It was 50 years ago that the Wilderness Act—which protects over 100 million acres of U.S. land—became law.

In the last half century, millions and millions of Americans have enjoyed National Parks.  But we often forget that National Parks aren’t just about preserving the nation’s natural beauty or the environment – they are also vital for protecting the future health of the nation. 

These parks are places specifically set aside where Americans can go and be active.  They offer safe, spectacular opportunities for walking, hiking, biking, climbing and playing.

And right now, it’s more important than ever to give Americans more places to be active.  We have a serious health crisis.  More than two-thirds of adults and one-third of kids are overweight or obese.  Activity is half of a healthy energy balance equation, but less than half of children (ages 6 to 11), less than 30 percent of high schoolers, and less than half of adults get the recommended amount of daily physical activity.

According to the U.S. Centers for Disease Control and Prevention (CDC), Americans who are physically active typically live longer and are at lower risk for serious diseases like heart disease, type 2 diabetes, depression and some forms of cancer – and it can even help students improve how they do in school.  Physical activity is the real life fountain of youth – it helps give us more energy, reduces stress and can even help you feel better.

National Parks are some of the most amazing places we have in this country to be active and free.  I’m lucky to live in Washington, D.C. – I see the activity in National Parks in live action every day – from Great Falls to Meridian Hill Park to the National Mall.  Kids are running, cyclists are pedaling, tourists are exploring and people are stopping to smell the flowers. 

And, National Parks are not just good for our health and the environment, they are also good for the economy. For instance, across the country in Washington state, 7 million tourists visit National Parks and provide around $400 million to the local economy.

But, sadly, instead of expanding and preserving our parks – Congress has protected just one new area in the past five yearsthe lowest rate we’ve seen since World War II –  and as much as four million acres of park land are inaccessible. And, according to the National Parks Service, the unmet need for outdoor recreation facilities and parkland acquisition at the state level is $27 billion.

This generation of children may be the first in American history to live shorter, less healthy lives than their parents.  But, by preserving land and creating parks, we’ll expand the opportunities for kids and their parents to be active and healthy – handing down a legacy of a better environment, better health and a better future all around.

Levi, PhD, is executive director of the Trust for America’s Health.