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Reynolds RJ, Shelhamer M, Antonsen EL, Carpentier WR. Characterizing dehydration in short-term spaceflight using evidence from Project Mercury. NPJ Microgravity 2024; 10:64. [PMID: 38862554 PMCID: PMC11166991 DOI: 10.1038/s41526-024-00374-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 03/04/2024] [Indexed: 06/13/2024] Open
Abstract
Short-term spaceflight is commonly perceived as posing minimal risk to human health and performance. However, despite their duration, short-term flights potentially induce acute physiological changes that create risk to crews. One such change is dehydration (primarily body water loss) due to a heat-stressed environment. Such loss, if severe and prolonged, can lead to decrements in performance as well as increase the risk of more serious medical conditions. Though the general mechanisms of dehydration are broadly understood, the rate and extent of dehydration in short-term spaceflight has not been characterized. Combining data from the six spaceflights of the US Mercury program with a causal diagram illustrating the mechanisms of dehydration, we fit a path model to estimate the causal effects for all pathways in the causal model. Results demonstrate that Mercury astronauts experienced some degree of dehydration across the range of suited time and that the relationship between suited time and dehydration appears to be logarithmic. We discuss causal interpretations of the results and how the results from this and similar analyses can inform countermeasure development for short-term spaceflight.
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Affiliation(s)
| | - Mark Shelhamer
- The Johns Hopkins University School of Medicine, Baltimore, MD, USA
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Yüksel S, Akıl M. Mild Dehydration Triggered by Exercise Reduces Cognitive Performance in Children, But Does Not Affect Their Motor Skills. JOURNAL OF THE AMERICAN NUTRITION ASSOCIATION 2024:1-9. [PMID: 38837125 DOI: 10.1080/27697061.2024.2362709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2024] [Accepted: 05/28/2024] [Indexed: 06/06/2024]
Abstract
OBJECTIVE Children face the risk of dehydration in varying amounts during the day due to reasons such as physical activity, sweating, eating salty foods and drinking carbonated beverages. It is assumed that dehydration can lead to impaired motor skills and cognitive performance since it affects brain function. However, inconsistencies in study results, test times and problems caused by heat stress make new research mandatory. In our research, we examined the effects of exercise-induced mild dehydration on motor skills and cognitive performance in active/sedentary boys who do/do not do regular physical activities in their daily lives. METHODS The study included 112 boys who do regular physical activity (n:57; 12.40 ± 0.49age) and sedentary (n:55; 12.49 ± 0.50age). The children were given a 12-h hydration program. Mild dehydration was created by giving exercises after hydration measurements. In case of hydration and mild dehydration, Bruininks-Oseretsky Motor Proficiency and d2 attention test were applied to the children. For comparison, Repeated Measures ANOVA and Bonferroni post-hoc test was performed at the second level. RESULTS According to the hydration and mild dehydration comparison results, there was no difference in total score of Fine Motor Skill Sensitivity, Fine Motor Skill Integration, Hand Dexterity and Bidirectional Coordination, Balance, Running Speed and Agility, Hand-Arm Coordination, Strength, and BOT-2 in children. There was a decrease in both groups in terms of Focused Attention, Processing Speed, Accuracy, Concentration Performance and Attention Span. CONCLUSION As a result, mild dehydration is associated with daily physical activity in children (physical education classes, etc.) or it can easily occur due to food/beverage preferences. It may affect children's performance of school curriculum and extracurricular activities. It shows that maintaining optimal hydration is important.
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Affiliation(s)
- Sinem Yüksel
- Graduate Education Institute, Uşak University, Uşak, Türkiye
| | - Mustafa Akıl
- Faculty of Sport Sciences, Uşak University, Uşak, Türkiye
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Xu Z, Yi W, Bach A, Tong S, Ebi KL, Su H, Cheng J, Rutherford S. Multimorbidity and emergency hospitalisations during hot weather. EBioMedicine 2024; 104:105148. [PMID: 38705102 PMCID: PMC11087953 DOI: 10.1016/j.ebiom.2024.105148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 04/18/2024] [Accepted: 04/21/2024] [Indexed: 05/07/2024] Open
Abstract
BACKGROUND People with chronic diseases are a commonly listed heat-vulnerable group in heat-health action plans. While prior research identifies multiple health conditions that may increase vulnerability to ambient heat, there is minimal evidence regarding the implications of multimorbidity (two or more chronic diseases). METHODS From the statewide hospital registry of Queensland, Australia, we identified people aged ≥15 years who had emergency hospitalisation(s) between March 2004 and April 2016 and previously had 0, 1, 2, or ≥3 of five chronic diseases: cardiovascular disease, diabetes, mental disorders, asthma/COPD, and chronic kidney disease. We conducted time-stratified case-crossover analyses to estimate the odds ratio of hospitalisations associated with ambient heat exposure in people with different numbers, types, and combinations of chronic diseases. Ambient heat exposure was defined as a 5 °C increase in daily mean temperature above the median. FINDINGS There were 2,263,427 emergency hospitalisations recorded (48.7% in males and 51.3% in females). When the mean temperature increased, hospitalisation odds increased with chronic disease number, particularly in older persons (≥65 years), males, and non-indigenous people. For instance, in older persons with 0, 1, 2, or ≥3 chronic diseases, the odds ratios associated with ambient heat exposure were 1.00 (95% confidence interval: 0.96, 1.04), 1.06 (1.02, 1.09), 1.08 (1.02, 1.14), and 1.13 (1.07, 1.19), respectively. Among the chronic diseases, chronic kidney disease, and asthma/COPD, either existing alone, together, or in combination with other diseases, were associated with the highest odds of hospitalisations under ambient heat exposure. INTERPRETATION While individuals with multimorbidity are considered in heat-health action plans, this study suggests the need to consider specifically examining them as a distinct and vulnerable subgroup. FUNDING Wellcome.
