September 11, 2018

When I'm not submerged in ice for this recent Outside Magazine cover, or sitting on airplanes to bombard cities like Tokyo with biohacking tips, I’ve recently been exercising outdoors far, far more than I usually do. As a matter of fact, these days – come rain, snow or shine – I’m only in the gym about an average of once every two weeks or so. This stands in pretty stark contrast to the years when I was a bodybuilder, spending 1.5-2 hours in the morning pumping iron at the health club, typically followed by another visit later in the afternoon or early evening – or even the years when I was an Ironman triathlete and would think nothing of hammering away on the gym treadmill for a 90 minutes to 2 hour long session. 

Now, don’t get me wrong: if the only thing that keeps you physically active, exercising, and motivated to train or live healthily is a gym membership and a regular visit to your health club, then that’s far, far better than laying on the couch eating twinkies and watching Westworld.

But at the same time, there are some big problems with gyms and some big benefits to being outdoors that you’re going to discover in this article. You'll discover the problem with gyms and tight indoor spaces where lots of people are exercising, along with the potent fixes that nature can provide. You'll also get plenty of tips to exercise outdoors, no matter where you live.

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The Problem With Gyms

Recent studies (a full list is provided at the end of this article) have highlighted the fact that there are concerningly high levels of carcinogens in the air of the average fitness center, as well as significant amounts of harmful bacteria on the surfaces of fitness equipment such as treadmills and weight training machines.

I'll address the problem with air pollution more thoroughly towards the end of this article – but I want to address the elephant in the room first: compared to skipping exercise altogether, it’s still better to exercise even if you’re exercising in a polluted environment. But at the same time, the CDC, the EPA and plenty of medical journals have found that exposure to air pollutants in urban areas is linked to higher rates of asthma and abnormal heart rhythms, and increases your risk of death from cardiovascular disease, respiratory diseases, and all causes. What this means is that if you actually do have the choice between, say, exercising in your backyard or a nearby park or forest versus exercising in the gym, you’d be far better off with the former.

And then there’s recent data showing that the indoor air quality in some fitness centers may be just as harmful to health as the air pollutants in urban areas. For example, one study in the journal Building and Environment found unacceptably high levels of carbon dioxide, formaldehyde and other volatile organic compounds (VOCs), and particle pollution in multiple indoor fitness centers.

Next, there’s carbon dioxide (CO₂). Since expiration (the primary mechanism via which we lose fat, as you can read here) releases CO₂, its levels significantly rise when there are lots of people huffing and puffing in a room, especially if that room is poorly ventilated. So, the more folks you cram into an indoor space running on treadmills, rowing, riding bikes, lifting weights, and jumping around, the worse the quality of air in that space. This is why I’m a bigger fan of home gyms compared to commercial gyms, and also a fan of getting in and out of a gym quickly by utilizing a strategy such as High-Intensity Interval Training (HIIT).

This study showed the highest levels of CO₂ in an interior room used for indoor cycling spin classes. I’m not saying that these CO₂ levels are toxic and going to kill you, but they’re not completely harmless either. This is all the more concerning when you consider the fact that most building owners (gyms often lease from building owners) save money by recycling used air instead of heating or cooling fresh air from outside.

And then there’s the issue with mold. On the website SurvivingMold.com, you can learn plenty more 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 kinds 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.

Now, let's compare all this to outdoors exercise…

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The Therapy & Benefits Of Outdoors Exercise

In my podcast episode, “Forest Bathing, Sleep Hacking, Cell Phones & Water: The Underground Guide To Lowering Cortisol When Nothing Else Seems To Be Working,” my guest Evan Brand and I discuss the amazing research that shows that something as simple as spending time in the trees, walking in forests, exercising on nature trails, and hiking outdoors exposes you to tiny particles and phytochemicals that plants release, and this, in turn, helps decrease salivary cortisol, depression, and anger.

Also, in my last article on the fascinating link between longevity and cold stress, you learn that stepping outside the constant comfort of air conditioning and heaters, and instead getting frequent exposure to temperature fluctuations such as cold air, snow, rain, sun, heat, and other environmental variables can increase stress resilience, burn more calories, increase cardiovascular performance, and get you more fit quickly.

