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Liu S, Wen D, Feng C, Yu C, Gu Z, Wang L, Zhang Z, Li W, Wu S, Liu Y, Duan C, Zhuang R, Xue L. Alteration of gut microbiota after heat acclimation may reduce organ damage by regulating immune factors during heat stress. Front Microbiol 2023; 14:1114233. [PMID: 36910226 PMCID: PMC9995595 DOI: 10.3389/fmicb.2023.1114233] [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: 12/02/2022] [Accepted: 02/06/2023] [Indexed: 02/25/2023] Open
Abstract
Introduction Heat-related illnesses can lead to morbidity, which are anticipated to increase frequency with predictions of increased global surface temperatures and extreme weather events. Although heat acclimation training (HAT) could prevent heat-related diseases, the mechanisms underlying HAT-promoting beneficial changes in organ function, immunity, and gut microbes remain unclear. Methods In the current study, we recruited 32 healthy young soldiers and randomly divided them into 4 teams to conduct HATs for 10 days: the equipment-assisted training team at high temperature (HE); the equipment-assisted training team under normal hot weather (NE); the high-intensity interval training team at high temperature (HIIT), and the control team without training. A standard heat tolerance test (HTT) was conducted before (HTT-1st) and after (HTT-2nd) the training to judge whether the participants met the heat acclimation (HA) criteria. Results We found that the participants in both HE and NE teams had significantly higher acclimation rates (HA/total population) than whom in the HIIT team. The effects of HAT on the participants of the HE team outperformed that of the NE team. In the HA group, the differences of physiological indicators and plasma organ damage biomarkers (ALT, ALP, creatinine, LDH, α-HBDH and cholinesterase) before and after HTT-2nd were significantly reduced to those during HTT-1st, but the differences of immune factors (IL-10, IL-6, CXCL2, CCL4, CCL5, and CCL11) elevated. The composition, metabolism, and pathogenicity of gut microbes changed significantly, with a decreased proportion of potentially pathogenic bacteria (Escherichia-Shigella and Lactococcus) and increased probiotics (Dorea, Blautia, and Lactobacillus) in the HA group. Training for a longer time in a high temperature and humidity showed beneficial effects for intestinal probiotics. Conclusion These findings revealed that pathogenic gut bacteria decrease while probiotics increase following HA, with elevated immune factors and reduced organ damage during heat stress, thereby improving the body's heat adaption.
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Affiliation(s)
- Shanshou Liu
- Department of Immunology, Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Dongqing Wen
- Air Force Medical Center, Fourth Military Medical University, Beijing, China
| | - Chongyang Feng
- Department of Immunology, Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Chaoping Yu
- Department of Immunology, Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Zhao Gu
- Air Force Medical Center, Fourth Military Medical University, Beijing, China
| | - Liping Wang
- Air Force Medical Center, Fourth Military Medical University, Beijing, China
| | - Zhixiang Zhang
- Department of Immunology, Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Wenpeng Li
- Department of Immunology, Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Shuwen Wu
- Department of Immunology, Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Yitian Liu
- Department of Immunology, Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Chujun Duan
- Department of Immunology, Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Ran Zhuang
- Department of Immunology, Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Lihao Xue
- Air Force Medical Center, Fourth Military Medical University, Beijing, China
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Haq A, Ribbans WJ, Hohenauer E, Baross AW. The Comparative Effect of Different Timings of Whole Body Cryotherapy Treatment With Cold Water Immersion for Post-Exercise Recovery. Front Sports Act Living 2022; 4:940516. [PMID: 35873209 PMCID: PMC9299249 DOI: 10.3389/fspor.2022.940516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 06/16/2022] [Indexed: 11/30/2022] Open
Abstract
