Wall Street Journal Best Seller. Improve your physique, build lean muscle, and increase strength.For more than twenty years, Bret “the Glute Guy” Contreras has been on a quest to improve human performance, focusing his research on the gluteus maximus, the largest muscle in the human body. What started as an effort to improve his own weak, flat backside quickly evolved when he discovered the wide range of functional movements to which the glutes contribute. Properly trained glutes not only help you lift heavier, jump higher, sprint faster, and swing harder but also help prevent knee, hip, and lower back pain and injuries. Bret went on to earn a doctorate in sports science and is now known as one of the world’s foremost experts on strength and physique training.