NEW YORK CITY (WABC) -- More than 50,000 athletes will be taking part in the 2016 TCS New York City Marathon.
Among the runners is Genevieve Shaw Brown, a mother raising money for Down syndrome awareness.
As if running a marathon isn't hard enough, she's going to be doing something a little tricky -- changing her shirt -- at each mile marker.
Check out the video above to learn more about her message.