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Watanabe K, Koch Esteves N, Gibson OR, Akiyama K, Watanabe S, González-Alonso J. Heat-related changes in the velocity and kinetic energy of flowing blood influence the human heart's output during hyperthermia. J Physiol 2024; 602:2227-2251. [PMID: 38690610 DOI: 10.1113/jp285760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Accepted: 04/03/2024] [Indexed: 05/02/2024] Open
Abstract
Passive whole-body hyperthermia increases limb blood flow and cardiac output (Q ̇ $\dot Q$ ), but the interplay between peripheral and central thermo-haemodynamic mechanisms remains unclear. Here we tested the hypothesis that local hyperthermia-induced alterations in peripheral blood flow and blood kinetic energy modulate flow to the heart andQ ̇ $\dot Q$ . Body temperatures, regional (leg, arm, head) and systemic haemodynamics, and left ventricular (LV) volumes and functions were assessed in eight healthy males during: (1) 3 h control (normothermic condition); (2) 3 h of single-leg heating; (3) 3 h of two-leg heating; and (4) 2.5 h of whole-body heating. Leg, forearm, and extracranial blood flow increased in close association with local rises in temperature while brain perfusion remained unchanged. Increases in blood velocity with small to no changes in the conduit artery diameter underpinned the augmented limb and extracranial perfusion. In all heating conditions,Q ̇ $\dot Q$ increased in association with proportional elevations in systemic vascular conductance, related to enhanced blood flow, blood velocity, vascular conductance and kinetic energy in the limbs and head (all R2 ≥ 0.803; P < 0.001), but not in the brain. LV systolic (end-systolic elastance and twist) and diastolic functional profiles (untwisting rate), pulmonary ventilation and systemic aerobic metabolism were only altered in whole-body heating. These findings substantiate the idea that local hyperthermia-induced selective alterations in peripheral blood flow modulate the magnitude of flow to the heart andQ ̇ $\dot Q$ through changes in blood velocity and kinetic energy. Localised heat-activated events in the peripheral circulation therefore affect the human heart's output. KEY POINTS: Local and whole-body hyperthermia increases limb and systemic perfusion, but the underlying peripheral and central heat-sensitive mechanisms are not fully established. Here we investigated the regional (leg, arm and head) and systemic haemodynamics (cardiac output:Q ̇ $\dot Q$ ) during passive single-leg, two-leg and whole-body hyperthermia to determine the contribution of peripheral and central thermosensitive factors in the control of human circulation. Single-leg, two-leg, and whole-body hyperthermia induced graded increases in leg blood flow andQ ̇ $\dot Q$ . Brain blood flow, however, remained unchanged in all conditions. Ventilation, extracranial blood flow and cardiac systolic and diastolic functions only increased during whole-body hyperthermia. The augmentedQ ̇ $\dot Q$ with hyperthermia was tightly related to increased limb and head blood velocity, flow and kinetic energy. The findings indicate that local thermosensitive mechanisms modulate regional blood velocity, flow and kinetic energy, thereby controlling the magnitude of flow to the heart and thus the coupling of peripheral and central circulation during hyperthermia.
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Affiliation(s)
- Kazuhito Watanabe
- Division of Sport, Health and Exercise Sciences, Department of Life Sciences, Brunel University London, Uxbridge, UK
- Faculty of Education and Human Studies, Akita University, Akita, Japan
| | - Nuno Koch Esteves
- Division of Sport, Health and Exercise Sciences, Department of Life Sciences, Brunel University London, Uxbridge, UK
- Research Centre, University College of Osteopathy, London, UK
| | - Oliver R Gibson
- Division of Sport, Health and Exercise Sciences, Department of Life Sciences, Brunel University London, Uxbridge, UK
- Centre for Physical Activity in Health and Disease, Brunel University London, Uxbridge, UK
| | - Koichi Akiyama
- Department of Anesthesiology, Kindai University Hospital, Osaka, Japan
| | - Sumie Watanabe
- Division of Sport, Health and Exercise Sciences, Department of Life Sciences, Brunel University London, Uxbridge, UK
- Faculty of Education and Human Studies, Akita University, Akita, Japan
| | - José González-Alonso
- Division of Sport, Health and Exercise Sciences, Department of Life Sciences, Brunel University London, Uxbridge, UK
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Willmott AGB, Diment AG, Chung HC, James CA, Maxwell NS, Roberts JD, Gibson OR. Cross-adaptation from heat stress to hypoxia: A systematic review and exploratory meta-analysis. J Therm Biol 2024; 120:103793. [PMID: 38471285 DOI: 10.1016/j.jtherbio.2024.103793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Revised: 01/03/2024] [Accepted: 01/12/2024] [Indexed: 03/14/2024]
Abstract
Cross-adaptation (CA) refers to the successful induction of physiological adaptation under one environmental stressor (e.g., heat), to enable subsequent benefit in another (e.g., hypoxia). This systematic review and exploratory meta-analysis investigated the effect of heat acclimation (HA) on physiological, perceptual and physical performance outcome measures during rest, and submaximal and maximal intensity exercise in hypoxia. Database searches in Scopus and MEDLINE were performed. Studies were included when they met the Population, Intervention, Comparison, and Outcome criteria, were of English-language, peer-reviewed, full-text original articles, using human participants. Risk of bias and study quality were assessed using the COnsensus based Standards for the selection of health status Measurement INstruments checklist. Nine studies were included, totalling 79 participants (100 % recreationally trained males). The most common method of HA included fixed-intensity exercise comprising 9 ± 3 sessions, 89 ± 24-min in duration and occurred within 39 ± 2 °C and 32 ± 13 % relative humidity. CA induced a moderate, beneficial effect on physiological measures at rest (oxygen saturation: g = 0.60) and during submaximal exercise (heart rate: g = -0.65, core temperature: g = -0.68 and skin temperature: g = -0.72). A small effect was found for ventilation (g = 0.24) and performance measures (peak power: g = 0.32 and time trial time: g = -0.43) during maximal intensity exercise. No effect was observed for perceptual outcome measures. CA may be appropriate for individuals, such as occupational or military workers, whose access to altitude exposure prior to undertaking submaximal activity in hypoxic conditions is restricted. Methodological variances exist within the current literature, and females and well-trained individuals have yet to be investigated. Future research should focus on these cohorts and explore the mechanistic underpinnings of CA.
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Affiliation(s)
- Ashley G B Willmott
- The Cambridge Centre for Sport and Exercise Sciences (CCSES), Anglia Ruskin University, East Road, Cambridge, United Kingdom; Environmental Extremes Laboratory, University of Brighton, Eastbourne, East Sussex, United Kingdom; Para-Monte Altitude Awareness Charity, Eastbourne, East Sussex, United Kingdom.
| | - Alicia G Diment
- The Cambridge Centre for Sport and Exercise Sciences (CCSES), Anglia Ruskin University, East Road, Cambridge, United Kingdom; Pulmonary Function Laboratory, Norfolk and Norwich University Hospital, Colney Lane, Norwich, Norfolk, United Kingdom.
| | - Henry C Chung
- School of Sport, Rehabilitation and Exercise Sciences (SRES), University of Essex, Colchester, Essex, United Kingdom.
| | - Carl A James
- Hong Kong Sports Institute, Sha Tin, Hong Kong, China; Department of Sport, Physical Education and Health, Hong Kong Baptist University, Kowloon Tong, Hong Kong, China.
| | - Neil S Maxwell
- Environmental Extremes Laboratory, University of Brighton, Eastbourne, East Sussex, United Kingdom; Para-Monte Altitude Awareness Charity, Eastbourne, East Sussex, United Kingdom.
| | - Justin D Roberts
- The Cambridge Centre for Sport and Exercise Sciences (CCSES), Anglia Ruskin University, East Road, Cambridge, United Kingdom.
| | - Oliver R Gibson
- Centre for Physical Activity in Health and Disease (CPAHD), Division of Sport, Health and Exercise Sciences, Brunel University London, Uxbridge, United Kingdom.
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Willmott AGB, James CA, Hayes M, Maxwell NS, Roberts J, Gibson OR. The reliability of a portable steam sauna pod for the whole-body passive heating of humans. J Therm Biol 2023; 118:103743. [PMID: 37979477 DOI: 10.1016/j.jtherbio.2023.103743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 10/16/2023] [Accepted: 10/17/2023] [Indexed: 11/20/2023]
Abstract
INTRODUCTION Passive heating is receiving increasing attention within human performance and health contexts. A low-cost, portable steam sauna pod may offer an additional tool for those seeking to manipulate physiological (cardiovascular, thermoregulatory and sudomotor) and perceptual responses for improving sporting or health profiles. This study aimed to 1) report the different levels of heat stress and determine the pods' inter-unit reliability, and 2) quantify the reliability of physiological and perceptual responses to passive heating. METHOD In part 1, five pods were assessed for temperature and relative humidity (RH) every 5 min across 70 min of heating for each of the 9 settings. In part 2, twelve males (age: 24 ± 4 years) completed two 60 min trials of passive heating (3 × 20 min at 44 °C/99% RH, separated by 1 week). Heart rate (HR), rectal (Trectal) and tympanic temperature (Ttympanic) were recorded every 5 min, thermal comfort (Tcomfort) and sensation (Tsensation) every 10 min, mean arterial pressure (MAP) at each break period and sweat rate (SR) after exiting the pod. RESULTS In part 1, setting 9 provided the highest temperature (44.3 ± 0.2 °C) and longest time RH remained stable at 99% (51±7 min). Inter-unit reliability data demonstrated agreement between pods for settings 5-9 (intra-class correlation [ICC] >0.9), but not for settings 1-4 (ICC <0.9). In part 2, between-visits, high correlations, and low typical error of measurement (TEM) and coefficient of variation (CV) were found for Trectal, HR, MAP, SR, and Tcomfort, but not for Ttympanic or Tsensation. A peak Trectal of 38.09 ± 0.30 °C, HR of 124 ± 15 b min-1 and a sweat loss of 0.73 ± 0.33 L were reported. No between-visit differences (p > 0.05) were observed for Trectal, Ttympanic, Tsensation or Tcomfort, however HR (+3 b.min-1) and MAP (+4 mmHg) were greater in visit 1 vs. 2 (p < 0.05). CONCLUSION Portable steam sauna pods generate reliable heat stress between-units. The highest setting (44 °C/99% RH) also provides reliable but modest adjustments in physiological and perceptual responses.
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Affiliation(s)
- A G B Willmott
- Cambridge Centre for Sport and Exercise Sciences (CCSES), Anglia Ruskin University, Cambridge, UK; Environmental Extremes Laboratory, University of Brighton, Eastbourne, UK.
| | - C A James
- Hong Kong Sports Institute (HKSI), Hong Kong; Department of Sport, Physical Education and Health, Hong Kong Baptist University. Kowloon Tong, Hong Kong
| | - M Hayes
- Environmental Extremes Laboratory, University of Brighton, Eastbourne, UK
| | - N S Maxwell
- Environmental Extremes Laboratory, University of Brighton, Eastbourne, UK
| | - J Roberts
- Cambridge Centre for Sport and Exercise Sciences (CCSES), Anglia Ruskin University, Cambridge, UK
| | - O R Gibson
- Centre for Physical Activity in Health and Disease (CHPAD), Division of Sport, Health and Exercise Sciences, Brunel University London, Uxbridge, UK
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Gibson OR, Astin R, Puthucheary Z, Yadav S, Preston S, Gavins FNE, González-Alonso J. Skeletal muscle angiogenic, regulatory, and heat shock protein responses to prolonged passive hyperthermia of the human lower limb. Am J Physiol Regul Integr Comp Physiol 2023; 324:R1-R14. [PMID: 36409025 DOI: 10.1152/ajpregu.00320.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Passive hyperthermia induces a range of physiological responses including augmenting skeletal muscle mRNA expression. This experiment aimed to examine gene and protein responses to prolonged passive leg hyperthermia. Seven young participants underwent 3 h of resting unilateral leg heating (HEAT) followed by a further 3 h of rest, with the contralateral leg serving as an unheated control (CONT). Muscle biopsies were taken at baseline (0 h), and at 1.5, 3, 4, and 6 h in HEAT and 0 and 6 h in CONT to assess changes in selected mRNA expression via qRT-PCR, and HSP72 and VEGFα concentration via ELISA. Muscle temperature (Tm) increased in HEAT plateauing from 1.5 to 3 h (+3.5 ± 1.5°C from 34.2 ± 1.2°C baseline value; P < 0.001), returning to baseline at 6 h. No change occurred in CONT. Endothelial nitric oxide synthase (eNOS), Forkhead box O1 (FOXO-1), Hsp72, and VEGFα mRNA increased in HEAT (P < 0.05); however, post hoc analysis identified that only Hsp72 mRNA statistically increased (at 4 h vs. baseline). When peak change during HEAT was calculated angiopoietin 2 (ANGPT-2) decreased (-0.4 ± 0.2-fold), and C-C motif chemokine ligand 2 (CCL2) (+2.9 ± 1.6-fold), FOXO-1 (+6.2 ± 4.4-fold), Hsp27 (+2.9 ± 1.7-fold), Hsp72 (+8.5 ± 3.5-fold), Hsp90α (+4.6 ± 3.7-fold), and VEGFα (+5.9 ± 3.1-fold) increased from baseline (all P < 0.05). At 6 h Tm were not different between limbs (P = 0.582; CONT = 32.5 ± 1.6°C, HEAT = 34.3 ± 1.2°C), and only ANGPT-2 (P = 0.031; -1.3 ± 1.4-fold) and VEGFα (P = 0.030; 1.1 ± 1.2-fold) differed between HEAT and CONT. No change in VEGFα or HSP72 protein concentration were observed over time; however, peak change in VEGFα did increase (P < 0.05) in HEAT (+140 ± 184 pg·mL-1) versus CONT (+7 ± 86 pg·mL-1). Passive hyperthermia transiently augmented ANGPT-2, CCL2, eNOS, FOXO-1, Hsp27, Hsp72, Hsp90α and VEGFα mRNA, and VEGFα protein.
