Gallery: Sports stars who came out of retirement
Michael Phelps this week announced his return to swimming and he is yet another sports star to reverse their retirement decision.
The most decorated Olympian in history follows in the footsteps of other illustrious sporting figures who have returned to their particular sport with varying degrees of success.
Some of the biggest names including Muhammad Ali, Michael Schumacher, Zinedine Zidane and Michael Jordan decided their initial decision was premature and returned to a full media glare.
Here is how some of the biggest names fared out after returning to competitive sport.