Run Like a Pro
Focus on maintaining good form by tightening your core, leaning your upper torso forward, and thrusting your arms.
Train Twice as Hard
"Build your endurance with dual cardio workouts," Karnazes says. "Do cardio in the morning and repeat it in the evening — a minimum of 45 minutes each on the treadmill, the elliptical, or whatever your preferred machine is."
Put on the Blinders
"Ignore any sort of mile markers," Karnazes says. "Inevitably, you'll look at them, see how much distance you have left, and think you can't go on." Instead, focus your attention on your form.
Listen to Your Body
A cramp or gut stitch is a surefire way to lose time on the course. But ignoring it is even worse. "It's painful, but you've really got to slow down and work through it." Since cramps are caused by oxygen and electrolyte deficiencies, breathe deeply to pump in fresh oxygen to your muscles, and if possible, swig a salt tablet with an electrolyte beverage.