Is Salvador Sanchez' stamina purely based on genetics?

Don't discount living up in those Mexican mountains, man. It's part of why those Kenyans do so well too in endurance sports.

The biggest what if in the history of boxing for me

Some people have genetically higher capacity for cardio vascular work. Look at those East-African marathon runners they can run 26 miles in 2 hours like it's nothing. Sanchez trained and lived at altitude but is likely to be one of those people with freakish cardio capacity. Ally that to being a superb boxer with a granite chin and the heart of lion. That's one guy you don't want to fight.

A mixture of great work ethic and the right conditions to thrive such as training in high latitudes. He shouldn't have been as good as he was at 23 years old beating the likes of Danny Lopez X2, Ruben Castillo, Azumah Nelson, Juan Laporte, and Wilfredo Gomez. Makes you wonder how his career would have been if he had lived another 10 years. Man he could had fought: HOFs or ATGs at 126-135 like: -Alexis Arguello -Julio Cesar Chavez -Edwin Rosario -Ruben Olivares -Eusebio Pedroza The were also the ferocious five of the featherweight class: -Bobby Chacon (Has wins over Lopez, Limon, Castillo and Edwards) -Chucho Castillo (Has wins over Medel and Olivares) -Rafael Limon (Has wins over Chacon and Naverrete) -Cornelius Boza Edwards. (Has wins over Chacon and Limon) -Rolando Navarrete (Has wins over Limon and Edwards)

I also heard that he would do 8 miles of roadwork, compared to Ali who would do just 3 miles Yup I recall reading an old issue of the ring magazine that his workouts were insane according to Bert Sugar one of the most extreme he had seen during his time. Another guy similar to Sanchez was Pryor. He was a whirlwind and even when you thought he might be fading he would find that 2nd wind and come out like it was the first rd. Some guys are just built different and both Sanchez and Pryor certainly were.

Altitude and yes every human being is different rumor had it that Sal would spar crazy amount of rds back to back without the minute rest. He would have one guy ready to jump In after 3 straight with another. So basically one long 9 min rd then switch to a different guy since most couldn't keep that pace. I also heard that he would do 8 miles of roadwork, compared to Ali who would do just 3 miles

Altitude and yes every human being is different rumor had it that Sal would spar crazy amount of rds back to back without the minute rest. He would have one guy ready to jump In after 3 straight with another. So basically one long 9 min rd then switch to a different guy since most couldn't keep that pace.