During, before or after? the best way to perform a cool down is when you reach the end of the session. Warming up the muscles ready for exercise is vital, as for stretching, recent research has found that static stretching can some time promote injuries. It is found that the muscles sometimes can cool down fast whilst static stretching is preformed, when we stop to stretch our heart rate levels start to drop. This will slow down the blood transport around the body leaving less oxygen and generally cooling the muscles.At the University of California researchers found that stretching after exercise was better, as the muscles are warm this will make it easier to lengthen the muscle and reduce soreness in that area. Dynamic stretches are prefect for the warm up and cool down if needed. After exercise stretches are a must as they will help you develop a better range of movement, this will help trigger more muscles into use and great for toning.