Trying to go all out in your training efforts, but instead you’re feeling beat into the ground? Consider adding cystine, part of the cysteine family, and theanine, precursor to glutamate, to your supplementation regimen. These two substances help your body create glutathione, which modulates natural killer-cell activity — they’re the Pac-Man-like cells that chomp up disease.
Japanese researchers report in the March 2010 issue of the Journal of Strength and Conditioning Research that athletes who participated in high-intensity exercise at a high frequency and supplemented with 700 milligrams of cystine and 280 milligrams of theanine daily for two weeks didn’t experience a decrease in immune-cell activity or an increase in other inflammatory markers. Just think: You can train harder longer without getting sidelined by sickness. Now, which way to the power rack?