These Are the Essential Nutrients for Muscle Growth

Building muscles enhances strength and overall athletic performance, yes, but muscle health benefits everyone—not just athletes. Strong muscles support joints, strengthen the heart and bones, and maintain a healthy metabolism. That's why regular muscle training is crucial. Here’s why protein is essential for muscle growth and, according to nutrition scientist Dr Georg Abel, which other nutrients you need to promote muscle development.

What Are Muscles?

When people talk about muscles, they often refer to skeletal muscles. These are the muscles that enable voluntary movement, maintain posture, protect organs, and generate heat. Examples include our arm or leg muscles. There's also smooth muscle found in organs and blood vessels, which operates involuntarily. This article will refer only to skeletal muscles.

Important: To understand how nutrients aid muscle growth, it's crucial to know muscle composition. Skeletal muscles consist of connective tissue, blood vessels, nerves, and muscle fibres (long muscle cells). Fundamentally, muscles are about 75% water and 20% protein, with the remaining 5% comprising fats, carbohydrates (glycogen), and minerals.

What's Striated Muscle?

The term "striated muscle" comes from the structure of muscle cells. Each muscle fiber is longitudinally traversed by fine protein filaments called actin and myosin filaments. Under a microscope, actin filaments appear light, and myosin filaments appear dark. This creates the striated appearance. Each segment is called a sarcomere, allowing muscle cells to contract and cause muscle tension.

For muscles to function (contract and relax), they rely on a specific energy carrier: adenosine triphosphate (ATP). ATP is primarily produced from glucose and fatty acids using oxygen (aerobic metabolism).

Which Nutrients Are Essential for Muscle Growth?

Based on the structure and function of muscles, it becomes clear that muscle growth and movement require proteins (amino acids), fats (fatty acids), carbohydrates (glucose), and specific minerals. But how exactly does muscle building work?

Simply put, muscle growth (hypertrophy) occurs when:
- Enough protein is consumed through diet, and
- Growth stimuli are provided through muscular strain.

Both stimulate muscle protein synthesis, leading to larger and thicker muscle fibers and the formation of new fibers. The combination of adequate protein intake and strength training is the most efficient strategy for building muscle mass according to current research, though additional factors must be considered.

Micronutrients for Muscle Growth and Function

In addition to energy intake and macronutrients, micronutrients like vitamins and minerals are crucial for muscle growth. They play significant roles in energy metabolism, muscle growth, and recovery. They are also involved in oxygen transport, bone health maintenance, and immune system stimulation.

According to Dr Georg Abel, one common mistake is focusing too much on protein and carbs—while forgetting that regular training also increases your need for micronutrients.

For example:

Your diet directly impacts muscle growth, alongside genetics, hormones, and training. A balanced diet with fruits, vegetables, whole grains, and quality protein and fat sources supports muscle growth.

Good to know: A daily nutrient boost like AG1 can support nutrient intake, containing protein, vitamins, minerals, gut bacteria, and natural botanicals, including essential micronutrients for energy metabolism² and muscle recovery.³

Why is it important for athletes to supplement with micronutrients daily—not just occasionally?

Unlike macronutrients, micronutrients don’t work instantly—their impact often comes with consistent intake. “Many micronutrients can only be stored by the body for a limited time,” explains Dr Georg Abel. “That’s why a daily supply is key for optimal performance.”

When you train regularly, your needs increase: your energy metabolism runs at full speed, recovery has to be supported, and your immune system is under more pressure. And let’s not forget your gut health—not only is it a key part of your immune system, it also plays a crucial role in absorbing nutrients.

If you push your body regularly, you should also fuel it regularly with what it needs.

How Much Protein for Optimal Muscle Growth?

To build muscle mass, you need adequate protein intake. Proteins are essential for many bodily functions, including bones, hormones, the immune system, blood clotting, and energy metabolism. It's particularly important to consume enough protein during periods of high physical activity.

For adults who rarely or never exercise, the minimum intake is 0.8 grams per kilogram of body weight per day. For those exercising at least five hours a week, the requirement increases. Estimates suggest athletes may need 1.2 to 2.0 grams per kilogram of body weight per day, depending on the sport, training condition, and goals.

Protein: Is More Always Better?

A comprehensive study of 49 studies involving 1,863 participants found that the optimal protein intake for the greatest muscle mass gain is 1.6 grams per kilogram of body weight per day. Exceeding this intake likely offers no additional benefit.

Beyond quantity, the quality of protein and timing of intake are crucial. While the best protein source for muscle growth remains unclear, ensuring a diet that includes all essential amino acids is key. Whether from meat, cheese, eggs, soy, or peas, your choice of protein should be balanced and varied.

Essential Amino Acids for Muscle Growth

Just as with micronutrients, essential amino acids are crucial for protein synthesis, as your body cannot produce them in sufficient amounts. The nine essential amino acids are:
- Phenylalanine
- Valine
- Tryptophan
- Threonine
- Isoleucine
- Methionine
- Histidine
- Leucine
- Lysine

Animal-based foods often provide all essential amino acids, but you can still meet your protein needs with a vegan diet. You don't need to consume all amino acids in one meal; distributing them throughout the day is sufficient. Ensure a varied diet, combining different protein sources and using mostly whole foods to meet your protein requirements, especially when engaging in sports.

Utilising the Anabolic Window for Muscle Growth

When it comes to the timing of protein intake and the so-called anabolic window, research is somewhat ambiguous. It is often recommended to consume protein within a 2-hour window after exercise. However, studies show varying results, suggesting the optimal time for protein intake might depend on individual preferences, as benefits can arise from consuming protein either before or after training.

The anabolic effect of training lasts at least 24 hours but diminishes over time. Muscle protein synthesis remains elevated during this post-exercise recovery phase. Thus, protein intake multiple times a day (three to four times) is advised. Opt for easily digestible proteins before training and slower digesting proteins afterward.

Risks of Excessive Protein Intake

Some studies suggest that extreme athletes might benefit from consuming up to 3 grams of protein per kilogram of body weight per day. However, there is a concern that a consistently high protein intake can strain the kidneys and cause constipation. The long-term health effects of a high-protein diet are not well-researched.

If you plan to adopt a very high-protein diet (over 2 g/kg BW/day), it's advisable to regularly check your kidney function and consult with a healthcare provider. Additionally, ensure adequate hydration to avoid further kidney strain.

Carbohydrates and Fat: How Much Do You Need to Build Muscle?

In addition to protein, it's essential to consume an adequate amount of carbohydrates and fats for muscle growth.

Carbohydrates are the primary energy source during strength training. A lack of energy can negatively impact your workout, reducing the muscle growth signals. Experts recommend a carbohydrate intake of 4 to 7 grams per kilogram of body weight per day (or 50 to 60% of your daily calories) for muscle building.

Fats are also crucial for energy in sports. Approximately 20 to 35% of your daily calories should come from healthy fats. Your body needs fats to produce hormones and absorb certain vitamins (fat-soluble vitamins A, D, E, and K). The type of fats you consume can influence muscle mass. Some studies suggest that polyunsaturated omega-3 fatty acids promote muscle growth, while saturated fats may lead to increased body fat.

During muscle-building phases, maintain a moderate calorie surplus of about 350 to 400 extra calories per day. If muscle growth is slow or you're training at very high intensity, you can increase this to up to 950 additional calories per day.