Despite several established benefits of Whole Body Cryotherapy (WBC) for post-exercise recovery, there is a scarcity of research which has identified the optimum WBC protocol for this purpose. This study investigated the influence of WBC treatment timing on physiological and functional responses following a downhill running bout. An additional purpose was to compare such responses with those following cold water immersion (CWI), since there is no clear consensus as to which cold modality is more effective for supporting athletic recovery. Thirty-three male participants (mean ± SD age 37.0 ± 13.3 years, height 1.76 ± 0.07 m, body mass 79.5 ± 13.7 kg) completed a 30 min downhill run (15% gradient) at 60% VO2 max and were then allocated into one of four recovery groups: WBC1 (n = 9) and WBC4 (n = 8) underwent cryotherapy (3 min, −120°C) 1 and 4 h post-run, respectively; CWI (n = 8) participants were immersed in cold water (10 min, 15°C) up to the waist 1 h post-run and control (CON, n = 8) participants passively recovered in a controlled environment (20°C). Maximal isometric leg muscle torque was assessed pre and 24 h post-run. Blood creatine kinase (CK), muscle soreness, femoral artery blood flow, plasma IL-6 and sleep were also assessed pre and post-treatment. There were significant decreases in muscle torque for WBC4 (10.9%, p = 0.04) and CON (11.3% p = 0.00) and no significant decreases for WBC1 (5.6%, p = 0.06) and CWI (5.1%, p = 0.15). There were no significant differences between groups in muscle soreness, CK, IL-6 or sleep. Femoral artery blood flow significantly decreased in CWI (p = 0.02), but did not differ in other groups. WBC treatments within an hour may be preferable for muscle strength recovery compared to delayed treatments; however WBC appears to be no more effective than CWI. Neither cold intervention had an impact on inflammation or sleep.
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Affiliation(s)
- Adnan Haq
- Sports Studies, Moulton College, Moulton, United Kingdom
- Sport and Exercise Science, University of Northampton, Northampton, United Kingdom
- School of Health, Sport and Professional Practice, University of South Wales Sport Park, Pontypridd, United Kingdom
- *Correspondence: Adnan Haq
| | - William J. Ribbans
- Sport and Exercise Science, University of Northampton, Northampton, United Kingdom
- The County Clinic, Northampton, United Kingdom
| | - Erich Hohenauer
- Department of Business Economics, Health and Social Care, University of Applied Sciences and Arts of Southern Switzerland, Landquart, Switzerland
| | - Anthony W. Baross
- Sport and Exercise Science, University of Northampton, Northampton, United Kingdom
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The Effects of Age and Body Fat Content on Post-Downhill Run Recovery Following Whole Body Cryotherapy. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18062906. [PMID: 33809147 PMCID: PMC8001899 DOI: 10.3390/ijerph18062906] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 02/08/2021] [Accepted: 02/14/2021] [Indexed: 01/04/2023]
Abstract
This study explored the effects of age and body fat content on responses to whole body cryotherapy (WBC) following a downhill running bout. Forty-one male participants (mean ± SD age 42.0 ± 13.7 years, body mass 75.2 ± 10.8 kg) were allocated into WBC (n = 26) and control (CON, n = 15) groups. WBC participants were divided into old (OLD, ≥45 years, n = 10) and young (YNG, <40 years, n = 13), as well as high fat (HFAT, ≥20%, n = 10) and low fat (LFAT ≤ 15%, n = 8) groups. Participants completed a 30 min downhill run (15% gradient) at 60% VO2 max. The WBC group underwent cryotherapy (3 min, −120 °C) 1 h post-run and CON participants passively recovered in a controlled environment (20 °C). Maximal isometric leg muscle torque was assessed pre and 24 h post-run. Blood creatine kinase (CK) and muscle soreness were assessed pre, post, one hour and 24 h post-run. Muscle torque significantly decreased in both groups post-downhill run (WBC: 220.6 ± 61.4 Nm vs. 208.3 ± 67.6 Nm, p = 0.02; CON: 239.7 ± 51.1 Nm vs. 212.1 ± 46.3 Nm, p = 0.00). The mean decrease in WBC was significantly less than in CON (p = 0.04). Soreness and CK increased 24 h post for WBC and CON (p < 0.01) with no difference between groups. Muscle torque significantly decreased in OLD participants (p = 0.04) but not in YNG (p = 0.55). There were no differences between HFAT and LFAT (all p values > 0.05). WBC may attenuate muscle damage and benefit muscle strength recovery following eccentrically biased exercises, particularly for young males.
