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Rodríguez de Rivera M, Rodríguez de Rivera PJ. New, Optimized Skin Calorimeter Version for Measuring Thermal Responses of Localized Skin Areas during Physical Activity. SENSORS (BASEL, SWITZERLAND) 2024; 24:5927. [PMID: 39338672 PMCID: PMC11435610 DOI: 10.3390/s24185927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2024] [Revised: 09/04/2024] [Accepted: 09/11/2024] [Indexed: 09/30/2024]
Abstract
We present an optimized version of the skin calorimeter for measuring localized skin thermal responses during physical activity. Enhancements include a new holding system, more sensitive thermopiles, and an upgraded spiked heat sink for improved efficiency. In addition, we used a new, improved calorimetric model that takes into account all the variables that influence the measurement process. Resolution in power measurement is 1 mW. Performance tests under air currents and movement disturbances showed that the device maintains high accuracy; the deviation produced by these significant disturbances is less than 5%. Human subject tests, both at rest and during exercise, confirmed its ability to accurately measure localized skin heat flux, heat capacity, and thermal resistance (less than 5% uncertainty). These findings highlight the calorimeter's potential for applications in sports medicine and physiological studies.
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Rissanen APE, Mikkola T, Gagnon DD, Lehtonen E, Lukkarinen S, Peltonen JE. Wagner diagram for modeling O 2pathway-calculation and graphical display by the Helsinki O 2Pathway Tool. Physiol Meas 2024; 45:055028. [PMID: 38749432 DOI: 10.1088/1361-6579/ad4c36] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2023] [Accepted: 05/15/2024] [Indexed: 06/06/2024]
Abstract
Objective.Maximal O2uptake (V˙O2max) reflects the individual's maximal rate of O2transport and utilization through the integrated whole-body pathway composed of the lungs, heart, blood, circulation, and metabolically active tissues. As such,V˙O2maxis strongly associated with physical capacity as well as overall health and thus acts as one predictor of physical performance and as a vital sign in determination of status and progress of numerous clinical conditions. Quantifying the contribution of single parts of the multistep O2pathway toV˙O2maxprovides mechanistic insights into exercise (in)tolerance and into therapy-, training-, or disuse-induced adaptations at individual or group levels. We developed a desktop application (Helsinki O2Pathway Tool-HO2PT) to model numerical and graphical display of the O2pathway based on the 'Wagner diagram' originally formulated by Peter D. Wagner and his colleagues.Approach.The HO2PT was developed and programmed in Python to integrate the Fick principle and Fick's law of diffusion into a computational system to import, calculate, graphically display, and export variables of the Wagner diagram.Main results.The HO2PT models O2pathway both numerically and graphically according to the Wagner diagram and pertains to conditions under which the mitochondrial oxidative capacity of metabolically active tissues exceeds the capacity of the O2transport system to deliver O2to the mitochondria. The tool is based on the Python open source code and libraries and freely and publicly available online for Windows, macOS, and Linux operating systems.Significance.The HO2PT offers a novel functional and demonstrative platform for those interested in examiningV˙O2maxand its determinants by using the Wagner diagram. It will improve access to and usability of Wagner's and his colleagues' integrated physiological model and thereby benefit users across the wide spectrum of contexts such as scientific research, education, exercise testing, sports coaching, and clinical medicine.
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Affiliation(s)
- Antti-Pekka E Rissanen
- Helsinki Sports and Exercise Medicine Clinic, Foundation for Sports and Exercise Medicine (HULA), Helsinki, Finland
- Sports and Exercise Medicine, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Tom Mikkola
- Helsinki Sports and Exercise Medicine Clinic, Foundation for Sports and Exercise Medicine (HULA), Helsinki, Finland
- School of Information and Communication Technology, Metropolia University of Applied Sciences, Helsinki, Finland
| | - Dominique D Gagnon
- Helsinki Sports and Exercise Medicine Clinic, Foundation for Sports and Exercise Medicine (HULA), Helsinki, Finland
- Sports and Exercise Medicine, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- Faculty of Sports and Health Sciences, University of Jyväskylä, Jyväskylä, Finland
- School of Kinesiology and Health Sciences, Laurentian University, Sudbury, ON, Canada
| | - Elias Lehtonen
- Helsinki Sports and Exercise Medicine Clinic, Foundation for Sports and Exercise Medicine (HULA), Helsinki, Finland
- Sports and Exercise Medicine, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Sakari Lukkarinen
- School of Information and Communication Technology, Metropolia University of Applied Sciences, Helsinki, Finland
| | - Juha E Peltonen
- Helsinki Sports and Exercise Medicine Clinic, Foundation for Sports and Exercise Medicine (HULA), Helsinki, Finland
- Sports and Exercise Medicine, Faculty of Medicine, University of Helsinki, Helsinki, Finland
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3
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Notley SR, Mitchell D, Taylor NAS. A century of exercise physiology: concepts that ignited the study of human thermoregulation. Part 3: Heat and cold tolerance during exercise. Eur J Appl Physiol 2024; 124:1-145. [PMID: 37796292 DOI: 10.1007/s00421-023-05276-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 07/04/2023] [Indexed: 10/06/2023]
Abstract
In this third installment of our four-part historical series, we evaluate contributions that shaped our understanding of heat and cold stress during occupational and athletic pursuits. Our first topic concerns how we tolerate, and sometimes fail to tolerate, exercise-heat stress. By 1900, physical activity with clothing- and climate-induced evaporative impediments led to an extraordinarily high incidence of heat stroke within the military. Fortunately, deep-body temperatures > 40 °C were not always fatal. Thirty years later, water immersion and patient treatments mimicking sweat evaporation were found to be effective, with the adage of cool first, transport later being adopted. We gradually acquired an understanding of thermoeffector function during heat storage, and learned about challenges to other regulatory mechanisms. In our second topic, we explore cold tolerance and intolerance. By the 1930s, hypothermia was known to reduce cutaneous circulation, particularly at the extremities, conserving body heat. Cold-induced vasodilatation hindered heat conservation, but it was protective. Increased metabolic heat production followed, driven by shivering and non-shivering thermogenesis, even during exercise and work. Physical endurance and shivering could both be compromised by hypoglycaemia. Later, treatments for hypothermia and cold injuries were refined, and the thermal after-drop was explained. In our final topic, we critique the numerous indices developed in attempts to numerically rate hot and cold stresses. The criteria for an effective thermal stress index were established by the 1930s. However, few indices satisfied those requirements, either then or now, and the surviving indices, including the unvalidated Wet-Bulb Globe-Thermometer index, do not fully predict thermal strain.
