a short question if you don't mind.
I bench twice a week and near the end of each bench workout I do 3-4 sets light Dumbell benching. I do them very fast 30 reps in around 20 seconds. I try to generate as much power as I can, pushing them up and pulling them down (while still trying to use my pecs, tris, delts). The weight is not very heavy for me and I go to "failure" that means after around 25-30 reps I can't fully extend my arms anymore.
What does this train ? Does it help me to bench more or does it a good job at building muscle ? For strenght should I switch to a bodybuilding Dumbell bench press style with slow reps ?