Proteins and amino acids: muscles, collagen and regeneration

1. Complete protein profiles and their usefulness

For effective muscle synthesis, we need the full spectrum of essential amino acids in the right proportions. The quality of a protein is often described by its biological value (BV), which indicates how well the body uses it – but today the DIAAS index is increasingly used to measure digestibility more accurately.

Animal resources

• Eggs – a reference source of protein with a favourable ratio of essential amino acids
• Whey – a fast-digesting protein rich in BCAAs, suitable after exercise
• Fish – a quality source of protein; Fatty species (salmon, sardines, mackerel) also contain omega-3 fatty acids with an anti-inflammatory effect
• Poultry – lean meat with a high protein content and low fat
• Beef – a source of protein, creatine and iron, which supports energy production
• Dairy products – contain casein, which is digested more slowly and ensures a steady supply of amino acids

Note: Milk proteins, especially casein, are not suitable for everyone. They can cause digestive problems or discomfort in sensitive individuals, so alternative sources of protein are more suitable in these cases.

Plant Resources – Challenges and Solutions:

Challenges:

• Incomplete amino acid profiles – leucine, lysine or methionine are often missing
• Lower bioavailability – due to phytates, lectins and fibre
• Larger amounts are needed – to achieve the same amount of EAA as with animal sources

Solutions:

• Combining legumes and cereals (e.g. rice + beans, lentils + oats) to complete the profile
• Quinoa, amaranth and soybeans – among the most complete plant sources
• Spirulina and chlorella – high protein content, but imperfect ratio; Best combined with other sources
• Fermentation (e.g. tempeh) – improves digestibility and reduces antinutrients
• Supplementation with essential amino acids (EAAs) as needed

Note: With plant-based protein sources, a combination of different foods is key to provide the full spectrum of amino acids.

Practical comparison (~10 g of essential amino acids)

• 100 g of beef (~26 g of protein = ~10 g EAA) → an optimal ratio of amino acids, enough leucine, almost no carbohydrates
• 500 g cooked quinoa + legumes (~30 g protein = ~10 g EAA) → high in carbohydrates (~60–70 g) and a less favorable amino acid ratio, often not enough leucine

Note: Plant sources can provide EAA, but digestibility may be lower and often contain less leucine for optimal muscle synthesis – so combining or supplementing with EAA is important.

Advantages of free EAAs in a good ratio

• Rapid increase in the level of amino acids in the blood
• High bioavailability
• Negligible energy value and no digestive burden
• Balanced ratios to support muscle synthesis

Vegetarians and vegans can achieve adequate amino acid intake with proper planning – the key is to combine different foods and supplement with EAA if necessary.

More important than a single large intake is the distribution of protein throughout the day.

2. Support collagen synthesis with an optimal combination of amino acids

Collagen makes up about 30% of all proteins in the body and is crucial for the structure of the skin, joints, bones and blood vessels. After the age of 25, its formation gradually decreases (by 1–2% per year). Certain amino acids and key cofactors are required for synthesis.

The main amino acids for collagen:

• Glycine – the basic building block, represents about a third of the collagen structure
• Proline – contributes to the stability and strength of fibers
• Lysine – enables the formation of cross-links for collagen strength
• Arginine, ornithine and glutamine – metabolic precursors that support the formation of proline and regeneration processes

Key cofactors:

• Vitamin C – necessary for the hydroxylation of proline and lysine, without it collagen synthesis does not take place properly
• Zinc, manganese and copper – minerals involved in enzymatic processes and the structure of connective tissue
• Vitamin B6 – participates in the metabolism of amino acids

Natural sources to support collagen synthesis:

• Bone broth – a source of collagen peptides and amino acids (glycine, proline)
• Gelatin – contains collagen peptides, which are easier to digest than non-hydrolyzed collagen
• Berries and other colorful fruits – rich in vitamin C, anthocyanins and proanthocyanidins, which protect and stabilize collagen fibers
• Green leafy vegetables – an additional source of vitamin C and antioxidants

Warning: Heavy metals (e.g. lead, cadmium) may accumulate in the bones of animals. Therefore, when preparing bone broth, it is recommended to use bones from proven and high-quality sources.

