Time under tension - how to use TUT for great results and variety [article]
This article will look at the concept of TUT (time under tension) to explain how to choose the correct number of reps and tempo for your clients. A good understanding of TUT will help you to write better programmes for your clients. It will also help you to clearly explain why you have written your programme the way you have.
What is TUT (time under tension)
How many of us learnt that 4-6 reps builds strength, 8-12 reps is for hypertrophy and 15+ will build endurance. What no one ever told me…and what I never understood…was why?
Understanding TUT made the whole rep number thing make sense to me. See how it works for you.
TUT is the amount of time a muscle is held under tension for during one set of an exercise. Here is an example of how a typical 10 reps might work for a beginner:
Tempo: 2 seconds on the eccentric phase, a 1 second pause at the bottom and 2 seconds on the concentric phase.
You may see this on a programme as 2:1:2, this = 5 seconds per rep.
TUT: 5 seconds x 10 reps = 50 seconds TUT
Often we will see programmes written and they will say Bench Press, 3 sets of 10 reps.
Let’s look at how different the same number of reps could be:
TUT: Tempo 3:1:3 = 7 seconds per rep x 10 reps = 70 seconds
TUT: Tempo 1:0:1 = 2 seconds per rep x 10 reps = 20 seconds
We can see that the same programme could be carried out very differently and as a result have a totally different effect on our client.
How do I know what TUT to use with my clients?
When we look at choosing a TUT for our clients the first step is to decide what the aim of the training is. We need to decide, do we want to build muscle, increase strength, improve endurance. Looking at the energy systems graph below you can see some of the main components of fitness that you may train with your clients. What we are going to do is look at the same exercise and how we can alter the tempo and the TUT to change what effect that exercise will have on our client.
The energy systems and fitness components
Let’s look at an example of power training. Power is the ability to be explosive. Being powerful requires lots of energy very quickly and therefore we use our ATP-PC system. The TUT for Power training would be 5-10 seconds.
TUT: Tempo 2:0:X (explosive) = 3 seconds per rep x 3 reps = 9 seconds
Strength training also demands high levels of energy output. We are lifting the heaviest loads we can so we will need to work at a high intensity for a short period of time. Strength will use both the ATP-PC system and the early part of our anaerobic system. TUT for strength training is in the 10-30 seconds.
TUT: Tempo 2:0:2 = 4 seconds per rep x 5 reps = 20 seconds
Hypertrophy training requires us to work the muscles for longer. We still want to work at a reasonably high intensity, using the anaerobic system. We want to fatigue the muscles and cause muscle damage. This will cause a hormone response (testosterone and growth hormone) that will increase our muscle size. The TUT for hypertrophy training is 30-60 seconds.
TUT: Tempo 3:1:2 = 6 seconds per rep x 8 reps = 48 seconds
Muscle endurance training requires lifting a weight for more than 60 seconds. Therefore the weight can’t be very heavy to begin with (40-60% of their max lifting weight). As the weight is lower, the body doesn’t have to provide energy at such a quick rate. Muscular endurance tends to use the aerobic energy system more (with some anaerobic contribution).
TUT: Tempo 2:1:2 = 5 seconds per rep x 15 reps = 75 seconds
How do I use this with my client?
Now that you understand what TUT is, how do you use it?
First, what are you trying to achieve with this client? Really think about this. Did my 40 year old female client say she wants to ‘tone’? As a Personal Trainer I might decide that for my client to ‘tone’ I want to build some muscle and do a separate cardiovascular programme to help her metabolise fat? Hypertrophy it is! Hypertrophy doesn’t mean I turn my client into Arnie (or Mrs Arnie). Hypertrophy for this client, means rebuilding the muscle she has lost since her 20th birthday.
Now how experienced is my client? New to training? Slow controlled tempo it is. 2:1:2.
Therefore 5 secs/rep x 8-10 reps = 40-50 seconds, putting me nicely in hypertrophy.
What intensity do they want to work at? 6/10
My sets will look pretty standard. Start with 2. After 4 weeks I might progress it to 3. I will set the load so that the intensity for my client will be at a 6/10.
An exercise in my client’s programme now looks like this:
Seated row 2 sets Tempo 2:1:2 Reps: 8-10 Intensity 6/10
The exercise is not complicated for my client to follow, but I can clearly explain why the programme is written the way it is. For me as a trainer, understanding TUT increased my confidence with programme writing. It also gave me more options on how to change a programme. Instead of changing every exercise each month I could keep the client's favourites and change the TUT instead to give them a new challenge.