Having trained with a professional MMA fighter and a really good Muay Thai fighter, I can tell you these guys have rock hard shins. They need shins that hard not only because they use them as a weapon, but because the proper way to block a low kick with your shin. In other words, it’s a shin on shin hit. Of course, there are levels to MMA. This is what the top level looks like. Don’t try this at home kids.