Conor doesn't have a cardio problem, hell he made Nate fight like Clay Guida in the 5th because Nate was too exhausted and was getting lit up by Conor.
Conor's output in the Diaz fight was the same as Edgar's and Aldo's combined in their rematch, and Conor faced a guy who had a higher output than himself. So it's easy to see why Conor and Nate were exhausted seeing as how both pushed the other so much.
Aldo doesn't have to tools the keep the pace that Conor fights at, and has to try and neutralize it with Kicks or TD's, but if those are unsuccessful, Aldo will fade faster than Conor, and will get stopped again.
Conor's output in the Diaz fight was the same as Edgar's and Aldo's combined in their rematch, and Conor faced a guy who had a higher output than himself. So it's easy to see why Conor and Nate were exhausted seeing as how both pushed the other so much.
Aldo doesn't have to tools the keep the pace that Conor fights at, and has to try and neutralize it with Kicks or TD's, but if those are unsuccessful, Aldo will fade faster than Conor, and will get stopped again.