Reese Witherspoon Is Not Backing Down From Her Monthlong Run/Walk Challenge Shape 12/21/2020 Replay Video UP NEXT At the beginning of each month, Reese Witherspoon announces her Book Club’s latest pick and encourages fans to read along with her. And while this month was no different, she also kicked off December asking her followers to join in another monthlong activity: a run/walk challenge. Now, a few weeks into it, the 44-year-old star is taking to the gram to share updates on how she’s staying injury-free and committed to her self-made challenge. In a series of Instagram Stories po...