So,

Today, it's a whole industry. You got gyms, protein shakes fitness bloggers and all that jazz.

But when did people start working out? When did it become common? I can only ever remember like 80's workout tapes as "old-timey workout for the masses".

I get that in like medieval times and later on, with practically everybody toiling away doing physical labour, there was no need for working out, but maybe nobles did it? What about 1780-ies borgouise? Was for instance Robespierre swole?