Im wondering how long i should be waiting before doing another set. Right now im doing 70 pound barbel curls 7 - 8 reps waiting 3 minutes then doing the same but thats all i can do without waiting longer and i do the same for exercise's like seated tricep press's and deltoid exercise's. Im just wondering if i should keep doing 2 sets or wait longer cause ive also heard you should do 8 reps and wait 10 - 15 minutes and do that till you have done 5 sets but then some people say not to wait that long.