Who had the best cardio or stamina in each weight class in boxing history?

Heavyweight: Probably has to be either Marciano or John L Sullivan. Different kind of stamina required in Sullivan’s bareknuckle days where there’s a lot of wrestling and such and not as much moving around. But to battle Jake Kilrain for however many hours it took in the Mississippi summer heat is ridiculous.

 

Super middleweight Joe Calzaghe.

 

Rocky Marciano heavyweight.

 

Henry Armstrong at featherweight
Ali or Frazier worthy of mention at heavyweight

 

Marciano wasn't a heavyweight he weighed 180 pounds. I can't think of 1 180 pound boxer who didn't have good stamina. Fighters in John L Sullivan's era threw few punches. It is easy to have good stamina when you only throw 3 punches per round.

 

I’m not going to bother explaining what a heavyweight is. Marciano, btw, was usually closer to 190 than 180.

Sullivan-Kilrain lasted 75 rounds covering 2 hours, 16 minutes. One round was 15 minutes, 3 seconds long. It was 104 degrees under the Mississippi summer sun.

Fighting under the London Prize Ring rules was different than today, but took great muscular stamina as it involved a lot of wrestling tactics as well as punches. Different sport, sort of, but not lacking in a need for great conditioning.

 

WW: Errol Spence
JMW: Tito
MW: Hagler

 

122 Bazooka Gomez
126 Armstrong
130
135 Chavez Sr
140 Pryor
147 Pacquiao
160 Harry Greb
168 Super Joe
175 Roy Jones Jr/Archie Moore
190 Holyfield
HW Wilson

130 is tricky as most leapfrogged that, wanting a shot at the LW strap.

 

Dwight Qawi comes to mind for his perpetual motion in the first Holyfield fight.

 

I probably agree that this is a category where the [very] old timers would often prove superior to today's fighters.

Lomachenko at his physical peak would take some beating.

 

I can't answer this question but Jeff Fenech comes to mind at bantam, super bantam and featherweight as having super cardio and stamina. Thanks to his trainer Johnny Lewis.

 

Pacquiao??? It was common knowledge he couldn't go all out for a full fight due to cramping not exactly good sign for stamina

 

Where is this common knowledge? Out in Pacland

 

Salvador Sanchez had the greatest stamina ever. The legend wouldn't even be breathing hard after a 15 round fight, and he had his mouth closed every single minute of every round.