For today’s edition of Dear Mark, I’m answering two questions from readers. First one comes from Debbie, a prolific hiker and backpacker who can’t seem to shake terrible thigh muscle cramps during steep climbs. She’s tried all the conventional advice. She’s taking electrolyte tabs. She’s staying hydrated. Nothing works. What does? And then, Brad wonders about parasympathetic overtraining, a type of overtraining you don’t hear much about. What does it mean and how should he respond?