Whether you’re at the beginning of your fitness journey, a die-hard gym-goer, or a serious athlete, the mission to improve yourself never stops. While training and daily nutrition build the foundation for success, incorporating a key nutritional powerhouse may help you go even further: essential amino acid (EAA) and branched-chain amino acid (BCAA) supplements. These building blocks of protein are crucial for muscle growth, recovery, and endurance, making them a great addition to any fitness routine.

What Are Essential Amino Acids?

Essential amino acids are nine amino acids that the body needs for many functions, including muscle support, but cannot produce on its own. These include histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. Unlike non-essential amino acids, which the body can create on its own, EAAs must be obtained through diet or supplementation. They play a critical role in muscle repair, energy production, and overall bodily functions. Among them, branched-chain amino acids (BCAAs)—leucine, isoleucine, and valine—are best known for their muscle-building and muscle-repair benefits.

What Are BCAAs? 

Branched-Chain amino acids are made up of 3 essential amino acids that play a key role in muscle growth, repair, and recovery. These 3 amino acids are Leucine, Isoleucine, and Valine. The most researched and ideal ratio to consume BCCAs is 2:1:1, which means there should be a ratio of twice as much Leucine as there is Isoleucine and Valine. Leucine is considered the most important of the three BCAAs for initiating muscle protein synthesis, which is required for muscle building. A dose of 2-3g Leucine is generally considered best to stimulate muscle protein synthesis.

Benefits Of Amino Acids For Fitness

1. Boost Muscle Growth

One of the biggest advantages of EAA and BCAA supplementation is its ability to increase muscle protein synthesis, the process responsible for muscle growth and repair. Leucine, a key component of BCAAs, triggers the mTOR pathway, which kickstarts muscle-building mechanisms.¹ Studies have shown that consuming BCAAs or EAAs before, during, or after workouts maximizes muscle adaptation and promotes faster recovery.² Clinical research has shown that as little as 6 grams of EAAs orally consumed can stimulate net muscle protein balance post-resistance exercise.³  

2. Prevent Muscle Breakdown and Accelerate Recovery 

After an intense workout, muscle breakdown and soreness are inevitable. EAAs and BCAAs help speed up the repair process, reducing the muscle soreness that can typically happen the day after intense exercise.⁴ Furthermore, BCAAs have been shown to preserve muscle mass under intense exercise and dieting that can cause protein breakdown and muscle wasting.⁵ Post-workout BCAA intake helps prevent muscle breakdown (by providing amino acids that counteract protein degradation. Think of BCAAs as protectors for your muscles! That means you can recover faster and have less muscle soreness between challenging workouts to support muscle building.

3. Raise Endurance and Fight Fatigue

Long workouts or endurance cardio can drain glycogen stores, leading to fatigue as your body starts to feel like it's running out of gas. EAAs and BCAAs help fight fatigue by reducing the amount of the amino acid tryptophan getting into the brain as well as helping reduce the level of serotonin in the brain, both of which can raise your feelings of fatigue.⁶ This means you can push through more intense weightlifting, running, or cardio workouts without hitting the wall as quickly. Plus, when your body depletes the stored glycogen it used for energy during exercise, BCAAs can still work to fuel your muscles.⁷ BCAAs can act as an energy source that can be directly utilized by muscles, helping you push through workouts with more energy, endurance, and less fatigue. 

4. Help Preserve Muscle When Dieting 

One of the biggest concerns when dieting can be muscle loss. When you reduce your calorie intake, your body may start breaking down muscle tissue for energy, leading to a slower metabolism and decreased strength. Plus, lower calories can often lead to low energy levels, making workouts feel more exhausting than usual. EAAS and BCAAs help stimulate muscle protein synthesis, ensuring your body continues to build and maintain lean muscle even when you cut your calories.⁸ Using a BCAA supplement as part of your nutritional plan while dieting supports muscle retention, assisting your body in maintaining lean muscle even in a caloric deficit. Other clinical research has also shown that low-dose leucine-enriched EAAs can promote a positive net muscle protein balance (MPB). This research compared various leucine-enriched EAAs doses (1.5g, 3g, and 6g) to 20g whey and 40g whey protein. The 3g and 6g leucine-enriched EAAs provided a similar initial and 4-hour MPB as compared to a single serving of 20g whey protein and 40g whey protein, respectively.⁹ 

5. Help Reducing Hunger and Cravings

Sticking to a diet can be difficult when hunger and cravings hit. BCAAs can help curb appetite by influencing brain chemicals that regulate satiety and hunger. Leucine has been shown to modulate the release of hormones like ghrelin (the hunger hormone) and leptin (the satiety hormone), helping you feel fuller for longer.¹⁰

Additionally, BCAAs help support stable blood sugar levels, reducing energy crashes that often lead to sugar cravings and binge eating. This can be especially helpful for those following low-carb or intermittent fasting diets.

