3 days a week is best for a natural if you lift heavy imo. Thats what im doing right now and im making very good gains. I have seen some naturals get pretty damn big on 3 days a week. Chest/triceps--legs--back biceps every 7 days. If i had the time i would add cardio and abs one extra day but i dont, and im making good progress. I drink 40-50 grams of whey protein 7 days a week, eat clean and take glutaimine/bcaa powder/zma and tribex along with Carlsons liquid fish oil. my best is a 315 incline a few years ago, im steadily getting back there now.