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Affiliation(s)
- Zhiwei Xu
- School of Medicine and Dentistry, Griffith University, Gold Coast, Australia; Cities Research Institute, Griffith University, Gold Coast, Australia.
| | - Weizhuo Yi
- School of Medicine and Dentistry, Griffith University, Gold Coast, Australia; School of Public Health, Anhui Medical University, Hefei, China
| | - Aaron Bach
- School of Medicine and Dentistry, Griffith University, Gold Coast, Australia; Cities Research Institute, Griffith University, Gold Coast, Australia
| | - Shilu Tong
- National Institute of Environmental Health, Chinese Center for Disease Control and Prevention, Beijing, China; School of Public Health and Social Work, Queensland University of Technology, Brisbane, Australia
| | - Kristie L Ebi
- Center for Health and the Global Environment, University of Washington, Seattle, USA
| | - Hong Su
- School of Public Health, Anhui Medical University, Hefei, China
| | - Jian Cheng
- School of Public Health, Anhui Medical University, Hefei, China
| | - Shannon Rutherford
- School of Medicine and Dentistry, Griffith University, Gold Coast, Australia; Cities Research Institute, Griffith University, Gold Coast, Australia
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McCubbin AJ, Irwin C. The effect of pre-exercise oral hyperhydration on endurance exercise performance, heart rate, and thermoregulation: a meta-analytical review. Appl Physiol Nutr Metab 2024; 49:569-583. [PMID: 38198662 DOI: 10.1139/apnm-2023-0384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2024]
Abstract
This study aimed to determine the effect of pre-exercise hyperhydration on endurance performance (primary outcome), heart rate, thermoregulation, and perceptual responses (secondary outcomes). Six academic databases were searched to February 2023. Only studies reporting differences in hydration between intervention and placebo/control were included. Meta-analysis determined overall effect size (Hedges' g), and meta-regression the influence of independent moderators (ambient temperature, hyperhydration agent, exercise mode, extent of hyperhydration). Overall, 10 publications generating 19 effect estimates for primary outcomes, and 11 publications reporting 48 effect estimates for secondary outcomes, were included. A small-to-moderate improvement in time-to-exhaustion (TTE) (Hedges' g = 0.31, 95% CI: 0.13-0.50, p = 0.001) and time trial (TT) (g = 0.25, 95% CI: 0.002-0.51, p = 0.049) but not total work (TW) tasks (p = 0.120) was found following hyperhydration. No moderating effects were observed. No effect of hyperhydration was found for heart rate following steady state (SS) exercise (p = 0.069) or the performance task (p = 0.072), nor for body temperature post-SS (p = 0.132) or post-performance task (p = 0.349), but meta-regression of sodium versus glycerol showed lower body temperature post-performance task with sodium (g = 0.80, t (5) = 2.65, p = 0.046). No effects were found for perceived exertion or thermal comfort. Study heterogeneity was low, lacking representation of elite and female athletes, and weight-bearing (i.e., running) exercise modalities. These results suggest pre-exercise hyperhydration provides a small-to-moderate benefit to endurance performance in TTE and TT, but not TW performance tasks. While no moderating effects were observed, lack of heterogeneity makes it difficult to generalise these findings.
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Affiliation(s)
- Alan J McCubbin
- Department of Nutrition, Dietetics and Food, Monash University, Notting Hill, Victoria, Australia
| | - Christopher Irwin
- School of Health Sciences and Social Work, Menzies Health Institute Queensland, Griffith University, Gold Coast, QLD, Australia
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Daci D, Altrichter S, Grillet FM, Dib S, Mouna A, Suresh Kumar S, Terhorst-Molawi D, Maurer M, Günzel D, Scheffel J. Altered Sweat Composition Due to Changes in Tight Junction Expression of Sweat Glands in Cholinergic Urticaria Patients. Int J Mol Sci 2024; 25:4658. [PMID: 38731882 PMCID: PMC11083780 DOI: 10.3390/ijms25094658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 04/15/2024] [Accepted: 04/20/2024] [Indexed: 05/13/2024] Open
Abstract
In cholinergic urticaria (CholU), small, itchy wheals are induced by exercise or passive warming and reduced sweating has been reported. Despite the described reduced muscarinic receptor expression, sweat duct obstruction, or sweat allergy, the underlying pathomechanisms are not well understood. To gain further insights, we collected skin biopsies before and after pulse-controlled ergometry and sweat after sauna provocation from CholU patients as well as healthy controls. CholU patients displayed partially severely reduced local sweating, yet total sweat volume was unaltered. However, sweat electrolyte composition was altered, with increased K+ concentration in CholU patients. Formalin-fixed, paraffin-embedded biopsies were stained to explore sweat leakage and tight junction protein expression. Dermcidin staining was not found outside the sweat glands. In the secretory coils of sweat glands, the distribution of claudin-3 and -10b as well as occludin was altered, but the zonula occludens-1 location was unchanged. In all, dermcidin and tight junction protein staining suggests an intact barrier with reduced sweat production capability in CholU patients. For future studies, an ex vivo skin model for quantification of sweat secretion was established, in which sweat secretion could be pharmacologically stimulated or blocked. This ex vivo model will be used to further investigate sweat gland function in CholU patients and decipher the underlying pathomechanism(s).
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Affiliation(s)
- Denisa Daci
- Clinical Physiology/Nutritional Medicine, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 12203 Berlin, Germany; (D.D.); (S.D.); (A.M.); (S.S.K.); (D.G.)
| | - Sabine Altrichter
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Allergology and Immunology, 12203 Berlin, Germany (D.T.-M.); (M.M.)
- Institute of Allergology, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 12203 Berlin, Germany
- Departement of Dermatology and Venerology, Kepler University Hospital, 4020 Linz, Austria
- Center for Medical Research, Johannes Kepler University, 4021 Linz, Austria
| | - François Marie Grillet
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Allergology and Immunology, 12203 Berlin, Germany (D.T.-M.); (M.M.)
- Institute of Allergology, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 12203 Berlin, Germany
| | - Selma Dib
- Clinical Physiology/Nutritional Medicine, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 12203 Berlin, Germany; (D.D.); (S.D.); (A.M.); (S.S.K.); (D.G.)
| | - Ahmad Mouna
- Clinical Physiology/Nutritional Medicine, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 12203 Berlin, Germany; (D.D.); (S.D.); (A.M.); (S.S.K.); (D.G.)
| | - Sukashree Suresh Kumar
- Clinical Physiology/Nutritional Medicine, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 12203 Berlin, Germany; (D.D.); (S.D.); (A.M.); (S.S.K.); (D.G.)
| | - Dorothea Terhorst-Molawi
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Allergology and Immunology, 12203 Berlin, Germany (D.T.-M.); (M.M.)
- Institute of Allergology, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 12203 Berlin, Germany
| | - Marcus Maurer
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Allergology and Immunology, 12203 Berlin, Germany (D.T.-M.); (M.M.)
