The following routine used Casey in his teenager years. In his adult hood he used to vary all the time. He never stayed on the same routine.
The best training article on Casey during his 20s was written by Achilles Kallos and published in the October 1971 edition of Iron Man. This article listed Casey's measurements as height 5 ft 8 inch, bodyweight 217lb, arms 19 3/8in (cold), chest 50inch, waist 31 1/2 inch, thighs 28 inch and calves 18 inch.
He trained 3 times per week his whole body in one workout! The young Casey used to train 2 and 2 1/2 hours!
Leg Press: 1 set 20 reps with 750lb
Leg extension: 1 set of 14-20 reps 250lb
Squat: One set of 14 - 20 reps with 505 pounds
Leg Curl: 1 set of 14 - 20 reps 150lb
Note: Most amazing thing about his leg training was that Casey did each exercise nonstop, going from one exercise to another without rest!
Lats (normal sets)
Nautilus Pullover Machine 3 x 20reps
Nautilus Circular Pulldown 3 x 20 reps
Chins 3 x 20 reps
Standing Lateral Side Raise 3 x 20 reps 60lbs
Behind the Neck Press 3 x 20 reps 215lbs
Nautilus Spedal Side Raise 3 x 20 reps
Shoulder Shrugs 3 sets 20 reps 280lb
Bench press 2 x 20reps 350lbs
Incline Barbell Press 3 x 20reps 225lb
Parallel dips 3 x 20reps 100lb
Cable crossovers 3 x 20reps 40lb
Barbell curl 1 x 20 reps 200lbs
Nautilus Biceps Curl 1 x 20
Nautilus Triceps 1 x 20 reps 120lb
Nautilus Pushdown 1 set 20 reps with 110 pound
Compound Triceps Movement 1 set of 20 reps
Seated Barbell Calf Raise: Two sets of 20 reps
Wrist curl 2 x 20reps
Deadlifts 1 x 30reps 400lbs
The above routine was devloped by his coach Arthur Jones (he also invented the Nautilus Machine). In 1970 Mr. America Casey placed third. Arthur saw this kid and pulled him aside. He said: "Casey, you have to the potential to become the greatest bodybuilder in the world, but you are training way too often. You need to cut back on your sets and length of your workout."
After this conversation Casey followed the above routine and won the Mr. America title in 1971.
Before winning Mr. America 71 and meeting Arthur he trained like a mad man. He mostly followed split routines in his training with as much intensity that he possibly could. He trained 3 hours. 40 sets a bodypart 5 days a week. But later in an old flex-interview (around 2000) he admitted to overtrain and trained in his teenage hood too much.