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Affiliation(s)
- Oliver R Gibson
- Centre for Human Performance, Exercise and Rehabilitation, Brunel University London, Uxbridge, United Kingdom.,Centre for Physical Activity in Health and Disease, Brunel University London, Uxbridge, United Kingdom.,Division of Sport, Health and Exercise Sciences, Brunel University London, Uxbridge, United Kingdom
| | - Rónan Astin
- Department of Medicine, Centre for Human Health and Performance, University College London, London, United Kingdom
| | - Zudin Puthucheary
- Adult Critical Care Unit, Barts and The London School of Medicine and Dentistry, William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - Shreya Yadav
- Centre for Inflammation Research and Translational Medicine, Brunel University London, Uxbridge, United Kingdom.,Division of Biosciences, Brunel University London, Uxbridge, United Kingdom
| | - Sophie Preston
- Centre for Inflammation Research and Translational Medicine, Brunel University London, Uxbridge, United Kingdom.,Division of Biosciences, Brunel University London, Uxbridge, United Kingdom
| | - Felicity N E Gavins
- Centre for Inflammation Research and Translational Medicine, Brunel University London, Uxbridge, United Kingdom.,Division of Biosciences, Brunel University London, Uxbridge, United Kingdom
| | - José González-Alonso
- Centre for Human Performance, Exercise and Rehabilitation, Brunel University London, Uxbridge, United Kingdom.,Division of Sport, Health and Exercise Sciences, Brunel University London, Uxbridge, United Kingdom
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James CA, Willmott AG, Dhawan A, Stewart C, Gibson OR. Increased air temperature decreases high-speed, but not total distance, in international field hockey. Temperature (Austin) 2021; 9:357-372. [PMCID: PMC9629124 DOI: 10.1080/23328940.2021.1997535] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
This study investigated the effect of heat stress on locomotor activity within international field hockey at team, positional and playing-quarter levels. Analysis was conducted on 71 matches played by the Malaysia national men’s team against 24 opponents. Fixtures were assigned to match conditions, based on air temperature [COOL (14 ± 3°C), WARM (24 ± 1°C), HOT (27 ± 1°C), or VHOT (32 ± 2°C), p < 0.001]. Relationships between locomotor metrics and air temperature (AIR), absolute and relative humidity, and wet bulb globe temperature (WBGT) were investigated further using correlation and regression analyses. Increased AIR and WBGT revealed similar correlations (p < 0.01) with intensity metrics; high-speed running (AIR r = −0.51, WBGT r = −0.45), average speed (AIR r = −0.48, WBGT r = −0.46), decelerations (AIR r = −0.41, WBGT r = −0.41), sprinting efforts (AIR r = −0.40, WBGT r = −0.36), and sprinting distance (AIR r = −0.37, WBGT r = −0.29). In comparison to COOL, HOT, and VHOT matches demonstrated reduced high-speed running intensity (−14–17%; p < 0.001), average speed (−5-6%; p < 0.001), sprinting efforts (−17%; p = 0.010) and decelerations per min (−12%; p = 0.008). Interactions were found between match conditions and playing quarter for average speed (+4-7%; p = 0.002) and sprinting distance (+16-36%; p < 0.001), both of which were higher in the fourth quarter in COOL versus WARM, HOT and VHOT. There was an interaction for “low-speed” (p < 0.001), but not for “high-speed” running (p = 0.076) demonstrating the modulating effect of air temperature (particularly >25°C) on pacing within international hockey. These are the first data demonstrating the effect of air temperature on locomotor activity within international men’s hockey, notably that increased air temperature impairs high-intensity activities by 5–15%. Higher air temperatures compromise high-speed running distances between matches in hockey.
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Affiliation(s)
- Carl A James
- Institut Sukan Negara (National Sports Institute), National Sports Complex, Kuala Lumpur, Malaysia
- Environmental Extremes Laboratory, University of Brighton, Eastbourne, UK
| | - Ashley G.B. Willmott
- Environmental Extremes Laboratory, University of Brighton, Eastbourne, UK
- Cambridge Centre for Sport and Exercise Sciences, Anglia Ruskin University, Cambridge, UK
| | | | - Craig Stewart
- CS Performance, Clontarf Hockey Club, Dublin, Ireland
| | - Oliver R Gibson
- Centre for Human Performance, Exercise and Rehabilitation (CHPER), Division of Sport, Health and Exercise Sciences, Brunel University London, Uxbridge, UK
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Waldock KA, Gibson OR, Relf RL, Eichhorn G, Hayes M, Watt PW, Maxwell NS. Exercise heat acclimation and post-exercise hot water immersion improve resting and exercise responses to heat stress in the elderly. J Sci Med Sport 2021; 24:774-780. [DOI: 10.1016/j.jsams.2021.05.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 05/15/2021] [Accepted: 05/23/2021] [Indexed: 01/23/2023]
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Koch Esteves N, Gibson OR, Khir AW, González‐Alonso J. Regional thermal hyperemia in the human leg: Evidence of the importance of thermosensitive mechanisms in the control of the peripheral circulation. Physiol Rep 2021; 9:e14953. [PMID: 34350727 PMCID: PMC8339537 DOI: 10.14814/phy2.14953] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 06/13/2021] [Accepted: 06/15/2021] [Indexed: 02/04/2023] Open
Abstract
Hyperthermia is thought to increase limb blood flow through the activation of thermosensitive mechanisms within the limb vasculature, but the precise vascular locus in which hyperthermia modulates perfusion remains elusive. We tested the hypothesis that local temperature-sensitive mechanisms alter limb hemodynamics by regulating microvascular blood flow. Temperature and oxygenation profiles and leg hemodynamics of the common (CFA), superficial (SFA) and profunda (PFA) femoral arteries, and popliteal artery (POA) of the experimental and control legs were measured in healthy participants during: (1) 3 h of whole leg heating (WLH) followed by 3 h of recovery (n = 9); (2) 1 h of upper leg heating (ULH) followed by 30 min of cooling and 1 h ULH bout (n = 8); and (3) 1 h of lower leg heating (LLH) (n = 8). WLH increased experimental leg temperature by 4.2 ± 1.2ºC and blood flow in CFA, SFA, PFA, and POA by ≥3-fold, while the core temperature essentially remained stable. Upper and lower leg blood flow increased exponentially in response to leg temperature and then declined during recovery. ULH and LLH similarly increased the corresponding segmental leg temperature, blood flow, and tissue oxygenation without affecting these responses in the non-heated leg segment, or perfusion pressure and conduit artery diameter across all vessels. Findings demonstrate that whole leg hyperthermia induces profound and sustained elevations in upper and lower limb blood flow and that segmental hyperthermia matches the regional thermal hyperemia without causing thermal or hemodynamic alterations in the non-heated limb segment. These observations support the notion that heat-activated thermosensitive mechanisms in microcirculation regulate limb tissue perfusion during hyperthermia.
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Affiliation(s)
- Nuno Koch Esteves
- Centre for Human Performance, Exercise and RehabilitationCollege of Health, Medicine and Life SciencesBrunel University LondonUxbridgeUK
| | - Oliver R. Gibson
- Centre for Human Performance, Exercise and RehabilitationCollege of Health, Medicine and Life SciencesBrunel University LondonUxbridgeUK
- Division of Sport, Health and Exercise SciencesDepartment of Life SciencesCollege of Health, Medicine and Life SciencesBrunel University LondonUxbridgeUK
| | - Ashraf W. Khir
- Department of Mechanical and Aerospace EngineeringCollege of Engineering, Design and Physical SciencesBrunel University LondonUxbridgeUK
| | - José González‐Alonso
- Centre for Human Performance, Exercise and RehabilitationCollege of Health, Medicine and Life SciencesBrunel University LondonUxbridgeUK
- Division of Sport, Health and Exercise SciencesDepartment of Life SciencesCollege of Health, Medicine and Life SciencesBrunel University LondonUxbridgeUK
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Walter E, W Watt P, Gibson OR, Wilmott AGB, Mitchell D, Moreton R, Maxwell NS. Exercise hyperthermia induces greater changes in gastrointestinal permeability than equivalent passive hyperthermia. Physiol Rep 2021; 9:e14945. [PMID: 34409760 PMCID: PMC8374382 DOI: 10.14814/phy2.14945] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 06/05/2021] [Accepted: 06/06/2021] [Indexed: 01/09/2023] Open
Abstract
Hyperthermia and exertional heat illness increase gastrointestinal (GI) permeability, although whether the latter is only via hyperthermia is unclear. The aim of this pilot study was to determine whether different changes in GI permeability, characterized by an increased plasma lactulose:rhamnose concentration ratio ([L:R]), occurred in exercise hyperthermia in comparison to equivalent passive hyperthermia. Six healthy adult male participants (age 25 ± 5 years, mass 77.0 ± 6.7 kg, height 181 ± 6 cm, peak oxygen uptake [ V · O 2 peak ] 48 ± 8 ml.kg-1 .min-1 ) underwent exercise under hot conditions (Ex-Heat) and passive heating during hot water immersion (HWI). Heart rate (HR), rectal temperature (TCORE ), rating of perceived exertion (RPE), and whole-body sweat loss (WBSL) were recorded throughout the trials. The L:R ratio, peak HR, change in HR, and change in RPE were higher in Ex-Heat than HWI, despite no differences in trial duration, peak core temperature or WBSL. L:R was strongly correlated (p < 0.05) with HR peak (r = 0.626) and change in HR (r = 0.615) but no other variable. The greater L:R in Ex-Heat, despite equal TCORE responses to HWI, indicates that increased cardiovascular strain occurred during exercise, and exacerbates hyperthermia-induced GI permeability at the same absolute temperature.
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Affiliation(s)
- Edward Walter
- Department of Intensive CareRoyal Surrey County HospitalGuildfordUK
- Environmental Extremes Lab, Sport and Exercise Science and Medicine Research and Enterprise GroupUniversity of BrightonEastbourneEast SussexUK
| | - Peter W Watt
- Environmental Extremes Lab, Sport and Exercise Science and Medicine Research and Enterprise GroupUniversity of BrightonEastbourneEast SussexUK
| | - Oliver R. Gibson
- Centre for Human Performance, Exercise and Rehabilitation (CHPER)Division of Sport, Health and Exercise SciencesCollege of Health, Medicine, and Life SciencesBrunel University LondonUxbridgeUK
| | - Ashley G. B. Wilmott
- Environmental Extremes Lab, Sport and Exercise Science and Medicine Research and Enterprise GroupUniversity of BrightonEastbourneEast SussexUK
- Cambridge Centre for Sport and Exercise Sciences (CCSES)School of Psychology and Sport ScienceAnglia Ruskin UniversityCambridgeUK
| | - Dominic Mitchell
- Environmental Extremes Lab, Sport and Exercise Science and Medicine Research and Enterprise GroupUniversity of BrightonEastbourneEast SussexUK
| | - Robert Moreton
- Environmental Extremes Lab, Sport and Exercise Science and Medicine Research and Enterprise GroupUniversity of BrightonEastbourneEast SussexUK
| | - Neil S. Maxwell
- Environmental Extremes Lab, Sport and Exercise Science and Medicine Research and Enterprise GroupUniversity of BrightonEastbourneEast SussexUK
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James CA, Gibson OR, Dhawan A, Stewart CM, Willmott AGB. Volume and Intensity of Locomotor Activity in International Men's Field Hockey Matches Over a 2-Year Period. Front Sports Act Living 2021; 3:653364. [PMID: 34127962 PMCID: PMC8196230 DOI: 10.3389/fspor.2021.653364] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 03/31/2021] [Indexed: 11/27/2022] Open
Abstract
The locomotor demands of international men's field hockey matches were investigated across positions (DEF, MID, FWD) and playing quarters. Volume (i.e., total values) and intensity (i.e., relative to playing time) data were collected using 10-Hz GPS/100-Hz accelerometer units from the #11 world-ranked (WR) team, during 71 matches, against 24 opponents [WR 12 ± 11 (range, 1–60)]. Mean ± SD team total distance (TD) was 4,861 ± 871 m, with 25% (1,193 ± 329 m) “high-speed running” (>14.5 km h−1) and 8% (402 ± 144 m) “sprinting” (>19.0 km h−1). Reduced TD (range, −3 to 4%) and average speed (range, −3.4 to 4.7%) occurred through subsequent quarters, vs. Q1 (p < 0.05). A “large” negative relationship (r = −0.64) was found between playing duration and average speed. Positional differences (p < 0.05) were identified for all volume metrics including; playing duration (DEF, 45:50 ± 8:00 min; MID, 37:37 ± 7:12 min; FWD, 33:32 ± 6:22 min), TD (DEF, 5,223 ± 851 m; MID, 4,945 ± 827 m; FWD, 4,453 ± 741 m), sprinting distance (DEF, 315 ± 121 m; MID, 437 ± 144 m; FWD, 445 ± 129 m), and acceleration efforts (>2 m s−2; DEF, 48 ± 12; MID, 51 ± 11; FWD, 50 ± 14). Intensity variables similarly revealed positional differences (p < 0.05) but with a different pattern between positions; average speed (DEF, 115 ± 10 m min−1; MID, 132 ± 10 m min−1; FWD, 134 ± 15 m min−1), sprinting (DEF, 7 ± 3 m min−1; MID, 12 ± 4 m min−1; FWD, 14 ± 4 m min−1), and accelerations (DEF, 1.1 ± 0.3 n min−1; MID, 1.4 ± 0.2 n min−1; FWD, 1.5 ± 0.3 n min−1). Physical outputs reduced across playing quarters, despite unlimited substitutions, demonstrating the importance of optimizing physical preparation prior to international competition. Volume and intensity data highlight specific positional requirements, with forwards displaying shorter playing durations but greater high-intensity activities than defenders.
