BCAA’s – Endurance or Aerobic?

BCAA’s – what are they?

Branched chain amino acids (BCAA’s) are known mostly for people in the weightlifting or the bodybuilding industry. However could this supplement help in other sports or is it just for people who want to build muscle? This article will discuss the use of BCAA’s within different sports to see if it can give athletes an advantage or disadvantage if taking it?

BCAA’s are made up of 3 amino acids of Leucine, Isoleucine and Valine. They are essential for protein synthesis which is stimulated after exhaustive exercise (1) as well as the critical metabolic process in muscle (2, 3). The metabolic roles of Leucine include energy production and the modulator of muscle protein synthesis via the insulin signalling pathway. There is a reason to suggest that it helps maintenance of muscle mass during weight loss (4). Leucine has also been shown to help in the direct maintenance of glucose homeostasis by improving the redistribution of glucose via the glucose – alanine cycle (5).

Endurance Exercise

One way in which BCAA’s can benefit aerobic exercise is when taking this supplement pre and post race; as it can reduce muscle damage caused by prolonged exercise. There are several suggested mechanisms for how this occurs including BCAA ingestion increasing growth hormones whilst decreasing testosterone levels thus creating the ideal environment to recover (6). Another theory is the use of BCAA’s can reduce the breakdown of proteins within the muscle (6). Also taking these amino acids, it keeps the ‘muscle pool’ high which can either suppress muscle protein breakdown or replenish it quickly, allowing for a fast recovery.

Strength Exercise

BCAAs promote muscle protein synthesis (MPS). One study observed a 22% increase increase when taking the supplement when compared to a placebo (7). This means that during strength training it can help achieve results (8,9). It has been observed that one of the active components of BCAA, (Leucine) is sufficient to stimulate MPS however the other components (isoleucine, valine) help to give a greater effect. In addition to an increase in MPS it has been found to help aid recovery of muscles post workout. This is due to more protein being made available to the muscle in order for it to repair and grow.


1 – Coker, R. H., Miller, S., Schutzler, S., Deutz, N., & Wolfe, R. R. (2012). Whey protein and essential amino acids promote the reduction of adipose tissue and increased muscle protein synthesis during caloric restriction-induced weight loss in elderly, obese individuals. Nutr J, 11(1), 105.

2 – Hulmi, J. J., Lockwood, C. M., & Stout, J. R. (2010). Review Effect of protein/essential amino acids and resistance training on skeletal muscle hypertrophy: A case for whey protein.

3 – Pasiakos, S. M., McLellan, T. M., & Lieberman, H. R. (2015). The effects of protein supplements on muscle mass, strength, and aerobic and anaerobic power in healthy adults: a systematic review. Sports Medicine, 45(1), 111-131.

4 – Volek, J. S., Volk, B. M., Gómez, A. L., Kunces, L. J., Kupchak, B. R., Freidenreich, D. J., … & Kraemer, W. J. (2013). Whey protein supplementation during resistance training augments lean body mass. Journal of the American College of Nutrition, 32(2), 122-135.

5 – Hansen, M., Bangsbo, J., Jensen, J., Bibby, B. M., & Madsen, K. (2014). Effect of Whey Protein Hydrolysate on Performance and Recovery of Top-Class Orienteering Runners. International journal of sport nutrition and exercise metabolism.

6 – Carli, G., Bonifazi, M., Lodi, L., Lupo, C., Martelli, G., & Viti, A. (1992). Changes in the exercise-induced hormone response to branched chain amino acid administration. European journal of applied physiology and occupational physiology, 64(3), 272-277.

7 – Jackman, S. R., Witard, O. C., Philp, A., Wallis, G. A., Baar, K., & Tipton, K. D. (2017). Branched-chain amino acid ingestion stimulates muscle myofibrillar protein synthesis following resistance exercise in humans. Frontiers in physiology, 8, 390.

8 – Matthews, D. E. (2005). Observations of branched-chain amino acid administration in humans. The Journal of nutrition, 135(6), 1580S-1584S.

9 – Wilkinson, D. J., Hossain, T., Hill, D. S., Phillips, B. E., Crossland, H., Williams, J., … & Etheridge, T. (2013). Effects of leucine and its metabolite β‐hydroxy‐β‐methylbutyrate on human skeletal muscle protein metabolism. The Journal of physiology, 591(11), 2911-2923.