Do you think roger Gracie does not know how to control his cardio while grappling? Really? His weight was too much, that's the answer in why roger gassed, not because tim Kennedy.... Although having to constantly break someonelsws grip on your gloves takes a shit ton of cardio, similar with what happens to silva This past weekend...
The adrenaline rush, pace, and exertion of an MMA fight can make you gas out way faster then a grappling match