Why carbs are important (especially for athletes)

While some people may have deemed carbohydrates nutrition public enemy #1, they actually play an essential role in fueling our body’s basic functions and everyday activities. Here’s what you need to know about this macronutrient, including why carbs are important and how they can boost performance.

Whether you're an elite cyclist chasing after a new PR or a marathon runner trying to go the extra mile, carbohydrates are an important–yet often overlooked–source of energy. Despite being shunned by popular diets, carbohydrates play a vital role in fueling our bodies and enabling us to perform at high levels. From providing quick-burning energy for exercise to fueling key organs, carbohydrates are an essential macronutrient for athletes and non-athletes alike. 

In this article, we will delve deeper into why carbs are important for athletes and share practical tips for incorporating them effectively into your diet to support your health and fitness goals. 

First, let’s look at what carbohydrates are, the different types, and their key functions in the body. 

Carbohydrate food sources

What are carbohydrates?

Carbohydrates are one of the three main macronutrients (alongside protein and fat) that provide energy to the body. They’re found in a wide array of foods —from bread and beans to potatoes, pasta, fruit, soft drinks, sweets, and more. 

Carbohydrate-rich foods are an important part of a healthy diet, especially for athletes and active individuals. Carbohydrates provide the body with glucose, which is converted to energy to fuel everything from your basic bodily functions to intense physical activity. 

How the body uses carbohydrates for energy

During digestion, sugars and starches are broken down into glucose, a simple sugar. Glucose is then absorbed in the small intestine, where it enters the bloodstream and is transported to cells for energy use. 

Most of the cells in your body use glucose for energy (along with amino acids from protein and lipids from fat), but glucose is the primary and preferred source of fuel for both your brain and working muscles.

Extra glucose not needed for immediate energy is stored in the liver and muscles as glycogen. Glycogen is a reserve carbohydrate source used primarily to maintain blood sugar and energy levels during short fasting stretches (like while you sleep) and periods of increased energy demand (such as when you exercise).

Once glycogen stores are full, the body converts excess glucose into fat for long-term energy storage. While fat is a rich energy source, converting fat back to glucose is incredibly inefficient; therefore, glycogen is the body’s primary and preferred source of backup glucose. 

Glucose is a vital energy source for your organs, muscles, and nervous system. It is the primary energy source for your brain, using about 120 g/day, roughly 60-70% of your total glucose metabolism [


]. Using your muscles, as with exercise, also increases glucose utilization 30-50 times greater than at rest [



Simple vs complex carbohydrates

A food’s composition of sugars, starches, and fiber (three types of carbohydrates) affects how quickly it is digested and determines whether it is a complex or simple carbohydrate. Let’s briefly break down the difference between simple and complex carbohydrates. 

Simple carbs

Simple carbs are quickly and easily digested by the body, which makes them a good source of quick energy during a strenuous workout [



Studies show that athletes may benefit from simple carbohydrates before, during, or just after exercise as these are easily digested and quickly absorbed [


]. With simple carbs, you’re less likely to experience exercise-related GI upset, and the muscles you just worked can efficiently get the energy they need. 

Good sources of simple carbohydrates to fuel up for a long run, ride, or swim include honey, fruit juice, sports drinks, gels, energy bars, and white (refined) grains like bread, rice, and pasta. 

While they can be a good source of quick energy during a strenuous workout, consuming too many simple carbohydrates (like soda, sweets, candy, and white bread) can cause spikes in blood sugar, weight gain, and increase your risk for diabetes, heart disease, and high cholesterol. As such, it’s recommended to limit your intake of these foods and consume no more than 10% of your daily calories from added or refined sugars [



Complex carbs

Complex carbohydrates provide essential vitamins and minerals, promote regularity and a healthy digestive tract, and can be an excellent source of energy. This is because these carbohydrates are mostly comprised of starches and fiber. 

Starches consist of longer chains of sugar molecules than simple carbohydrates, which take longer to break down, making them less likely to cause spikes in blood sugar and provide longer-lasting energy than simple carbs. 

