I heard a few years back from guys in Steve Michalik's Mr. America's Gym (1985) that Arnold went from:
Off-Season: 4x/wk, Bodyparts 1x/wk
Mid : 5x/wk, Bodybarts 2x/wk,except Arms & Legs 1x/wk
Pre-Contest: 6x/wk, All Bodyparts 2x/wk
Supposedly, 10-12...