I was wondering what you heavy lifters thought of the Slim Series? I'm interested in trying them out, but I really do get bored with light weight, high rep workouts. If the reps are really high I usually have to lift light so that my shoulders can handle the weight, but in the process my biceps,triceps,back, and pecs get no kind of workout. I was wondering if this was one of those types of workouts? Or is the workout structured so that you can change weights to get a good high rep workouts for each part of the body?