Fiber is an indigestible carbohydrate that passes through the intestines, stimulating and aiding digestion. Because the body cannot break it down, fiber is beneficial for regulating blood sugar, lowering cholesterol, and helping you feel full longer [



Some of the best food sources of complex carbohydrates include [



  • Whole grains, such as brown rice, quinoa, rolled oats, and 100% whole grain bread or pasta

  • Fruits containing fiber, such as bananas, apples, and berries

  • Starchy vegetables, including sweet potatoes, carrots, peas, and corn

  • Legumes, such as beans and lentils

Carbohydrates for exercise

Although protein and dietary fat can provide the necessary energy to perform physical activity, carbohydrates are king when it comes to fueling fitness endeavors. This is because working muscles can utilize carbs both fast and efficiently. In fact, carbs are the only macronutrient that can be broken down rapidly enough to provide energy during higher-intensity (anaerobic) exercise [



Given this, the availability of carbohydrates in the body can profoundly affect your energy levels, endurance, performance, and even recovery. Not having enough carbs on board can have detrimental effects on your body composition, physical performance, and recovery — whereas increased carbohydrate intake before, during, and after exercise can have performance and recovery benefits [



Adequate carbohydrate intake also plays a crucial role in maintaining lean mass and optimizing the use of dietary protein in the body. When carbohydrates are the body’s primary fuel source, particularly during high-intensity physical activities like competitive running, cycling, and strength training, protein is spared from being used as an alternative energy source. By ensuring an adequate supply of carbohydrates, more protein is available for tissue repair and muscle building which can have profound effects on strength, endurance, and recovery [



Here’s more on the benefits of carbs for active individuals when consumed before, during, and after exercise. 

Pre-exercise carb benefits

Carbohydrate intake before strength and intense endurance exercise is crucial for athletes, as it helps to top off glycogen stores. Adequate glycogen stores are essential for maintaining energy levels during exercise and preventing early fatigue [



Whether you’re a competitive cyclist, runner, swimmer, or triathlete, research shows increasing carbohydrate intake days and even 3-4 hours before exercise can increase muscle glycogen and enhance performance in endurance events, particularly those lasting 90 minutes or more [



Benefits of carbs during exercise

Consuming carbohydrates during exercise can help maintain stable blood glucose levels and prevent the depletion of muscle glycogen stores, allowing athletes to perform at their best for longer periods [



Post-exercise carb benefits

​​Carbohydrates are essential for athletes after exercise, as they aid in recovery by replenishing muscle glycogen stores and supporting muscle protein synthesis. Consuming carbs after a workout also helps to restore liver glycogen stores, which is crucial for maintaining energy levels during future exercise sessions.

Research shows adequate carbohydrate consumption after exercise promotes rapid repletion of liver and muscle glycogen stores to enhance recovery and minimize performance decline in the following days [



Pairing your post-workout carbs with protein (ideally in a 3:1 carb-to-protein ratio) may further enhance your recovery by boosting muscle repair and growth through increased protein synthesis [



toan drinking protein

How Elo Smart Protein can help boost recovery 

Elo Smart Protein

is the world’s most personalized protein recovery product. Each batch is custom-blended to meet your unique needs and deliver the right amount of nutrients after each workout to help you recover faster. 

Your unique Smart Protein blend is determined using a combination of data from wearables and activity apps, as well as your dietary preferences and goals. Your information is then matched with the latest scientific research to determine a blend of ingredients that both maximize post-workout recovery and support your health goals. Elo’s functional boosts (like carbohydrates, supergreens, turmeric, and probiotics) can help offset nutritional gaps in your diet, enhance your recovery, and help you meet your health goals. 

At Elo, we offer two types of carbohydrates for boosts: branched cyclic dextrin and oat starch. Both types can be useful for athletes looking to replenish energy stores during and after exercise [


]. The amount of each you receive in your blend will be determined based on your energy levels, activity data, and questionnaire answers. 

Check out this article to learn more about Smart Protein and what boosts may be included in your formula.


Think of it as a supplement and protein powder in one scoop, uniquely designed for you and your recovery needs. Smart Protein is perfect for exercise enthusiasts of any age.

Try Smart Protein today and get 30% off your first month with code TRY30

How many carbs do you need in a day? 

