Trimethylglycine (TMG, betaine) is a dietary supplement and component of beet root, which is a methyl donor. It contributes to metabolic processes in the body which require a methyl group either directly (the methylation of homocysteine) or indirectly via replenishing the active form of folate or via replenishing S-adenosyl methionine (SAMe). As the synthesis of creatine (via GAMT) requires a donation from SAMe, it is thought that TMG can aid in creatine synthesis, which has been noted in the rat liver in the absence of creatine supplementation.
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.