Certain amino acids (protein building blocks) called branched-chain amino acids can also mitigate fatigue (Greer 2011). They work by blocking the absorption of tryptophan, one of the main chemicals that causes the brain to sense fatigue (and briefly acknowledged every Thanksgiving). These amino acids include leucine, isoleucine, and valine and can be supplemented at 1,200–3,000 mg per day, in divided doses, between meals. This kind of amino acid also reduces muscle damage during exercise, so can relieve fibromyalgia muscles that are working hard even while at rest (Greer 2007).
