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 [ 1], including cardiac rehab patients, to allow slow rebuilding of strength.

In resistance band training, you replace bulky exercise equipment with rubber resistance bands that you stretch. The force it takes to stretch the bands works your muscles just like using free weights or machines.

The colors on a resistance band indicate their weight. Different colors are used in a coding system to differentiate bands of different strengths. For example, a black band could mean it gives 50lbs of resistance whilst a blue band only gives 20lbs.

Resistance bands are assigned a weight range by their variable tension. As the band stretches, it produces more resistance. Therefore manufacturers need to quote a tension range to accurately describe the amount of weight offered by each band. If you think about it, a resistance band is literally a giant elastic band.