So, I have a confession to make, I have not been doing my speed work, but I jumped back on the bandwagon this last week.
While I was running my 800s, I began to taste iron or a metallic taste, like I had blood in my mouth. I’ve never noticed this before during speed work, so I decided to look into it.
What I discovered was, doctors don’t know why this happens in runners, but it is not uncommon. There are many reasons for it and some hypothesis.
First, is that there could be an infection in your glands that produce saliva. Physical activity and heavy breathing can increase saliva production and then the infection can get into your mouth. Sorry, kinda gross.
Second, is there could be tooth decay.
I am able to rule out those two as possible causes. Let’s see what else is on the list.
Tiny cracks in the lining of your throat and nose can cause this if you are running in cold, dry air. Especially at higher altitude. This is a likely suspect in my case, but there are still more options.
There are research studies that show that intense exercise increases the pressure on the lungs allowing red blood cells to leak into air sacs. This is only temporary and shouldn’t cause concern for runners.
The last possibility is a mild pulmonary edema, which causes fluid to leak into the space between the air sacs and capillaries in your lungs. Gerald Zavorsky, PhD, associate health and sport sciences at the University of Louisville says that this is what happens in most runners. The fluid that is leaked can contain a small amount of blood, which causes the metallic taste.
Pulmonary edema sounds really bad. My understanding (not a doctor) is that what happens is your left ventricle in your heart is not able to pump the blood out of the heart at the same rate as the right ventricle pumps it into the lungs (to pick up oxygen), this causes fluid accumulation in the lungs and is referred to as pulmonary edema. If your only symptom is the taste of metal in your mouth and things return to normal once you have rested, then you are fine but may want to slow the pace a bit and let your body have time to adjust to the new intensity. If you have other symptoms, shortness of breath, swelling of feet or ankles, a change in mental state then you need to consult your doctor.