Resistance band
A resistance band is an elastic band used for strength training. They are also commonly used in physical therapy, specifically by convalescents of muscular injuries, including cardiac rehab patients to allow slow rebuilding of strength.
Originating in the early 20th century, the bands were originally made from surgical tubing and the exercises conducted for muscle rehabilitation, and resistance band training is now used widely as part of general fitness and strength training. Their flexibility in use and light weight are a significant advantage for many users.