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Affiliation(s)
- Sean R Notley
- Defence Science and Technology Group, Department of Defence, Melbourne, Australia
- School of Human Kinetics, University of Ottawa, Ottawa, Canada
| | - Duncan Mitchell
- Brain Function Research Group, School of Physiology, University of the Witwatersrand, Johannesburg, South Africa
- School of Human Sciences, University of Western Australia, Crawley, Australia
| | - Nigel A S Taylor
- Research Institute of Human Ecology, College of Human Ecology, Seoul National University, Seoul, Republic of Korea.
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Koch Esteves N, Khir AW, González‐Alonso J. Lower limb hyperthermia augments functional hyperaemia during small muscle mass exercise similarly in trained elderly and young humans. Exp Physiol 2023; 108:1154-1171. [PMID: 37409754 PMCID: PMC10988472 DOI: 10.1113/ep091275] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 06/23/2023] [Indexed: 07/07/2023]
Abstract
NEW FINDINGS What is the central question of the study? Ageing is postulated to lead to underperfusion of human limb tissues during passive and exertional hyperthermia, but findings to date have been equivocal. Thus, does age have an independent adverse effect on local haemodynamics during passive single-leg hyperthermia, single-leg knee-extensor exercise and their combination? What is the main finding and its importance? Local hyperthermia increased leg blood flow over three-fold and had an additive effect during knee-extensor exercise with no absolute differences in leg perfusion between the healthy, exercise-trained elderly and the young groups. Our findings indicate that age per se does not compromise lower limb hyperaemia during local hyperthermia and/or small muscle mass exercise. ABSTRACT Heat and exercise therapies are recommended to improve vascular health across the lifespan. However, the haemodynamic effects of hyperthermia, exercise and their combination are inconsistent in young and elderly people. Here we investigated the acute effects of local-limb hyperthermia and exercise on limb haemodynamics in nine healthy, trained elderly (69 ± 5 years) and 10 young (26 ± 7 years) adults, hypothesising that the combination of local hyperthermia and exercise interact to increase leg perfusion, albeit to a lesser extent in the elderly. Participants underwent 90 min of single whole-leg heating, with the contralateral leg remaining as control, followed by 10 min of low-intensity incremental single-leg knee-extensor exercise with both the heated and control legs. Temperature profiles and leg haemodynamics at the femoral and popliteal arteries were measured. In both groups, heating increased whole-leg skin temperature and blood flow by 9.5 ± 1.2°C and 0.7 ± 0.2 L min-1 (>3-fold), respectively (P < 0.0001). Blood flow in the heated leg remained 0.7 ± 0.6 and 1.0 ± 0.8 L min-1 higher during exercise at 6 and 12 W, respectively (P < 0.0001). However, there were no differences in limb haemodynamics between cohorts, other than the elderly group exhibiting a 16 ± 6% larger arterial diameter and a 51 ± 6% lower blood velocity following heating (P < 0.0001). In conclusion, local hyperthermia-induced limb hyperperfusion and/or small muscle mass exercise hyperaemia are preserved in trained older people despite evident age-related structural and functional alterations in their leg conduit arteries.
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Affiliation(s)
- Nuno Koch Esteves
- Division of Sport, Health, and Exercise Sciences, Department of Life SciencesBrunel University LondonUxbridgeUK
| | | | - José González‐Alonso
- Division of Sport, Health, and Exercise Sciences, Department of Life SciencesBrunel University LondonUxbridgeUK
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Caddye E, Pineau J, Reyniers J, Ronen I, Colasanti A. Lactate: A Theranostic Biomarker for Metabolic Psychiatry? Antioxidants (Basel) 2023; 12:1656. [PMID: 37759960 PMCID: PMC10526106 DOI: 10.3390/antiox12091656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 08/01/2023] [Accepted: 08/16/2023] [Indexed: 09/29/2023] Open
Abstract
Alterations in neurometabolism and mitochondria are implicated in the pathophysiology of psychiatric conditions such as mood disorders and schizophrenia. Thus, developing objective biomarkers related to brain mitochondrial function is crucial for the development of interventions, such as central nervous system penetrating agents that target brain health. Lactate, a major circulatory fuel source that can be produced and utilized by the brain and body, is presented as a theranostic biomarker for neurometabolic dysfunction in psychiatric conditions. This concept is based on three key properties of lactate that make it an intriguing metabolic intermediate with implications for this field: Firstly, the lactate response to various stimuli, including physiological or psychological stress, represents a quantifiable and dynamic marker that reflects metabolic and mitochondrial health. Second, lactate concentration in the brain is tightly regulated according to the sleep-wake cycle, the dysregulation of which is implicated in both metabolic and mood disorders. Third, lactate universally integrates arousal behaviours, pH, cellular metabolism, redox states, oxidative stress, and inflammation, and can signal and encode this information via intra- and extracellular pathways in the brain. In this review, we expand on the above properties of lactate and discuss the methodological developments and rationale for the use of functional magnetic resonance spectroscopy for in vivo monitoring of brain lactate. We conclude that accurate and dynamic assessment of brain lactate responses might contribute to the development of novel and personalized therapies that improve mitochondrial health in psychiatric disorders and other conditions associated with neurometabolic dysfunction.
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Affiliation(s)
- Edward Caddye
- Clinical Imaging Sciences Centre, Brighton and Sussex Medical School, University of Sussex, Falmer BN1 9RR, UK
- Department of Clinical Neuroscience, Brighton and Sussex Medical School, University of Sussex, Falmer BN1 9RR, UK
| | - Julien Pineau
- Independent Researcher, Florianópolis 88062-300, Brazil
| | - Joshua Reyniers
- Department of Clinical Neuroscience, Brighton and Sussex Medical School, University of Sussex, Falmer BN1 9RR, UK
- School of Life Sciences, University of Sussex, Falmer BN1 9RR, UK
| | - Itamar Ronen
- Clinical Imaging Sciences Centre, Brighton and Sussex Medical School, University of Sussex, Falmer BN1 9RR, UK
| | - Alessandro Colasanti
- Clinical Imaging Sciences Centre, Brighton and Sussex Medical School, University of Sussex, Falmer BN1 9RR, UK
- Department of Clinical Neuroscience, Brighton and Sussex Medical School, University of Sussex, Falmer BN1 9RR, UK
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Richard NA, Koehle MS. Influence and Mechanisms of Action of Environmental Stimuli on Work Near and Above the Severe Domain Boundary (Critical Power). SPORTS MEDICINE - OPEN 2022; 8:42. [PMID: 35347469 PMCID: PMC8960528 DOI: 10.1186/s40798-022-00430-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/24/2021] [Accepted: 02/26/2022] [Indexed: 11/10/2022]
Abstract
Abstract
The critical power (CP) concept represents the uppermost rate of steady state aerobic metabolism during work. Work above CP is limited by a fixed capacity (W′) with exercise intensity being an accelerant of its depletion rate. Exercise at CP is a considerable insult to homeostasis and any work done above it will rapidly become intolerable. Humans live and exercise in situations of hypoxia, heat, cold and air pollution all of which impose a new environmental stress in addition to that of exercise. Hypoxia disrupts the oxygen cascade and consequently aerobic energy production, whereas heat impacts the circulatory system’s ability to solely support exercise performance. Cold lowers efficiency and increases the metabolic cost of exercise, whereas air pollution negatively impacts the respiratory system. This review will examine the effects imposed by environmental conditions on CP and W′ and describe the key physiological mechanisms which are affected by the environment.
Graphical Abstract
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Chou TH, Coyle EF. Cardiovascular responses to hot skin at rest and during exercise. Temperature (Austin) 2022; 10:326-357. [PMID: 37554384 PMCID: PMC10405766 DOI: 10.1080/23328940.2022.2109931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 07/25/2022] [Accepted: 07/30/2022] [Indexed: 10/15/2022] Open
Abstract
Integrative cardiovascular responses to heat stress during endurance exercise depend on various variables, such as thermal stress and exercise intensity. This review addresses how increases in skin temperature alter and challenge the integrative cardiovascular system during upright submaximal endurance exercise, especially when skin is hot (i.e. >38°C). Current evidence suggests that exercise intensity plays a significant role in cardiovascular responses to hot skin during exercise. At rest and during mild intensity exercise, hot skin increases skin blood flow and abolishes cutaneous venous tone, which causes blood pooling in the skin while having little impact on stroke volume and thus cardiac output is increased with an increase in heart rate. When the heart rate is at relatively low levels, small increases in heart rate, skin blood flow, and cutaneous venous volume do not compromise stroke volume, so cardiac output can increase to fulfill the demands for maintaining blood pressure, heat dissipation, and the exercising muscle. On the contrary, during more intense exercise, hot skin does not abolish exercise-induced cutaneous venoconstriction possibly due to high sympathetic nerve activities; thus, it does not cause blood pooling in the skin. However, hot skin reduces stroke volume, which is associated with a decrease in ventricular filling time caused by an increase in heart rate. When the heart rate is high during moderate or intense exercise, even a slight reduction in ventricular filling time lowers stroke volume. Cardiac output is therefore not elevated when skin is hot during moderate intensity exercise.
