The biathlon is an event where athletes combine cross-country skiing and rifle shooting. There are a variety of events under this category, but the part that makes it a serious athletic challenge is that the physical activity induces heavy breathing requirements, and heavy breathing makes accuracy with a rifle extremely difficult to maintain.
Medal leaders as of this time:
The bobsleigh is a kind of sled in which two or four teammates ride (though in the early years of the sport, this number often varied). They steer along a track, which requires a skillful driver and a highly coordinated team effort to accomplish. The bobsleigh at Olympic level competitions travels at very fast speeds (the fastest recorded was just under 120 mph), which also makes the events extremely dangerous, as the bobsleigh and the team inside it add up to a lot of mass; the sheer momentum is such that bones will shatter rather than break.
Bobsleigh events at the 2010 Olympics: