Accession Number:

ADA220071

Title:

Thermoregulatory Responses to Intermittent Exercise Are Influenced by Knit Structure of Underwear

Descriptive Note:

Corporate Author:

ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA

Personal Author(s):

Report Date:

1990-01-01

Pagination or Media Count:

11.0

Abstract:

The purpose of this study was to evaluate the role of knit structure in underwear on thermoregulatory responses. Underwear manufactured from 100 polypropylene fibres in five different knit structures 1-by-1 rib, fleece, fishnet, interlock, double-layer rib was evaluated. All five underwear prototypes were tested as part of a prototype clothing system. Measured on a thermal manikin these clothing systems had total thermal resistances of 0.243, 0.268, 0.256, 0.248 and 0.250 m2.K.W-1, respectively including a value for the thermal resistance of the ambient environment of 0.104 M2.K.W-1. Human testing was done on eight male subjects and took place at ambient temperature Ta 5 deg. C, dew point temperature Tdp -3.5 C and air velocity Va 0. 32 m.s-1. The test comprised a repeated bout of 40-min cycle exercise 315 W.m- 2 52 SD 4.9 maximal oxygen uptake followed by 20 min of rest 62 W.m-2. The oxygen uptake, heart rate, oesophageal temperature, skin temperature, Ta, Tdp at the skin and in the ambient air, onset of sweating, evaporation rate, non- evaporated sweat accumulated in the clothing and total evaporative loss of mass were measured. Skin wettedness was calculated. The differences in knit structure of the underwear in the clothing systems resulted in significant differences in mean skin temperature, local and average skin wettedness, non-evaporated and evaporated sweat during the course of the intermittent exercise test. No differences were observed over this period in the core temperature measurements. Keywords Thermoregulatory responses, Cold, Intermittent exercise, Underwear.

Subject Categories:

  • Logistics, Military Facilities and Supplies
  • Protective Equipment

Distribution Statement:

APPROVED FOR PUBLIC RELEASE