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Affiliation(s)
- Ting-Heng Chou
- Center for Regenerative Medicine, The Research Institute at Nationwide Children’s Hospital, Columbus, OH, USA
| | - Edward F. Coyle
- Department of Kinesiology and Health Education, The University of Texas at Austin, Texas, Tx, USA
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8
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Travers G, Kippelen P, Trangmar SJ, González-Alonso J. Physiological Function during Exercise and Environmental Stress in Humans-An Integrative View of Body Systems and Homeostasis. Cells 2022; 11:383. [PMID: 35159193 PMCID: PMC8833916 DOI: 10.3390/cells11030383] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 01/18/2022] [Accepted: 01/19/2022] [Indexed: 11/26/2022] Open
Abstract
Claude Bernard's milieu intérieur (internal environment) and the associated concept of homeostasis are fundamental to the understanding of the physiological responses to exercise and environmental stress. Maintenance of cellular homeostasis is thought to happen during exercise through the precise matching of cellular energetic demand and supply, and the production and clearance of metabolic by-products. The mind-boggling number of molecular and cellular pathways and the host of tissues and organ systems involved in the processes sustaining locomotion, however, necessitate an integrative examination of the body's physiological systems. This integrative approach can be used to identify whether function and cellular homeostasis are maintained or compromised during exercise. In this review, we discuss the responses of the human brain, the lungs, the heart, and the skeletal muscles to the varying physiological demands of exercise and environmental stress. Multiple alterations in physiological function and differential homeostatic adjustments occur when people undertake strenuous exercise with and without thermal stress. These adjustments can include: hyperthermia; hyperventilation; cardiovascular strain with restrictions in brain, muscle, skin and visceral organs blood flow; greater reliance on muscle glycogen and cellular metabolism; alterations in neural activity; and, in some conditions, compromised muscle metabolism and aerobic capacity. Oxygen supply to the human brain is also blunted during intense exercise, but global cerebral metabolism and central neural drive are preserved or enhanced. In contrast to the strain seen during severe exercise and environmental stress, a steady state is maintained when humans exercise at intensities and in environmental conditions that require a small fraction of the functional capacity. The impact of exercise and environmental stress upon whole-body functions and homeostasis therefore depends on the functional needs and differs across organ systems.
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Affiliation(s)
- Gavin Travers
- The European Astronaut Centre, The European Space Agency, Linder Höhe, 51147 Cologne, Germany;
| | - Pascale Kippelen
- Centre for Human Performance, Exercise and Rehabilitation, Brunel University London, Uxbridge UB8 3PH, UK;
- Division of Sport, Health and Exercise Sciences, Department of Life Sciences, Brunel University London, Uxbridge UB8 3PH, UK
| | - Steven J. Trangmar
- School of Life and Health Sciences, University of Roehampton, London SW15 4JD, UK;
| | - José González-Alonso
- Centre for Human Performance, Exercise and Rehabilitation, Brunel University London, Uxbridge UB8 3PH, UK;
- Division of Sport, Health and Exercise Sciences, Department of Life Sciences, Brunel University London, Uxbridge UB8 3PH, UK
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9
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Wang J, Guan H, Hostrup M, Rowlands DS, González-Alonso J, Jensen J. The Road to the Beijing Winter Olympics and Beyond: Opinions and Perspectives on Physiology and Innovation in Winter Sport. JOURNAL OF SCIENCE IN SPORT AND EXERCISE 2021; 3:321-331. [PMID: 36304069 PMCID: PMC8475427 DOI: 10.1007/s42978-021-00133-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 07/24/2021] [Indexed: 11/28/2022]
Abstract
Beijing will host the 2022 Winter Olympics, and China strengthens research on various aspects to allow their athletes to compete successfully in winter sport. Simultaneously, Government-directed initiatives aim to increase public participation in recreational winter sport. These parallel developments allow research to advance knowledge and understanding of the physiological determinants of performance and health related to winter sport. Winter sport athletes often conduct a substantial amount of training with high volumes of low-to-moderate exercise intensity and lower volumes of high-intensity work. Moreover, much of the training occur at low ambient temperatures and winter sport athletes have high risk of developing asthma or asthma-related conditions, such as exercise-induced bronchoconstriction. The high training volumes require optimal nutrition with increased energy and dietary protein requirement to stimulate muscle protein synthesis response in the post-exercise period. Whether higher protein intake is required in the cold should be investigated. Cross-country skiing is performed mostly in Northern hemisphere with a strong cultural heritage and sporting tradition. It is expected that innovative initiatives on recruitment and training during the next few years will target to enhance performance of Chinese athletes in classical endurance-based winter sport. The innovation potential coupled with resourcing and population may be substantial with the potential for China to become a significant winter sport nation. This paper discusses the physiological aspects of endurance training and performance in winter sport highlighting areas where innovation may advance in athletic performance in cold environments. In addition, to ensure sustainable development of snow sport, a quality ski patrol and rescue system is recommended for the safety of increasing mass participation.
