This is the first 12-week study using the new delivery form of beta-hydroxy-beta-methylbutyrate, HMB free acid. Highly trained athletes underwent an intense, high-volume, resistance-training program, including a 2-week overreaching phase during weeks 9 and 10. HMB free acid supplemented subjects had greater strength gains, increased Wingate power, and increased muscle thickness compared with the placebo-supplemented subjects. This study showed that even in highly trained athletes, HMB free acid results in greater training gains over a 12-week periodized resistance-training program.