That hardly tells me anything because essentially everyone has a weaker heart than a professional cyclist. So they may be more capable of fighting off whatever

That hardly tells me anything because essentially everyone has a weaker heart than a professional cyclist. So they may be more capable of fighting off whatever hypothetical damage there is. It's like saying, "we threw a brick at 80% of NFL players and none of them were seriously injured by it. Therefore it is safe to have a brick thrown at you."