Time Under Tension: Control the Rep, Then Track the Work

Sep 26, 2023

2 min read

Updated: 23 hours ago

Time under tension describes how long a muscle is working during a repetition or set. It can help describe execution, but a longer set is not automatically a better muscle-building set.

Change one thing at a time

Consider a set of controlled curls. Slowing the lowering phase, changing the load, shortening the range or adding repetitions can all change the experience. Those are different adjustments. If they change together, it becomes harder to tell what improved.

Record a simple tempo cue when it matters, such as a controlled lowering phase and a deliberate lift. You do not need a stopwatch for every repetition. Choose a pace that lets you perform the intended movement and recognise when control deteriorates.

Tension is not confined to the final repetitions

Earlier repetitions still involve force production. The claim that genuine tension appears only at the end of a set is too simple. Likewise, a cyclist's legs do not prove a particular lifting tempo is optimal.

Schoenfeld and colleagues' repetition-duration review found hypertrophy across a range of durations; it does not establish one universal slow-repetition prescription. Exercise, load, effort and the wider programme still need consideration.

A coaching example

Keep the exercise and repetition target consistent for several sessions. If repetitions become rushed or the intended range disappears, adjust the load or end the set. Progress when you can do more comparable work, rather than manufacturing a longer set through an arbitrary count.

Use tempo to make the exercise clearer. Do not let a time-under-tension target obscure what the session is meant to achieve.