10K's, E.G. is an acronym for 10 kilometer RACES, which are long-distance running events that are usually held on roads or trails. The term is often used to refer to a 10 kilometer race, but can also be used to refer to any type of long-distance running event that is 10 kilometers in length. 10K RACES are popular among recreational and competitive runners alike, and are often used as a way to measure fitness levels and track progress.