Just like Cristiano Ronaldo is built to score goals, Michael Phelps is built to win golds.

Unquestionably the greatest swimmer ever, it could be argued that he is the greatest athlete of all time, too.

Phelps is 6ft 4in but has a wingspan of 6ft 7in, while his size 14 feet work as flippers in the water. He also has the ability to hyperextend his joints, giving him greater flexibility in the water. 

Phelps reported to have double-jointed ankles, which give those feet-flippers added movement in the water.