Legendary basketball player Shaquille O'Neal called mixed martial arts the hardest sport. In particular, he noted that during a fight according to MMA rules, fighters work every muscle.
“For example, in football, after hard contact, sometimes you can rest a little. But in MMA you need to work continuously for 3-5 minutes. Try to endure so much when someone chokes and beats you, and you will understand that this is the hardest sport,” added Shaquille.