Actor Varun Dhawan has thrown a fitness challenge to those who want a flat tummy. Dhawan, who has started shooting for Street Dancer 3, on Friday night uploaded a video in which he was seen doing a plank exercise (front hold). He said: “I have a big shoot coming up… So what we are doing… this is a plank challenge going on every night.” The actor captioned the clip: “Do the ‘#SD3 The Plank Challenge’. It’s open to everyone, so I actually don’t care if any one famous does this or not. I want people who just want a flat tummy to try this everyday to do around 1 minute or more and post it or tag me.” (IANS)