- Institute of Allergology, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 12203 Berlin, Germany
| | - Dorothee Günzel
- Clinical Physiology/Nutritional Medicine, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 12203 Berlin, Germany; (D.D.); (S.D.); (A.M.); (S.S.K.); (D.G.)
| | - Jörg Scheffel
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Allergology and Immunology, 12203 Berlin, Germany (D.T.-M.); (M.M.)
- Institute of Allergology, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 12203 Berlin, Germany
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Doherty CS, Fortington LV, Barley OR. Sex Differences in Hydration Biomarkers and Test-Retest Reliability Following Passive Dehydration. Int J Sport Nutr Exerc Metab 2024; 34:88-100. [PMID: 38215737 DOI: 10.1123/ijsnem.2023-0146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 11/20/2023] [Accepted: 11/21/2023] [Indexed: 01/14/2024]
Abstract
This study investigated (a) differences between males and females for changes in serum, tear, and urine osmolality, hematocrit, and urine specific gravity following acute passive dehydration and (b) assessed the reliability of these biomarkers separately for each sex. Fifteen males (age: 26.3 ± 3.5 years, body mass: 76 ± 7 kg) and 15 females (age: 28.8 ± 6.4 years, body mass: 63 ± 7 kg) completed a sauna protocol twice (5-28 days apart), aiming for 4% body mass loss (BML). Urine, blood, and tear markers were collected pre- and postdehydration, and change scores were calculated. Male BML was significantly greater than that of females in Trial 1 (3.53% ± 0.55% vs. 2.53% ± 0.43%, p < .001) and Trial 2 (3.36% ± 0.66% vs. 2.53% ± 0.44%, p = .01). Despite significant differences in BML, change in hematocrit was the only change marker that displayed a significant difference in Trial 1 (males: 3% ± 1%, females: 2% ± 1%, p = .004) and Trial 2 (males: 3% ± 1%, females: 1% ± 1%, p = .008). Regression analysis showed a significant effect for sex (male) predicting change in hematocrit (β = 0.8, p = .032) and change in serum osmolality (β = -3.3, p = .005) when controlling for BML but not for urinary or tear measures. The intraclass correlation coefficients for females (ICC 2, 1) were highest for change in urine specific gravity (ICC = .62, p = .006) and lowest for change in tear osmolarity (ICC = -.14, p = .689), whereas for males, it was posthematocrit (ICC = .65, p = .003) and post tear osmolarity (ICC = .18, p = .256). Generally, biomarkers showed lower test-retest reliability in males compared with females but, overall, were classified as poor-moderate in both sexes. These findings suggest that the response and reliability of hydration biomarkers are sex specific and highlight the importance of accounting for BML differences.
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Affiliation(s)
- Colin S Doherty
- School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia
| | - Lauren V Fortington
- School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia
| | - Oliver R Barley
- School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia
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7
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Deshayes TA, Sodabi DGA, Dubord M, Gagnon D. Shifting focus: Time to look beyond the classic physiological adaptations associated with human heat acclimation. Exp Physiol 2024; 109:335-349. [PMID: 37885125 PMCID: PMC10988689 DOI: 10.1113/ep091207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2023] [Accepted: 10/12/2023] [Indexed: 10/28/2023]
Abstract
Planet Earth is warming at an unprecedented rate and our future is now assured to be shaped by the consequences of more frequent hot days and extreme heat. Humans will need to adapt both behaviorally and physiologically to thrive in a hotter climate. From a physiological perspective, countless studies have shown that human heat acclimation increases thermoeffector output (i.e., sweating and skin blood flow) and lowers cardiovascular strain (i.e., heart rate) during heat stress. However, the mechanisms mediating these adaptations remain understudied. Furthermore, several possible benefits of heat acclimation for other systems and functions involved in maintaining health and performance during heat stress remain to be elucidated. This review summarizes recent advances in human heat acclimation, with emphasis on recent studies that (1) advanced our understanding of the mechanisms mediating improved thermoeffector output and (2) investigated adaptations that go beyond those classically associated with heat acclimation. We highlight that these studies have contributed to a better understanding of the integrated physiological responses underlying human heat acclimation while leaving key unanswered questions that will need to be addressed in the future.
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Affiliation(s)
- Thomas A. Deshayes
- Montreal Heart InstituteMontréalCanada
- School of Kinesiology and Exercise ScienceUniversité de MontréalMontréalCanada
| | - Dèwanou Gilles Arnaud Sodabi
- Montreal Heart InstituteMontréalCanada
- School of Kinesiology and Exercise ScienceUniversité de MontréalMontréalCanada
| | - Marianne Dubord
- Montreal Heart InstituteMontréalCanada
- School of Kinesiology and Exercise ScienceUniversité de MontréalMontréalCanada
| | - Daniel Gagnon
- Montreal Heart InstituteMontréalCanada
- School of Kinesiology and Exercise ScienceUniversité de MontréalMontréalCanada
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8
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Rasmussen VF, Schmeichel A, Thrysøe M, Nyengaard JR, Christensen AMR, Vestergaard ET, Kristensen K, Terkelsen AJ, Karlsson P, Singer W. Sweat gland nerve fiber density and association with sudomotor function, symptoms, and risk factors in adolescents with type 1 diabetes. Clin Auton Res 2023; 33:691-703. [PMID: 37682387 PMCID: PMC10751258 DOI: 10.1007/s10286-023-00973-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 08/08/2023] [Indexed: 09/09/2023]
Abstract
PURPOSE To quantify sweat gland nerve fiber density in adolescents with diabetes. Additionally, to investigate associations between sudomotor innervation, sweat responses, and possible risk factors for sudomotor neuropathy. METHODS Cross-sectional study where 60 adolescents with type 1 diabetes (duration > 5 years) and 23 control subjects were included. Clinical data, quantitative sudomotor axon reflex test, and skin biopsies were obtained. Skin tissue was immunostained and imaged by confocal microscopy. Quantification of the sweat gland volume and three-dimensional reconstruction of the nerve fibers was performed using a design-unbiased technique. RESULTS Adolescents with diabetes had a significant reduction of maximum and mean values of nerve fiber length and nerve fiber density in sweat glands compared to controls (p values < 0.05). No association between nerve fiber density and sweat responses was found (p = 0.21). In cases with reduced sweat gland nerve fiber length, nerve fiber density, and volume, the sweat response was reduced or absent. Height, systolic blood pressure, time in hypoglycemia, and total daily and basal/total insulin dose were positively correlated to sweat response, while low-density lipoprotein, and HbA1c were negatively correlated with sweat response (p values < 0.05). Other microvascular complications and high cholesterol levels increased the relative risk for reduced sweat gland nerve fiber density. CONCLUSION Our findings of reduced sweat gland innervation in a selected group of adolescents add new knowledge about the structural changes that occur in autonomic nerves due to diabetes. Evaluating both the sweat gland innervation and sweat gland volume was important for understanding the association with sweat responses. Further research is needed to understand its clinical relevance.
