The Rupp Report: Physiological Apparel – Still Going Strong

Over the summer, the Rupp Report will take a look at functional fabrics and sports apparel, which continue to be very important sectors of the textile industry, from fibers to ready-made apparel. This first report will take a look at the beginnings and the evolution of so-called physiological apparel.
The 2014 soccer World Cup in Brazil is over. In many regions of the world, family life is starting to go back to a more normal way. For more than a month, TV stations around the world broadcasted fascinating sport with strikers that always looked perfectly good thanks to their modern sportswear. How come the outfits look better than the players after 90 or 120 minutes of a tough game?
Physical activities are certainly a way to compensate for the daily stress. Since Olivia Newton-John’s song “Physical” debuted in 1981, a real body consciousness has evolved. The leisure industry followed this trend, and the development of modern sports equipment culminated in new products. In parallel, the textile industry realized a big chance to move away from manufacturing traditional garments toward modern textiles.
Physiological Apparel
As with every product, a precise specification list is a prerequisite for a perfect product. Now, the term “physiological apparel” has been coined. What does this mean? The word “physiology” refers to the study of the function of living organisms. Therefore, apparel physiology is the study of interactions that take place between the body and the apparel. It should provide information about the physiological characteristics of the apparel.
The Right Functions
Physiologically correct apparel includes the proper function of apparel during the performance of physical activity. It is influenced by the correct interaction of the following:

  • fiber material;
  • spinning, weaving or knitting technology;
  • density, thickness and weight of the fabric;
  • dyeing;
  • finishing;
  • cut; and
  • apparel technology.

In general, physiological apparel is based on the interaction of three components in the so-called triangle of Body – Climate – Apparel. The body, the surrounding climate and the apparel make up a system of mutual interdependence. The body and the environment are given. Only the apparel is changed according to the activity of the wearer. An example: Everyone knows that one wears “warm” dresses in winter and “light and airy” dresses in summer. Now, if the person enters a shopping mall in winter, the positive effect turns into a negative situation: with all the warm textiles around the body, the wearer gets hot. That’s already a very simple example of physiological apparel.
Body Temperature — A Key Point
Why does this unpleasant feeling occur? The human body has an operating temperature of some 98.6°F, and the body wants to maintain this temperature. During certain activities, such as sports, the body temperature increases. By secretion of sweat, the body cools back down to its normal temperature. Sweat will generate water vapor, and this vapor can’t be discharged to the outside through the many layers of apparel. The result is a virtual greenhouse effect, and the wearer feels uncomfortable. In this admittedly dramatic example, it is clear to see that the right apparel is the key to wellbeing. It’s not the heat itself that causes difficulties for the human body; it is the unpleasant sensation of heat.
Body Moisture
This sweat secretion process provokes probably the most important requirement of apparel, and of functional sportswear in particular: the removal of body moisture. Body moisture must be able to immediately wick away from the skin to the outside of the apparel. In a dry situation, many fiber materials are capable of removing body moisture. However, the problem starts with the body sweat: natural fibers soak it up, the fabric gets wet, the body starts to feel chilly and the sweat can’t evaporate through the fibers, which are virtually adhered to the body. To avoid this uncomfortable situation, there is only one solution: to use water-repellent or hydrophobic, man-made fibers. That’s why physiological apparel mainly involves using man-made fibers.
The Right Apparel
However, there are different situations — everything changes according to the respective activity. It is always the sweat that influences the human wellbeing. Everyone has apparel in which he feels better, and therefore the feeling is more comfortable than in other products. So to develop physiological apparel is not that easy. Today, after athleticwear, everyday apparel is the most important field of activity for apparel physiologists. If every garment manufacturer would apply this knowledge to its products, there would be no apparel in which one “doesn’t feel well.”
However, every textile professional knows that such an expectation is not realistic. There is a broad spectrum of virtually perfect apparel, and pleasant wearing comfort is a main consideration. Even bedding manufacturers take these considerations very seriously into account, for example, particularly for hospital linens. The reasons for doing so are many: the range of possible combinations of fibers, material and equipment is seemingly endless. Today, the creation of modern apparel and technical textiles is no longer the job of a tailor, but of an engineer. In order to develop optimal apparel for all living and environmental conditions, scientific methods are needed. In the last 25 to 30 years, apparel physiologists have developed these methods successfully and have continuously improved them. But is it really possible to measure comfort? This seems unlikely, but to a certain extent, it is possible today.
Various institutions and the man-made fiber industry have been working for many years on requirements for physiologically correct apparel. The methods have been refined over the past few years, and it is now possible to simulate the behavior and the mechanism of the human body. There are many institutes and organizations around the world that support the textile industry in its endeavor. However, one must be careful to select the right partner, which should be an independent — probably state-owned — institute, or a department of a polytechnic school.
The Swiss Federal Laboratories for Materials Science and Technology (EMPA) is an example for such an independent institute. It is situated as a domain of the Swiss Federal Institutes of Technology, ETH. The aim is to develop materials and systems for the protection and optimal performance of the human body. EMPA claims that its Body Simulation Systems (BSS) develop and run the most advanced physiological measurement systems worldwide; and that, thanks to a human-like apparatus, BSS can simulate human thermoregulation and study the coupled heat and mass transport through multilayer apparel combinations.
In the next report of this series, the Rupp Report will look at the functions and requirements for physiological apparel.
Have Your Say
The sector of functional and smart fabrics is very big. If you, dear reader, have some experience in this field, please let us know your thoughts. Have your say and write to
July 16, 2014