I'm training for a half marathon and have noticed that when I bump up my milage I end up with a sore throat the next day. The last time this happened a few weeks ago, I ended up with a cold overnight that lasted a week. Does anyone else have this happen during their training?
You are probably overtraining. Without knowing all your symptoms, previous running history, and current running plan, it hard to say for sure. But a sore throat and a cold after long runs tells me that your immune system is suppressed from the stress your body is feeling from the training. What is your current mileage? When is your 1/2 marathon?
What's your nutrition and hydration levels? Running is not as natural an activity for the body as walking is. We are designed to walk, not run. So the body needs to adapt both biomechanically and physiologically or else it rejects the whole idea. Immune system compromise is nothing to mess with. Your body is screaming out for a rest and a return to some kind of homeostasis.
Let me know more about those questions above and we'll go from there.