Eat, get back to the desk (check email or some low intensity stuff), then about 30 min later, go for a walk. Get out of the building and into sunlight for a min

Eat, get back to the desk (check email or some low intensity stuff), then about 30 min later, go for a walk. Get out of the building and into sunlight for a minimum of 15-20 minutes. Hot, cold, doesn't matter. Get out and walk.