Dwayne Johnson has a strange workout habit: peeing in water bottles at the gym.

Earlier this week, he told Esquire that he has a habit of using a bottle as his bathroom while he’s training—mostly using old plastic water bottles.

“Well, yeah, the headline is actually true; I do pee in my water bottles, but let me give context to that,” he said regarding a recent, viral headline from Men’s Health. “‘Cause everyone’s leaning in now to what this means. It’s not a water bottle that I’ve actually purchased solely for water that you wash and you clean when you’re done using it.”

He continued, “These are just bottles that I’m no longer using. And usually the gyms that I work out in don’t have a bathroom…There’s no bathroom there, it’s just hot, sweaty, and dirty. I usually stay pretty hydrated; I need to go to the bathroom a lot. Not a lot, but probably a couple of times during every workout I have to go to the bathroom. So, break out the bottle.”

According to Consequence of Film, fans first learned of this workout quirk in an Instagram video in 2017, when he saw that a bottle of urine could be seen in a clip he posted. “I just realized you all just saw my big bottle of pee. Look, I go hardcore when I train. I don’t have time to go to the bathroom. I find a bottle, I pee in it, and I keep training like a beast.”

Johnson’s latest film, Netflix’s Red Notice, also stars Gal Gadot and Ryan Reynolds and is now streaming.