Carbs are found in all foods except meat, including grains, fruits, vegetables and even dairy. Regardless of the source, after absorption, carbs exist in the body as glucose. Glucose is the body’s first and often preferred energy source. When you consume more carbs, or energy, than your body needs, the excess glucose is stored in your liver and muscles as glycogen. To burn carbs you must use available glucose, and then deplete glycogen stores.
If you’ve ever eaten a low-carb breakfast, you know that it does not increase brain power. Your brain uses carbohydrates as its primary source of energy, so you might feel lethargic after a low-carb meal in the morning. But don’t grab that extra-large chocolate muffin just yet; make your carbs count by choosing fruits and whole grains. A quick surge of energy from a sugary pastry can leave you feeling just as depleted and sluggish as no breakfast at all.
Carbohydrates provide the major energy source for your muscles. Your body converts this macronutrient — found in starchy vegetables, sugar, fruits and grains — into glucose, which it then transports to cells for energy or stores for later use. Once your glycogen stores are full of this glucose — after about 300 to 400 grams — the body stores the excess as fat. Prolonged cardio activity performed at an intense level is best for working through your carbohydrate stores. Once you’ve stored carbs as fat, they don’t burn carbs as efficiently.
Here are ways to burn carbs and maximize your carbohydrate intake to reach your goals:
Fastest Way to Burn Carbs
Maintain a high-carbohydrate diet. Make carbohydrates consist of 60 to 70 percent of your daily calorie intake to get your body accustomed to burning carbohydrates primarily for fuel. Adequate carbohydrate intake also ensures your body has carbs, or energy, to burn.
Work out at a high intensity for an extended period of time, such as running a half-marathon or biking for several hours. High-intensity means a level you can maintain for the duration of the event but that still feels challenging. The American Council on Exercise describes it as about 80 to 95 percent of your maximum heart rate. Train over time to be able to hold this intensity for 90 minutes or longer.
Perform a quick all-out set of pushups for a minute, a 400-meter running sprint, 50-meter swimming sprint or a set of eight to 12 repetitions of a strength exercise using a weight that is hard to complete. These types of intense movement that you can only maintain for a minute or so are examples of use of the glycolytic energy system, which uses carbohydrates almost exclusively for energy. You’ll burn carbs quickly with such activity, but because they’re so intense, you can’t maintain them for long periods of time and won’t burn a large net amount of carbohydrates.
You can train your body to use different energy systems for endurance activity. Your body reaches for carbohydrates first during submaximal endurance exercise, the point at which you work at 80 to 95 percent of your heart rate, but if you’ve trained your body to burn fat during exercise by performing fasted workouts and consume a diet rich in protein and fat, you’ll use more fat for fuel.
Intervals of glycolytic exercise may burn carbs during the high-intensity portions of the workout, but actually boost your fat-burning capacity post-workout.
Skip the Pre-workout Meal
When you exercise, your body uses available glucose to provide energy. If you have just eaten a meal or had a pre-workout drink, this is first used to fuel your body. If you want to burn carbs already stored in your body, do not take in excess carbs before or during your workout. Avoiding carbs pre-exercise may reduce the level you are able to perform at and may cause you to become tired sooner, but if you keep providing fuel for your body, your body will never use the fuel it has stored.
Once available glucose is used, your body will convert stored glucose, called glycogen, back into its useable form. How soon this occurs depends on your exercise intensity. High intensity exercise, such as intervals, burn stored carbs sooner. To perform intervals warm-up on your preferred cardio machine, or by jogging outdoors. Then sprint, or pedal, or row, as fast as you can for 30 seconds. Follow this with two minutes of active rest at warm-up speed. Repeat this cycle eight times for a short, carb-burning workout. Other options for intense cardio include group fitness classes like Zumba or cycling classes focusing on sprints or hills.
This exercise modality is a fast and effective way to burn through carbs and scorch calories. It’s also quick, effective and gets in both cardio and strength training, both key components of a well-rounded fitness program. Strength training (AKA resistance training or weight training) in general raises your resting metabolic rate (RMR), meaning you’ll burn through more carbs and calories while at rest, all day long.
Circuit training takes this one step further by pairing strength training exercises in a circuit with high intensity cardio bursts, meaning you’ll be doing anaerobic exercise that uses up glucose and depletes glycogen stores. Choose exercises that target different muscle groups or are total body movements like squats, lunges, pull-ups, push-ups and deadlifts. In between, insert a 30-60 second cardio interval, which can be anything from jumping jacks, lateral hops, speed skaters, burpees or squat jumps, among others.
