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Notley SR, Mitchell D, Taylor NAS. A century of exercise physiology: concepts that ignited the study of human thermoregulation. Part 3: Heat and cold tolerance during exercise. Eur J Appl Physiol 2024; 124:1-145. [PMID: 37796292 DOI: 10.1007/s00421-023-05276-3] [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: 01/26/2023] [Accepted: 07/04/2023] [Indexed: 10/06/2023]
Abstract
In this third installment of our four-part historical series, we evaluate contributions that shaped our understanding of heat and cold stress during occupational and athletic pursuits. Our first topic concerns how we tolerate, and sometimes fail to tolerate, exercise-heat stress. By 1900, physical activity with clothing- and climate-induced evaporative impediments led to an extraordinarily high incidence of heat stroke within the military. Fortunately, deep-body temperatures > 40 °C were not always fatal. Thirty years later, water immersion and patient treatments mimicking sweat evaporation were found to be effective, with the adage of cool first, transport later being adopted. We gradually acquired an understanding of thermoeffector function during heat storage, and learned about challenges to other regulatory mechanisms. In our second topic, we explore cold tolerance and intolerance. By the 1930s, hypothermia was known to reduce cutaneous circulation, particularly at the extremities, conserving body heat. Cold-induced vasodilatation hindered heat conservation, but it was protective. Increased metabolic heat production followed, driven by shivering and non-shivering thermogenesis, even during exercise and work. Physical endurance and shivering could both be compromised by hypoglycaemia. Later, treatments for hypothermia and cold injuries were refined, and the thermal after-drop was explained. In our final topic, we critique the numerous indices developed in attempts to numerically rate hot and cold stresses. The criteria for an effective thermal stress index were established by the 1930s. However, few indices satisfied those requirements, either then or now, and the surviving indices, including the unvalidated Wet-Bulb Globe-Thermometer index, do not fully predict thermal strain.
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Affiliation(s)
- Sean R Notley
- Defence Science and Technology Group, Department of Defence, Melbourne, Australia
- School of Human Kinetics, University of Ottawa, Ottawa, Canada
| | - Duncan Mitchell
- Brain Function Research Group, School of Physiology, University of the Witwatersrand, Johannesburg, South Africa
- School of Human Sciences, University of Western Australia, Crawley, Australia
| | - Nigel A S Taylor
- Research Institute of Human Ecology, College of Human Ecology, Seoul National University, Seoul, Republic of Korea.
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Charkoudian N, Lee JKW, Giersch GEW, DiPietro L, Stachenfeld N. Different perspectives on women's health, nutrition and endurance exercise. J Int Soc Sports Nutr 2023; 20:2286286. [PMID: 38018805 PMCID: PMC11018311 DOI: 10.1080/15502783.2023.2286286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 11/16/2023] [Indexed: 11/30/2023] Open
Affiliation(s)
- Nisha Charkoudian
- US Army Research Institute of Environmental Medicine, Thermal & Mountain Medicine Division, Natick, MA, USA
| | - Jason K W Lee
- National University of Singapore, Heat Resilience and Performance Centre, Yong Loo Lin School of Medicine, Singapore, Singapore
| | - Gabrielle E W Giersch
- US Army Research Institute of Environmental Medicine, Thermal & Mountain Medicine Division, Natick, MA, USA
| | - Loretta DiPietro
- The George Washington University, Department of Exercise and Nutrition Sciences, Milken Institute School of Public Health, Washington, USA
| | - Nina Stachenfeld
- Yale School of Medicine, John B. Pierce Laboratory, Obstetrics Gynecology and Reproductive Sciences, New Haven, CT, USA
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Norton KM, Davies RS, LeCheminant JD, Fullmer S. Educational Preparation and Course Approach of Undergraduate Sports Nutrition instructors in Large U.S. Institutions. Sports (Basel) 2023; 11:176. [PMID: 37755853 PMCID: PMC10536551 DOI: 10.3390/sports11090176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 08/30/2023] [Accepted: 09/01/2023] [Indexed: 09/28/2023] Open
Abstract
College courses are often offered from various disciplines, and depending on which department offers the class, the course could be taught by faculty with different educational preparation or training. This could result in significant differences in the approach and content of the course (i.e., theoretical or applied) or a difference in the instructors' perceived importance and, therefore, the depth and time spent on various topics. We evaluated potential differences in the sports nutrition curriculum because it is a course that is usually taught by either nutritionists or exercise physiologists. A cross-sectional survey was sent to sports nutrition instructors at accredited large U.S. institutions. Descriptive statistics were analyzed via an ANOVA and Χ2 using Crosstabs in Qualtrics. Alpha was set at p < 0.001. Additionally, short interviews with some participants were recorded and transcribed verbatim. The findings of this study indicated that regardless of the instructor's educational preparation and discipline, the majority of sports nutrition topics received similar time and depth and were rated as similarly important (p > 0.001). Out of 10 current textbooks, the majority of instructors preferred only 1 of 4 of them. From the short interviews, instructors reported that their courses were more applied than theoretical or balanced between the two. Most instructors designed their courses with a focus on achieving applied outcomes.
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Affiliation(s)
- Kayla Marie Norton
- Department of Nutrition, Dietetics and Food Science, Brigham Young University, Provo, UT 84602, USA
| | - Randall Spencer Davies
- Department of Instructional Psychology and Technology, Brigham Young University, Provo, UT 84602, USA
| | - James Derek LeCheminant
- Department of Nutrition, Dietetics and Food Science, Brigham Young University, Provo, UT 84602, USA
| | - Susan Fullmer
- Department of Nutrition, Dietetics and Food Science, Brigham Young University, Provo, UT 84602, USA
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Johnson KB, Connolly CP, Cho SP, Miller TK, Sallis RE, Hiller WDB. Clinical presentation of exercise-associated hyponatremia in male and female IRONMAN® triathletes over three decades. Scand J Med Sci Sports 2023; 33:1841-1849. [PMID: 37204065 DOI: 10.1111/sms.14401] [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: 01/17/2023] [Revised: 04/16/2023] [Accepted: 05/09/2023] [Indexed: 05/20/2023]
Abstract
PURPOSE Exercise-associated hyponatremia (EAH) is common in ultra-endurance events and severe cases are more common in females. The purpose of this paper is to compare the clinical presentation of EAH between male and female triathletes in ultra-endurance competitions. METHODS Medical records with sodium concentrations (n = 3138) from the IRONMAN® World Championships over the timeframe of 1989-2019 were reviewed for both male (n = 2253) and female (n = 885) competitors. Logistic regression was used to explore the relationships between sex, sodium concentration, and various clinical presentations. RESULTS When comparing male and female triathletes, clinical variables found to have a different relationship with sodium concentration include altered mental status (inversely related in males and not related in females), abdominal pain, muscle cramps, hypotension, and tachycardia (directly related in males and not related in females), and vomiting and hypokalemia (not related in males and inversely related in females). Overall, males lost significantly more weight than females, and notably, approximately half of all athletes were dehydrated and lost weight. CONCLUSIONS Altered mental status, vomiting, abdominal pain, muscle cramps, hypotension, tachycardia, and hyperkalemia appear to present differently between sexes when comparing hyponatremic to eunatremic athletes. Although overhydration is the most common etiology of hypervolemic hyponatremia, hypovolemic hyponatremia comprises a significant amount of hyponatremic triathletes. Further understanding of how EAH presents helps athletes and medical professionals identify it early and prevent life-threatening complications.
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Affiliation(s)
- Kasey B Johnson
- Elson S. Floyd College of Medicine, Washington State University, Spokane, WA, USA
| | | | - Stephanie P Cho
- College of Education, Washington State University, Pullman, WA, USA
| | - Thomas K Miller
- Virginia Tech Carilion School of Medicine, Roanoke, Virginia, USA
| | - Robert E Sallis
- UC Riverside School of Medicine, Riverside, California, USA
- Kaiser Permanente, Sports Medicine, Fontana, California, USA
| | - W Douglas B Hiller
- Elson S. Floyd College of Medicine, Washington State University, Spokane, WA, USA
- John A. Burns College of Medicine at University of Hawai'i, Honolulu, Hawaii, USA
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Effects of Sodium Intake on Health and Performance in Endurance and Ultra-Endurance Sports. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19063651. [PMID: 35329337 PMCID: PMC8955583 DOI: 10.3390/ijerph19063651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 03/03/2022] [Accepted: 03/08/2022] [Indexed: 11/17/2022]
Abstract
The majority of reviews on sports nutrition issues focus on macronutrients, often omitting or paying less attention to substances such as sodium. Through the literature, it is clear that there are no reviews that focus entirely on the effects of sodium and in particular on endurance sports. Sodium intake, both at high and low doses, has been found to be associated with health and performance issues in athletes. Besides, there have been theories that an electrolyte imbalance, specifically sodium, contributes to the development of muscle cramps (EAMC) and hyponatremia (EAH). For this reason, it is necessary to create this systematic review, in order to report extensively on the role of sodium consumption in the population and more specifically in endurance and ultra-endurance athletes, the relationship between the amount consumed and the occurrence of pathological disorders, the usefulness of simultaneous hydration and whether a disturbance of this substance leads to EAH and EAMC. As a method of data collection, this study focused on exploring literature from 2000–2021. The search was conducted through the research engines PubMed and Scopus. In order to reduce the health and performance effects in endurance athletes, simultaneous emphasis should be placed on both sodium and fluid intake.
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López de Lara D, Ruiz-Sánchez JG, Cuesta M, Seara G, Calle-Pascual AL, Rubio Herrera MÁ, Runkle I, Verbalis JG. Exercise-Induced Hyponatremia: An Assessment of the International Hydration Recommendations Followed During the Gran Trail De Peñalara and Vitoria-Gasteiz Ironman Competitions. Front Nutr 2022; 8:781229. [PMID: 35265650 PMCID: PMC8898836 DOI: 10.3389/fnut.2021.781229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 12/06/2021] [Indexed: 11/13/2022] Open
Abstract
Introduction Hyponatremia often occurs during the practice of endurance sports. We evaluated the impact on hyponatremia of the hydration recommendations of the Third International Exercise-Associated Hyponatremia Consensus Development Conference 2015 (3IE-AHCD) during the 2017 Gran Trail de Peñalara marathon (GTP) and the Vitoria Gasteiz Ironman triathlon (VGI). Methods Prospective study of GTP and VGI athletes participating in four information sessions in the months prior to the events, to explain that hydration should only be according to their level of thirst, per the recommendations of the 3IE-AHCD. Consenting event finishers were included in final analysis. Pre- and post-race anthropometric and biochemical parameters were compared. Results Thirty-six GTP (33 male) and 94 VGI (88 male) finishers were evaluated. GTP race median fluid intake was 800 ml/h, with 900 ml/h in the VGI race. 83.3% GTPfin and 77.6% VGIfin remained eunatremic (blood sodium 135–145 mmol/L). Only 1/36 GTP and 1/94 VGI participant finished in hyponatremia, both with a sodium level of 134 mmol/L. Fourteen percent of GTP, and 21.2% of VGI participants finished in hypernatremia, with no increase in race completion times. No participating athlete required medical attention, except for musculoskeletal complaints. Pro-BNP and Copeptin levels rose significantly. Changes in copeptin levels did not correlate with changes in plasma osmolality, nor total body water content in impedance analysis. Conclusions Recommending that athletes' fluid intake in endurance events be a function of their thirst almost entirely prevented development of hyponatremia, without induction of clinically significant hypernatremia, or a negative repercussion on race completion times.
