Should you eat more carbs to build muscle? The definitive guide

October 18, 2025 •

4 min read

During intense exercise, your muscles primarily use carbohydrates stored as glycogen for energy. So, should you eat more carbs to build muscle and maximize your performance in the gym? This article explains the vital role carbohydrates play alongside protein for effective hypertrophy and recovery.

Quick Summary

Carbohydrates are a crucial fuel source for high-intensity training, replenishing muscle glycogen stores and sparing protein for muscle repair rather than energy. Strategic carb intake, combined with adequate protein, optimizes workout performance, enhances recovery, and supports lean muscle growth effectively.

Key Points

Carbs Power Workouts: Carbohydrates are the body's primary fuel for high-intensity resistance training, enabling you to lift heavier and push harder.
Replenish Glycogen: Intense exercise depletes muscle glycogen stores, and consuming carbs is essential for replenishing them to aid recovery and prepare for the next session.
Prevent Muscle Breakdown: A sufficient intake of carbohydrates creates a 'protein-sparing effect,' ensuring that dietary protein is used for muscle repair and growth instead of being converted for energy.
Strategic Timing is Key: For maximum benefit, consume complex carbs a few hours pre-workout and simple, fast-digesting carbs immediately post-workout to enhance glycogen resynthesis.
Avoid Very Low-Carb Diets: Extremely low carbohydrate intake can impair exercise performance, hinder recovery, and potentially increase muscle breakdown, making it suboptimal for maximizing muscle gains.
Choose the Right Carbs: Opt for nutrient-dense complex carbohydrates like oats, quinoa, and sweet potatoes for sustained energy throughout the day, using simple carbs strategically around workouts.

The Fuel for Your Muscle Engine

For decades, carbohydrates have been a misunderstood macronutrient, often demonized in weight-loss and fitness circles. However, for anyone serious about building muscle, carbs are an indispensable part of their dietary strategy. While protein supplies the building blocks for muscle repair and growth, carbohydrates provide the high-octane fuel required to power intense workouts and facilitate recovery. Understanding this synergy is the key to unlocking your full potential for muscular hypertrophy.

The Glycogen Connection

Your body stores carbohydrates in the muscles and liver in the form of glycogen, which acts as the primary energy source during moderate to high-intensity exercise, such as weightlifting. The duration and intensity of a workout directly impact how much glycogen is used. High-volume and high-intensity resistance training sessions can significantly deplete muscle glycogen stores, leading to premature fatigue and a decline in performance. By consuming sufficient carbohydrates, you ensure your glycogen tank is full, allowing you to train harder, lift heavier, and maintain intensity throughout your session. The more you train, the more efficiently your body learns to store glycogen, further increasing your capacity for intense work.

The Protein-Sparing Effect

One of the most critical roles of carbohydrates in muscle building is the "protein-sparing effect". When you consume enough carbohydrates, your body prioritizes them as its main energy source. If carbohydrate intake is insufficient, your body may be forced to break down muscle tissue for amino acids to convert into glucose for energy—a process called gluconeogenesis. By providing ample carbohydrates, you protect your hard-earned muscle mass, ensuring that the protein you consume is used for its primary purpose: repairing and building new muscle fibers. This is particularly important when operating in a calorie deficit, where the risk of muscle catabolism is higher.

Hormonal Support

Carbohydrate consumption also triggers the release of insulin, a powerful anabolic (muscle-building) hormone. Insulin plays a crucial role in shuttling glucose, as well as amino acids from protein, into muscle cells. This creates an optimal anabolic environment for muscle repair and growth. Furthermore, maintaining a balanced carbohydrate intake helps regulate other hormones, such as cortisol, a stress hormone that, when chronically elevated, can lead to muscle breakdown. Low-carb diets can sometimes lead to increased cortisol levels, which is detrimental to muscle-building goals.

Timing Is Everything: When to Eat Carbs

For active individuals, the timing of carbohydrate intake can be a key factor in maximizing performance and recovery. Focusing your carb intake around your workouts can provide the most benefit, though meeting your overall daily carb needs is still most important for the average person.

