The 26-year-old is determined following the disappointment of needing to pull out of the Olympic Trials due to injury.
The expo welcomed thousands ahead of Marathon Monday.
The serial racer is aiming to run all six World Marathon Majors in 2016.
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.