Q: Mr. Pedometer you have cautioned us to drink enough water before taking summertime walks. What guidelines can you offer us to help stay hydrated in the heat of summer?
A: We all know that sweating is our body’s way of cooling off our skin, but did you realize that your heart has to beat harder to move warm blood from your internal organs to the skin’s surface so that heat can dissipate? That is another reason to be sure to drink plenty of water on hot days.
Our blood is 92% water. Drink 16 ounces of water an hour before an activity, then three ounces – “two big gulps” – every 20 minutes while outside on hot days, “so that your blood can stay viscous and move easily to the skin’s surface,” says Jian Cui, Ph.D., an associate professor of medicine at Penn State University, in an article from RealSimple magazine.
If hot days make you feel like you are gasping for breath, you really are. Because that blood has to flow to the skin’s surface, your organs to lose oxygen, causing you to breathe faster and harder, according to Lisa Leon, Ph.D., a research physiologist for the U.S. Army. Even those who consider yourselves “morning impaired” should try to do your walking (and other strenuous outdoor activities) as early in the day as possible. “Afternoon air has higher levels of ozone, a gas that is created when heat and UV rays mix with pollutants and oxygen,” and this causes airway irritation – or what American Lung Association advisor Norman Edelman, M.D., calls “sunburn for your lungs.”
So for the next three months, perhaps our sign-off should be amended to