normally i can figure out things like this but not this time, anyways my question is kinda complex but here it is. when your train very intensely, your heart rate increases to supply your body with enough oxygen to keep you going, so your racing heart is a good thing in this situation (if one is in good health) this much is obvious. so my question is this, when training while using stimulants that tend to further increase you HR(assuming its a stim that doesent make you feel like you are about to have a heart attack like when on clen), is this further conditioning your heart/body in a good way and is it better then what your HR would be without stims because you would think your muscles are getting even more oxygen? or is it still over doing it?