Well, it turns out... someone explained this to me yesterday--when you go from a mile high to sea level, it takes 2 days to lose all those extra high-altitude blood platelets, but returning to the mountains, 2 weeks to recover them. Those are the little magic bits that make breathing better at altitude. So there's that. I was still feeling so exhausted over the weekend as Charlie and I attended the local COSINE event, and that's where someone suggested the platelets thing could be part of it.... Sign in to see full entry.