I think the answer is "No." So here goes:
I want to lift 60 pounds smoothly about 45 times in an hour (to assist with archery target practice with 60 pound bow).
Right now I can only lift 60 pounds about 5 times before I start shaking (read: overbowed).
Once I reach this goal, it is not necessary for me to continue growing in strength or endurance.
Is it possible to train with weights that are around 20 to 40 pounds and reach the stated goal? Or is it inevitable that eventually I have to work out with 60 pound weights?