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Affiliation(s)
- Carl A James
- Sport Science Department, Institut Sukan Negara (National Sports Institute), Kuala Lumpur, Malaysia
| | - Oliver R Gibson
- Division of Sport, Health and Exercise Sciences, Center for Human Performance, Exercise and Rehabilitation (CHPER), Brunel University London, Uxbridge, United Kingdom
| | | | | | - Ashley G B Willmott
- Cambridge Center for Sport and Exercise Sciences, Anglia Ruskin University, Cambridge, United Kingdom
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Marshall H, Gibson OR, Romer LM, Illidi C, Hull JH, Kippelen P. Systemic but not local rehydration restores dehydration-induced changes in pulmonary function in healthy adults. J Appl Physiol (1985) 2021; 130:517-527. [PMID: 33300853 DOI: 10.1152/japplphysiol.00311.2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Water transport and local (airway) hydration are critical for the normal functioning of lungs and airways. Currently, there is uncertainty regarding the effects of systemic dehydration on pulmonary function. Our aims were 1) to clarify the impact of exercise- or fluid restriction-induced dehydration on pulmonary function in healthy adults; and 2) to establish whether systemic or local rehydration can reverse dehydration-induced alterations in pulmonary function. Ten healthy participants performed four experimental trials in a randomized order (2 h exercise in the heat twice and 28 h fluid restriction twice). Pulmonary function was assessed using spirometry and whole body plethysmography in the euhydrated, dehydrated, and rehydrated states. Oral fluid consumption was used for systemic rehydration and nebulized isotonic saline inhalation for local rehydration. Both exercise and fluid restriction induced mild dehydration (2.7 ± 0.7% and 2.5 ± 0.4% body mass loss, respectively; P < 0.001) and elevated plasma osmolality (P < 0.001). Dehydration across all four trials was accompanied by a reduction in forced vital capacity (152 ± 143 mL, P < 0.01) and concomitant increases in residual volume (216 ± 177 mL, P < 0.01) and functional residual capacity (130 ± 144 mL, P < 0.01), with no statistical differences between modes of dehydration. These changes were normalized by fluid consumption but not nebulization. Our results suggest that, in healthy adults: 1) mild systemic dehydration induced by exercise or fluid restriction leads to pulmonary function impairment, primarily localized to small airways; and 2) systemic, but not local, rehydration reverses these potentially deleterious alterations.NEW & NOTEWORTHY This study demonstrates that, in healthy adults, mild systemic dehydration induced by exercise in the heat or a prolonged period of fluid restriction leads to negative alterations in pulmonary function, primarily localized to small airways. Oral rehydration, but not nebulized isotonic saline, is able to restore pulmonary function in dehydrated individuals. Our findings highlight the importance of maintaining an adequate systemic fluid balance to preserve pulmonary function.
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Affiliation(s)
- Hannah Marshall
- Centre for Human Performance, Exercise, and Rehabilitation, Brunel University London, Uxbridge, United Kingdom
| | - Oliver R Gibson
- Centre for Human Performance, Exercise, and Rehabilitation, Brunel University London, Uxbridge, United Kingdom.,Division of Sport, Health, and Exercise Sciences, College of Health, Medicine, and Life Sciences, Brunel University London, Uxbridge, United Kingdom
| | - Lee M Romer
- Centre for Human Performance, Exercise, and Rehabilitation, Brunel University London, Uxbridge, United Kingdom.,Division of Sport, Health, and Exercise Sciences, College of Health, Medicine, and Life Sciences, Brunel University London, Uxbridge, United Kingdom
| | - Camilla Illidi
- Centre for Human Performance, Exercise, and Rehabilitation, Brunel University London, Uxbridge, United Kingdom
| | - James H Hull
- Centre for Human Performance, Exercise, and Rehabilitation, Brunel University London, Uxbridge, United Kingdom.,Department of Respiratory Medicine, Royal Brompton Hospital, London, United Kingdom
| | - Pascale Kippelen
- Centre for Human Performance, Exercise, and Rehabilitation, Brunel University London, Uxbridge, United Kingdom.,Division of Sport, Health, and Exercise Sciences, College of Health, Medicine, and Life Sciences, Brunel University London, Uxbridge, United Kingdom
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Barwood MJ, Gibson OR, Gillis DJ, Jeffries O, Morris NB, Pearce J, Ross ML, Stevens C, Rinaldi K, Kounalakis SN, Riera F, Mündel T, Waldron M, Best R. Menthol as an Ergogenic Aid for the Tokyo 2021 Olympic Games: An Expert-Led Consensus Statement Using the Modified Delphi Method. Sports Med 2020; 50:1709-1727. [PMID: 32623642 PMCID: PMC7497433 DOI: 10.1007/s40279-020-01313-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
INTRODUCTION Menthol topical application and mouth rinsing are ergogenic in hot environments, improving performance and perception, with differing effects on body temperature regulation. Consequently, athletes and federations are beginning to explore the possible benefits to elite sport performance for the Tokyo 2021 Olympics, which will take place in hot (~ 31 °C), humid (70% RH) conditions. There is no clear consensus on safe and effective menthol use for athletes, practitioners, or researchers. The present study addressed this shortfall by producing expert-led consensus recommendations. METHOD Fourteen contributors were recruited following ethical approval. A three-step modified Delphi method was used for voting on 96 statements generated following literature consultation; 192 statements total (96/96 topical application/mouth rinsing). Round 1 contributors voted to "agree" or "disagree" with statements; 80% agreement was required to accept statements. In round 2, contributors voted to "support" or "change" their round 1 unaccepted statements, with knowledge of the extant voting from round 1. Round 3 contributors met to discuss voting against key remaining statements. RESULTS Forty-seven statements reached consensus in round 1 (30/17 topical application/rinsing); 14 proved redundant. Six statements reached consensus in round 2 (2/4 topical application/rinsing); 116 statements proved redundant. Nine further statements were agreed in round 3 (6/3 topical application/rinsing) with caveats. DISCUSSION Consensus was reached on 62 statements in total (38/24 topical application/rinsing), enabling the development of guidance on safe menthol administration, with a view to enhancing performance and perception in the heat without impairing body temperature regulation.
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Affiliation(s)
- M J Barwood
- Department of Sport, Health and Nutrition, Leeds Trinity University, Brownberrie Lane, Horsforth, Leeds, LS18 5HD, UK.
| | - O R Gibson
- Centre for Human Performance, Exercise and Rehabilitation (CHPER), Department Life Sciences, Division of Sport, Health and Exercise Sciences, Brunel University London, Kingston Lane, Uxbridge, UB8 3PH, UK
| | - D J Gillis
- Human Performance Laboratory, Department of Sport and Movement Science, Salem State University, Salem, MA, 01970, USA
| | - O Jeffries
- School of Biomedical, Nutritional and Sport Sciences, Faculty of Medical Sciences, Newcastle University, Catherine Cookson Building, Newcastle Upon Tyne, NE2 4HH, UK
| | - N B Morris
- Department of Nutrition, Exercise and Sports, University of Copenhagen, 2100, Copenhagen, Denmark
| | - J Pearce
- Performance Nutrition Technical Lead, High Performance Sport New Zealand, Auckland, New Zealand
| | - M L Ross
- Australian Institute of Sport, Bruce, 2617, Australia
- Mary Mackillop Institute for Health Research, Australian Catholic University, Melbourne, 3000, Australia
| | - C Stevens
- School of Health and Human Sciences, Southern Cross University, Hogbin Dr, Coffs Harbour, NSW, 2450, Australia
| | - K Rinaldi
- Laboratoire ACTES (EA3596), Université des Antilles et de la Guyane, BP 250, 97157, Pointe-à-Pitre, France
- Arkea Samsic Pro Cycling Team, 35170, Bruz, France
| | - S N Kounalakis
- Faculty of Physical and Cultural Education, Evelpidon Hellenic Army Academy, Vari, Greece
| | - F Riera
- UPRES EA 35-96, UFR-STAPS, Université des Antilles et de la Guyane, BP 250, 97157, Pointe à Pitre Cedex, France
- Laboratoire Performance Santé Altitude, Université de Perpignan Via Domitia, UFR Sciences et Techniques des Activités Physiques et Sportives, 7 avenue Pierre de Coubertin, 66120, Font-Romeu, France
| | - T Mündel
- School of Sport Exercise and Nutrition, Massey University, Palmerston, New Zealand
| | - M Waldron
- College of Engineering, Applied Sports Science Technology and Medicine Research Centre (A-STEM), Swansea University Bay Campus, Swansea, Wales, UK
- School of Science and Technology, University of New England, Armidale, NSW, Australia
| | - R Best
- Centre for Sport Science and Human Performance, Waikato Institute of Technology, Hamilton, 3200, New Zealand
- School of Health and Social Care, Teesside University, Middlesbrough, Tees Valley, TS1 3BX, UK
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12
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Wright TA, Parry C, Gibson OR, Francis-Jones RJA, Mosley PJ. Resource-efficient frequency conversion for quantum networks via sequential four-wave mixing. Opt Lett 2020; 45:4587-4590. [PMID: 32797016 DOI: 10.1364/ol.398408] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 07/10/2020] [Indexed: 06/11/2023]
Abstract
We report a resource-efficient scheme in which a single pump laser was used to achieve frequency conversion by Bragg-scattering four-wave mixing in a photonic crystal fiber. We demonstrate bidirectional conversion of coherent light between Sr+2P1/2→2D3/2 emission wavelength at 1092 nm and the telecommunication C band with conversion efficiencies of 4.2% and 37% for up- and down-conversion, respectively. We discuss how the scheme may be viably scaled to meet the temporal, spectral, and polarization stability requirements of a hybrid light-matter quantum network.
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Walter E, Gibson OR. The efficacy of steroids in reducing morbidity and mortality from extreme hyperthermia and heatstroke-A systematic review. Pharmacol Res Perspect 2020; 8:e00626. [PMID: 32666709 PMCID: PMC7360483 DOI: 10.1002/prp2.626] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 06/19/2020] [Accepted: 06/22/2020] [Indexed: 12/09/2022] Open
Abstract
Severe hyperthermia from classical or exertional heatstroke, or from drug ingestion or other noninfective pyrogens, is associated with a high mortality and morbidity. A systemic pro-inflammatory response occurs during heatstroke, characterized by elevated cytokines with endotoxemia from elevated lipopolysaccharide (LPS) levels. Corticosteroids reduce LPS and cytokine levels, suggesting that they may improve outcome. A systematic review searching Embase, MEDLINE, and PubMed from the earliest date available until September 2019 was conducted, according to the PRISMA guidelines, with five papers identified. In four studies, systemic steroids administered before or at the onset of heat stress improved mortality or reduced organ dysfunction. Survival time was greatest when steroid administration preceded heat stress. In one study, a nonsignificant increase in mortality was seen. A dose response was observed, with higher doses extending survival time. Animal studies suggest that steroids improve mortality and/or organ dysfunction after an episode of heat stress or extreme hyperthermia.
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Affiliation(s)
- Edward Walter
- Intensive Care UnitRoyal Surrey County HospitalGuildfordUK
| | - Oliver R. Gibson
- Division of Sport, Health and Exercise SciencesCentre for Human Performance, Exercise and Rehabilitation (CHPER)Brunel University LondonUxbridgeUK
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14
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Hunt AP, Minett GM, Gibson OR, Kerr GK, Stewart IB. Could Heat Therapy Be an Effective Treatment for Alzheimer's and Parkinson's Diseases? A Narrative Review. Front Physiol 2020; 10:1556. [PMID: 31998141 PMCID: PMC6965159 DOI: 10.3389/fphys.2019.01556] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 12/10/2019] [Indexed: 12/11/2022] Open
Abstract
Neurodegenerative diseases involve the progressive deterioration of structures within the central nervous system responsible for motor control, cognition, and autonomic function. Alzheimer's disease and Parkinson's disease are among the most common neurodegenerative disease and have an increasing prevalence over the age of 50. Central in the pathophysiology of these neurodegenerative diseases is the loss of protein homeostasis, resulting in misfolding and aggregation of damaged proteins. An element of the protein homeostasis network that prevents the dysregulation associated with neurodegeneration is the role of molecular chaperones. Heat shock proteins (HSPs) are chaperones that regulate the aggregation and disaggregation of proteins in intracellular and extracellular spaces, and evidence supports their protective effect against protein aggregation common to neurodegenerative diseases. Consequently, upregulation of HSPs, such as HSP70, may be a target for therapeutic intervention for protection against neurodegeneration. A novel therapeutic intervention to increase the expression of HSP may be found in heat therapy and/or heat acclimation. In healthy populations, these interventions have been shown to increase HSP expression. Elevated HSP may have central therapeutic effects, preventing or reducing the toxicity of protein aggregation, and/or peripherally by enhancing neuromuscular function. Broader physiological responses to heat therapy have also been identified and include improvements in muscle function, cerebral blood flow, and markers of metabolic health. These outcomes may also have a significant benefit for people with neurodegenerative disease. While there is limited research into body warming in patient populations, regular passive heating (sauna bathing) has been associated with a reduced risk of developing neurodegenerative disease. Therefore, the emerging evidence is compelling and warrants further investigation of the potential benefits of heat acclimation and passive heat therapy for sufferers of neurodegenerative diseases.
