Open water swimming is swimming outside of a regular pool, usually in a lake, or sometimes ocean. In open water swimming, where the events are swum in a body of open water (lake or sea), there are also 5 km, 10 km and 25 km events for men and women. However, only the 10 km event is included in the Olympic schedule, again for both men and women. Open-water competitions are typically separate to other swimming competitions with the exception of the World Championships and the Olympics. Popularity of the sport has grown in recent years, particularly since the 10km open water event was added as an Olympic event in 2005, contested for the first time in the 2008 Olympic Games in Beijing.