PIC: Pregnant Reese Witherspoon Goes Jogging!

Reese Witherspoon jogging in Brentwood, California on April 24, 2012. RAMEY PHOTO

Reese Witherspoon isn't using her pregnancy as an excuse to become a couch potato.

The married actress, 37, kept up with her fitness by jogging with a pal in the Brentwood area of L.A. Tuesday. The longtime runner (and mom to Ava, 12, and Deacon, 8, with ex-husband Ryan Phillippe) showed off her growing baby bump in tight black workout gear. See more pics of Reese Witherspoon's workout.

For a brief time, the This Means War star had given up her daily runs after being hit by an 85-year-old driver in September 2011. "They said I am very hard-headed because I landed right on my head and I have a scar," she later explained on The Graham Norton Show. "I don't remember much about it, but miraculously — and thank God! — I am fine."

With the accident far behind her, Witherspoon and her husband of one year, high-powered CAA agent Jim Toth, 41, are "so happy" to welcome their first child together later this year. "They're big family people," a source recently explained to Us Weekly.

Ava and Deacon "will love having a baby brother or sister," the source added. "Ava has always been the oldest kid around friends and family because Reese had her so young. They have little cousins who they are close to and have a lot of experience with little ones."

Sign up now for the Us Weekly newsletter to get breaking celebrity news, hot pics and more delivered straight to your inbox!

Want stories like these delivered straight to your phone? Download the Us Weekly iPhone app now!