Keeping on the subject of tough "sports": an article about the Pakistani version of Polo. It says:

"Some regulations were introduced about five years ago to cut down on fights. Now bashing an opponent in the face or hacking his horse's legs are illegal, said the touch judge, Yaqub Masroof. "But only if it is intentional."
The best players have a strong horse, a wrench-like wrist and a backside of rubber. Still, injuries are common. Legs are broken, skulls cracked, and one player died from a heart attack mid-match."