All drugs.
Note the monster attempt to conceal ones identity? way to go.
This debate goes this way: those that are fans of Arnold, agree that in at least his prime, Arnold was 6'2". Those that arent Arnold supporters stay on the side that he's only 5'9" etc., etc.
What it boils down to is this; yes he's no longer 6'2". Having aged and taken part in an activity such as bodybuilding that compresses your spine, he is shorter and fully admits to wearing lifters in his boots. Or just wearing cowboy boots altogether to increase his height.
end discussion.