When Des woke up on April 16, 2018, the morning of the Boston Marathon, it was 39 degrees and raining, with high, gusty winds. The weather didn’t bother her. In fact, she thought it might be a blessing. She was far from peak form—recovering from illness and questioning her running future—and didn’t expect much of herself that day. But as she ticked off mile after mile in the brutal conditions, passing familiar landmarks on the course she knew and loved, something shifted. Opportunity unexpectedly presented itself. Des tapped into her inner strength and found a reason to race.

The road from a high school track to an Olympic starting line is long and sometimes shadowy. Obstacles like chronic injuries, under-fueled nutrition, and coercive coaching can threaten to derail careers before they’ve even begun. Frustrated by seeing young talent burn out before reaching their potential, professional distance runner Molly Huddle and college coach Sara Slattery have teamed up with trailblazing running legends and sports medicine professionals to create an essential guide to reach your running potential.

Kara Goucher grew up with Olympic dreams. She excelled at running from a young age and was offered a Nike sponsorship deal when she graduated from college. Then in 2004, she was invited to join a secretive, lavishly funded new team, dubbed the Nike Oregon Project. Coached by distance running legend Alberto Salazar, it seemed like the opportunity of a lifetime. Kara was soon winning a World Championship medal, going to the Olympics, and standing on the podium at the New York and Boston marathons, just like her coach. But behind the scenes, Salazar was hiding dark secrets.

Deena Kastor was a star youth runner with tremendous promise, yet her career almost ended after college, when her competitive method - run as hard as possible, for fear of losing - fostered a frustration and negativity and brought her to the brink of burnout. On the verge of quitting, she took a chance and moved to the high altitudes of Alamosa, Colorado, where legendary coach Joe Vigil had started the first professional distance-running team. There she encountered the idea that would transform her running career: the notion that changing her thinking - shaping her mind to be more encouraging, kind, and resilient - could make her faster than she’d ever imagined possible.

This revolutionary training method has been embraced by elite runners - with extraordinary results - and now you can do it, too. Respected running and fitness expert Matt Fitzgerald explains how the 80/20 running program - in which you do 80 percent of runs at a lower intensity and just 20 percent at a higher intensity - is the best change runners of all abilities can make to improve their performance.