Does the body produce the amino acids that an athlete needs?

December 2, 2025 •

3 min read

The human body requires 20 different amino acids to function properly, but it can only synthesize 11 of them on its own. This raises a critical question for those with high physical demands: does the body produce the amino acids that an athlete needs to perform and recover optimally?

Quick Summary

The body creates non-essential amino acids but requires nine essential amino acids from diet. Athletes must strategically consume all types to support muscle repair, growth, and energy.

Key Points

Essential vs. Non-Essential: The body does not produce the nine essential amino acids (EAAs), which must be obtained from food or supplements.
Heightened Needs: An athlete's intense training significantly increases the demand for all amino acids to facilitate muscle repair and growth.
BCAAs are Crucial: The branched-chain amino acids (leucine, isoleucine, and valine) are particularly important for muscle protein synthesis and recovery.
Dietary Foundation: A balanced diet provides the most comprehensive source of essential amino acids, with animal products offering complete protein profiles.
Supplementation Role: EAA or BCAA supplements can provide convenience and help meet specific needs, especially around training sessions, but should not replace whole foods.
Timing Matters: Distributing protein intake throughout the day and consuming it strategically around workouts can optimize muscle protein synthesis.

The Amino Acid Basics: Essential vs. Non-Essential

Amino acids are the fundamental building blocks of proteins, critical for functions from building muscle tissue to producing enzymes and hormones. For athletes, distinguishing between types is paramount, based on the body's production capabilities.

Essential Amino Acids (EAAs)

The nine essential amino acids (EAAs) cannot be synthesized by the body and must come from diet or supplements. Complete protein sources, like meat, eggs, and dairy, contain all nine. Plant-based sources can be combined for a complete profile. The nine EAAs include Histidine, Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Threonine, Tryptophan, and Valine.

Non-Essential Amino Acids (NEAAs)

The body produces non-essential amino acids from other sources, such as essential amino acids or carbohydrates. Dietary intake is not typically required for healthy individuals. The 11 non-essential amino acids are Alanine, Arginine, Asparagine, Aspartic acid, Cysteine, Glutamic acid, Glutamine, Glycine, Proline, Serine, and Tyrosine.

Conditionally Essential Amino Acids

Certain amino acids, like glutamine and arginine, become 'conditionally essential' when the body's production cannot meet demand, often during intense training, stress, or illness.

An Athlete's Unique Amino Acid Requirements

Athletes have significantly higher protein and amino acid demands than sedentary individuals, primarily for muscle protein synthesis (MPS) – the process of repairing and building muscle after exercise. Intense exercise breaks down muscle, increasing the need for amino acids for repair. Branched-Chain Amino Acids (BCAAs) – leucine, isoleucine, and valine – are key for athletes, metabolized in muscles and signaling for MPS. Leucine is a strong trigger for muscle growth.

Dietary Sources vs. Supplements

While the body produces non-essential amino acids, dietary protein is vital for obtaining EAAs. Athletes' protein needs are higher than the general population, often 1.2 to 2.0 grams per kilogram of body weight daily.

A balanced diet with high-quality protein is usually sufficient. However, supplements can be useful. EAA supplements offer a complete profile, while BCAA supplements target support around workouts. Plant-based athletes must combine sources to ensure all EAAs are consumed.

Comparison: Essential Amino Acids vs. Non-Essential Amino Acids


Feature	Essential Amino Acids (EAAs)	Non-Essential Amino Acids (NEAAs)
Source	Must be obtained through diet or supplementation	Produced by the human body
Number	9 amino acids	11 amino acids
Examples	Leucine, Lysine, Tryptophan	Alanine, Glycine, Glutamine
Athletic Importance	Critical for muscle repair, growth, and overall health	Important building blocks for body tissue
Key Consideration for Athletes	Must be consumed through diet to trigger protein synthesis	Body can produce them, but needs increase during stress

Optimizing Amino Acid Intake for Athletic Performance

Optimizing intake involves timing and distribution. Spreading protein consumption throughout the day (20-40 grams per meal) maximizes MPS. Consuming protein before or after exercise also aids recovery. Supplements can help those with high demands or restrictions, but they should complement a whole-food diet.

Conclusion: The Combined Approach

The body does not produce all the amino acids an athlete needs. The nine essential amino acids must come from diet or supplements. Intense training increases the demand for all amino acids to support protein synthesis, repair, and energy. Athletes can optimize performance by understanding these needs and managing intake through diet and potential supplements.

For more information on dietary supplements for exercise and athletic performance, consult the National Institutes of Health [ods.od.nih.gov/factsheets/ExerciseAndAthleticPerformance-HealthProfessional/].

Frequently Asked Questions

The primary difference is that the body cannot produce essential amino acids, so they must be acquired through diet, while the body can synthesize non-essential amino acids on its own.

Athletes require more amino acids to support the increased demand for muscle protein synthesis, tissue repair, and energy production that comes with intense and frequent physical training.

BCAAs are branched-chain amino acids (leucine, isoleucine, and valine). They are crucial for athletes because they are metabolized directly in muscle tissue and help trigger muscle protein synthesis, aid in recovery, and reduce fatigue during exercise.

Yes, but they must be more strategic. While most plant sources are 'incomplete' proteins, combining different plant-based foods, such as beans and rice, can provide all the essential amino acids needed for a complete profile.

No, supplements are not necessary for all athletes. Most can meet their protein and amino acid needs through a well-balanced diet. Supplements are a convenient option for those with very high demands or to address specific dietary gaps.

A deficiency in essential amino acids can impair protein synthesis, leading to issues with muscle repair, growth, and overall performance. It can also cause metabolic disorders and reduced immune function.

Conditionally essential amino acids, like glutamine and arginine, can normally be produced by the body. However, during periods of physical stress or illness, the body's need for them may exceed its production capacity, making external intake important.

Yes, timing can be important. While consistent daily intake is key, consuming protein strategically, particularly after exercise, can help maximize muscle protein synthesis and recovery.