Equalization of Training Protocols by Time Under Tension Determines the Magnitude of Changes in Strength and Muscular Hypertrophy

Muscle growth occurs primarily when mechanical tension is applied over a sustained period of time.

In untrained men doing bench press training for 10 weeks with consistent time under tension, the distal part of the triceps brachii muscle grows more than its proximal and middle parts, while the pectoralis major muscle grows evenly along its entire length.

Untrained men who perform resistance training at moderate weights with controlled movement speed for 10 weeks experience significant increases in muscle size and strength, and nearly all of them show measurable improvements.

In untrained men, performing bench press exercises with the same total time under tension (36 seconds per set) leads to the same increase in maximum strength and muscle size of the chest and triceps after 10 weeks, whether each repetition takes 3 seconds or 6 seconds.

In untrained men who perform bench press training for 10 weeks with equal total training time, the lower part of the triceps muscle grows larger in cross-sectional area than the middle and upper parts.

For men new to weight training, counting how many times they lift a weight does not fully capture how much work they did; matching the total time the muscle is under tension produces the same adaptations.