Exercise & Muscle Directory. Running in the Heat. "Runnning in the Heat; Respect Your Body, Respect the Heat" by Mindy Solkin Of all the adversities that runners and marathoners face, heat is the number one offender.
This is because it can bring on two conditions that can negatively affect your performance… Overheating and Dehydration. Overheating is the result of inadequate cooling; when the body cannot keep up with the demands of evaporation of water from your skin. When the body heats up internally, it starts to sweat and sends more blood to the skin where it is cooled by coming into contact with the relatively cooler skin. However, while running, your body's demand for oxygen to the muscles means less blood will flow to the skin and this is when overheating occurs. The Once and Future Way to Run.