Curling is literally elbow flexion. The same movement you do everytime you do a chinup, row, etc. Only those movements have the added benefits of stressing much more muscle, and being more biomechanically relatable to most sports and activities of daily living. Unless youre referring to an arm wrestler, etc, i'd be curious what supposed benefit an athlete will get doing them vs doing compound movements. Does this mean theres anything wrong with doing them? Of course not. I dont see how throwing a few fluff sets of curls at the end of a workout is going to make much a difference one way or other, beyond perhaps a psych boost. Its just that I wouldnt consider very common exercise to program into the regimen of an athlete. Again, dont really care though. Just surprised when i see posters in this forum talking about curls non-ironically.