I'm pretty sure people have always had muscles.:-?
We use era in formal writing to refer to historical periods. It doesn't work (except in an ironic sense) for other time periods.
You had to write something, tufguy? Who's making you do it?
"When our parents were kids a lot of people didn't have muscles ...
No. '...to put it into context.'Is it correct to say "put it in the disscusion?"
Nonsense. Read post #2."When our parents were kids a lot of people didn't have muscles but people started building muscles when our time came."
No. '...to put it into context.'
Nonsense. Read post #2.