The 52-year-old is on a quest to run 20 marathons in 2016.
Here's a quick glance at the course with a few interesting notes.
The documentary is scheduled to be released in spring 2017.
The last two weeks before Boston are a time to let the body and mind freshen up.
A first look at this year's special edition shoes for the Boston Marathon.
Running fans have been waiting for Neely Spence Gracey to race a marathon for a long time.
Amy Cragg, Desiree Linden, Shalane Flanagan and Meb Keflezighi will all throw out the first pitch at Fenway Park on April 16.
The Boston Marathon is fast approaching! Greg McMillan outlines key training principles for the final 4 weeks of training.
Fifty years ago, Bobbi Gibb, the first woman to run the Boston Marathon, changed the world. Then the world forgot her.
The broadcast will start at 8:30 a.m. ET on April 18.