It was detailed in a biography of Marco Pantani - referring to him and his peers. This was probably partly (at least) related to epo - the increased oxygen carr

It was detailed in a biography of Marco Pantani - referring to him and his peers. This was probably partly (at least) related to epo - the increased oxygen carrying capacity of the blood was probably what led to their exceptionally low heart rates. I’ve not read about this phenomenon outside of the epo-dominated era.