In the pantheon of supplements, protein reigns supreme. But taking protein doesn’t fulfill all the amino requirements of a gym-going body. And if you have to choose one amino acid to supplement with, in addition to your daily protein shakes, choose leucine. Leucine, along with its fellow branched-chain amino acids, is processed differently by the body than other amino acids, but that’s only one of its benefits:
Leucine increases the body’s use of stored fat.
Leucine revs up metabolic rate, requiring the body to burn more calories, which the body supports by pulling fat from storage. Bonus: If the body is burning body fat, it’s sparing muscle tissue. The most crucial time to take leucine for this benefit is before workouts.
Leucine encourages protein synthesis.
In addition to sparing muscle tissue, leucine promotes muscle building by increasing protein synthesis, the process by which muscle cells grow. This increase allows muscles to build tissue more readily, increasing lean mass. The most important time to take leucine for this benefit is after workouts.
Leucine boosts insulin release.
Around workouts, an increase in insulin is a good thing; it drives nutrients to muscles to help fuel workouts and repair muscle tissue stressed by training. At other times of the day, insulin release is not so good because it tends to encourage body-fat storage. Because leucine is digested quickly, it spurs the release of insulin, making it an ideal preworkout and postworkout supplement.
Take leucine either alone or as a BCAA supplement that provides leucine in a ratio of 2:1:1 to isoleucine and valine. For best results, take 3 to 5 grams of BCAAs or 2 to 3 grams of leucine before and after workouts. You also can add another dose of leucine or BCAAs first thing in the morning and with any meal that contains fewer than 30 grams of protein.