If you know something about muscle function, you realize that taking a couple of supplements together can help create exceptional anabolism—but not by supplying nutrients that build muscle. The compounds in question help you push harder on your work sets, which in turn stimulates the fast-twitch fibers with the most growth potential.
The size principle of muscle fiber recruitment states that the first few reps of a set activate the low-threshold motor units, which brings in slow-twitch fibers and a few fast-twitch. As the reps get harder, toward the middle of the set, the medium-threshold motor units fire, which activates more fast-twitch fibers. The last few hard reps of a set, however, are what trigger the high-threshold motor units, finally bringing in the fast-twitch fibers that are most responsible for muscle growth.
What that means is, if you can more readily push through the pain zone, you’ll stimulate more growth by getting at more of those key fast-twitch fibers. You can do that with two supplements. The first is creatine, which helps you regenerate ATP in the muscle. It’s a power-oriented supplement that enhances muscle energetics, and it’s perfect for helping you grind out more reps on lower-rep sets.
The other supplement is beta-alanine, which converts to carnosine in muscle tissue. Carnosine buffers the burn during higher-rep sets, as well as on end-of-set forced reps and X-Rep partials. Studies show that the biggest bodybuilders have more than twice the carnosine of untrained individuals, no doubt an adaptation from intense workouts performed in the pain zone. New studies show that beta-alanine synergizes with creatine, making size and strength gains even more pronounced—a muscle-building smart bomb! (Med Sci Sports Exerc. 38:S126; 2006)