its called riding bmx, mountain bike, rock climbing, breakdancing, and going to the gym constantly. they just dont get sore. im sure if i lifted 5 days a week AND went riding and climbing every day i could get some serious overtraining issues- or at least tendonitis. at this point i think i dont have muscle there, but a big tendon.
as far as sets and reps with weight, low weight and high reps dont do shit but make them tired after a while, like 4x10s. high weights and low reps like a 10x3 just doesnt do much for my biceps either- even near failure they dont feel stressed, just tired.
now, i may have been a little overzeous about stating 5x a week bicep training wouldnt do shit to me, but i have truly never been able overtrain biceps with lifting weights alone. i have done 4x a week curls along with biking and climbing. i think that my strength could have been much stronger with more rest, but my endurance at bodyweight was all that mattered, and thats a whole nother topic.
theres one part that i overtrain very easily, my top traps. they get sore and weak just thinking aabout lifting.