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Affiliation(s)
- Jun Wang
- Department of Exercise Physiology, Beijing Sport University, Beijing, China
| | - Hongwei Guan
- Department of Health Promotion and Physical Education, School of Health Sciences and Human Performance, Ithaca College, Ithaca, NY 14850 USA
| | - Morten Hostrup
- Section of Integrative Physiology, Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark
| | - David S. Rowlands
- School of Sport, Exercise, and Nutrition, College of Health, Massey University, Auckland, New Zealand
| | - José González-Alonso
- Centre for Human Performance, Exercise and Rehabilitation, Brunel University London, Uxbridge, UK
| | - Jørgen Jensen
- Department of Exercise Physiology, Beijing Sport University, Beijing, China
- Department of Physical Performance, Norwegian School of Sport Sciences, Ullevål Stadion, P.O.Box 4012, 0806 Oslo, Norway
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Jakobsson J, Cotgreave I, Furberg M, Arnberg N, Svensson M. Potential Physiological and Cellular Mechanisms of Exercise That Decrease the Risk of Severe Complications and Mortality Following SARS-CoV-2 Infection. Sports (Basel) 2021; 9:121. [PMID: 34564326 PMCID: PMC8472997 DOI: 10.3390/sports9090121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 08/19/2021] [Accepted: 08/23/2021] [Indexed: 01/08/2023] Open
Abstract
The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has unmasked mankind's vulnerability to biological threats. Although higher age is a major risk factor for disease severity in COVID-19, several predisposing risk factors for mortality are related to low cardiorespiratory and metabolic fitness, including obesity, cardiovascular disease, diabetes, and hypertension. Reaching physical activity (PA) guideline goals contribute to protect against numerous immune and inflammatory disorders, in addition to multi-morbidities and mortality. Elevated levels of cardiorespiratory fitness, being non-obese, and regular PA improves immunological function, mitigating sustained low-grade systemic inflammation and age-related deterioration of the immune system, or immunosenescence. Regular PA and being non-obese also improve the antibody response to vaccination. In this review, we highlight potential physiological, cellular, and molecular mechanisms that are affected by regular PA, increase the host antiviral defense, and may determine the course and outcome of COVID-19. Not only are the immune system and regular PA in relation to COVID-19 discussed, but also the cardiovascular, respiratory, renal, and hormonal systems, as well as skeletal muscle, epigenetics, and mitochondrial function.
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Affiliation(s)
- Johan Jakobsson
- Section of Sports Medicine, Department of Community Medicine and Rehabilitation, Umeå University, 901 87 Umeå, Sweden;
| | - Ian Cotgreave
- Division of Biomaterials and Health, Department of Pharmaceutical and Chemical Safety, Research Institutes of Sweden, 151 36 Södertälje, Sweden;
| | - Maria Furberg
- Department of Clinical Microbiology, Umeå University, 901 87 Umeå, Sweden; (M.F.); (N.A.)
| | - Niklas Arnberg
- Department of Clinical Microbiology, Umeå University, 901 87 Umeå, Sweden; (M.F.); (N.A.)
| | - Michael Svensson
- Section of Sports Medicine, Department of Community Medicine and Rehabilitation, Umeå University, 901 87 Umeå, Sweden;
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Périard JD, Eijsvogels TMH, Daanen HAM. Exercise under heat stress: thermoregulation, hydration, performance implications, and mitigation strategies. Physiol Rev 2021; 101:1873-1979. [PMID: 33829868 DOI: 10.1152/physrev.00038.2020] [Citation(s) in RCA: 151] [Impact Index Per Article: 50.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
A rise in body core temperature and loss of body water via sweating are natural consequences of prolonged exercise in the heat. This review provides a comprehensive and integrative overview of how the human body responds to exercise under heat stress and the countermeasures that can be adopted to enhance aerobic performance under such environmental conditions. The fundamental concepts and physiological processes associated with thermoregulation and fluid balance are initially described, followed by a summary of methods to determine thermal strain and hydration status. An outline is provided on how exercise-heat stress disrupts these homeostatic processes, leading to hyperthermia, hypohydration, sodium disturbances, and in some cases exertional heat illness. The impact of heat stress on human performance is also examined, including the underlying physiological mechanisms that mediate the impairment of exercise performance. Similarly, the influence of hydration status on performance in the heat and how systemic and peripheral hemodynamic adjustments contribute to fatigue development is elucidated. This review also discusses strategies to mitigate the effects of hyperthermia and hypohydration on exercise performance in the heat by examining the benefits of heat acclimation, cooling strategies, and hyperhydration. Finally, contemporary controversies are summarized and future research directions are provided.
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Affiliation(s)
- Julien D Périard
- University of Canberra Research Institute for Sport and Exercise, Bruce, Australia
| | - Thijs M H Eijsvogels
- Department of Physiology, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Hein A M Daanen
- Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
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Chen Y, Yu T. Involvement of p53 in the Responses of Cardiac Muscle Cells to Heat Shock Exposure and Heat Acclimation. J Cardiovasc Transl Res 2020; 13:928-937. [PMID: 32314164 DOI: 10.1007/s12265-020-10003-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 04/07/2020] [Indexed: 11/28/2022]
Abstract
Intense heat stress induces damage to the heart, whereas mild to moderate heat stress protects the heart against subsequent ischemic injury. The mechanisms underlying the detrimental and beneficial effects of heat stress remain unclear. In this study, we investigated the role of p53 in the responses of cardiac muscle cells to acute heat exposure and heat acclimation (HA). Heat exposure increased the levels of caspase and annexin, and levels of cytosolic, nuclear, and mitochondrial p53 protein in H9c2 cells. Pifithrin-α or pifithrin-μ reduced heat-induced apoptotic response in these cells. HA reduced localization of p53 in the mitochondria and improved cell viability during heat exposure. The effects of heat exposure and HA on p53 were further verified in vivo in mouse heart tissue. These results suggest that p53 plays a role in heat-induced apoptosis in cardiac muscle cells. The protective effect of HA against heat injury likely involves a p53-dependent mechanism.
