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Bai H, Zhao N, Li X, Ding Y, Guo Q, Chen G, Chang G. Whole-genome resequencing identifies candidate genes associated with heat adaptation in chickens. Poult Sci 2024; 103:104139. [PMID: 39127007 DOI: 10.1016/j.psj.2024.104139] [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: 03/17/2024] [Revised: 06/17/2024] [Accepted: 07/25/2024] [Indexed: 08/12/2024] Open
Abstract
The wide distribution and diverse varieties of chickens make them important models for studying genetic adaptation. The aim of this study was to identify genes that alter heat adaptation in commercial chicken breeds by comparing genetic differences between tropical and cold-resistant chickens. We analyzed whole-genome resequencing data of 186 chickens across various regions in Asia, including the following breeds: Bian chickens (B), Dagu chickens (DG), Beijing-You chickens (BY), and Gallus gallus jabouillei from China; Gallus gallus murghi from India; Vietnam native chickens (VN); Thailand native chickens (TN) and Gallus gallus spadiceus from Thailand; and Indonesia native chickens (IN), Gallus gallus gallus, and Gallus gallus bankiva from Indonesia. In total, 5,454,765 SNPs were identified for further analyses. Population genetic structure analysis revealed that each local chicken breed had undergone independent evolution. Additionally, when K = 5, B, BY, and DG chickens shared a common ancestor and exhibited high levels of inbreeding, suggesting that northern cold-resistant chickens are likely the result of artificial selection. In contrast, the runs of homozygosity (ROH) and the ROH-based genomic inbreeding coefficient (FROH) results for IN, TN, and VN chickens showed low levels of inbreeding. Low population differentiation index values indicated low differentiation levels, suggesting low genetic diversity in tropical chickens, implying increased vulnerability to environmental changes, decreased adaptability, and disease resistance. Whole-genome selection sweep analysis revealed 69 candidate genes, including LGR4, G6PC, and NBR1, between tropical and cold-resistant chickens. The genes were further subjected to GO and KEGG enrichment analyses, revealing that most of the genes were primarily enriched in biological synthesis processes, metabolic processes, central nervous system development, ion transmembrane transport, and the Wnt signaling pathway. Our study identified heat adaptation genes and their functions in chickens that primarily affect chickens in high-temperature environments through metabolic pathways. These heat-resistance genes provide a theoretical basis for improving the heat-adaptation capacity of commercial chicken breeds.
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Affiliation(s)
- Hao Bai
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, Institutes of Agricultural Science and Technology Development, The Ministry of Education of China, Yangzhou University, Yangzhou 225009, China
| | - Ning Zhao
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, Institutes of Agricultural Science and Technology Development, The Ministry of Education of China, Yangzhou University, Yangzhou 225009, China; School of Life Sciences, Southwest University, Chongqing 400715, China
| | - Xing Li
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, Institutes of Agricultural Science and Technology Development, The Ministry of Education of China, Yangzhou University, Yangzhou 225009, China; School of Life Sciences, Southwest University, Chongqing 400715, China
| | - Yifan Ding
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, Institutes of Agricultural Science and Technology Development, The Ministry of Education of China, Yangzhou University, Yangzhou 225009, China
| | - Qixin Guo
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, Institutes of Agricultural Science and Technology Development, The Ministry of Education of China, Yangzhou University, Yangzhou 225009, China
| | - Guohong Chen
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, Institutes of Agricultural Science and Technology Development, The Ministry of Education of China, Yangzhou University, Yangzhou 225009, China
| | - Guobin Chang
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, Institutes of Agricultural Science and Technology Development, The Ministry of Education of China, Yangzhou University, Yangzhou 225009, China.
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Deshayes TA, Sodabi DGA, Dubord M, Gagnon D. Shifting focus: Time to look beyond the classic physiological adaptations associated with human heat acclimation. Exp Physiol 2024; 109:335-349. [PMID: 37885125 PMCID: PMC10988689 DOI: 10.1113/ep091207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Accepted: 10/12/2023] [Indexed: 10/28/2023]
Abstract
Planet Earth is warming at an unprecedented rate and our future is now assured to be shaped by the consequences of more frequent hot days and extreme heat. Humans will need to adapt both behaviorally and physiologically to thrive in a hotter climate. From a physiological perspective, countless studies have shown that human heat acclimation increases thermoeffector output (i.e., sweating and skin blood flow) and lowers cardiovascular strain (i.e., heart rate) during heat stress. However, the mechanisms mediating these adaptations remain understudied. Furthermore, several possible benefits of heat acclimation for other systems and functions involved in maintaining health and performance during heat stress remain to be elucidated. This review summarizes recent advances in human heat acclimation, with emphasis on recent studies that (1) advanced our understanding of the mechanisms mediating improved thermoeffector output and (2) investigated adaptations that go beyond those classically associated with heat acclimation. We highlight that these studies have contributed to a better understanding of the integrated physiological responses underlying human heat acclimation while leaving key unanswered questions that will need to be addressed in the future.
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Affiliation(s)
- Thomas A. Deshayes
- Montreal Heart InstituteMontréalCanada
- School of Kinesiology and Exercise ScienceUniversité de MontréalMontréalCanada
| | - Dèwanou Gilles Arnaud Sodabi
- Montreal Heart InstituteMontréalCanada
- School of Kinesiology and Exercise ScienceUniversité de MontréalMontréalCanada
| | - Marianne Dubord
- Montreal Heart InstituteMontréalCanada
- School of Kinesiology and Exercise ScienceUniversité de MontréalMontréalCanada
| | - Daniel Gagnon
- Montreal Heart InstituteMontréalCanada
- School of Kinesiology and Exercise ScienceUniversité de MontréalMontréalCanada
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3
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Yen CL, Petrie MA, Suneja M, Shields RK. Neuromuscular and gene signaling responses to passive whole-body heat stress in young adults. J Therm Biol 2023; 118:103730. [PMID: 37890230 DOI: 10.1016/j.jtherbio.2023.103730] [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: 12/31/2022] [Revised: 09/13/2023] [Accepted: 10/13/2023] [Indexed: 10/29/2023]
Abstract
This study aimed to investigate whether acute passive heat stress 1) decreases muscle Maximal Voluntary Contraction (MVC); 2) increases peripheral muscle fatigue; 3) increases spinal cord excitability, and 4) increases key skeletal muscle gene signaling pathways in skeletal muscle. Examining the biological and physiological markers underlying passive heat stress will assist us in understanding the potential therapeutic benefits. MVCs, muscle fatigue, spinal cord excitability, and gene signaling were examined after control or whole body heat stress in an environmental chamber (heat; 82 °C, 10% humidity for 30 min). Heart Rate (HR), an indicator of stress response, was correlated to muscle fatigue in the heat group (R = 0.59; p < 0.05) but was not correlated to MVC, twitch potentiation, and H reflex suppression. Sixty-one genes were differentially expressed after heat (41 genes >1.5-fold induced; 20 < 0.667 fold repressed). A strong correlation emerged between the session type (control or heat) and principal components (PC1) (R = 0.82; p < 0.005). Cell Signal Transduction, Metabolism, Gene Expression and Transcription, Immune System, DNA Repair, and Metabolism of Proteins were pathway domains with the largest number of genes regulated after acute whole body heat stress. Acute whole-body heat stress may offer a physiological stimulus for people with a limited capacity to exercise.
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Affiliation(s)
- Chu-Ling Yen
- School of Physical Therapy and Graduate Institute of Rehabilitation Science, College of Medicine, Chang Gung University, Taoyuan, Taiwan; Chang Gung Memorial Hospital, Neuroscience Research Center, Linkou, Taoyuan, Taiwan
| | - Michael A Petrie
- Department of Physical Therapy and Rehabilitation Science, Roy and Lucille Carver College of Medicine, The University of Iowa, Medical Education Building, Iowa City, IA, USA
| | - Manish Suneja
- Department of Internal Medicine, Roy and Lucille Carver College of Medicine, The University of Iowa, Iowa City, IA, USA
| | - Richard K Shields
- Department of Physical Therapy and Rehabilitation Science, Roy and Lucille Carver College of Medicine, The University of Iowa, Medical Education Building, Iowa City, IA, USA.
