Abstract
Well matched unacclimatised older (age 55-68, 4 women, 2 men) and younger (age 19-30, 4 women, 2 men) subjects performed 75 min cycle exercise (∼40% {Mathematical expression}) in a hot environment (37°C, 60% rh). Rectal temperature (Tre), mean skin temperature (-Tsk), arm blood flow (ABF, strain gauge plethysmography), and cardiac output (Q, CO2 rebreathing) were measured to examine age-related differences in heat-induced vasodilatation. Tre and -Tsk rose to the same extent in each group during the exposure. There was no significant intergroup difference in sweat rate (older: 332±43 ml · m-2 · h-1, younger: 435±49 ml · m-2 · h-1; mean±SEM). However, the older subjects responded to exercise in the heat with a lower ABF response which could be attributed to a lower {Mathematical expression} for the same exercise intensity. The slope of the ABF-Tre relationship was attenuated in the older subjects (9.3±1.3 vs 17.9±3.3 ml · 100 ml-1 · min-1 · °C-1, p <0.05), but the Tre threshold for vasodilatation was about 37.0°C for both groups. These results suggest an altered control of skin vasodilatation during exercise in the heat in older individuals. This attenuated ABF response appears to be unrelated to {Mathematical expression}, and may reflect an age-related change in thermoregulatory cardiovascular function.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 120-125 |
| Number of pages | 6 |
| Journal | European Journal of Applied Physiology and Occupational Physiology |
| Volume | 57 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 1 1988 |
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All Science Journal Classification (ASJC) codes
- Physiology
- Public Health, Environmental and Occupational Health
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Control of heat-induced cutaneous vasodilatation in relation to age. / Kenney, W. Larry.
In: European Journal of Applied Physiology and Occupational Physiology, Vol. 57, No. 1, 01.01.1988, p. 120-125.Research output: Contribution to journal › Article
TY - JOUR
T1 - Control of heat-induced cutaneous vasodilatation in relation to age
AU - Kenney, W. Larry
PY - 1988/1/1
Y1 - 1988/1/1
N2 - Well matched unacclimatised older (age 55-68, 4 women, 2 men) and younger (age 19-30, 4 women, 2 men) subjects performed 75 min cycle exercise (∼40% {Mathematical expression}) in a hot environment (37°C, 60% rh). Rectal temperature (Tre), mean skin temperature (-Tsk), arm blood flow (ABF, strain gauge plethysmography), and cardiac output (Q, CO2 rebreathing) were measured to examine age-related differences in heat-induced vasodilatation. Tre and -Tsk rose to the same extent in each group during the exposure. There was no significant intergroup difference in sweat rate (older: 332±43 ml · m-2 · h-1, younger: 435±49 ml · m-2 · h-1; mean±SEM). However, the older subjects responded to exercise in the heat with a lower ABF response which could be attributed to a lower {Mathematical expression} for the same exercise intensity. The slope of the ABF-Tre relationship was attenuated in the older subjects (9.3±1.3 vs 17.9±3.3 ml · 100 ml-1 · min-1 · °C-1, p <0.05), but the Tre threshold for vasodilatation was about 37.0°C for both groups. These results suggest an altered control of skin vasodilatation during exercise in the heat in older individuals. This attenuated ABF response appears to be unrelated to {Mathematical expression}, and may reflect an age-related change in thermoregulatory cardiovascular function.
AB - Well matched unacclimatised older (age 55-68, 4 women, 2 men) and younger (age 19-30, 4 women, 2 men) subjects performed 75 min cycle exercise (∼40% {Mathematical expression}) in a hot environment (37°C, 60% rh). Rectal temperature (Tre), mean skin temperature (-Tsk), arm blood flow (ABF, strain gauge plethysmography), and cardiac output (Q, CO2 rebreathing) were measured to examine age-related differences in heat-induced vasodilatation. Tre and -Tsk rose to the same extent in each group during the exposure. There was no significant intergroup difference in sweat rate (older: 332±43 ml · m-2 · h-1, younger: 435±49 ml · m-2 · h-1; mean±SEM). However, the older subjects responded to exercise in the heat with a lower ABF response which could be attributed to a lower {Mathematical expression} for the same exercise intensity. The slope of the ABF-Tre relationship was attenuated in the older subjects (9.3±1.3 vs 17.9±3.3 ml · 100 ml-1 · min-1 · °C-1, p <0.05), but the Tre threshold for vasodilatation was about 37.0°C for both groups. These results suggest an altered control of skin vasodilatation during exercise in the heat in older individuals. This attenuated ABF response appears to be unrelated to {Mathematical expression}, and may reflect an age-related change in thermoregulatory cardiovascular function.
UR - http://www.scopus.com/inward/record.url?scp=0023927724&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0023927724&partnerID=8YFLogxK
U2 - 10.1007/BF00691250
DO - 10.1007/BF00691250
M3 - Article
C2 - 3342787
AN - SCOPUS:0023927724
VL - 57
SP - 120
EP - 125
JO - European Journal of Applied Physiology
JF - European Journal of Applied Physiology
SN - 1439-6319
IS - 1
ER -