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Affiliation(s)
- Diego López de Lara
- Endocrinología Pediátrica, Hospital Clínico San Carlos, Instituto de Investigación Sanitaria Biomédica San Carlos (IdISSC), Madrid, Spain
| | - Jorge Gabriel Ruiz-Sánchez
- Endocrinología y Nutrición, Hospital Universitario Fundación Jiménez Díaz, Instituto de Investigación Sanitaria Biomédica San Carlos (IdISSC), Madrid, Spain
| | - Martín Cuesta
- Endocrinología y Nutrición, Hospital Universitario Fundación Jiménez Díaz, Instituto de Investigación Sanitaria Biomédica San Carlos (IdISSC), Madrid, Spain
| | - Germán Seara
- Hospital Clínico San Carlos, Instituto de Investigación Sanitaria Biomédica San Carlos (IdISSC), Madrid, Spain
| | - Alfonso Luis Calle-Pascual
- Endocrinología y Nutrición, Hospital Universitario Fundación Jiménez Díaz, Instituto de Investigación Sanitaria Biomédica San Carlos (IdISSC), Madrid, Spain
| | - Miguel Ángel Rubio Herrera
- Endocrinología y Nutrición, Hospital Universitario Fundación Jiménez Díaz, Instituto de Investigación Sanitaria Biomédica San Carlos (IdISSC), Madrid, Spain
| | - Isabelle Runkle
- Endocrinología y Nutrición, Hospital Universitario Fundación Jiménez Díaz, Instituto de Investigación Sanitaria Biomédica San Carlos (IdISSC), Madrid, Spain
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Seal AD, Kavouras SA. A review of risk factors and prevention strategies for exercise associated hyponatremia. Auton Neurosci 2022; 238:102930. [PMID: 35016044 DOI: 10.1016/j.autneu.2021.102930] [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: 05/21/2021] [Revised: 10/29/2021] [Accepted: 12/08/2021] [Indexed: 10/19/2022]
Abstract
Exercise-associated hyponatremia (EAH) is defined as a serum sodium concentration under 135 mmol·L-1 during or within 24 h of exercise. Increasing interest in endurance events has led to a higher number of athletes presenting with this potentially life-threatening condition. EAH is largely caused by the overconsumption of hypotonic fluids leading to weight gain during exercise. The primary risk factors include the inappropriate secretion of arginine vasopressin, longer exercise duration, smaller body mass, and to smaller extent ingestion of non-steroidal anti-inflammatory drugs. Accurate tracking of fluid intake and losses to prevent weight gain during exercise, sodium supplementation, and heat acclimatization may help attenuate declines in serum sodium concentration during exercise.
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Affiliation(s)
- Adam D Seal
- Center for Health Research, Kinesiology and Public Health, California Polytechnic State University, San Luis Obispo, CA, USA
| | - Stavros A Kavouras
- Hydration Science Lab, College of Health Solutions, Arizona State University, Phoenix, AZ, USA.
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Giersch GEW, Charkoudian N, McClung HL. The Rise of the Female Warfighter: Physiology, Performance, and Future Directions. Med Sci Sports Exerc 2021; 54:683-691. [PMID: 34939610 DOI: 10.1249/mss.0000000000002840] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
ABSTRACT Since 1948, the United States military has been open to both men and women as permanent party service members. However, in the majority of the time since, there have been a subset of military occupational specialties (MOS), or job descriptions, open only to men. In particular, jobs requiring more intense physical and/or environmental strain were considered to be beyond the physiological capabilities of women. In the present analysis, we review the literature regarding neuromuscular, physical performance, and environmental physiology in women, to highlight that women have no inherent limitation in their capacity to participate in relevant roles and jobs within the military, within accepted guidelines to promote risk mitigation across sexes. First, we discuss performance and injury risk: both neuromuscular function and physical capabilities. Second, physiological responses to environmental stress. Third, we discuss risk as it relates to reproductive health and nutritional considerations. We conclude with a summary of current physiological, performance and injury risk data in men and women that support our overarching purpose, as well as suggestions for future directions.
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Affiliation(s)
- Gabrielle E W Giersch
- Thermal and Mountain Medicine Division, United States Army Research Institute of Environmental Medicine, Natick, MA Biophysical and Biomedical Modeling Division, United States Army Research Institute of Environmental Medicine, Natick, MA Oak Ridge Institute for Science and Technology, Oak Ridge, TN
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Rangan GK, Dorani N, Zhang MM, Abu-Zarour L, Lau HC, Munt A, Chandra AN, Saravanabavan S, Rangan A, Zhang JQJ, Howell M, Wong AT. Clinical characteristics and outcomes of hyponatraemia associated with oral water intake in adults: a systematic review. BMJ Open 2021; 11:e046539. [PMID: 34887267 PMCID: PMC8663108 DOI: 10.1136/bmjopen-2020-046539] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 11/10/2021] [Indexed: 12/29/2022] Open
Abstract
INTRODUCTION Excessive water intake is rarely associated with life-threatening hyponatraemia. The aim of this study was to determine the clinical characteristics and outcomes of hyponatraemia associated with excess water intake. METHODS This review was conducted using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. All studies (case reports, observational or interventional studies) reporting excess water intake and hyponatraemia in adults (1946-2019) were included. RESULTS A total of 2970 articles were identified and 177 were included (88.7% case reports), consisting of 590 patients. The mean age was 46±16 years (95% CI 44 to 48 years), 47% female, 52% had a chronic psychiatric disorder and 31% had no underlying condition. The median volume of water consumed and serum sodium at presentation was 8 L/day (95% CI 8.9 to 12.2 L/day) and 118 mmol/L (95% CI 116 to 118 mmol/L), respectively. The motivator for increased water consumption was psychogenic polydipsia (55%); iatrogenic (13%); exercise (12%); habitual/dipsogenic polydipsia (7%) and other reasons (13%). The clinical features on presentation were severe in 53% (seizures, coma); moderate in 35% (confusion, vomiting, agitation) and mild in 5% (dizziness, lethargy, cognitive deficit) and not reported in 5% of studies. Treatment was supportive in 41% of studies (fluid restriction, treatment of the underlying cause, emergency care), and isotonic and hypertonic saline was used in 18% and 28% of cases, respectively. Treatment-related complications included osmotic demyelination (3%) and rhabdomyolysis (7%), and death occurred in 13% of cases. CONCLUSION Water intoxication is associated with significant morbidity and mortality and requires daily intake to substantially exceed population-based recommendations. The limitations of this analysis are the low quality and high risk of bias of the included studies. PROSPERO REGISTRATION NUMBER A pre-existing protocol in the international prospective register of systematic reviews was updated to incorporate any new amendments and reregistered at http://www.crd.york.ac.uk/PROSPERO (registration no. CRD42019129809).
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Affiliation(s)
- Gopala K Rangan
- Michael Stern Laboratory for Polycystic Kidney Disease, Westmead Institute for Medical Research, Westmead, New South Wales, Australia
- Department of Renal Medicine, Westmead Hospital, Westmead, New South Wales, Australia
| | - Nilofar Dorani
- Michael Stern Laboratory for Polycystic Kidney Disease, Westmead Institute for Medical Research, Westmead, New South Wales, Australia
- School of Life and Environmental Sciences, The University of Sydney, Camperdown, New South Wales, Australia
| | - Miranda M Zhang
- Michael Stern Laboratory for Polycystic Kidney Disease, Westmead Institute for Medical Research, Westmead, New South Wales, Australia
- School of Life and Environmental Sciences, The University of Sydney, Camperdown, New South Wales, Australia
| | - Lara Abu-Zarour
- Michael Stern Laboratory for Polycystic Kidney Disease, Westmead Institute for Medical Research, Westmead, New South Wales, Australia
- School of Life and Environmental Sciences, The University of Sydney, Camperdown, New South Wales, Australia
| | - Ho Ching Lau
- Michael Stern Laboratory for Polycystic Kidney Disease, Westmead Institute for Medical Research, Westmead, New South Wales, Australia
- School of Life and Environmental Sciences, The University of Sydney, Camperdown, New South Wales, Australia
| | - Alexandra Munt
- Michael Stern Laboratory for Polycystic Kidney Disease, Westmead Institute for Medical Research, Westmead, New South Wales, Australia
- Department of Renal Medicine, Westmead Hospital, Westmead, New South Wales, Australia
| | - Ashley N Chandra
- Michael Stern Laboratory for Polycystic Kidney Disease, Westmead Institute for Medical Research, Westmead, New South Wales, Australia
- Department of Renal Medicine, Westmead Hospital, Westmead, New South Wales, Australia
| | - Sayanthooran Saravanabavan
- Michael Stern Laboratory for Polycystic Kidney Disease, Westmead Institute for Medical Research, Westmead, New South Wales, Australia
| | - Anna Rangan
- Nutrition and Dietetics, Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
| | - Jennifer Q J Zhang
- Michael Stern Laboratory for Polycystic Kidney Disease, Westmead Institute for Medical Research, Westmead, New South Wales, Australia
- Department of Renal Medicine, Westmead Hospital, Westmead, New South Wales, Australia
| | - Martin Howell
- School of Public Health, The University of Sydney, Sydney, New South Wales, Australia
| | - Annette Ty Wong
- Michael Stern Laboratory for Polycystic Kidney Disease, Westmead Institute for Medical Research, Westmead, New South Wales, Australia
- Department of Renal Medicine, Westmead Hospital, Westmead, New South Wales, Australia
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Khodaee M, Saeedi A, Harris-Spinks C, Hew-Butler T. Incidence of exercise-associated hyponatremia during a high-altitude 161-km ultramarathon. Phys Act Nutr 2021; 25:16-22. [PMID: 34727684 PMCID: PMC8580585 DOI: 10.20463/pan.2021.0016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Accepted: 09/06/2021] [Indexed: 11/22/2022] Open
Abstract
[Purpose] Exercise-associated hyponatremia (EAH) is a well-known condition among endurance athletes at low altitudes. The incidence of EAH during ultramarathons at high altitudes warrants further investigation. This prospective observational study was conducted on the participants of the Leadville Trail 100 run, a 161-km race held at a high altitude (2,800 m-3,840 m). [Methods] Venous blood samples were collected before and immediately after the race. The participants completed an electronic survey after the race. Our main outcome measure was the post-race serum sodium ([Na+]) level. [Results] Of the 672 athletes who started the race, 351 (52%) successfully completed the event within the 30-hour cut-off. Post-race blood samples were collected from 84 runners (66 finishers). Both pre- and post-race blood samples were collected from 37 participants. Twenty percent of the post-race participants had EAH. Only one post-race participant had a [Na+] level of <130 mmol/L. All participants with EAH were asymptomatic. One participant had an abnormal pre-race [Na+] level (134 mmol/L). Female participants had a significantly higher rate of EAH than male participants (40% vs. 16%; p=0.039). Age, body mass index, weight changes, race completion status, nonsteroidal anti-inflammatory drug use, and urine specific gravity were not associated with the development of EAH. Lower postrace [Na+] levels were associated with higher serum creatine kinase values (R2=0.1, p<0.005). [Conclusion] High altitude (3,840 m peak) does not appear to enhance the incidence of EAH after an ultramarathon footrace. This suggests that ambient temperature (low temperatures reduce risk), sex (female predilection), endurance running, and overhydration are more prominent risk factors for EAH than high altitude.
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Affiliation(s)
- Morteza Khodaee
- University of Colorado School of Medicine, Department of Family Medicine and Orthopedics, Denver, USA
| | - Anahita Saeedi
- University of Massachusetts, Department of Biostatistics, MA, USA
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Lipman GS, Burns P, Phillips C, Jensen J, Little C, Jurkiewicz C, Jarrett B, Walker A, Mansfield N, Krabak BJ. Effect of Sodium Supplements and Climate on Dysnatremia During Ultramarathon Running. Clin J Sport Med 2021; 31:e327-e334. [PMID: 32097177 DOI: 10.1097/jsm.0000000000000832] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 01/19/2020] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Analyze the effect of sodium supplementation, hydration, and climate on dysnatremia in ultramarathon runners. DESIGN Prospective observational study. SETTING The 2017 80 km (50 mile) stage of the 250 km (150 mile) 6-stage RacingThePlanet ultramarathon in 2017 Chilean, Patagonian, and 2018 Namibian, Mongolian, and Chilean deserts. PARTICIPANTS All race entrants who could understand English were invited to participate, with 266 runners enrolled, mean age of 43 years (± 9), 61 (36%) females, average weight 74 kg (± 12.5), and average race time 14.5 (± 4.1) hours. Post-race sodium collected on 174 (74%) and 164 (62%) participants with both the blood sample and post-race questionnaire. INTERVENTION Weight change and finish line serum sodium levels were gathered. MAIN OUTCOME MEASURES Incidence of exercise-associated hyponatremia (EAH; <135 mmol·L-1) and hypernatremia (>145 mmol·L-1) by sodium ingestion and climate. RESULTS Eleven (6.3%) runners developed EAH, and 30 (17.2%) developed hypernatremia. Those with EAH were 14 kg heavier at baseline, had significantly less training distances, and averaged 5 to 6 hours longer to cover 50 miles (80 km) than the other participants. Neither rate nor total ingested supplemental sodium was correlated with dysnatremia, without significant differences in drinking behaviors or type of supplement compared with normonatremic runners. Hypernatremic runners were more often dehydrated [8 (28%), -4.7 kg (± 9.8)] than EAH [4 (14%), -1.1 kg (± 3.8)] (P < 0.01), and EAH runners were more frequently overhydrated (6, 67%) than hypernatremia (1, 11%) (P < 0.01). In the 98 (56%) runners from hot races, there was EAH OR = 3.5 [95% confidence interval (CI), 0.9-25.9] and hypernatremia OR = 8.8 (95% CI, 2.9-39.5) compared with cold races. CONCLUSIONS This was the first study to show that hot race climates are an independent risk factor for EAH and hypernatremia. Sodium supplementation did not prevent EAH nor cause hypernatremia. Longer training distances, lower body mass, and avoidance of overhydration were shown to be the most important factors to prevent EAH and avoidance of dehydration to prevent hypernatremia.