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Mornas A, Brocherie F, Guilhem G, Guillotel A, LE Garrec S, Gouwy R, Gennisson JL, Beuve S, Racinais S. Active Heat Acclimation Does Not Alter Muscle-Tendon Unit Properties. Med Sci Sports Exerc 2023; 55:1076-1086. [PMID: 36719653 DOI: 10.1249/mss.0000000000003129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
PURPOSE Heat acclimation (HA) is recommended before competing in hot and humid conditions. HA has also been recently suggested to increase muscle strength, but its effects on human's muscle and tendon mechanical properties are not yet fully understood. This study investigated the effect of active HA on gastrocnemius medialis (GM) muscle-tendon properties. METHODS Thirty recreationally active participants performed 13 low-intensity cycling sessions, distributed over a 17-d period in hot (HA = ~38°C, ~58% relative humidity; n = 15) or in temperate environment (CON = ~23°C, ~35% relative humidity; n = 15). Mechanical data and high-frame rate ultrasound images were collected during electrically evoked and voluntary contractions pre- and postintervention. Shear modulus was measured at rest in GM, and vertical jump performance was assessed. RESULTS Core temperature decreased from the first to the last session in HA (-0.4°C ± 0.3°C; P = 0.015), while sweat rate increased (+0.4 ± 0.3 L·h -1 ; P = 0.010), suggesting effective HA, whereas no changes were observed in CON (both P ≥ 0.877). Heart rate was higher in HA versus CON and decreased throughout intervention in groups (both P ≤ 0.008), without an interaction effect ( P = 0.733). Muscle-tendon unit properties (i.e., maximal and explosive isometric torque production, contractile properties, voluntary activation, joint and fascicular force-velocity relationship, passive muscle, and active tendon stiffness) and vertical jump performance did not show training ( P ≥ 0.067) or group-training interaction ( P ≥ 0.232) effects. CONCLUSIONS Effective active HA does not alter muscle-tendon properties. Preparing hot and humid conditions with active HA can be envisaged in all sporting disciplines without the risk of impairing muscle performance.
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Affiliation(s)
| | - Franck Brocherie
- Laboratory Sport, Expertise and Performance (EA 7370), French Institute of Sport (INSEP), Paris, FRANCE
| | - Gaël Guilhem
- Laboratory Sport, Expertise and Performance (EA 7370), French Institute of Sport (INSEP), Paris, FRANCE
| | - Arthur Guillotel
- Laboratory Sport, Expertise and Performance (EA 7370), French Institute of Sport (INSEP), Paris, FRANCE
| | | | | | - Jean-Luc Gennisson
- Laboratoire d'Imagerie Biomédicale Multimodale (BioMaps), CEA, CNRS, Inserm, Service Hospitalier Frédéric Joliot, Université Paris-Saclay, Orsay, FRANCE
| | - Steve Beuve
- Laboratoire d'Imagerie Biomédicale Multimodale (BioMaps), CEA, CNRS, Inserm, Service Hospitalier Frédéric Joliot, Université Paris-Saclay, Orsay, FRANCE
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Toro-Román V, Prieto-González I, Siquier-Coll J, Bartolomé I, Grijota FJ, Maynar-Mariño M. Effects of High Temperature Exposure on the Wingate Test Performance in Male University Students. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:4782. [PMID: 36981697 PMCID: PMC10049338 DOI: 10.3390/ijerph20064782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 03/05/2023] [Accepted: 03/06/2023] [Indexed: 06/18/2023]
Abstract
It has been suggested that heat exposure prior to exercise could induce changes in anaerobic exercise. Therefore, the purpose of this study was to observe the effects of high temperature heat exposure prior to an anaerobic test. Twenty-one men (age: 19.76 ± 1.22 years; height: 1.69 ± 0.12 m; weight: 67.89 ± 11.78 kg) voluntarily participated in this investigation. All of them performed two Wingate tests, vertical jump and macronutrient intake control. On the first day, the test was performed under normal environmental conditions. On the second day, it was performed in a similar way, but with previous exposure to heat at high sauna temperatures (15 min; 100 ± 2 °C). There were no differences in the vertical jump and macronutrient intake. However, the results showed an improvement in power (W) (p < 0.05), relative power (W/kg) (p < 0.01) and revolutions per minute (p < 0.05) 10 s after the start of the test. There was also an increase in thigh (p < 0.01) and skin temperature (p < 0.01) with pre-heat exposure. The results obtained suggest that this pre-exercise protocol could improve power in short and intensive actions.
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Affiliation(s)
- Víctor Toro-Román
- Faculty of Sport Sciences, University of Extremadura, Avenida de la Universidad s/n, 10003 Cáceres, Spain; (V.T.-R.)
| | - Isaac Prieto-González
- Faculty of Sport Sciences, University of Extremadura, Avenida de la Universidad s/n, 10003 Cáceres, Spain; (V.T.-R.)
| | - Jesús Siquier-Coll
- SER Research Group, Center of Higher Education Alberta Giménez, Comillas Pontifical University, Costa de Saragossa 16, 07013 Palma Mallorca, Spain
| | - Ignacio Bartolomé
- Department of Sport Science, Faculty of Education, Pontifical University of Salamanca, C/Henry Collet, 52-70, 37007 Salamanca, Spain
| | - Francisco J. Grijota
- Faculty of Life and Nature Sciences, University of Nebrija, Campus La Berzosa, Calle del Hostal, Hoyo de Manzanares, 28248 Madrid, Spain
| | - Marcos Maynar-Mariño
- Faculty of Sport Sciences, University of Extremadura, Avenida de la Universidad s/n, 10003 Cáceres, Spain; (V.T.-R.)
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Gordon RJFH, Moss JN, Castelli F, Reeve T, Diss CE, Tyler CJ, Tillin NA. Heat acclimation reduces the effects of whole-body hyperthermia on knee-extensor relaxation rate, but does not affect voluntary torque production. Eur J Appl Physiol 2023; 123:1067-1080. [PMID: 36637508 PMCID: PMC10119217 DOI: 10.1007/s00421-022-05127-7] [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: 08/05/2022] [Accepted: 12/23/2022] [Indexed: 01/14/2023]
Abstract
PURPOSE This study investigated the effects of acute hyperthermia and heat acclimation (HA) on maximal and rapid voluntary torque production, and their neuromuscular determinants. METHODS Ten participants completed 10 days of isothermic HA (50 °C, 50% rh) and had their knee-extensor neuromuscular function assessed in normothermic and hyperthermic conditions, pre-, after 5 and after 10 days of HA. Electrically evoked twitch and octet (300 Hz) contractions were delivered at rest. Maximum voluntary torque (MVT), surface electromyography (EMG) normalised to maximal M-wave, and voluntary activation (VA) were assessed during brief maximal isometric voluntary contractions. Rate of torque development (RTD) and normalised EMG were measured during rapid voluntary contractions. RESULTS Acute hyperthermia reduced neural drive (EMG at MVT and during rapid voluntary contractions; P < 0.05), increased evoked torques (P < 0.05), and shortened contraction and relaxation rates (P < 0.05). HA lowered resting rectal temperature and heart rate after 10 days (P < 0.05), and increased sweating rate after 5 and 10 days (P < 0.05), no differences were observed between 5 and 10 days. The hyperthermia-induced reduction in twitch half-relaxation was attenuated after 5 and 10 days of HA, but there were no other effects on neuromuscular function either in normothermic or hyperthermic conditions. CONCLUSION HA-induced favourable adaptations to the heat after 5 and 10 days of exposure, but there was no measurable benefit on voluntary neuromuscular function in normothermic or hyperthermic conditions. HA did reduce the hyperthermic-induced reduction in twitch half-relaxation time, which may benefit twitch force summation and thus help preserve voluntary torque in hot environmental conditions.
