Remember last season on This Is Us, one of the most iconic moments was when Jack did push ups with his prepubescent son his back? Then the older actors shared videos of them doing the same thing with their castmates on their backs? Well yesterday, Justin Hartley shared a video of himself holding several heavy weights on his back and you have to wonder if he is prepping for another round of emotional push ups on the show? Who do you think he would have his back?