People often assume the hardest battles happen on race day. The cold water before sunrise. The burning legs during the final kilometers of a run. The endless intervals that nobody sees. They're wrong. The hardest battles are usually invisible. They happen in ordinary mornings, when life feels uncertain but the alarm still rings at 5:30 a.m. They happen when motivation disappears, yet your running shoes are still waiting by the door. For years, I believed endurance was somethi