Muscles have a particularly high content of BCAAs.
BCAAs have also been proposed as a supplement to boost athletic performance. Sources Dietary protein usually provides all the BCAAs you need. However, physical stress and injury can increase your need for BCAAs to repair damage, so supplementation may be helpful. BCAAs are present in all protein-containing foods, but the best sources are red meat and dairy products. Chicken, fish, and eggs are excellent sources as well.