First off, we should differentiate "aging" from "biological breakdown".

For most of the recorded history, people AGED at the same pace (barring some rare local anomalies like Okinawans), but living conditions would affect how long would they live, due to diseases or injury. Basically however, the greatest mortality rate was for among infants and children, and living past the age of 4 was already an achievement in longevity. After that, humans have had lived to more or less 60-70 years old, unless there was an unrelated cause of demise (which, depending on the times, culture and geography could happen a lot, or almost never).

We cannot say with certainity how old people LOOKED, when they were past their prime in say, 1100 ad, but from archeological evidence we can say that they often remained physically engaged untill late in age.

For example, sceletal remains from some medieval battles (like Visby) show that men well past their 50 would still engage in combat, and not only as a last line of defense, or something like that, but sometimes as raiders. Osteoanalysis shows examples like one where a man had his shinbone broken in hes early 20ties, recovered, then recieved an axe-wound that peierced his skull at the age of 40, recovered from that, and finally died at The Battle of Tannenberg in 1410, from an arrow to the spine, in his late 60'ties.

In essence, people of the past would have a smaller chance to survive untill adulthood, but those few who would get there, would often be sturdy enough to work, fight and generally be active until a late age.