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Affiliation(s)
- Grant S Lipman
- Department of Emergency Medicine, Stanford University School of Medicine, Palo Alto, California
| | - Patrick Burns
- Department of Emergency Medicine, Stanford University School of Medicine, Palo Alto, California
| | - Caleb Phillips
- Department of Computational Science, University of Colorado, Boulder, Colorado
| | - Jacob Jensen
- Department of Emergency Medicine, University of New Mexico, Albuquerque, New Mexico
| | - Colin Little
- Department of Emergency Medicine, Oregon Health and Sciences University, Portland, Oregon
| | - Carrie Jurkiewicz
- Department of Emergency Medicine, Stanford University School of Medicine, Palo Alto, California
| | - Bryan Jarrett
- Department of Emergency Medicine, Massachusetts General Hospital, Boston, Massachusetts; and
| | - Anne Walker
- Department of Emergency Medicine, Stanford University School of Medicine, Palo Alto, California
| | - Nicky Mansfield
- Department of Emergency Medicine, University of New Mexico, Albuquerque, New Mexico
| | - Brian J Krabak
- Department of Orthopedics and Sports Medicine, University of Washington, Seattle, Washington
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Armstrong LE. Rehydration during Endurance Exercise: Challenges, Research, Options, Methods. Nutrients 2021; 13:887. [PMID: 33803421 PMCID: PMC8001428 DOI: 10.3390/nu13030887] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 02/27/2021] [Accepted: 03/01/2021] [Indexed: 01/18/2023] Open
Abstract
During endurance exercise, two problems arise from disturbed fluid-electrolyte balance: dehydration and overhydration. The former involves water and sodium losses in sweat and urine that are incompletely replaced, whereas the latter involves excessive consumption and retention of dilute fluids. When experienced at low levels, both dehydration and overhydration have minor or no performance effects and symptoms of illness, but when experienced at moderate-to-severe levels they degrade exercise performance and/or may lead to hydration-related illnesses including hyponatremia (low serum sodium concentration). Therefore, the present review article presents (a) relevant research observations and consensus statements of professional organizations, (b) 5 rehydration methods in which pre-race planning ranges from no advanced action to determination of sweat rate during a field simulation, and (c) 9 rehydration recommendations that are relevant to endurance activities. With this information, each athlete can select the rehydration method that best allows her/him to achieve a hydration middle ground between dehydration and overhydration, to optimize physical performance, and reduce the risk of illness.
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Affiliation(s)
- Lawrence E Armstrong
- Human Performance Laboratory and Korey Stringer Institute, University of Connecticut, Storrs, CT 06269-1110, USA
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13
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Lipman GS, Hew-Butler T, Phillips C, Krabak B, Burns P. Prospective Observational Study of Weight-based Assessment of Sodium Supplements on Ultramarathon Performance (WASSUP). SPORTS MEDICINE - OPEN 2021; 7:13. [PMID: 33594588 PMCID: PMC7886928 DOI: 10.1186/s40798-021-00302-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 01/24/2021] [Indexed: 02/05/2023]
Abstract
BACKGROUND Sodium supplements are ubiquitous in endurance running, but their impact on performance has been subjected to much debate. The objective of the study was to assess the effect of sodium supplementation as a weight-based predictor of race performance in ultramarathon runners. METHODS Prospective observational study during an 80 km (50 mi) stage of a 6-stage 250 km (155 mi) ultramarathon in Chile, Patagonia, Namibia, and Mongolia. Finish line hydration status as measured by weight change, point-of-care serum sodium, and questionnaire provided sodium ingestion categories at 33rd percentile and 66th percentile both for weight-adjusted rate and total sodium consumption, then analyzed for significant relationships to race performance, dysnatremia, and hydration. RESULTS Two hundred sixty-six participants were enrolled, with 217 (82%) with complete sodium supplement rate data, 174 (80%) with finish line sodium, and 161 (74%) with both pre-race weights and total sodium ingestion allowing weight-based analysis. Sodium intake ranged from 131-533 mg/h/kg (2-7.2 gm), with no statistically significant impact on pace, race time, or quintile rank. These outcomes did not change when sodium intake was analyzed as a continuous variable or by sub-group analysis of the 109 (68%) normonatremic runners. When controlled for weight-adjusted sodium intake, performance was poorly correlated with hydration (r = - 0.152, 95% CI - 0.348-0.057). Dehydrated runners outperformed those overhydrated, with 11% of top 25th percentile finishers dehydrated (versus 2.8% overhydrated), with 3.6 min/km faster pace and time 4.6 h faster finishing time. CONCLUSIONS No association was found between sodium supplement intake and ultramarathon performance. Dehydrated runners were found to have the best performance. This reinforces the message to avoid overhydration.
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Affiliation(s)
- Grant S Lipman
- Department of Emergency Medicine, Stanford University School of Medicine, 900 Welch Rd, Suite #350, Palo Alto, CA, 94304, USA.
| | - Tamara Hew-Butler
- Exercise and Sport Science, College of Education, Wayne State University, Detroit, MI, USA
| | - Caleb Phillips
- Computational Science, University of Colorado, Boulder, CO, USA
| | - Brian Krabak
- Department of Orthopedics and Sports Medicine, University of Washington, Seattle, WA, USA
| | - Patrick Burns
- Department of Emergency Medicine, Stanford University School of Medicine, 900 Welch Rd, Suite #350, Palo Alto, CA, 94304, USA
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Bennett BL, Hew-Butler T, Rosner MH, Myers T, Lipman GS. Wilderness Medical Society Clinical Practice Guidelines for the Management of Exercise-Associated Hyponatremia: 2019 Update. Wilderness Environ Med 2020; 31:50-62. [PMID: 32044213 DOI: 10.1016/j.wem.2019.11.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 11/07/2019] [Accepted: 11/13/2019] [Indexed: 11/25/2022]
Abstract
Exercise-associated hyponatremia (EAH) is defined by a serum or plasma sodium concentration below the normal reference range of 135 mmol·L-1 that occurs during or up to 24 h after prolonged physical activity. It is reported to occur in individual physical activities or during organized endurance events conducted in environments in which medical care is limited and often not available, and patient evacuation to definitive care is often greatly delayed. Rapid recognition and appropriate treatment are essential in the severe form to increase the likelihood of a positive outcome. To mitigate the risk of EAH mismanagement, care providers in the prehospital and in hospital settings must differentiate from other causes that present with similar signs and symptoms. EAH most commonly has overlapping signs and symptoms with heat exhaustion and exertional heat stroke. Failure in this regard is a recognized cause of worsened morbidity and mortality. In an effort to produce best practice guidelines for EAH management, the Wilderness Medical Society convened an expert panel in May 2018. The panel was charged with updating the WMS Practice Guidelines for Treatment of Exercise-Associated Hyponatremia published in 2014 using evidence-based guidelines for the prevention, recognition, and treatment of EAH. Recommendations are made based on presenting with symptomatic EAH, particularly when point-of-care blood sodium testing is unavailable in the field. These recommendations are graded on the basis of the quality of supporting evidence and balanced between the benefits and risks/burdens for each parameter according to the methodology stipulated by the American College of Chest Physicians.
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Affiliation(s)
- Brad L Bennett
- Military & Emergency Medicine Department, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD.
| | - Tamara Hew-Butler
- Division of Kinesiology, Health and Sport Studies, Wayne State University, Detroit, MI
| | - Mitchell H Rosner
- Division of Nephrology, University of Virginia Health System, Charlottesville, VA
| | - Thomas Myers
- Grand Canyon National Park, Branch of Emergency Services, Grand Canyon, AZ
| | - Grant S Lipman
- Department of Emergency Medicine, Stanford University School of Medicine, Stanford, CA
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15
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Graham SM, Martindale RJJ, McKinley M, Connaboy C, Andronikos G, Susmarski A. The examination of mental toughness, sleep, mood and injury rates in an Arctic ultra-marathon. Eur J Sport Sci 2020; 21:100-106. [PMID: 32089095 DOI: 10.1080/17461391.2020.1733670] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
There is scarcity of research examining the physiological and psychological effects of ultra-endurance racing on athletes in extreme conditions. The purpose of the current study was to identify common injury patterns and illness, profile mood states and sleep patterns and finally examine the relationships between mental toughness, sleep, mood and injury rates during a 120 mile, three-day Arctic ultra-marathon. Twelve participants (3 females, 9 males) with a mean age of 42 ± 5.35 yrs participated in the study. Mental toughness was measured using the MT18 questionnaire. Injuries were clinically assessed and recorded each day. Temperatures ranged from -20 to -6 degrees Celsius throughout the race. Sleep quantity and mood state were recorded using the BRUMS questionnaire. 10 out of the 12 participants experienced injuries; almost half of the participants had injuries that carried over a number of days. Mean sleep duration over the three days was 4.07 h, with an average of 0.78 injuries per day. Significant changes in mood were recorded across the three days, specifically a reduction in vigour (p = .029) and increase in fatigue (p = .014). Neither sleep quantity nor mental toughness was correlated with injury rate. Interestingly, sleep quantity was not related to changes in mood, as previously shown in ultra-marathons. Mental toughness had a moderate negative correlation (p < 0.01) with depression (-.623), reduced anger (-.616), confusion (-.558), increased vigour (.497) and tension (-.420) during the race. Success in this type of event involves significant psychological and physiological preparation to minimize the effects of sleep deprivation and avoidance of injuries.
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Affiliation(s)
- Scott Murray Graham
- School of Applied Sciences, Edinburgh Napier University, Edinburgh, Scotland.,School of Medicine, University of St. Andrews, St Andrews, Scotland
| | | | - Mairi McKinley
- School of Medicine, University of St. Andrews, St Andrews, Scotland
| | - Chris Connaboy
- Neuromuscular Research Laboratory, Warrior Human Performance Research Center, Department of Sports Medicine and Nutrition, University of Pittsburgh, Pittsburgh, PA, USA
| | - Georgios Andronikos
- School of Applied Sciences, Edinburgh Napier University, Edinburgh, Scotland
| | - Adam Susmarski
- Department of Physical Medicine and Rehabilitation, University of Pittsburgh Medical Center, Pittsburgh, PA, USA
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16
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Oral Hypertonic Saline Is Effective in Reversing Acute Mild-to-Moderate Symptomatic Exercise-Associated Hyponatremia. Clin J Sport Med 2020; 30:8-13. [PMID: 31855907 DOI: 10.1097/jsm.0000000000000573] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVES To determine whether oral administration of 3% hypertonic saline (HTS) is as efficacious as intravenous (IV) 3% saline in reversing symptoms of mild-to-moderate symptomatic exercise-associated hyponatremia (EAH) in athletes during and after a long-distance triathlon. DESIGN Noninferiority, open-label, parallel-group, randomized control trial to IV or oral HTS. We used permuted block randomization with sealed envelopes, containing the word either "oral" or "IV." SETTING Annual long-distance triathlon (3.8-km swim, 180-km bike, and 42-km run) at Mont-Tremblant, Quebec, Canada. PARTICIPANTS Twenty race finishers with mild to moderately symptomatic EAH. INDEPENDENT VARIABLES Age, sex, race finish time, and 9 clinical symptoms. MAIN OUTCOME MEASURES Time from treatment to discharge. METHODS We successfully randomized 20 participants to receive either an oral (n = 11) or IV (n = 9) bolus of HTS. We performed venipuncture to measure serum sodium (Na) at presentation to the medical clinic and at time of symptom resolution after the intervention. RESULTS The average time from treatment to discharge was 75.8 minutes (SD 29.7) for the IV treatment group and 50.3 minutes (SD 26.8) for the oral treatment group (t test, P = 0.02). Serum Na before and after treatment was not significantly different in both groups. There was no difference on presentation between groups in age, sex, or race finish time, both groups presented with an average of 6 symptoms. CONCLUSIONS Oral HTS is effective in reversing symptoms of mild-to-moderate hyponatremia in EAH.
