Doesn't have to be a trick though. As long as some measurable dent in the pile of work is made, that's infinitely more than none at all, right? One way to make this real is for the first few times, to commit to definitely stop after the short interval decided for. So work out for those five minutes and then stop even when feeling like going longer. This way there's no trick involved. It's about removing the pressure to accomplish a significant dent and allow yourself to feel some satisfaction still, as long as there is a positive contribution. Small steps and all that...
