<P> A recumbent bicycle is a bicycle that places the rider in a laid - back reclining position . Most recumbent riders choose this type of design for ergonomic reasons: the rider's weight is distributed comfortably over a larger area, supported by back and buttocks . On a traditional upright bicycle, the body weight rests entirely on a small portion of the sitting bones, the feet, and the hands . </P> <P> Most recumbent models also have an aerodynamic advantage; the reclined, legs - forward position of the rider's body presents a smaller frontal profile . A recumbent holds the world speed record for a bicycle, and they were banned from racing under the Union Cycliste Internationale (UCI) in 1934, and now race under the banner of the World Human Powered Vehicle Association (WHPVA) and International Human Powered Vehicle Association (IHPVA). </P>

What are the bikes called where you lay down