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Affiliation(s)
- Yifan Chen
- Department of Military and Emergency Medicine, Uniformed Services University, 4301 Jones Bridge Road, Bethesda, MD, 20814, USA.
| | - Tianzheng Yu
- Department of Military and Emergency Medicine, Uniformed Services University, 4301 Jones Bridge Road, Bethesda, MD, 20814, USA
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA
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13
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Skattebo Ø, Calbet JAL, Rud B, Capelli C, Hallén J. Contribution of oxygen extraction fraction to maximal oxygen uptake in healthy young men. Acta Physiol (Oxf) 2020; 230:e13486. [PMID: 32365270 PMCID: PMC7540168 DOI: 10.1111/apha.13486] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 04/22/2020] [Accepted: 04/23/2020] [Indexed: 12/16/2022]
Abstract
We analysed the importance of systemic and peripheral arteriovenous O2 difference (
a-v¯O2 difference and a‐vfO2 difference, respectively) and O2 extraction fraction for maximal oxygen uptake (
V˙O2max). Fick law of diffusion and the Piiper and Scheid model were applied to investigate whether diffusion versus perfusion limitations vary with
V˙O2max. Articles (n = 17) publishing individual data (n = 154) on
V˙O2max, maximal cardiac output (
Q˙max; indicator‐dilution or the Fick method),
a-v¯O2 difference (catheters or the Fick equation) and systemic O2 extraction fraction were identified. For the peripheral responses, group‐mean data (articles: n = 27; subjects: n = 234) on leg blood flow (LBF; thermodilution), a‐vfO2 difference and O2 extraction fraction (arterial and femoral venous catheters) were obtained.
Q˙max and two‐LBF increased linearly by 4.9‐6.0 L · min–1 per 1 L · min–1 increase in
V˙O2max (R2 = .73 and R2 = .67, respectively; both P < .001). The
a-v¯O2 difference increased from 118‐168 mL · L–1 from a
V˙O2max of 2‐4.5 L · min–1 followed by a reduction (second‐order polynomial: R2 = .27). After accounting for a hypoxemia‐induced decrease in arterial O2 content with increasing
V˙O2max (R2 = .17; P < .001), systemic O2 extraction fraction increased up to ~90% (
V˙O2max: 4.5 L · min–1) with no further change (exponential decay model: R2 = .42). Likewise, leg O2 extraction fraction increased with
V˙O2max to approach a maximal value of ~90‐95% (R2 = .83). Muscle O2 diffusing capacity and the equilibration index Y increased linearly with
V˙O2max (R2 = .77 and R2 = .31, respectively; both P < .01), reflecting decreasing O2 diffusional limitations and accentuating O2 delivery limitations. In conclusion, although O2 delivery is the main limiting factor to
V˙O2max, enhanced O2 extraction fraction (≥90%) contributes to the remarkably high
V˙O2max in endurance‐trained individuals.
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Affiliation(s)
- Øyvind Skattebo
- Department of Physical Performance Norwegian School of Sport Sciences Oslo Norway
| | - Jose A. L. Calbet
- Department of Physical Performance Norwegian School of Sport Sciences Oslo Norway
- Department of Physical Education and Research Institute of Biomedical and Health Sciences (IUIBS) University of Las Palmas de Gran Canaria Gran Canaria Spain
| | - Bjarne Rud
- Department of Physical Performance Norwegian School of Sport Sciences Oslo Norway
| | - Carlo Capelli
- Department of Physical Performance Norwegian School of Sport Sciences Oslo Norway
- Department of Neurosciences, Biomedicine and Movement Sciences University of Verona Verona Italy
| | - Jostein Hallén
- Department of Physical Performance Norwegian School of Sport Sciences Oslo Norway
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14
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Abstract
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.
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15
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Wingo JE, Ng J, Katica CP, Carter SJ. Fan cooling after cardiovascular drift does not reverse decrements in maximal oxygen uptake during heat stress. Temperature (Austin) 2019; 6:260-270. [PMID: 31608305 DOI: 10.1080/23328940.2019.1657344] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 08/14/2019] [Accepted: 08/14/2019] [Indexed: 01/07/2023] Open
Abstract
Cardiovascular (CV) drift, the progressive increase in heart rate (HR) and decrease in stroke volume (SV) during constant rate, moderate intensity exercise, is related to reduced maximal oxygen uptake (V̇O2max) during heat stress. Once it has already occurred, it is unknown whether the detrimental effects of CV drift on V̇O2max can be reversed. This study tested the hypothesis that fan cooling after CV drift has occurred attenuates decrements in V̇O2max associated with CV drift. Eight men completed a control graded exercise test (GXT) in 22°C to measure V̇O2max. Then on separate, counterbalanced occasions, they completed one 15-min (15MIN) and two 45-min bouts (45NF and 45FAN) of cycling in 35°C, 40% RH at 60% V̇O2max, each immediately followed by a GXT to measure V̇O2max. For one of the 45-min trials (45FAN), fan airflow (4.5 m/s) was directed at participants beginning ~5 min before the GXT and continuing throughout the remainder of exercise. The purpose of the separate 15- and 45-min trials was to measure V̇O2max during the same time interval that CV drift occurred. HR increased (13.8% and 11.4%) and SV decreased (14.4% and 14.1%) for 45NF and 45FAN, respectively; trials were not different (all P > 0.05). Despite a decrease in mean skin temperature of ~1°C with fan use, V̇O2max decreased similarly between conditions (17% vs. 15% for 45NF and 45FAN, P = 0.54). Fan cooling after CV drift was insufficient to reverse the negative consequences of CV drift on V̇O2max after prolonged exercise in a hot environment. Abbreviations: 15MIN: 15-min trial; 45FAN: 45-min, fan trial; 45NF: 45-min, no fan trial; ANOVA: Analysis of variance; CV: Cardiovascular; GXT: Graded exercise test; HR: Heart rate; SV: Stroke volume; T̅b: Mean body temperature; Tre: Rectal temperature; T̅sk: Mean skin temperature; V̇O2max: Maximal oxygen uptake.
