Why Do I Taste Blood When I Run? Discover 4 Possible Reasons

Intense exercise can take a heavy toll on you physically and mentally. Your muscles are on fire, and you can hardly move your arms and legs.

Your chest beats a million beats per second, and your stomach feels like it’s doing somersaults.

These are all common signs of a heavy workout. Yet, it’s the metallic taste you may sometimes experience that’s probably gotten you baffled.

Many people come to us with this question: why do I taste blood when I run?

Because this isn’t what you call a common occurrence, we decided to find out why this happens with certain people and not with others.

We’ll also talk about whether it should be a cause for concern. So, let’s get started.

Why Do I Taste Blood When I Run?

Why Do I Taste Blood When I Run: Young woman running on mountain peak

When you continuously subject your body to such high intensities, certain things in your body will get compromised.

If you continue to do so without pause or give your body the proper recovery time, it may have severe repercussions in the long run.

Having that metallic taste is your body’s way of letting you know that you’re doing way more than it can handle.

It’s a signal to slow down a bit, breathe deeply through your nose, and lower the intensity of your workout.

Why Do I Taste Blood When I Run or exercise? Case point shouldn’t be a regular occurrence.

The good news is it’s not a sign of any physical problems. Nor does it indicate you’re doing anything wrong.

It just means you’re doing loads of endurance training or distance running without taking a breather every once in a while. However, it’s temporary and goes away on its own.

Why Do I Taste Blood When I Run? Possible Reasons

While physicians aren’t exactly sure why this happens, they do have a few theories.

Take a look.

Nasal Airways

Imagine running up a flight of stairs or running long distances without giving yourself enough time to acclimate.

What happens is after a few short minutes, your lungs will be starving for oxygen.

So, to take in as much oxygen as possible, you start breathing through your mouth. This solves the lack-of-oxygen problem.

At the same time, it causes a whole new problem somewhere else: inflammation of the mucosal linings of your nasal airways.

When these linings are irritated and inflamed, especially if you’re in a cold environment, it can lead to minor tears, and they start to bleed in tiny amounts.

Then, small blood droplets fall back into your throat and mix with your saliva. Accordingly, they hit your taste buds, and you taste blood.

The Heart and Lungs

When you exercise continuously without any rest or recovery time, a lot of pressure builds up in your airways, especially in dry or cold environments.

Pressure also builds up on your heart. For example, in some types of interval training, such as traditional HIIT, your heart rate can reach extreme levels of up to 95% of its maximum capacity.

All this excess load puts immense pressure on the air sacs, or alveoli, in the lungs. As a result of this physiological stress, small amounts of red blood cells enter the alveoli.

How does this happen?

Let’s start with a simple biology lesson. The alveoli are surrounded by a network of blood capillaries or thin-walled, fragile veins.

Their thin walls allow for the interchanging of oxygen and carbon dioxide.

When you push yourself past your limit or threshold, your lungs fill up with high air pressure levels.

The pressure becomes so great that it forces these thin capillaries to burst open and release tiny droplets of blood into your airways.

Blood comprises red blood cells containing the iron-rich protein known as hemoglobin.

This iron-rich protein is known for its metallic taste. Hence, your mouth fills up with the taste of blood.

Beginner Fitness Levels

If you’re just starting to train for intense workouts or long-distance runs, you could be more prone to tasting blood.

It tends to occur more frequently in anyone who suddenly dials up the intensity of their training.

Then, the more established your cardiopulmonary system is, the less often it happens.

That is, until they boost the intensity of a workout or two to extremely high levels, even more than what they’re trained for.

Dental Fillings

Oral hygiene can be another culprit. If you have loose or worn-out delta fillings, they can produce that metallic taste when you run and work out.

We usually grind our teeth to push through high-intensity training sessions and long-distance runs. As a result, you chip away micro-sized pieces of your filling, which have a metallic taste.

Who Is More Susceptible to Tasting Blood When Running?

Running man listen music on his device against the blue sky. Silhouette of running man on sunset fiery background

Experiencing that metallic taste in your mouth during your workout or afterward has to do more with the intensity of the workout.

It also depends on the duration as well as specific environmental conditions.

So, someone doing low-intensity weight training in cold weather probably wouldn’t taste any blood in their mouths.

On the other hand, a distance runner or endurance athlete will likely be exercising continuously for long periods of time.

Pushing past their thresholds and not having time to recover causes the metallic taste.

We also mentioned that people who are just starting to increase the intensity of their workouts are more susceptible.

This is particularly true if they start training too much too fast.

How Can You Avoid Tasting Blood When Running?

Tasting blood during an intense workout may not be a sign that something is wrong with you. Still, it’s not a good thing either.

Here are a few ways to avoid it.

Pace Your Workouts

Working or running at high-intensity levels every time you exercise isn’t the way to go. You’ll burn out extremely quickly, which will do more harm than good.

Keep in mind that you won’t get that metallic taste if you’re running at comfortable levels. Truth be told, tasting blood simply means you’re overworking your body.

This is why it’s important to pace yourself. Intense workouts and long-distance runs shouldn’t exceed two or three times a week.

If your goal is to run a marathon or 10K, try to schedule 24 hours of recovery and rest between each HIIT session.

Giving yourself time to recover is actually when your body heals itself, builds muscles, and increases its endurance.

athlete drinking water

Stay Hydrated

Drinking plenty of water keeps your mouth hydrated. A dry mouth can increase the metallic taste.

In addition, staying hydrated keeps your mucous linings moist and healthy. Thus, they become better at handling extreme dry and cold weather.

Maintain Good Oral Hygiene

Besides preventing dry mouth by drinking lots of water, you also need to maintain your oral hygiene. Remember to brush 2 – 3 times a day.

Additionally, flossing and tongue-scraping should be part of your daily oral care plan.

Following these guidelines won’t just prevent the metallic taste, it’ll keep your mouth bacteria-free and healthy as well.

When Should You Seek Medical Care?

The only time you should start to worry is if you start getting a metallic taste during every workout or the taste is becoming more intense.

Keep an eye on other symptoms as well. For example, if you experience shortness of breath or chest pains, that could be a sign of a more severe condition.

Speak with your physician and get it checked out as soon as possible. Chances are it could be an underlying autoimmune issue, cardiac problems, or high blood pressure.

A Final Note On Why Do I Taste Blood When I Run

Knowing the answer to the common question ‘why do I taste blood when I run?’ can help you modify the intensity of your runs.

As long as there aren’t other symptoms, then the occasional metallic taste is nothing to worry about.

The best thing to do is have a well-balanced training program that allows you to work at your own pace. Also, maintain good oral hygiene and drink lots of water to stay hydrated.