Cristiano Ronaldo's four-year-old son powers through a workout as they perform sit-ups

Cristiano Ronaldo has some competition - and it's not just from opponents on the football field.

The Real Madrid winger was surpassed in speed by his four-year-old son Cristiano Jr when they performed a workout routine together.

In a heartwarming video clip, the 30-year-old conceded to his mini-me who quickly completed a set of sit-ups, proclaiming: 'You're the champion!'

Real fit! Real Madrid star Cristiano Ronaldo performed sit-ups with his son Cristiano Jr in a heartwarming video cip

Cristiano Ronaldo's son puts him to shame with sit ups

The sportsman began his exercise session with his boy, who helped Cristiano keep his balance by sitting on his feet.

However the little man grew weary of the task and opted to give his father more of a challenge - by adding resistance with his hands and head on his midsection.

Not able to fully complete his set with Cristiano Jr's restricting his movements, he ended at 16 sit-ups and decided to put the boy through the paces.

'I've done mine, so now it's your turn,' he said, adding, 'Just 10.'

Fast moves: He was surpassed in speed by his four-year-old son Cristiano Jr when they performed a workout routine together

Encouraging: The father-of-one coached his boy through the exercise

Like a pro! Cristiano Jr displayed impressive physicality

Swapping roles, Cristiano sits on his son's feet as the youngster displays impressive physicality and quickly gets through the exercise. 

'The last one,' the proud father said, encouragingly when he neared the final sit-up. 

After the set was complete he added: 'And you're the champion!' and wrapped his arms around the boy before planting a kiss. 

Doting dad: He showered his little boy with praise after he completed the challenge

Affectionate: The sportsman celebrated his mini-me's impressive work

Future champ: Cristiano has said that he would like his mini-me to follow in his footsteps 

The CR7 underwear model has previously said that he would be happy to develop his son into an athlete, but he would still be proud if he did not follow in his footsteps.

'I would love him to like football, for him to be my successor, but we'll see what happens, he said. 'My son will be whatever he wants.'

Cristiano became a father for the first time in July 2010, and he has said that being a parent has changed him for the better.

'Of course something like this affects you. It's a different type of responsibility,' he said