Today I ran for 60 minutes and slowed to a walk for the last two blocks to cool down, allowing my heart rate to lower to something closer to my normal range. I stretched my calves as I walked up the stairs to my porch. Once inside, I stretched for five minutes or more, and it felt great. But I just read that the importance of cooling down is in question. According to an article in the New York Times, the notion of the cool-down remains from the bygone era when lactic acid was believed to cause post-workout muscle soreness. We know now that lactic acid actually fuels the muscles and a little cool-down does nothing to flush the once believed cause of pain out of the muscle. Why the benefits of a cool-down and pain prevention might be mythic, there are times when it is necessary. The NY Times explains:
Exercise researchers say there is only one agreed-on fact about the possible risk of suddenly stopping intense exercise. When you exercise hard, the blood vessels in your legs are expanded to send more blood to your legs and feet. And your heart is pumping fast. If you suddenly stop, your heart slows down, your blood is pooled in your legs and feet, and you can feel dizzy, even pass out.
The cool-down is especially important for elite athletes since they have slower heart rates than the average joe and due to their high fitness level their heart rates return to normal quickly as well, making the pooling of blood even more intense.
I personally enjoy a cool-down period. It punctuates a hard workout and gives me time to transition into my next feat — be it navigating the kids' car pool or making dinner. What about you?