Now, the relatively new article, “Natural environments, ancestral diets, and microbial ecology: is there a modern “paleo-deficit disorder”?” highlights research from as early as the 1960s, which shows that early-life experience with microbiota and other bacteria found in outdoor situations, along with environmental stress, can actually positively influence longevity and health outcomes. The author recognized the co-evolutionary relationship between microbiota and the human host. The article points out the fact that there is lower health, more anxiety and depression, and increased incidence of immune-related disease in developed nations that have become too sanitized—specifically too sanitized with respect to not being outside around dirt, trees, animals, and other natural areas of “microbial ecology” (which, by the way, is far different than manmade bacteria and synthetic toxins and chemicals in gyms.

In a 2010 Japanese study of shinrin-yoku (defined as “taking in the forest atmosphere, or forest bathing”), researchers found that elements of the environment, such as the odor of wood, the sound of running stream water, and the scenery of the forest, can provide relaxation and reduce stress, and those taking part in the study experienced lower levels of cortisol, a lower pulse rate, and lower blood pressure.

This should all really come as no surprise. Scientists have long known that sunlight can lower depression, especially depression from seasonal affective disorder (SAD). A 2007 study from the University of Essex found that something as simple as a walk in the countryside reduces depression in 71% of participants. These same researchers found that nature therapy, also known as “ecotherapy,” and spending as little as five minutes in a natural setting, whether walking in a park or gardening in the backyard, can improve mood, self-esteem, and motivation.

Other health care professionals are also finding that being in a natural environment has numerous benefits for kids, and can combat the obesity, anxiety, depression, and other health issues that arise with “nature-deficit disorder.” In an article at WebMD, nurse Stacy Bosch of the Clark County School District in Nevada is cited as seeing many students who are overweight or have type-2 diabetes, and she notes that, more often than not, these kids spend very little time outside. To get the kids and their parents away from the TV or computer and increase their physical activity can help control weight and blood sugar, Bosch writes a prescription for the entire family to go to one into natural areas and simply take a walk.

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How to Exercise Outdoors

So now that you know that constantly being indoors in a gym may not be the best thing for your health and that being outdoors in nature provides you with a myriad of benefits, what are some ways you can start exercising outdoors? Here are five quick and dirty tips:

1.   Commute With Your Body

It always surprises me when folks drive just a few miles (or less!) to the gym so they can move when it would have been just as easy to move to the actual gym via bicycle or foot. Say you have a concurrent strength-endurance workout that involves running and lifting. Why not run to the gym, do your lifting, and run back? Too far? Allow me to introduce you to a novel machine called a bicycle, available for a quick rent or purchase anywhere in the world. It's rare these days that I use my truck at home for anything except hauling alfalfa for the goats or transporting a paddleboard, and also rare for me rent a car or use public transport when I travel. If I can engage in low-level physical activity all day long, including commuting with my body, it's that much less time I need to spend in the “cardio section” of the gym. Of course, you can always step up your commuting a notch with a weighted vest or weighted backpack.

2.  Find A Park

Anytime I’m traveling, I use Google maps' “find nearby” function to find the nearest local park (those are the big green patches on the screen) where I can do dips and push-ups on park benches, pull-ups from bars or tree branches, mini-workouts at the children's play area if it doesn't creep out the parents too much, a jog or run on the park trails, yoga in a quiet grassy area, or skips, hops, bounds, and sprints on a wide-open section of grass. One of my standby workouts? Run the circumference of the park, choose 3 exercises (e.g. push-up, burpee, lunge jump), do a high-rep set of all three, then run again.

3.  Use Nature As A Gym

In my article “Strongman Workouts for Fat Loss, Muscle Gain, and Performance,” I give you plenty of backyard and outdoor gym ideas, including:

• Make A Sandbag: I made my sandbag in about 30 minutes by purchasing a couple military duffel bags off Amazon, then putting pea gravel into plastic contractor bags, and putting the gravel-filled plastic bags into the duffel bags. Here are some good sandbag instructions.
• Get A Tire: I pulled into my local tire store and asked them if they had any old heavy tires they didn't need anymore. They gave me four of them for free, and even offered to help toss them into the back of the pickup truck for me! Afterward, I realized that a true Strongman probably would have put the tires into the truck himself.
• Hunt Down A Tree: Whenever I go on a hike, I make it a goal to find at least one log and carry it for a little while, either overhead or clutched in my arms or on my shoulders. But the past couple times, I’ve taken the heavy logs home so that I have them in my backyard for easy access.
• Find A Rock: My nearby river has some nice big rocks that I also took home to my yard. These kind-of-big river rocks are smooth and don’t give you as many scrapes and cuts as some of the rougher varieties.
• Push A Vehicle: Have a manual car or truck, and a driveway or access to a big empty parking lot? Simply put your vehicle into neutral and get ready for the workout of your life.

