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Knechtle B, Weiss K, Valero D, Villiger E, Nikolaidis PT, Andrade MS, Scheer V, Cuk I, Gajda R, Thuany M. Using machine learning to determine the nationalities of the fastest 100-mile ultra-marathoners and identify top racing events. PLoS One 2024; 19:e0303960. [PMID: 39172797 PMCID: PMC11340887 DOI: 10.1371/journal.pone.0303960] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Accepted: 05/04/2024] [Indexed: 08/24/2024] Open
Abstract
The present study intended to determine the nationality of the fastest 100-mile ultra-marathoners and the country/events where the fastest 100-mile races are held. A machine learning model based on the XG Boost algorithm was built to predict the running speed from the athlete's age (Age group), gender (Gender), country of origin (Athlete country) and where the race occurred (Event country). Model explainability tools were then used to investigate how each independent variable influenced the predicted running speed. A total of 172,110 race records from 65,392 unique runners from 68 different countries participating in races held in 44 different countries were used for analyses. The model rates Event country (0.53) as the most important predictor (based on data entropy reduction), followed by Athlete country (0.21), Age group (0.14), and Gender (0.13). In terms of participation, the United States leads by far, followed by Great Britain, Canada, South Africa, and Japan, in both athlete and event counts. The fastest 100-mile races are held in Romania, Israel, Switzerland, Finland, Russia, the Netherlands, France, Denmark, Czechia, and Taiwan. The fastest athletes come mostly from Eastern European countries (Lithuania, Latvia, Ukraine, Finland, Russia, Hungary, Slovakia) and also Israel. In contrast, the slowest athletes come from Asian countries like China, Thailand, Vietnam, Indonesia, Malaysia, and Brunei. The difference among male and female predictions is relatively small at about 0.25 km/h. The fastest age group is 25-29 years, but the average speeds of groups 20-24 and 30-34 years are close. Participation, however, peaks for the age group 40-44 years. The model predicts the event location (country of event) as the most important predictor for a fast 100-mile race time. The fastest race courses were occurred in Romania, Israel, Switzerland, Finland, Russia, the Netherlands, France, Denmark, Czechia, and Taiwan. Athletes and coaches can use these findings for their race preparation to find the most appropriate racecourse for a fast 100-mile race time.
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Affiliation(s)
- Beat Knechtle
- Medbase St. Gallen Am Vadianplatz, St. Gallen, Switzerland
- Institute of Primary Care, University of Zurich, Zurich, Switzerland
| | - Katja Weiss
- Institute of Primary Care, University of Zurich, Zurich, Switzerland
| | - David Valero
- Ultra Sports Science Foundation, Pierre-Benite, France
| | - Elias Villiger
- Institute of Primary Care, University of Zurich, Zurich, Switzerland
| | | | | | - Volker Scheer
- Ultra Sports Science Foundation, Pierre-Benite, France
| | - Ivan Cuk
- Faculty of Sport and Physical Education, University of Belgrade, Belgrade, Serbia
| | - Robert Gajda
- Center for Sports Cardiology at the Gajda-Med Medical Center in Pułtusk, Pułtusk, Poland
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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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Perschinka F, Köglberger P, Klein SJ, Joannidis M. [Hyponatremia : Etiology, diagnosis and acute therapy]. Med Klin Intensivmed Notfmed 2023; 118:505-517. [PMID: 37646802 PMCID: PMC10501960 DOI: 10.1007/s00063-023-01049-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Revised: 05/09/2023] [Accepted: 05/15/2023] [Indexed: 09/01/2023]
Abstract
Hyponatremia is one of the most common electrolyte disorders in emergency departments and hospitalized patients. Serum sodium concentration is controlled by osmoregulation and volume regulation. Both pathways are regulated via the release of antidiuretic hormone (ADH). Syndrome of inappropriate release of ADH (SIADH) may be caused by neoplasms or pneumonia but may also be triggered by drug use or drug abuse. Excessive fluid intake may also result in a decrease in serum sodium concentration. Rapid alteration in serum sodium concentration leads to cell swelling or cell shrinkage, which primarily causes neurological symptoms. The dynamics of development of hyponatremia and its duration are crucial. In addition to blood testing, a clinical examination and urine analysis are essential in the differential diagnosis of hyponatremia.
