It’s no secret that protein, specifically the building blocks of proteins called amino acids, are important for building lean body mass. Your body has the ability to make some amino acids. These are called non-essential amino acids, meaning you don’t have an absolute requirement for these amino acids through diet. Another group of amino acids that your body can’t make are called essential amino acids. You need to get these in adequate amounts through diet to avoid a deficiency. Three specific essential amino acids, isoleucine, leucine, and valine, are called branched-chain amino acids because of their branched structure. If you work out, there are some reasons to make sure you’re getting enough of these in your diet. Here’s why.
What Are Branched Chain Amino Acids and Why You Need Them if You Exercise
After doing a strength-training workout, your muscles go into “repair and recovery mode.” To adequately recover, grow and become firmer and stronger, muscles need amino acids, especially the essential ones your body can’t make. Branched-chain amino acids (BCAA) fall into this category. Branched-chain amino acids seem to offer special benefits when it comes to helping your muscles repair.
A study published in the Journal of Clinical Nutrition showed that branched chain amino acids alter pathways that control protein synthesis and have an anabolic effect. They also have an anti-catabolic effect by preventing the breakdown of lean muscle. This is important if you’re exercising for long periods of time or restricting calories and carbs to try to lose body fat. In these situations, your body is more likely to break down muscle to use as fuel. Branched-chain amino acids help to prevent this. They also may prevent the breakdown of lean muscle tissue during other types of stress. They’re used medically to help burn and victims recover and treat hospitalized patients confined to bed that are a greater risk for muscle atrophy.
Branched Chain Amino Acids and Endurance Exercise
Branched-chain amino acids appear to offer benefits for endurance exercise as well. Based on a study published in the Journal of Sports Medicine and Physical Fitness, BCAAs increase fat breakdown during endurance exercise and increase resistance to fatigue. Another study showed that the response of anabolic hormones like insulin and testosterone were enhanced by branched-chain amino acids more than proteins from whole milk.
Branched chain amino acids have other benefits as well. They preserve lean body mass during weight loss and help to prevent loss of muscle mass with aging.
Sources of BCAAs
Some people take BCAA’s in supplement form. You can also increase the amount of branched chain amino acids in your diet through food. Some of the best sources of branched-chain amino acids are steak, eggs and skim milk. Vegetarian sources include soy milk, lentils, chickpeas, and nuts.
If you choose to take a BRAA supplement, the best time might be before your strength-training workout. It takes between 45 minutes and an hour for blood levels of branched chain amino acids to reach their peak. Supplementing before a workout ensures they’re available to muscle tissue after your workout to help you recover.
The Bottom Line?
It’s important to get enough protein in your diet, especially essential amino acids your body can’t make. Branched-chain amino acids fall into this category and they offer benefits when you strength train and when you do an endurance workout. Make sure you’re getting enough of them through diet before a strength-training workout to help your muscles recover. If you do long periods of endurance exercise, BRAAs may boost your endurance and help prevent the breakdown of lean body mass.
J Sports Med Phys Fitness. 2011 Mar;51(1):82-8.
J. Nutr. January 2006 vol. 136 no. 1 269S-273S.
Amino Acids and Proteins for the Athlete: The Anabolic Edge, Second Edition. CRC Press. (2010)