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The effect of Omega-3 polyunsaturated fatty acid supplementation on exercise-induced muscle damage. J Int Soc Sports Nutr 2021; 18:9. [PMID: 33441158 PMCID: PMC7807509 DOI: 10.1186/s12970-020-00405-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 12/26/2020] [Indexed: 12/18/2022] Open
Abstract
Background Exercise-induced muscle damage (EIMD) results in transient muscle inflammation, strength loss, muscle soreness and may cause subsequent exercise avoidance. Omega-3 (n-3) supplementation may minimise EIMD via its anti-inflammatory properties, however, its efficacy remains unclear. Methods Healthy males (n = 14, 25.07 ± 4.05 years) were randomised to 3 g/day n-3 supplementation (N-3, n = 7) or placebo (PLA, n = 7). Following 4 weeks supplementation, a downhill running protocol (60 min, 65% V̇O2max, − 10% gradient) was performed. Creatine kinase (CK), interleukin (IL)-6 and tumour necrosis factor (TNF)-α, perceived muscle soreness, maximal voluntary isometric contraction (MVIC) and peak power were quantified pre, post, and 24, 48 and 72 h post-EIMD. Results Muscle soreness was significantly lower in N-3 vs PLA group at 24 h post-EIMD (p = 0.034). IL-6 was increased in PLA (p = 0.009) but not in N-3 (p = 0.434) following EIMD, however, no significant differences were noted between groups. Peak power was significantly suppressed in PLA relative to pre-EIMD but not in N-3 group at 24 h post-EIMD. However, no significant difference in peak power output was observed between groups. MVIC, CK and TNF-α were altered by EIMD but did not differ between groups. Conclusion N-3 supplementation for 4 weeks may successfully attenuate minor aspects of EIMD. Whilst not improving performance, these findings may have relevance to soreness-associated exercise avoidance. Supplementary Information The online version contains supplementary material available at 10.1186/s12970-020-00405-1.
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Bontemps B, Vercruyssen F, Gruet M, Louis J. Downhill Running: What Are The Effects and How Can We Adapt? A Narrative Review. Sports Med 2020; 50:2083-2110. [PMID: 33037592 PMCID: PMC7674385 DOI: 10.1007/s40279-020-01355-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Downhill running (DR) is a whole-body exercise model that is used to investigate the physiological consequences of eccentric muscle actions and/or exercise-induced muscle damage (EIMD). In a sporting context, DR sections can be part of running disciplines (off-road and road running) and can accentuate EIMD, leading to a reduction in performance. The purpose of this narrative review is to: (1) better inform on the acute and delayed physiological effects of DR; (2) identify and discuss, using a comprehensive approach, the DR characteristics that affect the physiological responses to DR and their potential interactions; (3) provide the current state of evidence on preventive and in-situ strategies to better adapt to DR. Key findings of this review show that DR may have an impact on exercise performance by altering muscle structure and function due to EIMD. In the majority of studies, EIMD are assessed through isometric maximal voluntary contraction, blood creatine kinase and delayed onset muscle soreness, with DR characteristics (slope, exercise duration, and running speed) acting as the main influencing factors. In previous studies, the median (25th percentile, Q1; 75th percentile, Q3) slope, exercise duration, and running speed were - 12% (- 15%; - 10%), 40 min (30 min; 45 min) and 11.3 km h-1 (9.8 km h-1; 12.9 km h-1), respectively. Regardless of DR characteristics, people the least accustomed to DR generally experienced the most EIMD. There is growing evidence to suggest that preventive strategies that consist of prior exposure to DR are the most effective to better tolerate DR. The effectiveness of in-situ strategies such as lower limb compression garments and specific footwear remains to be confirmed. Our review finally highlights important discrepancies between studies in the assessment of EIMD, DR protocols and populations, which prevent drawing firm conclusions on factors that most influence the response to DR, and adaptive strategies to DR.
