When: The Scientific Secrets of Perfect Timing

by Daniel H. Pink

Lose weight: When we first wake up, having not eaten for at least eight hours, our blood sugar is low. Since we need blood sugar to fuel a run, morning exercise will use the fat stored in our tissues to supply the energy we need. (When we exercise after eating, we use the energy from the food we’ve just consumed.) In many cases, morning exercise may burn 20 percent more fat than later, post-food workouts.1 Boost mood: Cardio workouts—swimming, running, even walking the dog—can elevate mood. When we exercise in the morning, we enjoy these effects all day. If you wait to exercise until the evening, you’ll end up sleeping through some of the good feelings. Keep to your routine: Some studies suggest that we’re more likely to adhere to our workout routine when we do it in the morning.2 So if you find yourself struggling to stick with a plan, morning exercise, especially if you enlist a regular partner, can help you form a habit. Build strength: Our physiology changes throughout the day. One example: the hormone testosterone, whose levels peak in the morning. Testosterone helps build muscle, so if you’re doing weight training, schedule your workout for those early-morning hours.