What is a cool-down, and how important is it in aerobic activity?
After any aerobic activity, the blood is pooled in the extremities, and the heartrate is elevated. The purpose of the cool-down is to bring the heartrate down to near-normal and to get the blood circulating freely back to the heart. Stopping abruptly could result in fainting or place undue stress on the heart. The cool-down should also include stretching to help relax the muscles which worked so hard during the activity. The cool-down stretches also increase flexibility, and might help to prevent DOMS (Delayed Onset Muscle Soreness) although this has not been proven.
