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المؤلفون: JULIEN D. PÉRIARD, MATHEW G. WILSON, SAMUEL T. TEBECK, JAMES B. GILMORE, JAMIE STANLEY, OLIVIER GIRARD
المساهمون: Périard, Julien D, Wilson, Mathew G, Tebeck, Samuel T, Gilmore, James B, Stanley, Jamie, Girard, Olivier
المصدر: Medicine & Science in Sports & Exercise. 55:32-45
مصطلحات موضوعية: heat stress, Core temperature, perceived exertion, heart rate, Physical Therapy, Sports Therapy and Rehabilitation, Orthopedics and Sports Medicine, exertional heat illness
الوصف: Refereed/Peer-reviewed Purpose: This study aimed to characterize the thermal and cardiovascular strain of professional cyclists during the 2019 Tour Down Under and determine the associations between thermal indices and power output, and physiological strain. Methods: Gastrointestinal temperature (Tgi), heart rate (HR), and power output were recorded during the six stages (129–151.5 km) of the Tour Down Under in ≤22 male participants. Thermal indices included dry-bulb, black-globe, wet-bulb, and wet-bulb-globe (WBGT) temperature; relative humidity (RH), Heat Index; Humidex; and universal thermal climate index. The heat stress index (HSI), which reflects human heat strain, was also calculated. Results: Dry-bulb temperature was 23°C–37°C, and RH was 18%–72% (WBGT: 21°C–29°C). Mean Tgi was 38.2°C–38.5°C, and mean peak Tgi was 38.9°C–39.4°C, both highest values recorded during stage 3 (WBGT: 27°C). Peak individual Tgi was ≥40.0°C in three stages and ≥39.5°C in 14%–33% of cyclists in five stages. Mean HR was 131–147 bpm (68%–77% of peak), with the highest mean recorded in stage 3 (P ≤ 0.005). Mean power output was 180–249 W, with the highest mean recorded during stage 4 (P < 0.001; 21°C WBGT). The thermal indices most strongly correlated with power output were black-globe temperature (r = −0.778), RH (r = 0.768), universal thermal climate index (r = −0.762), and WBGT (r = −0.745; all P < 0.001). Mean Tgi was correlated with wet-bulb temperature (r = 0.495), HSI (r = 0.464), and Humidex (r = 0.314; all P < 0.05), whereas mean HR was most strongly correlated with HSI (r = 0.720), along with Tgi (r = 0.599) and power output (r = 0.539; all P < 0.05). Conclusions: Peak Tgi reached 40.0°C in some cyclists, although most remained
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::848a58e9a713667c8912bf3294560664
https://doi.org/10.1249/mss.0000000000003028 -
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المؤلفون: Thomas H. Topham, James W. Smallcombe, Brad Clark, Harry A. Brown, Richard D. Telford, Ollie Jay, Julien D. Périard
المصدر: American Journal of Physiology-Regulatory, Integrative and Comparative Physiology. 323:R161-R168
مصطلحات موضوعية: Adult, Male, Hot Temperature, Physiology, Physiology (medical), Humans, Female, Sweating, Heat Stress Disorders, Heat-Shock Response, Body Temperature, Body Temperature Regulation
الوصف: Both adult females and children have been reported to have a lower sweating capacity and thus reduced evaporative heat loss potential that may increase their susceptibility to exertional hyperthermia in the heat. Compared with males, females have a lower maximal sweat rate and thus a theoretically lower maximum skin wettedness due to a lower sweat output per gland. Similarly, children have been suggested to be disadvantaged in high ambient temperatures due to a lower sweat production and therefore reduced evaporative capacity, despite modifications of heat transfer due to physical attributes and possible evaporative efficiency. The reported reductions in the sudomotor activity of females and children suggest a lower sweating capacity in girls. However, because of the complexities of isolating sex and maturation from the confounding effects of morphological differences (e.g., body surface area-to-mass ratio) and metabolic heat production, limited evidence exists supporting whether children, and, more specifically, girls are at a thermoregulatory disadvantage. Furthermore, a limited number of child-adult comparison studies involve females and very few studies have directly compared regional and whole body sudomotor activity between boys and girls. This minireview highlights the exercise-induced sudomotor response of females and children, summarizes previous research investigating the sudomotor response to exercise in girls, and suggests important areas for further research.