Want even more? Check out my friend Zach Evenesh's excellent book “The Encyclopedia of Underground Strength and Conditioning“, and also my Cropfit article, in which I talk about how a nineteenth-century farmer would be pushing, pulling, lifting, hoisting, bending, twisting, and moving all day long. While you may not have a farm, and you may not have a desire to build a giant wooden barn or till a field, you can still inject a little extra fitness in your daily routine with activities such as:

-Going to your local hardware store, buying a rope, attaching it to a tire or cinder block, and practicing dragging an object in your driveway or backyard…

-Planting a small patio garden and going outside (moving!) to water, pick, plant, and care for your plants…

-Going to a park that has a safe and sturdy wooden fence and climbing over fences, under fences, or even balancing on top of fences…

-Finding a heavy river rock and carrying it up or down a hill, or (more practically) building a wall, firepit, gardening area, etc. in your backyard with large rocks…

You get the idea.

4.  Hike

Hiking solo is one of my personal methods to recharge and reboot my body and is also a great activity to do with friends or family, since it generally allows you to socialize, plant forage, get nature therapy, etc. while you’re exercising. With a little research about your local area, you can often find short hikes that offer good scenery without too much difficulty or special equipment. Contrary to popular belief, hiking doesn't need to be a passive, easy walk. More difficult hikes with weight packs, boulder scaling and even stops to carry heavy rocks or logs can provide you with an extreme fitness challenge that’s just as tough as any hard class you might take at a gym. My #1 go-to app for hunting down hikes just about anywhere is AllTrails.

5.  Find Water

From swimming to kayaking and canoeing to paddleboarding, swimming in rivers, lakes, or the ocean gives you the benefits of cold thermogenesis, a non-weight bearing form of exercise, and exposure to even more elements of nature—without all the chlorine and mold issues I talked about above. Beach workouts that involve sprints, burpees, push-ups, mountain climbers, lunges, and squats can easily be combined with forays into the water for freestyle and underwater swimming (for these type of workouts, a good underwater .mp3 player can spice things up a bit).

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Exercise & Air Pollution Outdoors

Of course, no consideration of exercise and air pollution would be complete without addressing air pollution outdoors, which in some major metropolitan areas can be just as concerning as indoor air pollution. Just recently, the American Lung Association published its report on the latest measurements of soot particles and ozone in the air for almost 1,000 countries and cities in the United States.

The results come as no surprise, especially for measurements in major cities like Los Angeles. In fact, LA has been found to be one of the most polluted in the U.S., and not too far behind are the highly urbanized cities of Houston, Washington, New York, Cincinnati, and Philadelphia. On the other hand, cities in North and South Dakota, as well as Palm Beach, Fla., are considered cleanest as of the moment.

Whether you live in a polluted city or not, you’ve surely had to make do with working out along busy polluted roads at some point in your life. Whether you’re a serious athlete or a recreational cyclist or runner, it’s but prudent to educate yourself if working out in polluted areas causes damage to your lungs and your health overall (including your brain – just recently CNN reported on a major study showing the links between cognitive decline and air pollution now affecting 95% of humans worldwide!)

According to a 2004 Australian review of pollution studies worldwide, during exercise, even a very minimal concentration of air pollutants can damage the lungs. Said harming effect to the lungs is as severe when exposed to high concentrations of soot and air pollutants when not working out. The researchers, therefore, concluded that individuals who work out outdoors, especially in highly polluted areas, should be worried about their health.

This happens because harmful particles from the air can get past the nasal hairs, the body’s first line of defense. Ultimately, these particles end up in the lungs thus causing inflammation and irritation. These particles sometimes end up in the bloodstream as well. When this occurs, the risk for heart attack and stroke then increases. So since working out means you’ll have to breathe deeper, then more of these particle pollutants get to pass through your nasal filtering.

Yet another study that was featured in the New England Journal of Medicine concluded that females who live in areas with high levels of air pollution in the form of soot have a higher likelihood of dying from heart attacks as compared to females who lived in cleaner air. Said researchers then concluded that soot particles are very harmful, most especially to athletes who take in higher concentrations during exercise.

