When a teenager called Cristiano Ronaldo left Sporting Lisbon to join Manchester United, few expected him to become one of the greatest players of all time.

Whilst the Portuguese’s talent had never been doubted, some questioned his ability to succeed against the physically-strong Premier League defenders.

In a BBC special documentary, the Red Devils’ former power development coach Mick Clegg tells the routine adopted by CR7, and how he transformed himself into a real physical beast.