Physiological Limits of Exercise in Full-Body Protective Clothing*
János Pórszász, József Tasnádi, Badaoui
Bechara, Miklós Ludván and Gábor Galgóczy
National Institute of Occupational Health, Budapest, Hungary
Corresponding author: János Pórszász, MD, Ph.D.
National Institute of Occupational Health
Budapest, P.O.Box 22.
Phone: (+36) 1 215 7890
FAX: (+36) 1 215 6891
e-mail: 100324.2440@CompuServe.com
* A part of this study has been presented
at the 13th National Congress of the Hungarian Society for Occupational
Health (with international participation), Budapest, 1995.
CEJOEM 1997, 3:242-257
Key words:
Exercise tolerance, full body protective clothing, tympanic temperature
Abbreviations:
ATS = American Thoracic Society;
dTtymp = increase in tympanic temperature above the baseline value
(·C);
EWR = estimated work rate;
HR = heart rate (bpm);
IDLH = immediately dangerous to life and health;
ISS = initial steady state;
LAT = lactic acidosis threshold;
NTS = normal training suit;
SCBA = self contained breathing apparatus;
VCO2 = carbon dioxide output per minute (L/min, STPD);
VE = minute pulmonary ventilation (L/min, BTPS);
VO2 = oxygen consumption per minute (L/min, STPD).
Abstract:
The purpose of the present study was to test the effect of full-body
protective clothing on exercise tolerance and the limiting physiological
changes. Three types of protective clothing (ISOTEMP 4000, ISOTEMP 5500
and SUNIT-GUMOTEX V/a) with different weight and heat insulation characteristics
were tested on seven healthy male subjects. The exercise tolerance was
studied under thermoneutral conditions (room temperature and humidity)
in ramp test, two constant work rates (80% LAT and 10% delta) (ISOTEMP-4000
and ISOTEMP-5500) and in a randomized work rate protocol on treadmill.
Wearing the protective clothing effected in lower achievable external work
rates while the physiological strain was the same. The duration of the
constant work rates as well as the randomized test was limited by an appreciable
extent depending on the actual work rate and type of test applied (18%–54%).
The least limitation was found in case of the small-weight G-V/a type clothing.
In addition to the limitation accountable for the excess weight the subject
has to carry the heat strain caused by the impeded heat dissipation mechanisms
contributes to the increase in physiological strain. It is emphasized that
the level (i.e. in respect to the individual LAT), type (constant/impulsive)
and duration of work needs to be closely regulated while working in full-body
protective clothing under extreme work conditions. Since the core temperature
continues to rise in recovery it is necessary to take the clothing off
as soon as possible after the task has been accomplished and/or the allowable
time limit has reached. This study has shown that the use of full-body
protective clothing can lead to extreme strain, therefore, it is suggested
that the persons selected for the use of full-body protective clothing
and the SCBA should prove their excellent exercise tolerance. In addition,
a regular exercise training program should help to maintain the excellence
in fitness.
Received: 28 July 1997
Accepted: 25 August 1997
Posted: 25 November 1998 |
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