Hi how many dumbbell curls should i do and how many sets? also how long will it take to see some changes? ive been doing some dumbbell curls and the next day my arm muscles are sore is this because its getting stronger or am i doing it wrong?

I’m basically an average joe. Not looking to be a body builder, just maybe an extra 10 lbs of muscle or so. Do I need to do both dumbbell curls and concentration curls, or just dumbbell curls, to get nice biceps?

I currently do 12 reps on one arm without stopping and then doing the same on the other arm using just one dumbbell. Is that fine or is it better to have two dumbbells and alternate sides after each rep?

Okay, for muscle mass in the biceps, I do dumbbell curls. At the moment I am doing dumbbell curls with a 28 lbs dumbbell till failure (usually 6-8 reps)
How many sets should I do?? How much rest in between each set also?
Thank you.

I want to grow up bigger bicep.I have two 20 pounds of dumbbell and I do 20 reps of 8 sets of dumbbell curls three days a week,am I over training please suggest me.