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::24972131bb2ddd115fc088244418566d
https://doi.org/10.1152/ajpregu.00328.2021 -
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المؤلفون: Felicity M. Bright, Brad Clark, Ollie Jay, Julien D. Périard
المصدر: Medicine & Science in Sports & Exercise.
مصطلحات موضوعية: Physical Therapy, Sports Therapy and Rehabilitation, Orthopedics and Sports Medicine
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_________::3a50a518afffe466136bd4ef7cdf71ce
https://doi.org/10.1249/mss.0000000000003168 -
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المؤلفون: Sara A. Guevara, Melissa L. Crunkhorn, Michael Drew, Gordon Waddington, Julien D. Périard, Naroa Etxebarria, Liam A. Toohey, Paula Charlton
المصدر: Journal of Sport and Health Science.
مصطلحات موضوعية: Physical Therapy, Sports Therapy and Rehabilitation, Orthopedics and Sports Medicine
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المؤلفون: Harry A. Brown, Thomas H. Topham, Brad Clark, James W. Smallcombe, Andreas D. Flouris, Leonidas G. Ioannou, Richard D. Telford, Ollie Jay, Julien D. Périard
المصدر: Sports Medicine. 52:2111-2128
مصطلحات موضوعية: Physical Therapy, Sports Therapy and Rehabilitation, Orthopedics and Sports Medicine
الوصف: Background Physiological heat adaptations can be induced following various protocols that use either artificially controlled (i.e. acclimation) or naturally occurring (i.e. acclimatisation) environments. During the summer months in seasonal climates, adequate exposure to outdoor environmental heat stress should lead to transient seasonal heat acclimatisation. Objectives The aim of the systematic review was to assess the available literature and characterise seasonal heat acclimatisation during the summer months and identify key factors that influence the magnitude of adaptation. Eligibility Criteria English language, full-text articles that assessed seasonal heat acclimatisation on the same sample of healthy adults a minimum of 3 months apart were included. Data Sources Studies were identified using first- and second-order search terms in the databases MEDLINE, SPORTDiscus, CINAHL Plus with Full Text, Scopus and Cochrane, with the last search taking place on 15 July 2021. Risk of Bias Studies were independently assessed by two authors for the risk of bias using a modified version of the McMaster critical review form. Data Extraction Data for the following outcome variables were extracted: participant age, sex, body mass, height, body fat percentage, maximal oxygen uptake, time spent exercising outdoors (i.e. intensity, duration, environmental conditions), heat response test (i.e. protocol, time between tests), core temperature, skin temperature, heart rate, whole-body sweat loss, whole-body and local sweat rate, sweat sodium concentration, skin blood flow and plasma volume changes. Results Twenty-nine studies were included in this systematic review, including 561 participants across eight countries with a mean summer daytime wet-bulb globe temperature (WBGT) of 24.9 °C (range: 19.5–29.8 °C). Two studies reported a reduction in resting core temperature (0.16 °C; p −1; p −1; p p Limitations The available studies primarily focussed on healthy male adults and demonstrated large differences in the reporting of factors that influence the development of seasonal heat acclimatisation, namely, exposure time and duration, exercise task and environmental conditions. Conclusions Seasonal heat acclimatisation is induced across various climates in healthy adults. The magnitude of adaptation is dependent on a combination of environmental and physical activity characteristics. Providing environmental conditions are conducive to adaptation, the duration and intensity of outdoor physical activity, along with the timing of exposures, can influence seasonal heat acclimatisation. Future research should ensure the documentation of these factors to allow for a better characterisation of seasonal heat acclimatisation. PROSPERO Registration CRD42020201883.