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Affiliation(s)
- Ralph Joseph Frederick Hills Gordon
- School of Life and Health Life Sciences, University of Roehampton, Holybourne Avenue, London, SW15 4JD, England, UK. .,Faculty of Science and Engineering, School of Psychology & Sport Science, Anglia Ruskin University, East Road, Cambridge, CB1 1PT, UK.
| | - Jodie Natasha Moss
- School of Life and Health Life Sciences, University of Roehampton, Holybourne Avenue, London, SW15 4JD, England, UK
| | - Federico Castelli
- School of Life and Health Life Sciences, University of Roehampton, Holybourne Avenue, London, SW15 4JD, England, UK
| | - Thomas Reeve
- School of Life and Health Life Sciences, University of Roehampton, Holybourne Avenue, London, SW15 4JD, England, UK
| | - Ceri Elen Diss
- School of Life and Health Life Sciences, University of Roehampton, Holybourne Avenue, London, SW15 4JD, England, UK
| | - Christopher James Tyler
- School of Life and Health Life Sciences, University of Roehampton, Holybourne Avenue, London, SW15 4JD, England, UK
| | - Neale Anthony Tillin
- School of Life and Health Life Sciences, University of Roehampton, Holybourne Avenue, London, SW15 4JD, England, UK
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Donnan KJ, Williams EL, Bargh MJ. The effectiveness of heat preparation and alleviation strategies for cognitive performance: A systematic review. Temperature (Austin) 2023; 10:404-433. [PMID: 38130656 PMCID: PMC10732620 DOI: 10.1080/23328940.2022.2157645] [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: 08/24/2022] [Accepted: 12/01/2022] [Indexed: 12/15/2022] Open
Abstract
A range of occupational and performance contexts (e.g. military personnel operations, emergency services, sport) require the critical maintenance of cognitive performance in environmentally challenging environments. Several reviews exist which evaluate the effectiveness of heat preparation strategies to facilitate physical performance. To date, no review has explored the usefulness of heat preparation strategies for cognitive performance. Therefore, this systematic review aimed to evaluate a range of interventions for the maintenance of cognitive performance, during or following active or passive heat exposure. Studies to be included were assessed by two authors reviewing title, abstract, and full-text. Forty articles were identified which met the inclusion criteria. Interventions were categorised into chronic (i.e. acclimation/acclimatisation) and acute strategies (i.e. hydration, cooling, supplementation, psychological). The results indicate that medium-term consecutive heat acclimation may mitigate some cognitive deficits under heat stress, although heat acclimation effectiveness could be influenced by age. Further, pre-cooling appears the most effective cooling method for maintaining cognitive performance under heat stress, although results were somewhat ambiguous. The hydration literature showed that the most effective hydration strategies were those which individualised electrolyte fortified fluid volumes to match for sweat loss. Limited research exploring psychological interventions indicates that motivational self-talk could be facilitative for maintaining cognitive skills following exercise in hot conditions. These findings can be used to help inform strategies for maintaining critical cognitive and decision-making skills in hot environments.
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Affiliation(s)
- Kate J. Donnan
- Department of Sport, Exercise, and Rehabilitation Sciences, University of Hull, Hull, HU6 7RX, UK
| | - Emily L. Williams
- Centre for Human Performance, Carnegie School of Sport, Leeds Beckett University, Leeds, LS6 3QS, UK
| | - Melissa J. Bargh
- School of Sport and Exercise Science, College of Social Science of University of Lincoln, Lincoln, LN6 7TS, UK
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Cognitive Performance Before and Following Habituation to Exercise-Induced Hypohydration of 2 and 4% Body Mass in Physically Active Individuals. Nutrients 2022; 14:nu14050935. [PMID: 35267911 PMCID: PMC8912814 DOI: 10.3390/nu14050935] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 02/17/2022] [Accepted: 02/18/2022] [Indexed: 01/27/2023] Open
Abstract
We investigated the effect of repeated exposures to hypohydration upon cognitive performance. In a randomized crossover design, ten physically active adults completed two 4-week training blocks, one where they maintained euhydration (EUH) and the other where they were water-restricted (DEH) during walking/running at 55% V.O2max, 40 °C. Three sessions per week were performed: (1) 1 h of exercise, (2) exercise until 2% or (3) 4% of body mass has been lost or replaced. Limited to the first and fourth training week, a 12 min walking/running time-trial was completed following the 2 and 4% exercise bouts. Trail making, the Wisconsin card sort, the Stop signal task, Simple visual reaction time and Corsi block-tapping tests were performed immediately following the time-trials. Body mass loss was maintained < 1% with EUH and reached 2.7 and 4.7% with DEH following the time-trials. Except for a lower percentage of correct responses (% accuracy) during the Wisconsin card sort test (p < 0.05) with DEH compared to EUH, no statistically significant decline in cognitive performance was induced by low and moderate levels of hypohydration. Compared to week 1, no statistical differences in cognitive responses were observed after repeated exposures to hypohydration (all p > 0.05). From a practical perspective, the gains in cognitive performance following training to DEH were mostly unclear, but under certain circumstances, were greater than when EUH was maintained. Based on the battery of cognitive tests used in the current study, we conclude that whether physically active individuals are habituated or not to its effect, exercise-induced hypohydration of 2 and 4% has, in general, no or unclear impact on cognitive performance immediately following exercise. These results encourage further research in this area.
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Girard O, Gaoua N, Grantham J, Knez W, Walsh A, Racinais S. Effects of living and working in a hot environment on cognitive function in a quiet and temperature-controlled room: An oil and gas industry study. Temperature (Austin) 2021; 8:372-380. [PMID: 34901319 DOI: 10.1080/23328940.2021.1959289] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
We investigate the effects of seasonal heat stress on cognitive function in outdoor workers. Thirty-nine workers from an oil and gas industry in the Middle-East volunteered for cognitive testing before (5.30 to 7.00 am) and after (3.30 to 5.00 pm) their daily work-shift in hot (August - average daily temperature: ~41°C) and temperate (January - average daily temperature: ~22°C) seasons. While physical activity was reduced in hot compared to temperate season (average normalized acceleration: 96 ± 33 vs. 112 ± 31 × 10-3 g; -12.5 ± 4.7%; P = 0.010), the average core temperature during the work-shift was higher in the hot season (37.4 ± 0.2 vs. 37.2 ± 0.2°C; P = 0.002). Peak core temperature was 38.0 ± 0.1°C and 37.8 ± 0.1°C in hot and temperate seasons, respectively. Cognitive performance did not differ between seasons for tests of recognition memory (P = 0.169), working memory (P = 0.797) and executive function (P = 0.145), independent of testing time. Whereas there was no significant main effect of testing time for tests of recognition memory (P = 0.503) and working memory (P = 0.849), the number of problems solved on the first choice for the executive function test was lower in the afternoon than the morning (-9.2 ± 5.3%; P = 0.039). There was no season × testing time interaction for any cognitive tests (P ≥ 0.145). In the absence of hyperthermia, living and working in a hot environment does not alter cognitive function in oil and gas industry workers tested in a quiet and temperature-controlled room, with reduced clothing encumbrance (relative to work). Conclusions should not be extrapolated to more stressful situations (i.e., thermal stressor present, pronounced dehydration, noise).