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Affiliation(s)
- Vinni Faber Rasmussen
- Danish Pain Research Center, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.
- Department of Pediatrics and Adolescents, Randers Regional Hospital, Randers, Denmark.
- Steno Diabetes Center Aarhus, Aarhus University Hospital, Aarhus, Denmark.
| | - Ann Schmeichel
- Department of Neurology, Mayo Clinic, Rochester, MN, USA
| | - Mathilde Thrysøe
- Danish Pain Research Center, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Jens Randel Nyengaard
- Core Center for Molecular Morphology, Section for Stereology and Microscopy, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Pathology, Aarhus University Hospital, Aarhus, Denmark
| | - Ann-Margrethe Rønholt Christensen
- Steno Diabetes Center North Denmark, Aalborg, Denmark
- Department of Pediatrics and Adolescents, Aalborg University Hospital, Aalborg, Denmark
| | - Esben Thyssen Vestergaard
- Steno Diabetes Center Aarhus, Aarhus University Hospital, Aarhus, Denmark
- Department of Pediatrics and Adolescents, Aarhus University Hospital, Aarhus, Denmark
| | - Kurt Kristensen
- Steno Diabetes Center Aarhus, Aarhus University Hospital, Aarhus, Denmark
- Department of Pediatrics and Adolescents, Aarhus University Hospital, Aarhus, Denmark
| | - Astrid Juhl Terkelsen
- Danish Pain Research Center, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Neurology, Aarhus University Hospital, Aarhus, Denmark
| | - Páll Karlsson
- Danish Pain Research Center, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Steno Diabetes Center Aarhus, Aarhus University Hospital, Aarhus, Denmark
- Core Center for Molecular Morphology, Section for Stereology and Microscopy, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
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9
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Mayrovitz HN. Transepidermal water loss and stratum corneum hydration in forearm versus hand palm. Skin Res Technol 2023; 29:e13218. [PMID: 36973986 PMCID: PMC10155802 DOI: 10.1111/srt.13218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Accepted: 10/01/2022] [Indexed: 03/08/2023]
Abstract
BACKGROUND Skin measurements of transepidermal water loss (TEWL) and stratum corneum hydration (SCH) reflect different aspects of skin physiology. Since epidermal water loss depends on epidermal-to-air water vapor gradients, a possible quantitative relationship between TEWL and SCH may exist. This investigation's purpose was to test the possible TEWL-SCH relationship. MATERIALS AND METHODS SCH and TEWL were measured noninvasively on forearm and palmer thenar eminence (hand) in 40 young adults (20 males) along with total body fat percentage (FAT) via bioimpedance. RESULTS A significant positive nonlinear correlation (p < 0.001) was detected between SCH and TEWL in hands of the male cohort that occurred when SCH exceeded a threshold level. This threshold level was not exceeded in male or female forearms and forearms did not display a SCH-TEWL correlation. There was a weak inverse dependence of TEWL on FAT on both forearm and hand (p < 0.05), but no SCH-FAT relationship was observed. TEWL values on the forearm and hand were moderately correlated with each other (p = 0.002) but SCH values were not. CONCLUSION The findings clarify the relationship between forearm and palmer hydration and TEWL values, and their relationship to total body fat percentages in young healthy adults. The significant correlation between palmer stratum corneum hydration and palmer TEWL that was discovered in the male but not the female cohort suggests a threshold hydration level for which TEWL depends both on skin barrier function and stratum corneum hydration. This implies that conditions with increased SCH may in part account for elevated TEWL values.
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Affiliation(s)
- Harvey N. Mayrovitz
- Department of Medical EducationDr. Kiran C. Patel College of Allopathic MedicineNova Southeastern UniversityFloridaUSA
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10
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Moore SR, Gordon AN, Cabre HE, Hackney AC, Smith-Ryan AE. A Randomized Controlled Trial of Changes in Fluid Distribution across Menstrual Phases with Creatine Supplementation. Nutrients 2023; 15:nu15020429. [PMID: 36678300 PMCID: PMC9865497 DOI: 10.3390/nu15020429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 01/10/2023] [Accepted: 01/12/2023] [Indexed: 01/18/2023] Open
Abstract
This study examined the effects of creatine (Cr) loading on body mass (BM) and fluid markers of total body water (TBW), extra-cellular fluid (ECF), and intra-cellular fluid (ICF) across the menstrual cycle (MC). Thirty moderately active females, either naturally-menstruating (NM) or using hormonal contraceptives (HC), were randomized to Cr (Cr; 4 × 5 g/day of creatine monohydrate for 5 days; n = 15) or a non-caloric placebo (PL; n = 15) using a double-blind, placebo-controlled design, with a menstrual phase crossover. BM, TBW, ECF, and ICF were measured at pre- and post-supplementation in randomized order of follicular phase (FP; NM: MC days 0−8, HC: inactive pill days) or luteal phase (LP; NM: ≤15 days from next projected cycle start date, HC: active pill days) using bioelectrical impedance spectroscopy. Acute hydration status and salivary estrogen were used as covariates. Change in BM was not different between groups across MC ([PL-Cr] Δ 0.40 ± 0.50 kg; p = 0.427) or between MC phase across groups ([FP-LP] Δ 0.31 ± 0.48 kg; p = 0.528). TBW (p = 0.802), ECF (p = 0.373), and ICF (p = 0.795) were not different between supplement groups at pre-supplementation/FP time points. There were no significant differences between the NM and HC subjects at any time point, for any outcome (p > 0.05). Following LP supplementation, significant changes were observed in TBW (Cr: Δ 0.83 ± 0.38 L, PL: Δ −0.62 ± 0.38 L; p = 0.021), ECF (Cr: Δ 0.46 ± 0.15 L, PL: Δ −0.19 ± 0.15 L; p = 0.013), and ICF (Cr: Δ 0.74 ± 0.23 L, PL: Δ −0.02 ± 0.23 L; p = 0.041). These data demonstrate an increase in all fluid compartments in the LP following Cr loading, without observed alterations in body weight for females.
