What sports fly under the radar for toughness?

I’m always fascinated by the physical challenges in sports that don’t get much mainstream attention. For example, I’ve heard rock climbing demands incredible grip strength and full-body control, but what about the wear and tear on joints over time? Or take rugby sevens it seems like non-stop sprinting and tackling with hardly any breaks. Are there other sports out there where the injury risks or fitness demands are way higher than people realize? I’d love to hear your thoughts or experiences with less common athletic pursuits.