Brian Metzler has run more than 50,000 miles in his life, tested more than 750 pairs of running shoes, and raced just about every distance from 50 yards to 100 miles. He is Editor-in-Chief of Competitor magazine and was the founding editor of TrailRunner and Adventure Sports magazines and was Senior Editor for Running Times. Metzler has written about endurance sports for Runner's World, Triathlete, Inside Triathlon, Men's Health, Men's Journal, and Outside. He is the author of Running Colorado's Front Range and co-wrote Natural Running with Danny Abshire and Run Like a Champion with Alan Culpe...