Mann spent two years traveling the world, practicing medicine in remote environments. He calls himself an advocate for holistic health. Asked if people should get time outside the way they get medicine, he said, "I absolutely think we should."
His case starts with history. "Humans, we really didn't evolve to live in these big structured communities with all the traffic and lights and noise," Mann said. "Our genetic roots are in the outdoors."
Sunlight helps the body, he said, including through vitamin D development. He pointed to links with improved cancer rates and decreased infections. Exercising outside adds physical benefits too.
The mental side has a lot of data behind it, Mann said. People spend hours on phones, tablets and TV, and he said screen time is directly linked to anxiety and other psychological conditions.
You don't need a trail to fix that. "It doesn't have to be a hike seven miles in the woods," Mann said. Based on literature and data, he said 10 or 15 minutes gardening, mowing the lawn or sitting on the back porch can yield significant benefits.