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Affiliation(s)
- Andrew P. Hunt
- School of Exercise and Nutrition Sciences, Faculty of Health, Queensland University of Technology, Brisbane, QLD, Australia
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia
| | - Geoffrey M. Minett
- School of Exercise and Nutrition Sciences, Faculty of Health, Queensland University of Technology, Brisbane, QLD, Australia
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia
| | - Oliver R. Gibson
- Centre for Human Performance, Exercise and Rehabilitation, College of Health and Life Sciences, Brunel University London, Uxbridge, United Kingdom
- Division of Sport, Health and Exercise Sciences, Department of Life Sciences, College of Health and Life Sciences, Brunel University London, Uxbridge, United Kingdom
| | - Graham K. Kerr
- School of Exercise and Nutrition Sciences, Faculty of Health, Queensland University of Technology, Brisbane, QLD, Australia
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia
| | - Ian B. Stewart
- School of Exercise and Nutrition Sciences, Faculty of Health, Queensland University of Technology, Brisbane, QLD, Australia
- Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia
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15
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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: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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16
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Willmott AGB, Hayes M, James CA, Gibson OR, Maxwell NS. Heat acclimation attenuates the increased sensations of fatigue reported during acute exercise-heat stress. Temperature (Austin) 2019; 7:178-190. [PMID: 33015245 PMCID: PMC7518764 DOI: 10.1080/23328940.2019.1664370] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Revised: 08/30/2019] [Accepted: 08/30/2019] [Indexed: 12/19/2022] Open
Abstract
Athletes exercising in heat stress experience increased perceived fatigue acutely, however it is unknown whether heat acclimation (HA) reduces the magnitude of this perceptual response and whether different HA protocols influence the response. This study investigated sensations of fatigue following; acute exercise-heat stress; short- (5-sessions) and medium-term (10-sessions) HA; and between once- (ODHA) and twice-daily HA (TDHA) protocols. Twenty male participants (peak oxygen uptake: 3.75 ± 0.47 L·min-1) completed 10 sessions (60-min cycling at ~2 W·kg-1, 45°C/20% relative humidity) of ODHA (n = 10) or non-consecutive TDHA (n = 10). Sensations of fatigue (General, Physical, Emotional, Mental, Vigor and Total Fatigue) were assessed using the multi-dimensional fatigue scale inventory-short form pre and post session 1, 5 and 10. Heat adaptation was induced following ODHA and TDHA, with reductions in resting rectal temperature and heart rate, and increased plasma volume and sweat rate (P < 0.05). General, Physical and Total Fatigue increased from pre-to-post for session 1 within both groups (P < 0.05). Increases in General, Physical and Total Fatigue were attenuated in session 5 and 10 vs. session 1 of ODHA (P < 0.05). This change only occurred at session 10 of TDHA (P < 0.05). Whilst comparative heat adaptations followed ODHA and TDHA, perceived fatigue is prolonged within TDHA. ABBREVIATIONS ∆: Change; ANOVA: Analysis of variance; HA: Heat acclimation; HR: Heart rate; IL-6: Interleukin-6; MFS-SF: Multi-dimensional fatigue symptom inventory-short form (MFSI-SF); MTHA: Medium-term heat acclimation; Na+: Sodium; ODHA: Once daily heat acclimation; PV: Plasma volume; RH: Relative humidity; RPE: Rating of perceived exertion; SD: Standard deviation; SE: Standard error of the slope coefficient or intercept; SEE : Standard error of the estimate for the regression equation; STHA: Short-term heat acclimation; TDHA: Twice daily heat acclimation; TC: Thermal Comfort; Tre: Rectal temperature; TSS: Thermal sensation; V̇O2peak: Peak oxygen uptake; WBSL: whole-body sweat loss.
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Affiliation(s)
- Ashley G B Willmott
- Centre for Sport and Exercise Science, Anglia Ruskin University, Cambridge, UK
- Environmental Extremes Laboratory, University of Brighton, Eastbourne, UK
| | - Mark Hayes
- Environmental Extremes Laboratory, University of Brighton, Eastbourne, UK
| | - Carl A. James
- Environmental Extremes Laboratory, University of Brighton, Eastbourne, UK
- Physiology Department, Institut Sukan Negara (National Sports Institute), Kuala Lumpur, Malaysia
| | - Oliver R. Gibson
- Centre for Human Performance, Exercise and Rehabilitation (CHPER), Brunel University London, London, UK
| | - Neil S. Maxwell
- Environmental Extremes Laboratory, University of Brighton, Eastbourne, UK
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17
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Lee BJ, Gibson OR, Thake CD, Tipton M, Hawley JA, Cotter JD. Editorial: Cross Adaptation and Cross Tolerance in Human Health and Disease. Front Physiol 2019; 9:1827. [PMID: 30670977 PMCID: PMC6331449 DOI: 10.3389/fphys.2018.01827] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 12/06/2018] [Indexed: 11/13/2022] Open
Affiliation(s)
- Ben James Lee
- Occupational Performance Research Group, Institute of Sport, University of Chichester, Chichester, United Kingdom
| | - Oliver R Gibson
- Department of Life Sciences, Centre for Human Performance, Exercise and Rehabilitation, Brunel University London, Uxbridge, United Kingdom
| | | | - Mike Tipton
- Extreme Environments Laboratory, Department of Sport and Exercise Science, University of Portsmouth, Portsmouth, United Kingdom
| | - John A Hawley
- Mary MacKillop Institute for Health Research, Australian Catholic University, Melbourne, VIC, Australia
| | - James David Cotter
- School of Physical Education, Sport and Exercise Sciences, University of Otago, Otago, New Zealand
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Gibson OR, Wrightson JG, Hayes M. Intermittent sprint performance in the heat is not altered by augmenting thermal perception via L-menthol or capsaicin mouth rinses. Eur J Appl Physiol 2018; 119:653-664. [PMID: 30580384 PMCID: PMC6394657 DOI: 10.1007/s00421-018-4055-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Accepted: 12/10/2018] [Indexed: 11/18/2022]
Abstract
Purpose Cooling sensations elicited by mouth rinsing with L-menthol have been reported as ergogenic. Presently, responses to L-menthol mouth rinsing during intermittent sprint performance (ISP) in the heat are unknown and the impact of increased thermal perception on ISP via capsaicin has also not been quantified. This experiment aimed to identify whether eliciting cooling/warming sensations via L-menthol/capsaicin would alter ISP in the heat. Method Fourteen participants (mass = 72 ± 9 kg, \documentclass[12pt]{minimal}
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\begin{document}$$\dot {V}{{\text{O}}_{2{\text{peak}}}}$$\end{document}V˙O2peak = 3.30 ± 0.90 L min−1), undertook four experimental trials, involving 40 min of ISP in hot conditions (40.2 ± 0.6 °C, 42 ± 2% R.H.) with mouth rinsing (25 mL, 6 s) at the protocol onset, and every 10 min thereafter. Cooling (0.01% L-menthol; MEN), warming (0.2% capsaicin; CAP), placebo (0.3 sham-CHO; PLA), and control (water; CON) mouth rinses were utilized. Performance was quantified via power (PP) and work done (WD) during sprints. Heart rate (HR), core (Trec) and skin (Tskin) temperature, perceived exertion (RPE), thermal sensation (Tsens), and comfort (Tcom) were measured at 10 min intervals. Sweat rate (whole-body sweat rate) was calculated from ∆mass. Result PP reduced over time (P < 0.05); however, no change was observed between trials for PP or WD (P > 0.05). Tcom increased over time and was lower in MEN (2.7 ± 1.1; P < 0.05) with no difference between CAP (3.1 ± 1.2), PLA (3.2 ± 1.3) and CON (3.1 ± 1.3). RPE, Tsens HR, Trec, and Tskin increased over time (P < 0.05) with no between trial differences (P > 0.05). Conclusion Despite improved thermal comfort via L-menthol, ISP did not improve. Capsaicin did not alter thermal perception or ISP. The reduction in ISP over time in hot conditions is not influenced by thermal perception. Electronic supplementary material The online version of this article (10.1007/s00421-018-4055-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- O R Gibson
- Centre for Human Performance, Exercise and Rehabilitation, College of Health and Life Sciences, Brunel University London, Uxbridge, UK. .,Division of Sport, Health and Exercise Sciences, Department of Life Sciences, College of Health and Life Sciences, Brunel University London, Uxbridge, UK.
| | - J G Wrightson
- Faculty of Kinesiology, University of Calgary, Calgary, Canada
| | - M Hayes
- Environmental Extremes Laboratory, University of Brighton, Eastbourne, UK
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Willmott AGB, Hayes M, James CA, Dekerle J, Gibson OR, Maxwell NS. Once- and twice-daily heat acclimation confer similar heat adaptations, inflammatory responses and exercise tolerance improvements. Physiol Rep 2018; 6:e13936. [PMID: 30575321 PMCID: PMC6302546 DOI: 10.14814/phy2.13936] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 11/08/2018] [Indexed: 11/29/2022] Open
Abstract
This experiment aimed to investigate the efficacy of twice-daily, nonconsecutive heat acclimation (TDHA) in comparison to once-daily heat acclimation (ODHA) and work matched once- or twice-daily temperate exercise (ODTEMP, TDTEMP) for inducing heat adaptations, improved exercise tolerance, and cytokine (immune) responses. Forty males, matched biophysically and for aerobic capacity, were assigned to ODHA, TDHA, ODTEMP, or TDTEMP. Participants completed a cycling-graded exercise test, heat acclimation state test, and a time to task failure (TTTF) at 80% peak power output in temperate (TTTFTEMP : 22°C/40% RH) and hot conditions (TTTFHOT : 38°C/20% RH), before and after 10-sessions (60 min of cycling at ~2 W·kg-1 ) in 45°C/20% RH (ODHA and TDHA) or 22°C/40% RH (ODTEMP or TDTEMP). Plasma IL-6, TNF-α, and cortisol were measured pre- and postsessions 1, 5, and 10. ODHA and TDHA induced equivalent heat adaptations (P < 0.05) (resting rectal temperature [-0.28 ± 0.22, -0.28 ± 0.19°C], heart rate [-10 ± 3, -10 ± 4 b·min-1 ], and plasma volume expansion [+10.1 ± 5.6, +8.5 ± 3.1%]) and improved heat acclimation state (sweat set point [-0.22 ± 0.18, -0.22 ± 0.14°C] and gain [+0.14 ± 0.10, +0.15 ± 0.07 g·sec-1 ·°C-1 ]). TTTFHOT increased (P < 0.001) following ODHA (+25 ± 4%) and TDHA (+24 ± 10%), but not ODTEMP (+5 ± 14%) or TDTEMP (+5 ± 17%). TTTFTEMP did not improve (P > 0.05) following ODHA (+14 ± 4%), TDHA (14 ± 8%), ODTEMP (9 ± 10%) or TDTEMP (8 ± 13%). Acute (P < 0.05) but no chronic (P > 0.05) increases were observed in IL-6, TNF-α, or cortisol during ODHA and TDHA, or ODTEMP and TDTEMP. Once- and twice-daily heat acclimation conferred similar magnitudes of heat adaptation and exercise tolerance improvements, without differentially altering immune function, thus nonconsecutive TDHA provides an effective, logistically flexible method of HA, benefitting individuals preparing for exercise-heat stress.
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Affiliation(s)
- Ashley G. B. Willmott
- Environmental Extremes LaboratoryUniversity of BrightonBrightonEastbourneUnited Kingdom
| | - Mark Hayes
- Environmental Extremes LaboratoryUniversity of BrightonBrightonEastbourneUnited Kingdom
| | - Carl A. James
- Environmental Extremes LaboratoryUniversity of BrightonBrightonEastbourneUnited Kingdom
- Institut Sukan Negara (National Sports Institute)National Sports ComplexKuala LumpurMalaysia
| | - Jeanne Dekerle
- Environmental Extremes LaboratoryUniversity of BrightonBrightonEastbourneUnited Kingdom
| | - Oliver R. Gibson
- Centre for Human Performance, Exercise and Rehabilitation (CHPER)Brunel University LondonUxbridgeUnited Kingdom
| | - Neil S. Maxwell
- Environmental Extremes LaboratoryUniversity of BrightonBrightonEastbourneUnited Kingdom
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Abstract
To prepare for extremes of heat, cold or low partial pressures of oxygen (O2), humans can undertake a period of acclimation or acclimatization to induce environment-specific adaptations, e.g. heat acclimation (HA), cold acclimation (CA), or altitude training. While these strategies are effective, they are not always feasible due to logistical impracticalities. Cross-adaptation is a term used to describe the phenomenon whereby alternative environmental interventions, e.g. HA or CA, may be a beneficial alternative to altitude interventions, providing physiological stress and inducing adaptations observable at altitude. HA can attenuate physiological strain at rest and during moderate-intensity exercise at altitude via adaptations allied to improved O2 delivery to metabolically active tissue, likely following increases in plasma volume and reductions in body temperature. CA appears to improve physiological responses to altitude by attenuating the autonomic response to altitude. While no cross-acclimation-derived exercise performance/capacity data have been measured following CA, post-HA improvements in performance underpinned by aerobic metabolism, and therefore dependent on O2 delivery at altitude, are likely. At a cellular level, heat shock protein responses to altitude are attenuated by prior HA, suggesting that an attenuation of the cellular stress response and therefore a reduced disruption to homeostasis at altitude has occurred. This process is known as cross-tolerance. The effects of CA on markers of cross-tolerance is an area requiring further investigation. Because much of the evidence relating to cross-adaptation to altitude has examined the benefits at moderate to high altitudes, future research examining responses at lower altitudes should be conducted, given that these environments are more frequently visited by athletes and workers. Mechanistic work to identify the specific physiological and cellular pathways responsible for cross-adaptation between heat and altitude, and between cold and altitude, is warranted, as is exploration of benefits across different populations and physical activity profiles.
