It looks like you're new here. If you want to get involved, click one of these buttons!
My Missis has been a fairly serious runner for some years; she trains six days per week, is a club runner, runs marathons, etc. She's 39.
But she's used a heart rate monitor for the first time, took it on a hill training session and thrashed the life out of herself and her heart rate monitor recorded a reading of 247 Beats per minute.
Is this possible?