Why Protein Is Important For Gains
Written by Mackayla Brennan — Content Writer & Nutrition Student
If you're training consistently but not seeing the muscle growth you're working toward, your protein intake might be the missing piece. Protein is the foundation of muscle repair, growth, and long-term physical performance — but understanding how much you need, when it matters most, and what quality looks like can make a significant difference to your results.
What Is Muscle Protein Balance?
Skeletal muscle is not a static tissue. It is constantly cycling between two states:
- Muscle protein synthesis (MPS) — where new muscle protein is being built
- Muscle protein breakdown (MPB) — where existing muscle protein is being broken down
The balance between these two processes determines whether you gain, maintain, or lose muscle over time.
Negative protein balance occurs when breakdown exceeds synthesis. This can happen during periods of low protein intake, illness, prolonged rest, or significant calorie restriction. Over time, a consistently negative protein balance leads to muscle loss.
Positive protein balance occurs when synthesis exceeds breakdown. This is the state required for muscle growth and recovery, and it is stimulated by two key factors: resistance training and adequate dietary protein intake.
The goal for any physically active person is to spend as much time as possible in a positive protein balance — and that starts with what you eat.
How Much Protein Do You Actually Need?
The standard Recommended Dietary Allowance (RDA) for protein is not designed with muscle growth or athletic performance in mind. For physically active individuals, leading sports nutrition organisations recommend significantly higher intakes.
- The Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine jointly recommend 1.2–2.0g of protein per kilogram of body weight per day for those engaged in regular physical activity.
- The International Society of Sports Nutrition (ISSN) recommends 1.4–2.0g per kilogram of body weight per day to support muscle adaptation, exercise recovery, and performance.
- For those focused specifically on muscle growth, research supports intakes toward the higher end — around 1.6–2.2g per kilogram per day.
To put that in practical terms, a 75kg person training for muscle growth may need between 120g and 165g of protein daily to fully support their goals. For many people, consistently hitting that target through whole food alone is challenging — which is where a high-quality protein supplement can help fill the gap.
Why Protein Matters More When You Train
Resistance training creates microscopic tears in muscle fibres. This damage is intentional — it signals the body to repair and reinforce the affected tissue, resulting in stronger, larger muscles over time. But this repair process depends entirely on the availability of amino acids from dietary protein.
Without adequate protein, the body cannot complete this repair process efficiently. The result is slower recovery, prolonged muscle soreness, and reduced adaptation — meaning the hard work you put in at the gym produces less than it should.
Protein also plays a broader role in physical performance beyond muscle repair, including enzyme production, hormone regulation, and energy metabolism during prolonged exercise.
Protein and Ageing: Why It Becomes Even More Important Over Time
The importance of adequate protein intake does not decrease with age — it increases. Older adults face a higher risk of insufficient protein intake due to changes in appetite, digestion, and the presence of chronic health conditions.
When protein intake is consistently low in older populations, the risk of sarcopenia — age-related muscle loss — increases significantly. Sarcopenia is associated with reduced strength, impaired physical function, and a lower quality of life.
Maintaining adequate protein intake alongside regular resistance training is one of the most evidence-supported strategies for preserving muscle mass, strength, and functional independence as you age.
Protein Quality: Complete vs Incomplete Proteins
Not all protein sources are equal. Protein quality refers to a food's ability to supply the full range of essential amino acids (EAAs) your body needs but cannot produce on its own.
Complete proteins contain all nine essential amino acids in sufficient quantities. These are primarily found in animal-based foods — meat, fish, eggs, and dairy. Some plant-based sources, including soy and quinoa, also provide a complete amino acid profile.
Incomplete proteins are missing one or more essential amino acids or do not provide them in adequate amounts. Most individual plant-based foods fall into this category, including grains, legumes, nuts, and seeds. However, consuming a varied range of plant protein sources throughout the day can still meet your full essential amino acid requirements.
For those using protein supplements, prioritising sources that deliver a complete amino acid profile — whether whey-based or a well-formulated plant blend — ensures you're getting the full benefit from every serve.
The Bottom Line
Building and maintaining muscle requires more than consistent training. It requires enough dietary protein to keep your body in a positive protein balance, support the repair process triggered by resistance training, and supply the essential amino acids your muscles need to grow. Whether your goal is performance, physique, or healthy ageing, protein is one nutritional variable you cannot afford to underestimate.
Frequently Asked Questions
What is muscle protein balance and why does it matter?
Muscle protein balance refers to the relationship between muscle protein synthesis — the building of new muscle — and muscle protein breakdown. When synthesis exceeds breakdown, the body is in a positive protein balance, which supports muscle growth and repair. When breakdown exceeds synthesis, muscle loss can occur over time. Maintaining a positive protein balance through adequate protein intake and resistance training is essential for anyone looking to build or preserve muscle mass.
How much protein do I need to build muscle?
For muscle growth, most sports nutrition organisations recommend between 1.6 and 2.2 grams of protein per kilogram of body weight per day. For a 75kg person, that translates to roughly 120–165 grams of protein daily. Individual needs vary based on training intensity, age, and overall calorie intake, but consistently meeting this target is one of the most important nutritional steps for supporting muscle adaptation.
What is the difference between complete and incomplete proteins?
A complete protein contains all nine essential amino acids that the body cannot produce on its own. Animal-based foods like meat, eggs, fish, and dairy are typically complete proteins, as are plant-based sources like soy and quinoa. Incomplete proteins are missing one or more essential amino acids and include most individual grains, legumes, and nuts. Eating a variety of plant protein sources throughout the day can still provide a full essential amino acid profile.
Does protein intake become more important as you age?
Yes. As people age, the risk of insufficient protein intake increases due to changes in appetite and digestion, alongside a greater risk of age-related muscle loss known as sarcopenia. Adequate protein intake combined with regular resistance training is one of the most effective strategies for preserving muscle mass, strength, and physical independence in older adults.
Can I get enough protein from food alone, or do I need a supplement?
It is possible to meet protein requirements through whole food sources alone, but for many physically active individuals — particularly those with higher training demands or busy lifestyles — consistently hitting daily protein targets through diet alone can be difficult. A high-quality protein supplement like Protein of the Gods can be a practical and effective way to close the gap and ensure your muscles have the amino acids they need to recover and grow.
References
ADPI Protein Quality Guide Protein Quality Guide All proteins are not created equal. (n.d.). Retrieved February 19, 2026, from https://adpi.org/wp-content/uploads/2025/07/ADPI-Protein-Quality-Guide_2025.pdf
Carbone, J. W., & Pasiakos, S. M. (2019). Dietary protein and muscle mass: Translating science to application and health benefit. Nutrients, 11(5). https://doi.org/10.3390/nu11051136
Cleveland Clinic. (2022). Sarcopenia (Muscle Loss): Symptoms & Causes. Cleveland Clinic. https://my.clevelandclinic.org/health/diseases/23167-sarcopenia
Why Is Protein Important for Working Out? (2025). Biology Insights. https://biologyinsights.com/why-is-protein-important-for-working-out/
