Your Workouts Are Making You Sick. This is What You Can Do about It.

Your Workouts Are Making You Sick. This is What You Can Do about It.

We all know that being physically fit is good for us, and good for our health. Many of us don’t know, however, that health clubs can be some of the unhealthiest places to spend time.


  • The norovirus, which leads to stomach pain, nausea, vomiting, and diarrhea, *can survive for up to a month* on the surface of exercise equipment.
  • The common-cold-causing rhinovirus is commonly found on cardio machines, even after a casually wipe down with sanitizer.
  • Trichophyton rubrum and Trichophyton interdigitale, the fungi responsible for athlete’s foot infections thrive in moist environments such as locker room carpets and gym showers.
  • Free weights, exercise mats, and virtually anything someone can be touch at a gym has been tested and found to contain disease causing pathogens, including MRSA, a bacteria that is resistant to some antibiotics.

We could go on for hours about the pathogens found on the various surfaces at health clubs, and that much more than simple hand-washing is needed to protect yourself, but Fitness Magazine has already done an excellent job of detailing these things.

For the ultimate in post-workout sickness prevention we recommend that you read their article after you finish reading ours (of course).

Rather than getting into the weeds about gym germs, we will address this issue from a different angle; by attempting to reduce the impact the germs have on our bodies.

The good news is that mere exposure or contact with bacteria, viruses, and fungi is not a guarantee that one will get sick. A healthy immune system is capable of fighting off many of these pathogens before infections set in.

The bad news is that intense workouts may temporarily reduce the amount of “natural killer” immune cells available while you’re still at the gym.

At the beginning of your workout the number of “natural killer” cells in the bloodstream increases dramatically. Then these immune cells quickly fall to levels lower than they were before you started your workout, and could remain low for hours.

We hope we haven’t scared you out of your next workout, especially since exercise does have beneficial effects on the immune system long term. How to better support your immune system during these prolonged periods of exertion is the focus of today’s article.

Two amino acids, taken together, once daily seem to prevent the reduced immune response to exertion in humans after just two weeks of consistent use. (R) (R). The two amino acids are l-cystine, and the non-protein amino acid l-theanine, found mainly in green tea.

N-Acetyl-Cysteine, also known as NAC, is the more common supplement form of this amino acid. NAC is converted to l-cystine in the body.

Each amino acid appears to have positive effects on the immune system individually.


  • NAC reduced flu-like episodes amongst the chronically ill by 78% in an Italian study. The placebo group only had a 25% decrease of flu-like episodes. (R)
  • NAC has been shown to improve immune function in postmenopausal women. +NAC reduced flu-like episodes amongst the chronically ill by 78% in an Italian study. The placebo group only had a 25% decrease of flu-like episodes. (R)
  • NAC stimulated “natural killer” activity in aging animal models. (R)

Together, theanine and cysteine appear to provide powerful immune support, and help to prevent the reduction of “natural killer” cells after high-intensity resistance exercise.


  • Theanine, along with green tea catechins helped prevent the flu virus among Japanese healthcare workers. (R)
  • Theanine has been shown to decrease the experience of stress, and this may have a positive impact on the immune system indirectly.
  • Theanine improves immunity in animal experiments. (R)

The study referenced above used 700 mg of cystine and 280 mg of theanine once daily. These exact amounts might be difficult to find in supplement form, but we were able to find sustained release tablets of 600 mg N-Acetyl-Cysteine, and separately, 200 mg capsules of L-Theanine.

One NAC tablet, and one L-Theanine capsule will provide a little less than the amounts for which the study was based. Increasing to two of each may be an option after a few days of trying the lower dose without ill effects. As always, discuss making any additions to your dietary supplements with a health professional.

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Add 600-1200 mg n-acetyl-cysteine (NAC) and 200-300 mg l-theanine to your daily supplements.

NAC might help reduce muscle fatigue during workouts, which is another benefit of adding this to your workout stack.

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Because of their potential to support healthy immune function and inflammation, this same combination of amino acids has also been used in human studies to reduce the side effects of chemotherapy, speed recovery after surgery, enhance recovery after gastrectomy, and add to the effectiveness of flu vaccinations in elderly patients.

In experimental animal models, cystine and theanine have been successful in protecting against flu virus and sepsis, and increasing survival after gut ischemia-reperfusion.

Upon the recommended of his physician, one of the co-founders of Little Change has been supplementing with NAC for more than 15 years, and periodically adds L-Theanine. He has not knowingly succumbed to any communicable disease as the result of working out at health clubs, and avoids the gym when feeling physically exhausted as an added safeguard.

NAC is part of his overall immune support stack, and he often boasts of going several years between colds and the other infections diseases making their rounds. He believes NAC to play an important role in his seemingly strong immune support.

Please let us know in the comments if this stack works for you. Feel free to share other ideas for staying healthy at the gym.

To keep this article up to date, we would like to mention there is a recent study that suggests the reduction of immune cells in the blood might indicate that they are being recruited elsewhere in the body where they are needed during exercise, such as the lungs. This implies that intense workouts do not impact the immune system as profoundly as once thought.

These new findings don’t negate the need for strong immune support while working out at a public gym or other shared space. Continuous exposure to pathogens makes us more likely to succumb to them, and good sanitation practices, in conjunction with strong immunity can help keep us from becoming their next victims.

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