Steve's neck has been broken in the wrestling ring as well. He continues to train, like Sly, with the energy of a teenager. They wake up every morning realizing, there is no tomorrow, and they go at it.
Another cast member, Jason Statham at age 37, was the baby. He trains specifically for every movie, with a former Navy SEAL, Logan Hood. Their workouts would dismantle many gym monkeys.
Last but not least is legendary UFC fighter, Randy Couture. At 47, many men are complaining about pain and sporting a fat stomach. Randy is making top box offices movies and winning fights in the Octagon agains decades younger opponents.
The point here is that age, injury, mobility, and function are largely between the ears. You can listen to your friends, your family, your doctor, the internet, or you can listen to yourself. The men above answer to the only person that counts,... themselves. Keep mobile, keep strong, and keep trying.