Hit the trails in Western North Carolina any day of the week and you’ll find hikers, runners and mountain bikers enjoying a workout. But exercising outdoors may have benefits that extend beyond burning calories.
“Think about how we evolved for hundreds of thousands of years versus how we live now for a very short period of time,” says Aubri Rote, exercise physiologist and associate professor in health and wellness at UNC Asheville. “We obviously exercised outdoors for so much of our evolution in time here on Earth — we evolved to [exercise outdoors] and to do it indoors is certainly different,” she says.
It may seem like common sense, but science shows that there are quantifiable benefits to exercising outside. A 2011 study in Environmental Science and Technology comparing the effects of outdoor to indoor exercise found that exercising in natural environments was associated with higher levels of revitalization, energy and positive engagement as well as decreases in tension, confusion, anger and depression. Participants also reported greater enjoyment and satisfaction with outdoor activity and expressed greater intent to engage in the activity again.
Rote warns that although there is a growing body of evidence suggesting there are benefits to exercising outside, the topic is relatively difficult to study. “The brain is still a black box,” she says. “But we know that being outside is calming in general.”
There’s no doubt about the benefits of exercising outdoors in Miranda Peterson’s mind. Peterson is the owner of Namaste in Nature, an Asheville-based business that leads clients on hikes and conducts yoga classes in nature. Peterson says she decided to start a business encouraging people to exercise outdoors after taking a sabbatical from work and school. “I noticed such a difference in spending more time outside. It really improved my mental and physical health,” she says. Her clients tell her they experience the same: “After three hours outside, they say they feel amazing,” says Peterson.
Stepfanie Romine, a Hendersonville-based American Council on Exercise-certified health coach, says there are a variety of physical and mental benefits to exercising outdoors. “The first benefit to exercising in nature is that outside is free,” says Romine. “That’s not just a popular hashtag. Anyone can go outside at any time and get the benefits of fresh air. I encourage people to get outside whenever possible,” she says.
“When you get on the treadmill and you set your speed and incline, you’re running at that speed and incline for whatever time period you’ve selected. There are no curveballs thrown your way. You can tune out and stare at the TV or phone. You aren’t training your body to stay present when you are working out indoors,” she says. “We also have a different stride when we run and walk outdoors. We flex the ankle more, which is good for us.”
Other benefits of exercising outdoors, she continues, are burning more calories from wind resistance and building physical resilience.
For example, exercising outside builds resilience to the weather, she notes. “We are really fortunate here in Western North Carolina to live in a temperate climate. If you are willing and able to go outside year-round, you will acclimate to the wind, heat, rain and cold.” We’re also less likely to pick up colds or flu outdoors in the wintertime, she says, when recycled air at your fitness facility may carry germs and nasty bugs.
There are also benefits associated with exercising in natural light. “When you exercise outside, you expose yourself to sunshine, more vitamin D and more oxygen,” says Rote.
Research reported on the Scientific American website in 2009 indicates that “three-quarters of U.S. teens and adults are deficient in vitamin D, the so-called ‘sunshine vitamin’ whose deficits are increasingly blamed for everything from cancer and heart disease to diabetes.”
Studies also show that the benefits of exercising outdoors extend beyond the physical. Outdoor exercise improves mood and self-esteem — both indicators of mental health. Romine notes that it’s not clear whether effects are from “the vitamin D exposure from sunshine, the connection to nature, the freedom or some combination thereof.” The same studies also showed that the presence of water generates even greater mood and self-esteem boosting effects. Men and women experienced similar improvements in self-esteem, and those with mental health issues showed some of the greatest self-esteem improvements.
A 2013 study in the International Journal of Environmental Research and Public Health showed that higher levels of green space are associated with lower levels of perceived stress and a decline in the stress hormone cortisol.
Rote says that even seeing scenes of the outdoors while indoors is relaxing: “It has a calming effect and a good psychological benefit.”
While the benefits of exercising in nature are well-documented, exercise may not be required to reap some benefits. In Japan, the practice of shinrin-yoku, also known as “forest bathing,” produces health effects from taking in the forest through the senses.
A study conducted in 24 forests across Japan showed spending time in forests rather than city environments produced reductions of the stress hormone cortisol, a lower pulse rate, decreased blood pressure and increased activation of the parasympathetic nervous system.
The practice of “earthing,” also called grounding, “refers to the discovery of benefits — including better sleep and reduced pain — from walking barefoot outside or sitting, working or sleeping indoors connected to conductive systems that transfer the Earth’s electrons from the ground into the body,” according to a 2012 review article from the Journal of Environmental and Public Health.
The article states that “emerging evidence shows that contact with the Earth — whether outside barefoot or indoors connected to grounded conductive systems — may be a simple, natural and yet profoundly effective environmental strategy against chronic stress, autonomic dysfunction, inflammation, pain, poor sleep, disturbed heart rate variability, hypercoagulable blood [abnormal blood coagulation] and many common health disorders, including cardiovascular disease.”
The review concludes: “Research done to date supports the concept that grounding or earthing the human body may be an essential element in the health equation along with sunshine, clean air and water, nutritious food and physical activity.”
Studies have shown that there are benefits to touching the Earth, even during sleep. A 2007 study in the Journal of Alternative and Complementary Medicine showed that connecting the human body to the Earth during sleep “normalizes the daily cortisol rhythm and improves sleep.”
“The Earth has a slightly negative charge,” explains Rote. “Throughout the day we build up somewhat of a positive charge, especially if we are creating free radicals which, if they are in too-large amounts, have been shown to be related to chronic inflammation.” Chronic inflammation has been linked to a growing number of illnesses, including cardiovascular disease and diabetes.
The idea of grounding, says Rote, is that if we have more physical contact with the Earth and spend more time outdoors, we can harness the negative charge and neutralize the positive charge that builds up in our bodies throughout the day.
As we enter the height of summer, Romine says, there’s no better time to take your workout outdoors, stressing that “human beings are meant to get outside.”