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Affiliation(s)
- Olivier Girard
- School of Human Sciences (Exercise and Sport Science), The University of Western Australia, Crawley, Western Australia, Australia.,Research and Scientific Support Department, Aspetar Orthopaedic and Sport Medicine Hospital, Doha, Qatar
| | - Nadia Gaoua
- Research and Scientific Support Department, Aspetar Orthopaedic and Sport Medicine Hospital, Doha, Qatar.,Sport and Exercise Science Research Centre (SESRC), London South Bank University, London, UK
| | - Justin Grantham
- Research and Scientific Support Department, Aspetar Orthopaedic and Sport Medicine Hospital, Doha, Qatar.,RelatePerform, Relate Perform Ltd, Hong Kong
| | - Wade Knez
- Research and Scientific Support Department, Aspetar Orthopaedic and Sport Medicine Hospital, Doha, Qatar
| | - Andrew Walsh
- Research and Scientific Support Department, Aspetar Orthopaedic and Sport Medicine Hospital, Doha, Qatar.,Brisbane Lions Football Club, Brisbane, Queensland, Australia
| | - Sebastien Racinais
- Research and Scientific Support Department, Aspetar Orthopaedic and Sport Medicine Hospital, Doha, Qatar
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Barry H, Gendron P, Gagnon C, Bherer L, Gagnon D. Passive heat acclimation does not modulate processing speed and executive functions during cognitive tasks performed at fixed levels of thermal strain. Appl Physiol Nutr Metab 2021; 47:261-268. [PMID: 34710341 DOI: 10.1139/apnm-2021-0243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
PURPOSE This study evaluated if passive controlled hyperthermia heat acclimation (HA) modulates cognitive performance during passive heat stress. METHODS Eight healthy adults (25 ± 4 years) underwent 7 consecutive days of hot water immersion (core temperature ≥38.6°C) and a 7-day time-control period. On days 1 and 7 of HA, participants performed a digital Stroop test at baseline, when core temperature reached 38.6°C, and after 60 minutes at a core temperature ≥38.6°C to evaluate reaction time during tasks targeting processing speed (reading and counting) and executive functions (inhibition and switching). On days 1 and 7 of the time-control intervention, participants performed the Stroop test with equivalent amounts of time separating each task as for HA. RESULTS During day 1 of HA, reaction time was quicker during the reading (-44 ms [-71, -17], P<0.01) and counting (-39 ms [-76, -2], P=0.04) tasks when rectal temperature reached 38.6°C, but after a further 60 minutes of heat exposure, reaction time only remained quicker during the reading task (-56 ms [-83, -29], P<0.01). Changes in reaction time during heat exposure were unaffected by subsequent HA (interaction, all P≥0.09). CONCLUSION Seven days of HA does not modulate processing speed and executive functions during passive heat exposure. Novelty: - Whether heat acclimation (HA) to improve cognitive performance during heat exposure remains understudied. - We tested the hypothesis that HA modulates reaction time during cognitive tasks performed at matched levels of thermal strain. - Despite classical signs of HA, reaction time during heat exposure was unaffected by HA.
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Affiliation(s)
- Hadiatou Barry
- Montreal Heart Institute, 25465, Montreal, Quebec, Canada.,Universite de Montreal, 5622, Montreal, Quebec, Canada;
| | - Philippe Gendron
- Universite du Quebec a Trois-Rivieres, 14847, DSAP, Trois-Rivieres, Quebec, Canada;
| | | | - Louis Bherer
- Montreal Heart Institute, 25465, Montreal, Quebec, Canada.,Universite de Montreal, 5622, Montreal, Quebec, Canada;
| | - Daniel Gagnon
- Montreal Heart Institute, 25465, Montreal, Canada.,Université de Montréal, 5622, Montreal, Canada;
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11
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Piil JF, Kingma B, Morris NB, Christiansen L, Ioannou LG, Flouris AD, Nybo L. Proposed framework for forecasting heat-effects on motor-cognitive performance in the Summer Olympics. Temperature (Austin) 2021; 8:262-283. [PMID: 34485620 PMCID: PMC8409751 DOI: 10.1080/23328940.2021.1957367] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Heat strain impairs performance across a broad spectrum of sport disciplines. The impeding effects of hyperthermia and dehydration are often ascribed to compromised cardiovascular and muscular functioning, but expert performance also depends on appropriately tuned sensory, motor and cognitive processes. Considering that hyperthermia has implications for central nervous system (CNS) function and fatigue, it is highly relevant to analyze how heat stress forecasted for the upcoming Olympics may influence athletes. This paper proposes and demonstrates the use of a framework combining expected weather conditions with a heat strain and motor-cognitive model to analyze the impact of heat and associated factors on discipline- and scenario-specific performances during the Tokyo 2021 games. We pinpoint that hyperthermia-induced central fatigue may affect prolonged performances and analyze how hyperthermia may impair complex motor-cognitive performance, especially when accompanied by either moderate dehydration or exposure to severe solar radiation. Interestingly, several short explosive performances may benefit from faster cross-bridge contraction velocities at higher muscle temperatures in sport disciplines with little or no negative heat-effect on CNS fatigue or motor-cognitive performance. In the analyses of scenarios and Olympic sport disciplines, we consider thermal impacts on “motor-cognitive factors” such as decision-making, maximal and fine motor-activation as well as the influence on central fatigue and pacing. From this platform, we also provide perspectives on how athletes and coaches can identify risks for their event and potentially mitigate negative motor-cognitive effects for and optimize performance in the environmental settings projected.
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Affiliation(s)
- Jacob Feder Piil
- Department of Nutrition, Exercise and Sports, Section for Integrative Physiology, University of Copenhagen, Copenhagen N, Copenhagen, Denmark
| | - Boris Kingma
- Department of Mechanical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands.,TNO, the Netherlands Organization for Applied Scientific Research, Unit Defense, Safety & Security, Soesterberg, The Netherlands
| | - Nathan B Morris
- Department of Nutrition, Exercise and Sports, Section for Integrative Physiology, University of Copenhagen, Copenhagen N, Copenhagen, Denmark
| | - Lasse Christiansen
- Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Amager and Hvidovre, Hvidovre, Denmark
| | - Leonidas G Ioannou
- FAME Laboratory, School of Exercise Science, University of Thessaly, Thessaly, Greece
| | - Andreas D Flouris
- FAME Laboratory, School of Exercise Science, University of Thessaly, Thessaly, Greece
| | - Lars Nybo
- Department of Nutrition, Exercise and Sports, Section for Integrative Physiology, University of Copenhagen, Copenhagen N, Copenhagen, Denmark
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12
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Osborne JO, Stewart IB, Borg DN, Beagley KW, Buhmann RL, Minett GM. Short-term heat acclimation preserves knee extensor torque but does not improve 20 km self-paced cycling performance in the heat. Eur J Appl Physiol 2021; 121:2761-2772. [PMID: 34148124 PMCID: PMC8416835 DOI: 10.1007/s00421-021-04744-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 06/10/2021] [Indexed: 01/16/2023]
Abstract
Purpose This study investigated the effect of 5 days of heat acclimation training on neuromuscular function, intestinal damage, and 20 km cycling (20TT) performance in the heat. Methods Eight recreationally trained males completed two 5-day training blocks (cycling 60 min day−1 at 50% peak power output) in a counter-balanced, cross-over design, with a 20TT completed before and after each block. Training was conducted in hot (HA: 34.9 ± 0.7 °C, 53 ± 4% relative humidity) or temperate (CON: 22.2 ± 2.6 °C, 65 ± 8% relative humidity) environment. All 20TTs were completed in the heat (35.1 ± 0.5 °C, 51 ± 4% relative humidity). Neuromuscular assessment of knee extensors (5 × 5 s maximum voluntary contraction; MVC) was completed before and after each 20TT and on the first and last days of each training block. Results MVC torque was statistically higher after 5 days of HA training compared to CON (mean difference = 14 N m [95% confidence interval; 6, 23]; p < 0.001; d = 0.77). However, 20TT performance after 5 days of HA training was not statistically different to CON, with a between-conditions mean difference in the completion time of 68 s [95% confidence interval; − 9, 145] (p = 0.076; d = 0.35). Conclusion Short-term heat acclimation training may increase knee extensor strength without changes in central fatigue or intestinal damage. Nevertheless, it is insufficient to improve 20 km self-paced cycling performance in the heat compared to workload-matched training in a temperate environment. These data suggest that recreationally trained athletes gain no worthwhile performance advantage from short-term heat-training before competing in the heat. Supplementary Information The online version contains supplementary material available at 10.1007/s00421-021-04744-y.
