A research report submitted to the Faculty of Medicine, University of the Witwatersrand,
in partial fulfilment of the requirements for the degree
of
Master of Science in Medicine in Applied Physiology.
Johannesburg, 1997. / A post-exercise reduction in blood pressure (BP) may be the primary reason that
athletes suffer from exerclse-assoclated collapse (EAC) at the end ot ultra-endurance
running ever.s. Plasma volume decreases, possibly caused by dehydration, may be
the cause of the decrease til blood pressure, In order to determine whether there is a
correlation between plasma volume changes and the post-exercise BP drop, this study
evaluated alterations in pre- and post-race blood pressures and changes in blood and
plasma volumes, It found that compared to resting values, systolic, dlastollc and mean
arterial blood pressures (mmHg) fell significantly from 119 ± 4, mean ± standard
deviation, 74 ± 8, and 88 ± 5 respectively to '106 ± 14, 62 ± 12 and 77 ± 10 (ps 0,05),
whereas pulse pressure failed to change, Compared to pre-race values, plasma and
blood volume were found not to have changed significantly, During the race plasma
urea (U) and creatinine (C) concentrations increased significantly, whereas body mass
and body mass index both fell significantly. Haernatocrlt, haemoglobin, mean cell
volume, red blood cell number, mean cell haemoglobin concentration, the mean cell
haemoglobin, plasma sodium, potassium, chloride and protein concentrations, the U:C
ratio and osmolality remained constant. There were no significClnt correlations
between changes in plasma or blood volume and changes in blood pressure, These
data support the Idea that a post-race decrease in blood pressure does not result
primarily from an intravascular fluid loss, It is likely therefore that athletes who collapse
at the end of ultraendurance races due to EAC do so as a result of 'post-exercise
hypotension' secondary to venous pooling, and not as a result of a reduction in plasma
volume, / MT2017
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:wits/oai:wiredspace.wits.ac.za:10539/21783 |
| Date | January 1997 |
| Creators | Buntman, Ari Jack |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | Online resource (65 leaves), application/pdf |
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