Eating for Exercise: What, When, Why and How Much?

Eating the right foods before and after you exercise can make the difference between a killer workout and one that just kills you.

Like a car, your body needs fuel — the right kind in the right amount — in order to work properly. “You can’t put 10 miles worth of gas in your car and expect to drive for 30 miles without breaking down,” reasons Alissa Rumsey, a registered dietitian, nutritionist, and certified strength and conditioning coach in New York City. “The same goes for your muscles.”

For that reason, Rumsey recommends not working out on a completely empty stomach. She suggests timing your exercise for three to four hours after a meal or within an hour of a small snack that provides some carbohydrate and protein (like half a banana with a teaspoon of peanut butter). And skip anything that’s too high in fat or fiber — both digest slowly, which can interfere with your workout.

Staying hydrated is also essential. “Water is ideal — make sure you get 8 to 16 ounces an hour before a workout, keep sipping while you exercise, and then replenish with another 8 to 16 ounces in the hour after you finish,” says Rumsey. If you’re sweating excessively, you might opt for a salty snack with your post-workout water, or a sports drink, to help replace any lost electrolytes.

And if you’re trying to lose — or at least not gain — weight, be smart about your balance of food and exercise. “A lot of people overestimate the number of calories they’re burning during a workout,” says Rumsey. “Exercising doesn’t give you free rein to eat as much as you want.” You will still want to eat something to fuel your workouts and help muscles recover, but be mindful of needing to keep your portions in check.

After a workout, it’s important to eat something 20 to 30 minutes after you finish exercising. You’ll want a balance of protein to help repair muscles and carbohydrates to replenish their glycogen stores. Here are the best recovery-enhancing snacks to have after doing each of the following workouts.

High-intensity interval training (HIIT): The high-energy cardio of this type of workout will deplete your muscles’ glycogen stores, so you’ll want a little extra carbohydrate — balanced with some protein — afterward to fill them back up. Try crackers with peanut butter and banana slices.

CrossFit: A workout that focuses on heavy lifting will leave your muscles hungry for protein. Try Greek yogurt with nuts, chia seeds and berries mixed in.

Yoga: A longer, lower-intensity workout will utilize more fat stores than glycogen, so you don’t really need to worry about restoring carbohydrates after class. You’ll still want to refuel, but your snack can be something small — like a piece of fruit or a handful of nuts.

Sally Wadyka is a Boulder, Colorado-based journalist who writes about nutrition, health and wellness.

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