If you do a high-intensity workout lasting an hour or longer, it's crucial to eat something afterwards, says Amy Campbell, fitness competitor, two-time NFL cheerleader, and former Ms. Fitness Universe.
"Within the first 45 minutes post-exercise, there is a “metabolic window," she says. During this time, your body's ability to utilize protein, carbohydrates, and fat instead of storing it all is at its peak.
"Eating a carb-and-protein mix at this point will maintain muscle, replenish glycogen stores, and reduce the amount of fat your body stores. Some examples may include: peanut butter sandwich, yogurt with fruit, bagel with cream cheese, or a handful of nuts (almonds/walnuts) with an apple and reduced-fat string cheese. Even an 8-ounce glass of nonfat chocolate milk is a great idea if you don’t have something more complex available," Campbell says.