What to Know About Swimming During Your Period

Medically Reviewed by Melinda Ratini, MS, DO on August 15, 2023
4 min read

You don’t have to change any of your regular activities when you have your period. That includes exercise and swimming. There are many misconceptions about swimming during your period. 

It’s messy. You can swim when you have your period. You just need to wear a tampon or menstrual cup to catch the flow. Competitive swimmers have participated in big races during their periods.

It isn’t safe. While a shark’s sense of smell is powerful, there’s no evidence that menstrual blood increases your risk of being attacked by sharks. More than 80% of recorded shark bites happened to men. 

It’s unhygienic. It’s always best to wear a tampon or menstrual cup when swimming. It’s very unlikely that there will be leakage, but swimming pools are chlorinated and use a filtration system.

Cramps will be worse. You may not feel like swimming if you have painful period cramps, but exercise may actually help improve your period pain. 

One study of 70 women with regular period cramps (primary dysmenorrhea) found that those who exercised regularly over 4 weeks had improved levels of pain.

Researchers found that 30 minutes of aerobic exercise three times a week helped significantly improve the severity of period cramps after 8 weeks. This effect wasn’t seen after just 4 weeks of exercise.

Talk to your doctor if your menstrual cramps are very painful. It may be due to a condition such as:

  • Adenomyosis. This is a condition in which the lining of your uterus grows into your uterus muscle. It causes your uterus to be enlarged.
  • Cervical stenosis. This is when the opening to your uterus (cervix) is narrow. 
  • Endometriosis. In this condition, the tissue lining your uterus (endometrium) grows outside your uterus. 
  • Fibroids. These are growths on the inside or outside of your uterus.

You may have heard that your period stops when you’re in the water because of the water pressure. That’s not true. The water pressure may slow the flow, but your period will still continue. That’s why you should use a tampon or menstrual cup when you’re going swimming.

Don’t use pads in water. You may prefer to use pads during your period, but they’re not meant for use in water. Pads will just absorb the water around you. Using one in water makes it ineffective and messy.

Tampons. Tampons are usually made of cotton, rayon, or a combination of the two fibers. You can use tampons when swimming. They might absorb some water but this will only make it a bit wet. Change the tampon shortly after swimming.

Tampons are linked to toxic shock syndrome. This is a rare but serious complication. It may be caused by toxins produced by Staphylococcus aureus – staph – bacteria or group A streptococcus – strep – bacteria.

Toxic shock syndrome can affect anyone. It’s been associated with:

Symptoms and signs of toxic shock syndrome include:

To lower your risk of toxic show syndrome, follow these recommendations:

  • Use the lowest absorbency tampon needed.
  • Wash your hands before and after using a tampon. 
  • Change the tampon every 4 to 8 hours, and throw used ones away. 
  • Only use tampons when you have your period. 
  • Call your doctor if you have pain or unexpected symptoms when inserting or wearing a tampon, and stop using tampons if you have an allergic reaction. 
  • Reusable tampons may have additional risks of infection. 

Menstrual cups. A menstrual cup is usually made of rubber or silicone. It’s a flexible cup that’s placed inside your vagina to collect blood during your period. It doesn’t absorb your menstrual flow so you’ll need to remove it, empty it, and wash it.  

Menstrual cups are safe to use, with a possible lower risk of infection compared to pads and tampons. As some menstrual cups are reusable, there’s lower costs and less waste compared to tampons and pads.

Period-friendly swimwear. Period swimwear or underwear is absorbable and reusable. It’s similar to a pad but it’s built into the lining of the swimwear or underwear. They’re made with many thin layers of material which traps the blood. Depending on the type you choose and the amount of your flow, these period swimwear or underwear may hold as much menstrual blood as one to two tampons.

You should change and clean your period swimwear or underwear at least every 12 hours. Read the instructions before you wash it. 

Period swimwear or underwear may seem pricey at first, but it can end up being cheaper than having to buy tampons or pads every month.