Tempo and Time Under Tension
Controlling the lowering phase is worth doing. Time under tension as a number to chase is not, and the difference matters more than the debate suggests.
Last updated: 1 July 2026
Overview
Tempo is how fast each phase of a rep is performed. Time under tension is how long a set keeps the muscle loaded.
The first is a useful tool. The second is a real thing that became a target, and targets made of side effects tend to mislead.
Quick Answer
Lifting tempo is written as four numbers: the lowering phase, the pause at the bottom, the lifting phase, and the pause at the top. Controlling the lowering phase over roughly two seconds is worthwhile. Deliberately slowing reps to accumulate time under tension reduces the load you can use and offers no clear advantage.
Key Points
- Tempo notation is four numbers, and the first is the lowering phase.
- Control the lowering. Two seconds is plenty.
- Lift the weight with intent, even when it moves slowly.
- Chasing time under tension costs load.
- Very slow reps are a tool for learning, not a growth method.
Reading the notation
A tempo of 3-1-1-0 means:
| Position | Phase | In a squat |
|---|---|---|
| 1st | Eccentric, the lowering | 3 seconds down |
| 2nd | Pause at the bottom | 1 second |
| 3rd | Concentric, the lifting | 1 second up |
| 4th | Pause at the top | 0 seconds |
An X in the third position means explosive: move the weight as fast as you can, even if it is heavy enough that fast is not very fast.
What is worth doing
Control the lowering. Around two seconds. Not because a number matters, but because dropping the weight removes the eccentric portion of the rep, which is a meaningful part of the stimulus and the part most associated with muscle damage and adaptation.
Lift with intent. Trying to move the bar quickly recruits more motor units, whether or not it actually moves quickly. On a heavy set it will not look fast; the intent still counts.
Pause where the position is hard. A pause at the bottom of a squat or on the chest in a bench press removes the bounce and exposes whether you actually own the position.
What is not worth chasing
Time under tension as a number.
The problem is straightforward: to accumulate more seconds you have to use less weight. Doing a set of ten at a four second lowering means dropping the load, and you have traded mechanical tension, which is the primary driver of growth, for a stopwatch reading.
| Approach | Load | Likely outcome |
|---|---|---|
| 10 reps, 2 sec lowering | Heavier | Good |
| 10 reps, 5 sec lowering | Noticeably lighter | Not better |
| 10 reps, dropped weight | Heaviest | Worse, eccentric missing |
The middle row is where most time-under-tension programming lands, and it is the one with no clear advantage.
Where slow really does help
- -Learning a movement. Slow reps at light weight are an excellent way to feel a position.
- -Home training. When you cannot add weight, slowing the lowering is one of the few ways left to make an exercise harder. See [the bodyweight routine](/wiki/articles/bodyweight-routine).
- -Connecting with a muscle. If you genuinely cannot feel a muscle working, slowing down often helps more than any cue.
- -Rehabilitation contexts, under guidance from whoever is running it.
The soreness trap
Slow eccentrics produce a lot of soreness, and soreness gets mistaken for effectiveness. It is not, as [muscle soreness explained](/wiki/articles/muscle-soreness-explained) covers: it reflects novelty, not stimulus.
Feeling wrecked after your first session of five second negatives tells you the session was unfamiliar, not that it was better.
Common Mistakes
| Mistake | Why it causes problems | Better approach |
|---|---|---|
| Chasing seconds under tension | Forces lighter loads | Control the lowering, keep the weight |
| Dropping the weight on the way down | Discards half the rep | Roughly 2 seconds down |
| Slow on the way up on purpose | Reduces motor unit recruitment | Lift with intent |
| Tempo prescriptions on every exercise | Complexity without payoff | Control the eccentric and move on |
| Judging it by soreness | Soreness measures novelty | Judge by the log |
Frequently Asked Questions
How fast should I lift?
Lower under control over about two seconds, and lift with the intent to move the weight quickly, however fast it actually travels.
Does time under tension build muscle?
Longer sets involve more time under tension, but deliberately slowing reps to increase it means using less weight, which offsets the benefit. Mechanical tension matters more than duration.
Are slow negatives worth doing?
As a tool, yes: for learning movements, for training without heavier weights, and for feeling a muscle. As a default method, no.
What does 3-1-1-0 mean?
Three seconds lowering, one second pause at the bottom, one second lifting, no pause at the top.
Sources
National Strength and Conditioning Association - https://www.nsca.com/
American College of Sports Medicine - https://acsm.org/