I thought doing iso-hold for 2 seconds on the tops of de movement, good ?[/quote]
The general idea is good but I would say do it mid-range because generally when you’re curling, the top portion is where your biceps are least activated.
What I did to get a good mind muscle connection with biceps is light weight concentration curls where I put my index finger of the opposite hand on my bicep and focus on really feeling it.
As for volume, your biceps recover quickly so I would say doing them twice a week is best, but do less weight or less volume every other day. Don’t double the volume - more like add 50%. That’s what I did when my bi’s were lagging to bring them up and it worked pretty great.
I wanna ask people in this thread a question. What do you think about the range of motion requirement for biceps? I used to think that you needed full range of motion for every exercise (straight bar curls, preacher, etc) but now I find my biceps grow better with a little of both. For example, I’ll do a lot of partial ROM preacher curls, really focusing on feeling the muscle, along with full ROM straight bar and dumbbell curls.