regressing curl reps

[gnoll]

so i started working out hard about 4 months ago-not long. ive gotten some good results however, with moderate weight increases. it seems that lately tho, my concentration curls are actually becoming weaker, as i could easily do 12-14 reps, but now seem to be able to only muster 10-12. why would this be? im not losing weight at all, no real size increases/decreases, just seem to fatigue quicker. am i overtraining this part?

[rookie]

well have you changed what time you go to the gym? i go to the gym at night always since i was alot younger, and if i go to the gym early in the mourning i feel like puking for some reason. and maybe your pre workout meal isnt what it should be try eating oatmeal b4 u lift, and drink a gatordae of some sort, always works for me.

[gnoll]

oddly enough, i didnt change my diet or anything but added 10 lbs weight on the dumbells and i can curl 6-8 good ones again. weird.....