Retired NFL defensive end Isaac Rochell, 29, is preparing for the Chicago Marathon, aiming for a 3:15 finish.
Rochell, who played for the Chargers, Colts, Browns, and Raiders, admits that marathon training is "way harder than football."
"I went from wearing this jersey [NFL shirt] to this jersey [marathon bib]."
After announcing his retirement from football, Rochell has found a new challenge in marathon running, testing his discipline and endurance.
Author's summary: Retired NFL player takes on marathon challenge.