Fightworld

In Thailand, Grillo sees firsthand why muay thai is known as "the art of eight limbs." Later, he visits a true titan of the sport.

Fighters from around the world travel to Myanmar for the World Lethwei Championship. Also, Grillo trains with an elite fighter.

Grillo -- along with countless passionate fans -- gets caught up in the pageantry as two highly respected Senegalese wrestlers prepare to battle.

In Israel, Grillo receives a lesson on Krav Maga, a unique style of hand-to-hand combat used by citizens and military forces alike.