I think Ronaldo is doing a great job at staying as fit as he is. He still works hard and though he may be perceived as being old, I think he's still quite relevant in the team. If not for anything else, for motivational purposes in boosting the morale of the team.
There was an attempt he made at goal with a header from a corner kick. Springing up and above everyone else, I knew he still got it.
Staying fit is the routine activities for Ronaldo because that is the side he make sure he doesn't disregard so that he might not be negatively affected as the age is closing up on him, so actually we can see that those things are really helping him even if we might think that a certain cannot be cheating from the performance of the person but is only few that is on the age with him and still fit as he does, when Ronaldo is in possession of the ball he is like a 26 years old players, however I love his influence on there national team because he has motivated the team a lot and he is the best for springing and he always get the chance than any other person.