Dwayne 'The Rock' Johnson says he pees in water bottles during his workouts because his gym doesn't have a toilet

• Dwayne "The Rock" Johnson once showed his followers a bottle of his pee in his workout room in 2017.
• On Friday he said he still does because he drinks so much water.

Dwayne "The Rock" Johnson fans still talk about that time, in 2017, when the actor posted a video that included his own urine in a bottle and said that he pees in water bottles during his workouts.

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More than four years on, Johnson has explained, during an interview with Esquire, why he reuses empty water bottles as portable urinals.

"It's not a water bottle that I've actually purchased solely for water that you wash and clean when you're done using it. These are just bottles that I'm no longer using," Johnson said. "Usually the gyms that I work out in don't have a bathroom because they're the iron paradise. There's no bathroom there. They're just hot, sweaty, and dirty."

Johnson added that he usually stays "pretty hydrated" throughout the day, which is why he has to "break out the bottle."

The American Council on Exercise recommends drinking 17 to 20 ounces of water - the equivalent of 2 1/2 glasses - two to three hours before you start exercising, 8 ounces of water 20 to 30 minutes before you start exercising, and 7 to 10 ounces of water - or 1 1/2 glasses - for every 10 to 20 minutes of exercise, regardless of whether the exercise is mild, moderate, or intensive.

Johnson's documented workouts demand a lot of hydration, as one of his most famous workouts involves doing 50 sets.