A 70-year-old grandfather-of-eight from north-west London says regularly playing rugby for his local club makes his brain and bones "much stronger".
John Goldman from Hendon appears as a prop for Mill Hill Rugby Club and said he "can't see any reason to stop".
In the past 20 years he has had cancer, a heart bypass and major back surgery.
He said he did not see why he should be planning to "wind down", adding he would keep playing until he began to "look pretty ridiculous".
The father-of-four, who has played for Mill Hill for 14 years, said he practised pilates to maintain his posture and did not shy away from tackles or scrums.
"It seems to be a kind of philosophy or a train of thought [that] when you get to a certain age, you are looking to retire and looking to wind down. Why?
"I think the brain, the bones and everything else are much stronger.
"When I start to look pretty ridiculous - probably I do already - but when I can't get a game, that's the time to stop."