when the dumbells get into the 140 + weight every 5 lb increase is felt alot imo,just because a person can do 150 pounders for 8 good reps doesnt mean he will be doin the 160,s for the same reps in 5 months or so.most of us will never be able to handle the 170,s in our lifetime nevermind the 200,s,im sure some of you can and will but unfortunataly most of us wont