Another older RB I owned was Ottis Anderson:
Ottis Jerome "O.J." Anderson (born January 19, 1957
In 1989, Anderson become the top running back for Bill Parcells' ball control offense and was named NFL Comeback Player of the Year. He scored a career high 14 rushing touchdowns, and rushed for 1,023 yards on 325 carries. He was also the top running back for the Giants the following year, when they won Super Bowl XXV, and was named Super Bowl MVP for his 102 yards and a touchdown on 21 carries.
So here is another back that was going strong at 33.