The five-time Ballon d'Or winner is Madrid's record goalscorer, while his honors include five Champions League titles, three Premier League trophies, Euro 2016 glory, two Serie A crowns and as many LaLiga triumphs to go with numerous other silverware.
But when it comes to watching television, Ronaldo revealed his love for combat sports.
"Playing football is my passion, but I prefer watching other sports on TV," Ronaldo told boxing star Gennady Golovkin in a DAZN documentary titled 'Parallel Worlds'.
"Between watching a football match or a boxing or UFC fight, I choose boxing or UFC."
Ronaldo, who has met UFC star Conor McGregor previously, added: "When I was at Manchester United, a coach boxed with me.
"I think practicing boxing is useful for football because it sharpens your senses and you learn to move."
Aged 35, Ronaldo has showed no signs of slowing down in 2020.
Ronaldo celebrated his 100th Juventus appearance with a brace in Sunday's 3-1 Serie A win over Genoa.
Not only was Ronaldo making his 100th Juve appearance, he also became the first player to reach 400 wins across Europe's top five leagues this century.
Additionally, Ronaldo – who has netted 77 times since joining Juve in 2018 – reached 31 goals for the calendar year, making him the third Bianconeri player to reach this milestone in the top flight, and the first since Omar Sivori in 1961.
"Last summer, I had a chat with [heavyweight champion] Anthony Joshua," Ronaldo, who has 10 Serie A goals in seven appearances this term and 14 across all competitions, said.
"At 33 you start to think your legs are going. I want to stay in sport, in football. People will look at me and say: 'Cristiano was an incredible player but now he's slow'. I don't want that.
"You can change a lot about your body, but the problem isn't that. It's depends on your mindset, your motivation and your experience, which I think is the most complex thing.
"In sport, you can gain maturity. Look at [Roger] Federer in tennis; he's 37 or 38 years old and he's still at his peak, and there are some in boxing too."