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Affiliation(s)
- Sam R. Moore
- Applied Physiology Laboratory, Department of Exercise and Sport Science, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Human Movement Science Curriculum, Department of Health Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Amanda N. Gordon
- Applied Physiology Laboratory, Department of Exercise and Sport Science, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Hannah E. Cabre
- Applied Physiology Laboratory, Department of Exercise and Sport Science, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Human Movement Science Curriculum, Department of Health Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Anthony C. Hackney
- Department of Nutrition, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Abbie E. Smith-Ryan
- Applied Physiology Laboratory, Department of Exercise and Sport Science, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Human Movement Science Curriculum, Department of Health Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Department of Nutrition, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Correspondence: ; Tel.: +1-919-962-2574
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11
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Trinschek J, Zieliński J, Zarębska EA, Kusy K. Male and female athletes matched for maximum oxygen uptake per skeletal muscle mass: equal but still different. J Sports Med Phys Fitness 2023; 63:95-103. [PMID: 35230070 DOI: 10.23736/s0022-4707.22.13605-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND We matched highly trained competitive male and female athletes using maximal oxygen uptake (V̇O<inf>2max</inf>) per kg skeletal muscle mass (SMM) to show sex differences in factors limiting V̇O<inf>2max</inf>. METHODS Thirteen highly trained male (28±3.0 yr) vs. 13 female (21.3±3.0 yr) endurance athletes and 10 male (23.9±3.8 yr) vs. 10 female sprinters (21.9±3.3 yr) performed an incremental running treadmill test until exhaustion. Main cardiorespiratory variables were measured using ergospirometry. SMM was determined using the dual X-ray absorptiometry method and a regression equation based on measured appendicular lean soft tissue. Basic hematological parameters were obtained from capillary blood samples taken before exercise. RESULTS In both endurance and sprint groups, male athletes had significantly higher muscle mass (by 8-12%) and substantially lower total fat (by 55-58%). For almost all body composition indicators, the effect size of sex differences was very large (Cohens d>1.4). Male athletes obtained significantly higher values in cardiorespiratory variables (by 12-34%) and factors related to oxygen transport (9-13%). Cohens d of the revealed differences was large or very large in both groups (0.8-2.1 in sprinters and 0.8-2.3 in endurance athletes). CONCLUSIONS Male and female competitive athletes having the same V̇̇O<inf>2max</inf> per kg SMM strongly differ in main factors limiting maximum oxygen uptake. These differences are more pronounced in endurance- than in sprint-trained athletes. The strongest differences are seen for body composition (fat, lean, and muscle mass) and central cardiac factors.
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Affiliation(s)
- Jacek Trinschek
- Department of Athletics, Strength and Conditioning, Faculty of Sport Sciences, Poznan University of Physical Education, Poznań, Poland -
| | - Jacek Zieliński
- Department of Athletics, Strength and Conditioning, Faculty of Sport Sciences, Poznan University of Physical Education, Poznań, Poland
| | - Ewa A Zarębska
- Department of Athletics, Strength and Conditioning, Faculty of Sport Sciences, Poznan University of Physical Education, Poznań, Poland
| | - Krzysztof Kusy
- Department of Athletics, Strength and Conditioning, Faculty of Sport Sciences, Poznan University of Physical Education, Poznań, Poland
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12
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Fernández-Peña C, Reimúndez A, Viana F, Arce VM, Señarís R. Sex differences in thermoregulation in mammals: Implications for energy homeostasis. Front Endocrinol (Lausanne) 2023; 14:1093376. [PMID: 36967809 PMCID: PMC10030879 DOI: 10.3389/fendo.2023.1093376] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 02/06/2023] [Indexed: 03/10/2023] Open
Abstract
Thermal homeostasis is a fundamental process in mammals, which allows the maintenance of a constant internal body temperature to ensure an efficient function of cells despite changes in ambient temperature. Increasing evidence has revealed the great impact of thermoregulation on energy homeostasis. Homeothermy requires a fine regulation of food intake, heat production, conservation and dissipation and energy expenditure. A great interest on this field of research has re-emerged following the discovery of thermogenic brown adipose tissue and browning of white fat in adult humans, with a potential clinical relevance on obesity and metabolic comorbidities. However, most of our knowledge comes from male animal models or men, which introduces unwanted biases on the findings. In this review, we discuss how differences in sex-dependent characteristics (anthropometry, body composition, hormonal regulation, and other sexual factors) influence numerous aspects of thermal regulation, which impact on energy homeostasis. Individuals of both sexes should be used in the experimental paradigms, considering the ovarian cycles and sexual hormonal regulation as influential factors in these studies. Only by collecting data in both sexes on molecular, functional, and clinical aspects, we will be able to establish in a rigorous way the real impact of thermoregulation on energy homeostasis, opening new avenues in the understanding and treatment of obesity and metabolic associated diseases.
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Affiliation(s)
| | - Alfonso Reimúndez
- Department of Physiology, CIMUS, University of Santiago de Compostela, Santiago de Compostela, Spain
| | - Félix Viana
- Institute of Neuroscience, University Miguel Hernández (UMH)-CSIC, Alicante, Spain
| | - Victor M. Arce
- Department of Physiology, CIMUS, University of Santiago de Compostela, Santiago de Compostela, Spain
- *Correspondence: Rosa Señarís, ; Victor M. Arce,
| | - Rosa Señarís
- Department of Physiology, CIMUS, University of Santiago de Compostela, Santiago de Compostela, Spain
- *Correspondence: Rosa Señarís, ; Victor M. Arce,
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13
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Burtscher J, Vanderriele PE, Legrand M, Predel HG, Niebauer J, O’Keefe JH, Millet GP, Burtscher M. Could Repeated Cardio-Renal Injury Trigger Late Cardiovascular Sequelae in Extreme Endurance Athletes? Sports Med 2022; 52:2821-2836. [DOI: 10.1007/s40279-022-01734-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/02/2022] [Indexed: 12/17/2022]
Abstract
AbstractRegular exercise confers multifaceted and well-established health benefits. Yet, transient and asymptomatic increases in markers of cardio-renal injury are commonly observed in ultra-endurance athletes during and after competition. This has raised concerns that chronic recurring insults could cause long-term cardiac and/or renal damage. Indeed, extreme endurance exercise (EEE) over decades has sometimes been linked with untoward cardiac effects, but a causal relation with acute injury markers has not yet been established. Here, we summarize the current knowledge on markers of cardiac and/or renal injury in EEE athletes, outline the possible interplay between cardiac and kidney damage, and explore the roles of various factors in the development of potential exercise-related cardiac damage, including underlying diseases, medication, sex, training, competition, regeneration, mitochondrial dysfunction, oxidative stress, and inflammation. In conclusion, despite the undisputed health benefits of regular exercise, we speculate, based on the intimate link between heart and kidney diseases, that in rare cases excessive endurance sport may induce adverse cardio-renal interactions that under specific, hitherto undefined conditions could result in persistent cardiac damage. We highlight future research priorities and provide decision support for athletes and clinical consultants who are seeking safe strategies for participation in EEE training and competition.
