Prep for Your Toughest Races Like a Master Marathoner

On Wednesday, I spoke with Mebrahtom Keflezighi, perhaps the most successful American marathoner of all time. He won the New York City marathon in 2009 and the Boston Marathon in 2014. He won an Olympic silver medal and was internationally competitive until the age of 42, in a sport where people tend to peak much younger than that. On Monday, he will be the grand marshall of the Boston Marathon. Keflezighi possesses a wealth of running wisdom, much of which he shares in his book 26 Marathons. We spoke mainly about the science of running fast in difficult conditions and about how to keep a career going as one ages. Nicholas Thompson: As someone who ran lots of difficult courses …