French swimmer Léon Marchand won gold in the 200-meter individual medley, picking up his fourth gold medal in five days.
Forget Paris' Seine River, turns out the Olympic swimming pools might be filled with some major human liquid-by-product.
A recent report shed light on whether Olympic swimmers empty their bladders while giving it their all in the pool.
The answer might shock you, or it might not.
Do Olympic swimmers pee in the pool?
According to American two-time gold medalist Lilly King — and others — professional swimmers do urinate in the pool.
King, in a recent report by The Wall Street Journal, told all the dirty details.
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"I've probably peed in every single pool I've swam in," King told the newspaper. "That's just how it goes."
Fellow Olympians backed up King's claims, saying they do pee in the pool all the time.
“I always have to pee,” Jake Mitchell, who swam for Team USA in Tokyo, told the Journal, “because I’m so hydrated.”
Swimmers also pointed to the fact that they have to put on their swimsuits at least 20 minutes before a race as a reason for urinating in the pool.
Is it safe to pee in the pool?
Pools are filtered with chemicals, especially chlorine, that protect swimmers from human debris, such as hair, dead skin and urine.
Chlorine is used to prevent and kill algae, as well as protect swimmers from unhealthy compounds and waterborne illnesses, according to CNBC. A balanced swimming pool has chlorine levels between 1.0 – 3.0 parts per million, according to thepoolpassion.com.
Over-chlorination can lead to irritated eyes and skin, while not enough chlorine can expose swimmers to unhealthy compounds in the pool from things like human urine.
The more debris that enter the pool, the more chlorine is needed. Which is why if you have a pool of your own, it is important to monitor the chlorine levels.
In other words, peeing in the pool is not recommended.
