During all of your training, you are trying to convince your body to keep going, and you ignore your mind when it thinks it is tired. So why listen now? How do you know when it is time to take a step back?

With 47 marathons, four 50-milers, three 50K races and countless miles under my belt, people always ask me, “What do you think about for that long?” Most days, I don’t have an answer.

How cold can you run outside and what things do you need to take into consideration? When should you turn to a treadmill? Keep the following in mind.