4-time Olympian Shalane Flanagan retires from professional running

In 2017, Shalane Flanagan became the first American woman to win the New York Marathon in 40 years.

(CNN)Shalane Flanagan, a four-time Olympian and the winner of the 2017 New York City Marathon, has announced her retirement after 15 years at age 38.

"With happy tears I announce today that I am retiring from professional running," Flanagan wrote in an Instagram post. "From 2004 to 2019 I've given everything that's within me to this sport and wow it's been an incredible ride!"
View this post on Instagram

With happy tears I announce today that I am retiring from professional running. From 2004 to 2019 I've given everything that's within me to this sport and wow it's been an incredible ride! I've broken bones, torn tendons, and lost too many toenails to count. I've experienced otherworldly highs and abysmal lows. I've loved (and learned from) it all. Over the last 15 years I found out what I was capable of, and it was more than I ever dreamed possible. Now that all is said and done, I am most proud of the consistently high level of running I produced year after year. No matter what I accomplished the year before, it never got any easier. Each season, each race was hard, so hard. But this I know to be true: hard things are wonderful, beautiful, and give meaning to life. I've loved having an intense sense of purpose. For 15 years I've woken up every day knowing I was exactly where I needed to be. The feeling of pressing the threshold of my mental and physical limits has been bliss. I've gone to bed with a giant tired smile on my face and woken up with the same smile. My obsession to put one foot in front of the other, as quickly as I can, has given me so much joy. However, I have felt my North Star shifting, my passion and purpose is no longer about MY running; it's more and more about those around me. All I've ever known, in my approach to anything, is going ALL IN. So I'm carrying this to coaching. I want to be consumed with serving others the way I have been consumed with being the best athlete I can be. I am privileged to announce I am now a professional coach of the Nike Bowerman Track Club. This amazing opportunity in front of me, to give back to the sport, that gave me so much, is not lost on me. I've pinched myself numerous times to make sure this is real. I am well aware that retirement for professional athletes can be an extremely hard transition. I am lucky, as I know already, that coaching will bring me as much joy and heartache that my own running career gave me. I believe we are meant to inspire one another, we are meant to learn from one another. Sharing everything I've learned about and from running is what I'm meant to do now.(1/2)

A post shared by Shalane Flanagan (@shalaneflanagan) on

Flanagan is best known for becoming the first American woman to win the New York City Marathon in 40 years when she won in 2017. She also won bronze in the 2008 Olympics in Beijing in the 10,000 meters, which nine years later was upgraded to silver because the second-place finisher tested positive for doping. Flanagan competed in the Olympics in 2004, 2008, 2012 and 2016.
Her final race was the New York City Marathon in 2018, in which she finished third. She underwent knee surgery in April.
    Flanagan was part of a resurgence by American women, including 2018 Boston Marathon champion Des Linden, in the marathon on the world stage.
    "I hope I made myself a better person by running," Flanagan wrote. "I hope I made those around me better. I hope I made my competition better. I hope I left the sport better because I was a part of it.
    "My personal motto through out my career has been to make decisions that leave me with "no regrets".....but to be honest, I have one.
    "I regret I can't do it all over again."