Some aged, even old people, due to their breed and healthy, active lifestyle, not only look very well, but sometimes are also able to compete with much younger ones in some activities requiring agility, physical strength, and stamina.
I've been thinking about the best way to describe such people in general and came up with the expression "to wear well/greatly". I haven't been able to find the proofs that this expression is valid for human beings, though, and if it is, whether it can be used as in this sentence:
Tom's grandfather wears greatly — not only he looks much younger his age, he also seems to be stronger than most of his grandson classmates' dads.
Are there words and expressions to describe such people in English like I tried to do it in this sentence? What may be some of them, the most commonly used ones?