A balanced combination of amino acids along with vitamin C and minerals can help maintain elastic skin and support joints; Effects vary between individuals.

3. Essential Amino Acids (EAA) Strategy for Maximum Results

Professional basis (ISSN, 2023):
The International Association of Sports Nutrition states that free EAAs rapidly increase plasma levels and stimulate muscle protein synthesis (MPS). The effect does not require non-essential amino acids (NEAAs), it is detectable already at doses of ~1.5–3 g, while plateau occurs at 15–18 g. Aging muscles need a higher proportion of leucine, and EAAs are especially useful in calorie deficits and in populations with “anabolic resistance”.

Advantages of free EAAs:

• rapid increase in plasma levels of amino acids → stimulation of MPS
• high bioavailability and low digestive load
• Precise amino acid ratio, possible adaptation of goals (e.g. more leucine in the elderly)
• lactose/gluten free, suitable for sensitive people

Key findings (ISSN, 2023):

• Free EAAs are more effective at stimulating MPS than the same amount of conventional proteins (e.g., from protein powders).
• The effect occurs quickly due to the rapid increase in the level of EAA in the blood.
• Effective doses: already about 1.5–3 g trigger MPS, and at 15–18 g the effect reaches a plateau.
• In the elderly, a higher leucine content is key to overcoming anabolic resistance.
• During times of caloric deficit, the need for EAA increases; When deficient, the body breaks down muscles to supply other tissues.

When we talk about “enough protein”, we really mean an adequate intake of essential amino acids. Free EAAs allow for precise dosing and rapid absorption, which research associates with greater MPS stimulation than the same amount of conventional proteins.

Recent research (Church et al., 2024) shows that as little as 3.6 g of an EAA composition with a high proportion of leucine can increase muscle protein synthesis by up to 45% in the elderly, which supports our recommendations on the effectiveness of low doses.

4. Support with essential cofactors for amino acid metabolism

For optimal functioning in metabolic pathways, amino acids need additional substances – vitamins, minerals and enzymes that enable their conversion and effective use in the body.

Key cofactors:

• Vitamin B6 (pyridoxal phosphate) – cofactor in enzymes for amino acid metabolism
• Magnesium – participates in hundreds of enzymatic reactions important for energy and protein synthesis
• Zinc – necessary for protein synthesis and tissue healing
• Iron and vitamin C – essential for collagen formation (hydroxylation of proline and lysine)
• Vitamin D – regulates calcium metabolism and supports muscle function
• Manganese and copper – participate in enzymes that build and stabilize connective tissue
• Omega-3 fatty acids – support anti-inflammatory balance and cell membrane health, which indirectly improves amino acid utilization

Digestion and absorption:

• Proteins from food or powders – to break down, they need stomach acid and digestive enzymes to release individual amino acids.
• Free amino acids – are absorbed directly and therefore do not need digestive breakdown; This makes it more accessible to the body faster and easier.

The effective use of amino acids in the body depends on the appropriate cofactors, and in the case of proteins from food, also on good digestion, which releases individual building blocks.

5. Hydration and electrolytes for the transport of amino acids

Water is the basic medium of all metabolic processes – it enables the transport of amino acids into cells, the removal of metabolic waste and the normal functioning of muscles. Even mild dehydration can have a significant impact on performance and recovery.

Recommendations for optimal hydration:

• Daily intake: about 35–40 ml of water per kg of body weight
• During exercise: additional 500-750 ml/hour, depending on intensity and ambient temperature
• Before training: 500 ml 2 hours before training
• During exercise: smaller, regular sips to maintain balance
• After exercise: replace lost fluids and electrolytes

Even about 2% of body fluid loss can reduce physical performance by 10-15% and significantly slow down regeneration.

6. Sleep and regeneration for muscle growth

During sleep, the largest proportion of muscle synthesis and the release of growth hormone takes place, so quality sleep is one of the key foundations of regeneration.