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المؤلفون: Andrew J. McKune, Alice Wallett, Julien D. Périard, Philo U. Saunders
المصدر: International Journal of Sport Nutrition and Exercise Metabolism. 31:359-368
مصطلحات موضوعية: Hot Temperature, Strenuous exercise, Physical Exertion, Population, Medicine (miscellaneous), Physiology, Fatty Acid-Binding Proteins, Gastrointestinal epithelium, 03 medical and health sciences, Oxygen Consumption, 0302 clinical medicine, Humans, Medicine, Orthopedics and Sports Medicine, Intestinal Mucosa, education, Exercise, education.field_of_study, Membrane Glycoproteins, Nutrition and Dietetics, biology, business.industry, 030229 sport sciences, General Medicine, Endotoxins, Gastrointestinal Tract, Critical appraisal, Systematic review, Athletes, Intestinal Fatty Acid-Binding Protein, biology.protein, Carrier Proteins, Digestion, business, Lipopolysaccharide binding protein, Biomarkers, 030217 neurology & neurosurgery, Acute-Phase Proteins
الوصف: Along with digestion and absorption of nutrients, the gastrointestinal epithelium acts as a primary intestinal defense layer, preventing luminal pathogens from entering the circulation. During exercise in the heat, epithelial integrity can become compromised, allowing bacteria and bacterial endotoxins to translocate into circulation, triggering a systemic inflammatory response and exacerbating gastrointestinal damage. While this relationship seems clear in the general population in endurance/ultraendurance exercise, the aim of this systematic review was to evaluate the effect of exercise in the heat on blood markers of gastrointestinal epithelial disturbance in well-trained individuals. Following the 2009 Preferred Reporting Items for Systematic Reviewed and Meta-Analyses guidelines, five electronic databases were searched for appropriate research, and 1,885 studies were identified. Five studies met the inclusion criteria and were subject to full methodological appraisal by two reviewers. Critical appraisal of the studies was conducted using the McMasters Critical Review Form. The studies investigated changes in markers of gastrointestinal damage (intestinal fatty acid–binding protein, endotoxin, and/or lipopolysaccharide-binding protein) following acute exercise in warm to hot conditions (≥ 30 °C) and included trained or well-trained participants with direct comparisons to a control temperate condition (≤ 22 °C). The studies found that prolonged submaximal and strenuous exercise in hot environmental conditions can acutely increase epithelial disturbance compared with exercise in cooler conditions, with disturbances not being clinically relevant. However, trained and well-trained populations appear to tolerate exercise-induced gastrointestinal disturbance in the heat. Whether this is an acquired tolerance related to regular training remains to be investigated.
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::e570aa6c7274dcc42208e6911f1f5605
https://doi.org/10.1123/ijsnem.2021-0040 -
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المؤلفون: Thijs M. H. Eijsvogels, Julien D. Périard, Hein A.M. Daanen
المساهمون: Physiology, AMS - Sports
المصدر: Physiological Reviews, 101, 4, pp. 1873-1979
Périard, J D, Eijsvogels, T M H & Daanen, H A M 2021, ' Exercise under heat stress : thermoregulation, hydration, performance implications, and mitigation strategies ', Physiological reviews, vol. 101, no. 4, pp. 1873-1979 . https://doi.org/10.1152/physrev.00038.2020
Physiological reviews, 101(4), 1873-1979. American Physiological Society
Physiological Reviews, 101, 1873-1979مصطلحات موضوعية: Hyperthermia, medicine.medical_specialty, Hot Temperature, cooling, Physiology, Acclimatization, Body water, Vascular damage Radboud Institute for Health Sciences [Radboudumc 16], Thermal strain, Sweating, Heat Stress Disorders, 03 medical and health sciences, 0302 clinical medicine, Heat illness, Physical medicine and rehabilitation, Heat acclimation, Physiology (medical), Exercise performance, medicine, Animals, Humans, Molecular Biology, Exercise, business.industry, Water, 030229 sport sciences, General Medicine, Thermoregulation, medicine.disease, Water Loss, Insensible, fluid balance, Heat stress, exercise capacity, fatigue, heat acclimation, business, SDG 6 - Clean Water and Sanitation, 030217 neurology & neurosurgery, Heat-Shock Response, Psychomotor Performance, Body Temperature Regulation
الوصف: Contains fulltext : 238775.pdf (Publisher’s version ) (Open Access) A rise in body core temperature and loss of body water via sweating are natural consequences of prolonged exercise in the heat. This review provides a comprehensive and integrative overview of how the human body responds to exercise under heat stress and the countermeasures that can be adopted to enhance aerobic performance under such environmental conditions. The fundamental concepts and physiological processes associated with thermoregulation and fluid balance are initially described, followed by a summary of methods to determine thermal strain and hydration status. An outline is provided on how exercise-heat stress disrupts these homeostatic processes, leading to hyperthermia, hypohydration, sodium disturbances, and in some cases exertional heat illness. The impact of heat stress on human performance is also examined, including the underlying physiological mechanisms that mediate the impairment of exercise performance. Similarly, the influence of hydration status on performance in the heat and how systemic and peripheral hemodynamic adjustments contribute to fatigue development is elucidated. This review also discusses strategies to mitigate the effects of hyperthermia and hypohydration on exercise performance in the heat by examining the benefits of heat acclimation, cooling strategies, and hyperhydration. Finally, contemporary controversies are summarized and future research directions are provided.
