After exercise a similar procedure to warming up must be followed in order to prevent discomfort. This is a cool down and it involves light exercise that keeps the heart rate elevated. The purpose is to keep the metabolic rate high and capillaries to enable oxygen to flush through the muscle tissue. Doing so helps remove lactic acid waste created by the exercise. This should stop the blood from staying on the veins, which can cause dizziness if the exercise is stopped quickly. A cool down can also reduce the effect of delayed onset muscle soreness, which often follows strenuous exercise that the body is not used to. The symptoms of this can include tender and painful muscles. This comes about because of the damage that has been done to muscle fibres and connective tissue that surrounds the fibres. The soreness only lasts a few days by which time the muscle fibres have repaired themselves. Delayed onset of muscle soreness becomes more likely if the exercise involves eccentric contractions, which can come about with weight training, polymerics or walking down steep hills. The final part of the cool down should include a period of stretching that is designed to facilitate and improve flexibility, as the muscles will be very warm at this stage.

Note: Some people use the term warming down instead of cooling down.

See also

• Warming up