A similar study at the University of Edinburgh was conducted in 2005 as well. Healthy subjects were made to exercise for 30 minutes on stationary bikes inside a laboratory that had been piped-in with diesel exhaust fumes at levels similar to that of a busy highway during rush hour. Researchers then found that the subjects’ blood vessels were affected in that the latter’s ability to distribute blood and oxygen to the muscles were negatively compromised. The subjects’ levels of “tissue plasminogen activator,” which are naturally-occurring proteins that function by dissolving clots in the blood, significantly decreased as well. Because of these findings, the researchers concluded that working out along polluted roads may possibly set in motion the preliminary stages of heart attack or stroke.

But new research offers some glimmer of hope to athletes and exercise enthusiasts who have no choice but to exercise in polluted urbanized areas. A recent study entitled “Anti-Inflammatory Effects of Aerobic Exercise in Mice Exposed to Air Pollution,” which was featured in the journal Medicine and Science in Sports and Exercise, an extended timeline was utilized to study the effects of air pollution during exercise. It’s crucial to note that this latest research is quite unlike the previous studies wherein the latter only measured the negative effects immediately after the exercise. For this most recent research, two groups of laboratory mice were utilized. Both groups were subjected to regular doses of diesel exhaust fumes for five straight weeks. The first group, though, did not exercise, while the second did. Researchers found that an alarming spike in lung inflammation and free radicals were seen in the mice that did not perform the exercise. Astonishingly, the other group of mice, the ones that were made to exercise while exposed continually for five weeks to diesel exhaust fumes, seemed to have undergone changes that allowed their bodies to combat the harmful effects of the pollution.

These findings had researchers conclude that long-term aerobic exercise may just offer protective effects, potentially due to the body’s ability to naturally produce antioxidants that are crucial for combating the harmful effects of pollution. Granted, the study was conducted on mice. So what about the effects of pollution during exercise on humans?

It’s no secret that the higher the air pollution in the area, the higher the hospital admissions for patients seeking relief or treatment from cardiovascular and respiratory issues as well. But on the other hand, the health benefits of exercise seem to more than just balance out the harmful effects of air pollution. To demonstrate, a 2010 study in the Netherlands utilized epidemiological data and estimated that short daily trips using a bicycle in polluted cities would take away between 0.8 to 40 days from a person’s average span of life. However, said researchers also found that the additional exercise would lengthen an individual’s lifespan by three to 14 months. It then appears that working out is indeed better as compared to no exercise at all when living in an urbanized and polluted area.

Yet another study was conducted at the University of British Columbia’s Environmental Physiology Lab. The research utilized two groups of individuals for seven straight weeks. The first group was made to cycle at various intensities while exposed to diesel engine exhaust. The second group, meanwhile, performed a similar activity though in an environment with clean, filtered air. The results provide hope as the subjects made to cycle in polluted air appears to have adapted their bodies, and in fact, showed signs of combating the harmful effects of pollution the way that the mice in the previous study did.

Of course, additional studies have to be conducted to truly establish as fact the anti-inflammatory effects of exercise against pollution. But the limited number of research available to us right now may help allay your concerns, as it appears going out to exercise is better than no exercise at all when living in a polluted area.

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Tips For Stopping The Body & Brain Damage From Air Pollution

As you discovered above, your body may indeed have a built-in mechanism to protect itself from the harmful effects of air pollution, but it’s prudent to take additional steps to lessen the damage. So include the tips below if you exercise outdoors near polluted roads or indoors in polluted gyms.

1. Know When to Exercise

As you probably already know, the quality of air is most compromised when temperatures are at the hottest. During high temperatures, the sunlight, as well as the heat, essentially charge up the air along with all the chemical compounds that are present in the atmosphere. This concoction then combines with the nitrogen oxide naturally existing in the air, resulting in smog which is a harmful combination of smoke, soot, and chemical fumes. Since this is the case, it would then be prudent to time your workouts during the cooler mornings or during early evenings.

2. Avoid Working Out Along Roads

Steer clear of roads, particularly busy streets, as these areas tend to have a higher concentration of airborne pollutants. Simply choosing to run, walk, or cycle a few meters from the road can do wonders. Of course, altogether avoiding busy roads is by far the most ideal if you truly want to minimize your exposure to airborne pollutants.

3. Educate Yourself About Your Community’s Air Pollution Levels

Prior to planning your major run or bike sessions, opt to check airnow.gov first. Here you will find the latest EPA air-quality forecasts for all the major cities in the U.S. This way, you can schedule your workouts during the least polluted hours of the day.

