It should be minimal effort, Jalilah. The first sets are to let those muscles know they are about to be worked. It 'wakes them up'. I *can* tricep kickback 20 lbs but for the first two sets in a BFL style workout I would start with 10lbs, then 15 lbs then 17 lbs then 20 lbs - the 10 and 15 will not 'burn' or take much effort, but they do count and they do make an impact. If it makes you feel as though you're doing more practice squeezing the muscle isolated when you are at the peak of the exercise (i.e., straighten the arm to the count of 4 - hold and squeeze the tricep for one second - then bend the arm back to the starting position to a count of 4).

What is important with these two sets (and with all) is that your movements are slow and controlled and that you execute them with perfect form. If it takes 3 lbs to start, it takes 3 lbs. It's all about progress, not the numbers

Nat