Portuguese football star Cristiano Ronaldo let loose his silly side recently as he challenged his son, Cristiano Ronaldo Junior, to take a plunge into a cold pool after showing off his fitness by performing the stunt himself.

The Al Nassr striker recently posted a video on his Instagram in which he can be seen entering a pool with negative temperature, surrounded by snow, after taking a steam in a sauna.

“Guys look at this experiment, freezing!” he said in the video as he entered the pool.

“-20! And now what I have in my front,” the 39-year-old five-time Ballon d’Or award winner said while pointing at the pool, as his 14-year-old son watched his father perform the stunt.

While being fully covered in freezing cold water, the former Manchester United, Real Madrid and Juventus star challenged his son to take dip as well.

The fun video was filmed by Ronaldo’s partner Georgina Rodriguez could also be heard in the video saying words of encouragement.

Ronaldo’s challenge for his son comes as the football star enjoys Christmas holidays with his family in Finland.

Ronaldo, who plays for the Saudi football club Al Nassr, is praised globally for his fitness and is often seen taking on fitness challenges both on and off pitch.