POPSUGAR Celebrity Jake Gyllenhaal Slide Photo of Jake Gyllenhaal Running with Muscles Out Break a Sweat by Celebrity 10/01/09 0 Shares Like us on Facebook Sign up for our daily newsletter > Follow us on Pinterest Jake Gyllenhaal showed off his muscles on a run through Pittsburgh Wednesday. Image Source: Ginsburg/Spaly Inc Read More HotJake Gyllenhaal Jake Gyllenhaal The Mystery of Jake Gyllenhaal's Height Has FINALLY Been Solved . . . Right? Which Celebrities Are Godparents For Their Famous Friends? What Really Happened After Everest the Movie Ends? The Real-Life Survivor Story Jake Gyllenhaal Has a Hilarious Response to Amy Schumer's Cake Eating Confession POPSUGAR, the #1 independent media and technology company for women. Where more than 75 million women go for original, inspirational content that feeds their passions and interests. Be in the Know With OurCelebrity and Entertainment Newsletter Personalize A-Listers TV Movies Young Hollywood Sign up with facebook or By signing up, I agree to the Terms and to receive emails from POPSUGAR.