What makes it so tough is the fact that rounds require five minutes of constant contact between competitors .
If this ca n't be done , matches can also end by pinning an opponent on his back or submitting them through a stranglehold or an arm lock .
What makes it so tough is the fact that rounds require five minutes of constant contact between competitors .
If this ca n't be done , matches can also end by pinning an opponent on his back or submitting them through a stranglehold or an arm lock .