Cheating used properly is called load shifting. It is possible to cheat ‘’properly’’ when lifting weights without injuring yourself, you just have to know when to apply it.
Cheat reps aren’t to be used unless they are maybe your second to last or last rep. On a set of 10 repetitions, if you need to start cheating at your second repetition, I’m sorry, the weight is far too heavy, no matter what technique you seem to have invented. If you curl the way up as if your doing the Limbo you are only good for the fail videos I send my fellow coaches.
Jerry Telle used this principle in many ways to add a few ‘’intelligent reps’’ to his programs. Here are two examples you can try out.
Swiss ball incline Bicep curl
Set yourself up on a swiss ball where your upper body is approximately at a 45 degree incline to do incline curl, with your elbows supported on the swiss ball. Set a weight you could only use for 10 reps. As you progress, your last sets would harder to reach 10 reps so when you get stuck lets say half way up, roll back on the ball to help the weight up. The ball will be the anchor on your elbows. Once the weight is up, put yourself back a t 45 degrees and lower the weight under strict tempo and control. Do 1-2 more reps like that, they are legal and very effective.
DB fly eccentric accentuated.
Same as the 10 rep max scheme, but for chest db fly. Reach your 10 rep max weight. Once you reach concentric failure, crank out as many reps as possible lowering the as a Fly (wide) and use the regular DB press for the concentric phase (lifting them up).
Enjoy the gains