NYTimes has published a well researched article about how to prepare for a Marathon that will happen in hot, humid weather conditions. The article says the 54F is the ideal temperature for running a Marathon and each extra degree slows down the runner and takes additional toll on the body. (Now think of the Chennai, Bangalore or Singapore running conditions.. )
Dr. Martin, analyzing performance records for men, calculated that the optimum temperature for a fast marathon was about 54 degrees. Running times, he said, slow by one minute or more with every seven degrees above that, because it becomes more difficult for the body to cool itself.The article continues to talk about a concept called glycerin loading to keep the runners hydrated.
When it is humid, sweat does not easily evaporate, so the body sweats even more. Blood volume drops, and the body has to make a choice: divert blood to the skin for cooling or divert it to the muscles for performance. It sends blood to the skin.
He added that the legal, safe way to do it is through glycerin loading. The technique exploits the unusual properties of glycerin, a thick, gooey sugar alcohol that is sold in drugstores as a lubricant. Each molecule of glycerin absorbs three molecules of water. During a race, the body uses the glycerin for energy. And every time the body metabolizes a molecule of glycerin, Âit unleashes three molecules of water,Â Dr. Martin said.
The result, he said, is that Âyou have a water bank account.ÂGlycerin loading, he added, should be reserved for races of a half marathon or longer, when runners are competing in intense heat for at least an hour and a half