It depends what you do. One of the reasons i picked an electrician, it wasn't that physically demanding. And yes after time you are the Journeyman, you get apprentices to do all the lugging while you supervise and go over somethings.
I know welders who make 200,000 per six months working on the pipelines. That is physically hard but the pay is very good. High pressure welders make big big big money.
Plumbers have more lugging and millwrights have some as well. But don't think our bodies break down, some do sure but others are fine and like i said you have apprentices under you who do the work. I will retire at 50 years old and no regrets and i certainly haven't killed myself.