Kylian Mbappé is one of the most coveted footballers in the world. The most valuable French player and forward worldwide, the 21-year-old Parisian is famous for his extreme speed, strength, and finishing.

Football and fitness nuts have spent countless hours wondering how the PSG star manages to maintain his incredible speed game after game. Now, a recent Instagram post by the man himself may shed some light on how he stays razor-sharp between matches.

Already known for being a cool operator, Mbappé posted a snap of him chilling in a cryotherapy chamber – at a crazy -146°C. We don’t know about you, but we’re not sure how he’s keeping such a straight face.

If you haven’t heard of it before, cryotherapy, also known as cold therapy, is a somewhat controversial treatment where patients are exposed to extremely cold air for a short period of time in order to combat fatigue after exercise. It’s basically the modern version of taking an ice bath.

Proponents of cryotherapy suggest that it helps with recovery and can provide relief for muscle pain, sprains and swelling. It’s not a cheap endeavour, either – but that’s not a problem for Mbappé, who’s worth about $25 million.

However, the science isn’t settled on whole body cryotherapy, and it can also come with some serious risks. NFL player Antonio Brown gave himself frostbite last year after wearing inappropriate footwear in a cryotherapy chamber, The Guardian reported.

Our Kylian is clearly keen to take his chances, and if his performances on the pitch are anything to go by – not to mention his extreme speed – it’s clearly having a positive effect.