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Affiliation(s)
- John O Osborne
- School of Sport Sciences, UiT The Arctic University of Norway, Tromsø, Norway. .,School of Exercise and Nutrition Sciences, Queensland University of Technology (QUT), Brisbane, Australia. .,Institute of Health and Biomedical Innovation, Queensland University of Technology (QUT), Brisbane, Australia.
| | - Ian B Stewart
- School of Exercise and Nutrition Sciences, Queensland University of Technology (QUT), Brisbane, Australia.,Institute of Health and Biomedical Innovation, Queensland University of Technology (QUT), Brisbane, Australia
| | - David N Borg
- School of Exercise and Nutrition Sciences, Queensland University of Technology (QUT), Brisbane, Australia.,Institute of Health and Biomedical Innovation, Queensland University of Technology (QUT), Brisbane, Australia.,The Hopkins Centre, Menzies Health Institute Queensland, Griffith University, Brisbane, Australia
| | - Kenneth W Beagley
- Institute of Health and Biomedical Innovation, Queensland University of Technology (QUT), Brisbane, Australia.,School of Biomedical Sciences, Queensland University of Technology (QUT), Brisbane, Australia
| | - Robert L Buhmann
- School of Health and Sport Sciences, University of the Sunshine Coast, Maroochydore, Australia
| | - Geoffrey M Minett
- School of Exercise and Nutrition Sciences, Queensland University of Technology (QUT), Brisbane, Australia.,Institute of Health and Biomedical Innovation, Queensland University of Technology (QUT), Brisbane, Australia
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13
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Bartolomé I, Siquier-Coll J, Pérez-Quintero M, Robles-Gil MC, Muñoz D, Maynar-Mariño M. Effect of Handgrip Training in Extreme Heat on the Development of Handgrip Maximal Isometric Strength among Young Males. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18105240. [PMID: 34069110 PMCID: PMC8156655 DOI: 10.3390/ijerph18105240] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 05/09/2021] [Accepted: 05/11/2021] [Indexed: 12/04/2022]
Abstract
The aim of this study was to evaluate the acute and adaptive effects of passive extreme heat (100 ± 3 °C) exposition in combination with a strength training protocol on maximal isometric handgrip strength. Fifty-four untrained male university students participated in this investigation. Twenty-nine formed the control group (NG) and 25 the heat-exposed group (HG). All the participants performed a 3-week isotonic handgrip strength training program twice a week with a training volume of 10 series of 10 repetitions with 45-s rest between series, per session. All the subjects only trained their right hand, leaving their left hand untrained. HG performed the same training protocol in hot (100 ± 3 °C) conditions in a dry sauna. Maximal isometric handgrip strength was evaluated each training day before and after the session. NG participants did not experience any modifications in either hand by the end of the study while HG increased maximal strength values in both hands (p < 0.05), decreased the difference between hands (p < 0.05), and recorded higher values than the controls in the trained (p < 0.05) and untrained (p < 0.01) hands after the intervention period. These changes were not accompanied by any modification in body composition in either group. The performance of a unilateral isotonic handgrip strength program in hot conditions during the three weeks induced an increase in maximal isometric handgrip strength in both hands without modifications to bodyweight or absolute body composition.
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Affiliation(s)
- Ignacio Bartolomé
- Department of Physiology, School of Sport Sciences, University of Extremadura, 10003 Cáceres, Spain; (I.B.); (M.P.-Q.); (M.M.-M.)
| | - Jesús Siquier-Coll
- Movement, Brain and Health Research Group (MOBhE), Center of Higher Education Alberta Giménez, Comillas Pontifical University, 07013 Palma de Mallorca, Spain
- Correspondence:
| | - Mario Pérez-Quintero
- Department of Physiology, School of Sport Sciences, University of Extremadura, 10003 Cáceres, Spain; (I.B.); (M.P.-Q.); (M.M.-M.)
| | - María Concepción Robles-Gil
- Department of Didactics of Musical, Plastic and Corporal Expression, School of Teacher Training, University of Extremadura, 10003 Cáceres, Spain; (M.C.R.-G.); (D.M.)
| | - Diego Muñoz
- Department of Didactics of Musical, Plastic and Corporal Expression, School of Teacher Training, University of Extremadura, 10003 Cáceres, Spain; (M.C.R.-G.); (D.M.)
| | - Marcos Maynar-Mariño
- Department of Physiology, School of Sport Sciences, University of Extremadura, 10003 Cáceres, Spain; (I.B.); (M.P.-Q.); (M.M.-M.)
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14
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Wallace PJ, Schultz Martins R, Scott JS, Steele SW, Greenway MJ, Cheung SS. The effects of acute dopamine reuptake inhibition on cognitive function during passive hyperthermia. Appl Physiol Nutr Metab 2020; 46:511-520. [PMID: 33232172 DOI: 10.1139/apnm-2020-0869] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Dopamine activity can modulate physical performance in the heat, but less is known about its effects on cognition during thermal stress. Twelves males completed a randomized, double-blinded protocol consisting of oral ingestion of 20 mg of methylphenidate (MPH) or placebo (lactose pill) during passive heating using a water-perfused suit (water temperature ∼49 °C). To identify the impact of peripheral versus central thermal strain, a cognitive test battery was completed at 4 different thermal states: baseline (BASE; 37.2 ± 0.6 °C core, 32.9 ± 0.7 °C skin), neutral core-hot skin (NC-HS; 37.2 ± 0.3 °C, 37.4 ± 0.3 °C), hyperthermic core-hot skin (HC-HS; 38.7 ± 0.4 °C, 38.7 ± 0.2 °C), and hyperthermic core-cooled skin (HC-CS; 38.5 ± 0.4 °C, 35.1 ± 0.8 °C). The cognitive test battery consisted of the 2-back task (i.e., working memory), set-shifting (i.e., executive function), Groton Maze Learning Task (i.e., executive function) and detection task (i.e., psychomotor processing). MPH led to significantly higher heart rates (∼5-15 b·min-1) at BASE, NC-HS, and HC-HS (all p < 0.05). There were no significant differences in the number of errors made on each task (all p < 0.05). Participants were significantly faster (p < 0.05) on the set-shifting task in the HC-HS timepoint, irrespective of drug condition (p > 0.05). In summary, we demonstrated that 20 mg of MPH did not significantly alter cognitive function during either normothermia or moderate hyperthermia. Novelty: Twenty milligrams of MPH did not significantly alter cognitive function during passive heat stress. MPH led to significant higher heart rates (∼5-15 b·min-1) in thermoneutral and during passive heat stress. Future studies are needed to determine the mechanisms of why MPH improves physical but not cognitive performance during heat stress.
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Affiliation(s)
- Phillip J Wallace
- Environmental Ergonomics Laboratory, Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada
| | - Ricardo Schultz Martins
- Environmental Ergonomics Laboratory, Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada
| | - Jake S Scott
- Environmental Ergonomics Laboratory, Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada
| | - Scott W Steele
- Environmental Ergonomics Laboratory, Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada
| | - Mathew J Greenway
- Department of Family Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Stephen S Cheung
- Environmental Ergonomics Laboratory, Department of Kinesiology, Brock University, St. Catharines, Ontario, Canada
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15
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Ko Y, Kang J, Seol SH, Lee JY. Effectiveness of skin-heating using a water-perfused suit as passive and post-exercise heat acclimation strategies. J Therm Biol 2020; 93:102703. [PMID: 33077124 DOI: 10.1016/j.jtherbio.2020.102703] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 08/14/2020] [Accepted: 08/15/2020] [Indexed: 11/26/2022]
Abstract
The purpose of the present study was to evaluate the effectiveness of passive and post-exercise heat acclimation strategies through directly heating the skin with a water-perfused suit. Nineteen young males participated in the heat acclimation (HA) protocols for 10 days, which were conducted at an air temperature of 33oC with 60%RH. The exercise-only condition (N = 6) conducted 1-h treadmill walking (6 km·h-1) followed by 1-h rest. The post-exercise passive-heating condition (N = 6) wore the suit (inflow water temperature 44.2oC) for 1-h after 1-h walking. The passive-heating condition (N = 7) donned the suit for 2 h. Heat tolerance tests (leg immersion in 42oC water for 60 min) were conducted before and after the training to evaluate changes due to the 10-day intervention. Reflecting that suit-wearing for 10 days as both passive and post-exercise HA strategies can effectively induce adaptive changes, significant interaction effects appeared in: increase or decrease in mean skin temperature (P < 0.05) and elevation in whole-body sweat rate (P < 0.05). Reduction in rectal temperature (P < 0.05) and blood pressure (P < 0.05) were found most prominently in the passive-heating condition. These results indicate that this new method of heat acclimation training, donning a skin-heating water-perfused suit, can generate thermoregulatory benefits. The passive HA intervention could be applied to individuals for whom doing exercise regularly are not feasible.
