Multiple Sets Are the Clear Winner if the Goal is Gaining Strength, Endurance, and Muscle Growth
A 2009 study found that two to three sets per exercise were associated with a 46% greater strength gain than one set in both trained and untrained subjects. A 2010 study showed a similar gain in muscle growth in trained and untrained subjects who completed multiple sets. Finally, a 2015 study looked at one, three, and five sets of exercises. Study authors found that multiple sets were better with regard to strength gain, muscle endurance, and upper arm muscle growth.