Since 1980, more than 100 events have been added to the Summer Olympics. This year's Games, which is set to officially start in Tokyo with the opening ceremony on July 23, will feature 339 events across 33 sports. Five new sports—sport climbing, karate, surfing, 3x3 basketball and skateboarding—are set to debut.
But before we take in this year's events, let's take a look back at past Games and see which Olympians have racked up the most medals of all time.
U.S. swimmer Michael Phelps leads all Olympians with 28 medals—23 gold, three silver and two bronze.