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Affiliation(s)
- Jonathan E Wingo
- Department of Kinesiology, University of Alabama, Tuscaloosa, AL, USA
| | - Jason Ng
- Department of Kinesiology, University of Alabama, Tuscaloosa, AL, USA.,Department of Kinesiology, California State University, San Bernardino, CA, USA
| | - Charles P Katica
- Department of Kinesiology, University of Alabama, Tuscaloosa, AL, USA.,Department of Kinesiology, Pacific Lutheran University, Tacoma, WA, USA
| | - Stephen J Carter
- Department of Kinesiology, University of Alabama, Tuscaloosa, AL, USA.,Department of Kinesiology, Indiana University Bloomington, Bloomington, IN, USA
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16
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Sutehall S, Muniz-Pardos B, Bosch AN, Di Gianfrancesco A, Pitsiladis YP. Sports Drinks on the Edge of a New Era. Curr Sports Med Rep 2018; 17:112-116. [PMID: 29629968 DOI: 10.1249/jsr.0000000000000475] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Affiliation(s)
- Shaun Sutehall
- Division of Exercise Science and Sports Medicine, University of Cape Town, Cape Town, SOUTH AFRICA
| | - Borja Muniz-Pardos
- Division of Exercise Science and Sports Medicine, University of Cape Town, Cape Town, SOUTH AFRICA
| | - Andrew N Bosch
- Division of Exercise Science and Sports Medicine, University of Cape Town, Cape Town, SOUTH AFRICA
| | - Alessia Di Gianfrancesco
- Division of Exercise Science and Sports Medicine, University of Cape Town, Cape Town, SOUTH AFRICA
| | - Yannis P Pitsiladis
- Division of Exercise Science and Sports Medicine, University of Cape Town, Cape Town, SOUTH AFRICA.,Division of Exercise Science and Sports Medicine, University of Cape Town, Cape Town, SOUTH AFRICA.,Division of Exercise Science and Sports Medicine, University of Cape Town, Cape Town, SOUTH AFRICA
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17
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Wilhelm EN, González-Alonso J, Chiesa ST, Trangmar SJ, Kalsi KK, Rakobowchuk M. Whole-body heat stress and exercise stimulate the appearance of platelet microvesicles in plasma with limited influence of vascular shear stress. Physiol Rep 2018; 5:5/21/e13496. [PMID: 29122961 PMCID: PMC5688785 DOI: 10.14814/phy2.13496] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 10/13/2017] [Indexed: 01/02/2023] Open
Abstract
Intense, large muscle mass exercise increases circulating microvesicles, but our understanding of microvesicle dynamics and mechanisms inducing their release remains limited. However, increased vascular shear stress is generally thought to be involved. Here, we manipulated exercise‐independent and exercise‐dependent shear stress using systemic heat stress with localized single‐leg cooling (low shear) followed by single‐leg knee extensor exercise with the cooled or heated leg (Study 1, n = 8) and whole‐body passive heat stress followed by cycling (Study 2, n = 8). We quantified femoral artery shear rates (SRs) and arterial and venous platelet microvesicles (PMV–CD41+) and endothelial microvesicles (EMV–CD62E+). In Study 1, mild passive heat stress while one leg remained cooled did not affect [microvesicle] (P ≥ 0.05). Single‐leg knee extensor exercise increased active leg SRs by ~12‐fold and increased arterial and venous [PMVs] by two‐ to threefold, even in the nonexercising contralateral leg (P < 0.05). In Study 2, moderate whole‐body passive heat stress increased arterial [PMV] compared with baseline (mean±SE, from 19.9 ± 1.5 to 35.5 ± 5.4 PMV.μL−1.103, P < 0.05), and cycling with heat stress increased [PMV] further in the venous circulation (from 27.5 ± 2.2 at baseline to 57.5 ± 7.2 PMV.μL−1.103 during cycling with heat stress, P < 0.05), with a tendency for increased appearance of PMV across exercising limbs. Taken together, these findings demonstrate that whole‐body heat stress may increase arterial [PMV], and intense exercise engaging either large or small muscle mass promote PMV formation locally and systemically, with no influence upon [EMV]. Local shear stress, however, does not appear to be the major stimulus modulating PMV formation in healthy humans.
