That doesn't seem to be the case. Although agricultural peoples were often shorter, ancient peoples who were less settled frequently had better bone density tha

That doesn't seem to be the case. Although agricultural peoples were often shorter, ancient peoples who were less settled frequently had better bone density than moderns and were as tall. In both cases, most people were in much better shape than the average modern human. Look at the athletic stunts performed by the Greeks, from the professional athletes to the runners to the rowers. Trireme rowers outperformed modern Olympic rowers. I think you could pretty safely pit the average human being from pre-modern times and they would embarrass almost anyone except top athletes from today in physical fitness tests, and some of the better specimens would almost certainly be competitive even with those.