Originally Posted by
MoAlpha
Excellent point. I can’t find a quick number for how much the heat response expands the vascular space that the heart has to pump blood through, but it’s big and you need big reserves to perform under those conditions, especially with the inevitable volume loss due to sweating.
I think it was RacerEx who posted some data about using an ice vest on a trainer, and even outside. Of course I don't remember any of it but it was obvious how it made a difference in performance.