not sure about all the guys in arnolds day,but a lot had other jobs,even Arnold and franco had a bricklaying co.nubret was a movie star in france,a lot of em owned their own gyms and in that day you could make a living off your own gym,especially if you were a bodybuilder,this was way before all the franchise pussy health clubs opened up.and most also had a lot shorter careers than boidybuilders of today,because there wasn't as much money in it.
That bricklaying story was debunked years ago...Those guys never did any manual labor.