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Knechtle B, Chlíbková D, Papadopoulou S, Mantzorou M, Rosemann T, Nikolaidis PT. Exercise-Associated Hyponatremia in Endurance and Ultra-Endurance Performance-Aspects of Sex, Race Location, Ambient Temperature, Sports Discipline, and Length of Performance: A Narrative Review. ACTA ACUST UNITED AC 2019; 55:medicina55090537. [PMID: 31455034 PMCID: PMC6780610 DOI: 10.3390/medicina55090537] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Revised: 08/15/2019] [Accepted: 08/21/2019] [Indexed: 12/05/2022]
Abstract
Exercise-associated hyponatremia (EAH) is defined as a plasma sodium concentration of <135 mmol/L during or after endurance and ultra-endurance performance and was first described by Timothy Noakes when observed in ultra-marathoners competing in the Comrades Marathon in South Africa in the mid-1980s. It is well-established that a decrease in plasma sodium concentration <135 mmol/L occurs with excessive fluid intake. Clinically, a mild hyponatremia will lead to no or very unspecific symptoms. A pronounced hyponatremia (<120 mmol/L) will lead to central nervous symptoms due to cerebral edema, and respiratory failure can lead to death when plasma sodium concentration reaches values of <110–115 mmol/L. The objective of this narrative review is to present new findings about the aspects of sex, race location, sports discipline, and length of performance. The prevalence of EAH depends on the duration of an endurance performance (i.e., low in marathon running, high to very high in ultra-marathon running), the sports discipline (i.e., rather rare in cycling, more frequent in running and triathlon, and very frequent in swimming), sex (i.e., increased in women with several reported deaths), the ambient temperature (i.e., very high in hot temperatures) and the country where competition takes place (i.e., very common in the USA, very little in Europe, practically never in Africa, Asia, and Oceania). A possible explanation for the increased prevalence of EAH in women could be the so-called Varon–Ayus syndrome with severe hyponatremia, lung and cerebral edema, which was first observed in marathon runners. Regarding the race location, races in Europe seemed to be held under rather moderate conditions whereas races held in the USA were often performed under thermally stressing conditions (i.e., greater heat or greater cold).
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Affiliation(s)
- Beat Knechtle
- Medbase St. Gallen Am Vadianplatz, 9001 St. Gallen, Switzerland.
- Institute of Primary Care, University of Zurich, 8091 Zurich, Switzerland.
| | - Daniela Chlíbková
- Centre of Sports Activities, Brno University of Technology, 61669 Brno, Czech Republic
| | - Sousana Papadopoulou
- Department of Nutritional Sciences and Dietetics, International Hellenic University, 57001 Thessaloniki, Greece
| | - Maria Mantzorou
- Food Science and Nutrition Department, University of the Aegean, 81400 Myrina, Greece
| | - Thomas Rosemann
- Institute of Primary Care, University of Zurich, 8091 Zurich, Switzerland
| | - Pantelis T Nikolaidis
- Exercise Physiology Laboratory, 18450 Nikaia, Greece
- School of Health and Caring Sciences, University of West Attica, 12243 Athens, Greece
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18
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Hermand E, Chabert C, Hue O. Ultra-endurance events in tropical environments and countermeasures to optimize performances and health. Int J Hyperthermia 2019; 36:753-760. [PMID: 31429600 DOI: 10.1080/02656736.2019.1635718] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
Physical performance in a tropical environment, combining high heat and humidity, is a difficult physiological challenge that requires specific preparation. The elevated humidity of a tropical climate impairs the thermoregulatory mechanisms by limiting the rate of sweat evaporation. Hence, a proper management of whole-body temperature is required to complete an ultra-endurance event in such an environment. In these long-duration events, which can last from 8 to 20 h, held in hot and humid settings, performance is tightly linked to the ability in maintaining an optimal hydration status. Indeed, the rate of withdrawal in these longer races was associated with lower water intake, and the majority of finishers exhibited alterations in electrolyte balance (e.g., sodium). Hence, this work reviews the effects on performance of high heat and humidity in two representative ultra-endurance sports, ultramarathons and long-distance triathlons, and several countermeasures to counteract the impact of these harsh environmental stresses and maintain a high level of performance, such as hydration, cooling strategies and heat acclimation.
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Affiliation(s)
- E Hermand
- Laboratory « Adaptations au Climat Tropical, Exercice et Santé » (EA 3596 ACTES), French West Indies University , Pointe-à-Pitre , France.,Laboratory « Handicap, Activité, Vieillissement, Autonomie, Environnement » (EA 6310 HAVAE), University of Limoges , Limoges , France
| | - C Chabert
- Laboratory « Adaptations au Climat Tropical, Exercice et Santé » (EA 3596 ACTES), French West Indies University , Pointe-à-Pitre , France
| | - O Hue
- Laboratory « Adaptations au Climat Tropical, Exercice et Santé » (EA 3596 ACTES), French West Indies University , Pointe-à-Pitre , France
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19
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Knechtle B, Chlíbková D, Nikolaidis PT. [Exercise-Associated Hyponatremia in Endurance Performance]. PRAXIS 2019; 108:615-632. [PMID: 31288661 DOI: 10.1024/1661-8157/a003261] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Exercise-Associated Hyponatremia in Endurance Performance Abstract. Exercise-associated hyponatremia is defined as a plasma sodium concentration of <135 mmol/l and was first described by Timothy Noakes at the Comrades Marathon in South Africa in the mid-1980s. A decrease in plasma sodium <135 mmol/l occurs with excessive fluid intake. Risk factors include long to very long endurance performance, extreme climatic conditions, female gender and competitions in the USA. Regarding its prevalence by sport, exercise-associated hyponatraemia tends to occur while swimming and running, but rarely when cycling. While mild exercise-associated hyponatremia does not lead to clinical symptoms, severe hyponatremia due to cerebral edema can lead to neurological deficits and even death. The best prevention of exercise-associated hyponatremia is the reduction of fluid intake during exercise.
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Affiliation(s)
- Beat Knechtle
- 1 Medbase St. Gallen Am Vadianplatz, St. Gallen
- 2 Institut für Hausarztmedizin, Universität Zürich, Zürich
| | - Daniela Chlíbková
- 3 Centre of Sports Activities, Brno University of Technology, Brno, Tschechien
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20
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Pomeranz D, Irwin C, Lipman GS. Large-Volume Hypertonic Saline for Empiric Treatment of Severe Exercise-Associated Hyponatremia in an Ultramarathon Runner. Curr Sports Med Rep 2019; 18:163-165. [DOI: 10.1249/jsr.0000000000000593] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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21
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Chlíbková D, Nikolaidis PT, Rosemann T, Knechtle B, Bednář J. Maintained Hydration Status After a 24-h Winter Mountain Running Race Under Extremely Cold Conditions. Front Physiol 2019; 9:1959. [PMID: 30687135 PMCID: PMC6336898 DOI: 10.3389/fphys.2018.01959] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 12/28/2018] [Indexed: 12/21/2022] Open
Abstract
Background: To date, no study has examined the hydration status of runners competing in a 24-h winter race under extremely cold environmental conditions. Therefore, the aim was to examine the effect of a 24-h race under an average temperature of -14.3°C on hydration status. Methods: Blood and urine parameters and body mass (BM) were assessed in 20 finishers (women, n = 6; men, n = 14) pre- and post-race. Results: Five (25%) ultra-runners had lower pre-race plasma sodium [Na+] and 11 (52%) had higher pre-race plasma potassium [K+] values than the reference ranges. Post-race plasma [Na+], plasma osmolality, urine osmolality and urine specific gravity remained stable (p > 0.05). The estimated fluid intake did not differ (p > 0.05) between women (0.30 ± 0.06 L/h) and men (0.46 ± 0.21 L/h). Runners with a higher number of completed ultra-marathons (r = -0.50, p = 0.024) and higher number of training kilometers (r = -0.68, p = 0.001) drank less than those with lower running experience. Pre-race and post-race plasma [Na+] were related to plasma osmolality (r = 0.65, p = 0.002, r = 0.69, p < 0.001, respectively) post-race, but not to fluid intake (p > 0.05). BM significantly decreased post-race (p = 0.002) and was not related to plasma [Na+] or fluid intake (p > 0.05). Post-race hematocrit and plasma [K+] decreased (p < 0.001) and transtubular potassium gradient increased (p = 0.008). Higher pre-race plasma [K+] was related to higher plasma [K+] loss post-race (p = -0.85, p < 0.001). Conclusion: Hydration status remained stable despite the extremely cold winter weather conditions. Overall fluid intake was probably sufficient to replenish the hydration needs of 24-h runners. Current recommendations may be too high for athletes competing in extremely cold conditions.
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Affiliation(s)
- Daniela Chlíbková
- Centre of Sports Activities, Brno University of Technology, Brno, Czechia
| | | | | | - Beat Knechtle
- Exercise Physiology Laboratory, Nikaia, Greece.,Medbase St. Gallen Am Vadianplatz, St. Gallen, Switzerland
| | - Josef Bednář
- Faculty of Mechanical Engineering, Brno University of Technology, Brno, Czechia
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22
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Nikolaidis PT, Veniamakis E, Rosemann T, Knechtle B. Nutrition in Ultra-Endurance: State of the Art. Nutrients 2018; 10:nu10121995. [PMID: 30558350 PMCID: PMC6315825 DOI: 10.3390/nu10121995] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 12/02/2018] [Accepted: 12/11/2018] [Indexed: 11/18/2022] Open
Abstract
Athletes competing in ultra-endurance sports should manage nutritional issues, especially with regards to energy and fluid balance. An ultra-endurance race, considered a duration of at least 6 h, might induce the energy balance (i.e., energy deficit) in levels that could reach up to ~7000 kcal per day. Such a negative energy balance is a major health and performance concern as it leads to a decrease of both fat and skeletal muscle mass in events such as 24-h swimming, 6-day cycling or 17-day running. Sport anemia caused by heavy exercise and gastrointestinal discomfort, under hot or cold environmental conditions also needs to be considered as a major factor for health and performance in ultra-endurance sports. In addition, fluid losses from sweat can reach up to 2 L/h due to increased metabolic work during prolonged exercise and exercise under hot environments that might result in hypohydration. Athletes are at an increased risk for exercise-associated hyponatremia (EAH) and limb swelling when intake of fluids is greater than the volume lost. Optimal pre-race nutritional strategies should aim to increase fat utilization during exercise, and the consumption of fat-rich foods may be considered during the race, as well as carbohydrates, electrolytes, and fluid. Moreover, to reduce the risk of EAH, fluid intake should include sodium in the amounts of 10–25 mmol to reduce the risk of EAH and should be limited to 300–600 mL per hour of the race.
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Affiliation(s)
- Pantelis T Nikolaidis
- Laboratory of Exercise Testing, Hellenic Air Force Academy, 13671 Dekelia, Greece.
- Exercise Physiology Laboratory, 18450 Nikaia, Greece.
| | - Eleftherios Veniamakis
- Department of Nutrition and Dietetics, Technological Educational Institute, 72300 Sitia, Greece.
| | - Thomas Rosemann
- Institute of General Practice and for Health Services Research, University of Zurich, 8091 Zurich, Switzerland.
| | - Beat Knechtle
- Institute of General Practice and for Health Services Research, University of Zurich, 8091 Zurich, Switzerland.
- Medbase St. Gallen Am Vadianplatz, 9001 St. Gallen, Switzerland.
