Marquez-Pac 4 shows the importance of strength and conditioning
A proper periodised strength and conditioning program can make a big difference as shown by Marquez' obvious increase in punching power for this fight. Pacquiao looked good in terms of his boxing but he was clearly outgunned. Note that Ariza claimed Pac hadn't been following his strength program. People are going to call PED's just like when Pacquiao moved up and started proper conditioning but that's because boxing is 'old school' and full of uneducated opinions.
The old 'punchers are born' line should be thrown away, there's no reason not to embrace modern training methods and boxing coaches need to get that through their thick heads.