United Kingdom, Dec. 10 -- John Cena can "operate" without sleep for 40 hours straight.

The Hollywood star - who will wrestle his last ever WWE match on Saturday (13.12.25) at Saturday Night's Main Event - has opened up about his hectic schedule this year, which has seen him travel back and forth around the world to keep up with his wrestling and film commitments.

Asked how he finds time to sleep, he told the Insight with Chris Van Vliet podcast: "I get rest. I used to - it's a thing from the Right Now [music] video where I have a sign that says 'Sleep is not mandatory'. I should cross out the 'not'.

"Sleep is mandatory, and I fashion my days around that.

"So, when we have, say, Budapest to Indy, Indy to Budapest, and I say I'm gonna ...