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Affiliation(s)
- Oliver R Gibson
- Centre for Human Performance, Exercise and Rehabilitation (CHPER), Brunel University London, Uxbridge, UK. .,Welkin Human Performance Laboratories, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Denton Road, Eastbourne, UK.
| | - Lee Taylor
- Athlete Health and Performance Research Centre, ASPETAR, Qatar Orthopaedic and Sports Medicine Hospital, Doha, Qatar.,School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
| | - Peter W Watt
- Welkin Human Performance Laboratories, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Denton Road, Eastbourne, UK
| | - Neil S Maxwell
- Welkin Human Performance Laboratories, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Denton Road, Eastbourne, UK
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James CA, Richardson AJ, Watt PW, Willmott AGB, Gibson OR, Maxwell NS. Short-Term Heat Acclimation and Precooling, Independently and Combined, Improve 5-km Time Trial Performance in the Heat. J Strength Cond Res 2018; 32:1366-1375. [PMID: 28486332 DOI: 10.1519/jsc.0000000000001979] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
James, CA, Richardson, AJ, Watt, PW, Willmott, AGB, Gibson, OR, and Maxwell, NS. Short-term heat acclimation and precooling, independently and combined, improve 5-km time trial performance in the heat. J Strength Cond Res 32(5): 1366-1375, 2018-Following heat acclimation (HA), endurance running performance remains impaired in hot vs. temperate conditions. Combining HA with precooling (PC) demonstrates no additive benefit in intermittent sprint, or continuous cycling exercise protocols, during which heat strain may be less severe compared to endurance running. This study investigated the effect of short-term HA (STHA) combined with mixed methods PC, on endurance running performance and directly compared PC and HA. Nine amateur trained runners completed 5-km treadmill time trials (TTs) in the heat (32° C, 60% relative humidity) under 4 conditions; no intervention (CON), PC, short-term HA (5 days-HA) and STHA with PC (HA + PC). Mean (±SD) performance times were; CON 1,476 (173) seconds, PC 1,421 (146) seconds, HA 1,378 (116) seconds and HA + PC 1,373 (121) seconds. This equated to the following improvements versus CON; PC -3.7%, HA -6.6% and HA + PC -7.0%. Statistical differences were only observed between HA and CON (p = 0.004, d = 0.68, 95% CI [-0.27 to 1.63]) however, similar effect sizes were observed for HA + PC vs. CON (d = 0.70, 95% CI [-0.25 to 1.65]), with smaller effects between PC vs. CON (d = 0.34, 95% CI [-0.59 to 1.27]), HA vs. PC (d = 0.33, 95% CI [-0.60 to 1.26]) and HA + PC vs. PC (d = 0.36, 95% CI [-0.57 to 1.29]). Pilot testing revealed a TT typical error of 16 seconds (1.2%). Precooling offered no further benefit to performance in the acclimated individual, despite modest alleviation of physiological strain. Maintenance of running speed in HA + PC, despite reduced physiological strain, may indicate an inappropriate pacing strategy therefore, further familiarization is recommended to optimize a combined strategy. Finally, these data indicate HA, achieved through cycle training, yields a larger ergogenic effect than PC on 5-km running performance in the heat, although PC remains beneficial when HA is not possible.
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Affiliation(s)
- Carl A James
- Environmental Extremes Laboratory, Center for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Eastbourne, United Kingdom.,National Sports Institute, Kompleks Sukan Negara, Kuala Lumpur, Malaysia
| | - Alan J Richardson
- Environmental Extremes Laboratory, Center for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Eastbourne, United Kingdom
| | - Peter W Watt
- Environmental Extremes Laboratory, Center for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Eastbourne, United Kingdom
| | - Ashley G B Willmott
- Environmental Extremes Laboratory, Center for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Eastbourne, United Kingdom
| | - Oliver R Gibson
- Center for Human Performance, Exercise and Rehabilitation (CHPER), Brunel University London, London, United Kingdom
| | - Neil S Maxwell
- Environmental Extremes Laboratory, Center for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Eastbourne, United Kingdom
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Barrington JH, Chrismas BCR, Gibson OR, Tuttle J, Pegrum J, Govilkar S, Kabir C, Giannakakis N, Rayan F, Okasheh Z, Sanaullah A, Ng Man Sun S, Pearce O, Taylor L. Hypoxic Air Inhalation and Ischemia Interventions Both Elicit Preconditioning Which Attenuate Subsequent Cellular Stress In vivo Following Blood Flow Occlusion and Reperfusion. Front Physiol 2017; 8:560. [PMID: 28824456 PMCID: PMC5539087 DOI: 10.3389/fphys.2017.00560] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 07/18/2017] [Indexed: 12/17/2022] Open
Abstract
Ischemic preconditioning (IPC) is valid technique which elicits reductions in femoral blood flow occlusion mediated reperfusion stress (oxidative stress, Hsp gene transcripts) within the systemic blood circulation and/or skeletal muscle. It is unknown whether systemic hypoxia, evoked by hypoxic preconditioning (HPC) has efficacy in priming the heat shock protein (Hsp) system thus reducing reperfusion stress following blood flow occlusion, in the same manner as IPC. The comparison between IPC and HPC being relevant as a preconditioning strategy prior to orthopedic surgery. In an independent group design, 18 healthy men were exposed to 40 min of (1) passive whole-body HPC (FiO2 = 0.143; no ischemia. N = 6), (2) IPC (FiO2 = 0.209; four bouts of 5 min ischemia and 5 min reperfusion. n = 6), or (3) rest (FiO2 = 0.209; no ischemia. n = 6). The interventions were administered 1 h prior to 30 min of tourniquet derived femoral blood flow occlusion and were followed by 2 h subsequent reperfusion. Systemic blood samples were taken pre- and post-intervention. Systemic blood and gastrocnemius skeletal muscle samples were obtained pre-, 15 min post- (15PoT) and 120 min (120PoT) post-tourniquet deflation. To determine the cellular stress response gastrocnemius and leukocyte Hsp72 mRNA and Hsp32 mRNA gene transcripts were determined by RT-qPCR. The plasma oxidative stress response (protein carbonyl, reduced glutathione/oxidized glutathione ratio) was measured utilizing commercially available kits. In comparison to control, at 15PoT a significant difference in gastrocnemius Hsp72 mRNA was seen in HPC (−1.93-fold; p = 0.007) and IPC (−1.97-fold; p = 0.006). No significant differences were observed in gastrocnemius Hsp32 and Hsp72 mRNA, leukocyte Hsp72 and Hsp32 mRNA, or oxidative stress markers (p > 0.05) between HPC and IPC. HPC provided near identical amelioration of blood flow occlusion mediated gastrocnemius stress response (Hsp72 mRNA), compared to an established IPC protocol. This was seen independent of changes in systemic oxidative stress, which likely explains the absence of change in Hsp32 mRNA transcripts within leukocytes and the gastrocnemius. Both the established IPC and novel HPC interventions facilitate a priming of the skeletal muscle, but not leukocyte, Hsp system prior to femoral blood flow occlusion. This response demonstrates a localized tissue specific adaptation which may ameliorate reperfusion stress.
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Affiliation(s)
- James H Barrington
- Institute of Sport and Physical Activity Research, University of BedfordshireLuton, United Kingdom
| | - Bryna C R Chrismas
- Sport Science Program, College of Arts and Sciences, Qatar UniversityDoha, Qatar
| | - Oliver R Gibson
- Division of Sport, Health and Exercise Sciences, Department of Life Sciences, Centre for Human Performance, Exercise and Rehabilitation, Brunel University LondonUxbridge, United Kingdom
| | - James Tuttle
- Institute of Sport and Physical Activity Research, University of BedfordshireLuton, United Kingdom
| | - J Pegrum
- Milton Keynes University HospitalMilton Keynes, United Kingdom
| | - S Govilkar
- Milton Keynes University HospitalMilton Keynes, United Kingdom
| | - Chindu Kabir
- Milton Keynes University HospitalMilton Keynes, United Kingdom
| | - N Giannakakis
- Milton Keynes University HospitalMilton Keynes, United Kingdom
| | - F Rayan
- Milton Keynes University HospitalMilton Keynes, United Kingdom
| | - Z Okasheh
- Milton Keynes University HospitalMilton Keynes, United Kingdom
| | - A Sanaullah
- Milton Keynes University HospitalMilton Keynes, United Kingdom
| | - S Ng Man Sun
- Milton Keynes University HospitalMilton Keynes, United Kingdom
| | - Oliver Pearce
- Milton Keynes University HospitalMilton Keynes, United Kingdom
| | - Lee Taylor
- ASPETAR, Athlete Health and Performance Research Centre, Qatar Orthopedic and Sports Medicine HospitalDoha, Qatar.,School of Sport, Exercise and Health Sciences. Loughborough UniversityLoughborough, United Kingdom
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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: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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James CA, Hayes M, Willmott AGB, Gibson OR, Flouris AD, Schlader ZJ, Maxwell NS. Defining the determinants of endurance running performance in the heat. Temperature (Austin) 2017; 4:314-329. [PMID: 28944273 PMCID: PMC5605161 DOI: 10.1080/23328940.2017.1333189] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 05/16/2017] [Accepted: 05/16/2017] [Indexed: 10/25/2022] Open
Abstract
In cool conditions, physiologic markers accurately predict endurance performance, but it is unclear whether thermal strain and perceived thermal strain modify the strength of these relationships. This study examined the relationships between traditional determinants of endurance performance and time to complete a 5-km time trial in the heat. Seventeen club runners completed graded exercise tests (GXT) in hot (GXTHOT; 32°C, 60% RH, 27.2°C WBGT) and cool conditions (GXTCOOL; 13°C, 50% RH, 9.3°C WBGT) to determine maximal oxygen uptake (V̇O2max), running economy (RE), velocity at V̇O2max (vV̇O2max), and running speeds corresponding to the lactate threshold (LT, 2 mmol.l-1) and lactate turnpoint (LTP, 4 mmol.l-1). Simultaneous multiple linear regression was used to predict 5 km time, using these determinants, indicating neither GXTHOT (R2 = 0.72) nor GXTCOOL (R2 = 0.86) predicted performance in the heat as strongly has previously been reported in cool conditions. vV̇O2max was the strongest individual predictor of performance, both when assessed in GXTHOT (r = -0.83) and GXTCOOL (r = -0.90). The GXTs revealed the following correlations for individual predictors in GXTHOT; V̇O2maxr = -0.7, RE r = 0.36, LT r = -0.77, LTP r = -0.78 and in GXTCOOL; V̇O2maxr = -0.67, RE r = 0.62, LT r = -0.79, LTP r = -0.8. These data indicate (i) GXTHOT does not predict 5 km running performance in the heat as strongly as a GXTCOOL, (ii) as in cool conditions, vV̇O2max may best predict running performance in the heat.
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Affiliation(s)
- Carl A James
- Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Eastbourne, UK.,National Sports Institute of Malaysia (Institut Sukan Negara), Bukit Jalil Stadium, Kuala Lumpur, Malaysia
| | - Mark Hayes
- Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Eastbourne, UK
| | - Ashley G B Willmott
- Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Eastbourne, UK
| | - Oliver R Gibson
- Centre for Human Performance, Exercise and Rehabilitation (CHPER), Brunel University London, London, UK
| | - Andreas D Flouris
- FAME Laboratory, Department of Exercise Science, University of Thessaly, Trikala, Greece
| | - Zachary J Schlader
- Centre for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, NY, USA
| | - Neil S Maxwell
- Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Eastbourne, UK
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Gibson OR, Willmott AGB, James CA, Hayes M, Maxwell NS. Power Relative to Body Mass Best Predicts Change in Core Temperature During Exercise-Heat Stress. J Strength Cond Res 2017; 31:403-414. [PMID: 27359208 DOI: 10.1519/jsc.0000000000001521] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Gibson, OR, Willmott, AGB, James, CA, Hayes, M, and Maxwell, NS. Power relative to body mass best predicts change in core temperature during exercise-heat stress. J Strength Cond Res 31(2): 403-414, 2017-Controlling internal temperature is crucial when prescribing exercise-heat stress, particularly during interventions designed to induce thermoregulatory adaptations. This study aimed to determine the relationship between the rate of rectal temperature (Trec) increase, and various methods for prescribing exercise-heat stress, to identify the most efficient method of prescribing isothermic heat acclimation (HA) training. Thirty-five men cycled in hot conditions (40° C, 39% R.H.) for 29 ± 2 minutes. Subjects exercised at 60 ± 9% V[Combining Dot Above]O2peak, with methods for prescribing exercise retrospectively observed for each participant. Pearson product moment correlations were calculated for each prescriptive variable against the rate of change in Trec (° C·h), with stepwise multiple regressions performed on statistically significant variables (p ≤ 0.05). Linear regression identified the predicted intensity required to increase Trec by 1.0-2.0° C between 20- and 45-minute periods and the duration taken to increase Trec by 1.5° C in response to incremental intensities to guide prescription. Significant (p ≤ 0.05) relationships with the rate of change in Trec were observed for prescriptions based on relative power (W·kg; r = 0.764), power (%Powermax; r = 0.679), rating of perceived exertion (RPE) (r = 0.577), V[Combining Dot Above]O2 (%V[Combining Dot Above]O2peak; r = 0.562), heart rate (HR) (%HRmax; r = 0.534), and thermal sensation (r = 0.311). Stepwise multiple regressions observed relative power and RPE as variables to improve the model (r = 0.791), with no improvement after inclusion of any anthropometric variable. Prescription of exercise under heat stress using power (W·kg or %Powermax) has the strongest relationship with the rate of change in Trec with no additional requirement to correct for body composition within a normal range. Practitioners should therefore prescribe exercise intensity using relative power during isothermic HA training to increase Trec efficiently and maximize adaptation.