وصف الملف: application/pdf
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ef4417a74a9b4a2e2c8da93774c1c394
https://hdl.handle.net/2066/238775 -
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المؤلفون: Anthony Shaw, Nathan R Riding, Julien D. Périard, David Nichols, Gavin Travers, José González-Alonso
المصدر: American Journal of Physiology-Heart and Circulatory Physiology. 319:H965-H979
مصطلحات موضوعية: Adult, Male, Thermotolerance, Cardiac function curve, Heat Stress, medicine.medical_specialty, Coronavirus disease 2019 (COVID-19), Physiology, Cardiac Volume, Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), 030204 cardiovascular system & hematology, Ventricular Function, Left, Body Temperature, Ventricular filling, 03 medical and health sciences, 0302 clinical medicine, Heat acclimation, Heart Rate, Physiology (medical), Internal medicine, medicine, Humans, Exercise, Blood Volume, Dehydration, business.industry, Body Weight, Hypohydration, Stroke Volume, Stroke volume, Heat stress, Systemic hemodynamics, Cardiology, Cardiology and Cardiovascular Medicine, business, human activities, 030217 neurology & neurosurgery
الوصف: This study demonstrates that 10 days of exercise heat acclimation has minimal effects on left ventricular volumes, intrinsic cardiac function, and systemic hemodynamics during prolonged, repeated semirecumbent exercise in moderate heat, where heart rate and blood volume are similar to preacclimation levels. However, progressive dehydration is consistently associated with similar degrees of hyperthermia and tachycardia and reductions in blood volume, diastolic filling of the left ventricle, stroke volume, and cardiac output, regardless of acclimation state.
URL الوصول: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::fc7791d5dce081c00ced825ee1814d4f
https://doi.org/10.1152/ajpheart.00466.2020 -
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المؤلفون: Andreas D. Flouris, Lars Nybo, Styliani Ziaka, Sebastien Racinais, Julien D. Périard, Zoe Panagiotaki, Konstantinos Mantzios, Leonidas G. Ioannou
المصدر: Mantzios, K, Ioannou, L G, Panagiotaki, Z, Ziaka, S, Périard, J D, Racinais, S, Nybo, L & Flouris, A D 2022, ' Effects of weather parameters on endurance running performance: Discipline-specific analysis of 1258 races ', Medicine and Science in Sports and Exercise, vol. 54, no. 1, pp. 153-161 . https://doi.org/10.1249/MSS.0000000000002769
Medicine and Science in Sports and Exerciseمصطلحات موضوعية: Marathon, Race, Meteorology, Wet-bulb globe temperature, COMPETITION, Physical Therapy, Sports Therapy and Rehabilitation, HEAT, Athletic Performance, Wind speed, Running, Degree (temperature), Extreme heat, MARATHON, Faculty of Science, Humans, Orthopedics and Sports Medicine, COLD, Weather, RACE, Competition, Applied Sciences, Humidity, OLYMPICS, Heat, Weather parameter, Air temperature, ComputingMethodologies_DOCUMENTANDTEXTPROCESSING, Environmental science, High heat, Endurance running, Olympics, Cold
الوصف: Supplemental digital content is available in the text.
