What Is Time Under Tension?
What Is The Duration Or Time Under Tension
Of The Fast Twitch Vs. Slow Twitch Muscle Fibers?
In this video I want to explain to you a very important concept regarding “time under tension” in your muscle fibers.
I can usually tell when someone in the gym has done some serious research about gaining muscle when they start asking me about time under tension.
Now that you already know how your rep range correlates with the intensity percentages, I’m going to give you another piece of the “muscle gain” puzzle that’s going to really supercharge your training, and that piece of the puzzle deals with the “time” that your muscles are under “constant” tension.
What is time under tension you may ask? Well…
I discovered when I was doing the experimental research on the prisoners that a person can only use (contract) their fast twitch muscle fibers for roughly 30 to 60 seconds.
This is very important… because if you try to do the low rep ranges and the high percentages for more than 60 seconds, it’s very, very difficult.
As a matter of fact, among the hundreds of prisoners I have trained over a decade period, I did not see one prisoner that was able to activate the fast twitch muscle fibers and maintain the “time under tension” correctly for more than 60 seconds.
So if you want to go out there and test the idea of time under tension, for yourself, you’re welcome to, but I’ve already done the research for you, so I don’t recommend you waste your time.
The 30-60 second rule is very accurate at 10 reps or less.
Around 16-18 reps there could be some variances with your time under tension, but it’s extremely accurate whenever you start to train between 75-100% of your 1RM.
What Is The Duration Or Time Under Tension
Of The Slow Twitch (Endurance) Muscle Fibers?
I also discovered that you can train for one minute to an unlimited amount of time when you train below 60% of your 1RM.
When I say “unlimited”, I mean that your duration of time under tension is only hindered by your mental capacity.
It depends upon the “mental psychology” and how mentally tough that you are as an athlete and you can actually sit there and just run on the treadmill, or run around the track for as long as you want to and the only thing that would prevent you from doing so is your mental capacity.
Now keep in mind, you’re not going to be running for, like, 20 or 40 hours, okay.
But when I say that the slow twitch (endurance) fibers have an “unlimited” time under tension, I mean to say that it can work for a very long length of time, it’s definitely longer than a minute for sure.
If you notice, most marathon runners use and train mainly the slow twitch (endurance) muscle fibers and that is why they can run for several hours without any problems.
The next time you are at the gym, pay very careful attention about the time under tension of their exercise, especially when you see someone do an exercise such as a set of bench press, shoulder press or curls for more than 60 seconds you will know immediately that they are NOT training their fast (strength/speed) twitch fibers. Why?
Because the fast twitch (strength/speed) fibers do not last more than 60 seconds.
None of the fast twitch fibers can contract for more than 60 seconds because their time under tension is very short because they use a special type of fuel that are inside the muscle cells. I will cover that special type of fuel in the next section.
If you are training to build speed, strength, and size in your muscles, and you train for longer than 60 seconds per set, then you’re really wasting your time because you’re only training the slow twitch fibers or the endurance muscles.
How To Train Using “Time Under Tension”
Instead Of Using Rep Ranges
If you don’t want to use the reps, you can also use the “duration” or “time under tension” of your muscles to train yourself depending upon if you’re trying to lose body fat or gain muscular size and strength.
- If you are training to lose body fat, then you want obviously train for longer than 60 seconds.
- If you’re training for strength, speed, or size, then you want to train for less than 60 seconds.
On average, when it comes to strength training, I usually recommend training around 30-40 seconds per set. I don’t even like to waste time and wait until the set lasts for 60 seconds.
The only exception to training for longer than 60 seconds on each set is when you are completely out of shape and unconditioned or when you are training very heavy and require more mental concentration and re-focus in between each set.
You should be able to complete a set of 10 reps in less then 40-60 seconds.
Even with the really tough exercises such as the squats and the deadlifts, you should still be able to do 10 reps under 40-60 seconds UNLESS you haven’t been training for a while and NOT very conditioned.
If you are not very well conditioned, it will take you more than 60 seconds to do the 10 reps.
If you happen to take more than 60 seconds to complete one set of 10 reps when you first start working out, you are not violating the laws of muscle gain “physics”.
It’s probably because you are NOT very well conditioned, so your body takes longer to get rid of the lactic acid and the waste product that the fast twitch (strength/speed) muscle fibers are producing and that’s the reason why it’s taking you longer than 60 seconds.
For the average person that’s been working out for a while, you are not going to be able to last longer than 60 seconds when using your fast twitch (strength/speed) muscle fibers.
So keep that in mind as you are training, if your are training to build muscle strength, size or speed, you’re probably not getting the best results possible if you are “well conditioned” and each of your workout sets last longer than 60 seconds of time under tension.
Thanks for checking out this video and article regarding time under tension, and in the next section I’m going to explain to you:
- The difference in aerobic and anaerobic exercises
- The 2 different fuel systems in your body.
- The fuel type that the strength/speed fibers use.
- The fuel type that the endurance fibers use.
- How to refuel properly for muscle and strength gains.
So keep an eye out for my next exciting email!