My wife missed so many beats when she was young that I used to leap up and shake her. She, to this day, is totally pragmatic about medical problems and back then just ignored my cries of horror.
With no training, she won the school mother's race coming waaaay ahead of the local tennis champion and yearly winner. A non event for her, but what we didn't know at that time was the statistical increase in stroke risk in later life. I don't understand the mechanics of that link at all.