On lazy afternoons back when I was a kid, my dad would announce, "Let's go for a walk"... and my sister and I would run and hide. Anything was better than going on a boring walk! Now, much as I notice that I grip the steering wheel the same way my dad used to, I've also developed his appreciation for walks.
Walking is gentle exercise. You're operating below the aerobic threshold, which the mitochondria in your muscle cells love. You're neither sitting nor standing still, which your back loves. You're getting sunlight, which your skin loves. You're setting your circadian clock, which makes falling asleep at night easier. You're out in nature reflecting on your thoughts, which your meditative mind loves.
I started taking walks at lunchtime because I had a desk job that made me crazy. If you have a similar situation take advantage of it, and head out for a walk. The office will still be there when you get back, but you'll be a little different... for the better.