Is it true that you only need 15 seconds of intense exercise to retain muscle?!

Is it true that you only need 15 seconds of intense exercise to retain muscle?

I read in an article that when you're cutting, you only need to engage your muscles for 15 seconds to prove to your body that you need that muscle.

So, that chould be as simple as flexing heavily for 15 seconds, right? Or lifting a heavy weight and holding it half way for 15 seconds, right?

Is that true or was it fake and should I just work out those muscles heavly with small reps? Like the 5x5 workout or the 3x3 workout?

Hi Hank,
A time under tension of 15 seconds would equate to about 5 reps. This would be like lifting an extremely heavy weight for low reps. Although I have not had the chance to see any lab data on the subject, I suspect that there might be some truth to the assertion.

However, if you are going to train each muscle group like this, I would recommend a thorough warmup and using very strict form to avoid injuries.