This is going to sound odd, but I keep thinking I should be 'suffering' after a run and I never am. Does this mean I'm not pushing myself hard enough? At the most I have a slightly sore abdomen, nothing serious at all, just letting me know I've worked my core, and I may feel more tired than usual. But I never have sore legs, even after the 25 min week 7 runs. Is this a good sign or not?