Interval training is another way to ensure your cardio is tapping into those glycogen stores, meaning it burns through stored carbs. Exercise intensity is what dictates whether these stores are tapped into, and interval training is another excellent higher-intensity modality.
The beauty with intervals is they are completely adaptable to your fitness level and abilities. Intervals means switching between periods of higher intensity and lower intensity. Even better, studies show that HIIT (high intensity interval training) particularly helps to burn visceral fat around the mid-section (love handles included) that is linked to many chronic diseases.
I’ve used and recommended this interval workout timer for at-home sessions, and have found it to be very worth the small investment.
Do Low-Impact Cardio
Low impact cardio like walking, light biking, swimming and dancing won’t necessarily use glucose as readily as high intensity exercise, but it is an important piece of the metabolic health puzzle. The fact of the matter is, if you are not metabolically healthy and balanced to begin with, your body won’t be able to effectively burn carbs or any other fuel source efficiently.
What’s more, low impact cardio improves circulation, lowers insulin levels, strengthens bones and muscles, supports cognitive function, boosts cardiovascular health and even improves your mood. According to one study, the more steps people took during the day, the better their moods were and the more energetic they felt. This is because walking releases natural endorphins throughout the body that leave you feeling happier and more at-ease. The more energetic you are, the more active you are and the more carbs you burn.
Avoid Processed Carbs
Processed carbs include packaged and refined carbohydrates that no longer resemble foods from nature. Refined carbs and grains are those that have had their nutritious components and fiber removed in processing. White flour (refined wheat) is the most common type, and is the main ingredient in commonly consumed refined grains, such as pasta, bread and baked goods. While whole wheat pasta is slightly better than white pasta, it still has a much higher glycemic index than whole foods-based complex carbohydrates, which means it more rapidly spikes your blood sugar.
A high-refined carbohydrate diet is also a leading cause of high triglyceride levels, which increases your chances of developing heart disease. Carbohydrates that are best metabolized (burned) by the body are those that come from whole foods sources.
Enjoy Starchy Vegetables and Fruits
In an ideal world, the bulk of your carbs will come from starchy veggies and fruits. Starchy vegetables include delicious foods like sweet potatoes, yucca, plantains, parsnips, turnips and winter squashes, for example. The body recognizes these carbohydrates as actual foods and their absorption and digestion is slowed by their naturally occurring fiber and nutrients. That means that they will have less of an impact on blood sugar, will provide more long-lasting energy and are much less likely to lead to weight gain or other metabolic issues.
For a primer on whole foods eating for optimal health, I love this book by Dr. Mark Hyman.
Stick to Whole Grains
Instead of white rice that contains very little nutritional value (unless it has been cooked and cooked, in which case interesting research shows its value as a resistant starch), go for whole grain options instead for more fiber and nutrients. This means brown and black rice, quinoa, barley, millet, buckwheat, corn and whole oats. Skip more refined grains like white rice, instant oats, processed cereals, breads, pastas, grits, tortillas and others.
Time Carbs After Exercise
Being that your glycogen stores are depleted during intense exercise, timing a higher carbohydrate meal within the 2-3 hour window post-exercise can mean you burn carbs more efficiently and refill your glycogen stores. This is especially true for endurance sports like long distance running, swimming, biking or other activities.
After exercise your body experience a phenomenon called excessive post-exercise oxygen consumption, or EPOC. This refers to the 2-3 hour period after high intensity cardio where your metabolism is increased and you burn calories at a faster rate. Ideally you will eat a balanced meal within 30-60 minutes post-workout to support optimal recovery, decrease muscle soreness and take advantage of your metabolic advantage to burn carbs.
Know How to Read Labels
Learning how to be a nutrition label detective is surprisingly key when considering how to best burn carbs. Many refined grains and sugars are hiding in processed and packaged foods, and marketing claims can be quite deceiving. Many products claim to be low calorie, low carb, low fat, heart-healthy, natural, etc, but you’ll only decipher what truly lies within that packaging from knowing how to read the ingredient list and nutrition facts. Check out this helpful guide from the Academy of Nutrition and Dietetics.
Keep Portions In Check
Keep in mind that even when eating the most nourishing of carbohydrates, too much of them is likely to lead to weight gain in most people. While I don’t necessarily recommend counting calories and measuring out portions, implement tricks like using a smaller plate, putting your fork down between each bite and chewing each bite very thoroughly. This gives your body and brain a chance to register your level of hunger and satiety, and is foundational for healthy digestion and a conscious connection with food.
Carbohydrates can absolutely be part of a well balanced diet, regardless of your goals. If you largely stick to the overall principle of eating real, whole foods most of the time with all macronutrient groups, you’re probably on the right track.