By Larry Bugg
By Colon D. Joiner
By Chris Moling
By Laurie Parton Corbin From active.com
By Greg McMillan From Peak Running Performance
By Peter Gambaccini From active.com
By Stacy Sims, M.S. From Peak Running Performance
By Bob Schwartz From On the run
By Don Allison From Run The Planet
By Liz Applegate, Ph.D. From Runner's World
By Armand Tecco, M.Ed. From drkoop.com
By Karl Hempel, M.D. From The Health Gazette