The Icky Fall Effect

So today I am day # 2 into my first cold of the fall season. I thought I had been doing well with all of my Purell, Multi- Vitamin and 1000 mg of Vitamin C. Well I guess I was wrong. So now along with the cold I'm stuck with the dilemma (run 8 miles tonight as planned or calm it down and do the ever happy 6 miles?). When as a runner are you able to decide that with training you should just leave it to the body? So I guess I will do what Jaime ( my running buddy) suggests and do the 6 and see how my body feels. Wish me luck !!!