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Shchekochikhin DY, Kozlovskaya NL, Kopylov FY, Syrkin AL, Shilov EM. Hyponatremia: A clinical approach. TERAPEVT ARKH 2017; 89:134-140. [DOI: 10.17116/terarkh2017898134-140] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Hyponatremia is the most common electrolyte metabolic abnormality in clinical practice. The unfavorable course of many diseases is associated with hyponatremia. Acute severe hyponatremia is life-threatening because cerebral edema may develop. Less obvious chronic hyponatremia increases the risk of balance problems, falls and fractures, especially in elderly patients. In any occasion, hyponatremia should not be now regarded only as a laboratory phenomenon in critically ill patients, but it necessitates a thorough clinical analysis of each individual case and appropriate therapy. The paper presents approaches to diagnosing and treating hyponatremia in various clinical situations.
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Krabak BJ, Lipman GS, Waite BL, Rundell SD. Exercise-Associated Hyponatremia, Hypernatremia, and Hydration Status in Multistage Ultramarathons. Wilderness Environ Med 2017; 28:291-298. [PMID: 28781178 DOI: 10.1016/j.wem.2017.05.008] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 03/29/2017] [Accepted: 05/25/2017] [Indexed: 11/30/2022]
Abstract
OBJECTIVE Dysnatremia and altered hydration status are potentially serious conditions that have not been well studied in multistage ultramarathons. The purpose of this study was to assess the incidence and prevalence of exercise-associated hyponatremia (EAH) (Na+ <135 mmol·L-1) and hypernatremia (Na+ >145 mmol·L-1) and hydration status during a multistage ultramarathon. METHODS This study involved a prospective observational cohort study of runners competing in a 250-km (155-mile) multistage ultramarathon (in the Jordan, Atacama, or Gobi Desert). Prerace body weight and poststage (stage [S] 1 [42 km], S3 [126 km], and S5 [250 km]) body weight and serum sodium concentration levels were obtained from 128 runners. RESULTS The prevalence of EAH per stage was 1.6% (S1), 4.8% (S3), and 10.1% (S5) with a cumulative incidence of 14.8%. Per-stage prevalence of hypernatremia was 35.2% (S1), 20.2% (S3), and 19.3% (S5) with a cumulative incidence of 52.3%. Runners became more dehydrated (weight change <-3%) throughout the race (S1=22.1%; S3=51.2%; S5=53.5%). Body weight gain correlated with EAH (r=-0.21, P = .02). Nonfinishers of S3 were significantly more likely to have EAH compared with finishers (75% vs 5%, P = .001), but there was no difference in either EAH or hypernatremia between nonfinishers and finishers of S5. CONCLUSIONS The incidence of EAH in multistage ultramarathons was similar to marathons and single-stage ultramarathons, but the cumulative incidence of hypernatremia was 3 times greater than that of EAH. EAH was associated with increased weight gain (overhydration) in early stage nonfinishers and postrace finishers.
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Affiliation(s)
- Brian J Krabak
- Department of Rehabilitation, Orthopedics and Sports Medicine, University of Washington and Seattle Children's Sports Medicine, Seattle, WA (Dr Krabak).
| | - Grant S Lipman
- Department of Emergency Medicine, Stanford University School of Medicine, Stanford, CA (Dr Lipman)
| | - Brandee L Waite
- Department of Physical Medicine and Rehabilitation, University of California, Davis Sports Medicine, Sacramento, CA (Dr Waite)
| | - Sean D Rundell
- Department of Rehabilitation Medicine, University of Washington, Seattle, WA (Dr Rundell)
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25
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Hew-Butler T, Loi V, Pani A, Rosner MH. Exercise-Associated Hyponatremia: 2017 Update. Front Med (Lausanne) 2017; 4:21. [PMID: 28316971 PMCID: PMC5334560 DOI: 10.3389/fmed.2017.00021] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2016] [Accepted: 02/16/2017] [Indexed: 12/21/2022] Open
Abstract
Exercise-associated hyponatremia (EAH) was initially described in the 1980s in endurance athletes, and work done since then has conclusively identified that overdrinking beyond thirst and non-osmotic arginine vasopressin release are the most common etiologic factors. In recent years, EAH has been described in a broader variety of athletic events and also has been linked to the development of rhabdomyolysis. The potential role of volume and sodium depletion in a subset of athletes has also been described. This review focuses on the most recent literature in the field of EAH and summarizes key new findings in the epidemiology, pathophysiology, treatment, and prevention of this condition.
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Affiliation(s)
| | - Valentina Loi
- SC Nephrology and Dialysis, Brotzu Hospital , Cagliari , Italy
| | - Antonello Pani
- SC Nephrology and Dialysis, Brotzu Hospital , Cagliari , Italy
| | - Mitchell H Rosner
- Department of Medicine, University of Virginia Health System , Charlottesville, VA , USA
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Wijkström J, González-Quiroz M, Hernandez M, Trujillo Z, Hultenby K, Ring A, Söderberg M, Aragón A, Elinder CG, Wernerson A. Renal Morphology, Clinical Findings, and Progression Rate in Mesoamerican Nephropathy. Am J Kidney Dis 2017; 69:626-636. [PMID: 28126239 DOI: 10.1053/j.ajkd.2016.10.036] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 10/17/2016] [Indexed: 12/12/2022]
Abstract
BACKGROUND Mesoamerican nephropathy (MeN) is a chronic kidney disease affecting rural inhabitants in Central America. We have previously described the renal morphology in 8 patients from El Salvador. To confirm the renal pathology, we have studied kidney biopsies from patients with MeN in Nicaragua. Follow-up urine and blood samples from both biopsy studies were collected to investigate the natural history. STUDY DESIGN Case series. SETTINGS & PARTICIPANTS In the kidney biopsy study, 19 male sugarcane workers in Nicaragua with suspected MeN were investigated with questionnaires, kidney biopsies, and blood and urine analysis. Inclusion criteria were age 20 to 65 years and plasma creatinine level of 1.13 to 2.49mg/dL or estimated glomerular filtration rate (eGFR) of 30 to 80mL/min/1.73m2. Exclusion criteria were proteinuria with protein excretion > 3g/24 h, uncontrolled hypertension, diabetes mellitus, or other known kidney disease. In the follow up-study, blood and urine from the kidney biopsy study in Nicaragua (n=18) and our previous biopsy study of MeN cases in El Salvador (n=7) were collected 1 to 1.5 and 2 to 2.5 years after biopsy, respectively. OUTCOMES Renal morphology, clinical, and biochemical characteristics, change in eGFR per year. MEASUREMENTS eGFR was calculated using the CKD-EPI creatinine (eGFRcr), cystatin C (eGFRcys), and creatinine-cystatin C (eGFRcr-cys) equations. RESULTS In the kidney biopsy study, participants had a mean eGFRcr of 57 (range, 33-96) mL/min/1.73m2. 47% had low plasma sodium and 21% had low plasma potassium levels. 16 kidney biopsies were representative and showed glomerulosclerosis (mean, 38%), glomerular hypertrophy, and signs of chronic glomerular ischemia. Mild to moderate tubulointerstitial damage and mostly mild vascular changes were seen. In the follow up-study, median duration of follow-up was 13 (range, 13-27) months. Mean change in eGFRcr was -4.4±8.4 (range, -27.7 to 10.2) mL/min/1.73m2 per year. Most patients had stopped working with sugarcane cultivation. LIMITATIONS 3 biopsy specimens had 4 or fewer glomeruli. CONCLUSIONS This study confirms the renal morphology of MeN: chronic glomerular and tubulointerstitial damage with glomerulosclerosis and chronic glomerular ischemia. Follow-up data show that eGFRs, on average, deteriorated.
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Affiliation(s)
- Julia Wijkström
- Division of Renal Medicine, Department of Clinical Sciences, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden
| | - Marvin González-Quiroz
- Research Center on Health, Work and Environment, National Autonomous University of Nicaragua at León, León, Nicaragua; Department of Non-communicable Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Mario Hernandez
- Department of Pediatrics, National Autonomous University of Nicaragua at León, León, Nicaragua
| | - Zulma Trujillo
- Servicio de Nefrología, Hospital Nacional Rosales, San Salvador, El Salvador
| | - Kjell Hultenby
- Division of CRC, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Anneli Ring
- Clinical Pathology and Cytology, Karolinska University Hospital, Stockholm, Sweden
| | - Magnus Söderberg
- Clinical Pathology and Cytology, Karolinska University Hospital, Stockholm, Sweden; Drug Safety and Metabolism, AstraZeneca, Mölndal, Stockholm, Sweden
| | - Aurora Aragón
- Research Center on Health, Work and Environment, National Autonomous University of Nicaragua at León, León, Nicaragua
| | - Carl-Gustaf Elinder
- Division of Renal Medicine, Department of Clinical Sciences, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden
| | - Annika Wernerson
- Division of Renal Medicine, Department of Clinical Sciences, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden; Clinical Pathology and Cytology, Karolinska University Hospital, Stockholm, Sweden.
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Krabak BJ, Parker KM, DiGirolamo A. Exercise-Associated Collapse: Is Hyponatremia in Our Head? PM R 2017; 8:S61-8. [PMID: 26972268 DOI: 10.1016/j.pmrj.2015.10.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 09/25/2015] [Accepted: 10/04/2015] [Indexed: 11/18/2022]
Abstract
Exercise-associated hyponatremia (EAH) is one of the most common causes of exercise-associated collapse. The primary pathogenesis of EAH is largely the result of excessive fluid intake but is influenced by other factors, including hormonal abnormalities (ie, inappropriate arginine vasopressin secretion), renal abnormalities, and mobilization of sodium stores. Early recognition of EAH is crucial to appropriate treatment, because symptoms are varied and may be confused with other causes of exercise-associated collapse. Onsite testing of [Na+] will confirm the diagnosis but is not always available. Rapid treatment of EAH will depend upon the type and severity of symptoms. Treatment protocols range from fluid restriction or oral hypertonic fluids for mild symptoms to intravenous hypertonic fluids for more severe symptoms. Preventative strategies should emphasize fluid consumption based on thirst and athlete/coach/staff education regarding proper hydration practices.
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Affiliation(s)
- Brian J Krabak
- Rehabilitation, Orthopedics and Sports Medicine, University of Washington and Seattle Children's Sports Medicine, 3800 Montlake Boulevard NE, Box 354060, Seattle, WA 98105; and University of Washington and Seattle University(∗).
| | - Kelsey M Parker
- University of Washington and Seattle Children's Sports Medicine, Seattle, WA(†)
| | - Anthony DiGirolamo
- University of Washington and Seattle Children's Sports Medicine, Seattle, WA(‡)
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Koenders EE, Franken CPG, Cotter JD, Thornton SN, Rehrer NJ. Restricting dietary sodium reduces plasma sodium response to exercise in the heat. Scand J Med Sci Sports 2016; 27:1213-1220. [DOI: 10.1111/sms.12748] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/14/2016] [Indexed: 01/25/2023]
Affiliation(s)
- E. E. Koenders
- Department of Physiology; Radboud University; Nijmegen The Netherlands
| | - C. P. G. Franken
- Department of Physiology; Radboud University; Nijmegen The Netherlands
| | - J. D. Cotter
- School of Physical Education Sport & Exercise Sciences; Otago University; Dunedin New Zealand
| | - S. N. Thornton
- Faculty of Sciences; University of Lorraine; INSERM UMR_S.1116; Nancy France
| | - N. J. Rehrer
- School of Physical Education Sport & Exercise Sciences; Otago University; Dunedin New Zealand
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Sedgwick PE, Wortley GC, Wright JM, Asplund C, William OR, Usman S. Medical Clearance for Desert and Land Sports, Adventure, and Endurance Events. Wilderness Environ Med 2016; 26:S47-54. [PMID: 26617378 DOI: 10.1016/j.wem.2015.09.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 06/12/2015] [Indexed: 11/15/2022]
Abstract
Endurance events are increasing in popularity in wilderness and remote settings, and participants face a unique set of potential risks for participation. The purpose of this article is to outline these risks and allow the practitioner to better guide the wilderness adventurer who is anticipating traveling to a remote or desert environment.
