You know the number. Maybe it’s a sub-4 marathon, a sub-7 mile, or another barrier you’re determined to break. No matter what it is for you, there’s no greater feeling than finally achieving a speed ...

The sub-three-hour marathon is one of running’s most coveted milestones. It means averaging 6:52 per mile for 26.2 miles, a pace that demands not just fitness but—for many runners—a near-perfect ...