What to eat to get the most out of your workout

Hitting the gym right after downing some poutine is probably a bad idea. But not eating enough can affect your performance too.

So what should you eat to fuel up before a workout? It’s a little complicated.

Partly, it depends on your goals, said Dan Moore, an assistant professor of kinesiology at the University of Toronto. If you’re just going to the gym twice a week for light exercise, he’s not sure you need to pay much attention beyond simply eating regular, healthy meals.

“If your goal is to build muscle or if you’re training for a race, then you’re going to probably be exercising at least three up to five or six times a week. I think that’s where you start to focus in on, what am I eating, and when am I eating it?”

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And, if you’re looking to lose weight, you need to keep in mind that anything you eat before a workout has to fit into your overall diet plan, and is appropriate to how many calories your workout will burn, he said.

The intensity and duration of your workout matter too, said Hugues Plourde, a dietitian with McGill University.

Keeping your goals in mind, here’s what researchers suggest to power your workout.

Light intensity

For light-intensity workouts, experts agree you don’t need much. “If it’s a light intensity, this means you’re not sweating that much, you’re walking the dog – depends how quick your dog is – but for that, you don’t have too much restriction,” Plourde said.

“What you eat before is pretty much just there to help you accomplish the exercise, if you need food to do it,” Moore said. He thinks your ordinary meals should generally be fine during light exercise and you don’t need to worry about anything more.

Registered dietitian and personal trainer Nanci Guest agrees – she thinks water is enough, with maybe a light snack like half a cup of yogurt with some nuts and dried fruit if you feel you need something.

The exception to this, Plourde said, is if you’re doing low-intensity exercise for a very long time – like a four-hour walk or 20-kilometre cross-country ski – in which case you might want a snack sometime during the workout.

Moderate intensity

This is where you have to start paying attention, the experts say.

In a 2017 position statement, the International Society of Sports Nutrition recommends that exercising individuals make sure to meet their recommended intake of protein (the current Canadian recommendation is about 0.8 grams of protein per kilogram of body weight – more like 1.2 to 1.7 grams for endurance or strength athletes), preferably eaten in evenly spaced meals throughout the day.

A joint position statement from the Dietitians of Canada and some American dietetic and sports medicine bodies recommends that before exercise, a meal or snack should be relatively low in fat, high in carbohydrate, moderate in protein and contain enough fluid to keep you hydrated.

So what might that look like? Depends on how much time you have.

With hours before your workout, you can eat a medium-to-large meal that includes carbohydrates, protein and some fat, Guest said. Guest, who is days away from earning a PhD in nutrition, suggests something like a turkey sub sandwich with an apple and a cup of milk.

If you have less time to spare, the meal should get smaller since you won’t have time to digest much. If you’ve only got 30 minutes before your workout, she suggests going low-protein and high carbohydrate with no fat and fibre, so something like watered-down juice or a small portion of banana or dates.

High intensity

If Plourde is about to do a bike race, where he expects to be cycling so hard he can’t speak, he’s going to eat very light food.

“An hour before, forget about having a piece of cheese or an egg or anything like that,” he said. “I’m just going to throw up if I’m eating that an hour before because it’s going to be so intense, I’m going to be nearing my max.”

When you eat a big fatty meal and then exercise too hard too soon, your muscles want blood to work and your stomach wants blood to digest, and that can make you nauseous and even throw up, Plourde said. “I’m sorry, I need to eat light if I know that I am doing high-intensity intervals.”

“The rule of thumb is the higher intensity, the longer before the workout you should have eaten,” Guest said.

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When you’re training, said Moore, your body uses up a lot of carbohydrates, so you need to make sure it has some to burn.

Having a carb-based meal four hours before competition improved athlete performance, according to some studies, though there is disagreement on this point, according to the International Society of Sports Nutrition. It still recommends eating a lot of carbs on a competition day though.

For some extra fuel, you might want to eat something with a lot of carbs an hour or two before an intense workout, said Moore, such as a bagel or some bananas to top up your energy stores.

It’s also helpful to drink a carbohydrate solution, like a sports drink, during extended bouts of high-intensity exercise lasting more than 60 minutes, or during heavy resistance exercise, according to the Society’s position paper.

If you don’t like Gatorade or other such commercial sports drinks, Guest suggests making your own by diluting 30 per cent fruit juice in 70 per cent water.