Cristiano Ronaldo has poked fun at Bruno Fernandes over the Manchester United star's attempt at his abs workout challenge on Instagram.

Due to the coronavirus outbreak, like the rest of us, footballers are being confined to their houses and are doing all they can to stay fit while being unable to train with their teammates.

United great Ronaldo is renowned for his intense fitness regimes which is how he remains one of the world's best players despite being 35-years-old and he issued a 'core crusher' challenge over the weekend to see how many reps fans could do within 45 seconds, with the Portuguese scoring an impressive 142 within the time limit.

Fernandes took up the challenge but was unable to match his compatriot's score, he wrote in an Instagram post: "#NikeLivingRoomCup - Week One. 117 Abs in 45 seconds. Not bad for a Sunday…"

Ronaldo took the opportunity to have a joke with United's new signing and replied on his own Instagram story by writing: "Train your arms instead!"

Cristiano Ronaldo's response to Bruno Fernandes

Ronaldo's challenge was the first of the Nike Living Room Cup, which will see a different professional athlete issue a new task every week for sports stars and fans alike to compete with each other and stay fit indoors during the COVID-19 pandemic.

Fernandes' fellow United teammate and countryman Diogo Dalot also attempted the challenge - which sees participants lie on their back, hold their feet in the air and touch their toes as many times as possible - but only managed 105 reps, falling well short of Ronaldo's total.

The likes of Erling Haaland, Blaise Matuidi and Vinicius Junior attempted the challenge as well but Ronaldo's benchmark was actually beaten by South African runner Caster Semenya, who managed 176 reps.