So, can you do large amounts of cardio and grow muscle at the same time? Many believe that running will hinder strength and muscle gains. However, with proper nutrition and maximizing recovery, it is possible to successfully grow muscle while training for long-distance running.
Nutrition: The Cornerstone of Muscle Growth
The most important factors in muscle growth are a calorie surplus and sufficient protein intake. For example, a surplus of 200-400 calories along with 1 gram of protein per pound of body weight is an effective strategy to support growth. While training for my first marathon, my total energy expenditure was around 3,400 calories per day, so I consumed at least 3,600 calories to ensure muscle growth and optimal performance.
Recovery: The Unsung Hero
As training volume increases, so does the need for recovery. Combining 40+ hours of running per week with weight training demands significant attention to recovery. Sleep is crucial, as most muscle repair and adaptation occurs during rest. I aimed for 7-9 hours of sleep per night to optimize recovery and performance. Recovery nutrition also plays a key role—focusing on a balanced diet with whole foods, assorted fruits and vegetables, and minimal junk food is essential.
Macro Breakdown for Muscle Growth and Endurance
If your goal is to build muscle while performing high amounts of cardio, macronutrients become critical. My typical daily macros were:
- Protein: 225 grams
- Carbohydrates: 400 grams
- Fat: 125 grams
- Total Calories: 3,625
This approach meets protein and calorie requirements for muscle growth while providing enough energy to sustain intense cardio training.
Balancing Muscle Growth and Fat Loss
Studies indicate that you cannot simultaneously maximize muscle growth and fat loss. Significant fat loss requires a calorie deficit of 400-1,000 calories per day, which can reduce performance and may lead to loss of lean body mass (approximately 25% of total weight lost). To maintain performance during a cut, nutrient timing is essential—consume carbohydrates before and after workouts, and pair them with protein post-workout to maximize recovery.
Practical Recommendations
- If your goal is peak performance: balance your calories to meet your energy demands.
- If your goal is muscle growth: consume a modest surplus of 200 calories per day.
- If your goal is fat loss while preserving muscle: aim for a slight deficit of 200-250 calories per day, rather than an aggressive deficit of 500+ calories.
Unless using anabolic steroids or pharmaceutical cutting agents—which are not recommended—it is unrealistic to gain significant muscle and lose substantial fat simultaneously. However, with proper recovery, adequate calorie intake, and sufficient protein, it is possible to train for long-distance running and grow muscle. Running only negatively impacts muscle gains when nutrition and recovery are poorly managed.
Marcus Harris, Registered Dietitian, Pro Bodybuilder, and Marathoner
