Ronaldo is currently away with the Portuguese national team
Ronaldo swears by cryotherapy, which he has used regularly since 2013 while playing for Real Madrid. It is said to aid recovery between matches, quicken the healing of injuries and decrease fatigue, as well as aiding sleep.
Users stand in the chamber for up to five minutes as it emits liquid nitrogen outside the main cylinder to cool down the chamber to temperatures as low as -200C. The cold air shocks the body and stimulates its recovery. Gareth Bale is another player who has regularly used cryotherapy, as did Leicester City players during their title-winning campaign.
The 36-year-old, who signed a two-year contract at Old Trafford with the option of a one-year extension, has made a good start to life back at the club with five goals in seven appearances. However his last match ended in frustration as he was left on the bench by manager Ole Gunnar Solskjaer, and could not prevent United from letting their lead slip against Everton.
Ronaldo is currently away with the Portuguese national team, who play 2022 World Cup hosts Qatar in a friendly on Saturday night before taking on Luxembourg in a qualifier on Tuesday.