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14
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Smyth B, Maunder E, Meyler S, Hunter B, Muniz-Pumares D. Decoupling of Internal and External Workload During a Marathon: An Analysis of Durability in 82,303 Recreational Runners. Sports Med 2022; 52:2283-2295. [PMID: 35511416 PMCID: PMC9388405 DOI: 10.1007/s40279-022-01680-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/27/2022] [Indexed: 11/20/2022]
Abstract
Aim This study characterised the decoupling of internal-to-external workload in marathon running and investigated whether decoupling magnitude and onset could improve predictions of marathon performance. Methods The decoupling of internal-to-external workload was calculated in 82,303 marathon runners (13,125 female). Internal workload was determined as a percentage of maximum heart rate, and external workload as speed relative to estimated critical speed (CS). Decoupling magnitude (i.e., decoupling in the 35–40 km segment relative to the 5–10 km segment) was classified as low (< 1.1), moderate (≥ 1.1 but < 1.2) or high (≥ 1.2). Decoupling onset was calculated when decoupling exceeded 1.025. Results The overall internal-to-external workload decoupling experienced was 1.16 ± 0.22, first detected 25.2 ± 9.9 km into marathon running. The low decoupling group (34.5% of runners) completed the marathon at a faster relative speed (88 ± 6% CS), had better marathon performance (217.3 ± 33.1 min), and first experienced decoupling later in the marathon (33.4 ± 9.0 km) compared to those in the moderate (32.7% of runners, 86 ± 6% CS, 224.9 ± 31.7 min, and 22.6 ± 7.7 km), and high decoupling groups (32.8% runners, 82 ± 7% CS, 238.5 ± 30.7 min, and 19.1 ± 6.8 km; all p < 0.01). Compared to females, males’ decoupling magnitude was greater (1.17 ± 0.22 vs. 1.12 ± 0.16; p < 0.01) and occurred earlier (25.0 ± 9.8 vs. 26.3 ± 10.6 km; p < 0.01). Marathon performance was associated with the magnitude and onset of decoupling, and when included in marathon performance models utilising CS and the curvature constant, prediction error was reduced from 6.45 to 5.16%. Conclusion Durability characteristics, assessed as internal-to-external workload ratio, show considerable inter-individual variability, and both its magnitude and onset are associated with marathon performance.
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Affiliation(s)
- Barry Smyth
- Insight Centre for Data Analytics, School of Computer Science, University College Dublin, Dublin, Ireland.
| | - Ed Maunder
- Sports Performance Research Institute New Zealand, Auckland University Technology, Auckland, New Zealand
| | - Samuel Meyler
- School of Life and Medical Sciences, University of Hertfordshire, Hatfield, AL10 9AB, UK
| | - Ben Hunter
- School of Life and Medical Sciences, University of Hertfordshire, Hatfield, AL10 9AB, UK
| | - Daniel Muniz-Pumares
- School of Life and Medical Sciences, University of Hertfordshire, Hatfield, AL10 9AB, UK
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15
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Coudevylle GR, Collado A, Sinnapah S, Bouchard JP. Chaleur, sport et Santé. Partie 1 : Impact psychologique de la chaleur sur la santé des sportifs. ANNALES MEDICO-PSYCHOLOGIQUES 2022. [DOI: 10.1016/j.amp.2022.04.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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16
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Sex Differences in VO 2max and the Impact on Endurance-Exercise Performance. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19094946. [PMID: 35564339 PMCID: PMC9105160 DOI: 10.3390/ijerph19094946] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 04/15/2022] [Indexed: 02/04/2023]
Abstract
It was not until 1984 that women were permitted to compete in the Olympic marathon. Today, more women than men participate in road racing in all distances except the marathon where participation is near equal. From the period of 1985 to 2004, the women’s marathon record improved at a rate three times greater than men’s. This has led many to question whether women are capable of surpassing men despite the fact that there remains a 10–12% performance gap in all distance events. The progressive developments in sports performance research and training, beginning with A.V. Hill’s establishment of the concept of VO2max, have allowed endurance athletes to continue performance feats previously thought to be impossible. However, even today women are significantly underrepresented in sports performance research. By focusing more research on the female physiology and sex differences between men and women, we can better define how women differ from men in adapting to training and potentially use this information to improve endurance-exercise performance in women. The male advantage in endurance-exercise performance has commonly been attributed to their higher VO2max, even when expressed as mL/kg/min. It is widely known that oxygen delivery is the primary limiting factor in elite athletes when it comes to improving VO2max, but little research has explored the sex differences in oxygen delivery. Thus, the purpose of this review is to highlight what is known about the sex differences in the physiological factors contributing to VO2max, more specifically oxygen delivery, and the impacts on performance.
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17
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Ambient Temperature and Field-Based Cycling Performance: Insights From Male and Female Professional Cyclists. Int J Sports Physiol Perform 2022; 17:1025-1029. [PMID: 35338106 DOI: 10.1123/ijspp.2021-0508] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 01/24/2022] [Accepted: 01/24/2022] [Indexed: 11/18/2022]
Abstract
PURPOSE Ambient temperature affects endurance exercise performance. However, most research has been conducted in a laboratory-based setting, and whether there are sex-specific trends remains unclear. The present study aimed to analyze the influence of ambient temperature on cycling performance in male and female professional cyclists using field-based data collected during both training and racing. METHODS A total of 74 cyclists (48 male and 26 female; age 29 [5] y, 8 [5] y of experience in the professional category) were included in the analyses. We registered the participants' record power profile using data from both training and competitions over 8 years (2013-2020; 8 [5] seasons per cyclist). We analyzed their mean maximal power (MMP) values attained for efforts lasting 5 seconds, 30 seconds, 5 minutes, and 20 minutes at ambient temperatures ranging from <5°C to >35°C. RESULTS A significant influence of ambient temperature on MMP values was found in male and female cyclists (P < .001 for both), with no significant differences between sexes (P = .512). Cyclists attained the highest MMP values at temperate conditions (10-30°C in males and 5-25°C in females), whereas an impairment in performance was found at colder and hotter temperatures, particularly for the more extreme conditions (performance impairment at <5°C and >35°C of -18% to -9% and -16% to -9%, respectively). CONCLUSIONS Ambient temperature influences field-based cycling performance, following a reverse U-shaped relationship, with the highest MMP values attained in the range of ∼10°C to 25°C and with no major differences between sexes.
