I finally figured out as this olympics why the swimming is the only watchable event for me. Swimming has heats in the morning and finals in the evening (reversed this year) so when you watch a session, it's all finals or at least semi-finals. For track, they seem to mix the heats with the finals so in a three hours session, there is like one or two finals and 37 heats of various events. Combined with six minutes of commercials between 20 second races, it's just not watchable. The commercials in every other event in the middle of competition make things pretty unwatchable. Overall terrible job by NBC, who also seem to want to insert ridiculous stupid pieces into the middle of events.