Why it made the list: Whey tops the list of mass-gain supplements because it's the most crucial for pushing protein synthesis. Whey is a milk protein that has a high level of branched-chain amino acids (BCAAs, No. 4 on our list). Bottom line: Whey takes the crown because it digests fast and gets to your muscles rapidly to start building muscle. Whey also contains peptides (small proteins) that increase blood flow to the muscles. This is why we always recommend consuming whey protein immediately after training.
Using too much weight, too soon; always start lower than your expected ability and work your way up that first workout. If your form suffers, you are swinging the weight, or using momentum, this indicates you may be using too much weight. Greater momentum increases the potential for injury and reduces the effectiveness to the muscle group being targeted.