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Can you Build Muscle and Lose Fat at the Same Time?

By Dr. Crionna Tobin, Phd, Optimum Nutrition, Head of Nutrition & Education

Key Learnings

  • The Role of Genetics: While genetics can influence your body type, it’s essential to remember that hard work and a well-structured fitness plan can often override these genetic tendencies.

  • Strength Training: Training with progressive overload, an increase in weight, sets, reps, volume, and/or intensity over time is crucial to continual progress.

  • Nutrition: Ensuring you’re in a modest calorie deficit (approx. 250 calories per day) for fat loss while consuming adequate protein, which is crucial for preserving muscle mass during the weight loss process.

  • Cardiovascular Exercise: The Fat-Burning Boost: Aim to incorporate at least 150 minutes of moderate-intensity cardio or 75 minutes of vigorous-intensity cardio into your weekly routine.

  • Sleep: The Unsung Hero: Aim for 7-9 hours of quality sleep each night.


1. The Role of Genetics
2. Strength Training
3. Nutrition
4. Cardiovascular Exercise: The Fat-Burning Boost
5. Sleep: The Unsung Hero

Building Muscle and Losing Fat

For decades, fitness enthusiasts and experts alike have debated the possibility of achieving two seemingly contradictory goals: building muscle and losing fat simultaneously. The widespread belief was that you must focus on either bulking up or slimming down. However, with advances in nutritional science and resistance training, this myth is being dismantled.

The Role of Genetics

Understanding your body type can give you valuable insights into how your genetics might influence your fitness journey. While genetics can influence your body type, it’s essential to remember that hard work and a well-structured fitness plan can often override these genetic tendencies.

Muscle Fibre Composition: Genetics also influences the different types of muscle fibre types in your body. Some people may have a higher percentage of fast-twitch muscle fibres, which are associated with explosive strength and muscle growth, while others may have more slow-twitch muscle fibres, which are geared towards endurance activities.

Fat Storage: Genetics can also dictate where your body tends to store fat. Some individuals may naturally store fat in their abdominal area, while others may store it in their hips or thighs.

While genetics do play a role, it’s essential to emphasise that everyone can make significant progress in building muscle and losing body fat with the right training, nutrition, and consistency. Genetics might set the stage, but your dedication, effort, and smart decision-making are the main actors in your fitness journey. Remember, the human body is incredibly adaptable, and with the right approach, you can achieve remarkable results.

Strength Training: Building Lean Muscle

The Power of Progressive Overload

To build muscle, you must continually challenge your muscles by increasing the intensity of your workouts over time, a concept called progressive overload. This can be achieved by increasing the amount of weight you lift, and the amount of reps and sets you do in each session4.

Compound Exercises vs. Isolation Exercises

Understanding the difference between these exercises is vital. Compound exercises, like squats, deadlifts, and bench presses, work multiple muscle groups simultaneously, leading to greater muscle engagement and growth. Isolation exercises, like bicep curls and leg extensions, focus on a single muscle group and are useful for targeting specific areas.

Designing a Strength Training Routine

A well-structured strength training program should include a mix of compound and isolation exercises. It’s important to plan your workouts to ensure all major muscle groups are worked twice per week5. This can involve splitting your workout days into upper and lower body sessions or focusing on push and pull movements. Remember, the key to building muscle is consistent, progressive overload, so continually challenging your muscles is essential for growth.

Nutrition: Next Up

The Importance of Macronutrients: Nutrition forms the part of the foundation of your fitness journey, and two key aspects play a pivotal role: being in a calorie deficit and prioritising your macronutrient or protein and carbohydrate intake.

Calorie Deficit: To lose weight, or fat mass, effectively, it’s crucial to consume fewer calories than you expend. This creates a calorie deficit, prompting your body to reduce its fat stores. While creating a calorie deficit, it’s essential to do so in a balanced and sustainable way to avoid compromising or losing any of your muscle mass. Start with a modest calorie deficit of 250 calories per day is adjust from there based on results within 1-2 weeks.

