I don’t get PEM or crashing from physical exertion and never have since the beginning. I get the worse of my PEM from mental over exertion which can be just being on a computer too long or socializing. I can say for certain that long car trips (more than 3hours) give me massive PEM for days. I don’t even do any of he driving so I am assuming it is from just watching the scenery go by? I am wondering if my brain is being super overstimulated. Does anyone else get this from car rides?