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Affiliation(s)
- Eurico N Wilhelm
- Centre for Human Performance, Exercise, and Rehabilitation, College of Health and Life Sciences, Brunel University London, Uxbridge, United Kingdom
| | - José González-Alonso
- Centre for Human Performance, Exercise, and Rehabilitation, College of Health and Life Sciences, Brunel University London, Uxbridge, United Kingdom.,Division of Sport, Health and Exercise Sciences, Department of Life Sciences, Brunel University London, Uxbridge, United Kingdom
| | - Scott T Chiesa
- Centre for Human Performance, Exercise, and Rehabilitation, College of Health and Life Sciences, Brunel University London, Uxbridge, United Kingdom
| | - Steven J Trangmar
- Centre for Human Performance, Exercise, and Rehabilitation, College of Health and Life Sciences, Brunel University London, Uxbridge, United Kingdom
| | - Kameljit K Kalsi
- Centre for Human Performance, Exercise, and Rehabilitation, College of Health and Life Sciences, Brunel University London, Uxbridge, United Kingdom
| | - Mark Rakobowchuk
- Centre for Human Performance, Exercise, and Rehabilitation, College of Health and Life Sciences, Brunel University London, Uxbridge, United Kingdom .,Faculty of Science, Department of Biological Sciences, Thompson Rivers University, Kamloops, British Columbia, Canada
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18
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Trangmar SJ, Chiesa ST, Kalsi KK, Secher NH, González-Alonso J. Whole body hyperthermia, but not skin hyperthermia, accelerates brain and locomotor limb circulatory strain and impairs exercise capacity in humans. Physiol Rep 2017; 5:5/2/e13108. [PMID: 28108645 PMCID: PMC5269410 DOI: 10.14814/phy2.13108] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 12/08/2016] [Accepted: 12/09/2016] [Indexed: 12/26/2022] Open
Abstract
Cardiovascular strain and hyperthermia are thought to be important factors limiting exercise capacity in heat‐stressed humans, however, the contribution of elevations in skin (Tsk) versus whole body temperatures on exercise capacity has not been characterized. To ascertain their relationships with exercise capacity, blood temperature (TB), oxygen uptake (V̇O2), brain perfusion (MCA Vmean), locomotor limb hemodynamics, and hematological parameters were assessed during incremental cycling exercise with elevated skin (mild hyperthermia; HYPmild), combined core and skin temperatures (moderate hyperthermia; HYPmod), and under control conditions. Both hyperthermic conditions increased Tsk versus control (6.2 ± 0.2°C; P < 0.001), however, only HYPmod increased resting TB, leg blood flow and cardiac output (Q̇), but not MCA Vmean. Throughout exercise, Tsk remained elevated in both hyperthermic conditions, whereas only TB was greater in HYPmod. At exhaustion, oxygen uptake and exercise capacity were reduced in HYPmod in association with lower leg blood flow, MCA Vmean and mean arterial pressure (MAP), but similar maximal heart rate and TB. The attenuated brain and leg perfusion with hyperthermia was associated with a plateau in MCA and two‐legged vascular conductance (VC). Mechanistically, the falling MCA VC was coupled to reductions in PaCO2, whereas the plateau in leg vascular conductance was related to markedly elevated plasma [NA] and a plateau in plasma ATP. These findings reveal that whole‐body hyperthermia, but not skin hyperthermia, compromises exercise capacity in heat‐stressed humans through the early attenuation of brain and active muscle blood flow.
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Affiliation(s)
- Steven J Trangmar
- Centre for Human Performance, Exercise and Rehabilitation, Brunel University London, Uxbridge, United Kingdom
| | - Scott T Chiesa
- Centre for Human Performance, Exercise and Rehabilitation, Brunel University London, Uxbridge, United Kingdom
| | - Kameljit K Kalsi
- Centre for Human Performance, Exercise and Rehabilitation, Brunel University London, Uxbridge, United Kingdom
| | - Niels H Secher
- Centre for Human Performance, Exercise and Rehabilitation, Brunel University London, Uxbridge, United Kingdom.,The Copenhagen Muscle Research Centre, Department of Anaesthesia, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - José González-Alonso
- Centre for Human Performance, Exercise and Rehabilitation, Brunel University London, Uxbridge, United Kingdom
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19
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Trangmar SJ, González-Alonso J. New Insights Into the Impact of Dehydration on Blood Flow and Metabolism During Exercise. Exerc Sport Sci Rev 2017; 45:146-153. [PMID: 28419001 DOI: 10.1249/jes.0000000000000109] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Exercise-induced dehydration can lead to impaired perfusion to multiple regional tissues and organs. We propose that the impact of dehydration on regional blood flow and metabolism is dependent on the extent of the cardiovascular demand imposed by exercise, with the greatest physiological strain seen when approaching cardiovascular and aerobic capacities.
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Affiliation(s)
- Steven J Trangmar
- 1Department of Life Sciences, University of Roehampton, London; and 2Centre for Human Performance, Exercise and Rehabilitation, Brunel University London, Uxbridge, United Kingdom
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20
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Chiesa ST, Bhowruth DJ, Trangmar SJ. Short-term heat therapy: sufficient stimulus for structural vascular adaptations? J Physiol 2017; 595:3667-3668. [PMID: 28568771 DOI: 10.1113/jp274047] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
- Scott T Chiesa
- National Centre for Cardiovascular Preventions and Outcomes (NCCPO), Institute of Cardiovascular Science, University College London, London, UK
| | - Devina J Bhowruth
- National Centre for Cardiovascular Preventions and Outcomes (NCCPO), Institute of Cardiovascular Science, University College London, London, UK
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