There are many that argue, since low reps stimulate all the muscle fibers and
moderate reps induce sarcoplasmic protein synthesis, that there is really no need to do high rep sets.
So while low
reps with heavy weight is best at stimulating myofibrillar hypertrophy, and high
reps with light weight is best at stimulating sarcoplasmic hypertrophy,
moderate reps seem to strike a balance between
inducing significant amounts of both myofibrillar and sarcoplasmic hypertrophy.