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Affiliation(s)
- Bastien Bontemps
- Université de Toulon, Laboratoire IAPS, Toulon, France
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, L3 3AF, UK
| | | | - Mathieu Gruet
- Université de Toulon, Laboratoire IAPS, Toulon, France
| | - Julien Louis
- Research Institute for Sport and Exercise Sciences, Liverpool John Moores University, Liverpool, L3 3AF, UK.
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Westwood CS, Fallowfield JL, Delves SK, Nunns M, Ogden HB, Layden JD. Individual risk factors associated with exertional heat illness: A systematic review. Exp Physiol 2020; 106:191-199. [PMID: 32249985 DOI: 10.1113/ep088458] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 03/30/2020] [Indexed: 12/17/2022]
Abstract
NEW FINDINGS What is the topic of this review? Exertional heat illness (EHI) remains a persistent problem for athletes and individuals. This threat remains despite numerous athletic position statements and occupational guidance policies. This review explores primary evidence that demonstrates a direct association between 'known' risk factors and EHI. What advances does it highlight? Primary evidence to support 'known' risk factors associated with EHI is not comprehensive. Furthermore, it is not evident that single individual factors predispose individuals to greater risk. In fact, the evidence indicates that EHI can manifest in non-hostile compensable environments when a combination of risk factors is prevalent. ABSTRACT Despite the widespread knowledge of exertional heat illness (EHI) and clear guidance for its prevention, the incidence of EHI remains high. We carried out a systematic review of available literature evaluating the scientific evidence underpinning the risk factors associated with EHI. Medline, PsycINFO, SportDiscus and Embase were searched from inception to January 2019 with no date limitation, with supplementary searches also being performed. Search terms included permutations of risk and heat illness, with only studies in English included. Study selection, data extraction and quality assessment, using the QUALSYST tool, were performed by two independent reviewers. Of 8898 articles identified by the searches, 42 were included in the systematic review as primary evidence demonstrating a link between a risk factor and EHI. The quality scores ranged from 57.50 to 100%, and studies were generally considered to be of strong quality. The majority of risks attributable to EHI were categorized as those associated with lifestyle factors. The findings from the systematic review suggest complex manifestation of EHI through multiple risk factors rather than any one factor in isolation. Further research is needed to explore the accumulation of risk factors to help in development of effective preventative measures.
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Affiliation(s)
- Caroline S Westwood
- School of Sport, Health and Wellbeing, Plymouth Marjon University, Plymouth, UK
| | | | | | - Michael Nunns
- Exeter Health Services and Delivery Research Evidence Synthesis Centre, Institute of Health Research, University of Exeter Medical School, University of Exeter, Exeter, UK
| | - Henry B Ogden
- School of Sport, Health and Wellbeing, Plymouth Marjon University, Plymouth, UK
| | - Joseph D Layden
- School of Sport, Health and Wellbeing, Plymouth Marjon University, Plymouth, UK
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Ogden HB, Child RB, Fallowfield JL, Delves SK, Westwood CS, Layden JD. The Gastrointestinal Exertional Heat Stroke Paradigm: Pathophysiology, Assessment, Severity, Aetiology and Nutritional Countermeasures. Nutrients 2020; 12:E537. [PMID: 32093001 PMCID: PMC7071449 DOI: 10.3390/nu12020537] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Revised: 02/14/2020] [Accepted: 02/15/2020] [Indexed: 12/12/2022] Open
Abstract
