Effects of fabric surface energy on human thermophysiological responses during exercise and recovery

The present paper reports a study on influences of fabric surface energy of cotton and polyester garments on clothing microclimates and human thermophysiological responses during intermittent exercise and recovery. Eight healthy males wearing the garments prepared performed exercises and rest according to the following protocol: rest for 30 min, run on treadmill for total 60 min of three sessions with different intensity and duration, and then sit quietly for 30 min for recovery, all at 30 degrees C and relative humidity of 30 %, while the microclimate humidity (H-mc) and temperature (T-mc), the clothing outside surface humidity (H-co) and temperature (T-co), the skin temperatures and ear canal temperature (T-ear_canal) were measured. The garments are made of. (a) hydrophilic and hydrophobic cotton knitted fabrics, and (b) hydrophilic and hydrophobic polyester knitted fabrics. During and after exercise, for cotton, hydrophilic garment resulted in significant lower Delta H-mc, Delta H-co, Delta T-mc during recovery, higher Delta(T) over bar (sk), lower Delta T-ear_canal and Delta T-forehead. For polyester, hydrophilic garment resulted in significantly lower Delta H-co, Delta T-co, higher Delta(T) over bar (sk), higher Delta T-forehead during E1, E2 and recovery session but lower during E3. In summary, surface energy of cotton garments had significant influences on human thermophysiological responses during exercise and recovery, and hydrophilic cotton garment was better than hydrophobic one to reduce heat stress. Surface energy of polyester garments had influences of lower significance, and hydrophilic garment appeared better than hydrophobic garment.