Turning around early on a run when something hurts just plain stinks. You feel like a failure, you question your toughness and the running you did do feels pointless. But there are times where you get out on a run and something feels bad or wrong and you need to flip around. A funky ankle, a tight IT-band, a sore achilles, a balky knee. Whatever it is, continuing to run on it probably isn't going to make it better. But most people continue to run when they feel weird pains, thinking "I should just keep going" or "it's not that bad" or "if I can't be tough through this little issue how am I going to be tough in my next race?" Wrong. You need to flip around, go back and call it a day and then figure out what you're going to do. Do you need to simply take a day or two off from running? Can you afford to go see a medical professional and get an opinion on what is wrong? Should you be cross training and if so, what modality is best? You've got lots to think about, but what you don't want to do is continue to run on something that hurts because it's just not worth it. By flipping on a run the first day something hurts, you greatly increase your chance of healing and getting back to running quickly; if you hobble through a run when something is obviously wrong, you run the risk of missing weeks (months?) of running rather than days. I'd argue it takes the same amount of guts to turn around on a run and head back home than it takes to push through the discomfort of your original run. So have the guts to turn around when something hurts.