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Affiliation(s)
- Yelin Ko
- College of Human Ecology, Seoul National University, South Korea
| | - Juho Kang
- College of Human Ecology, Seoul National University, South Korea; Department of Physical Education, Seoul National University, South Korea
| | - Seon-Hong Seol
- College of Human Ecology, Seoul National University, South Korea
| | - Joo-Young Lee
- College of Human Ecology, Seoul National University, South Korea; Research Institute of Human Ecology, Seoul National University, South Korea.
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16
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Trachsel LD, Barry H, Gravel H, Behzadi P, Henri C, Gagnon D. Cardiac function during heat stress: impact of short-term passive heat acclimation. Am J Physiol Heart Circ Physiol 2020; 319:H753-H764. [DOI: 10.1152/ajpheart.00407.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A lower heart rate during heat exposure is a classic marker of heat acclimation (HA). It remains unknown if improved cardiac function contributes to this response. A 7-day passive HA protocol did not alter cardiac systolic function during passive heating, whereas it improved some indexes of diastolic function in young adults. Nonetheless, heart rate during heating was unaffected by HA. These results suggest that passive HA induces limited adaptations in cardiac function during passive heating.
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Affiliation(s)
- Lukas D. Trachsel
- Cardiovascular Prevention and Rehabilitation Center, Montreal Heart Institute, Montreal, Canada
- Department of Medicine, Université de Montréal, Montreal, Canada
- University Clinic for Cardiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Hadiatou Barry
- Cardiovascular Prevention and Rehabilitation Center, Montreal Heart Institute, Montreal, Canada
- Department of Pharmacology and Physiology, Université de Montréal, Montreal, Canada
| | - Hugo Gravel
- Cardiovascular Prevention and Rehabilitation Center, Montreal Heart Institute, Montreal, Canada
- Department of Pharmacology and Physiology, Université de Montréal, Montreal, Canada
| | - Parya Behzadi
- Cardiovascular Prevention and Rehabilitation Center, Montreal Heart Institute, Montreal, Canada
- Department of Pharmacology and Physiology, Université de Montréal, Montreal, Canada
| | - Christine Henri
- Department of Medicine, Université de Montréal, Montreal, Canada
- Research Centre, Montreal Heart Institute, Montreal, Canada
| | - Daniel Gagnon
- Cardiovascular Prevention and Rehabilitation Center, Montreal Heart Institute, Montreal, Canada
- Department of Pharmacology and Physiology, Université de Montréal, Montreal, Canada
- Research Centre, Montreal Heart Institute, Montreal, Canada
- School of Human Kinetics and Exercise Science, Université de Montréal, Montreal, Canada
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17
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Muscle temperature kinetics and thermoregulatory responses to 42 °C hot-water immersion in healthy males and females. Eur J Appl Physiol 2020; 120:2611-2624. [DOI: 10.1007/s00421-020-04482-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Accepted: 08/21/2020] [Indexed: 02/06/2023]
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18
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Ihsan M, Périard JD, Racinais S. Integrating Heat Training in the Rehabilitation Toolbox for the Injured Athlete. Front Physiol 2019; 10:1488. [PMID: 31920696 PMCID: PMC6917657 DOI: 10.3389/fphys.2019.01488] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 11/21/2019] [Indexed: 11/13/2022] Open
Affiliation(s)
- Mohammed Ihsan
- Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Qatar
| | - Julien D Périard
- Research Institute for Sport and Exercise, University of Canberra, Canberra, ACT, Australia
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19
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Martin K, McLeod E, Périard J, Rattray B, Keegan R, Pyne DB. The Impact of Environmental Stress on Cognitive Performance: A Systematic Review. HUMAN FACTORS 2019; 61:1205-1246. [PMID: 31002273 DOI: 10.1177/0018720819839817] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
OBJECTIVE In this review, we detail the impact of environmental stress on cognitive and military task performance and highlight any individual characteristics or interventions which may mitigate any negative effect. BACKGROUND Military personnel are often deployed in regions markedly different from their own, experiencing hot days, cold nights, and trips both above and below sea level. In spite of these stressors, high-level cognitive and operational performance must be maintained. METHOD A systematic review of the electronic databases Medline (PubMed), EMBASE (Scopus), PsycINFO, and Web of Science was conducted from inception up to September 2018. Eligibility criteria included a healthy human cohort, an outcome of cognition or military task performance and assessment of an environmental condition. RESULTS The search returned 113,850 records, of which 124 were included in the systematic review. Thirty-one studies examined the impact of heat stress on cognition; 20 of cold stress; 59 of altitude exposure; and 18 of being below sea level. CONCLUSION The severity and duration of exposure to the environmental stressor affects the degree to which cognitive performance can be impaired, as does the complexity of the cognitive task and the skill or familiarity of the individual performing the task. APPLICATION Strategies to improve cognitive performance in extreme environmental conditions should focus on reducing the magnitude of the physiological and perceptual disturbance caused by the stressor. Strategies may include acclimatization and habituation, being well skilled on the task, and reducing sensations of thermal stress with approaches such as head and neck cooling.
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Affiliation(s)
- Kristy Martin
- University of Canberra, Australian Capital Territory, Australia
| | - Emily McLeod
- University of Canberra, Australian Capital Territory, Australia
| | - Julien Périard
- University of Canberra, Australian Capital Territory, Australia
| | - Ben Rattray
- University of Canberra, Australian Capital Territory, Australia
| | - Richard Keegan
- University of Canberra, Australian Capital Territory, Australia
| | - David B Pyne
- University of Canberra, Australian Capital Territory, Australia
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20
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Gibson OR, James CA, Mee JA, Willmott AG, Turner G, Hayes M, Maxwell NS. Heat alleviation strategies for athletic performance: A review and practitioner guidelines. Temperature (Austin) 2019; 7:3-36. [PMID: 32166103 PMCID: PMC7053966 DOI: 10.1080/23328940.2019.1666624] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 09/06/2019] [Accepted: 09/08/2019] [Indexed: 12/19/2022] Open
Abstract
International competition inevitably presents logistical challenges for athletes. Events such as the Tokyo 2020 Olympic Games require further consideration given historical climate data suggest athletes will experience significant heat stress. Given the expected climate, athletes face major challenges to health and performance. With this in mind, heat alleviation strategies should be a fundamental consideration. This review provides a focused perspective of the relevant literature describing how practitioners can structure male and female athlete preparations for performance in hot, humid conditions. Whilst scientific literature commonly describes experimental work, with a primary focus on maximizing magnitudes of adaptive responses, this may sacrifice ecological validity, particularly for athletes whom must balance logistical considerations aligned with integrating environmental preparation around training, tapering and travel plans. Additionally, opportunities for sophisticated interventions may not be possible in the constrained environment of the athlete village or event arenas. This review therefore takes knowledge gained from robust experimental work, interprets it and provides direction on how practitioners/coaches can optimize their athletes' heat alleviation strategies. This review identifies two distinct heat alleviation themes that should be considered to form an individualized strategy for the athlete to enhance thermoregulatory/performance physiology. First, chronic heat alleviation techniques are outlined, these describe interventions such as heat acclimation, which are implemented pre, during and post-training to prepare for the increased heat stress. Second, acute heat alleviation techniques that are implemented immediately prior to, and sometimes during the event are discussed. Abbreviations: CWI: Cold water immersion; HA: Heat acclimation; HR: Heart rate; HSP: Heat shock protein; HWI: Hot water immersion; LTHA: Long-term heat acclimation; MTHA: Medium-term heat acclimation; ODHA: Once-daily heat acclimation; RH: Relative humidity; RPE: Rating of perceived exertion; STHA: Short-term heat acclimation; TCORE: Core temperature; TDHA: Twice-daily heat acclimation; TS: Thermal sensation; TSKIN: Skin temperature; V̇O2max: Maximal oxygen uptake; WGBT: Wet bulb globe temperature.
