Today Robert and Trent discuss why you need to train for strength, and why your lifts MUST be heavy to build muscle mass. It's popular these days to train for "hypertrophy" utilizing sets of 10-12 reps on a large variety of exercises, many of them single joint lifts. The problem with this approach is that, for the vast majority of people, they do not do these exercises heavy enough to drive muscle growth, and they lack the strength to do them heavy enough to see results anyway.