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) |
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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 1988 |
All Science Journal Classification (ASJC) codes
- Physiology
- Public Health, Environmental and Occupational Health