Text by Maridel Reyes
Picture the most relaxing place on the planet. Chances are, you didn't imagine a concrete jungle. Whether it was a tropical island, a grassy field, or the top of a mountain, you probably conjured an image of unspoiled wilderness -- and for good reason. Humans are hardwired to seek out nature, says Jo Barton, a lecturer and researcher in sport-and-exercise science who studies the health benefits of "green" exercise at the University of Essex in England. "We were hunter-gatherers and farmers for 10,000 years, but we've been industrialized for only a few generations," she says. So, it makes sense that we feel our best in the great outdoors. In fact, studies have linked time spent in nature to more effective workouts, sharper minds, and even fewer sick days.
Green Your Exercise Routine
Just five minutes of low-impact outdoor exercise -- such as gardening or walking the dog -- may significantly boost a person's mood and self-esteem, Barton's research suggests. And the reasons are primal: Exercising in areas with water and woods made people the happiest because such spaces "signal the presence of two things humans need to survive: food and water," she says. This fosters an innate sense of security and calm.
Taking an exercise regimen outside can also make it more efficient -- and enjoyable. Outdoor workouts tend to burn more calories than similar routines indoors because nature provides a pleasant distraction, helping you work out for longer periods. "Our research has shown that subjects can run faster outside than inside, but they perceive the outdoor exercise to be less exhausting," Barton says.
Most people reach for a sugary snack or coffee to fight brain drain. But according to new research from the University of Michigan, spending time in nature will sharpen memory and focus more effectively. In the study, volunteers were given a memory-and-attention test and then told to take a walk in either a park or a city street. Afterward, they took the same test again. Subjects who strolled in the park performed 20 percent better than city walkers. That's because walking in a city turns on voluntary attention, the kind needed to focus on the task at hand. "Urban areas are noisy, and you have to pay attention so you don't get run over by a car or bump into another person," says Marc Berman, the lead author of the study and a research fellow in psychology. Voluntary attention is limited and fatigable, so when you shift to involuntary attention, the kind that's activated by being in nature, it gives your brain a break, making you happier and more productive later.
Stave Off Sickness
Living close to green spaces may shore up the immune system. People who reside within half a mile from a park or a garden are less likely to get sick than those who don't, according to a review of studies from Deakin University in Melbourne, Australia. They are also more satisfied with their home, their job, and life in general. Researchers don't know exactly why proximity to green scenes is so beneficial but suspect it's related to reduced stress levels, which have been proved to contribute to a stronger immune system.
Even if you don't live near a green space you can still take advantage of nature's health offerings. A long weekend in the country, for example, can do wonders for your immunity. Scientists in Japan discovered that a three-day outing in nature led to a 9 percent jump in natural killer (NK) cells, a type of white blood cell that fends off bacteria, viruses, and tumors in the body, while a trip to a city didn't affect NK activity at all. What's more, the immunity boost lasted for up to one week after the outing. The benefit stems from inhaling essential plant oils called phytoncides, says Qing Li of Nippon Medical School in Tokyo, lead author of the study. Smelling these oils triggers the production of specific proteins that the body uses to make more NK cells -- and also boosts the activity of existing NK cells, he says. The tree huggers also had more energy and lower levels of the stress hormones cortisol and adrenaline, partly because of the phytoncides and partly because of nature's calming effects.