Q: I never know if I should eat before or after working out. Which one is it?
A: Eat afterward. Most of the fuel you use during exercise doesn’t come from the food you’ve recently eaten. It comes from the carbohydrates (called glycogen) and fat stored in cells in your muscles, liver, and elsewhere. The glycogen and fat work in tandem to give you enough energy to power through one or two hours of intense exercise—more than enough time for most people.
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But if you tend to feel light-headed during a vigorous workout (blood-sugar levels fall during the first 20 minutes of exercise), eat a small 150-calorie snack about 30 minutes prior to your session. Try easily digested carbohydrates, like juice, a banana, or a bagel (but avoid whole-wheat varieties, which are digested more slowly, since they contain high amounts of fiber).
After a solid, heart-pumping workout, your body enters what is known as “the golden hour,” when your muscles absorb the most nutrients and when glycogen is replaced most efficiently—but only if you eat a little something. If you don’t take advantage of this brief window with a light snack, your body may not recover as quickly and you could feel a bit sluggish the next day.
Most experts suggest a postexercise meal consisting of protein and carbohydrates, since studies show the addition of protein helps your body absorb carbohydrates more efficiently after exercise. Try a peanut butter sandwich on multigrain bread or yogurt topped with granola. (Leave the raw eggs to the guy in the muscle shirt.)