Summary
Eight young, sedentary men (aged 34 years, SD 3) and six older moderately active, unacclimated men (aged 57 years, SD 2) walked on a treadmill at 30% of their maximum oxygen consumption up to 3.5 h in a thermoneutral [dry bulb temperature (T db) 21°C, relative humidity (r.h.) 43%)], a warm humid (T db 30°C, r.h. 80%) and a hot dry (T db 40°C, r.h. 20%) environment while wearing ordinary working clothes (0.7 c/o). Their oxgen consumption, heart rate (f c), rectal (T re) and mean skin temperature (Tsk), sweat rate (SR), and evaporative rate (ER) were measured during the tests. The ratings of thermal sensation (TS) and perceived exertion (RPE) were assessed using standard scales. In the heat stress tests, the number of experiments discontinued did not significantly differ between the two groups. The mean levels and end-exercise values of T re, Tsk, f c, TS and RPE were not significantly different between the young and older subjects in any of the environments. In the warm humid environment, however, the T re and RPE of the older subjects increased continuously (P<0.05) during the test compared to the young subjects. No significant difference between the groups was observed in SR or in ER. In the hot dry environment, however, the ER of older men increased more slowly compared to the young men. In spite of some time-related differences observed in T re, RPE, and ER, the older subjects did not exhibit higher f c during exercise in the heat, they were not more hyperthermic and their performance times were similar to the young subjects. Therefore, it was concluded that older calendar age is not necessarily associated with a reduced ability to exercise in a hot environment and other factors, such as physical activity habits and aerobic capacity, may be equally important in determining heat tolerance in the elderly.
Similar content being viewed by others
References
Borg G (1970) Perceived exertion as an indicator of somatic stress. Scand J Rehabil Med 2:92–98
Carton RL, Rhodes EC (1985) A critical review of the literature of ratings scales for perceived exertion. Sports Med 2:198–222
Drinkwater BL, Horvath SM (1979) Heat tolerance and aging. Med Sci Sports Exerc 2:49–55
Drinkwater BL, Bedi JF, Loucks AB, Roche S, Horvath SM (1982) Sweating sensitivity and capacity of women in relation to age. J Appl Physiol 53:671–676
Ellis FP (1972) Mortality from heat illness and heat-aggravated illness in the United States. Environ Res 5:1
Fanger PO (1970) Thermal comfort. Danish Technical Press, Copenhagen
Foster KG, Ellis FP, Dore C, Exton-Smith AN, Weiner JS (1976) Sweat responses in the aged. Age Ageing 5:91–101
Gisolfi CV (1973) Work-heat tolerance derived from interval training. J Appl Physiol 35:349–354
Hellon RF, Lind AR, Weiner JS (1956) The physiological reactions of men of two age groups to a hot environment. J Physiol (Lond) 133:118–131
Henane R, Flandrois R, Charbonnier JD (1977) Increase in sweating sensitivity by endurance conditioning in man. J Appl Physiol 43:822–828
Ilmarinen R (1978) Einflüsse verschiedener Bekleidung auf einige physiologische Größen des Menschen bei Körperarbeit in unterschiedlich erhöhter Umgebungstemperatur und Luftfeuchtigkeit. Thesis, Deutsche Sporthochschule, Cologne
Kenney WL (1988) Control of heat-induced cutaneous vasodilatation in relation to age. Eur J Appl Physiol 57:120–125
Kenney WL, Anderson RK (1988) Responses of older and younger women to exercise in dry and humid heat without fluid replacement. Med Sci Sports Exerc 20:155–160
Lind AR, Leithead CS, McNicol GW (1968) Cardiovascular changes during syncope induced by tilting men in the heat. J Appl Physiol 25:268–276
Lind AR, Humphreys W, Collins KJ, Foster K, Sweetland KF (1970) Influence of age and daily duration of exposure on responses of men to work in heat. J Appl Physiol 38:50–56
Nielsen B (1969) Thermoregulation at rest and exercise. Acta Physiol Scand [Suppl] 323
Pandolf KB, Cadarette BS, Sawka MN, Young AJ, Francesconi RP, Gonzales RR (1988) Thermoregulatory responses of middle-aged and young men during dry-heat acclimation. J Appl Physiol 65:65–71
Saltin B, Hermansen L (1966) Esophageal, rectal and muscle temperature during exercise. J Appl Physiol 21:1757–1762
Shoenfeld Y, Udassin R, Shapiro Y, Ohri A, Sohar E (1978) Age and sex differences in response to short exposure to extreme dry heat. J Appl Physiol 44:1–4
Smolander J, Louhevaara V, Tuomi T, Korhonen O, Jaakkola J (1984) Cardiorespiratory and thermal effects of wearing gas protective clothing. Int Arch Occup Environ Health 54:261–270
Strydom NB (1971) Age as a causal factor in heat stroke. J Afr Inst Mining Metall 72:112–114
Van Rensburg JP, Van Heerden JGA, Celliers CP, Kriel H, Schutte PC, Kielblock AJ (1985) Heat tolerance and age. Chamber of Mines of South Africa, Johannesburg, Research report no. 19/85
Wagner JA, Robinson S, Tzankoff SP, Marino RP (1972) Heat tolerance and acclimatization to work in the heat in relation to age. J Appl Physiol 33:616–622
Yousef MK, Dill DB, Vitez TS, Hillyard SS, Goldman AS (1984) Thermoregulatory responses to desert heat: age, race, and sex. J Gerontol 49:406–414
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Smolander, J., Korhonen, O. & Ilmarinen, R. Responses of young and older men during prolonged exercise in dry and humid heat. Europ. J. Appl. Physiol. 61, 413–418 (1990). https://doi.org/10.1007/BF00236061
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00236061