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Affiliation(s)
- Fabian Perschinka
- Gemeinsame Einrichtung Internistische Intensiv- und Notfallmedizin, Department für Innere Medizin, Medizinische Universität Innsbruck, Anichstraße 35, 6020, Innsbruck, Österreich
| | - Paul Köglberger
- Gemeinsame Einrichtung Internistische Intensiv- und Notfallmedizin, Department für Innere Medizin, Medizinische Universität Innsbruck, Anichstraße 35, 6020, Innsbruck, Österreich
- Institut für Anästhesiologie und Intensivmedizin, Klinikum Wels, Grieskirchnerstraße 42, 4600, Wels, Österreich
| | - Sebastian J Klein
- Gemeinsame Einrichtung Internistische Intensiv- und Notfallmedizin, Department für Innere Medizin, Medizinische Universität Innsbruck, Anichstraße 35, 6020, Innsbruck, Österreich
| | - Michael Joannidis
- Gemeinsame Einrichtung Internistische Intensiv- und Notfallmedizin, Department für Innere Medizin, Medizinische Universität Innsbruck, Anichstraße 35, 6020, Innsbruck, Österreich.
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Exercise-Associated Hyponatremia in Marathon Runners. J Clin Med 2022; 11:jcm11226775. [PMID: 36431252 PMCID: PMC9699060 DOI: 10.3390/jcm11226775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Revised: 11/01/2022] [Accepted: 11/05/2022] [Indexed: 11/19/2022] Open
Abstract
Exercise-associated hyponatremia (EAH) was first described as water intoxication by Noakes et al. in 1985 and has become an important topic linked to several pathological conditions. However, despite progressive research, neurological disorders and even deaths due to hyponatremic encephalopathy continue to occur. Therefore, and due to the growing popularity of exercise-associated hyponatremia, this topic is of great importance for marathon runners and all professionals involved in runners' training (e.g., coaches, medical staff, nutritionists, and trainers). The present narrative review sought to evaluate the prevalence of EAH among marathon runners and to identify associated etiological and risk factors. Furthermore, the aim was to derive preventive and therapeutic action plans for marathon runners based on current evidence. The search was conducted on PubMed, Scopus and Google Scholar using a predefined search algorithm by aggregating multiple terms (marathon run; exercise; sport; EAH; electrolyte disorder; fluid balance; dehydration; sodium concentration; hyponatremia). By this criterion, 135 articles were considered for the present study. Our results revealed that a complex interaction of different factors could cause EAH, which can be differentiated into event-related (high temperatures) and person-related (female sex) risk factors. There is variation in the reported prevalence of EAH, and two major studies indicated an incidence ranging from 7 to 15% for symptomatic and asymptomatic EAH. Athletes and coaches must be aware of EAH and its related problems and take appropriate measures for both training and competition. Coaches need to educate their athletes about the early symptoms of EAH to intervene at the earliest possible stage. In addition, individual hydration strategies need to be developed for the daily training routine, ideally in regard to sweat rate and salt losses via sweat. Future studies need to investigate the correlation between the risk factors of EAH and specific subgroups of marathon runners.
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Hydration Strategies for Physical Activity and Endurance Events at High (>2500 m) Altitude: A Practical Management Article. Clin J Sport Med 2022; 32:407-413. [PMID: 33852437 DOI: 10.1097/jsm.0000000000000919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 01/11/2021] [Indexed: 02/02/2023]
Abstract
A growing number of adventurous athletes are seeking new challenges through endurance events or physical activities held at high altitude (>2500 m). This coincides with a significant increase in the numbers of trekkers who ascend into the world's mountains. Altitude itself influences and complicates the athlete's effective and safe hydration. This article considers the physiology of adaptation to altitude and the effects on hydration at altitude compared with sea level, reviews the "ad libitum versus programmed hydration" controversy in conventional endurance event hydration, examines the evidence for extrapolation of sea level hydration strategies to the high-altitude environment, and synthesizes these disparate factors into a set of practical recommendations for hydration management during high-altitude physical activity. The guidelines will be relevant to participants of physical activity at altitude and health care staff who may care for them in the preparation or performance phases of their adventure.
