Originally Posted by BendtheBar
I do as many reps as possible with good form. I'd rather add clean reps than cheat a dirty rep, especially when playing with heavy weight.
With that said my rows, curls and shrugs are explosive movements which are often misunderstood as cheat movements.
One can certainly call into play some momentum on the last rep or two for certain movements, but I only recommend this for the experienced lifter. You should only break form once you have mastered form and know your own body.
An explosive curl I've never seen.