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 Which Celebrities Are Godparents For Their Famous Friends? The Hollywood Film Awards Basically Brought Out More Stars Than the Oscars Jake Gyllenhaal's Cowboy-Inspired Outfit Will Make You Want to Saddle Up Jake Gyllenhaal Basically Looks Like the Mountain Man of Your Dreams 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 Young Hollywood TV Movies A-Listers Sign up with facebook or By signing up, I agree to the Terms and to receive emails from POPSUGAR.