If you want to be in shape, skip the 10K training and sprint — but don't jog — to the nearest weight room.
I like running when I actually get into it but more and more research says that you could be losing weight due to running (great) but you won't burn body fat.
Popsugar.com has easily the best explanation and while you shouldn't STOP running maybe this will be the kick in the butt to get you to find a new way to approach your weight loss.
You're Burning Less Than You Think
You just got back from a run, you're covered in sweat, and you're convinced you burned over 500 calories. But did you really? A 150-pound woman will burn 495 calories running for 45 minutes at a 10-minute-per-mile pace. If you didn't run for that long or that fast, then you're not burning as many calories as you thought. It's best to track your workout just to be sure, using a heart rate monitor or one of these cheap running apps on your phone.