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. Although, it went wide, I thought that was a nice attempt and pretty good for an "old" player.
He may not be as hot as he was in his prime, he still knows what needs to be done and strives to do it.
Hasn't shown that he is old. If you look at the game Ronaldo showed, Martinez is very aware of how to take advantage of Ronaldo's greatness. The Portuguese team seems to know what they have to do for Cristiano Ronaldo so that Ronaldo does not waste the opportunity to open the score.
The jump is still okay. The kick is still okay. Body is still okay, it's just the running speed that has reduced from Ronaldo.
In the final against either Spain or France, we will see what Ronaldo can do for Portugal.