Performance Foods: What and When to Eat Before Your Next Workout

It's happened to the best of us: You head out for a run or to a class at the gym with just a bottle of water, and midway through your workout, you bonk. You hit the wall and feel lightheaded, weak, or just plain out of steam.

In fact, it happened to me this past weekend when I woke up just 30 minutes before an outdoor boot camp. I managed to grab a waffle out of my daughter's hand and nibbled on it as I sprinted up the hill to the park. I was doing fine until the instructor asked us to do two-leg jump ups on a rather high park bench. My brain said "yes," but my legs said "no" and ultimately, I had to sit out the drill.

[See Stay Fit Without Setting Foot in The Gym]

Exercising on an empty stomach is generally a bad idea, but It can be tough to figure out how much to eat before you work out and what types of fuel will be easy to digest. About the only thing worse than not having enough energy to get through a run or swim is having an unsettled stomach. And since so many of us are fitting in workouts during our lunch breaks and before picking up the kids, we often don't think about a recovery snack.

Here's my guide for everyday athletes on what to eat before and after your sweat sessions:

Pre-Workout

[See Facts and Myths About Fueling Up Before Your Workout]

People often ask me how far in advance they should eat before exercising. Generally, the answer is an hour. So if you're heading to a 7 a.m. spin class, fuel up at 6 a.m. Of course, when time is tight, you may be running out the door with nothing in your stomach. In that case, a good old banana is the best thing you can munch on. It's easy to digest, portable, requires no utensils, and you can down it quickly. I always have a bunch sitting in a bowl by my front door so they're easy to grab.

What should a pre-workout snack consist of? Ideally, it's a mix of carbohydrates with a bit of protein, totaling no more than 200 calories. And the food should be easy to digest and not something you'll be burping up 20 minutes into your run. Eww! Here are some ideas:

-- 1/2 cup plain low-fat yogurt, with 1 teaspoon honey and 2 tablespoons muesli.

-- 1 cup low-fat cottage cheese with 1/2 cup cubed cantaloupe and 2 tablespoons of low-fat granola. Swap out the cantaloupe for an equal portion of watermelon in the summer and diced apple in the winter.

-- 1 frozen waffle, toasted, topped with 1 tablespoon of natural almond or peanut butter and 1/2 pear, sliced.

(For a gluten-free option, use 2 brown rice cakes instead of the English muffin.)

[See What is Gluten, Anyway?]

In addition to drinking about eight 8-ounce glasses of water each day, you'll also want to take in 4 to 8 ounces of water for every 15 minutes of intense exercise. On days when you're doing a morning workout, you want to start hydrating as soon as you wake up. If you wait to drink until you're actually exercising, there won't be time to fully hydrate yourself. Even when it's cold outside, it's still crucial to drink water!

Maintaining your core body temperature is vital when you're exercising in cold weather, and it's tougher for your body to keep your core warm when you're not properly hydrated.

[See How to Have a Winning Winter Workout]

Do you need an electrolyte-enhanced sports drink? Only if you're exercising for more than an hour, or in hot, humid weather. Otherwise, your body will be able to replace any lost sodium and potassium through the food in your next meal. That brings us to the all-important recovery snack.

Post-Workout

Eating within two hours of a workout is important for muscle recovery. The faster you can take in carbohydrates after a workout--ideally within 15 to 20 minutes--the more quickly you'll be able to replenish muscle glycogen (stored energy), which is the fuel your body uses during exercise.

The components of a post-workout meal or snack vs. pre-workout food are similar: You want a mix of carbohydrates and protein, but since you'll have more time to digest the food, you can be a bit more adventurous and can go heavier on the protein. Also, intense exercise creates oxidative damage to your cells, so I like to include an antioxidant-rich food in my post-workout mix to help combat the added stress.

In terms of calories, if you're just grabbing a quick recovery snack before another meal, stick to 200 to 250 calories. But if you can actually sit down and take a bit of time to refuel, you may want to take in up to 400 calories.

If your goal is weight loss, make sure that your total calorie intake per day is still creating enough of a deficit to shed pounds. However, skipping recovery fuel by thinking that it will help you lose weight is counterproductive-- you won't be able to build muscle, and your next workout will suffer because you haven't replenished your stored fuel.

Here are some favorite post-workout options:

-- 1 whole-wheat English muffin, toasted, with 1/2 avocado, mashed, and a spritz of lemon juice: 250 calories.

-- 2 mini pitas and 2 eggs, scrambled, with 1 tablespoon grated Parmesan and 1 cup baby spinach: 330 calories.

-- 1 cheese stick or mini cheese round, 1 orange, and 1 energy bar or fruit and nut bar (180-200) calories: 380-400 calories.

Don't forget to keep drinking water after your workout and throughout the rest of the day. If you're training for a race, always make sure to test out a new fuel (bars, gels, etc.) before race day to make sure they'll agree with your stomach.

Keep moving, stay fueled and good luck with all of your 2013 goals!

[See 7 Mind-Blowing Benefits of Exercise]

Hungry for more? Write to eatandrun@usnews.com with your questions, concerns, and feedback.

Frances Largeman-Roth, RD, is a best-selling author and nationally recognized health expert, and the former Food and Nutrition Director at Health magazine for nearly eight years. Prior to that, she was part of the editorial team at the Discovery Health Channel and was managing editor at FoodFit.com. Frances is the author of Feed the Belly: The Pregnant Mom's Healthy Eating Guide and co-author of the best-selling The CarbLovers Diet and The CarbLovers Diet Cookbook. Frances earned her undergraduate degree from Cornell University and completed her dietetic internship at Columbia University in New York.