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Affiliation(s)
- Oliver R Gibson
- 1Center for Human Performance, Exercise and Rehabilitation (CHPER), Brunel University London, Uxbridge, United Kingdom; and 2Center for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Eastbourne, United Kingdom
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James CA, Richardson AJ, Watt PW, Willmott AG, Gibson OR, Maxwell NS. Short-term heat acclimation improves the determinants of endurance performance and 5-km running performance in the heat. Appl Physiol Nutr Metab 2017; 42:285-294. [DOI: 10.1139/apnm-2016-0349] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This study investigated the effect of 5 days of controlled short-term heat acclimation (STHA) on the determinants of endurance performance and 5-km performance in runners, relative to the impairment afforded by moderate heat stress. A control group (CON), matched for total work and power output (2.7 W·kg−1), differentiated thermal and exercise contributions of STHA on exercise performance. Seventeen participants (10 STHA, 7 CON) completed graded exercise tests (GXTs) in cool (13 °C, 50% relative humidity (RH), pre-training) and hot conditions (32 °C, 60% RH, pre- and post-training), as well as 5-km time trials (TTs) in the heat, pre- and post-training. STHA reduced resting (p = 0.01) and exercising (p = 0.04) core temperature alongside a smaller change in thermal sensation (p = 0.04). Both groups improved the lactate threshold (LT, p = 0.021), lactate turnpoint (LTP, p = 0.005) and velocity at maximal oxygen consumption (vV̇O2max; p = 0.031) similarly. Statistical differences between training methods were observed in TT performance (STHA, −6.2(5.5)%; CON, −0.6(1.7)%, p = 0.029) and total running time during the GXT (STHA, +20.8(12.7)%; CON, +9.8(1.2)%, p = 0.006). There were large mean differences in change in maximal oxygen consumption between STHA +4.0(2.2) mL·kg−1·min−1 (7.3(4.0)%) and CON +1.9(3.7) mL·kg−1·min−1 (3.8(7.2)%). Running economy (RE) deteriorated following both training programmes (p = 0.008). Similarly, RE was impaired in the cool GXT, relative to the hot GXT (p = 0.004). STHA improved endurance running performance in comparison with work-matched normothermic training, despite equality of adaptation for typical determinants of performance (LT, LTP, vV̇O2max). Accordingly, these data highlight the ergogenic effect of STHA, potentially via greater improvements in maximal oxygen consumption and specific thermoregulatory and associated thermal perception adaptations absent in normothermic training.
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Affiliation(s)
- Carl A. James
- Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Eastbourne BN20 7UR, UK
- National Sports Institute of Malaysia, Institut Sukan Negara, Bukit Jalil Stadium, Kuala Lumpur 57000, Malaysia
| | - Alan J. Richardson
- Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Eastbourne BN20 7UR, UK
| | - Peter W. Watt
- Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Eastbourne BN20 7UR, UK
| | - Ashley G.B. Willmott
- Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Eastbourne BN20 7UR, UK
| | - Oliver R. Gibson
- Centre for Human Performance, Exercise and Rehabilitation (CHPER), Brunel University London UB8 3PH, UK
| | - Neil S. Maxwell
- Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Eastbourne BN20 7UR, UK
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Willmott AGB, Hayes M, Waldock KAM, Relf RL, Watkins ER, James CA, Gibson OR, Smeeton NJ, Richardson AJ, Watt PW, Maxwell NS. Short-term heat acclimation prior to a multi-day desert ultra-marathon improves physiological and psychological responses without compromising immune status. J Sports Sci 2016; 35:2249-2256. [PMID: 27935427 DOI: 10.1080/02640414.2016.1265142] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Multistage, ultra-endurance events in hot, humid conditions necessitate thermal adaptation, often achieved through short term heat acclimation (STHA), to improve performance by reducing thermoregulatory strain and perceptions of heat stress. This study investigated the physiological, perceptual and immunological responses to STHA prior to the Marathon des Sables. Eight athletes (age 42 ± 4 years and body mass 81.9 ± 15.0 kg) completed 4 days of controlled hyperthermia STHA (60 min·day‒1, 45°C and 30% relative humidity). Pre, during and post sessions, physiological and perceptual measures were recorded. Immunological measures were recorded pre-post sessions 1 and 4. STHA improved thermal comfort (P = 0.02), sensation (P = 0.03) and perceived exertion (P = 0.04). A dissociated relationship between perceptual fatigue and Tre was evident after STHA, with reductions in perceived Physical (P = 0.04) and General (P = 0.04) fatigue. Exercising Tre and HR did not change (P > 0.05) however, sweat rate increased 14% (P = 0.02). No changes were found in white blood cell counts or content (P > 0.05). Four days of STHA facilitates effective perceptual adaptations, without compromising immune status prior to an ultra-endurance race in heat stress. A greater physiological strain is required to confer optimal physiological adaptations.
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Affiliation(s)
- Ashley G B Willmott
- a Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), Sport and Exercise Science Consultancy Unit (SESCU) , University of Brighton , Eastbourne , UK
| | - Mark Hayes
- a Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), Sport and Exercise Science Consultancy Unit (SESCU) , University of Brighton , Eastbourne , UK
| | - Kirsty A M Waldock
- a Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), Sport and Exercise Science Consultancy Unit (SESCU) , University of Brighton , Eastbourne , UK
| | - Rebecca L Relf
- a Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), Sport and Exercise Science Consultancy Unit (SESCU) , University of Brighton , Eastbourne , UK
| | - Emily R Watkins
- a Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), Sport and Exercise Science Consultancy Unit (SESCU) , University of Brighton , Eastbourne , UK
| | - Carl A James
- b National Sports Institute (Institut Sukan Negara) , National Sport Complex , Kuala Lumpur , Malaysia
| | - Oliver R Gibson
- c Centre for Human Performance, Exercise and Rehabilitation , Brunel University London , London , UK
| | - Nicholas J Smeeton
- a Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), Sport and Exercise Science Consultancy Unit (SESCU) , University of Brighton , Eastbourne , UK
| | - Alan J Richardson
- a Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), Sport and Exercise Science Consultancy Unit (SESCU) , University of Brighton , Eastbourne , UK
| | - Peter W Watt
- a Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), Sport and Exercise Science Consultancy Unit (SESCU) , University of Brighton , Eastbourne , UK
| | - Neil S Maxwell
- a Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), Sport and Exercise Science Consultancy Unit (SESCU) , University of Brighton , Eastbourne , UK
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Gibson OR, Tuttle JA, Watt PW, Maxwell NS, Taylor L. Hsp72 and Hsp90α mRNA transcription is characterised by large, sustained changes in core temperature during heat acclimation. Cell Stress Chaperones 2016; 21:1021-1035. [PMID: 27511024 PMCID: PMC5083671 DOI: 10.1007/s12192-016-0726-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Revised: 07/15/2016] [Accepted: 07/19/2016] [Indexed: 12/19/2022] Open
Abstract
Increased intracellular heat shock protein-72 (Hsp72) and heat shock protein-90α (Hsp90α) have been implicated as important components of acquired thermotolerance, providing cytoprotection during stress. This experiment determined the physiological responses characterising increases in Hsp72 and Hsp90α mRNA on the first and tenth day of 90-min heat acclimation (in 40.2 °C, 41.0 % relative humidity (RH)) or equivalent normothermic training (in 20 °C, 29 % RH). Pearson's product-moment correlation and stepwise multiple regression were performed to determine relationships between physiological [e.g. (Trec, sweat rate (SR) and heart rate (HR)] and training variables (exercise duration, exercise intensity, work done), and the leukocyte Hsp72 and Hsp90α mRNA responses via reverse transcription quantitative polymerase chain reaction (RT-QPCR) (n = 15). Significant (p < 0.05) correlations existed between increased Hsp72 and Hsp90α mRNA (r = 0.879). Increased core temperature was the most important criteria for gene transcription with ΔTrec (r = 0.714), SR (r = 0.709), Trecfinal45 (r = 0.682), area under the curve where Trec ≥ 38.5 °C (AUC38.5 °C; r = 0.678), peak Trec (r = 0.661), duration Trec ≥ 38.5 °C (r = 0.650) and ΔHR (r = 0.511) each demonstrating a significant (p < 0.05) correlation with the increase in Hsp72 mRNA. The Trec AUC38.5 °C (r = 0.729), ΔTrec (r = 0.691), peak Trec (r = 0.680), Trecfinal45 (r = 0.678), SR (r = 0.660), duration Trec ≥ 38.5 °C (r = 0.629), the rate of change in Trec (r = 0.600) and ΔHR (r = 0.531) were the strongest correlate with the increase in Hsp90α mRNA. Multiple regression improved the model for Hsp90α mRNA only, when Trec AUC38.5 °C and SR were combined. Training variables showed insignificant (p > 0.05) weak (r < 0.300) relationships with Hsp72 and Hsp90α mRNA. Hsp72 and Hsp90α mRNA correlates were comparable on the first and tenth day. When transcription of the related Hsp72 and Hsp90α mRNA is important, protocols should rapidly induce large, prolonged changes in core temperature.
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Affiliation(s)
- Oliver R Gibson
- Centre for Human Performance, Exercise and Rehabilitation (CHPER), Brunel University London, Uxbridge, UK.
- Centre for Sport and Exercise Science and Medicine (SESAME), Environmental Extremes Laboratory, Welkin Human Performance Laboratories, University of Brighton, Denton Road, Eastbourne, UK.
| | - James A Tuttle
- Muscle Cellular and Molecular Physiology (MCMP) and Applied Sport and Exercise Science (ASEP) Research Groups, Institute of Sport and Physical Activity Research (ISPAR), University of Bedfordshire, Bedford, UK
| | - Peter W Watt
- Centre for Sport and Exercise Science and Medicine (SESAME), Environmental Extremes Laboratory, Welkin Human Performance Laboratories, University of Brighton, Denton Road, Eastbourne, UK
| | - Neil S Maxwell
- Centre for Sport and Exercise Science and Medicine (SESAME), Environmental Extremes Laboratory, Welkin Human Performance Laboratories, University of Brighton, Denton Road, Eastbourne, UK
| | - Lee Taylor
- Athlete Health and Performance Research Centre, ASPETAR, Qatar Orthopaedic and Sports Medicine Hospital, Doha, Qatar
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
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Richardson AJ, Relf RL, Saunders A, Gibson OR. Similar Inflammatory Responses following Sprint Interval Training Performed in Hypoxia and Normoxia. Front Physiol 2016; 7:332. [PMID: 27536249 PMCID: PMC4971433 DOI: 10.3389/fphys.2016.00332] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 07/19/2016] [Indexed: 11/13/2022] Open
Abstract
Sprint interval training (SIT) is an efficient intervention capable of improving aerobic capacity and exercise performance. This experiment aimed to determine differences in training adaptations and the inflammatory responses following 2 weeks of SIT (30 s maximal work, 4 min recovery; 4-7 repetitions) performed in normoxia or hypoxia. Forty-two untrained participants [(mean ± SD), age 21 ±1 years, body mass 72.1 ±11.4 kg, and height 173 ±10 cm] were equally and randomly assigned to one of three groups; control (CONT; no training, n = 14), normoxic (NORM; SIT in FiO2: 0.21, n = 14), and normobaric hypoxic (HYP; SIT in FiO2: 0.15, n = 14). Participants completed a [Formula: see text] test, a time to exhaustion (TTE) trial (power = 80% [Formula: see text]) and had hematological [hemoglobin (Hb), haematocrit (Hct)] and inflammatory markers [interleukin-6 (IL-6), tumor necrosis factor-α (TNFα)] measured in a resting state, pre and post SIT. [Formula: see text] (mL.kg(-1).min(-1)) improved in HYP (+11.9%) and NORM (+9.8%), but not CON (+0.9%). Similarly TTE improved in HYP (+32.2%) and NORM (+33.0%), but not CON (+3.4%) whilst the power at the anaerobic threshold (AT; W.kg(-1)) also improved in HYP (+13.3%) and NORM (+8.0%), but not CON (-0.3%). AT (mL.kg(-1).min(-1)) improved in HYP (+9.5%), but not NORM (+5%) or CON (-0.3%). No between group change occurred in 30 s sprint performance or Hb and Hct. IL-6 increased in HYP (+17.4%) and NORM (+20.1%), but not CON (+1.2%), respectively. TNF-α increased in HYP (+10.8%) NORM (+12.9%) and CON (+3.4%). SIT in HYP and NORM increased [Formula: see text], power at AT and TTE performance in untrained individuals, improvements in AT occurred only when SIT was performed in HYP. Increases in IL-6 and TNFα reflect a training induced inflammatory response to SIT; hypoxic conditions do not exacerbate this.
