For many professionals, finding an hour for the gym is about as feasible as finding an extra day in the week. There are deadlines, family obligations, late-night calls and the small matter of getting enough sleep. That is why “exercise snacks” – or micro-workouts – have become so appealing. Rather than reserving exercise for a long session, the approach breaks activity into short bouts: a brisk climb up stairs, a few squats between meetings or an interval session squeezed into a lunch break. The...