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Affiliation(s)
- Peter E Sedgwick
- Central Maine Sports Medicine (A Clinical Division of CMMC), Lewiston, Maine (Dr Sedgwick).
| | - George C Wortley
- Lynchburg Family Medicine Residency, Lynchburg, Virginia (Dr Wortley)
| | - Justin M Wright
- Department of Family and Community Medicine, Paul L. Foster School of Medicine, El Paso, Texas (Dr Wright)
| | - Chad Asplund
- Family Medicine, Georgia Regents University, Augusta, Georgia (Dr Asplund)
| | - O Roberts William
- Department of Family Medicine and Community Health, University of Minnesota, Minneapolis, Minnesota (Dr Roberts)
| | - Saif Usman
- Primary Care Sports Medicine, Marymount University, MedStar Medical Group, Arlington, Virginia (Dr Usman)
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Shin KA, Kim YJ. Safety Assessment of Osmolality Concentration and Biochemical Factors Changes in Electrolyte Metabolism during an Ultra-marathon (100 km). KOREAN JOURNAL OF CLINICAL LABORATORY SCIENCE 2016. [DOI: 10.15324/kjcls.2016.48.2.137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Affiliation(s)
- Kyung-A Shin
- Department of Clinical Laboratory Science, Shinsung University, Dangjin 31801, Korea
| | - Young-Joo Kim
- Department of Rehabilitation Medicine, Sanggye-Paik Hospital, Seoul 01757, Korea
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Hoffman MD, Stuempfle KJ. Sodium Supplementation and Exercise-Associated Hyponatremia during Prolonged Exercise. Med Sci Sports Exerc 2016; 47:1781-7. [PMID: 25551404 DOI: 10.1249/mss.0000000000000599] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE This work examines whether sodium supplementation is important in prevention of hyponatremia during continuous exercise up to 30 h and whether any distinguishing characteristics of those developing hyponatremia could be identified. METHODS Participants of the 161-km Western States Endurance Run underwent body weight measurements before, during, and after the race, completed a postrace questionnaire about drinking strategies and use of sodium supplementation during four race segments, and underwent analysis of postrace serum sodium concentration. RESULTS The postrace questionnaire was completed by 74.5% of the 376 starters, a postrace blood sample was provided by 61.1% of the 296 finishers, and 53.0% of finishers completed the postrace survey and also provided a postrace blood sample. Among this population, the incidence of hyponatremia among finishers was 6.6% and sodium supplements were used by 93.9% of the runners. Postrace serum sodium concentration was found to be directly related to the rate of sodium intake in supplements (r = 0.24, P = 0.0027) and indirectly related to the percentage change in body weight from immediately before the race start (r = -0.19, P = 0.010). There was no difference in rate of sodium intake in supplements between the hyponatremic and normonatremic finishers, and none of the hyponatremic finishers lost >4.3% body weight. Hyponatremic finishers were not distinguished from normonatremic or hypernatremic finishers by other runner characteristics considered, drinking strategies, or gastrointestinal symptoms of nausea and vomiting. CONCLUSIONS We conclude that a low sodium intake in supplements has minimal responsibility for development of hyponatremia during continuous exercise up to 30 h, whereas overhydration is the primary characteristic of those developing hyponatremia. Therefore, avoiding overhydration seems to be the most important means for preventing hyponatremia under these conditions.
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Affiliation(s)
- Martin D Hoffman
- 1Department of Physical Medicine and Rehabilitation, Department of Veterans Affairs, Northern California Health Care System, and University of California Davis Medical Center, Sacramento, CA; and 2Health Sciences Department, Gettysburg College, Gettysburg, PA
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Abstract
Endurance events are increasing in popularity in wilderness and remote settings, and participants face a unique set of potential risks for participation. The purpose of this article is to outline these risks and allow the practitioner to better guide the wilderness adventurer who is anticipating traveling to a remote or desert environment.
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Bennett BL, Hew-Butler T, Hoffman MD, Rogers IR, Rosner MH. Wilderness Medical Society practice guidelines for treatment of exercise-associated hyponatremia: 2014 update. Wilderness Environ Med 2015; 25:S30-42. [PMID: 25498260 DOI: 10.1016/j.wem.2014.08.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Accepted: 08/21/2014] [Indexed: 10/24/2022]
Abstract
Exercise-associated hyponatremia (EAH) is defined by a serum or plasma sodium concentration below the normal reference range of 135 mmol/L that occurs during or up to 24 hours after prolonged physical activity. It is reported to occur in individual physical activities or during organized endurance events conducted in austere environments in which medical care is limited and often not available, and patient evacuation to definitive care is often greatly delayed. Rapid recognition and appropriate treatment are essential in the severe form to ensure a positive outcome. Failure in this regard is a recognized cause of event-related fatality. In an effort to produce best practice guidelines for EAH in the austere environment, the Wilderness Medical Society convened an expert panel. The panel was charged with the development of evidence-based guidelines for management of EAH. Recommendations are made regarding the situations when sodium concentration can be assessed in the field and when these values are not known. These recommendations are graded on the basis of the quality of supporting evidence and balance between the benefits and risks/burdens for each parameter according to the methodology stipulated by the American College of Chest Physicians. This is an updated version of the original WMS Practice Guidelines for Treatment of Exercise-Associated Hyponatremia published in Wilderness & Environmental Medicine 2013;24(3):228-240.
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Affiliation(s)
- Brad L Bennett
- Military & Emergency Medicine Department, F. Edward Hebert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD (Dr Bennett).
| | | | - Martin D Hoffman
- Department of Physical Medicine & Rehabilitation, Department of Veterans Affairs, Northern California Health Care System, and University of California Davis Medical Center, Sacramento, CA (Dr Hoffman)
| | - Ian R Rogers
- St. John of God Murdoch Hospital & University of Notre Dame, Murdoch, Western Australia (Dr Rogers)
| | - Mitchell H Rosner
- Division of Nephrology, University of Virginia, Charlottesville, VA (Dr Rosner)
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Knechtle B, Knechtle R, Stiefel M, Zingg MA, Rosemann T, Rüst CA. Variables that influence Ironman triathlon performance - what changed in the last 35 years? Open Access J Sports Med 2015; 6:277-90. [PMID: 26346992 PMCID: PMC4556299 DOI: 10.2147/oajsm.s85310] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
OBJECTIVE This narrative review summarizes findings for Ironman triathlon performance and intends to determine potential predictor variables for Ironman race performance in female and male triathletes. METHODS A literature search was performed in PubMed using the terms "Ironman", "triathlon", and "performance". All resulting articles were searched for related citations. RESULTS Age, previous experience, sex, training, origin, anthropometric and physiological characteristics, pacing, and performance in split disciplines were predictive. Differences exist between the sexes for anthropometric characteristics. The most important predictive variables for a fast Ironman race time were age of 30-35 years (women and men), a fast personal best time in Olympic distance triathlon (women and men), a fast personal best time in marathon (women and men), high volume and high speed in training where high volume was more important than high speed (women and men), low body fat, low skin-fold thicknesses and low circumference of upper arm (only men), and origin from the United States of America (women and men). CONCLUSION These findings may help athletes and coaches to plan an Ironman triathlon career. Age and previous experience are important to find the right point in the life of a triathlete to switch from the shorter triathlon distances to the Ironman distance. Future studies need to correlate physiological characteristics such as maximum oxygen uptake with Ironman race time to investigate their potential predictive value and to investigate socio-economic aspects in Ironman triathlon.
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Affiliation(s)
- Beat Knechtle
- Gesundheitszentrum St Gallen, St Gallen, Switzerland ; Institute of Primary Care, University of Zurich, Zurich, Switzerland
| | - Raphael Knechtle
- Institute of Primary Care, University of Zurich, Zurich, Switzerland
| | - Michael Stiefel
- Institute of Primary Care, University of Zurich, Zurich, Switzerland
| | | | - Thomas Rosemann
- Institute of Primary Care, University of Zurich, Zurich, Switzerland
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Lemos R, Rosa Neto F, Mara LSD, Lineburger AA, Carvalho TD, Ramos R. Peso corporal e estado hídrico de triatletas no Ironman Brasil: Um fator de correção. REV BRAS MED ESPORTE 2015. [DOI: 10.1590/1517-869220152104137358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
INTRODUÇÃO: O triatlo Ironman é uma prova de longa duração em que comumente se observam alterações hidroeletrolíticas. A desidratação e hiponatremia são prevalentes e o diagnóstico diferencial entre elas deve levar em conta a variação de peso corporal do atleta. Contudo, deve-se considerar também que as variações são um somatório de fontes hídricas e não hídricas, sendo necessário aplicar um fator de correção para avaliação do real estado hídrico do atleta. Objetivo: Avaliar o estado hídrico do atleta baseado nas variações de peso corporal sem e com aplicação de fator de correção.MÉTODO: Vinte e seis atletas foram pesados em três momentos distintos (dois dias antes da prova, imediatamente antes e após a realização). O estado hídrico foi classificado com base no cálculo da variação percentual de peso corporal isolado e com aplicação do fator de correção de 1 kg proporcional ao atleta de 70 kg. Além disso, foram registrados os principais sinais clínicos e sintomas referidos.RESULTADOS: Nas 48 horas que antecederam a largada houve um ganho médio de peso de 1,2 kg. Após a prova, vinte e três (88,4%) atletas foram classificados como desidratados inicialmente, porém após a aplicação do fator de correção à variação do peso, esse número caiu para 12 (46,1%). Dos classificados como desidratação severa houve redução de 7 (26,2%) para nenhum atleta. Dez atletas (3,8%) apresentaram sinais e sintomas de desidratação.CONCLUSÃO: A classificação do estado de hidratação baseado nas perdas hídricas durante a prova foi significativamente modificado pela aplicação do fator de correção, sendo sua utilização justificada pelas evidências de que o ganho de peso nas 48 horas anteriores à prova está possivelmente relacionado ao acúmulo muscular de glicogênio e água (fontes não hídricas intravasculares).
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Affiliation(s)
| | | | | | | | | | - Renata Ramos
- Universidade do Estado de Santa Catarina, Brazil
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Abstract
OBJECTIVE To determine body weight and serum [Na] changes in runners completing an 85-km mountain run, particularly with reference to their "in-race" hydration protocols. DESIGN Prospective observational cohort study. SETTING Cradle Mountain Run, Tasmania, Australia, February 2011. PARTICIPANTS Forty-four runners (86% of starters) prospectively enrolled, with 41 runners (80% of starters) eligible for inclusion in final data set. MAIN OUTCOME MEASURES Body weight change, serum sodium concentration change, and hydration plan (according to thirst vs preplanned fluid consumption). RESULTS There was 1 case of exercise-associated hyponatremia (EAH) [postrace [Na], 132 mmol/L]. This runner was asymptomatic. There was a strongly significant correlation between the change in serum [Na] and body weight change during the race. There was a significant inverse correlation between serum [Na] and volume of fluid consumed. Change of serum [Na] was not correlated with the proportion of water versus electrolyte drink consumed. Runners drinking to thirst consumed significantly lower average fluid volumes and had higher postrace serum [Na] than those complying with a preplanned hydration protocol (142 mmol/L vs 139 mmol/L). More experienced runners tended to drink to thirst. CONCLUSIONS There was a 2% incidence of EAH in this study. Serum [Na] change during an 85-km mountain run was inversely correlated with the volume of fluid consumed. The results provide further evidence that EAH is a dilutional hyponatremia caused by excessive consumption of hypotonic fluids. Drinking to thirst represents a safe hydration strategy for runners in a wilderness environment. CLINICAL RELEVANCE Drinking to thirst during endurance running events should be promoted as a safe hydration practice.