6. Easy Absorption Makes EAAs and BCAAs Ideal for Workouts

Unlike whole protein sources, which require digestion before breaking down into amino acids, BCAA and EAA supplements are already in pure form, allowing for quick absorption. This ensures that muscles get the nutrients they need almost immediately, making them ideal for before, during, and post-workout supplementation. Whole protein powders like whey protein are best suited for post-workout to get an even broader range of non-essential and essential amino acids for recovery or as a supplement to boost protein intake during your day.¹¹ 

How to Use EAAs and BCAAs

To maximize the benefits of EAAs and BCAAs, timing and dosage matter:

• Pre-Workout: Taking before exercise primes the body for muscle synthesis and energy production. EAAs and BCAAs can also be combined with caffeine to make a higher energy pre-workout. 
• Intra-Workout: Use during training to help sustain performance and prevent muscle breakdown.
• Post-Workout: EAAs and BCAAs right after a workout are rapidly absorbed and help prevent delayed muscle soreness and boost muscle repair and recovery.
• Recommended Dosage: 5 grams per serving of BCAAs is ideal for most workouts or use post-workout, depending on individual needs and training intensity. We recommend sticking to the 5–10 gram range or BCAAs or EAAs in total between use before or during a workout and post-workout. If you are using EAAs, we recommend making sure to get at least 5 grams of BCAAs as part of the total EAAs consumed to support muscle repair and recovery. 
• Stacking with Other Supplements: EAAs pair well with most other supplements, including carbohydrates, energy supplements like caffeine, hydration supplements such as electrolytes, or even protein powders to enhance performance and recovery.

Takeaway

Whether you're a seasoned athlete or just starting your fitness journey, incorporating essential amino acid and branched chain amino acid supplements can help you get more from your workout routine. From muscle growth and recovery to endurance, dieting, and energy levels, EAAs and BCAAs can help you train harder and recover faster to support your fitness goals!

References:

1. Drummond, M. J., Dreyer, H. C., Fry, C. S., Glynn, E. L., & Rasmussen, B. B. (2009). Nutritional and contractile regulation of human skeletal muscle protein synthesis and mTORC1 signaling. Journal of Applied Physiology, 106(4), 1374-1384.
2. Blomstrand, E., Eliasson, J., Karlsson, H. K., & Kohnke, R. (2006). Branched-chain amino acids activate key enzymes in protein synthesis after physical exercise. Journal of Nutrition, 136(1), 269S-273S.
3. Wilkinson, S.B., et al. (2013) The effect of different protein sources on muscle protein synthesis in young in.  American Journal of Clinical Nutrition, 97(6), 1220-1228
4. Jackman, S. R., Witard, O. C., Jeukendrup, A. E., & Tipton, K. D. (2010). Branched-chain amino acid ingestion can ameliorate soreness from eccentric exercise. Medicine and Science in Sports and Exercise, 42(5), 962-970.
5. Gualano, B., de Salles Painelli, V., Roschel, H., Lugaresi, R., D'Amelio, P., & Lancha, A. H. (2012). Leucine supplementation in elderly: Effects on muscle protein synthesis and functional performance. Journal of Aging and Physical Activity, 20(4), 497-508.
6. Blomstrand, E. (2006). A role for branched-chain amino acids in reducing central fatigue. Journal of Nutrition, 136(2), 544S-547S.
7. Shimomura, Y., Yamamoto, Y., Bajotto, G., Sato, J., Murakami, T., Shimomura, N., & Mawatari, K. (2004). Nutraceutical effects of branched-chain amino acids on skeletal muscle. Journal of Nutrition, 134(6 Suppl), 1583S-1587S.
8. Hector, A. J., & Phillips, S. M. (2018). Protein recommendations for weight loss in elite athletes: A focus on body composition and performance. International Journal of Sport Nutrition and Exercise Metabolism, 28(2), 170-177.
9. Churchward-Venne, T. A., Breen, L., Di Donato, D. M., Hector, A. J., Mitchell, C. J., Moore, D. R., & Phillips, S. M. (2014). Leucine-enriched essential amino acid ingestion results in greater muscle protein synthesis than ingestion of leucine alone in young men. Journal of Nutrition, 144(5), 665-673.
10. Gualano, B., Bozza, T., Lopes de Campos, P., Roschel, H., dos Santos, M. C., Marquezi, M. L., & Lancha Junior, A. H. (2011). Branched-chain amino acids supplementation enhances exercise capacity and lipid oxidation during endurance exercise after muscle glycogen depletion. Journal of Sports Medicine and Physical Fitness, 51(1), 82.
11. Tipton, K. D., Ferrando, A. A., Phillips, S. M., Doyle Jr, D., & Wolfe, R. R. (2001). Postexercise net protein synthesis in human muscle from orally administered amino acids. American Journal of Physiology-Endocrinology and Metabolism, 280(5), E733-E743.