Despite being at the ripe age of 36, he is shredded like no other footballer.
Now, after a cheeky moment during Portugal's press conference ahead of their Euro 2020 opener against Hungary, we know one way the Juventus star keeps his body insuch good shape.
Ronaldo looked at two glass bottles of Coca-Cola — an official sponsor of the tournament — and decided they didn't belong on the table in front of him.
Meanwhile, Portugal coach Fernando Santos sat next to his captain and elected for his two bottles to remain where they were.
After taking the Coke bottles off the table and placing them out of sight, Ronaldo produced a bottle of water, holding it up and proclaiming to the assembled journalists people should "drink water".
Cristiano Ronaldo's press conference stunt wiped $5.2 billion off the value of Coca-Cola. Photo / Supplied/news.com.au
The move isn't what Coca-Cola had in mind when sponsoring the European Championships, and the company saw $5.6 billion (NZD) wiped off its market value after Ronaldo's stunt.
At the start of the press conference, The Athletic reports Coca-Cola's shares were worth $78.84 each but by the end, they'd dropped to $77.56 — a 1.6 per cent dip in value that was worth a total of $5.6 billion.
Coca-Cola issued a statement in response to Ronaldo's antics, saying "everyone is entitled to their drink preferences" and everyone has different "tastes and needs".
A spokesperson added: "Players are offered water, alongside Coca-Cola and Coca-Cola Zero Sugar, on arrival at our press conferences."
Cristiano Ronaldo in action for Portugal. Photo / AP
The move worked out well for Ronaldo, who became the all-time top scorer in the history of the European Championship with a late penalty in Portugal's opening Euro 2020 game against Hungary in Budapest.
Ronaldo's strike, which put the titleholders 2-0 up with three minutes left, was his 10th in the European Championship finals, spread across five tournaments going back to 2004.
Ronaldo then added another goal in stoppage time, his 11th Euros strike securing a 3-0 win in the Group F match.
Ronaldo beats the previous mark of nine set by France's Michel Platini. All of Platini's goals came in France's triumphant Euro campaign on home soil in 1984.
In contrast Ronaldo scored twice at Euro 2004 when Portugal lost in the final to Greece as hosts, then added one in 2008, three in 2012 and three more when the Selecao won the trophy in 2016.
He now has 106 goals altogether for his country, leaving him just three goals away from equalling the all-time international scoring record of 109 held by Iran's Ali Daei.
"It was essential to start on the right foot in order to gain confidence," Ronaldo said after beating Hungary. "Now, we have to continue and win the next game.
"It was a difficult game, against an opponent who defended very well during 90 minutes, but we scored three goals, and I am very grateful to the team for helping me to score two goals."
Ronaldo has a famously strict diet and avoids sugary foods, eating clean up to six times a day to maintain his incredible physique while he ages.
While still at Real Madrid, the club doctor said he had the body of a player 10 years younger and could continue playing at the top level into his 40s.
Fish is a major part of Ronaldo's diet and he regards chicken as "magical" due to its high protein and low fat content.
For breakfast the football superstar will eat ham and cheese and low-fat yoghurt. If he doesn't have it for brekkie, the former Manchester United star will wolf down avocado toast for snacks during the day.
Lunch No. 1 could consist of chicken and salad, while No. 2 might be fish — maybe tuna with salad, eggs and olives.
Dinner will see Ronaldo fill his boots with meat or fish, sometimes breaking them up in two separate sittings. Steak, swordfish or the Lisbon speciality of Bacalhau a la Brasa — a mixture of braised cod, onions, thinly sliced potatoes and scrambled eggs — should see him through until bedtime.
Once tucked up, Ronaldo will ensure he has eight hours of sleep each night. "Proper sleep is really important for getting the most out of training," the Portuguese player has said previously.
"I go to bed early and get up early, especially before matches. Sleep helps muscles recover which is really important."
