NEW: “Effects of 4, 8, and 12 Repetition Maximum Resistance Training Protocols on Muscle Volume and Strength.”

Kubo, Keitaro; Ikebukuro, Toshihiro; Yata, Hideaki,_8,_and_12_Repetition_Maximum.1.aspx


To determine skeletal muscle adaptations (strength and hypertrophy) in response to volume-equated resistance training with divergent repetition strategies.

10 weeks at 2 training sessions per week:

Group 1: high load @ 7 sets x 4 reps.

Group 2: intermediate load @ 4 sets x 8 reps.

Group 3: Low load @ 3 sets x 12 reps.

Group 4: Non-exercising control group.


The increase in muscle size was similar among the 3 training protocols when the training volume was equated, whereas the increase in muscle strength was lower with the 3 x 12 protocol compared to the other two.


A lot of protocols work for increasing muscle size (7 x 4, 4 x 8, and 3 x 12), while the 3 x 12 did not increase muscle strength as much as the other two. To demonstrate pure strength, heavier resistance that recruits a larger quantity of muscle fibers allows for that, thus the 7 x 4 and 4 x 8 were effective. The 3 x 12  required a lighter resistances thus the recruitment of fewer fibers occurred and did not result in optimal strength increase.