Red blood cell the body right away and only the plasma is collected. Some athletes have tried to improve their performance by blood doping: first about 1 litre of their blood is extracted, then the red blood cells are isolated, frozen and stored, to be reinjected shortly before the competition. (Red blood cells can be conserved for 5 weeks at , or over 10 years using cryoprotectants) This practice is hard to detect but may endanger the human cardiovascular system which is not equipped to deal with blood of the resulting higher viscosity. Another method of blood doping involves injection with erythropoietin in
U2 Live at Red Rocks: Under a Blood Red Sky U2 Live at Red Rocks: Under a Blood Red Sky U2 Live at Red Rocks: Under a Blood Red Sky is a concert film by Irish rock band U2. It was recorded on 5 June 1983 at Red Rocks Amphitheatre in Colorado, United States, on the group's War Tour. Originally released in 1984 on videocassette, "U2 Live at Red Rocks" was the band's first video release. It accompanied a 1983 live album entitled "Under a Blood Red Sky", on which two tracks from the film appear. The video was directed by Gavin Taylor and produced by Rick Wurpel and Doug