How to Optimize Sleep for Muscle Growth:

• 7-9 hours of quality sleep – most regenerative processes take place at night
• Deep sleep phases – associated with the release of growth hormone (GH) and insulin-like growth factor 1 (IGF-1)
• Supplement EAA before bed – may support an even supply of amino acids during nighttime recovery
• Dark and cool bedroom – promotes sleep quality and renewal
• Regular sleep rhythm – supports hormonal balance

Lack of sleep can significantly reduce muscle synthesis (up to 20% in some studies; Saner et al., 2020) and slows down regeneration, which is also confirmed by reviews on the role of sleep in muscle repair (Dattilo et al., 2011).

7. How stress management supports hormones and muscle growth

Prolonged stress increases cortisol levels, which promotes the breakdown of muscle tissue and inhibits the synthesis of new proteins. Therefore, stress management is an important factor in supporting hormonal balance and the efficient use of amino acids.

Strategies to reduce catabolic stress:

• Meditation (10–20 minutes a day) – proven to reduce stress responses of the nervous system
• Breathing exercises – activate the parasympathetic nervous system and promote calming
• Yoga – combines movement and relaxation and regulates hormonal responses
• Nature – even a short contact with the natural environment can reduce cortisol levels
• Social contacts – support the release of oxytocin, which has an anti-stress effect

Stress management supports anabolic processes and can improve the efficiency of amino acid use and regeneration.

8. Training at home – how muscle fatigue promotes growth

Muscle growth (hypertrophy) occurs when muscle fibers undergo enough mechanical stress. The key is to bring the muscle to muscle fatigue or exhaustion – then each fiber must produce more force to complete the movement, which puts additional strain on the muscle and promotes growth.

Key takeaway: Muscles grow because of fatigue – not just from lifting heavy weights.

Strategy 1: More repetitions with your own weight

• Perform the exercises at a normal pace, but repeat until muscle fatigue
• Research shows that lighter loads with more reps can promote comparable growth than heavy weights
• Rule: Continue until you can no longer do the repetition with the correct technique

Strategy 2: Super-slow pace

• 3 seconds to lift (concentric phase)
• 3 seconds for descent (eccentric phase)
• Reduced risk of injury and better control of the technique
• More time under tension → a stronger stimulus for muscle growth

An example of a 20-minute home workout to muscle fatigue

Warm-up (2-3 min): dynamic stretching, arm circles, light jogging in place

Main part (15 min):
Perform each exercise until muscle fatigue, but always maintaining proper technique.

• Push-ups (classic or customized on the knees)
• Squat under your own weight (if desired, hold below for 2-3 seconds)
• Drop steps (alternating, with slow lowering and raising)
• Plank (30-90 seconds or to the point where you can no longer align properly; variations if desired – side plank)
• Triceps dip (on the table or edge of the couch)

Do 3 rounds, rest 30-60 seconds between exercises, 60-90 seconds between circles.

Cool down (2 min): stretch your legs, back and shoulders

Even 20 minutes of targeted training at home can trigger a similar muscular response to a workout at the gym — if the workout is done consistently and to the point of fatigue.

9. Creatine and L-carnitine – energy, regeneration and muscle mass in support of EAA

Creatine and L-carnitine complement the effect of essential amino acids (EAAs) and together provide holistic muscle support. Creatine increases ATP stores and allows for more repetitions in training, leading to a greater stimulus for hypertrophy and long-term muscle growth. L-carnitine, on the other hand, promotes the use of fats as fuel, reduces muscle damage after exercise and supports mitochondrial function – thus indirectly enabling better regeneration and more quality training.

Why together?

• Creatine is key to explosive strength and muscle mass gain.
• L-carnitine helps with endurance, recovery, and long-term performance.
• EAAs provide the building blocks without which muscle growth and restoration are impossible.

Practical:

• Creatine: 3–5 g per day, regularity is more important than timing of ingestion.
• L-carnitine: 1–2 g daily, often before exercise or distributed throughout the day.
• EAA: around exercise or evenly throughout the day for a steady supply of amino acids.

Together, they form a powerful combination: creatine promotes muscle growth and strength, L-carnitine improves regeneration and endurance, and EAAs provide the building blocks for renewal and vital aging.