Cargando…

Heat, Hydration and the Human Brain, Heart and Skeletal Muscles

People undertaking prolonged vigorous exercise experience substantial bodily fluid losses due to thermoregulatory sweating. If these fluid losses are not replaced, endurance capacity may be impaired in association with a myriad of alterations in physiological function, including hyperthermia, hyperv...

Descripción completa

Detalles Bibliográficos
Autores principales: Trangmar, Steven J., González-Alonso, José
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Springer International Publishing 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6445826/
https://www.ncbi.nlm.nih.gov/pubmed/30671905
http://dx.doi.org/10.1007/s40279-018-1033-y
_version_ 1783408247276830720
author Trangmar, Steven J.
González-Alonso, José
author_facet Trangmar, Steven J.
González-Alonso, José
author_sort Trangmar, Steven J.
collection PubMed
description People undertaking prolonged vigorous exercise experience substantial bodily fluid losses due to thermoregulatory sweating. If these fluid losses are not replaced, endurance capacity may be impaired in association with a myriad of alterations in physiological function, including hyperthermia, hyperventilation, cardiovascular strain with reductions in brain, skeletal muscle and skin blood perfusion, greater reliance on muscle glycogen and cellular metabolism, alterations in neural activity and, in some conditions, compromised muscle metabolism and aerobic capacity. The physiological strain accompanying progressive exercise-induced dehydration to a level of ~ 4% of body mass loss can be attenuated or even prevented by: (1) ingesting fluids during exercise, (2) exercising in cold environments, and/or (3) working at intensities that require a small fraction of the overall body functional capacity. The impact of dehydration upon physiological function therefore depends on the functional demand evoked by exercise and environmental stress, as cardiac output, limb blood perfusion and muscle metabolism are stable or increase during small muscle mass exercise or resting conditions, but are impaired during whole-body moderate to intense exercise. Progressive dehydration is also associated with an accelerated drop in perfusion and oxygen supply to the human brain during submaximal and maximal endurance exercise. Yet their consequences on aerobic metabolism are greater in the exercising muscles because of the much smaller functional oxygen extraction reserve. This review describes how dehydration differentially impacts physiological function during exercise requiring low compared to high functional demand, with an emphasis on the responses of the human brain, heart and skeletal muscles.
format Online
Article
Text
id pubmed-6445826
institution National Center for Biotechnology Information
language English
publishDate 2019
publisher Springer International Publishing
record_format MEDLINE/PubMed
spelling pubmed-64458262019-04-17 Heat, Hydration and the Human Brain, Heart and Skeletal Muscles Trangmar, Steven J. González-Alonso, José Sports Med Review Article People undertaking prolonged vigorous exercise experience substantial bodily fluid losses due to thermoregulatory sweating. If these fluid losses are not replaced, endurance capacity may be impaired in association with a myriad of alterations in physiological function, including hyperthermia, hyperventilation, cardiovascular strain with reductions in brain, skeletal muscle and skin blood perfusion, greater reliance on muscle glycogen and cellular metabolism, alterations in neural activity and, in some conditions, compromised muscle metabolism and aerobic capacity. The physiological strain accompanying progressive exercise-induced dehydration to a level of ~ 4% of body mass loss can be attenuated or even prevented by: (1) ingesting fluids during exercise, (2) exercising in cold environments, and/or (3) working at intensities that require a small fraction of the overall body functional capacity. The impact of dehydration upon physiological function therefore depends on the functional demand evoked by exercise and environmental stress, as cardiac output, limb blood perfusion and muscle metabolism are stable or increase during small muscle mass exercise or resting conditions, but are impaired during whole-body moderate to intense exercise. Progressive dehydration is also associated with an accelerated drop in perfusion and oxygen supply to the human brain during submaximal and maximal endurance exercise. Yet their consequences on aerobic metabolism are greater in the exercising muscles because of the much smaller functional oxygen extraction reserve. This review describes how dehydration differentially impacts physiological function during exercise requiring low compared to high functional demand, with an emphasis on the responses of the human brain, heart and skeletal muscles. Springer International Publishing 2019-01-22 2019 /pmc/articles/PMC6445826/ /pubmed/30671905 http://dx.doi.org/10.1007/s40279-018-1033-y Text en © The Author(s) 2019 Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
spellingShingle Review Article
Trangmar, Steven J.
González-Alonso, José
Heat, Hydration and the Human Brain, Heart and Skeletal Muscles
title Heat, Hydration and the Human Brain, Heart and Skeletal Muscles
title_full Heat, Hydration and the Human Brain, Heart and Skeletal Muscles
title_fullStr Heat, Hydration and the Human Brain, Heart and Skeletal Muscles
title_full_unstemmed Heat, Hydration and the Human Brain, Heart and Skeletal Muscles
title_short Heat, Hydration and the Human Brain, Heart and Skeletal Muscles
title_sort heat, hydration and the human brain, heart and skeletal muscles
topic Review Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6445826/
https://www.ncbi.nlm.nih.gov/pubmed/30671905
http://dx.doi.org/10.1007/s40279-018-1033-y
work_keys_str_mv AT trangmarstevenj heathydrationandthehumanbrainheartandskeletalmuscles
AT gonzalezalonsojose heathydrationandthehumanbrainheartandskeletalmuscles