The American actor is perhaps best known for playing Boone Carlyle in TV drama Lost and Damon Salvatore in supernatural show The Vampire Diaries.

And when it comes to maintaining his youthful good looks, the 38-year-old credits his healthy appearance to regular sessions in his at-home hyperbaric chamber, a technology which is typically used by medical experts to treat decompression sickness.

"It's a chamber that you zip yourself into and it's connected to an oxygen concentrator," said Ian during an appearance on Jimmy Kimmel Live! on Monday night (06Mar17) of the device.

"It's looks like you're zipping yourself into a big torpedo. But you get into this thing and there's 98 per cent oxygen pumping into it, it's basically 10 litres more per minute of oxygen than you'd ever get in the atmosphere, so it's pressure cooking oxygen into your largest organ, your epidermis, and you also have a mask."

Ian added the hyperbaric chamber he owns is a "little smaller" than the machine famously used by the late Michael Jackson, who used the Sechrist 2500B chamber in 1984 in the hope of the added oxygen aiding the speedier recovery of damaged tissue, after being burned while filming a Pepsi advertisement.

And when it comes to his own use, Ian describes the impact of using the device as giving him a "high".

"You're so high on oxygen. You're just buzzing and zipping around," he explained.

In fact, the star is such a big fan of the chamber that he introduced the technology to his wife Nikki Reed, who he married in 2015, on one of their first dates together.

"I put Nikki in it on our second date, it's great. All I'm saying is 10 months to the day, we were married. It speeds everything up," he laughed.