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Zhang J, Zhang N, Du S, Liu S, Ma G. Acute Water Supplementation Improved the Body Composition of Young Female Adults After Water Restriction of 12 h in Baoding, China: A Randomized Controlled Trial (RCT). Front Nutr 2022; 9:880630. [PMID: 35795583 PMCID: PMC9251362 DOI: 10.3389/fnut.2022.880630] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 04/27/2022] [Indexed: 12/15/2022] Open
Abstract
Insufficient intake of water may influence the balance of water in the human body. In this study, we explore the impacts of water supplementation on body composition indices among young adults after 12 h of water restriction, with the aim to determine the optimum volume of water for improving body water composition. A randomized controlled trial study was conducted among 64 young men and women in Baoding, China. After fasting overnight for 12 h, anthropometric measurements and urine and blood samples were collected as a baseline test at 8:00 a.m. of Day 2. Body composition was determined by measuring the ECW (extracellular water), ICW (intracellular water), and TBW (total body water) through bioelectrical impedance analysis (BIA). The participants were randomly divided into four groups, including water supplementation (WS) groups 1, 2, and 3, with 500, 200, and 100 mL of water, respectively, and a no water supplementation (NW) group. After 90 min, they were reassessed in a rehydration test (at 10:00 a.m. of Day 2). Repeated measurement ANOVA was used to assess the impact of water supplementation on body composition. Comparing the baseline and rehydration tests, interactions between time and volume were not significant among the men (all p > 0.05). Among women, a significant interaction was only found in ECW (p = 0.043), with TBW tending toward being significant (p = 0.055). Comparing the baseline and rehydration tests, the ECW in WS group 1, WS group 3, and the NW group all decreased (p = 0.028, p = 0.001, and p = 0.029), with reductions of 0.1, 0.3, and 0.2 kg, respectively; however, no significant decrease was observed in WS group 2 (p = 0.329). Furthermore, comparing the WS groups with the NW group in the rehydration test, the differences were not significant (p = 1.000, p = 1.000, and p = 0.288, respectively). Between men and women within groups, all of the body composition indices differed significantly, both at baseline and rehydration tests (all p < 0.05). Water supplementation led to changes in the distribution of the water content in young female adults in this study-but not men-after 12 h of water restriction, with no decrease in ECW. Finally, we found that 200 mL was the minimum volume capable of improving the water content distribution in participants in this study. Trial Registration [www.chictr.org.cn], identifier [ChiCTR-IOR-17011568].
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Affiliation(s)
- Jianfen Zhang
- Department of Nutrition and Food Hygiene, School of Public Health, Peking University, Beijing, China
- Laboratory of Toxicological Research and Risk Assessment for Food Safety, Peking University, Beijing, China
| | - Na Zhang
- Department of Nutrition and Food Hygiene, School of Public Health, Peking University, Beijing, China
- Laboratory of Toxicological Research and Risk Assessment for Food Safety, Peking University, Beijing, China
| | | | - Shufang Liu
- School of Public Health, Health Science Center, Hebei University, Baoding, China
| | - Guansheng Ma
- Department of Nutrition and Food Hygiene, School of Public Health, Peking University, Beijing, China
- Laboratory of Toxicological Research and Risk Assessment for Food Safety, Peking University, Beijing, China
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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: 3] [Impact Index Per Article: 1.5] [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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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: 4] [Impact Index Per Article: 1.3] [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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Huang MK, Chang KS, Kao WF, Li LH, How CK, Wang SH, Lin YK, Hwang YS, Chien DK, Chiu YH. Visual hallucinations in 246-km mountain ultra-marathoners: An observational study. CHINESE J PHYSIOL 2021; 64:225-231. [PMID: 34708714 DOI: 10.4103/cjp.cjp_57_21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Ultra-marathons are typically held over harsh terrains such as mountains, deserts, or other wilderness, and place severe demands on the physical and psychological capabilities of participants. Adventure-race competitors commonly report hallucinations. The goal of this study was to gain insight into visual hallucinations (VHs) during a mountain ultra-marathon. Thirty-one Taiwanese runners who participated in the 2018 Run Across Taiwan Ultra-Marathon, which spans 246 km with an altitude difference of 3266 m and an overall cut-off time of 44 h, volunteered