Pre-Workout: Consuming carbohydrates 1–4 hours before a workout helps top off glycogen stores and provides sustained energy. Complex carbs are best for meals consumed 2-3 hours out, while simpler carbs are good for a quick energy boost closer to the session.
Intra-Workout: For very long or intense sessions (over 60-90 minutes), consuming simple carbs during the workout can help maintain energy levels and delay fatigue. Options include sports drinks, energy gels, or bananas.
Post-Workout: This is a crucial time for replenishment. Consuming high-glycemic carbohydrates within 30 minutes to 2 hours post-workout can dramatically accelerate the rate of muscle glycogen resynthesis. Pairing these carbs with protein further enhances muscle protein synthesis and recovery. A ratio of roughly 2-4 grams of carbs for every 1 gram of protein is often recommended.

Finding the Right Balance: High-Carb vs. Low-Carb

Research has explored different macronutrient strategies for muscle building. While some low-carb approaches can be effective for fat loss, studies have repeatedly shown high-carb diets to be superior for maximizing performance and muscle mass gains during resistance training. A 15-week randomized controlled trial found that resistance-trained men on a high-carbohydrate/low-fat diet experienced greater increases in strength and lean body mass compared to those on a low-carbohydrate/high-fat diet. The potential negative impact of very low carb intake, such as higher cortisol levels and impaired performance, makes it a less than ideal strategy for many seeking optimal muscle gain.

Complex vs. Simple Carbohydrates

Not all carbohydrates are created equal, and understanding the difference is vital for effective nutrient timing. Below is a comparison of their characteristics and best uses for muscle building.


Feature	Complex Carbohydrates	Simple Carbohydrates
Digestion Rate	Slow and steady digestion.	Rapid digestion.
Energy Release	Provides sustained energy over a longer period.	Offers a quick burst of energy.
Nutrient Density	High in fiber, vitamins, and minerals.	Often low in fiber and nutrients.
Ideal Timing	Meals consumed several hours before workouts or for general daily energy.	Immediately before, during, or right after a workout.
Examples	Oats, brown rice, sweet potatoes, quinoa, legumes.	Fruits (like bananas), fruit juice, white rice, sports drinks.

Conclusion: Fuel Your Gains, Don't Fear the Carbs

For those aiming to build muscle effectively, the question of whether to eat more carbs is not a simple yes or no; it's about eating the right amount at the right time. Carbohydrates are the primary fuel source for high-intensity training and play a critical, complementary role to protein by sparing muscle tissue from being used for energy. Without adequate carb intake, your workout performance will suffer, and your recovery may be impaired, ultimately hindering muscle growth. Embracing a balanced approach that includes strategic carbohydrate timing and choosing nutrient-dense complex carbs for sustained energy will provide the optimal fuel for your body to grow stronger and recover faster. For best results, pair your carbs with adequate protein throughout the day, especially around your training sessions, and adjust your intake based on your training volume and specific goals.

For more in-depth nutritional guidance, consider consulting an expert. The International Society of Sports Nutrition provides excellent resources for those seeking to optimize their diet. International Society of Sports Nutrition

Frequently Asked Questions

The amount of carbohydrates you need depends on your body weight, activity level, and training intensity. A common recommendation for strength-training athletes is 4–7 grams of carbohydrates per kilogram of body weight per day. Those with very high training volumes may require more, while less active individuals can consume less.

Inadequate carbohydrate intake can compromise your high-intensity workout performance by limiting glycogen stores. It also increases the risk of your body breaking down muscle tissue for energy, which hinders muscle growth and repair.

While low-carb diets can be effective for weight loss, research suggests they are generally inferior to high-carb diets for maximizing muscle strength and mass gains in resistance-trained individuals. Low glycogen availability can impair training volume and intensity.

Focus primarily on complex carbohydrates like whole grains, sweet potatoes, and legumes for sustained energy. Use simple, fast-digesting carbs like fruits, rice cakes, or a sports drink strategically around your workouts for quick fuel and recovery.

No, consuming carbohydrates will not automatically cause you to gain body fat. Weight gain is primarily determined by a total calorie surplus. When consumed as part of a balanced, calorie-controlled diet that supports your training, carbohydrates are vital for fueling performance and growth, not fat storage.

While meeting your overall daily carb needs is most important for general muscle gain, timing them around workouts becomes more critical for high-volume or very active individuals. Consuming carbs pre- and post-workout can improve performance and accelerate recovery.

Yes, consuming a combination of carbohydrates and protein post-workout is highly recommended. This synergistic effect accelerates glycogen replenishment, stimulates muscle protein synthesis, and enhances overall recovery, promoting greater muscle repair and growth.