After performing all the full reps in strict form, you can still Tax your muscles for several partial reps. Returning to our barbell curl example, after reaching failure at 8-10 reps and still keeping perfect form intact, curl the weight up as far as you can. Perhaps you’ll be able to curl it only halfway. That’s fine. Your muscles are still working; that’s the important thing. The next time, you may not even be able to make it halfway. For the next couple of reps, you may be able to complete only a quarter of the range of the movement. You’ll quickly reach a point where you can move the barbell only a few inches from your thighs, and yet you should be able to do this short movement numerous times perhaps five or six.
These short reps at the end of a set are called burns, and they’re appropriately titled. As you move far beyond failure, burns will indeed create a smoldering sensation in your muscles, a sure sign that you’ve fully taxed the targeted area. Burns can also be performed after the other set-expansion techniques to truly push a set far beyond its normal limits.
BUT YOU MUST RELAX THE MUSCLES AFTER EVERY REP.