Why You Need to Exercise Outdoors: Part 1—The Problem With Pollution in Gyms

In this episode, learn the benefits of exercising outdoors, the problem with polluted gyms, and more. 

Ben Greenfield
5-minute read
Episode #239

And then there’s the issue with mold. My friend Dave Asprey just released a documentary called “Moldy,” about hidden sources of environmental mold that deleteriously affect the health of more than 100 million people worldwide. Indoor mold can be even more damaging than well-known pollutants such as asbestos and lead, and unfortunately, mold is common in gyms, locker rooms, swimming pool areas, and saunas because they are full of bacteria and moist air. These inhaled mold toxins can be just as harmful as mold that you eat from a piece of old food.

I’ve worked at plenty of gyms and health clubs and know for a fact that the cleaning procedures at many, many facilities are less than stellar, and that mold is often ignored or left to hang out for long periods of time (a good test for the cleanliness of your gym is to leave a small piece of chewed gum in a corner, ledge, crack, space, etc., and see how many days it takes to disappear—you’d be shocked!) So, if your gym or the locker room area in your health club is somewhat humid, smells like sweaty socks, or has frequent puddles or pools of water that are there throughout the day, there are likely mold and fungus issues.

Next, there’s the problem with something called “particulate matter” in indoor spaces such as gyms. Particulate matter is a mixture of solid and liquid droplets such as nitrates, sulfates, organic chemicals, metals, and soil or dust, and they can come from rubber mats, metal plates, and dumbbells banging together, and even dead pieces of skin from other people working out (ew!). The problem is that these particles are small enough to pass through your nasal cavities and enter your lungs, especially when you’re breathing hard in an indoor exercise environment.

Unfortunately, over a quarter of the gyms in the study I mentioned earlier exceed the indoor limit for these kind of particles. It is true that HEPA air filters and a good gym cleaning protocol can help out quite a bit in this situation, unless the cleaners are made of toxic chemicals, which can then enter the air and get recirculated. Even school gymnasiums have been found to contain significantly high levels of particulate matter, such as dust, soil, and bacteria that can trigger immune, asthmatic and allergic responses in susceptible children.

Next is the issue of volatile organic compounds (VOCs). Exposure to VOCs in high levels can cause skin irritation, neurotoxicity, and hepatotoxicity (toxicity of the liver). The scary fact is that over eighty percent of the gyms that have been studied exceed the acceptable level of unsafe VOCs, which include compounds such as formaldehyde, fire retardants, acetone, and other substances that off gas from carpeting, furniture, cleaners, paint, among others. Levels of VOCs tend to be higher in gyms with newer equipment, and also in spaces that have been recently cleaned (due to the cleaning chemicals used).

Finally, there are all those synthetic fragrances, colognes, and deodorants that your fellow gym-goers have plastered all over their bodies and that are filling the air around you. I address these type of hormonal and endocrine disruptors in the episode on estrogen dominance, but these can also be a serious issue that, frustratingly, can be out of your control unless you have the courage to ask the woman running on the treadmill next to you to slather on a bit less perfume.

If you have more questions about the problem with pollution in indoor gyms and why you need to exercise outdoors, then leave your thoughts over at the Facebook.com/GetFitGuy page!













Gym image courtesy of Shutterstock.


All content here is for informational purposes only. This content does not replace the professional judgment of your own health provider. Please consult a licensed health professional for all individual questions and issues.

About the Author

Ben Greenfield

Ben Greenfield received bachelor’s and master’s degrees from University of Idaho in sports science and exercise physiology; personal training and strength and conditioning certifications from the National Strength and Conditioning Association (NSCA); a sports nutrition certification from the International Society of Sports Nutrition (ISSN), an advanced bicycle fitting certification from Serotta. He has over 11 years’ experience in coaching professional, collegiate, and recreational athletes from all sports, and as helped hundreds of clients achieve weight loss and fitness success.