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Hew-Butler T, Rosner MH, Fowkes-Godek S, Dugas JP, Hoffman MD, Lewis DP, Maughan RJ, Miller KC, Montain SJ, Rehrer NJ, Roberts WO, Rogers IR, Siegel AJ, Stuempfle KJ, Winger JM, Verbalis JG. Statement of the Third International Exercise-Associated Hyponatremia Consensus Development Conference, Carlsbad, California, 2015. Clin J Sport Med 2015; 25:303-20. [PMID: 26102445 DOI: 10.1097/jsm.0000000000000221] [Citation(s) in RCA: 121] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Tamara Hew-Butler
- *Exercise Science Program, Oakland University, Rochester, Michigan; †Division of Nephrology, University of Virginia Health System, Charlottesville, Virginia; ‡Department of Sports Medicine, West Chester University, West Chester, Pennsylvania; §The Vitality Group, Chicago, Illinois; ¶Department of Physical Medicine and Rehabilitation, VA Northern California Health Care System and University of California Davis, Sacramento, California; ‖Family Medicine Residency Program, Via Christi Hospitals Wichita, Inc, Wichita, Kansas; **Department of Sport and Exercise Nutrition, Loughborough University, Leicestershire, United Kingdom; ††Athletic Training Program, Central Michigan University, Mount Pleasant, Michigan; ‡‡Military Nutrition Division, United States Army Research Institute of Environmental Medicine, Natick, Massachusetts; §§School of Physical Education, Sport and Exercise Science, University of Otago, Dunedin, New Zealand; ¶¶Department of Family Medicine and Community Health, University of Minnesota, Minneapolis, Minnesota; ‖‖Department of Emergency Medicine, St John of God Murdoch Hospital and University of Notre Dame, Perth, Western Australia; ***Department of Internal Medicine, Harvard Medical School, Boston, Massachusetts; †††Health Sciences Department, Gettysburg College, Gettysburg, Pennsylvania; ‡‡‡Department of Family Medicine, Loyola University Chicago Stritch School of Medicine, Chicago, Illinois; and §§§Department of Endocrinology and Metabolism, Georgetown University Medical Center, Washington, District of Columbia
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Incidence of Exercise-Associated Hyponatremia and Its Association With Nonosmotic Stimuli of Arginine Vasopressin in the GNW100s Ultra-endurance Marathon. Clin J Sport Med 2015; 25:347-54. [PMID: 25318530 DOI: 10.1097/jsm.0000000000000144] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVES (1) To examine the incidence of exercise-associated hyponatremia (EAH) during and after an ultramarathon and (2) to evaluate hypothesized nonosmotic stimuli [interleukin-6 (IL-6), hypoglycemia, ambient temperature] with arginine vasopressin (AVP) concentrations in hyponatremic versus normonatremic runners. DESIGN Prospective cohort study. SETTING The Great North Walk 100s ultramarathons. PARTICIPANTS Fifteen runners participated in either 103.7- or 173.7-km ultramarathons. MAIN OUTCOME MEASURES Serum sodium concentration ([Na]) and AVP concentration. Secondary outcome measures included IL-6, blood glucose, ambient temperature, weight change, fluid consumption, and use of nonsteroidal anti-inflammatory drugs (NSAIDs). RESULTS Postrace EAH incidence was 4 of 15 runners, whereas EAH incidence at any point during the race was in 10 of 15 runners. A significant positive correlation was noted between AVP and IL-6 (r = 0.31, P < 0.05) but not between AVP and blood glucose (r = 0.09, nonsignificant) or ambient temperature (r = -0.12, NS). Subgroup analysis revealed that the correlation between AVP and IL-6 was significant in hyponatremic (r = 0.37, P < 0.05) but not normonatremic runners (r = 0.31, NS). Hyponatremic runners lost less weight than normonatremic runners (2.5 vs. 3.7 kg, P < 0.05, respectively) despite similar fluid consumption. Seven of 10 hyponatremic runners consumed NSAIDs versus 0 of 5 normonatremic runners. CONCLUSIONS Exercise-associated hyponatremia incidence mid-race is higher than postrace, suggesting that 40% of runners are able to self-correct low serum [Na] status during an ultramarathon. Interleukin-6 seems to be the main nonosmotic stimulus associated with AVP in hyponatremic runners. Nonsteroidal anti-inflammatory ingestion is more common in hyponatremic versus normonatremic runners. CLINICAL RELEVANCE Exercise-associated hyponatremia associated with nonosmotic AVP secretion may be more common during ultramarathon races without discriminatory clinical symptomatology.
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Tan DW, Yap SH, Wang M, Fan PW, Teo YS, Krishnasamy P, Krishna L, Hew-Butler T, Lee JKW. Body Mass Changes Across a Variety of Running Race Distances in the Tropics. SPORTS MEDICINE - OPEN 2015; 2:26. [PMID: 27478761 PMCID: PMC4951505 DOI: 10.1186/s40798-016-0050-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 07/05/2016] [Indexed: 11/10/2022]
Abstract
BACKGROUND Current literature evaluating body mass (BM) changes across a variety of running race distances is limited. The primary objective of this study was to profile the range of BM changes across race distances. The secondary objective was to evaluate the prevalence of exercise-associated hyponatremia (EAH) in runners admitted to the on-site medical tent following participation of race events of different distances. METHODS A total of 1934 runners across seven footrace categories (10-, 21-, 25-, 42-, 50-, 84-, and 100-km) were included in the study. One thousand eight hundred eighty-seven runners had their BM measured before and after each race. Blood sodium concentrations were measured from the remaining 47 symptomatic runners admitted to the on-site medical tents and did not complete the race. RESULTS In terms of hydration status, 106 (6 %) were overhydrated, 1377 (73 %) were euhydrated, and 404 (21 %) were dehydrated. All race distances exhibited similar percentage of overhydrated runners (5 % in 10 km, 3 % in 21 km, 5 % in 25 km, 6 % in 42 km, 8 % in 50 km, 7 % in 84 km, and 6 % in 100 km). Forty-seven runners were admitted to the medical tents. Eight (17 %) were diagnosed with EAH (4 from 42 km, 2 from 84 km, 2 from 100 km), 38 (81 %) were normonatremic, and 1 (2 %) was hypernatremic. The % ΔBM across all races ranged from -8.0 to 4.1 % with a greater decrement noted in the 42-, 50-, 84-, and 100-km categories. CONCLUSIONS Approximately 3-8 % runners had increased post-race BM, suggesting overhydration regardless of race distance. Symptomatic EAH was seen at race distances at or above 42 km, where BM changes demonstrated the widest range of values.
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Affiliation(s)
- Desmond Wei Tan
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Si Hui Yap
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Mingchang Wang
- National University Hospital Sports Centre, National University Health System, Singapore, Singapore
| | - Priscilla Weiping Fan
- Defence Medical & Environmental Research Institute, DSO National Laboratories, Singapore, Singapore
| | - Ya Shi Teo
- Defence Medical & Environmental Research Institute, DSO National Laboratories, Singapore, Singapore
| | | | - Lingaraj Krishna
- National University Hospital Sports Centre, National University Health System, Singapore, Singapore
| | | | - Jason Kai Wei Lee
- Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Defence Medical & Environmental Research Institute, DSO National Laboratories, Singapore, Singapore
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
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Deldicque L, Francaux M. Recommendations for Healthy Nutrition in Female Endurance Runners: An Update. Front Nutr 2015; 2:17. [PMID: 26075206 PMCID: PMC4443719 DOI: 10.3389/fnut.2015.00017] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Accepted: 05/12/2015] [Indexed: 01/01/2023] Open
Abstract
The purpose of this review is to present the basic principles of a healthy nutrition in female endurance runner enriched by the latest scientific recommendations. Female endurance runners are a specific population of athletes who need to take specifically care of daily nutrition due to the high load of training and the necessity to keep a rather low body mass. This paradoxical situation can create some nutritional imbalances and deficiencies. Female endurance athletes should pay attention to their total energy intake, which is often lower than their energy requirement. The minimal energy requirement has been set to 45 kcal/kg fat free mass/day plus the amount of energy needed for physical activity. The usual recommended amount of 1.2–1.4 g protein/kg/day has recently been questioned by new findings suggesting that 1.6 g/kg/day would be more appropriate for female athletes. Although a bit less sensitive to carbohydrate loading than their male counterparts, female athletes can benefit from this nutritional strategy before a race if the amount of carbohydrates reaches 8 g/kg/day and if their daily total energy intake is sufficient. A poor iron status is a common issue in female endurance runners but iron-enriched food as well as iron supplementation may help to counterbalance this poor status. Finally, they should also be aware that they may be at risk for low calcium and vitamin D levels.
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Affiliation(s)
- Louise Deldicque
- Exercise Physiology Research Group, Department of Kinesiology, Faber, KU Leuven , Leuven , Belgium
| | - Marc Francaux
- Institute of Neuroscience, Université catholique de Louvain , Louvain-la-Neuve , Belgium
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Knechtle B, Zingg MA, Rosemann T, Stiefel M, Rüst CA. What predicts performance in ultra-triathlon races? - a comparison between Ironman distance triathlon and ultra-triathlon. Open Access J Sports Med 2015; 6:149-59. [PMID: 26056498 PMCID: PMC4445872 DOI: 10.2147/oajsm.s79273] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Objective This narrative review summarizes recent intentions to find potential predictor variables for ultra-triathlon race performance (ie, triathlon races longer than the Ironman distance covering 3.8 km swimming, 180 km cycling, and 42.195 km running). Results from studies on ultra-triathletes were compared to results on studies on Ironman triathletes. Methods A literature search was performed in PubMed using the terms “ultra”, “triathlon”, and “performance” for the aspects of “ultra-triathlon”, and “Ironman”, “triathlon”, and “performance” for the aspects of “Ironman triathlon”. All resulting papers were searched for related citations. Results for ultra-triathlons were compared to results for Ironman-distance triathlons to find potential differences. Results Athletes competing in Ironman and ultra-triathlon differed in anthropometric and training characteristics, where both Ironmen and ultra-triathletes profited from low body fat, but ultra-triathletes relied more on training volume, whereas speed during training was related to Ironman race time. The most important predictive variables for a fast race time in an ultra-triathlon from Double Iron (ie, 7.6 km swimming, 360 km cycling, and 84.4 km running) and longer were male sex, low body fat, age of 35–40 years, extensive previous experience, a fast time in cycling and running but not in swimming, and origins in Central Europe. Conclusion Any athlete intending to compete in an ultra-triathlon should be aware that low body fat and high training volumes are highly predictive for overall race time. Little is known about the physiological characteristics of these athletes and about female ultra-triathletes. Future studies need to investigate anthropometric and training characteristics of female ultra-triathletes and what motivates women to compete in these races. Future studies need to correlate physiological characteristics such as maximum oxygen uptake (VO2max) with ultra-triathlon race performance in order to investigate whether these characteristics are also predictive for ultra-triathlon race performance.
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Affiliation(s)
- Beat Knechtle
- Institute of Primary Care, University of Zurich, Zurich, Switzerland ; Gesundheitszentrum St Gallen, St Gallen, Switzerland
| | | | - Thomas Rosemann
- Institute of Primary Care, University of Zurich, Zurich, Switzerland
| | - Michael Stiefel
- Institute of Primary Care, University of Zurich, Zurich, Switzerland
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Armstrong LE, Johnson EC, McKenzie AL, Ellis LA, Williamson KH. Ultraendurance Cycling in a Hot Environment. J Strength Cond Res 2015; 29:869-76. [DOI: 10.1519/jsc.0000000000000822] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Barrero A, Erola P, Bescós R. Energy balance of triathletes during an ultra-endurance event. Nutrients 2014; 7:209-22. [PMID: 25558906 PMCID: PMC4303834 DOI: 10.3390/nu7010209] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Accepted: 12/15/2014] [Indexed: 11/16/2022] Open
Abstract
UNLABELLED The nutritional strategy during an ultra-endurance triathlon (UET) is one of the main concerns of athletes competing in such events. The purpose of this study is to provide a proper characterization of the energy and fluid intake during real competition in male triathletes during a complete UET and to estimate the energy expenditure (EE) and the fluid balance through the race. METHODS Eleven triathletes performed a UET. All food and drinks ingested during the race were weighed and recorded in order to assess the energy intake (EI) during the race. The EE was estimated from heart rate (HR) recordings during the race, using the individual HR-oxygen uptake (Vo2) regressions developed from three incremental tests on the 50-m swimming pool, cycle ergometer, and running treadmill. Additionally, body mass (BM), total body water (TBW) and intracellular (ICW) and extracellular water (ECW) were assessed before and after the race using a multifrequency bioimpedance device (BIA). RESULTS Mean competition time and HR was 755 ± 69 min and 137 ± 6 beats/min, respectively. Mean EI was 3643 ± 1219 kcal and the estimated EE was 11,009 ± 664 kcal. Consequently, athletes showed an energy deficit of 7365 ± 1286 kcal (66.9% ± 11.7%). BM decreased significantly after the race and significant losses of TBW were found. Such losses were more related to a reduction of extracellular fluids than intracellular fluids. CONCLUSIONS Our results confirm the high energy demands of UET races, which are not compensated by nutrient and fluid intake, resulting in a large energy deficit.