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Affiliation(s)
- Oliver R. Gibson
- Centre for Human Performance, Exercise and Rehabilitation (CHPER), Division of Sport, Health and Exercise Sciences, Brunel University London, Uxbridge, UK
| | - Carl A. James
- Institut Sukan Negara (National Sports Institute), Kuala Lumpur, Malaysia
| | - Jessica A. Mee
- School of Sport and Exercise Sciences, University of Worcester, Worcester, UK
| | - Ashley G.B. Willmott
- Cambridge Centre for Sport and Exercise Sciences, Anglia Ruskin University, Cambridge, UK
| | - Gareth Turner
- Bisham Abbey National High-Performance Centre, English Institute of Sport, EIS Performance Centre, Marlow, UK
| | - Mark Hayes
- Environmental Extremes Laboratory, School of Sport and Service Management, University of Brighton, Eastbourne, UK
| | - Neil S. Maxwell
- Environmental Extremes Laboratory, School of Sport and Service Management, University of Brighton, Eastbourne, UK
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21
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Heat Acclimation Does Not Protect Trained Males from Hyperthermia-Induced Impairments in Complex Task Performance. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:ijerph16050716. [PMID: 30823366 PMCID: PMC6427404 DOI: 10.3390/ijerph16050716] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 02/22/2019] [Accepted: 02/25/2019] [Indexed: 01/01/2023]
Abstract
This study evaluated if adaptation to environmental heat stress can counteract the negative effects of hyperthermia on complex motor performance. Thirteen healthy, trained males completed 28 days of heat acclimation with 1 h daily exercise exposure to environmental heat (39.4 ± 0.3 °C and 27.0 ± 1.0% relative humidity). Following comprehensive familiarization, the participants completed motor-cognitive testing before acclimation, as well as after 14 and 28 days of training in the heat. On all three occasions, the participants were tested, at baseline (after ~15 min passive heat exposure) and following exercise-induced hyperthermia which provoked an increase in core temperature of 2.8 ± 0.1 °C (similar across days). Both cognitively dominated test scores and motor performance were maintained during passive heat exposure (no reduction or difference between day 0, 14, and 28 compared to cool conditions). In contrast, complex motor task performance was significantly reduced in hyperthermic conditions by 9.4 ± 3.4% at day 0; 15.1 ± 5.0% at day 14, and 13.0 ± 4.8% at day 28 (all p < 0.05 compared to baseline but not different across days). These results let us conclude that heat acclimation cannot protect trained males from being negatively affected by hyperthermia when they perform complex tasks relying on a combination of cognitive performance and motor function.
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22
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Enhancement of Exercise Performance by 48 Hours, and 15-Day Supplementation with Mangiferin and Luteolin in Men. Nutrients 2019; 11:nu11020344. [PMID: 30736383 PMCID: PMC6412949 DOI: 10.3390/nu11020344] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 01/26/2019] [Accepted: 01/29/2019] [Indexed: 12/27/2022] Open
Abstract
The natural polyphenols mangiferin and luteolin have free radical-scavenging properties, induce the antioxidant gene program and down-regulate the expression of superoxide-producing enzymes. However, the effects of these two polyphenols on exercise capacity remains mostly unknown. To determine whether a combination of luteolin (peanut husk extract containing 95% luteolin, PHE) and mangiferin (mango leave extract (MLE), Zynamite®) at low (PHE: 50 mg/day; and 140 mg/day of MLE containing 100 mg of mangiferin; L) and high doses (PHE: 100 mg/day; MLE: 420 mg/day; H) may enhance exercise performance, twelve physically active men performed incremental exercise to exhaustion, followed by sprint and endurance exercise after 48 h (acute effects) and 15 days of supplementation (prolonged effects) with polyphenols or placebo, following a double-blind crossover design. During sprint exercise, mangiferin + luteolin supplementation enhanced exercise performance, facilitated muscle oxygen extraction, and improved brain oxygenation, without increasing the VO₂. Compared to placebo, mangiferin + luteolin increased muscle O₂ extraction during post-exercise ischemia, and improved sprint performance after ischemia-reperfusion likely by increasing glycolytic energy production, as reflected by higher blood lactate concentrations after the sprints. Similar responses were elicited by the two doses tested. In conclusion, acute and prolonged supplementation with mangiferin combined with luteolin enhances performance, muscle O₂ extraction, and brain oxygenation during sprint exercise, at high and low doses.
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23
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Heathcote SL, Hassmén P, Zhou S, Stevens CJ. Passive Heating: Reviewing Practical Heat Acclimation Strategies for Endurance Athletes. Front Physiol 2018; 9:1851. [PMID: 30618849 PMCID: PMC6306444 DOI: 10.3389/fphys.2018.01851] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 12/07/2018] [Indexed: 11/13/2022] Open
Abstract
Heat acclimation protocols—both active and passive—have been employed by athletes in an effort to attenuate the detrimental effects of heat stress on physical capacities and sports performance. Active strategies have been extensively reviewed, but have various practical and economic limitations. The purpose of this review was therefore to provide an overview of the passive strategies that have received less attention, yet may be more practical or economically viable; recommendations for athletes are also provided. With a systematic search of the relevant databases ending in June 2018, 16 articles on passive heat acclimation that met the inclusion criteria were included in the review. The review highlighted that passive heat acclimation strategies can successfully induce heat adaptations, evident by reports of improved exercise performance, thermoregulatory, cardiovascular, and perceptual responses accompanying such interventions. Based on the review it is apparent that the use of sauna, hot-water immersion and environmental chambers may be used to provide heat stress under passive conditions, for the purpose of acclimation. To maximize the thermoregulatory-adaptive responses, exercise bouts should be employed prior to passive heat stress, rather than passive heating alone, with a minimal delay between exercise and the application of heat stress. Heating bouts should have a minimum duration of 30 min per session and be employed on consecutive days, when possible, with a minimum of 6–7 exposures to induce adaptation. This review identified that information regarding the magnitude of performance changes that can occur, as well as the perceptual responses to passive heating protocols is limited. Future research should investigate the use of passive heat exposures before and/or after repeated heat training sessions, to assess if a further boost to heat adaptation can be achieved with this strategy.
