Technical clothing does more than just look and feel good. It actually helps to improve performance and reduce recovery time.
Our body defends itself against overheating in two ways. The first is to sweat, cooling the body through evaporation, and the other is to pump the overheated blood to the surface of the skin, cooling by radiating the heat through the skin
When we wear cotton during exercise the evaporation action of the sweat is severely limited. The cotton absorbs the sweat and traps it within its fibers, not allowing it to evaporate. This has several side effects during exercise:
1. The body perceives that the amount of sweat being emitted is not sufficient to cool the body, so it produces more. This unnecessary increase in sweat increases the rate that a person becomes dehydrated.
2. As a person becomes dehydrated their blood volume decreases. This causes the heart to have to pump harder and faster in order to deliver the blood to the muscles as needed.
3. As more and more sweat gets trapped in the cotton the body is unable to cool itself properly, similar to going outside with wet hair. This puts the body at risk for heat exhaustion/stroke (or in cold weather, hypothermia).
As the body realizes that the sweat is not effectively reducing body temperature, it begins to rely more upon the second form of heat dissipation, radiation. The body begins to redirect blood flow away from the muscles and to the skin. If the blood is in the skin, it is not in the muscles, so the muscles begin to become starved for oxygen and nutrients, causing performance to decrease and adding to recovery time during and after the workout.
The redirection of blood flow again causes the heart to work overtime. The muscles still need basic sustenance, as do the vital organs. The heart has to again increase output by pumping harder and faster to get the blood to all these areas and to cool it at the same time. Remember this is after the heart has already increased output because of the effects of dehydration.
Bottom line: Because cotton does not allow sweat to evaporate, the heart must work overtime to effectively cool the body and still deliver necessary nutrients to other vital areas.
Technical running clothing doesn’t contain cotton so it doesn’t trap moisture. In fact, it helps to dissipate the sweat more effectively so it can evaporate more quickly. This reduces the amount of sweat the body must produce, which decreases the rate of dehydration. It also reduces the amount of blood flow to the surface of the skin, allowing the needed nutrients and oxygen to get to the muscles.
Technical running clothing effectively saves heartbeats, which allows a person to run harder longer and recover more quickly with less effort.