Exertional heat stroke (EHS) is a life-threatening medical condition involving thermoregulatory failure and is the most severe condition along a continuum of heat-related illnesses. Current EHS policy guidance principally advocates a thermoregulatory management approach, despite growing recognition that gastrointestinal (GI) microbial translocation contributes to disease pathophysiology. Contemporary research has focused to understand the relevance of GI barrier integrity and strategies to maintain it during periods of exertional-heat stress. GI barrier integrity can be assessed non-invasively using a variety of in vivo techniques, including active inert mixed-weight molecular probe recovery tests and passive biomarkers indicative of GI structural integrity loss or microbial translocation. Strenuous exercise is strongly characterised to disrupt GI barrier integrity, and aspects of this response correlate with the corresponding magnitude of thermal strain. The aetiology of GI barrier integrity loss following exertional-heat stress is poorly understood, though may directly relate to localised hyperthermia, splanchnic hypoperfusion-mediated ischemic injury, and neuroendocrine-immune alterations. Nutritional countermeasures to maintain GI barrier integrity following exertional-heat stress provide a promising approach to mitigate EHS. The focus of this review is to evaluate: (1) the GI paradigm of exertional heat stroke; (2) techniques to assess GI barrier integrity; (3) typical GI barrier integrity responses to exertional-heat stress; (4) the aetiology of GI barrier integrity loss following exertional-heat stress; and (5) nutritional countermeasures to maintain GI barrier integrity in response to exertional-heat stress.
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Affiliation(s)
- Henry B. Ogden
- Faculty of Sport, Health and Wellbeing, Plymouth MARJON University, Derriford Rd, Plymouth PL6 8BH, UK; (C.S.W.); (J.D.L.)
| | - Robert B. Child
- School of Chemical Engineering, University of Birmingham, Birmingham B15 2QU, UK;
| | | | - Simon K. Delves
- Institute of Naval Medicine, Alverstoke PO12 2DW, UK; (J.L.F.); (S.K.D.)
| | - Caroline S. Westwood
- Faculty of Sport, Health and Wellbeing, Plymouth MARJON University, Derriford Rd, Plymouth PL6 8BH, UK; (C.S.W.); (J.D.L.)
| | - Joseph D. Layden
- Faculty of Sport, Health and Wellbeing, Plymouth MARJON University, Derriford Rd, Plymouth PL6 8BH, UK; (C.S.W.); (J.D.L.)
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Casadio JR, Kilding AE, Cotter JD, Laursen PB. From Lab to Real World: Heat Acclimation Considerations for Elite Athletes. Sports Med 2018; 47:1467-1476. [PMID: 28035584 DOI: 10.1007/s40279-016-0668-9] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
As major sporting events are often held in hot environments, increased interest in ways of optimally heat acclimating athletes to maximise performance has emerged. Heat acclimation involves repeated exercise sessions in hot conditions that induce physiological and thermoregulatory adaptations that attenuate heat-induced performance impairments. Current evidence-based guidelines for heat acclimation are clear, but the application of these recommendations is not always aligned with the time commitments and training priorities of elite athletes. Alternative forms of heat acclimation investigated include hot water immersion and sauna bathing, yet uncertainty remains around the efficacy of these methods for reducing heat-induced performance impairments, as well as how this form of heat stress may add to an athlete's overall training load. An understanding of how to optimally prescribe and periodise heat acclimation based on the performance determinants of a given event is limited, as is knowledge of how heat acclimation may affect the quality of concurrent training sessions. Finally, differences in individual athlete responses to heat acclimation need to be considered. This article addresses alternative methods of heat acclimation and heat exposure, explores gaps in literature around understanding the real world application of heat acclimation for athletes, and highlights specific athlete considerations for practitioners.
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Affiliation(s)
- Julia R Casadio
- Sports Performance Research Institute New Zealand (SPRINZ), School of Sport and Recreation, Auckland University of Technology, Auckland, New Zealand.
