Contents
What is isoleucine?
Isoleucine is an essential amino acid. This means the body cannot produce it, therefore you need to include it in your diet. This amino acid has many roles within the human body. It is best known for its ability to support blood clotting at wound sites and assisting with muscle tissue repair. L-isoleucine can also help to boost energy levels and improve stamina.
Consequently, this is a widely used amino acid supplement for body builders and endurance athletes1. Not only does it provide an added energy boost, it also helps the body to repair faster following periods of strenuous physical activity2.
Uses of isoleucine
Isoleucine is one of three specialised amino acids known as branched-chain amino acids (BCAAs). This group also includes leucine and valine. Branched-chain amino acids assist with muscle recovery following exercise.
The body breaks down isoleucine within the muscle tissue to generate energy. Additionally, this amino acid helps to regulate blood sugar levels to stabilise energy levels. Isoleucine significantly increases the body’s ability to utilise glucose during exercise. However, it does not promote the synthesis of glycogen.
Deficiency symptoms
People with low levels of this essential amino acid will experience symptoms similar to hypoglycaemia. This can include dizziness, fatigue, headaches, confusion, irritability, and depression. People with a balanced diet rarely have a deficiency in this amino acid.
Natural sources of isoleucine
High protein foods are typically rich in this essential amino acid. Meat, fish, eggs, nuts, seeds, and pulses are all good sources of isoleucine. However if you have a low-protein diet or exercise a lot, you might need to consider taking supplements. Many dietary supplements include this amino acid.
However, it is important not to take isoleucine alone and it should always be paired with valine and leucine for the best results. The recommended dosage ratio is 1 milligram of isoleucine together with 1 milligram of valine and 2 milligrams of leucine.
Scientists think that this is the best ratio for optimal absorption. There are many supplements that contain all BCAAs in the correct ratios for convenience.
Prior to taking any supplement it is important to first consult with a medical practitioner. For people with impaired kidney or liver function isoleucine may worsen these conditions.
References
- Bajotto, G. et al. (2011). Effect of BCAA Supplementation During Unloading on Regulatory Components of Protein Synthesis in Atrophied Soleus Muscles. European Journal of Applied Physiology. Volume 111, Issue 8, pp. 1815-28 ↩
- Sharp, C. and Pearson, D. (2010). Amino Acid Supplements and Recovery from High-Intensity Resistance Training. Journal of Strength and Conditioning Research. Volume 24, Issue 4, pp. 1125-30 ↩