Introduction This study evaluated how single or combinations of weather parameters (temperature, humidity, wind speed, and solar load) affect peak performance during endurance running events and identified which events are most vulnerable to varying weather conditions. Methods Results for the marathon, 50-km racewalking, 20-km racewalking, and 10,000-, 5000-, and 3000-m steeplechase were obtained from the official Web sites of large competitions. We identified meteorological data from nearby (8.9 ± 9.3 km) weather stations for 1258 races held between 1936 and 2019 across 42 countries, enabling analysis of 7867 athletes. Results The wet bulb globe temperature (WBGT) across races ranged from −7°C to 33°C, with 27% of races taking place in cold/cool, 47% in neutral, 18% in moderate heat, 7% in high heat, and 1% in extreme heat conditions, according to the World Athletics classification. Machine learning decision trees (R2 = 0.21–0.58) showed that air temperature (importance score = 40%) was the most important weather parameter. However, when used alone, air temperature had lower predictive power (R2 = 0.04–0.34) than WBGT (R2 = 0.11–0.47). Conditions of 7.5°C–15°C WBGT (or 10°C–17.5°C air temperature) increased the likelihood for peak performance. For every degree WBGT outside these optimum conditions, performance declined by 0.3%–0.4%. Conclusion More than one-quarter of endurance running events were held in moderate, high, or extreme heat, and this number reached one-half when marathons were excluded. All four weather parameters should be evaluated when aiming to mitigate the health and performance implications of exercising at high intensities in a hot environment with athletes adopting heat mitigation strategies when possible.وصف الملف: application/pdf
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https://curis.ku.dk/portal/da/publications/effects-of-weather-parameters-on-endurance-running-performance-disciplinespecific-analysis-of-1258-races(9b19f5b6-01e1-4843-9cc0-2f7c5aa6b6fa).html -
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المؤلفون: Avish P. Sharma, David Ritchie, Julien D. Périard, Philip Young-Ill Choi, Benjamin G. Serpell, Stephen Freeman
المصدر: Journal of Science and Medicine in Sport. 23:75-81
مصطلحات موضوعية: Adult, Male, Iron Overload, Blood transfusion, medicine.medical_treatment, Football, Physiology, Physical Therapy, Sports Therapy and Rehabilitation, Blood volume, Single-Case Studies as Topic, Hemoglobins, 03 medical and health sciences, 0302 clinical medicine, Altitude, Reticulocyte Count, Altitude training, Humans, Medicine, Blood Transfusion, Orthopedics and Sports Medicine, Longitudinal Studies, 030212 general & internal medicine, Hemochromatosis, Leukemia, business.industry, Repeated measures design, 030229 sport sciences, medicine.disease, Athletes, Ferritins, Hemoglobin, business, Physical Conditioning, Human, Blood drawing
الوصف: Objectives To examine iron stores, hemoglobin mass, and performance before, during and after intermittent altitude exposure in a professional male rugby player experiencing iron overload following blood transfusions for treatment for acute myeloid leukemia. Design Longitudinal, repeated measures, single case-study. Methods The player was followed prior to (control), and during (study), an in-season block of altitude training. During the control period two venesections were performed for a total of 750 mL of blood removal. Internal and external training load, match statistics, blood volume, plasma volume, haemoglobin mass, serum ferritin and reticulocyte count were monitored throughout. Results During the control period serum ferritin declined following the two venesections (∼51%) as did haemoglobin mass (∼2%), reticulocyte count remained stable. During the study period serum ferritin further declined (∼30%), however haemoglobin mass and reticulocyte count increased (∼4% and ∼14% respectively). Internal training load for the control and study period was similar, however external training load was lower in the study period. Match statistics were not favourable for the player during the control period, however they improved during the study period. Conclusions This case supports the theory that individuals with elevated iron availability are well placed to achieve increases in haemoglobin mass. Furthermore, although therapeutic venesections may still be required to manage iron overload, the addition of altitude exposure may be a method to assist in reducing total body iron by means of mobilising available (excessive) iron to incorporate into haemoglobin. Altitude exposure did not hinder the players’ performance. Further research is encouraged.
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