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Affiliation(s)
- Storme L Heathcote
- School of Health and Human Sciences, Southern Cross University, Lismore, NSW, Australia.,Centre for Athlete Development, Experience & Performance, Southern Cross University, Coffs Harbour, NSW, Australia
| | - Peter Hassmén
- School of Health and Human Sciences, Southern Cross University, Lismore, NSW, Australia
| | - Shi Zhou
- School of Health and Human Sciences, Southern Cross University, Lismore, NSW, Australia
| | - Christopher J Stevens
- School of Health and Human Sciences, Southern Cross University, Lismore, NSW, Australia.,Centre for Athlete Development, Experience & Performance, Southern Cross University, Coffs Harbour, NSW, Australia
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Willmott AGB, Gibson OR, James CA, Hayes M, Maxwell NS. Physiological and perceptual responses to exercising in restrictive heat loss attire with use of an upper-body sauna suit in temperate and hot conditions. Temperature (Austin) 2018; 5:162-174. [PMID: 30377634 DOI: 10.1080/23328940.2018.1426949] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 01/08/2018] [Indexed: 10/18/2022] Open
Abstract
The aim of this experiment was to quantify physiological and perceptual responses to exercise with and without restrictive heat loss attire in hot and temperate conditions. Ten moderately-trained individuals (mass; 69.44±7.50 kg, body fat; 19.7±7.6%) cycled for 30-mins (15-mins at 2 W.kg-1 then 15-mins at 1 W.kg-1) under four experimental conditions; temperate (TEMP, 22°C/45%), hot (HOT, 45°C/20%) and, temperate (TEMPSUIT, 22°C/45%) and hot (HOTSUIT, 45°C/20%) whilst wearing an upper-body "sauna suit". Core temperature changes were higher (P<0.05) in TEMPSUIT (+1.7±0.4°C.hr-1), HOT (+1.9±0.5°C.hr-1) and HOTSUIT (+2.3±0.5°C.hr-1) than TEMP (+1.3±0.3°C.hr-1). Skin temperature was higher (P<0.05) in HOT (36.53±0.93°C) and HOTSUIT (37.68±0.68°C) than TEMP (33.50±1.77°C) and TEMPSUIT (33.41±0.70°C). Sweat rate was greater (P<0.05) in TEMPSUIT (0.89±0.24 L.hr-1), HOT (1.14±0.48 L.hr-1) and HOTSUIT (1.51±0.52 L.hr-1) than TEMP (0.56±0.27 L.hr-1). Peak heart rate was higher (P<0.05) in TEMPSUIT (155±23 b.min-1), HOT (163±18 b.min-1) and HOTSUIT (171±18 b.min-1) than TEMP (151±20 b.min-1). Thermal sensation and perceived exertion were greater (P<0.05) in TEMPSUIT (5.8±0.5 and 14±1), HOT (6.4±0.5 and 15±1) and HOTSUIT (7.1±0.5 and 16±1) than TEMP (5.3±0.5 and 14±1). Exercising in an upper-body sauna suit within temperate conditions induces a greater physiological strain and evokes larger sweat losses compared to exercising in the same conditions, without restricting heat loss. In hot conditions, wearing a sauna suit increases physiological and perceptual strain further, which may accelerate the stimuli for heat adaptation and improve HA efficiency.
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Affiliation(s)
| | - Oliver R Gibson
- Environmental Extremes Laboratory, University of Brighton, Eastbourne, UK.,Centre for Human Performance, Exercise and Rehabilitation, Brunel University London, Uxbridge, UK
| | - Carl A James
- Environmental Extremes Laboratory, University of Brighton, Eastbourne, UK.,National Sports Institute, Institut Sukan Negara, National Sport Complex, Bukit Jalil, 57000 Kuala Lumpur, Malaysia
| | - Mark Hayes
- Environmental Extremes Laboratory, University of Brighton, Eastbourne, UK
| | - Neil S Maxwell
- Environmental Extremes Laboratory, University of Brighton, Eastbourne, UK
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25
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Leicht AS, Halliday A, Sinclair WH, D'Auria S, Buchheit M, Kenny GP, Stanley J. Heart rate variability responses to acute and repeated postexercise sauna in trained cyclists. Appl Physiol Nutr Metab 2018; 43:704-710. [PMID: 29444412 DOI: 10.1139/apnm-2017-0581] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Short- to medium-term (i.e., 4-14 days) heating protocols induce physiological adaptations including improved cardiac autonomic modulations, as assessed using heart rate variability, which may contribute to greater exercise performance. Whether similar cardiac autonomic changes occur during an intense heating protocol (sauna) reported to increase plasma volume in athletes remains to be confirmed. This study examined changes in heart rate and its variability during a single extreme heat (sauna) exposure and repeated exposures in athletes. Six well-trained male cyclists undertook sauna bathing (30 min, 87 °C, 11% relative humidity) immediately after normal training over 10 consecutive days. Heart rate recordings were obtained during each sauna bout. Heart rate and its variability (natural logarithm of root mean square of successive differences, lnRMSSD) were analysed during 10-min periods within the first bout, and changes in heart rate and lnRMSSD were analysed during each bout via magnitude-based inferences. During the first sauna bout, heart rate was almost certainly increased (∼32%, effect size 1.68) and lnRMSSD was almost certainly reduced (∼62%, effect size -5.21) from the first to the last 10-min period, indicating reduced parasympathetic and (or) enhanced sympathetic modulations. Acute exposure to extreme heat stress via sauna produced alterations in heart rate and cardiac autonomic modulations with successive postexercise heat exposures producing unclear changes over a 10-day period. The physiological benefits of intense heating via sauna on cardiac control in athletes remain to be elucidated.
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Affiliation(s)
- Anthony S Leicht
- a Sport and Exercise Science, James Cook University, Townsville, 4811, Australia
| | - Aaron Halliday
- a Sport and Exercise Science, James Cook University, Townsville, 4811, Australia
| | - Wade H Sinclair
- a Sport and Exercise Science, James Cook University, Townsville, 4811, Australia
| | - Shaun D'Auria
- b Performance Science, Queensland Academy of Sport, Brisbane, 4111, Australia
| | - Martin Buchheit
- c Sport Science Unit, Myorobie Association, Montvalezan, 73700, France
| | - Glen P Kenny
- d Human and Environmental Physiology Research Unit, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Jamie Stanley
- e Physiology Department, South Australian Sports Institute, Adelaide, 5025, Australia
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Racinais S, Cocking S, Périard JD. Sports and environmental temperature: From warming-up to heating-up. Temperature (Austin) 2017; 4:227-257. [PMID: 28944269 DOI: 10.1080/23328940.2017.1356427] [Citation(s) in RCA: 61] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 07/09/2017] [Accepted: 07/09/2017] [Indexed: 01/22/2023] Open
Abstract
Most professional and recreational athletes perform pre-conditioning exercises, often collectively termed a 'warm-up' to prepare for a competitive task. The main objective of warming-up is to induce both temperature and non-temperature related responses to optimize performance. These responses include increasing muscle temperature, initiating metabolic and circulatory adjustments, and preparing psychologically for the upcoming task. However, warming-up in hot and/or humid ambient conditions increases thermal and circulatory strain. As a result, this may precipitate neuromuscular and cardiovascular impairments limiting endurance capacity. Preparations for competing in the heat should include an acclimatization regimen. Athletes should also consider cooling interventions to curtail heat gain during the warm-up and minimize dehydration. Indeed, although it forms an important part of the pre-competition preparation in all environmental conditions, the rise in whole-body temperature should be limited in hot environments. This review provides recommendations on how to build an effective warm-up following a 3 stage RAMP model (Raise, Activate and Mobilize, Potentiate), including general and context specific exercises, along with dynamic flexibility work. In addition, this review provides suggestion to manipulate the warm-up to suit the demands of competition in hot environments, along with other strategies to avoid heating-up.
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Affiliation(s)
- Sébastien Racinais
- Aspetar Orthopaedic and Sports Medicine Hospital, Athlete Health and Performance Research Centre, Doha, Qatar.,French Institute of Sport (INSEP), Laboratory Sport, Expertise and Performance (EA 7370), Paris, France
| | - Scott Cocking
- Aspetar Orthopaedic and Sports Medicine Hospital, Athlete Health and Performance Research Centre, Doha, Qatar.,Research Institute for Sport and Exercise Science, Liverpool John Moores University, United Kingdom
| | - Julien D Périard
- Aspetar Orthopaedic and Sports Medicine Hospital, Athlete Health and Performance Research Centre, Doha, Qatar.,University of Canberra, Research Institute for Sport and Exercise, Canberra, Australia
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