Many of us exercise so we'll lose weight. And to help us shrink a little faster, we also watch what we eat. So wouldn't snacking before working out completely defeat the purpose -- wouldn't it just add extra calories to our diet for us to burn off?
Not so, says Sarah Maughan, registered holistic nutritionist at Totum Life Science in Toronto. "Many people, especially if they're trying to lose weight, think they'll lose weight faster that way, but if you work out without any fuel, you're working out for no reason," she says. "Your muscles will fatigue early on and you'll be trudging through your workout so you won't activate the correct muscles and you'll be unable to finish your reps."
If you haven't eaten a thing in the last two hours or so -- and are thinking about hitting the gym tonight -- you definitely need a snack before you exercise, says Maughan. Consider when your last meal was and how hungry you are. Aim to have a snack 30 to 45 minutes before you workout.
You'll have to try out a few different "snacking" times to determine what works best for you and your body. "If you get nauseous when working out, push back your snack time to one hour before you exercise. If you tend to digest quickly, aim to have a full meal 90 minutes before you exercise rather than just a snack," she says.
As for what to eat before a workout, A few celery sticks with some hummus won't cut it. You need carbs to provide your body with immediate energy, says Maughan. Try fruit or a smoothie, for example, or some whole-grain bread.
If you're fitting in some fitness in the morning, oatmeal is a great choice. Numbers wise, your snack should ideally be 100 to 150 calories and provide 25 to 30 grams of carbohydrates. ("For example, a nice large apple," says Maughan.)
What you shouldn't do is use this as licence to eat refined carbs. Stick with nutrient-dense options such as the ones outlined above. High-glycemic choices -- such as a doughnut or a cookie -- will only spike your blood sugar and will cause you to lose energy.
Consider the type of exercise you're doing as well. If you're a cardio junkie, you may find fruit will fuel you. "People doing cardio often want to eat lighter -- on a fuller stomach you may not be able to breathe as well when you're bouncing around," says Maughan. When your workout consists of weight training, on the other hand, you can have something more substantial, such as yogurt, nuts or a smoothie with protein powder.
If you're training for an endurance sport -- such as running or cycling a long distance -- you'll want to consume carbs for several days before your event to build up your glycogen stores. Also, plan for a meal high in carbs and healthy fats the night before your event.
Some preliminary data, published recently in the journal Medicine & Science in Sports & Exercise, also shows a high-protein diet can boost endurance levels slightly (they may also reduce stress) in high-powered athletes.