I am looking to start a new workout next week and want to build mass. I am currently on a 5 day a week wo but I go 6 days a week with sunday being my day off. So I basically hit each part every 6 days. I want to hit each body part every 3 days-4 days. Sunday has to be my off day. Do I go heavy on the first 3 and light weight with higher reps on days 4-6? Or is there a better way to go about this?