It wasn't the runs in the dark in the middle of winter at 4 a.m and again at 10 p.m. It wasn't leaving my son's hospital bed to go do a high-intensity interval class instead of showering for the first time in three days or sleep. It wasn't when I fainted after running a marathon followed by an hour of kickboxing - can't miss a workout! - without drinking or eating anything and then being carried down the gym stairs by a friend who tried to make me drink a Vitamin Water which I refused because it had 50 calories. It wasn't even when my heart started doing this weird sick jumping in my chest and I briefly wondered if I was going to die on the floor in front of my young children.