Can’t imagine a world without carbs? Whether it’s the Ketogenic, Dukan or LCHF diet, sometimes it seems like everyone is jumping on the low-carb bandwagon. But if you’re dedicated to seeing gains at the gym, upping your running mileage or HIITing it hard, cutting carbs might be the last thing you want to do. “Nothing makes me want to bang my head into the wall more than when I hear people promoting low-carb diets for performance,” says strength coach Tony Gentilcore, C.S.C.S., co-founder of Cressey Sports Performance. “Carbs are what fuels that performance, and what allows you to really burn calories and build muscle.”
RELATED: 3 HIIT Workouts to Take to the Beach
That’s because carbohydrates — whether they’re floating around in your blood as glucose or stored in your muscles and liver as glycogen — are your body’s favorite fuel for high-intensity exercise, says Susan Kleiner, Ph.D., R.D., author of Power Eating and a sports nutrition consultant to top NFL, NBA, and Olympic athletes.
Here’s why carbs are your friend, not your enemy.
Why Low-Carb Diets Hurt Performance
Ready to crush some treadmill sprints? Well, willpower alone won’t get you there. The secret sauce that will take your workouts to the next level is, you guessed it, carbs. When you train really hard, above 70 percent of your VO2 max (a measure of the peak amount of oxygen your body can take in and use in a minute), about 80 percent of your energy comes from glucose and glycogen, Kleiner says. This doesn’t just apply to marathoners, either. A recent study published in Sports Medicine showed that carbs boost not only marathon performance, but high-intensity interval training as well.
When your brain is deprived of bagels and other good stuff, it flips into self-protective mode and restricts the amount of carbohydrates your muscles can use. After all, your brain wants to make sure it gets all of the carbs it needs, too. About 90 percent of its energy comes from carbs. The result: Your workouts plummet. Plus, since you’re so low on energy, they still feel grueling. “Without carbs, you perceive that you’re training at a high level, but your actual energy level output is low,” Kleiner says. Your performance and results go nowhere fast.
And quite frankly, low-carb diets can make athletes feel like crap. “The low-carb diet craze has been a boon to my practice,” Kleiner says. “People come into my office in droves trying to figure out what’s wrong with them. They say their performance is going down. They say they are training harder but getting softer.”
How to Fuel Your Workouts with Carbs
Not everybody needs to carbo-load like they’re Meb Keflezighi. The amount of carbohydrates you need depends on how hard you’re exercising. If you’re going for a light jog, you don’t need a ton of carbs. But if you’re running long distances, performing weight lifting workouts or even doing a 20-minute HIIT session, you’re going to need some carbs in the tank, Kleiner says.
Your formula for success: Most active people should eat about two grams of carbs per pound of body weight every day, whether they’re vying for improved performance or weight-loss, she says. After all, to burn the most calories and fat during your workout, you need to run faster, lift heavier, and jump higher than you did before.
That being said, not all carbs are created equal. Throughout the day, aim to consume carbs with a low glycemic index (GI); they’ll provide sustained energy rather than spiking your blood sugar. Choose whole food sources of carbohydrates, like fruits, non-starchy vegetables, and whole grains, Gentilcore says. Your picks should be rich in fiber, and it’s always smart to pair them with lean protein and healthy fats.
90 Minutes Before Your Workout
About 90 minutes before a tough workout, it’s time to fuel up. At minimum, you need to eat one gram of carbs per kilogram of your body weight per hour of planned exercise, Kleiner says. So, if you weigh 68 kg (that’s 150 pounds), multiply that by how much time you’re spending working out that day. Hitting the gym for an hour and a half? You’d need a total of 102 grams of carbs.
If You’ve Only Got a Half-Hour…
When you’re looking for a quick fix of fuel, forget about whole grains. Reach for white bread, pretzels, white potatoes without the skins or bagels — you know, the refined carbs you typically try to avoid, Gentilcore says. “The more refined, the faster it will empty from stomach,” Kleiner says. Opt for carbs that are high GI, meaning they will significantly raise your blood sugar, and also quickly empty from your stomach into your bloodstream. After all, you can’t use that potato for energy until you’ve digested it — and running with a full stomach just sucks, she says.
Now is also the time to bust out your sports nutrition drinks, blocks and gels. They can spike your blood sugar quickly, and without putting a lot of stuff in your stomach. Take them about 30 minutes before hitting the gym and periodically throughout hour-plus endurance workouts. And, in case you were wondering, when you spike your blood sugar heading into exercise, your body doesn’t store the sugar as fat. It gets used as pure, calorie-burning, muscle-building energy, Kleiner says. Score.
What to Eat After a Workout (Hint: More Carbs)
You dominated your workout and you’re feeling like a sweaty beast (in the best way possible). Now what? Well, you need even more carbs — paired with protein, of course, Gentilcore says. Apart from helping your body restock its glycogen stores so you aren’t energy-drained for the rest of the day, carbs can help you build muscle. According to research in the Journal of the International Society of Sports Nutrition, insulin, which your body releases when you eat carbs, helps protein build muscle more effectively.
Embrace your inner kid and grab low-fat chocolate milk, Gentilcore recommends. Like commercial recovery beverages, it boasts a 4:1 carbohydrate-to-protein ratio, which is ideal for muscle recovery. In fact, research from Central Washington University shows that drinking it immediately after exercising and again two hours later is optimum for muscle synthesis. Likewise, Gentilcore advises scheduling your next meal — armed with non-starchy, fiber-rich carbs — to fall within an hour or two after you finish up a workout. Dig in, you deserve it.