The Role of Protein: Protein serves as the building block for muscle tissue. When we consume protein, it is broken down into amino acids, which are then used by the body to repair and rebuild muscle tissue. Adequate protein intake ensures that the body has the necessary materials to maintain and potentially increase your muscle mass during a calorie deficit. Protein can also increase feelings of fullness, helping you stick to a lower calorie diet and indirectly supporting weight loss6. General protein intake guidelines recommend an intake of 1.2-2.2 grams of protein per kilo of body mass per day7, with this level of protein intake has been demonstrated as safe in healthy adults.

Timing and Types of Carbohydrates: To maximise the benefits of carbohydrates in your fitness journey, consider the timing and types of carbohydrates you consume. Consuming carbohydrates before and after your workouts can provide the energy needed for your resistance sessions exercise and support recovery after your workout6. Go for whole, unrefined carbs that are rich in fibre and nutrients, such as oats, potato, sweet potato, fruits, and vegetables as they provide sustained energy and keep you feeling full. Carbohydrate recommendations are 4-7 grams per kilo body mass per day for individuals taking part in strength training, equalling 280-490 grams of carbohydrates for a 70 kg person. Remember that individual carbohydrate needs can vary, so it’s essential to tailor your intake to your specific goals and activity level while maintaining overall nutritional balance.

In conclusion, being in a calorie deficit, consuming adequate protein, and the timing and type of carbohydrates are a vital component of a balanced diet when you aim to simultaneously build muscle and lose body fat.

Cardiovascular Exercise: The Fat-Burning Boost

HIIT vs. Steady-State Cardio

Both High-Intensity Interval Training (HIIT) and steady-state cardio have their place in a fitness regimen. HIIT, involving short bursts of intense activity followed by rest, is excellent for burning a high number of calories in a short period and can increase calories burned for hours after the workout. Steady-state cardio, like jogging or cycling at a consistent pace, is effective for building your endurance capacity. Aim to incorporate at least 150 minutes of moderate-intensity cardio or 75 minutes of vigorous-intensity cardio into your weekly routine.

Balancing Cardio with Strength Training

The key to successfully incorporating cardio into a muscle-building and fat-loss program is balance. Too much cardio can hinder muscle growth by creating too much of calorie deficit, leading to potential muscle mass loss. A good rule of thumb is to limit high-intensity cardio sessions to 2-3 times a week and focus on shorter, more intense sessions rather than long-duration cardio.

Sleep: The Unsung Hero

Sleep and Muscle Growth

Sleep plays a pivotal role in muscle growth and recovery. During sleep, your body releases growth factors and controls local inflammation which will aid in muscle repair and growth9. Additionally, adequate sleep helps regulate cortisol levels, a stress hormone that can lead to increased fat storage and muscle breakdown if not managed properly. Aim for 7-9 hours of quality sleep each night.

Protein Supplements and Muscle Building

While not a substitute for a balanced diet, supplements can support muscle building. Gold 100 % Standard Whey, Gold Standard 100 % Casein, and Gold Standard Plant Protein powders, can play a role in supporting muscle recovery and growth* by helping you to hit your daily protein targets.


The journey to simultaneously build muscle and lose body fat is a challenging but achievable goal. By understanding and applying key principles, you can effectively transform your body and reach your fitness objectives. The three main pillars to focus on are: firstly, a well-balanced nutrition plan that emphasises the right balance of macronutrients; secondly, a strategic approach to exercise that combines strength training with cardiovascular workouts, ensuring both muscle growth and fat loss; and thirdly, the often overlooked yet crucial aspects of recovery and supplementation.

*Protein supports muscle growth and maintenance in conjunction with regular resistance training.’


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  8. Kerksick, C. M., et al., (2018). ISSN exercise & sports nutrition review update: research & recommendations. Journal of the International Society of Sports Nutrition, 15(1), 38.

  9. Chennaoui, M., et al., (2021). How does sleep help recovery from exercise-induced muscle injuries?. Journal of science and medicine in sport, 24(10), 982–987.

  10. Leproult, R., et al., (1997) Sleep loss results in an elevation of cortisol levels the next evening. Sleep, 20 (10), 865–870.