A foam roller is a training tool used to perform 'self-manual therapy.' This type of self-massage is achieved by putting your body weight on the foam roller and rolling your muscles or sore points.
Foam rolling can release muscle knots, relieve inflammation and improve your overall health. It can also help increase your flexibility as well as increase blood circulation and lymph flow. Typical ways to use the foam roller are for warmup or as a cool-down exercise to accelerate post-exercise recovery.