Health & Fitness: Intravenous Aerobics

Athletes will try almost anything, it seems, to better their performances. The % boost of choice among some is blood doping, in which red blood cells are drawn off and reinjected a few days before a race. Since red cells carry muscle- fueling oxygen, an additional infusion should translate into greater energy, more endurance and improved times.

The 1984 U.S. Olympic cycling coach was suspended after some team members admitted to doping their blood, a practice now banned from the Games. Blood doping is arguably unethical; it may also have long-term side effects and has been clinically unproven. Last month, though,...