A 2010 study that examined body image implications in relation to time spent in nature found that spending more time outside—away from mirrors, media and other stimuli that might make you feel self-conscious about your appearance—may help to increase confidence by silencing negative thoughts.
“Spending too much time away from nature triggers the primal alert systems in our brain,” says Sisson. “Car horns, traffic jams, flashing lights, the drone of the overhead lighting in our offices, the permaglow of the computer screen, the stale interior air… Our brains interpret these sensations and situations as stressors. And if we spend most of our time immersed in such environs, we’re subject to a constant level of chronic, low-level stress that increases inflammation, inhibits our immune system, elevates the stress hormone cortisol, and puts us permanently on edge.”
Serotonin is a hormone that affects our feelings of wellbeing and happiness. Decreased serotonin levels are often associated with symptoms of depression. A 2007 study in the Journal of Psychiatry and Neuroscience which reviewed methods for increasing serotonin in the human brain without drugs suggests increased exposure to bright light, such as the sun, as an effective approach.
One 2014 study associated exercising outside with better stress management. “The bench mark for health is the ability to relax. Relaxation is best done under a tree,” says Eoin Finn, a renowned yogi with more than 20 years of yoga experience and a “Blissologist” who spends more than 15 hours a day outside. Sisson adds, “Going outside is a reset of sorts. It quiets the brain and dampens the stress response. This is because our brains are wired to be around trees and dirt and sand and running water and to perceive expansive vistas and breathe fresh air.”
“So many people try to tune [nature] out,” says expert running coach and outdoor enthusiast Eric Orton. “They think, ‘I just want to get my workout over with.’ I love music just as much as running, but I can’t remember the last time I listened to music while running because I want to get out and experience nature. Throw everything away and just be aware of your surroundings. I think awareness is big part of being an athlete. Be aware of what’s going on. We can have an adventure in our own minds wherever we run as long as we are aware of what’s going on.”
“Vitamin D is intimately involved in dozens of vital physiological processes, from immunity to cancer prevention to testosterone production to bone density maintenance to cavity prevention,” says Sisson. “Heck, it even protects the skin from ultraviolet damage and inhibits the growth of melanoma cells. Sunburns may increase the risk of skin cancer, but smart sun exposure from consistent, moderate amounts of time out in the sun reduces it. If we don’t go outside, we don’t make the vitamin D we require to stay optimally healthy.”
Dr. Jeffery Benabio, a board-certified dermatologist and the Physician Director of Healthcare Transformation at Kaiser Permanente says that 10 to 15 minutes of sun exposure without sunscreen three times a week is a sufficient amount. “Longer than that and you’re simply increasing your risk for skin cancer,” he said. “Very fair-skinned people can produce enough vitamin D within five minutes before they’ll start to burn, and it’s also important to remember that vitamin D is produced through our diet and incidental exposure to the sun, like when we walk to and from our cars for example.”
Benabio also noted that safe amounts of exposure to sunlight can help regulate your sleep. Sunlight helps to regulate your circadian rhythm, which regulates when your body feels sleepy or awake throughout the day.
A 2014 study that reviewed the physiological and psychological outcomes of indoor cycling compared to outdoor cycling found that participants who rode outside exercised at a higher intensity despite similar environmental conditions and perceived exertion.