Men's competitive swimming kicks off at the 2012 Olympics on Saturday, July 28th, with three events qualifying earlier in the day before the finals decide two of the three gold medals later (100-meter breaststroke will take place on Sunday, July 29).
Below, we give a quick breakdown of the three events and what you should expect to see Saturday:
Men's 400-meter individual medley qualifying
This event, scheduled for 3:00 a.m. ET on Saturday, is arguably one of the hardest in competitive swimming, with the 400 meters consisting of 100-meter stretches of all four strokes. Later in the day, the first medals of men's swimming will be handed out during the finals.
Four years ago, this was one of the eight gold medals for Michael Phelps at Beijing, and he's qualified for it again in London. However, fellow American Ryan Lochte comes into the event as the favorite, having beaten Phelps during the Olympic trails.
Men's 400-meter freestyle heats
No Phelps or Lochte in 400-meter freestyle, but still a competitive event nonetheless.
Reigning gold medal medal winner Park Tae-Hwan (South Korea) won this race comfortably in Beijing, and he's back for another run at gold in London. He's considered a big favorite to repeat with gold.
Other notables that could compete for medals include Germany's Paul Biedermann and China's Sun Yang. Americans Conor Dwyer and Peter Vanderkaay will also compete, although neither is expected to medal.
Men's 100-meter breaststroke
There will be a sad ring to this event in London, as Alexander Dale Oen—the 2011 world champion in the 100-meter breaststroke—collapsed and died in late April while training in Phoenix, Arizona. He was just 26 years old.
With the passing of Oen, who would have been considered one of the heavy favorites to win gold in this event in London, the field has opened up slightly.
Japan's Kosuke Kitajima set a world record time in Beijing, where he won his second straight gold medal in the 100-meter breaststroke. He'll be a heavy favorite to win gold for the third straight Olympics.
American Brenden Hansen, who retired from competitive swimming but is now back to challenge Kitajima, could make a case for being the second best swimmer in the pool.