaky gut symptoms (11).

Neglecting gut health for a short period of time probably won’t affect performance in the short term, but we can safely say that gut health and performance are connected in an ongoing cycle. Every solid training program should include gut maintenance as part of its nutritional protocol (11). Athletes are always looking for ways in which they can improve their performance or for reasons as to why they’re falling behind. Considering how far we push ourselves to hit our PRs, supplementing for a healthy gut is probably one of the easiest things we can do.


  1. The Gastrointestinal Tract.” Mayo Clinic. Dec 14, 2014.
  2. Regulation of Tight Junction Permeability by Intestinal Permeability and Dietary Components.” Roy, Nicole. May 1, 2011.
  3. Impacts of Gut Bacteria on Human Health and Diseases.” Zhang, Yu-Jie., Li, Sha., Gan Ren-You., Zhou, Tong., Xu, Dong-Ping., Li, Hua-Bin,.  April 5, 2015.
  4. Probiotics and Commensals Reverse TNF-alpha- and IFN-gamma-induced Dysfunction in Human Intestinal Epithelial Cells.” Resta-Lenert, S., Barett KE. March 13, 2006.
  5. The Role of Gut Microbiota in Immune Homeostasis and Autoimmunity.”Wu, Hsin-Jung, Wu, Eric. Jan 12, 2012.
  6. Probiotic Supplementation Affects Markers of Intestinal Barrier, Oxidation, and Inflammation in Trained Men.” Lamprecht, M., Bogner, S., Schipper, G., Steinbauer, K., Fankhauser, F., Hallstrom, S., Schuetz, B., Greilberger, J.F. September 12, 2012.
  7. Exercise and Associated Dietary Extremes Impact on Gut Microbial Diversity.” Shanahan, Fergus. March 23, 2014.
  8. Probiotics, Prebiotics, and Synbiotics: Gut and Beyond.” Vyas, Usha, Ranganathan, Natarajan. July 20, 2012.
  9. 8 Supplements to Heal a Leaky Gut. ” Dr. Amy Myers. May 2, 2013.
  10. SSE #114: Nutritional Recommendations to Avoid Gastrointestinal Distress During Exercise.” De Oliviera, Eric Prado. December 14, 2015.
  11. Possible Links between Intestinal Permeability and Food Processing: A Potential Therapeutic Niche for Glutamine.” Rapin, Jean Robert, and Wiernsperger, Nicolas. 2016, Jan 23.