The body needs fuel to perform. But what fuel? And when? These are the questions many of us ask ourselves as we get ready for a long run or finish up an hour in the weight room.
"You wouldn't expect your car to run on an empty tank, right? Same thing with your body. If you want to perform well, you have to fuel well," says fitness trainer Mansur Mendizabal. This means giving your body the carbohydrates and protein it needs.
Pre-workout: Early-morning workouts present challenges beyond just dragging yourself out of bed. If you have less than an hour before your workout, you will have to eat something that is easily digestible and high in carbohydrates. And, of course, make sure you hydrate.
"If you are working out early in the morning, maybe you have a banana before the workout, since the body has used up most of the glycogen stores overnight," Suzanne Girard Eberle, sports nutritionist and author of "Endurance Sports Nutrition," says. "A sports drink may even be appropriate."
But to some, eating a meal early in the morning just doesn't feel right.
For them, nutritionist Kristen Ciuba recommends splitting breakfast in two — eating half of it before working out and half after. Think peanut butter on half a slice of whole-wheat toast before working out and then the other half afterward.
"Time it so you are eating at least 30 to 40 minutes before the workout and then 30 to 40 minutes after the workout," she says.
But if you have more time, full meals — which balance carbohydrates, protein and fat — are the best preparation for any physical activity, Girard Eberle says. In other words, if you can swing it, eat a full meal two hours or more before working out, she says.
Post-workout: After a workout, the muscles are repairing, and it's important to help that process along by supplying the body not only with carbohydrates, but also with protein, Girard Eberle says.
"If you can time it so you are eating a well-balanced meal within 30 to 60 minutes after working out, that would be best," she says.
If not, go for a snack that has some carbs and some protein. And rehydrate, particularly in the heat.
For workouts lasting longer than 90 minutes, she recommends using sports drinks or GU, a sports nutrition gel high in carbohydrates that endurance athletes often use during long-distances rides and runs.
So what if your main goal is to lose weight and get stronger?
It's important to create a calorie deficit (consume fewer calories than you expend), but that doesn't have to be done within the same hour or two that you are working out, says nutritionist Kristen Ciuba.
"Try to spread your calories throughout the day," she says. "Be careful of the total (calorie intake), but don't cut out the snack before or after the workout."
So, if your daily intake is 1,500 calories, then you could have 400 calories per meal and two snacks of 100 to 150 each, she says. Most people eat most of their calories at night and few in the morning. But if you work out in the morning, fuel then, and cut your portion sizes in the evening.
"Your goal is you want to burn more calories by working out as hard as possible," Ciuba says, adding, "You have to make sure your body is ready."
Boston is a fitness trainer and freelance writer.