i dunno, i think that line is non-existant and it's just perception..... cuz the major body responses between both, are mirror like... seriously... look at the one major factor of both... ADRENALINE..... durring 'both' experiences, adrenaline is pumping like fucking crazy... some like it, some don't.. i'm inclined ot say those who like it, think of it as a rush, and those who don't call it being scared...