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Affiliation(s)
- Alan J Richardson
- Environmental Extremes Lab, Centre for Sport and Exercise Science and Medicine, University of Brighton Eastbourne, UK
| | - Rebecca L Relf
- Environmental Extremes Lab, Centre for Sport and Exercise Science and Medicine, University of Brighton Eastbourne, UK
| | - Arron Saunders
- Environmental Extremes Lab, Centre for Sport and Exercise Science and Medicine, University of Brighton Eastbourne, UK
| | - Oliver R Gibson
- Centre for Human Performance, Exercise, and Rehabilitation, Brunel University London Uxbridge, UK
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Mee JA, Gibson OR, Tuttle JA, Taylor L, Watt PW, Doust J, Maxwell NS. Leukocyte Hsp72 mRNA transcription does not differ between males and females during heat acclimation. Temperature (Austin) 2016; 3:549-556. [PMID: 28090558 DOI: 10.1080/23328940.2016.1214336] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2016] [Revised: 07/12/2016] [Accepted: 07/13/2016] [Indexed: 12/31/2022] Open
Abstract
Purpose: Thermotolerance is an acquired state of increased cytoprotection achieved following single or repeated exposures to heat stress, in part characterized by changes in the intracellular 72 kda heat shock protein (HSP72; HSPA1A). Females have demonstrated reduced exercise induced HSP72 in comparison to males. This study examined sex differences in heat shock protein 72 messenger ribonucleic acid (Hsp72 mRNA) transcription during heat acclimation (HA) to identify whether sex differences were a result of differential gene transcription. Methods: Ten participants (5M, 5F) performed 10, 90 min controlled hyperthermia [rectal temperature (Tre) ≥ 38.5°C] HA sessions over 12 d. Leukocyte Hsp72 mRNA was measured pre and post D1, D5, and D10, via Reverse transcription polymerase chain reaction (RT-QPCR). Results: HA was evidenced by a reduction in resting Tre (-0.4 ± 0.5°C) and resting heart rate [(HR); -13 ± 7 beats.min-1] following HA (p ≤ 0.05). During HA no difference (p > 0.05) was observed in ΔTre between males (D1 = 1.5 ± 0.2°C; D5 = 1.6 ± 0.4°C; D10 = 1.8 ± 0.3°C) and females (D1 = 1.5 ± 0.5°C; D5 = 1.4 ± 0.2°C; D10 = 1.8 ± 0.3°C). This was also true of mean Tre demonstrating equality of thermal stimuli for mRNA transcription and HA. There were no differences (p > 0.05) in Hsp72 mRNA expression between HA sessions or between males (D1 = +1.8 ± 1.5-fold; D5 = +2.0 ± 1.0 fold; D10 = +1.1 ± 0.4-fold) and females (D1 = +2.6 ± 1.8-fold; D5 = +1.8 ± 1.4-fold; D10 = +0.9 ± 1.9-fold). Conclusions: This experiment demonstrates that there is no difference in Hsp72 mRNA increases during HA between sexes when controlled hyperthermia HA is utilised. Gender specific differences in exercise-induced HSP72 reported elsewhere likely result from post-transcriptional events.
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Affiliation(s)
- J A Mee
- Centre for Sport and Exercise Science and medicine (SESAME), Environmental Extremes Laboratory, University of Brighton, Welkin Human Performance Laboratories, Denton Road, Eastbourne, UK; School of Sport, Health, and Exercise Science, Bangor University, Bangor, UK
| | - O R Gibson
- Centre for Sport and Exercise Science and medicine (SESAME), Environmental Extremes Laboratory, University of Brighton, Welkin Human Performance Laboratories, Denton Road, Eastbourne, UK; Centre for Human Performance, Exercise and Rehabilitation (CHPER), Brunel University, London, UK
| | - J A Tuttle
- Muscle Cellular and Molecular Physiology (MCMP) and Applied Sport and Exercise Science (ASEP) Research Groups, Institute of Sport and Physical Activity Research (ISPAR), University of Bedfordshire , Bedford, UK
| | - L Taylor
- ASPETAR, Qatar Orthopaedic and Sports Medicine Hospital, Athlete Health and Performance Research Centre, Aspire Zone, Doha, Qatar; School of Sport, Exercise and Health Sciences. Loughborough University, Loughborough, UK
| | - P W Watt
- Centre for Sport and Exercise Science and medicine (SESAME), Environmental Extremes Laboratory, University of Brighton, Welkin Human Performance Laboratories , Denton Road , Eastbourne, UK
| | - J Doust
- Centre for Sport and Exercise Science and medicine (SESAME), Environmental Extremes Laboratory, University of Brighton, Welkin Human Performance Laboratories , Denton Road , Eastbourne, UK
| | - N S Maxwell
- Centre for Sport and Exercise Science and medicine (SESAME), Environmental Extremes Laboratory, University of Brighton, Welkin Human Performance Laboratories , Denton Road , Eastbourne, UK
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Ruddock AD, Thompson SW, Hudson SA, James CA, Gibson OR, Mee JA. Combined active and passive heat exposure induced heat acclimation in a soccer referee before 2014 FIFA World Cup. Springerplus 2016; 5:617. [PMID: 27330883 PMCID: PMC4870546 DOI: 10.1186/s40064-016-2298-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 05/06/2016] [Indexed: 11/10/2022]
Abstract
INTRODUCTION The 2014 FIFA World Cup was held in Brazil, where the climatic conditions presented a significant thermoregulatory and perceptual challenge to those unfamiliar with the heat and humidity. CASE PRESENTATION This case report documents the adaptation induced by a novel mixed methods (isothermic and passive) heat acclimation (HA) regime for a northern European professional soccer match official prior to the tournament. The intervention involved 13 HA sessions over an 18 day period comprising five isothermic HA sessions whereby intermittent running was used to target and maintain tympanic temperature (Tytemp) at 38 °C for 90 min, and seven passive HA sessions of 48 °C water bathing for 30 min. The athlete performed a heat stress test (HST) (35 min running at four incremental intensities in 30 °C) and a repeated high-intensity running test (as many 30 s self-paced efforts as possible, to a maximum of 20, with 30 s passive recovery) before and after the intervention. The mixed methods HA regime increased plasma volume (+7.1 %), and sweat loss (+0.9 L h(-1)), reduced exercising Tytemp (-0.6 °C), and mean body temperature (-0.5 °C). High-intensity running performance improved after HA (+29 %), as did the perception of thermal comfort during exercise (-0.3 units). CONCLUSION This data evidences the effectiveness of a practical, mixed methods HA strategy, remotely implemented around training and competition, at inducing the heat acclimation phenotype in a high-level soccer match official.
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Affiliation(s)
- A D Ruddock
- A016 Collegiate Hall, Centre for Sport and Exercise Science, Sheffield Hallam University, Sheffield, South Yorkshire S10 2BP UK
| | - S W Thompson
- Academy of Sport and Physical Activity, A209 Collegiate Hall, Sheffield Hallam University, Collegiate Crescent Campus, Eccelsall Road, Sheffield, S10 2BP UK
| | - S A Hudson
- Department of Sport, Health and Nutrition, Leeds Trinity University, Brownberrie Lane, Horsforth, Leeds, LS18 5HD UK
| | - C A James
- Environmental Extremes Laboratory, Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Welkin Laboratories, Denton Road, Eastbourne, East Sussex BN20 7SR UK
| | - O R Gibson
- Centre for Sports Medicine and Human Performance (CSMHP), Heinz Wolff Building, Brunel University London, Uxbridge, UB8 3PH UK
| | - J A Mee
- School of Sport and Health Sciences, George Building, Bangor University, Bangor, UK
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Taylor L, Lee BJ, Gibson OR, Midgley AW, Watt P, Mauger A, Castle P. Effective microorganism - X attenuates circulating superoxide dismutase following an acute bout of intermittent running in hot, humid conditions. Res Sports Med 2016; 24:130-44. [PMID: 27031165 DOI: 10.1080/15438627.2015.1126279] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
This study determined the effectiveness of antioxidant supplementation on high-intensity exercise-heat stress. Six males completed a high-intensity running protocol twice in temperate conditions (TEMP; 20.4°C), and twice in hot conditions (HOT; 34.7°C). Trials were completed following7 days supplementation with 70 ml·day(-1) effective microorganism-X (EM-X; TEMPEMX or HOTEMX) or placebo (TEMPPLA or HOTPLA). Plasma extracellular Hsp72 (eHsp72) and superoxide dismutase (SOD) were measured by ELISA. eHsp72 and SOD increased pre-post exercise (p < 0.001), with greater eHsp72 (p < 0.001) increases observed in HOT (+1.5 ng·ml(-1)) compared to TEMP (+0.8 ng·ml(-1)). EM-X did not influence eHsp72 (p > 0.05). Greater (p < 0.001) SOD increases were observed in HOT (+0.22 U·ml(-1)) versus TEMP (+0.10 U·ml(-1)) with SOD reduced in HOTEMX versus HOTPLA (p = 0.001). Physiological and perceptual responses were all greater (p < 0.001) in HOT versus TEMP conditions, with no difference followed EM-X (p > 0.05). EM-X supplementation attenuated the SOD increases following HOT, potentiating its application as an ergogenic aid to ameliorate oxidative stress.
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Affiliation(s)
- Lee Taylor
- a Applied Sport and Exercise Physiology (ASEP) Research Group, Institute of Sport and Physical Activity Research (ISPAR), Department of Sport and Exercise Sciences , University of Bedfordshire , Bedford , UK.,g ASPETAR, Qatar Orthopaedic and Sports Medicine Hospital , Athlete Health and Performance Research Centre , Doha , Qatar
| | - Ben J Lee
- b Department of Biomolecular and Sport Sciences , University of Coventry , Coventry , UK.,h Department for Health , University of Bath , Claverton Down , Bath , UK
| | - Oliver R Gibson
- c Centre for Sport and Exercise Science and Medicine (SESAME) , University of Brighton, Welkin Human Performance Laboratories , Denton Road, Eastbourne , UK.,i Centre for Sports Medicine and Human Performance (CSMHP) , Brunel University London , Uxbridge , UK
| | - Adrian W Midgley
- d Sport and Physical Activity Department , Edge Hill University , Ormskirk , United Kingdom
| | - Peter Watt
- c Centre for Sport and Exercise Science and Medicine (SESAME) , University of Brighton, Welkin Human Performance Laboratories , Denton Road, Eastbourne , UK
| | - Alexis Mauger
- e Endurance Research Group, School of Sport and Exercise Sciences , University of Kent , Chatham Maritime , UK
| | - Paul Castle
- f Muscle Cellular and Molecular Physiology (MCMP) & Applied Sport and Exercise Science(ASEP) Research Groups, Institute of Sport and Physical Activity Research (ISPAR), Department of Sport and Exercise Sciences , University of Bedfordshire , Bedford , UK
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Willmott AGB, Gibson OR, Hayes M, Maxwell NS. The effects of single versus twice daily short term heat acclimation on heat strain and 3000m running performance in hot, humid conditions. J Therm Biol 2016; 56:59-67. [PMID: 26857978 DOI: 10.1016/j.jtherbio.2016.01.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 01/04/2016] [Accepted: 01/04/2016] [Indexed: 10/22/2022]
Abstract
Endurance performances are impaired under conditions of elevated heat stress. Short term heat acclimation (STHA) over 4-6 days can evoke rapid adaptation, which mitigate decrements in performance and alleviate heat strain. This study investigated the efficacy of twice daily heat acclimation (TDHA) compared to single session per day heat acclimation (SDHA) and normothermic training, at inducing heat acclimation phenotype and its impact upon running performance in hot, humid conditions. Twenty one, moderately trained males were matched and assigned to three groups; SDHA (mean±SD) (peak oxygen consumption [V̇O2peak] 45.8±6.1mLkg(-1)min(-1), body mass 81.3±16.0kg, stature 182±3cm), TDHA (46.1±7.0mLkg(-1)min(-1), 80.1±11.9kg, 178±4cm) or control (CON) (47.1±3.5mLkg(-1)min(-1), 78.6±16.7kg, 178±4cm). Interventions consisted of 45min cycling at 50% V̇O2peak, once daily for 4d (SDHA) and twice daily for 2d (TDHA), in 35°C, 60% relative humidity (RH), and once daily for 4 days (CON) in 21°C, 40% RH. Participants completed a pre- and post-intervention 5km treadmill run trial in 30°C, 60% RH, where the first 2km were fixed at 40% V̇O2peak and the final 3km was self-paced. No statistically significant interaction effects occurred within- or between-groups over the 2-4 days intervention. While within-group differences were found in physiological and perceptual measures during the fixed intensity trial post-intervention, they did not statistically differ between-groups. Similarly, TDHA (-36±34s [+3.5%]) and SDHA (-26±28s [+2.8%]) groups improved 3km performances (p=0.35), but did not differ from CON (-6±44s [+0.6%]). This is the first study to investigate the effects of HA twice daily and compare it with traditional single session per day STHA. These STHA protocols may have the ability to induce partial adaptive responses to heat stress and possibly enhance performance in environmentally challenging conditions, however, future development is warranted to optimise the administration to provide a potent stimuli for heat adaptation in athletic and military personnel within a rapid regime.