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18
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Notley SR, Akerman AP, Friesen BJ, Poirier MP, McCourt E, Flouris A, Kenny GP. Heat tolerance and the validity of occupational heat exposure limits in women during moderate-intensity work. Appl Physiol Nutr Metab 2022; 47:711-724. [PMID: 35259026 DOI: 10.1139/apnm-2022-0003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
To mitigate excessive rises in core temperature (>1°C) in non heat-acclimatized workers, the American Conference of Governmental Industrial Hygienists (ACGIH) provide heat stress limits (Action Limit Values; ALV), defined by the wet-bulb globe temperature (WBGT) and a worker's metabolic rate. However, since these limits are based on data from men, their suitability for women remains unclear. We therefore assessed core temperature and heart rate in men (n=19; body surface area-to-mass ratio: 250 (SD 17) cm2/kg) and women (n=15; body surface area-to-mass ratio: 268 (SD 24) cm2/kg) aged 18-45 years during 180-min walking at a moderate metabolic rate (200 W/m2) in WBGTs below (16 and 24°C) and above (28 and 32°C) ACGIH ALV. Sex did not significantly influence (i) rises in core temperature, irrespective of WBGT, (ii) the proportion of participants with rises in core temperature >1°C in environments below ACGIH limits, and (iii) work duration before rises in core temperature exceeded 1°C or volitional termination in environments above ACGIH limits. Although further studies are needed, these findings indicate that for the purpose of mitigating rises in core temperature exceeding recommended limits (>1°C), ACGIH guidelines have comparable effectiveness in non heat-acclimatized men and women when working at a moderate metabolic rate. Novelty points • Sex did not appreciably influence thermal strain nor the proportion of participants with core temperatures exceeding recommended limits. • Sex did not significantly influence tolerance to uncompensable heat stress • Despite originating from data obtained in only men, current occupational heat stress guidance offered comparable effectiveness in men and women.
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Affiliation(s)
| | | | - Brian J Friesen
- University of Ottawa, Human Kinetics, Ottawa, Ontario, Canada;
| | - Martin P Poirier
- University of Ottawa, School of Human Kinetics, Faculty of Health Sciences, Ottawa, Ontario, Canada;
| | | | - Andreas Flouris
- FAME Laboratory, Institute of Human Performance and Rehabilitation, Centre for Research and Technology Thessaly, Trikala, Thessaly, Greece.,Department of Research and Technology Development, Biomnic Ltd., Trikala, Thessaly, Greece;
| | - Glen P Kenny
- University of Ottawa, 6363, Ottawa, Canada, K1N 6N5.,Ottawa Hospital Research Institute, 10055, Ottawa, Canada, K1Y 4E9;
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19
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McCormick JJ, King KE, Rutherford MM, Meade RD, Notley SR, Akerman AP, Dokladny K, Kenny GP. Effect of extracellular hyperosmolality during normothermia and hyperthermia on the autophagic response in peripheral blood mononuclear cells from young men. J Appl Physiol (1985) 2022; 132:995-1004. [PMID: 35238651 DOI: 10.1152/japplphysiol.00661.2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Heat-stress induced dehydration is associated with extracellular hyperosmolality. To counteract the associated stress, cells employ cytoprotective mechanisms, including autophagy, however, the autophagic response to hyperosmotic stress has yet to be evaluated in humans. Thus, we investigated autophagy and associated cellular stress pathways (the heat shock response [HSR], apoptosis, and the acute inflammatory response) to isosmotic and hyperosmotic conditions with and without hyperthermia in twelve young men (mean [SD]; 25 [5] years). Participants received a 90-min intravenous infusion of either isosmotic (ISO; 0.9% NaCl; serum osmolality of 293 [4] mOsm/kg) or hyperosmotic (HYP; 3.0% NaCl; 300 [6] mOsm/kg) saline, followed by passive whole-body heating using a water perfused suit to increase esophageal temperature by ~0.8⁰C. Peripheral blood mononuclear cells were harvested at baseline (pre-infusion), post-infusion, and after heating, and changes in protein content were analyzed via Western blotting. Post-infusion, the LC3-II/I ratio was higher in HYP compared to ISO infusion (p<0.001), although no other protein changes were observed (all p>0.050). Following passive heating, autophagy increased in HYP, as demonstrated by an increase in LC3-II from baseline (p=0.004) and an elevated LC3-II/I ratio compared to ISO (p=0.035), and a decrease in p62 when compared to the ISO condition (p=0.019). This was accompanied by an elevation in cleaved caspase-3 following heating in the HYP condition (p<0.010), however, the HSR and acute inflammatory response did not change under any condition (all p>0.050). Taken together, our findings indicate that serum hyperosmolality induces autophagy and apoptotic signaling during mild hyperthermia with minimal autophagic activation during normothermia.