According to the Dietary Guidelines for Americans, carbohydrates should make up approximately 45-65% of your daily caloric intake (primarily in the form of whole grains, fruits, vegetables, and legumes), and less than 10% of these calories can come from added sugars [



To determine where you fall in this range, consider your usual activity level:

  • For recreational exercisers focused on general fitness, 45-55% of calories from carbohydrates (3–8 g/kg/day) is generally adequate [



  • Endurance athletes training two or more hours/day will likely need to consume >60% calories from carbohydrates (5–8 g/kg/day) [



Carbohydrate recommendations before, during, and after exercise

Aside from ensuring you’re getting enough of the right carbohydrates, timing your carb intake around a run, ride, or strength training session can positively impact your endurance, performance, and recovery [




]. Here are some recommendations to help you optimize your carbohydrate intake before, during, and after exercise.

Before exercise

If you plan to exercise for one hour or longer, aim to consume 1-4 g of carbs/kg of body weight 1-4 hours before exercise [


]. Doing this will top off your glycogen stores and ensure glucose is available for immediate use. 

Light, rapidly absorbed carbs like a banana or white toast with jam are good options for topping-up carbohydrates before a training session or event. Skip high-fiber and high-fat options, as these can lead to gastrointestinal distress. 

During exercise 

How many carbs you need during exercise will depend on the duration and intensity of the activity. 

  • For moderate- to high-intensity exercise lasting up to one hour, small amounts of carbohydrates, including mouth-rinsing with sugar water, may positively affect performance [



  • For 1-2 ½ hours of exercise, athletes will benefit from consuming 30-60 g of carbohydrates/hour [



  • For endurance events lasting >2 ½ hours, athletes may benefit from higher intakes of up to 60-90 g/hr [



Again, rapidly absorbed sources of carbohydrates like sports drinks, gels, sports drinks, and bananas are preferable to minimize gastrointestinal distress mid-exercise. 

After exercise

Your post-workout carbohydrate needs will largely depend on how much you weigh and how hard you’re training. 

  • After a moderate- to high-intensity workout lasting >45 minutes, you’ll want to consume 45-90 g of carbohydrates within one hour of finishing. 

  • For longer workouts or high-volume training (2-3 hours/day, 5-6 days/week), athletes should aim to consume 1.0-1.2 g/kg per hour for the first 4-6 hours of recovery [





Remember, the more active you are, the more carbs (and protein) you need to support the physical demands of training and recovery. Protein supplements created with optimal carbohydrate ratios, like

Elo Smart Protein

, can be a convenient and cost-efficient way to deliver the perfect amount of post-workout carbs and protein to support your recovery. 

Here are more ways to optimize your

post-workout nutrition


Tips for optimizing your carb intake

Regardless of whether you’re an everyday exerciser or a competitive athlete, optimizing your carbohydrate intake will support your overall health and help you maintain energy levels. Here are some tips for optimizing your carb consumption to support your health and fitness goals.  

  • Quality matters. Focus on nutrient-dense, high-quality carbohydrate sources as part of a balanced diet.

  • Plan ahead. Plan your carbohydrate intake around your exercise sessions to ensure you’re well-fueled and maximizing

    post-workout recovery


  • Pay attention to your energy levels (both during and after exercise). If you’re bonking or taking several days to recover, increasing your carb intake may help. 

  • Consider using carbohydrate supplements. Gels and energy drinks during exercise and

    Elo Smart Protein

    after exercise can help you maximize your performance and recovery.


Carbohydrates are an indispensable component of our diets, essential for athletes and non-athletes alike. They are crucial in fueling everything from your body’s most basic functions to your greatest athletic achievements. By including the right types and amounts of carbohydrates in your diet, you can maintain stable energy levels and promote overall well-being while fueling your fitness goals. At


, our expert dietitians can help you optimize your carbohydrate intake to maximize your energy levels and performance gains. 

Disclaimer: The text, images, videos, and other media on this page are provided for informational purposes only and are not intended to treat, diagnose, or replace personalized medical care.

Key takeaways

  • Carbohydrates are the preferred energy source for the brain and exercising muscles.

  • Complex carbohydrates take longer to break down, making them less likely to cause spikes in blood sugar and provide longer-lasting energy than simple carbs.

  • Good sources of complex carbohydrates include whole grains, fruit, starchy vegetables, and legumes. 

  • Timing your carb intake around exercise can positively impact your endurance, performance, and recovery. Pairing your post-workout carbs with protein (ideally in a 3:1 carb-to-protein ratio) may enhance recovery by boosting muscle protein synthesis.

  • With products like

    Smart Protein

    , you can optimize your carbohydrate intake to increase energy levels and enhance performance and post-workout recovery.


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