If you’re one of the many getting ready for a fall marathon, like New York City or Marine Corps, then good luck. Running a marathon is a huge accomplishment, be it your first or 40th. Besides worrying about just finishing, the thing most marathoners worry about, especially veteran ones, is their time. How fast they can run and how long it takes them to finish 26.2 miles. Marathoners tend to obsess over mile split times, energy drinks, gels, the weight of their shoes, the exact temperature at the 20-mile mark – pretty much anything that might take a few minutes, or even seconds off their time. Sometimes it’s to break a well-known barrier – like a four hour or three hour marathon. Sometimes it’s simply to get a personal best, say one minute better than last time. Or if you’re like me and on the back side of a running career, it’s simply not to go too much slower than last time. Whatever it is, pretty much every one that lines up for that fabled distance goes in with an aspirational finish time.