That's exactly what he'd be doing
A few days ago he was on a cocktail of experimental drugs. A fat 74 year old doesn't beat it that quick. But his persona relies on him being a superman. That's why he always uses the word 'strong' and talks about his good genes.
He won't allow anything that makes him look weak, even though all but his biggest enemies would sympathise with him saying 'look, I'm feeling pretty bad from this'. Instead he says he feels the best he has in 20 years. It's totally implausible.