- High Performance Sport New Zealand, PO Box 302 563, North Harbour, Auckland, 0751, New Zealand.
| | - Andrew E Kilding
- Sports Performance Research Institute New Zealand (SPRINZ), School of Sport and Recreation, Auckland University of Technology, Auckland, New Zealand
| | - James D Cotter
- School of Physical Education, Sport and Exercise Sciences, University of Otago, Dunedin, New Zealand
| | - Paul B Laursen
- Sports Performance Research Institute New Zealand (SPRINZ), School of Sport and Recreation, Auckland University of Technology, Auckland, New Zealand
- High Performance Sport New Zealand, PO Box 302 563, North Harbour, Auckland, 0751, New Zealand
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Tuttle JA, Chrismas BCR, Gibson OR, Barrington JH, Hughes DC, Castle PC, Metcalfe AJ, Midgley AW, Pearce O, Kabir C, Rayanmarakar F, Al-Ali S, Lewis MP, Taylor L. The Hsp72 and Hsp90α mRNA Responses to Hot Downhill Running Are Reduced Following a Prior Bout of Hot Downhill Running, and Occur Concurrently within Leukocytes and the Vastus Lateralis. Front Physiol 2017; 8:473. [PMID: 28747888 PMCID: PMC5506191 DOI: 10.3389/fphys.2017.00473] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 06/21/2017] [Indexed: 12/14/2022] Open
Abstract
The leukocyte heat shock response (HSR) is used to determine individual's thermotolerance. The HSR and thermotolerance are enhanced following interventions such as preconditioning and/or acclimation/acclimatization. However, it is unclear whether the leukocyte HSR is an appropriate surrogate for the HSR in other tissues implicated within the pathophysiology of exertional heat illnesses (e.g., skeletal muscle), and whether an acute preconditioning strategy (e.g., downhill running) can improve subsequent thermotolerance. Physically active, non-heat acclimated participants were split into two groups to investigate the benefits of hot downhill running as preconditioning strategy. A hot preconditioning group (HPC; n = 6) completed two trials (HPC1HOTDOWN and HPC2HOTDOWN) of 30 min running at lactate threshold (LT) on -10% gradient in 30°C and 50% relative humidity (RH) separated by 7 d. A temperate preconditioning group (TPC; n = 5) completed 30 min running at LT on a -1% gradient in 20°C and 50% (TPC1TEMPFLAT) and 7 d later completed 30 min running at LT on -10% gradient in 30°C and 50% RH (TPC2HOTDOWN). Venous blood samples and muscle biopsies (vastus lateralis; VL) were obtained before, immediately after, 3, 24, and 48 h after each trial. Leukocyte and VL Hsp72, Hsp90α, and Grp78 mRNA relative expression was determined via RT-QPCR. Attenuated leukocyte and VL Hsp72 (2.8 to 1.8 fold and 5.9 to 2.4 fold; p < 0.05) and Hsp90α mRNA (2.9 to 2.4 fold and 5.2 to 2.4 fold; p < 0.05) responses accompanied reductions (p < 0.05) in physiological strain [exercising rectal temperature (-0.3°C) and perceived muscle soreness (~ -14%)] during HPC2HOTDOWN compared to HPC1HOTDOWN (i.e., a preconditioning effect). Both VL and leukocyte Hsp72 and Hsp90α mRNA increased (p < 0.05) simultaneously following downhill runs and demonstrated a strong relationship (p < 0.01) of similar magnitudes with one another. Hot downhill running is an effective preconditioning strategy which ameliorates physiological strain, soreness and Hsp72 and Hsp90α mRNA responses to a subsequent bout. Leukocyte and VL analyses are appropriate tissues to infer the extent to which the HSR has been augmented.
