Modern life can feel like a to-do list in a never-ending loop - if we let it. Wake up, go to work, grocery shop, prepare food, do household tasks, wake up, go to work… Some days you might get to throw in an exciting change of pace like filling up the car with gas or picking up the dry cleaning.

Too often, exercise is just another box that must be checked. There is no joy in simply adding a trip to the gym or a run on the treadmill to the rotation.

But what if there is a way to add exercise that helps you feel more revitalized and energetic, and less tense, confused, angry, or depressed?

That’s exactly what research shows exercising in a natural environment does. In addition, adults who exercised outdoors at least once a week reported more minutes of moderate to vigorous physical activity than those who exercised indoors only. Not only does getting outside make you feel better, you also work harder. Moving that run outdoors makes a difference.

Of course, this research comes at a time in history when we spend less time outdoors than ever. We sit at desks, stare at screens, and travel in cars that we park in garages.

This is the lament of Richard Louv, author of Last Child in the Woods, Saving Our Children from Nature-Deficit Disorder. The effects of limited outdoor activity certainly have a negative impact on our youth. As Louv points out, we’ve had the greatest increase we’ve ever seen in organized sports in recent years. Even so, childhood obesity has doubled in children and quadrupled in adolescents in the past 30 years.

You simply can’t replace a lifestyle of active outdoor play with a few organized practices a week and hope for the same results.

As critical as this issue is for children, it’s just as important for us adults. “Recreational sitting” – sitting in front of screens for pleasure during free time, is associated with increased mortality and cardiovascular disease regardless of physical activity. So even if you are killing it at the gym for an hour a day, all that time watching Netflix is still going to get you. It’s not an exercise issue; it’s a lifestyle issue.

Paleo diet guru Mark Sisson taps into this idea with his recommendations for exercise. They include getting outside, walking long distances, sprinting once in a while and moving heavy things around. This mimics the physical activity he imagines a caveman would have naturally pursued in the course of his day. Think about it. They walked long distances in search of food, occasionally ran from a predator, and moved heavy logs and rocks to create shelter.

Whether you subscribe to the Paleo philosophy or not, it’s hard to argue with the idea that man lived this way until very recently in human history.

And now mainstream physicians are getting in on the game. One of the more entertaining doctor-authors, James Hamblin, explains in a piece for The Atlantic, why doctors now prescribe outdoor time. They even get down to specifics including which park to visit for how long and how often.

It’s not clear where the benefits of spending time outdoors come from. Some credit the concept of biophilia – our natural affinity to nature. Throughout history, humans relied on observing and understanding nature for survival. Those with the most affinity for it were more likely to survive, and thus more likely to pass those characteristics on in the evolutionary process.

Others suggest more specific mechanisms, such as increased exposure to natural light and its impact on vitamin D. Still others point to exposure to microorganisms that boost the immune system, protect against depression, and have other beneficial effects.

The bottom line is we don’t really know why it works. But we do know getting outside and moving about in nature does seem to make us healthier and happier.

So, as your mom always said, go outside and play.

Amy Rogers MD is not a practicing physician and nothing written here should be taken as medical advice from either Amy or AssetBuilder. Medical decisions should be made with care in consultation with your health care provider.