Why do I sometimes taste blood when I exercise strenuously?

November 3, 2006 7:24 AM

Why do I sometimes taste blood when strenuously exercising?

Last night, after a long hiatus, I played a few hours of basketball at the gym. After a few trips sprinting up and down the court, I tasted blood. This has happened before, I can recall it when playing football when it's chilly.

What's going on? I take this as a sign that I'm out of shape and was pushing too hard, but what's really happening? Blood leaking from my sinuses? Are pulmonary capillaries breaking?

posted by cramer to Health & Fitness (11 answers total)

I get this when it's cold out or I've been sick.. pretty sure it's analagous to mini bloody noses. One time I asked and was told that if I get bloody noses, that'd do it.
posted by shownomercy at 7:27 AM on November 3, 2006

I'm pretty sure this has been asked before. Can't find the thread right now though.
posted by ClarissaWAM at 7:57 AM on November 3, 2006

I wonder if the cold air could be drying out your sinuses, leading to trace amounts of blood from irritation.

Another thought: Do you have red, puffy gums? There might be blood in your mouth from inflamed gums.

Do you drink enough fluid while working out? Perhaps that might help.

If this is an ongoing problem, I'd check in with a doctor.
posted by Sully6 at 7:59 AM on November 3, 2006

i've gotten the mini-bloody nose explanation as well. Sometimes I smell it if I have a particularly awesome sneeze, too. Then again, sometimes it smells like a motor, so I could just be fucked up.
posted by danb at 8:02 AM on November 3, 2006

I think I know what you're talking about, but I'm not sure that it's blood that you're tasting. I typically taste this when I'm sprinting for a while and well into my anaerobic zone. There's a related change in the viscosity of my saliva, it becomes very thick. I've assumed that the taste is iron, but not blood, and that it's linked to those changes in saliva. (My saliva never shows visible traces of blood in these instances.)
posted by OmieWise at 8:03 AM on November 3, 2006

This pdf study tracks many of the changes in saliva during anaerobic exercise, but makes no mention of elevated iron.

Someone on this biking forum claims that it is blood from burst capillaries, but with no evidence to support it.
posted by OmieWise at 8:08 AM on November 3, 2006

I get the thick saliva thing but not the blood.

I think the viscosity of the saliva is actually because you're mouth breathing constantly when you go anaerobic (gasping), which evaporates saliva very quickly, and if you are not constantly hydrating, you get a bit dehydrated as well. I hydrate pretty well (I wear a camelback while cycling, and use it) but in cold, dry weather particularly it's hard to drink enough.

If the OP is getting dehydrated while exercising, that might well cause the sinuses to dry out and trigger a minor bleed.
posted by unSane at 8:09 AM on November 3, 2006

I first noticed this not long after I had my tonsils and adenoids removed when I was in the sixth grade. I assumed then that it was those wounds opening up when I worked out in cold air. And since I never questioned this assumption, I just realized that I still accept that explanation, even though it makes no sense almost 20 years later for my throat to bleed for that reason.
posted by palegirl at 8:13 AM on November 3, 2006

Response by poster: The taste is often accompanied by a thickening of saliva, and water does help.

I found this in the archives, is that what you're thinking of ClarissaWAM?

There's also this abstract, but I can't log-in for the full article.
posted by cramer at 8:36 AM on November 3, 2006

Could it be a metallic taste in your mouth that comes with a surge of adrenaline?
posted by mikeh at 1:50 PM on November 3, 2006

Can't find links right now, but I'm pretty sure it's actually a result of the alveoli in your lungs being overtaxed; in their hurry to transfer CO2 back out of your blood stream, some of the blood cells themselves are pushed through the alveolar walls, which you then breathe out as an aerosol and taste on your tongue.

It's worse when you're pushing your metabolic limits (and, incidentally, at high altitudes), so getting into better shape would probably largely fix the problem. But, in and of itself, it's probably nothing serious.
posted by thomascrown at 2:06 PM on November 4, 2006