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Affiliation(s)
- A G B Willmott
- Centre of Sport and Exercise Science and Medicine (SESAME), Environmental Extremes Laboratory, School of Sport and Service Management, University of Brighton, Eastbourne, UK.
| | - O R Gibson
- Centre of Sport and Exercise Science and Medicine (SESAME), Environmental Extremes Laboratory, School of Sport and Service Management, University of Brighton, Eastbourne, UK; Centre for Sports Medicine and Human Performance (CSMHP), Brunel University, London, UK
| | - M Hayes
- Centre of Sport and Exercise Science and Medicine (SESAME), Environmental Extremes Laboratory, School of Sport and Service Management, University of Brighton, Eastbourne, UK
| | - N S Maxwell
- Centre of Sport and Exercise Science and Medicine (SESAME), Environmental Extremes Laboratory, School of Sport and Service Management, University of Brighton, Eastbourne, UK
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Gibson OR, Watt PW, Maxwell NS. Prescribing workload administration to optimise isothermic heat acclimation. Extrem Physiol Med 2015. [PMCID: PMC4580885 DOI: 10.1186/2046-7648-4-s1-a83] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Gibson OR, Turner G, Tuttle JA, Taylor L, Watt PW, Maxwell NS. Heat acclimation attenuates physiological strain and the HSP72, but not HSP90α, mRNA response to acute normobaric hypoxia. J Appl Physiol (1985) 2015. [DOI: 10.1152/japplphysiol.00332.2015] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Heat acclimation (HA) attenuates physiological strain in hot conditions via phenotypic and cellular adaptation. The aim of this study was to determine whether HA reduced physiological strain, and heat shock protein (HSP) 72 and HSP90α mRNA responses in acute normobaric hypoxia. Sixteen male participants completed ten 90-min sessions of isothermic HA (40°C/40% relative humidity) or exercise training [control (CON); 20°C/40% relative humidity]. HA or CON were preceded (HYP1) and proceeded (HYP2) by a 30-min normobaric hypoxic exposure [inspired O2 fraction = 0.12; 10-min rest, 10-min cycling at 40% peak O2 uptake (V̇o2 peak), 10-min cycling at 65% V̇o2 peak]. HA induced greater rectal temperatures, sweat rate, and heart rates (HR) than CON during the training sessions. HA, but not CON, reduced resting rectal temperatures and resting HR and increased sweat rate and plasma volume. Hemoglobin mass did not change following HA nor CON. HSP72 and HSP90α mRNA increased in response to each HA session, but did not change with CON. HR during HYP2 was lower and O2 saturation higher at 65% V̇o2 peak following HA, but not CON. O2 uptake/HR was greater at rest and 65% V̇o2 peak in HYP2 following HA, but was unchanged after CON. At rest, the respiratory exchange ratio was reduced during HYP2 following HA, but not CON. The increase in HSP72 mRNA during HYP1 did not occur in HYP2 following HA. In CON, HSP72 mRNA expression was unchanged during HYP1 and HYP2. In HA and CON, increases in HSP90α mRNA during HYP1 were maintained in HYP2. HA reduces physiological strain, and the transcription of HSP72, but not HSP90α mRNA in acute normobaric hypoxia.
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Affiliation(s)
- Oliver R. Gibson
- Centre for Sport and Exercise Science and Medicine (SESAME), Environmental Extremes Laboratory, University of Brighton, Welkin Human Performance Laboratories, Eastbourne, United Kingdom
| | - Gareth Turner
- Centre for Sport and Exercise Science and Medicine (SESAME), Environmental Extremes Laboratory, University of Brighton, Welkin Human Performance Laboratories, Eastbourne, United Kingdom
- English Institute of Sport, EIS Performance Centre, Loughborough University, Loughborough, United Kingdom; and
| | - James A. Tuttle
- Muscle Cellular and Molecular Physiology (MCMP) and Applied Sport and Exercise Science (ASEP) Research Groups, Department of Sport Science and Physical Activity, Institute of Sport and Physical Activity Research (ISPAR), University of Bedfordshire, Bedfordshire, United Kingdom
| | - Lee Taylor
- Muscle Cellular and Molecular Physiology (MCMP) and Applied Sport and Exercise Science (ASEP) Research Groups, Department of Sport Science and Physical Activity, Institute of Sport and Physical Activity Research (ISPAR), University of Bedfordshire, Bedfordshire, United Kingdom
| | - Peter W. Watt
- Centre for Sport and Exercise Science and Medicine (SESAME), Environmental Extremes Laboratory, University of Brighton, Welkin Human Performance Laboratories, Eastbourne, United Kingdom
| | - Neil S. Maxwell
- Centre for Sport and Exercise Science and Medicine (SESAME), Environmental Extremes Laboratory, University of Brighton, Welkin Human Performance Laboratories, Eastbourne, United Kingdom
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Richardson AJ, Gibson OR. Simulated hypoxia does not further improve aerobic capacity during sprint interval training. J Sports Med Phys Fitness 2015; 55:1099-1106. [PMID: 25028984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
AIM The aim of this study was to investigate the use of hypoxic sprint interval training (SIT) for the improvement of aerobic capacity. METHOD Twenty-seven participants (mean±SD), age 21±1 yrs, body mass 72.4±9.7 kg and height 175±7 cm, completed an V̇O2peak Incremental Exercise Test and time to exhaustion (TTE) trial (80% V̇O2peak) pre and post SIT. Participants were randomly assigned to either, control (CONT), normoxic (NORM) or hypoxic (FiO2: 0.15) (HYP) conditions. SIT involved 30 s sprints interspersed with 4 min rest. The number of sprints progressed from four to seven over six sessions separated by 1-2 days rest. Two-way mixed design ANOVA was performed to determine changes between conditions. RESULTS V̇O2peak improved (P<0.05) pre to post SIT in NORM (11.2±10.8%) and HYP (10.9±6.2%), but not CONT (0.7±14.3%). TTE post SIT was significantly improved from pre SIT in NORM and HYP but not CONT (CONT=1±6, NORM=56±25, HYP=34±25%, P<0.05). Peak and recovery heart rate was lower in NORM (P<0.05) than HYP as SIT sessions progressed. SpO2 (%) was lower in HYP (86.1±4.3%) compared to NORM (97.1±0.7%), decreasing within all HYP sessions, and increasing with SIT. CONCLUSION Hypoxic and normoxic SIT caused improvement in V̇O2peak and TTE compared to a control. Hypoxic SIT did not cause further improvements, indicating hypoxia based SIT offers no additional benefit for improvement of endurance performance.
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Affiliation(s)
- A J Richardson
- Centre for Sport and Exercise Science and Medicine (SESAME), University of Brighton, Eastbourne, UK - a.j.
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Gibson OR, Richardson AJ, Hayes M, Duncan B, Maxwell NS. Prediction of physiological responses and performance at altitude using the 6-minute walk test in normoxia and hypoxia. Wilderness Environ Med 2015; 26:205-10. [PMID: 25772827 DOI: 10.1016/j.wem.2014.11.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Revised: 11/07/2014] [Accepted: 11/10/2014] [Indexed: 11/16/2022]
Abstract
OBJECTIVE The 6-minute walk test (6MWT) is a reliable and valid tool for determining an individual's functional capacity, and has been used to predict summit success. The primary aim of the study was to evaluate whether a 6MWT in normobaric hypoxia could predict physiological responses and exercise performance at altitude. The secondary aim was to determine construct validity of the 6MWT for monitoring acclimatization to 3400 m (Cuzco, Peru). METHODS Twenty-nine participants performed six 6MWTs in four conditions: normoxic outdoor (NO), normoxic treadmill (NT), and hypoxic treadmill (HT) were each performed once; and hypoxic outdoor (HO) was performed three times, at 42 hours (HO1), 138 hours (HO2), and 210 hours (HO3) after arrival at Cuzco. RESULTS One-way analysis of variance revealed no difference (P>.05) between NO and HO1 for 6MWT distance. HT and HO protocols were comparable for the measurement of delta heart rate (HR) and post-test peripheral oxygen saturation (%Spo2; P>.05). Acclimatization was evidenced by reductions (P<.05) in resting HR and respiratory rate (RR) between HO1, HO2, and HO3, and preservation of Spo2 between HO1 and HO2. Postexercise HR and RR were not different (P>.05) with acclimatization. The duration to ascend to 4215 m on a trek was moderately correlated (P<.05) to HR during the trek and the 6MWT distance during HT; no other physiological markers predicted performance. CONCLUSIONS The 6MWT is a simple, time-efficient tool for predicting physiological responses to simulated and actual altitude, which are comparable. The 6MWT is effective at monitoring elements of acclimatization to moderate altitude.
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Affiliation(s)
- Oliver R Gibson
- Centre for Sport and Exercise Science and Medicine (SESAME), Welkin Human Performance Laboratories, University of Brighton, UK.
| | - Alan J Richardson
- Centre for Sport and Exercise Science and Medicine (SESAME), Welkin Human Performance Laboratories, University of Brighton, UK
| | - Mark Hayes
- Centre for Sport and Exercise Science and Medicine (SESAME), Welkin Human Performance Laboratories, University of Brighton, UK
| | - Ben Duncan
- Centre for Sport and Exercise Science and Medicine (SESAME), Welkin Human Performance Laboratories, University of Brighton, UK
| | - Neil S Maxwell
- Centre for Sport and Exercise Science and Medicine (SESAME), Welkin Human Performance Laboratories, University of Brighton, UK
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Turner G, Gibson OR, Maxwell NS. Simulated moderate hypoxia reduces intermittent sprint performance in games players. J Sports Med Phys Fitness 2014; 54:566-574. [PMID: 25270776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
BACKGROUND Exercise at altitude places additional physiological stress on the individual in comparison with sea-level performance. This study examines the effect of a moderate hypoxic environment (FiO2=~17%) on intermittent sprint exercise performance. METHODS Nine male games players completed two consecutive sets of a 40 minute cycling intermittent sprint protocol (CISP×2) in a hypoxic (HYP; FiO2=~17%) and normoxic (NORM; FiO2=~21%) environment. During each sprint peak power output (PPO; the highest power during each 5 s sprint), mean power output (MPO; the average power during the 3 s sprint) were measured and total work done (WD; force applied from the highest 3 s period of power output) was calculated. Physiological responses were recorded throughout the testing procedure. RESULTS Reductions were found in PPO (944±155 vs. 983±167 W), MPO (900±176 vs. 853±177 W) and WD (102±20 vs. 108±20 kJ) during the CISP×2 (P<0.05) at HYP compared to NORM. Reductions in PPO, MPO and WD were also found between the 1st half and 2nd half CISP (P<0.05) and there was a greater decline from the 1st half CISP to the 2nd half CISP in PPO, MPO and WD at HYP. Heart rate was higher and peripheral arterial oxygen saturation lower during HYP compared to NORM (P<0.05). CONCLUSION Moderate hypoxia significantly reduced PPO (~4%), MPO (~5%) and WD (~5%) compared to normoxia. The results suggest athletes will be at a disadvantage when performing intermittent sprinting at moderate altitude.
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Affiliation(s)
- G Turner
- Exercise and Environmental Physiology School of Sport and Service Management University of Brighton, Eastbourne, UK -
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Gibson OR, Dennis A, Parfitt T, Taylor L, Watt PW, Maxwell NS. Extracellular Hsp72 concentration relates to a minimum endogenous criteria during acute exercise-heat exposure. Cell Stress Chaperones 2014; 19:389-400. [PMID: 24085588 PMCID: PMC3982022 DOI: 10.1007/s12192-013-0468-1] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Revised: 09/20/2013] [Accepted: 09/20/2013] [Indexed: 10/26/2022] Open
Abstract
Extracellular heat shock protein 72 (eHsp72) concentration increases during exercise-heat stress when conditions elicit physiological strain. Differences in severity of environmental and exercise stimuli have elicited varied response to stress. The present study aimed to quantify the extent of increased eHsp72 with increased exogenous heat stress, and determine related endogenous markers of strain in an exercise-heat model. Ten males cycled for 90 min at 50 % [Formula: see text] in three conditions (TEMP, 20 °C/63 % RH; HOT, 30.2 °C/51%RH; VHOT, 40.0 °C/37%RH). Plasma was analysed for eHsp72 pre, immediately post and 24-h post each trial utilising a commercially available ELISA. Increased eHsp72 concentration was observed post VHOT trial (+172.4 %) (p < 0.05), but not TEMP (-1.9 %) or HOT (+25.7 %) conditions. eHsp72 returned to baseline values within 24 h in all conditions. Changes were observed in rectal temperature (Trec), rate of Trec increase, area under the curve for Trec of 38.5 and 39.0 °C, duration Trec ≥38.5 and ≥39.0 °C, and change in muscle temperature, between VHOT, and TEMP and HOT, but not between TEMP and HOT. Each condition also elicited significantly increasing physiological strain, described by sweat rate, heart rate, physiological strain index, rating of perceived exertion and thermal sensation. Stepwise multiple regression reported rate of Trec increase and change in Trec to be predictors of increased eHsp72 concentration. Data suggests eHsp72 concentration increases once systemic temperature and sympathetic activity exceeds a minimum endogenous criteria elicited during VHOT conditions and is likely to be modulated by large, rapid changes in core temperature.
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Affiliation(s)
- Oliver R Gibson
- School of Sport and Service Management, Welkin Science Laboratories, University of Brighton, 30 Carlisle Road, Eastbourne, UK,
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