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Affiliation(s)
- Anna Barrero
- National Institute of Physical Education, University of Barcelona, Barcelona 08038, Spain.
| | - Pau Erola
- Departament d'Enginyeria Informàtica i Matemàtiques, Universitat Rovira i Virgili, Tarragona 43007, Spain.
| | - Raúl Bescós
- Institute of Sport, Exercise and Active Living (ISEAL), College of Sport and Exercise Science, Victoria University, Melbourne 3011, Australia.
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Abstract
Although the sport of triathlon provides an opportunity to research the effect of multi-disciplinary exercise on health across the lifespan, much remains to be done. The literature has failed to consistently or adequately report subject age group, sex, ability level, and/or event-distance specialization. The demands of training and racing are relatively unquantified. Multiple definitions and reporting methods for injury and illness have been implemented. In general, risk factors for maladaptation have not been well-described. The data thus far collected indicate that the sport of triathlon is relatively safe for the well-prepared, well-supplied athlete. Most injuries 'causing cessation or reduction of training or seeking of medical aid' are not serious. However, as the extent to which they recur may be high and is undocumented, injury outcome is unclear. The sudden death rate for competition is 1.5 (0.9-2.5) [mostly swim-related] occurrences for every 100,000 participations. The sudden death rate is unknown for training, although stroke risk may be increased, in the long-term, in genetically susceptible athletes. During heavy training and up to 5 days post-competition, host protection against pathogens may also be compromised. The incidence of illness seems low, but its outcome is unclear. More prospective investigation of the immunological, oxidative stress-related and cardiovascular effects of triathlon training and competition is warranted. Training diaries may prove to be a promising method of monitoring negative adaptation and its potential risk factors. More longitudinal, medical-tent-based studies of the aetiology and treatment demands of race-related injury and illness are needed.
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Affiliation(s)
- Veronica Vleck
- CIPER, Faculty of Human Kinetics, University of Lisbon, Estrada da Costa, Cruz Quebrada-Dafundo, 1499-002, Portugal,
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Abstract
The objective of this article is to provide a review of the fundamental aspects of body fluid balance and the physiological consequences of water imbalances, as well as discuss considerations for the optimal composition of a fluid replacement beverage across a broad range of applications. Early pioneering research involving fluid replacement in persons suffering from diarrheal disease and in military, occupational, and athlete populations incurring exercise- and/or heat-induced sweat losses has provided much of the insight regarding basic principles on beverage palatability, voluntary fluid intake, fluid absorption, and fluid retention. We review this work and also discuss more recent advances in the understanding of fluid replacement as it applies to various populations (military, athletes, occupational, men, women, children, and older adults) and situations (pathophysiological factors, spaceflight, bed rest, long plane flights, heat stress, altitude/cold exposure, and recreational exercise). We discuss how beverage carbohydrate and electrolytes impact fluid replacement. We also discuss nutrients and compounds that are often included in fluid-replacement beverages to augment physiological functions unrelated to hydration, such as the provision of energy. The optimal composition of a fluid-replacement beverage depends upon the source of the fluid loss, whether from sweat, urine, respiration, or diarrhea/vomiting. It is also apparent that the optimal fluid-replacement beverage is one that is customized according to specific physiological needs, environmental conditions, desired benefits, and individual characteristics and taste preferences.
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Physiopathological, Epidemiological, Clinical and Therapeutic Aspects of Exercise-Associated Hyponatremia. J Clin Med 2014; 3:1258-75. [PMID: 26237602 PMCID: PMC4470181 DOI: 10.3390/jcm3041258] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Revised: 10/24/2014] [Accepted: 10/24/2014] [Indexed: 11/25/2022] Open
Abstract
Exercise-associated hyponatremia (EAH) is dilutional hyponatremia, a variant of inappropriate antidiuretic hormone secretion (SIADH), characterized by a plasma concentration of sodium lower than 135 mEq/L. The prevalence of EAH is common in endurance (<6 hours) and ultra-endurance events (>6 hours in duration), in which both athletes and medical providers need to be aware of risk factors, symptom presentation, and management. The development of EAH is a combination of excessive water intake, inadequate suppression of the secretion of the antidiuretic hormone (ADH) (due to non osmotic stimuli), long race duration, and very high or very low ambient temperatures. Additional risk factors include female gender, slower race times, and use of nonsteroidal anti-inflammatory drugs. Signs and symptoms of EAH include nausea, vomiting, confusion, headache and seizures; it may result in severe clinical conditions associated with pulmonary and cerebral edema, respiratory failure and death. A rapid diagnosis and appropriate treatment with a hypertonic saline solution is essential in the severe form to ensure a positive outcome.
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Knechtle B, Rüst CA, Rosemann T, Martin N. 33 Ironman triathlons in 33 days-a case study. SPRINGERPLUS 2014; 3:269. [PMID: 24926424 PMCID: PMC4047275 DOI: 10.1186/2193-1801-3-269] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 05/21/2014] [Indexed: 11/10/2022]
Abstract
This case report presents the performance of an athlete who completed for the first time in history the total distance of 33 Ironman triathlons within 33 consecutive days. The athlete finished the total distance of 7,458 km (i.e. 125 km swimming, 5,940 km cycling and 1,393 km running) within a total time of 410 h and a mean time of 12 h 27 min per Ironman distance. During the 33 days, the athlete became slower in swimming (r2 = 0.27, p = 0.0019), transition time 1 (r2 = 0.66, p < 0.001), and transition time 2 (r2 = 0.48, p < 0.0001). However, in cycling (r2 = 0.07, p = 0.13), running (r2 = 0.04, p = 0.25) and overall race time (r2 = 0.10, p = 0.069), the athlete was able to maintain his performance during the 33 days. The coefficients of variation (CV) for the split times in swimming, cycling, running and overall race times were very low (i.e. 2.7%, 3.2%, 4.7%, and 2.7%, respectively) whereas the CV for transition times 1 and 2 were considerably higher (i.e. 25.5% and 55.5%, respectively). During the 33 days, body mass decreased from 83.0 kg to 80.5 kg (r2 = 0.55, p < 0.0001). Plasma [Na+] remained within the reference range, creatine kinase, blood glucose and liver enzymes were minimally elevated above the reference range after four of five stages where blood analyses were performed. This case report shows that this athlete finished 33 Ironman triathlons within 33 consecutive days with minor variations over time (i.e. even pacing) in both split times and overall race times. This performance was most probably due to the high experience of the athlete, his pacing strategy and the stable environmental conditions.
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Affiliation(s)
- Beat Knechtle
- Facharzt FMH für Allgemeinmedizin, Gesundheitszentrum St. Gallen, Vadianstrasse 26, 9001 St. Gallen, Switzerland ; Institute of General Practice and for Health Services Research, University of Zurich, Zurich, Switzerland
| | - Christoph Alexander Rüst
- Institute of General Practice and for Health Services Research, University of Zurich, Zurich, Switzerland
| | - Thomas Rosemann
- Institute of General Practice and for Health Services Research, University of Zurich, Zurich, Switzerland
| | - Normand Martin
- Centre de Médecine Sportive de Laval, Laval, Québec Canada
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Perturbed energy balance and hydration status in ultra-endurance runners during a 24 h ultra-marathon. Br J Nutr 2014; 112:428-37. [PMID: 24818799 DOI: 10.1017/s0007114514000907] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The present study aimed to assess the adequacy of energy, macronutrients and water intakes of ultra-endurance runners (UER) competing in a 24 h ultra-marathon (distance range: 122-208 km). The ad libitum food and fluid intakes of the UER (n 25) were recorded throughout the competition and analysed using dietary analysis software. Body mass (BM), urinary ketone presence, plasma osmolality (POsmol) and volume change were determined at pre- and post-competition time points. Data were analysed using appropriate t tests, with significance set at P <0·05. The total energy intake and expenditure of the UER were 20 (sd 12) and 55 (sd 11) MJ, respectively (control (CON) (n 17): 12 (sd 1) and 14 (sd 5) MJ, respectively). The protein, carbohydrate and fat intakes of the UER were 1·1 (sd 0·4), 11·3 (sd 7·0) and 1·5 (sd 0·7) g/kg BM, respectively. The rate of carbohydrate intake during the competition was 37 (sd 24) g/h. The total water intake of the UER was 9·1 (sd 4·0) litres (CON: 2·1 (sd 1·0) litres), while the rate of water intake was 378 (sd 164) ml/h. Significant BM loss occurred at pre- to post-competition time points (P =0·001) in the UER (1·6 (sd 2·0) %). No significant changes in POsmol values were observed at pre- (285 (sd 11) mOsmol/kg) to post-competition (287 (sd 10) mOsmol/kg) time points in the UER and were lower than those recorded in the CON group (P <0·05). However, plasma volume (PV) increased at post-competition time points in the UER (10·2 (sd 9·7) %; P <0·001). Urinary ketones were evident in the post-competition samples of 90 % of the UER. Energy deficit was observed in all the UER, with only one UER achieving the benchmark recommendations for carbohydrate intake during endurance exercise. Despite the relatively low water intake rates recorded in the UER, hypohydration does not appear to be an issue, considering increases in PV values observed in the majority (80 %) of the UER. Population-specific dietary recommendations may be beneficial and warranted.
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Chlíbková D, Knechtle B, Rosemann T, Žákovská A, Tomášková I, Shortall M, Tomášková I. Changes in foot volume, body composition, and hydration status in male and female 24-hour ultra-mountain bikers. J Int Soc Sports Nutr 2014; 11:12. [PMID: 24661412 PMCID: PMC3994394 DOI: 10.1186/1550-2783-11-12] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2013] [Accepted: 03/20/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The effects of running and cycling on changes in hydration status and body composition during a 24-hour race have been described previously, but data for 24-hour ultra-mountain bikers are missing. The present study investigated changes in foot volume, body composition, and hydration status in male and female 24-hour ultra-mountain bikers. METHODS We compared in 49 (37 men and 12 women) 24-hour ultra-mountain bikers (ultra-MTBers) changes (Δ) in body mass (BM). Fat mass (FM), percent body fat (%BF) and skeletal muscle mass (SM) were estimated using anthropometric methods. Changes in total body water (TBW), extracellular fluid (ECF) and intracellular fluid (ICF) were determined using bioelectrical impedance and changes in foot volume using plethysmography. Haematocrit, plasma [Na+], plasma urea, plasma osmolality, urine urea, urine specific gravity and urine osmolality were measured in a subgroup of 25 ultra-MTBers (16 men and 9 women). RESULTS In male 24-hour ultra-MTBers, BM (P < 0.001), FM (P < 0.001), %BF (P < 0.001) and ECF (P < 0.05) decreased whereas SM and TBW did not change (P > 0.05). A significant correlation was found between post-race BM and post-race FM (r = 0.63, P < 0.001). In female ultra-MTBers, BM (P < 0.05), %BF (P < 0.05) and FM (P < 0.001) decreased, whereas SM, ECF and TBW remained stable (P > 0.05). Absolute ranking in the race was related to Δ%BM (P < 0.001) and Δ%FM in men (P < 0.001) and to Δ%BM (P < 0.05) in women. In male ultra-MTBers, increased post-race plasma urea (P < 0.001) was negatively related to absolute ranking in the race, Δ%BM, post-race FM and Δ%ECF (P < 0.05). Foot volume remained stable in both sexes (P > 0.05). CONCLUSIONS Male and female 24-hour ultra-MTBers experienced a significant loss in BM and FM, whereas SM remained stable. Body weight changes and increases in plasma urea do not reflect a change in body hydration status. No oedema of the lower limbs occurred.
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Affiliation(s)
- Daniela Chlíbková
- Centre of Sports Activities, Brno University of Technology, Brno, Czech Republic
| | - Beat Knechtle
- Institute of General Practise and for Health Services Research, University of Zurich, Zurich, Switzerland
| | - Thomas Rosemann
- Institute of General Practise and for Health Services Research, University of Zurich, Zurich, Switzerland
| | - Alena Žákovská
- Institute of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Ivana Tomášková
- Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, Prague, Czech Republic
| | | | - Iva Tomášková
- SurGal clinic s.r.o., Center for Sports Medicine, Brno, Czech Republic
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