Your body adapts to the type of training you do. This is called the SAID principle, which is short for Specific Adaptations to Imposed Demands. In simple terms, SAID means you are fit for what you do.
So, to be a better runner, you need to head out and do plenty of running. Conversely, to get stronger, you must perform workouts that tax your strength, such as lifting heavy weights.
However, it’s not enough to train specifically for your goals; your workouts also need to be progressive, meaning they gradually become harder over time. Doing the same workout over and over is a good way to maintain your current fitness or strength, but it won’t move you forward.
To continue progressing and avoid training ruts and plateaus, you must learn how to manipulate the so-called training variables. These are the modifiable elements of your workouts. Adjusting these variables means you can gradually turn up the intensity of your workouts to continue making progress.
The main training variables for strength and muscle building are:
- Training frequency
- Reps per set
- Number of sets per exercise
- Number of exercises per muscle group
- Length of rest between sets
- Choice of workout equipment
- Choice of training split
- Choice of exercises
Using these variables, you can create an infinite number of workouts and training programs to maintain your progress.
There is another variable you can manipulate – time under tension, or TUT for short. In this guide, we reveal what TUT is, how to use it, and reasons for and against TUT-based training.
What is Time Under Tension?
Time under tension (TUT) is the time your muscles are working during a set. TUT is intrinsically linked to your training tempo, which is the speed at which you perform your reps.
For example, if you do ten reps and take two seconds to raise the weight and two seconds to lower it, each rep will take four seconds, giving you a TUT of 40 seconds. So, providing you do the same number of reps, if you speed up, your TUT will be less, and if you move more slowly, your TUT will increase.
Some fitness experts believe there is an optimal TUT to achieve specific training goals. For example, 40-60 seconds per set is often considered best for muscle growth, while 10-15 seconds is better for building strength.
Because of this, many training programs prescribe tempos to achieve the “ideal” TUT.
For example, you may see tempo prescriptions that involve lifting a weight in two seconds and lowering it in four. Some may also include pauses to further control tempo and TUT.
2:1:4:1 would mean lift in two seconds, pause for one second, lower in four seconds, pause for one second. This gives a TUT of eight seconds per rep or 48 to 64 seconds for a set of six to eight.
So, by adjusting tempo and rep count, it should be possible to hit roughly the same TUT for all of your work sets.
While all that math makes a certain amount of sense, and TUT can be a useful training variable, there is little evidence to suggest that hitting a particular set duration is the key to making gains.
Is Time Under Tension Effective?
Despite having a lot of fans, there is very little evidence to suggest that TUT is critical for optimizing muscle growth. In fact, several studies have found that TUT is unimportant, and manipulating it does not affect the outcome of a workout.
In one study, participants were divided into two cohorts. One group trained with a TUT of 30-48 seconds per set, and the other group used a TUT of 90-120 per set.
TUT theory states that the first group should have experienced better muscle growth because their sets fell within the 30 to 60-second hypertrophy “sweet spot.” However, in actuality, both groups saw similar muscle growth despite the vastly different TUTs (1).
In another study, exercisers with several years of strength training experience were allocated workouts with a TUT of 30-40 seconds or 9-12 seconds. While the short TUT group experienced more significant strength gains, both cohorts experienced similar increases in muscle mass (2).
A third study divided experienced lifters into two groups, with one doing four sets of 10-12 reps and a TUT of 50-60 seconds and the other doing four sets of 3-5 reps and a TUT of 15-30 seconds. As with the other studies, there was no real difference in muscle gains (3).
In summary, research indicates that TUTs ranging from as short as 15-20 seconds or as long as 60-90 seconds can produce muscle gains. That’s good news if you find tempo prescriptions difficult to understand or controlling your rep speed distracting.
But before you turn your back on TUTs and training tempos forever, it’s worth noting that controlling your rep speed and set duration can be useful in certain circumstances.
How to Use TUT for Safer, More Effective Workouts
Just because there is no magic TUT that guarantees maximal muscle growth doesn’t mean that regulating your rep speed is a waste of time. There are several situations when using a controlled tempo, and a more prescriptive TUT could be beneficial:
Getting a more intense workout from lighter weights
Training with a slower tempo makes light loads feel heavier. For example, ten slow push-ups are much more challenging than ten fast reps. The longer your muscles are under tension, the harder your set will be.
You can use a longer TUT to make bodyweight exercises more demanding or when you only have access to light weights, e.g., at a hotel gym with limited equipment.
