The New York City Marathon has come a long way since it first started in 1970 when 127 runners paid a $1 entry fee to loop around Central Park three times. Forty-five years since its founding, the race has become the most popular marathon in the world, drawing upwards of 50,000 participants. If you look closely in the sea of runners that cross the five boroughs for this year’s marathon on November 1, you might even spot a celebrity, too.
Stars love to challenge themselves to this 26.2 mile feat, mostly because they treat the marathon as an opportunity to raise money and awareness for a cause close to their hearts. In the past, Diddy logged miles to muster up money for public city schools, Ryan Reynolds ran for Parkinson’s disease research, and Edward Norton pounded the pavement to help save the wilderness. This year, there will be another set of stars lacing up their sneakers to make a difference, including Alicia Keys. The New York native and Grammy-award winning singer will be running her very first marathon to raise awareness for Keep A Child Alive, which provides healthcare and awareness to HIV- and AIDs-afflicted communities in Africa and India.
And she’s not the only one. Scroll down to see who else is pushing their bodies to the limits in 2015’s race—and find out why they’re running.