Chest cold - should I run?

I’ve checked most of the running authorities and medical experts on this topic and get all different answers. One rule of thumb is “don’t run if you have symptoms below the neck.” Another one is “as long as you don’t have a fever, you can run.” The sports doc I know said, “it’s probably just from post-nasal drip. Take an antihistamine and it will probably dry up.” But I don’t have any nasal symptoms at all, so I’m not sure about this. Mostly I’m just going to have to listen to my own body. Would like to hear others’ experiences, though.

Usually colds start in my nose/sinuses and then sometimes move down into the chest. This one started as a deep, productive cough. The phlegm feels like it’s deep in my lungs as opposed to my brochial tubes, but who knows. My worry is that if I “over-do it” now, it will turn into a chronic brochitis, which I’ve had problems with before. But I’m in the middle of training for a marathon and supposed to do a very long run tomorrow. I hate to lose my fitness right now. I’m signed up for a half-marathon in a few weeks, and the marathon is in June. I’ve had two physicians - runners themselves - say that I should go for it, as long as I don’t have a fever. I only feel mildly ill - no achiness or fatigue - but just have this rattle when I exhale deeply.

What experiences do others have?

I’m in the exact same position as you. I have a ten mile run tomorrow and a chest cold, and I’ve been going back and forth about whether I’ll make the run. I’m not an experienced enough runner to know what’s best for me. I first noticed symptoms of my cold on a five mile run earlier in the week; when I was breathing deeply, I felt pain in my chest, which I knew had nothing to do with being winded. It developed into not too terrible of a chest cold, but it was kind of painful breathing deeply/ talking/ swallowing for a few days.

I did another five mile run yesterday, and it made my throat hurt, but the run was otherwise pretty good. I am leaning more towards making the run tomorrow, but that’s going to depend quite a bit on how much my throat hurts when that alarm clock goes off at 7!