for this study. Self-reported questionnaires on sleep duration, hallucinatory experiences, clinical symptoms of cold- and heat-related illnesses, and the 2018 Lake Louise Acute Mountain Sickness (AMS) Score were recorded prerace, during the summit, immediately postrace, and 3-days postrace. Hematological samples were collected 1 week before, immediately after, and 3 days after the race. Eight ultra-marathoners (six males and two females; seven finishers and one withdrawer) were recruited. Three out of eight (37.5%) subjects (two males and one female) reported experiencing VHs during the last 60 km. Three out of five (60%) lower-ranked subjects experienced VHs. All eight runners slept for <30 min during the race. None of the runners presented with headache either during or after the race to meet the criteria for AMS. None of the runners suffered an abnormal thermoregulatory response or a hypoglycemic episode throughout the ultra-marathon. The changes in blood osmolality immediately postrace were subclinical, despite being statistically significant. Among the three runners with VHs, none presented with severe dehydration or dysnatremia immediately postrace. High-altitude exposure, hyper/hypothermia, dehydration, dysnatermia, or hypoglycemia did not seem to contribute to hallucination onset in our subjects during the event. VHs of ultra-marathoners may be associated with excessive physical exertion and sleep deprivation.
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Affiliation(s)
- Ming-Kun Huang
- Department of Emergency Medicine, Mackay Memorial Hospital; Department of Electronic Engineering, National Taipei University of Technology, Taipei; Department of Medicine, Mackay Medical College, New Taipei City, Taiwan
| | - Kuo-Song Chang
- Department of Emergency Medicine, Mackay Memorial Hospital; Department of Medicine, Mackay Medical College, New Taipei City, Taiwan
| | - Wei-Fong Kao
- Department of Emergency and Critical Care Medicine, Taipei Medical University Hospital; Department of Emergency, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Li-Hua Li
- Department of Pathology and Laboratory Medicine, Taipei Veterans General Hospital; Program of Medical Biotechnology, Taipei Medical University, Taipei, Taiwan
| | - Chorng-Kuang How
- Department of Emergency Medicine, Taipei Veterans General Hospital; Department of Emergency Medicine, School of Medicine, National Yang Ming Chiao Tung University, Taipei; Department of Emergency Medicine, Kinmen Hospital, Ministry of Health and Welfare, Kinmen, Taiwan
| | | | - Yen-Kuang Lin
- Graduate Institute of Athletics and Coaching Science, National Taiwan Sport University, Taoyuan, Taiwan
| | - Yuh-Shyan Hwang
- Department of Electronic Engineering, National Taipei University of Technology, Taipei, Taiwan
| | - Ding-Kuo Chien
- Department of Emergency Medicine, Mackay Memorial Hospital, Taipei; Department of Medicine, Mackay Medical College, New Taipei City, Taiwan
| | - Yu-Hui Chiu
- Department of Emergency Medicine, Mackay Memorial Hospital; Department of Medicine, Mackay Medical College, New Taipei City; Department of Emergency, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
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Périard JD, Eijsvogels TMH, Daanen HAM. Exercise under heat stress: thermoregulation, hydration, performance implications, and mitigation strategies. Physiol Rev 2021; 101:1873-1979. [PMID: 33829868 DOI: 10.1152/physrev.00038.2020] [Citation(s) in RCA: 151] [Impact Index Per Article: 50.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
A rise in body core temperature and loss of body water via sweating are natural consequences of prolonged exercise in the heat. This review provides a comprehensive and integrative overview of how the human body responds to exercise under heat stress and the countermeasures that can be adopted to enhance aerobic performance under such environmental conditions. The fundamental concepts and physiological processes associated with thermoregulation and fluid balance are initially described, followed by a summary of methods to determine thermal strain and hydration status. An outline is provided on how exercise-heat stress disrupts these homeostatic processes, leading to hyperthermia, hypohydration, sodium disturbances, and in some cases exertional heat illness. The impact of heat stress on human performance is also examined, including the underlying physiological mechanisms that mediate the impairment of exercise performance. Similarly, the influence of hydration status on performance in the heat and how systemic and peripheral hemodynamic adjustments contribute to fatigue development is elucidated. This review also discusses strategies to mitigate the effects of hyperthermia and hypohydration on exercise performance in the heat by examining the benefits of heat acclimation, cooling strategies, and hyperhydration. Finally, contemporary controversies are summarized and future research directions are provided.