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Affiliation(s)
- James J McCormick
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Canada
| | - Kelli E King
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Canada
| | - Maura M Rutherford
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Canada
| | - Robert D Meade
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Canada.,Harvard T.H. Chan School of Public Health, Harvard University, Boston, MA, United States
| | - Sean R Notley
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Canada
| | - Ashley P Akerman
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Canada
| | - Karol Dokladny
- Department of Internal Medicine, University of New Mexico, Albuquerque, New Mexico, United States
| | - Glen P Kenny
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Canada.,Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, Ontario, Canada
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20
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Deshayes TA, Daigle N, Jeker D, Lamontagne-Lacasse M, Perreault-Briere M, Claveau P, Simoneau IL, Chamoux E, Goulet EDB. Impact of Repeated Acute Exposures to Low and Moderate Exercise-Induced Hypohydration on Physiological and Subjective Responses and Endurance Performance. Nutrients 2021; 13:nu13124477. [PMID: 34960028 PMCID: PMC8704556 DOI: 10.3390/nu13124477] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 11/18/2021] [Accepted: 11/23/2021] [Indexed: 11/16/2022] Open
Abstract
This study aimed to examine whether repeated exposures to low (2%) and moderate (4%) exercise-induced hypohydration may reverse the potentially deleterious effect of hypohydration on endurance performance. Using a randomized crossover protocol, ten volunteers (23 years, V˙O2max: 54 mL∙kg-1∙min-1) completed two 4-week training blocks interspersed by a 5-week washout period. During one block, participants replaced all fluid losses (EUH) while in the other they were fluid restricted (DEH). Participants completed three exercise sessions per week (walking/running, 55% V˙O2max, 40 °C): (1) 1 h while fluid restricted or drinking ad libitum, (2) until 2 and (3) 4% of body mass has been lost or replaced. During the first and the fourth week of each training block, participants completed a 12 min time-trial immediately after 2% and 4% body mass loss has been reached. Exercise duration and distance completed (14.1 ± 2.7 vs. 6.9 ± 1.5 km) during the fixed-intensity exercise bouts were greater in the 4 compared to the 2% condition (p < 0.01) with no difference between DEH and EUH. During the first week, heart rate, rectal temperature and perceived exertion were higher (p < 0.05) with DEH than EUH, and training did not change these outcomes. Exercise-induced hypohydration of 2% and 4% body mass impaired time-trial performance in a practical manner both at the start and end of the training block. In conclusion, exercise-induced hypohydration of 2% and 4% body mass impairs 12 min walking/running time-trial, and repeated exposures to these hypohydration levels cannot reverse the impairment in performance.
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Affiliation(s)
- Thomas A. Deshayes
- Faculty of Physical Activity Sciences, University of Sherbrooke, Sherbrooke, QC J1K 2R1, Canada; (T.A.D.); (N.D.); (D.J.); (M.L.-L.); (M.P.-B.); (P.C.)
- Research Center on Aging, University of Sherbrooke, Sherbrooke, QC J1H 4C4, Canada
| | - Nicolas Daigle
- Faculty of Physical Activity Sciences, University of Sherbrooke, Sherbrooke, QC J1K 2R1, Canada; (T.A.D.); (N.D.); (D.J.); (M.L.-L.); (M.P.-B.); (P.C.)
| | - David Jeker
- Faculty of Physical Activity Sciences, University of Sherbrooke, Sherbrooke, QC J1K 2R1, Canada; (T.A.D.); (N.D.); (D.J.); (M.L.-L.); (M.P.-B.); (P.C.)
| | - Martin Lamontagne-Lacasse
- Faculty of Physical Activity Sciences, University of Sherbrooke, Sherbrooke, QC J1K 2R1, Canada; (T.A.D.); (N.D.); (D.J.); (M.L.-L.); (M.P.-B.); (P.C.)
| | - Maxime Perreault-Briere
- Faculty of Physical Activity Sciences, University of Sherbrooke, Sherbrooke, QC J1K 2R1, Canada; (T.A.D.); (N.D.); (D.J.); (M.L.-L.); (M.P.-B.); (P.C.)
| | - Pascale Claveau
- Faculty of Physical Activity Sciences, University of Sherbrooke, Sherbrooke, QC J1K 2R1, Canada; (T.A.D.); (N.D.); (D.J.); (M.L.-L.); (M.P.-B.); (P.C.)
| | - Ivan L. Simoneau
- Centre de Recherche et de Formation par Simulation, Cegep of Sherbrooke, Sherbrooke, QC J1E 4K1, Canada;
| | - Estelle Chamoux
- Faculty of Arts and Science, Biological sciences, Bishop’s University, Sherbrooke, QC J1M 1Z7, Canada;
| | - Eric D. B. Goulet
- Faculty of Physical Activity Sciences, University of Sherbrooke, Sherbrooke, QC J1K 2R1, Canada; (T.A.D.); (N.D.); (D.J.); (M.L.-L.); (M.P.-B.); (P.C.)
- Research Center on Aging, University of Sherbrooke, Sherbrooke, QC J1H 4C4, Canada
- Correspondence:
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21
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Schlader ZJ, Schwob J, Hostler D, Cavuoto L. Simultaneous assessment of motor and cognitive tasks reveals reductions in working memory performance following exercise in the heat. Temperature (Austin) 2021; 9:344-356. [PMID: 36339090 PMCID: PMC9629122 DOI: 10.1080/23328940.2021.1992239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
This study tested the hypothesis that, following exercise in the heat, motor task performance will be impaired when assessed simultaneously with a cognitive task. In a randomized, crossover and counterbalanced design, twelve healthy adults (23 ± 2 years, 5 women) completed four 10-minute exercise circuits involving upper and lower body exercise in a moderate (18.1 ± 1.7°C, 38 ± 10% relative humidity) and a hot (40.3 ± 1.1°C, 26 ± 5% relative humidity) environment. Experimental testing was completed in a temperate thermal environment before exercise (~25°C) and in either the moderate or hot environment following exercise. The 3 Back test (a test of working memory) was used as the cognitive task and postural sway was used as the motor task. Cognitive and motor task performance assessments were conducted both individually (solo) and simultaneously (dual). At the end of exercise, core temperature (by 0.4 ± 0.3°C, P < 0.001), heart rate (by 12 ± 18 bpm, P = 0.025), and mean skin temperature (by 7.6 ± 0.8°C, P < 0.001) were higher in the Hot trial compared to Moderate. During solo testing, postural sway increased from pre- to post-exercise in the Hot (P ≤ 0.028), but not the Moderate (P ≥ 0.261) trial. During dual testing, postural sway did not differ between trials (P ≥ 0.065) or over time (P ≥ 0.094). During solo testing, 3 Back performance did not differ between trials (P = 0.810) or over time (P = 0.707), but during dual testing 3 Back performance following exercise was reduced in the Hot compared to the Moderate trial (P = 0.028). Simultaneous assessment of motor and cognitive tasks reveals that motor performance is reduced following exercise in the heat. .
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Affiliation(s)
- Zachary J. Schlader
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, USA,Department of Kinesiology, School of Public Health, Indiana University, Bloomington, USA
| | - Jacqueline Schwob
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, USA
| | - David Hostler
- Center for Research and Education in Special Environments, Department of Exercise and Nutrition Sciences, University at Buffalo, Buffalo, USA,Department of Emergency Medicine, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, USA
| | - Lora Cavuoto
- Department of Industrial and Systems Engineering, School of Engineering and Applied Sciences, University at Buffalo, Buffalo, USA,CONTACT Lora Cavuoto
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