Training when injured
Heavy lifting can take its toll on your body, and injuries are not uncommon. While it’s often best to rest and allow healing to occur, this is sometimes easier said than done. Many exercisers prefer to train around or through their aches and pains.
Using a slow tempo means you can reduce your training weights and still get a decent workout. For example, instead of doing bench presses with 100kg/220lbs, you could drop the weight to 60kg/110lbs and use a much slower tempo and longer TUT.
This will put far less stress on your joints and connective tissue. However, you’ll still be able to create the metabolic demands necessary for muscle growth. At the very least, your workout will be stimulating enough to maintain your gains while giving your body the break it needs to heal and recover.
As mentioned at the beginning of this article, your workouts must be progressive for you to keep building muscle and getting stronger. If you don’t make your workouts harder, your gains will stall.
While you could do more reps per set, more sets, or lift heavier weights, you can also use time under tension to make your workouts more challenging.
For example, over four weeks, you could use the following progressions:
- Week 1 – 25-35 seconds TUT (e.g., 2:2 tempo for 6-8 reps)
- Week 2 – 35-50 seconds TUT (e.g., 3:3 tempo for 6-8 reps)
- Week 3 – 50-65 seconds TUT (e.g., 4:4 tempo for 6-8 reps)
- Week 4 – 25-35 seconds TUT (increase the weight 5-10%)
Better form and increased mind-muscle control
There are two ways to perform any exercise – the right way and the wrong way. The right way keeps the tension on the target muscles and is generally safer and more effective. The wrong way often lets you lift heavier weights or do more reps but also puts stress on other parts of your body and could even lead to injury.
Moving slowly and deliberately forces you to pay more attention to your form. It eliminates momentum and usually means you are less likely to try and cheat the weight up. For example, if you lower the barbell under control during bench presses, you won’t be tempted to try and bounce it off your chest.
This slower tempo will also help strengthen your mind-muscle connection. The more you can control and feel a muscle working, the better your workout results will be. If you can’t feel the target muscles during an exercise, it probably won’t produce the results you want.
For the challenge!
While TUT doesn’t play much of a role in strength and muscle gains, that doesn’t mean you should dismiss controlled tempos entirely.
This challenge could help you build strength and muscle size despite taking less than three minutes. Do it whenever you are short on training time but still want to hammer your upper body.
Target muscles: Latissimus dorsi, trapezius, rhomboids, biceps, forearms.
Start by hanging from your pull-up bar with an underhand, slightly narrower than shoulder-width grip. Bend your arms and take 30 seconds to pull your chin up and over the bar. No locking off is permitted; just keep moving very slowly.
Next, take another 30 seconds to slowly lower yourself back down. Again, no locking off at any point. Descend smoothly to full arm extension.
Rest for one minute, and then do the second exercise…
Target muscles: Pectoralis major, deltoids, triceps.
Begin your dip at the bottom with your arms fully bent. This is important because you are stronger eccentrically than you are concentrically. This means you can lower more weight than you can lift. You may not be able to complete this challenge if you start your dip at the top.
As with the chin-up, take 30 seconds to push yourself up and another 30 seconds to descend. Do not lock out at the top or stop at any point. Keep moving, albeit very slowly.
Congratulations – you have trained every major upper body muscle in three minutes!
Time Under Tension (TUT) Explained -Closing Thoughts
There is nothing wrong with using a prescriptive time under tension or tempo. If you enjoy that sort of training, there is no reason to stop doing it.
However, there is also nothing magical about hitting a specific TUT. Just because your set lasts 40-60 seconds does not mean it’ll be effective.
Instead, taking your sets to within 2-3 reps of failure is more important. The muscle tension this produces is much more important for hypertrophy than your TUT. Ultimately, you can build muscle from sets of 5 reps or 35, providing you get close enough to failure (4).
So, file TUT under useful but not critical to your strength and muscle building success!
- PubMed: Resistance Exercise Load Does Not Determine Training-Mediated Hypertrophic Gains in Young Men https://pubmed.ncbi.nlm.nih.gov/22518835/
- PubMed: Effects of Different Volume-Equated Resistance Training Loading Strategies on Muscular Adaptations in Well-Trained Men https://pubmed.ncbi.nlm.nih.gov/24714538/
- PubMed: The Effect of Training Volume and Intensity on Improvements in Muscular Strength and Size in Resistance-Trained Men https://pubmed.ncbi.nlm.nih.gov/26272733/
- PubMed: Effects of Resistance Training Performed to Repetition Failure or Non-Failure on Muscular Strength and Hypertrophy: A Systematic Review and Meta-Analysis