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Affiliation(s)
- Julien D Périard
- University of Canberra Research Institute for Sport and Exercise, Bruce, Australia
| | - Thijs M H Eijsvogels
- Department of Physiology, Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Hein A M Daanen
- Department of Human Movement Sciences, Faculty of Behavioural and Movement Sciences, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
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13
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Zhang J, Zhang N, Du S, Liu S, Ma G. Effects of Water Restriction and Water Replenishment on the Content of Body Water with Bioelectrical Impedance among Young Adults in Baoding, China: A Randomized Controlled Trial (RCT). Nutrients 2021; 13:553. [PMID: 33567589 PMCID: PMC7915432 DOI: 10.3390/nu13020553] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 01/31/2021] [Accepted: 02/05/2021] [Indexed: 02/02/2023] Open
Abstract
Insufficient water intake may affect body composition. The purpose of this research was to explore the effects of water restriction and replenishment on body composition and to evaluate the optimum amount of water that improves body composition. A total of 76 young adults aged 18-23 years old (40 males and 36 females) in Baoding, China, were recruited in this randomized controlled trial, with a 100% completion rate. After fasting overnight for 12 h, at 8:00 a.m. of day 2, a baseline test, including anthropometric indices and collection of urine and blood samples, was explored. Participants were then subjected to water restriction for 24 h, and three meals with ≤75% water content were provided. At 8:00 AM of day 3, the same indices were determined as a dehydration test. Then, participants were randomly assigned into four groups: three water replenishment groups (WR groups 1, 2, and 3 given 1000, 500, and 200 mL of purified water, respectively) and one non-replenishment group (NR group, with no water). After 90 min, the same measurements were performed as a rehydration test. Compared with the baseline test, during the dehydration test, the intracellular water to total body water ratio (ICW/TBW) increased; and extracellular water (ECW), ECW/TBW (extracellular water to total body water ratio), and TBW decreased (all p < 0.05). For males, significant differences were found in ECW, ECW/ICW (extracellular water to intracellular water ratio), ICW/TBW, and ECW/TBW (all p < 0.05); for females, significant reductions were found in ICW, ECW, TBW, ECW/ICW, ICW/TBW, and ECW/TBW (all p < 0.05). Furthermore, significant differences were found in ICW, ECW, ICW/TBW, ECW/TBW, ECW/ICW, TBW, and TBW/BW between males and females during the baseline and dehydration test (all p < 0.05). Comparing the dehydration test with the rehydration test, there were significant interactions between time × volume in ICW and TBW (F = 3.002, p = 0.036; F = 2.907, p = 0.040); in males, these were only found in ICW (F = 3.061, p = 0.040); in females, they were found in ICW and TBW (F = 3.002, p = 0.036; F = 2.907, p = 0.040). The ICW levels in WR groups 1 and 2 were all higher than in the NR group (all p < 0.05); the TBW was higher in WR group 1 than in the NR group (p < 0.05). No significant differences were found between WR groups 1 and 2, either in males or in females (all p > 0.05). In the rehydration test, significant differences in body composition were found between males and females among the four groups (all p < 0.05). Water restriction had adverse effects on body composition, and females were more susceptible to water restriction than males. Water replenishment improved the water content of body composition, alleviating the adverse effects of water restriction on ICW and TBW. After water restriction for 36 h, the optimum volume of water to improve body composition among young male adults was 1000 mL, but this was not the case for females.
