Old?
That's relative but I take your point ...
Decrepit?
Hmm ...... the definition of that word is:-
weakened by old age; feeble; infirm: a decrepit man who can hardly walk.
I might have to disagree with that description on the basis that even though I'm 60, every Monday night, I coach boxers, all of whom are considerably younger than myself ... and not one of them, can outbox me, not even close - I hit harder and I hit faster, and therefore, I'm not decrepit, just yet anyways.
PS I better add, the boxers I refer to are aged 10 and 8
PPS Unbelievable and incredulous as it may seem, I actually can outbox all of them, two of whom are ex-amateurs with the remainder being novices.
Next week, I will see if I can still beat them when I take their blindfolds off ...