Hypohydration causes cardiovascular drift without reducing blood volume
Deutscher übersetzter Titel: | Hypohydratation verursacht einen Herz-Kreislauf-Antrieb ohne Verminderung des Blutvolumens |
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Autor: | Heaps, C.L.; Gonzales-Alonso, J.; Coyle, E.F. |
Erschienen in: | International journal of sports medicine |
Veröffentlicht: | 15 (1994), 2, S. 74-79, Lit. |
Format: | Literatur (SPOLIT) |
Publikationstyp: | Zeitschriftenartikel |
Medienart: | Gedruckte Ressource Elektronische Ressource (online) |
Sprache: | Englisch |
ISSN: | 0172-4622, 1439-3964 |
DOI: | 10.1055/s-2007-1021023 |
Schlagworte: | |
Online Zugang: | |
Erfassungsnummer: | PU199408071457 |
Quelle: | BISp |
Abstract des Autors
To determine the effect of hydration on cardiovascular drift (i.e.; increased heart rate and reduced stroke volume) during exercise in a 21 deg C environment, nine subjects were studied while cycling at 65% of peak oxygen consumption when euhydrated and while still hypohydrate, following exerise-induced dehydration and a 2 h rest/rehydration period. Subjects dehydrated by exercising in the heat (32 deg C) until body weight was reduced 2.5%. On two separate occasions following exercise, subjects either received no fluid or ingested a volume of water equal to 100% of the fluid lost during exercise. Following the 2 h rest/rehydration period, 65 +/- 6% of the ingested water was retained and thus the subjects were hypohydrated by 0.9 +/- 0.1%, compared to being hypohydrated by 2.8 +/- 0.1% when no fluid was ingested. Despite these differences in whole body hydration, blood volume during exercise remained at euhydrated levels when hypohydrated by 0.9% and 2.8%. However, the degree of cardiovascular drift was graded in proportion to hypohydration. Compared to the responses when euhydrated, heart rate was elevated 10 +/- 2 and 18 +/- 2 bt/min, whereas stroke volume was reduced 9 +/- 3 and 18 +/- 2 ml/bt, respectively, when hypohydrated by 0.9% and 2.8% during the water and no fluid trials. These observations indicate that cardiovascular drift during exercise in a 21 deg C environment is graded in proportion to hydration and, under these conditions, not due to reductions in blood volume. Verf.-Referat