The physiological responses of hypertensive subjects to a single bout of exercise in a hot environment have been investigated. It was the purpose of this study to compare the effect of successive days of exercise in the heat on borderline hypertensive and normotensive individuals, with particular interest being paid to the positive relationship that exists between plasma volume and blood pressure. Eight hypertensive subjects (HT) and 8 normotensive controls (NT) performed a standardized work task, (walking for 60 minutes at 3.5 mph on a 5% grade), in dry heat, (40C, 257. RH), on 7 successive days. Working capacity and acclimatization were compared during two, 90 minute heat tolerance tests (HTT), one prior to, and the other following the acclimation period.Both groups demonstrated a similar degree of heat acclimation, as reflected in significantly lower HTT2 core temperatures, (P< 0.05), and heart rates, (p< 0.01). Plasma volume expansion over the 9 days was also equal for both groups (+77.), but appeared to have no effect on their resting or exercising blood pressures. No differences were observed in the ability of either group to complete the work task, although the HT group exercised at a significantly higher percentage of their maximal oxygen uptake, (p< 0.05), than the NTs.These results indicate that no abbreviation in working capacity is experienced by borderline HT'% during exercise in the heat as a consequence of their high blood pressure. The anticipated elevation in blood pressure as a result of an expansion i n plasma volume did not occur. Consequently, these individuals show the same positive acclimation to exercise in the heat as their NT counterparts. / School of Physical Education
| Identifer | oai:union.ndltd.org:BSU/oai:cardinalscholar.bsu.edu:handle/183801 |
| Date | January 1989 |
| Creators | Davis, Jacqueline A. |
| Contributors | Ball State University. School of Physical Education., Costill, David L. |
| Source Sets | Ball State University |
| Detected Language | English |
| Format | x, 89 leaves : ill. ; 28 cm. |
| Source | Virtual Press |
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