Here’s some brief insight into what, why, and when to eat. How you do it is your call.
Like most things, this will depend on your goals. If you have performance-related goals, eating before and after exercise is critical. If you’re just recreationally active, you probably don’t need to be all that concerned about this stuff, as long as you’re feeling good.
Before exercise: eating before exercise will improve performance, and will prevent the loss of protein that you’ll need for recovery. For those of you that are trying to break records, each athlete will have different needs. Whatever you choose to eat should prepare you for the upcoming activity; you should eat enough to prevent feeling hungry, but not anything that will be sticking with you undigested, like bacon-wrapped chicken fried steak fritters.
Drink enough fluids to stay hydrated and facilitate digestion, and limit fats and fiber so your stomach can empty. Carbohydrates are important: they maintain your blood glucose and muscle glycogen levels, or the energy you use during exercise. It doesn’t matter what type of carbohydrate you choose; there are no clear winners in the research. A little protein is good here too; you’ll need it later on in recovery. And, most importantly, eat foods that are familiar to you. Don’t try that exotic new curried sunflower ratatouille yet.
The timing and size of your meal are directly related: more food requires more time to digest. And each athlete will fall somewhere different on that continuum of quantity and timing. Here it’s important to know your specific needs: experiment! While some athletes like a big huge meal before competition or training, for others this may be recipe for intestinal disaster.
If you can’t move without a little food in your belly, eat a smaller meal closer to activity. A pb&j or a small bowl of oatmeal an hour before are good examples. But if you’re an endurance competitor and you can stomach it, eat a huge meal several hours prior to your race or hard training session, loaded with carbs and calories. For endurance performance, more carbs will improve performance. How much? About ten to fifteen pancakes can give you a boost if you have enough time to digest all that food.
During exercise: the main goals during longer endurance events are to replace fluid losses and maintain blood sugar levels in the form of carbohydrates. Consuming carbs during endurance events is especially important if you haven’t loaded up on carbs in the days and hours prior, or if you’ve been restricting calories for weight loss purposes.
The specific recommendation is about 1/2 gram of carbohydrate per pound of body weight per hour. In other words, sipping on a gatorade, munching on a snack bar, or slurping some gel every 15-20 minutes. If you go down the food or gel route, make sure you stay hydrated to digest and absorb it. The type of carbohydrate doesn’t really matter much, but most research indicates fructose may not be a good choice. So don’t drink a Dr. Pepper or eat a handful of grapes during your race. However, kids should still eat orange slices during halftime of their soccer games, just because.
After exercise: The timing and type of meal or snack you consume after exercise depend on what you just did, and for how long. If you jogged for 20 minutes, you didn’t really deplete enough energy to replace, and you didn’t damage any tissues that may need repairing. But any type of exercise that’s longer in duration and/or more strenuous will require some fuel to repair and recover.
A post-training or -competition meal is important for you to be able to exercise again in the future. If you’re planning on exercising again today or tomorrow, it’s critical. But if you just did your last competition of the season and you’re about to take a few weeks off, it’s probably okay to go straight to the celebratory beers.
However, if you just burned a whole bunch of calories in an exercise bout and you’re planning on doing a similar workout the next day, you should consume carbs within thirty minutes of completing exercising. The specific recommendation is about 1/2 gram per two hours per pound of body weight, or about 200 grams (the amount in that huge pancake stack) over the next several hours for a 180-pound individual.
If you did some high intensity exercise or resistance training, you need to consume protein within one hour of finishing exercising to repair your body and get the structural strength-related adaptations that are possible. How much protein do you need? The quantity within that hour window isn’t as important as how much you’re eating throughout the day. That should be 1/2 to 1 gram of protein per pound of body weight per day, with heavy resistance training requiring more.