Determining the optimal Time Under Tension (TUT) for a set or repetition is a topic that warrants careful consideration. To get to the heart of this matter, it’s crucial to explore the Effective Reps Theory, which sheds light on the question of TUT.
TUT, in its essence, measures the duration of a set in seconds, calculated by considering both the eccentric (lowering) and concentric (lifting) phases of a rep. For example, if you execute 10 reps with a 3-second eccentric and a 1-second concentric, your TUT for the set would roughly total 40 seconds. This metric may seem logical from an energy systems perspective, but when it comes to hypertrophy, it doesn’t necessarily align.
Hypertrophy is primarily driven by muscle tension, and this is where the Effective Reps Theory comes into play. Effective reps are the ones that recruit the fast-twitch muscle fibers, which are prone to growth. Achieving effective reps demands a high level of effort and, consequently, a significant amount of tension in these fibers. While slower reps indeed generate more tension, this doesn’t imply intentionally slowing your repetitions. Instead, it suggests that as you push hard during a set, your reps may naturally slow down due to fatigue.
Typically, the last 4-6 reps of a set are the ones that qualify as effective reps, regardless of the total number of reps performed. Thus, Time Under Tension doesn’t significantly impact this outcome. Prolonging TUT by adding non-effective reps does not contribute to muscle growth. However, there is some value in extending the eccentric phase (the negative part of a rep), but this benefit has its limits.
In practical programming, many experts, including the author, do not prioritize TUT as a primary consideration. Instead, the focus often lies in training to failure or just shy of it, with the understanding that the last few reps of a set are the true drivers of hypertrophy. So, if you’re pondering the role of TUT in your workout routine, consider it in the context of effective reps and their influence on muscle growth, as this perspective can guide your training more effectively.