'Life is roller coaster' - Cristiano Ronaldo shared a message on his 37th birthday

Footballing superstar, Cristiano Ronaldo took to social networking site, Instagram to send a message to his fans as he celebrated his 37th birthday on February 5, revealing that life is a "roller coaster".

Ronaldo who is widely considered to be one of the greatest footballers in the history of the sport turned 37 on February 5, with his birthday coming on the heels of Manchester United's shock loss to Middlesbrough in the fourth round of the FA Cup on Friday.

In the photo, Ronaldo is seen alongside partner Georgina Rodriguez and a "CR7" birthday cake. The Portugal international referred to "hard work, high speed, urgent goals, demanding expectations", but appears to have put the FA Cup loss behind him as he shared the things he think "make it all worth it".

"Life is a roller coaster. Hard work, high speed, urgent goals, demanding expectations… But in the end, it all comes down to family, love, honesty, friendship, values that make it all worth it. Thanks for all the messages! 37 and counting!," he wrote in the post.

Despite United's struggles on the pitch, the five-time Ballon d'Or award winner has enjoyed a successful return to Old Trafford, scoring 14 goals in 24 appearances in all competitions so far.