valid points made by everone
btw there have been lethal accidents @parisbrestparis as well.
but, for me, it boils down to “life isn’t safe”
ultra endurance is an extreme example but if you want to regulate it, aside from the practical issues: where to start,where to draw a line,… it would take away from the heart of the sport.
what about simulclimbing in mountaineering??
you do realise mountainbiking is safer @ moderate speeds
if I do tabata intervals while running my vision ALWAYS get very blurry (if not you’re not doing them right). Should I only be allowed to do them on the track??
etc…