Updated

Tuesday at the 2012 Summer Olympics is another full day of must-see events in London, starting very early with the men's triathlon at 6:30 a.m. ET. But trust me -- it's worth getting up for! Triathlon features some of the world's fittest athletes competing in what amounts to a sprint, in the water, on bike and finally in a run for the finish line. It should be especially electric Tuesday morning in London, with two of the medal favorites, the Brownlee brothers, being British.

Elsewhere at the Summer Games, medals will be decided in gymnastics -- women's beam, men's horizontal bar and and women's floor -- and on the track, with the finals in women's 100m hurdles and men's high jump.

What To Watch at the 2012 Summer Olympics, Aug. 7:

Men's Triathlon, 6:30 a.m. ET, NBC Sports Network

As the women's triathlon showed, this can come down to a dramatic photo finish, even if it consists of a 1500-meter swim, a 43km bike and a 10km run. (By the way, they complete all that -- with two transitions -- in about an hour and 50 minutes.) There are two Americans in the field -- Hunter Kemper and Manuel Huerta -- but this race is already all but decided. Great Britain's Alistair Brownlee is the overwhelming favorite. And if he somehow doesn't win, then his brother, Jonathan, probably will.

Gymnastics - Women's Beam, 8 p.m., NBC (LIVE at 9:47 a.m.)

Americans Gabby Douglas and Aly Raisman will perform ridiculous flips and spins on a piece of wood only 3.9 inches wide. But both will likely be chasing China's Sui Lu, the 2011 World Champion.

Gymnastics - Men's Horizontal Bar, 8 p.m. ET, NBC (LIVE at 10:37 a.m.)

Danell Leyva and Jonathan Horton, the defending Olympic silver medalist, are in competition, but the heavy favorite is China's Zou Kai, the 2011 World Champion and 2008 gold medal winner. Let's just hope no one gets stuck again =/

Gymnastics, Women's Floor Exercise, 8 p.m. ET, NBC (LIVE at 11:23 a.m.)

Team USA Jordyn Wieber and Aly Raisman are in the finals and will look to bring home two medals to America, much like Nastia Liukin and Shawn Johnson did in 2008. Unfortunately for them, Sandra Izbasa, defending gold medalist, is also in the competition.

Track Cycling: Men's Kerlin, Second Round (11:30 a.m.), Women's Ominum, Sprint (12 p.m.), Men's Kerlin Gold Medal Final (1 p.m.), NBC

More insanity on the track!

Men's High Jump (LIVE at 2 p.m.)

Russia's Andrey Silnov will look to defend his gold medal from 2008 -- can you imagine jumping over a bar 7.7 feet in the air?? -- but should face a challenge from American Jesse Williams, 2011 World Champion.

Women's 100m hurdles, 8 p.m. ET, NBC (LIVE at 4 p.m.)

The semifinals are set for 2:15 p.m. ET, with three members of Team USA in the three heats: Dawn Harper, the defending gold medalist, Lolo Jones, looking for redemption after Beijing, and Kellie Wells.

Men's 1500m, 8 p.m. ET, NBC (LIVE at 4:15 p.m.)

Kenya has won this six medals in men's 1500m (0.932 miles) since 1998, including three gold (most recently, Asbel Kiprop's win in Beijing). And London may be no different, with two of the fastest semifinal times coming from Kenyans, but keep an eye on American Matthew Centrowitz, the bronze medalist at the 2011 World Championships -- he had the fifth-fastest time. No American has medaled in this event since jim Ryun's silver, in 1968.

Women's beach volleyball semis, 8 p.m. ET, NBC (LIVE at 1 p.m. and 4 p.m.)

Team USA will look to make it an all-American gold medal match when Misty May-Treanor and Kerri Walsh face off against China's Chen Xue and Xi Zhang -- the No. 1 team in the world -- at 1 p.m. ET, followed by the U.S. team of April Ross and Jennifer Kessy meeting Brazil's Larissa Franca and Juliana Silva, the world's No. 2 team.

For more on the Olympics, check out SB Nation's London 2012 Olympics Hub.