I beg to differ. I have a number of friends who only train one body part a week and they are all freaky huge. Some use very high doses of juice but I know some that stick to moderate dosages and they look fuckin awesome. My old workout partner was 22 yrs old.,had been training since he was 13, had 20 inch arms(no exaggeration) and a 28 inch waist, he had washboard abs year round. I personally saw him bench 440 after warming up with 225(20reps) 315(15reps) 365(10reps)405(6reps). I mean the guy curled 225 on barbell curls for reps. He was 6'1" at 250lbs and about 8% bodyfat, he would ONLY use moderate doses of aas. I trained with him day in and day out for 1 yr. he was my best friend and I new what dosages he took and that fucker looked better than any bodybuilder I ever saw other than the pro's. Thats only one instance and I know of a couple others. I think it has to do with the way your own body reacts to training, some people need more rest than others.