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What does Time Under Tension mean?

Time under tension (TUT) refers to the time spent contracting the muscle. It is often touted in bodybuilding as the key to hypertrophy.

TUT is an important rule of thumb for r muscle growth, but it is not the only rule. The training goal should be to implement efficient and intentional Time Under Tension into your routine with appropriate tempo, reps, and varying ranges of motion that fit into your specific hypertrophy goals.


The overarching goal of TUT weightlifting is to maximize the efficiency of output in a given length of time. By being efficient with the time we have in a set, we make proper use out of TUT. If you have ever worked with a personal trainer, you have probably heard about TUT. This is best accomplished through a slow tempo. One of the hallmarks of TUT training is a “controlled negative,” or a slow and controlled release on the eccentric phase of the lift.

In other words, don’t let the weight fall down fast.

For example, a slow bench press with a partial range of motion, keeping the barbell above your chest without touching it, is a TUT version of this exercise. With TUT training, there is no rest in between repetitions. The tension should be felt throughout the entire set. To maximize the time spent under tension, make sure you keep the tension on the desired muscle groups throughout the entirety of the lift.

The eccentric and concentric phases of the lift should be equally strenuous.

Don’t let gravity help you bring the weight down. You want to maintain your desired average tension on both parts of the lift. Before focusing in on a specific length of TUT, practice slowing down your lifts and maintaining tension throughout the set. Then, give yourself a specific time, and see how many slow reps you can do. Find out what you can comfortably lift, slowly, for 8-15 reps. The goal is not to get more reps into a set amount of time, but rather, to spend more time under tension throughout the entirety of the set.


So what is the optimal TUT for muscle growth? The answer is, it depends.

Research shows that greater time spent under tension results in, “A robust, but delayed stimulation of myofibrillar protein synthesis 24-30 h after resistance exercise.” In other words, it helps you build muscle mass by facilitating muscle protein synthesis.

For muscle hypertrophy or growing muscle size, the optimal time under tension is 40-70 seconds.

The amount of time spent on each set will be dictated by the load and your strength level. Go lighter for more time, and heavier for less time. It is a large time frame because the ideal TUT for a set is heavily dependent on the training volume. If you are lifting below 75% of your max, then your optimal set length will be closer to 60-70 seconds.

If you’re lifting heavy, above 75% of your max, then 40-50 seconds may suffice.

Sets that include 60 seconds of complete time under tension are appropriate for muscle growth. With a total tempo of 5 seconds, you can get 12 repetitions into a 60-second set. For hypertrophy, anywhere between 4-8 sets, depending on your goals and training style is appropriate while incorporating TUT training for muscle growth into your routine.


When you start implementing TUT training into you’re routine, you will have to start paying attention to tempo. Tempo refers to the amount of time it takes to complete the rep. Tempo accounts for the time it takes to complete both the eccentric and concentric parts of the movement. Slowing down the eccentric part of the lift is how you increase TUT.

The eccentric part of the lift the coming down, or back to starting position.

In the example of a bicep dumbbell curl with a tempo of 2-0-3-0, you take 2 seconds to bring the dumbbell up to your biceps (concentric movement), pause for zero seconds (meaning don’t pause at all), and take 3 seconds to bring it down to the starting position. To do this, you have to resist gravity as you bring the weight down. For TUT training, keep the pauses between reps at 0 seconds. In this example, a tempo of 5 seconds total per rep, 2-0-3-0, a set of 12 seated concentric bicep curls will be accomplished in 60 total seconds of TUT.


Time under tension training doesn’t have to limit your range of motion (ROM). You should be able to accomplish repetitions of both partial and full ranges of motion without sacrificing your time spent under tension. TUT training does not dictate a range of motion, and it is best to incorporate a variety of ranges of motion into your program. If, however, a full range of motion on a particular exercise causes you to pause at the bottom or top of your lift, thus breaking up the time under tension, then you may need to consider either limiting the range of motion on the movement to maintain the TUT.



Cables are a great way to control the eccentric movement, or decent, of your reps. Cables control your range of motion, allowing you to isolate your muscles better while controlling your tempo. On a cable bicep curl, for example, as long as you have enough distance between the weights and yourself, the tension on the cable remains constant throughout the entire movement, even when you come all the way back to the starting position. This makes cables a valuable tool for increasing the time that your muscle fibers spend under tension.


A selective range of motion can be a valuable tool for increasing TUT. Stopping midway through the eccentric movement of a lift causes you to work against gravity. To ensure constant tension throughout your set, try not to go all the way down.


Slowing down your repetitions and using lighter weights is the easiest way to immediately increase TUT during your lift. Do not let gravity help you on the way down, and don’t let momentum assist you on the way up. Slow controlled movements, about 5 seconds per rep, are ideal.


Watching your tempo is key if you want to build muscle and strength. Pauses at the top of a lift are acceptable and will contribute to the time spent under tension. Pausing at the bottom of the lift, however, will abruptly interrupt your time spent under tension. A tempo of 2-0-2-1 on a bicep curl, for example, is a TUT-focused strength training tempo.


Increasing the amount of time spent under tension is a muscle-building hack amongst bodybuilding enthusiasts. If hypertrophy is the goal, you should incorporate tut into your resistance training routine. Slowing down your lifts, extending the length of time of your sets, and adjusting your range of motion will result in increased activation of muscle fibers.

Due to the low weight/high rep nature of TUT, adopting this training style may cause you to spend more time at the gym. Time under tension is a valuable muscle-building tool, but it is not the rule, but rather, a rule of thumb to always consider in your training.


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