Buzz
Swimming is an excellent, gentle exercise, which is why so many people incorporate it into their regular fitness routines. However, if you stay in the water for long enough, you may notice your bladder seems more active compared to being on dry land. A study revealed that a 110,000-gallon pool contained around 8 gallons of urine. Does submerging yourself in water really intensify the urge to pee?
Turns out, the answer is yes. This phenomenon is called immersion diuresis, a term that describes the body’s increase in urine output when submerged in water. When you're immersed, your blood vessels constrict, redirecting blood to your internal organs. This raises your blood pressure, which boosts activity in your kidneys as the body tries to release fluid to balance the change in your arteries. The result: the need to pee.
Your kidneys can also respond to the increased water pressure, especially when you dive deeper. With this pressure comes higher blood pressure, prompting your kidneys to filter out more fluid.
Cold water increases immersion diuresis, making it more of a concern in natural bodies of water than in heated pools—though spending extended time in a pool can lead to the normal need to urinate. Nerves play a part, too. Many Olympic swimmers have confessed to relieving themselves in the pool.
Peeing when you're under the pressure of an athletic reputation is one thing. Deciding whether to let it go while playing with a pool noodle in a friend's backyard pool is another. If nature calls, should you answer? In open water, it's not a big deal. Many long-distance swimmers do it without hesitation. In a pool, the decision is more complicated. Although urine contains some bacteria, it's usually not enough to cause illness, especially when chlorine is used in the pool. The bigger issue is etiquette. Since it's a bit inconsiderate to force others to swim in a mix of pool water and your bodily waste, it's best to head to the bathroom.
