When I'm getting ready for travel — I make sure five specific movements stay in my week, every week. The point is that on day two of the trip I'm not trying to walk off the airplane out of my hips, or compensating for a sore back from a long flight, or skipping a hike because my calves are cramping. The point is to actually be in the trip, not negotiating with my body through it.

On Crescent Island in Lake Naivasha, there are no large predators. So when you walk among the giraffes, zebras, wildebeest, and eland, no one’s heart rate is up — yours included. They graze. You walk.

I grew up outside a small university town in Connecticut, on a dead-end road far from any traffic. Our yard had trees, a vegetable garden, and a river running through the back. In summer the leaves were thick enough that we couldn't see the neighbors' houses — we were inside nature, not beside it. The sounds were birds and water.

I've been finding my way back to that ever since. Time present in nature is a cure — it soothes what aches in the soul. It's also prevention: real, measurable, physical change in the brain and body.

Since having children — and then watching them move out into their own lives — the first time I really noticed I was on vacation, it was day two…

New Year's resolutions: about 80% of Americans make them, but only about 8% actually achieve them. That's not because we lack willpower or commitment—it's because we're setting ourselves up for failure from the start.

After 40 years of teaching movement and working as a behavioral change specialist, I've seen this pattern play out hundreds of times.