[dempsey1234]

Salvador Sanchez, conditioned himself the Mexican way at altitude and good old fashioned hard work, sparring, callistetics and sparring. He was always running the hills and mountains where he lived. He had a Dr Valenzuela who worked with him and on his stamina. Dr Valenzuela was an early S&C coach. Sanchez had savy old school guys who were open to new ideas and would bring in private doctors to camp to ck the fighters heart rate something they do now.
The best Mexican trainers, Cuyo Hernandez, Lupe Sanchez, Nacho Beristain, Pancho Rosales, Cristobal Rosas, Romulo Quiarte, all used private doctors, sports medicine guys. If I am not mistaken even before the '60's, there was a doctor ready to ck the heartrate of the fighters.