6 Reasons You’re Spotting After Exercise When You’re Not Expecting Your Period

Vaginal bleeding after a workout can be concerning. If it happens more than once or twice, it could be a sign of an underlying problem that you should speak with your healthcare provider about.

“Spotting after exercise isn’t that common, and it usually does indicate that something is a little abnormal with a woman’s hormones or anatomically,” says Jennifer Wu, MD, an ob-gyn at Lenox Hill Hospital at Northwell Health in New York City.

Here, Dr. Wu shares some of the most likely reasons exercise can cause spotting and what you can do about it. Plus, learn other possible culprits behind bloody discharge after exercise that may not necessarily be related to your workout.

1. You Have a Polyp

Uterine polyps are small, noncancerous growths that can lead to heavy or irregular periods and spotting between periods. They typically remain within the uterus, but sometimes they can extend into the opening of the cervix or the vagina.

Spotting from a polyp can happen anytime, but it may be more likely after exercise or sexual activity because polyps can bleed from irritation or contact, Wu explains.

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2. You Have Very Low Body Fat

While specific numbers vary, a very low body fat percentage may cause your period to become irregular, potentially leading to spotting during exercise or at other times. (In some cases, low body fat can also cause your period to stop altogether, which is referred to as exercise-induced amenorrhea.)

“This typically applies to extreme athletes with a lot of muscle mass,” Wu says. “It’s more common during training season, and then periods may become more normalized during the offseason.”

In some cases, exercise-induced period loss can also happen from not eating enough.

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3. Your Clothing Is Causing Chafing

Sometimes what appears to be spotting could be from chafing during your workout. This might be the case if you see bright red spotting after exercise. That color is more likely to be caused by an injury as opposed to dark red or brown spotting, which is more likely to come from inside your body.

“Irritating clothing could cause bleeding externally or at the entry of the vagina,” Wu says.

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Try changing up your workout clothes. Stretchy, form-fitting bottoms work well for higher-intensity activities like running or biking; looser ones can be good for walking, gentle yoga, or strength training.

And consider incorporating anti-chafing products into your routine.

4. Your Hormones Are Shifting

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Talk to your doctor about your spotting plus any other symptoms you might be experiencing, your reproductive health history, and your current birth control use. There might be another type of birth control or hormone therapy that could result in less bleeding.

Your doctor might also suggest testing to rule out pregnancy or other underlying health conditions.

5. You Have an Infection

Urinary tract and sexually transmitted infections can sometimes cause spotting or blood in your urine that you might notice after exercise or at other times.

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You’ll likely need antibiotics if an infection is the cause of your bleeding. Talk to your doctor about your symptoms. They’ll likely do a blood or urine test to determine the underlying cause.

6. You Have an Underlying Medical Condition

Spotting can have a number of other causes. But they’re not typically linked to exercise specifically, so breakthrough bleeding can happen at any time, Wu points out.

• Medical conditions, like bleeding disorders, thyroid problems, adenomyosis, uterine fibroids, cervicitis, or endometrial hyperplasia
• Cervical or endometrial biopsies

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There may not be a simple or quick fix to some of these underlying health concerns. If you and your doctor suspect a more serious condition, you’ll likely need to undergo tests to figure out the cause of your spotting. Then, together, you can determine the best course of treatment.

• Between-period bleeding that occurs more than once or twice isn’t typical and may be a sign of an underlying problem.
• If spotting persists for more than two or three months, consult your physician.
• See a doctor if your spotting after exercise is accompanied by new or worsening pain.