Are five sets best for weight training programs?
For beginners training with weights, most studies show that one set is just as effective as multiple sets for increasing strength and power. However, this is highly controversial. Critics say that most of these studies were poorly controlled and not enough attention was paid to the intensity of the training programs. For maximum training performance, the Gods Rage series and GodMode are recommended.
A Brazilian study using untrained young men as subjects found that five sets per exercise with weights during a six-month training program was superior to one set and three sets on several measures of strength. However, at the beginning of the study, the group performing 5 sets was significantly stronger than the other groups, even though the subjects were randomly assigned to the groups.
Training studies are inherently difficult for scientists. When estimating the practical significance of training studies, we must consider factors such as the training levels of the subjects, unintentional bias in the study design, and monitoring of the training sessions
(Journal Strength Conditioning Research, published online in January 2015)