4. Don a Mask

Wearing a filtration mask is a smart move as well. Athletes who wear filtration masks during their workouts in polluted urban areas tend to have fewer incidences of “pollution nausea” as compared to those who don’t wear masks. Sure, you may look like an Asian bird flu hypochondriac, but if you're going to be running alongside traffic, it's a small price to pay to avoid the adverse effects of air pollution.

5. Take Antioxidants Regularly

Though your body produces its own antioxidants, the latter may not be enough to combat the daily stress that your body is subjected to due to exposure to pollutants. To help your body fight against harmful free radicals, opt to boost your intake of antioxidant-rich fruits like cherries, pomegranates and blueberries, as well as dark vegetables like kale, bok choy, swiss chard and purple cabbage, bitter herbs and spices such as rosemary, turmeric and curries, and stinky sulfurous compound such as garlic, onions, broccoli and cauliflower.

6. Breathe Through Your Nose Whenever Possible.

As you learned in my big article on breathwork, the hair, turbines and small bones in your nasal passages act as a natural filter.

7. Use Plants

To ensure that the air circulating in your home or office is pure, clean and filtered, plant or place natural air-cleaning plants in as many rooms of your home as possible. NASA actually did a Clean Air Study and found that plants such as Peace Lily, Boston Fern, English Ivy, Areca palm and other easy-to-grow greens can absorb toxic chemicals through their leaves, their roots, and even the soil that they rest in, removing many of the toxic vapors that may be lurking about our environment, including benzene, formaldehyde, and trichloroethylene. Of course, an added benefit of plants is the de-stressing nature therapy effect, along with the beneficial aromatic polyphenols they emit, very similar to an essential oil diffuser.

8. Use Air Filters

Install a HEPA (High Efficiency Particulate Arrestance) air filter in your home. A good HEPA filter can remove almost 100% of particles, and also the vast majority of toxic ozone, volatile organic chemicals and gases. For a standalone unit, I recommend one or several “AirDoctor” HEPA filters placed throughout your home. The filter it contains is 100 times more effective than ordinary HEPA filters and is able to capture 99.99% of the most dangerous ultrafine particles. The dual action carbon/gas trap/VOC filter removes dangerous ozone, gas and volatile organic compounds like formaldehyde, and also has a negative ion generator. If you want to spend more money, you can upgrade to another standalone unit: a “Molekule”, (use code: BEN for $75 off) which contains nanotechnology that destroys pollutants at the molecular level. Many harmful pollutants such as viruses and some smaller VOCs are smaller than 0.3 microns and even an AirDoctor HEPA filters can’t remove all of them. Molekule’s technology, called “Photo Electrochemical Oxidation (PECO)”, works at the molecular level to eliminate all indoor air pollution, and is is able to destroy pollutants 1000 times smaller than HEPA filters. Finally, if you don’t want Air Doctors or Molekules spread all over your house you can, like me, install a HEPA filter with an ozonator and negative ion generator in the central air duct of your home. For this, I use a brand called “AllerAir”. 

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Summary

So that's it: don't stop exercising – even in gyms and polluted areas. Just do as much as you can to mitigate the damage, and if you ever have the option to exercise outdoors in fresh, clean air, do that instead.

If you happen to dig this article and love all things outdoors, please feel free to share it with others and to leave all your comments and question below – I promise to reply!

In addition, for even more health, fitness and biohacking tips from yours truly, check out the latest edition of Outside Magazine (yes, that's me on the cover, freezing my ass off in a giant ice bath the photography crew so kindly rigged up for me).

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Additional References:

-Physical Activity and Air Pollution Exposure

–Ambient air pollution and adult asthma incidence in six European cohorts (ESCAPE)

–Fine Particulate Air Pollution and Mortality in 20 U.S. Cities, 1987–1994

–Exposure to indoor air pollutants during physical activity in fitness centers

–Volatile Organic Compounds (VOCs)

–Fungal DNA, allergens, mycotoxins, and associations with asthmatic symptoms among pupils in schools from Johor Bahru, Malaysia

–Particulate Matter (PM) Pollution

–Indoor Air Quality (IAQ)

–Exposure to indoor air pollutants during physical activity in fitness centers

–Health Effects due to Indoor Air Pollution

–Characterization of coarse particulate matter in school gyms