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Affiliation(s)
- James A Tuttle
- Muscle Cellular and Molecular Physiology Research Group, Department of Sport Science and Physical Activity, Institute of Sport and Physical Activity Research, University of BedfordshireBedford, United Kingdom
| | - Bryna C R Chrismas
- Sport Science Program, College of Arts and Sciences, Qatar UniversityDoha, Qatar
| | - Oliver R Gibson
- Centre for Human Performance, Exercise and Rehabilitation, Division of Sport, Health and Exercise Sciences, Department of Life Sciences, Brunel University LondonLondon, United Kingdom
| | - James H Barrington
- Muscle Cellular and Molecular Physiology Research Group, Department of Sport Science and Physical Activity, Institute of Sport and Physical Activity Research, University of BedfordshireBedford, United Kingdom
| | - David C Hughes
- Department of Neurobiology, Physiology and Behavior, University of California, DavisDavis, CA, United States
| | - Paul C Castle
- Muscle Cellular and Molecular Physiology Research Group, Department of Sport Science and Physical Activity, Institute of Sport and Physical Activity Research, University of BedfordshireBedford, United Kingdom
| | - Alan J Metcalfe
- Muscle Cellular and Molecular Physiology Research Group, Department of Sport Science and Physical Activity, Institute of Sport and Physical Activity Research, University of BedfordshireBedford, United Kingdom.,School of Exercise and Health Sciences, Edith Cowan UniversityPerth, WA, Australia
| | - Adrian W Midgley
- Department of Sport and Physical Activity, Edgehill UniversityOrmskirk, United Kingdom
| | - Oliver Pearce
- Milton Keynes University HospitalMilton Keynes, United Kingdom
| | - Chindu Kabir
- Milton Keynes University HospitalMilton Keynes, United Kingdom
| | | | - Sami Al-Ali
- Milton Keynes University HospitalMilton Keynes, United Kingdom
| | - Mark P Lewis
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough UniversityLoughborough, United Kingdom.,School of Sport, Exercise and Health Sciences, Loughborough UniversityLoughborough, United Kingdom
| | - Lee Taylor
- School of Sport, Exercise and Health Sciences, Loughborough UniversityLoughborough, United Kingdom.,ASPETAR, Qatar Orthopedic and Sports Medicine HospitalDoha, Qatar
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Vargas N, Marino F. Heat stress, gastrointestinal permeability and interleukin-6 signaling - Implications for exercise performance and fatigue. Temperature (Austin) 2016; 3:240-251. [PMID: 27857954 PMCID: PMC4964994 DOI: 10.1080/23328940.2016.1179380] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 04/12/2016] [Accepted: 04/13/2016] [Indexed: 02/07/2023] Open
Abstract
Exercise in heat stress exacerbates performance decrements compared to normothermic environments. It has been documented that the performance decrements are associated with reduced efferent drive from the central nervous system (CNS), however, specific factors that contribute to the decrements are not completely understood. During exertional heat stress, blood flow is preferentially distributed away from the intestinal area to supply the muscles and brain with oxygen. Consequently, the gastrointestinal barrier becomes increasingly permeable, resulting in the release of lipopolysaccharides (LPS, endotoxin) into the circulation. LPS leakage stimulates an acute-phase inflammatory response, including the release of interleukin (IL)-6 in response to an increasingly endotoxic environment. If LPS translocation is too great, heat shock, neurological dysfunction, or death may ensue. IL-6 acts initially in a pro-inflammatory manner during endotoxemia, but can attenuate the response through signaling the hypothalamic pituitary adrenal (HPA)-axis. Likewise, IL-6 is believed to be a thermoregulatory sensor in the gut during the febrile response, hence highlighting its role in periphery – to – brain communication. Recently, IL-6 has been implicated in signaling the CNS and influencing perceptions of fatigue and performance during exercise. Therefore, due to the cascade of events that occur during exertional heat stress, it is possible that the release of LPS and exacerbated response of IL-6 contributes to CNS modulation during exertional heat stress. The purpose of this review is to evaluate previous literature and discuss the potential role for IL-6 during exertional heat stress to modulate performance in favor of whole body preservation.
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Affiliation(s)
- Nicole Vargas
- School of Exercise Science, Sport & Health, Charles Sturt University , Bathurst, NSW, Australia
| | - Frank Marino
- School of Exercise Science, Sport & Health, Charles Sturt University , Bathurst, NSW, Australia
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