The footballer recently celebrated his milestone birthday and Joao Aroso – who was his fitness coach at Sporting Lisbon and reunited with him as assistant coach at Portugal between 2010 and 2015 – believes it isn’t just the sportman’s level of fitness that has helped him continue to keep his form on the pitch.

Joao told FourFourTwo magazine: “While it’s important to be in good physical condition – and we all knew Cristiano took immense care of himself, always has, ever since he was 18 when I first worked with him at Sporting – the type of care has changed over the years.

“Back then, it was all about training, training, always wanting to train as must as possible.

“[At Portugal] it was still a lot of training, but there was much more focus on recovery as well.

“Cristiano paid great attention to recovery, nutrition, anything that could make him the best athlete.

“But there’s something very important something that has been crucial for him to reach 40 years of age and be at this level, continuing to play at the top – and that’s his mentality.

“It’s his drive, his passion to want to keep playing.

“Physical abilities help, of course, but a lot of it comes down to the mental side – the joy he gets from that, the pleasure he finds in training, playing and breaking records.

“That’s what keeps the engine running.”

The Al Nassr player is always looking for ways to improve his health and fitness.

Jose Carlos Noronha, director of the Portuguese FA’s health and performance unit, told the publication: “He’s very inquisitive – he’d ask me if there were any new scientific articles he could read about nutrition or related topics.

“Cristiano has a unique physical build, like one of those cars that can rack up millions of miles and never break down.

“He does everything to maintain the highest levels of physical and mental fitness, from his diet to sleep and physical preparation.”