Jason Walsh is the fitness expert who helped Australian actress Teresa Palmer get in shape for her starring role in the action-packed film, I Am Number Four. And other equally well-toned stars, including Kate Beckinsale, Ben Affleck, Emile Hirsh, Natalie Portman and Jessica Biel, have benefitted from Jason Walsh's skills as a physical trainer too.

We spoke to Jason give us his tips for getting into the best shape of our lives.