Michael Phelps is widely considered the greatest swimmer of all time — but even he has his limits.
On Wednesday, popular rapper Young Thug posed a ridiculous hypothetical about the super-human abilities of the former Olympian.
"I'm talking with my roommate and we're wondering if you could swim 100 miles from the middle of the ocean back to shore - @MichaelPhelps," he wrote on Twitter.
"An elite swimmer can swim a mile in a pool in about 16 minutes. Taking into account the rough conditions of the ocean, the lack of food or clean water, and the insane about of time it would take, no I don't think even the world's best swimmer would survive," one wrote in response.
Several marathon swimmers have eclipsed the 100-mile mark, but ultra-distance swimming was never Phelps' focal point.
Phelps holds the all-time record for Olympic medals with 28 — 23 of which are gold. Each of his medals came in either 100-meter, 200-meter or 400-meter events.