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Affiliation(s)
- Jianfen Zhang
- Department of Nutrition and Food Hygiene, School of Public Health, Peking University, 38 Xue Yuan Road, Haidian District, Beijing 100191, China; (J.Z.); (N.Z.)
- Laboratory of Toxicological Research and Risk Assessment for Food Safety, Peking University, 38 Xue Yuan Road, Haidian District, Beijing 100191, China
| | - Na Zhang
- Department of Nutrition and Food Hygiene, School of Public Health, Peking University, 38 Xue Yuan Road, Haidian District, Beijing 100191, China; (J.Z.); (N.Z.)
- Laboratory of Toxicological Research and Risk Assessment for Food Safety, Peking University, 38 Xue Yuan Road, Haidian District, Beijing 100191, China
| | - Songming Du
- Chinese Nutrition Society, Room 1405, Beijing Broadcasting Building, No. 14 Jianguomenrai Street, Chaoyang District, Beijing 100191, China;
| | - Shufang Liu
- School of Public Health, Hebei University Health Science Center, 342 Yuhua Road, Lianchi District, Baoding 071000, China;
| | - Guansheng Ma
- Department of Nutrition and Food Hygiene, School of Public Health, Peking University, 38 Xue Yuan Road, Haidian District, Beijing 100191, China; (J.Z.); (N.Z.)
- Laboratory of Toxicological Research and Risk Assessment for Food Safety, Peking University, 38 Xue Yuan Road, Haidian District, Beijing 100191, China
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Bouscaren N, Millet GY, Racinais S. Heat Stress Challenges in Marathon vs. Ultra-Endurance Running. Front Sports Act Living 2019; 1:59. [PMID: 33344982 PMCID: PMC7739648 DOI: 10.3389/fspor.2019.00059] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 10/21/2019] [Indexed: 11/13/2022] Open
Abstract
Several studies have investigated the effect of hot and humid ambient conditions on running exercise up to the marathon. However, studies on exercise longer than marathon are sparse. Events exceeding 6 h can be defined as ultra-endurance and have variable characteristics (e.g., distance, elevation profile, technical difficulty, altitude, night running) making hazardous the transposition of the current knowledge obtained in marathon to ultra-endurance running. Thus, the aim of this manuscript was to discuss the potential differences between marathon and ultra-endurance running in terms of heat stress challenges. The high running intensity (especially for the fastest runners), the urban context with high albedo effect materials, and the hot self-generated microclimate in mass-participation events (especially for the average to slow runners) are specific risk factors associated with marathon running in hot environments. Uphill running/walking (sometimes with poles), exotic destination with long-haul travel, desert environment and the necessity to sustain thermoregulatory and sweating responses for several days are risk factors more specific to ultra-endurance running. These differences call for specific research on the effect of hot ambient conditions in ultra-endurance disciplines to create appropriate recommendations.
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Affiliation(s)
| | - Guillaume Y. Millet
- Univ Lyon, UJM-Saint-Étienne, Inter-University Laboratory of Human Movement Biology, EA 7424, Saint-Étienne, France
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Seal AD, Anastasiou CA, Skenderi KP, Echegaray M, Yiannakouris N, Tsekouras YE, Matalas AL, Yannakoulia M, Pechlivani F, Kavouras SA. Incidence of Hyponatremia During a Continuous 246-km Ultramarathon Running Race. Front Nutr 2019; 6:161. [PMID: 31681787 PMCID: PMC6798088 DOI: 10.3389/fnut.2019.00161] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 09/26/2019] [Indexed: 01/27/2023] Open
Abstract
Purpose: The purpose of this observational study was to examine the incidence of exercise-associated hyponatremia (EAH) in a 246-km continuous ultra-marathon. Methods: Over 2 years, 63 male finishers of the annual Spartathlon ultra-marathon foot race from Athens to Sparta, Greece were included in the data analysis. A blood sample was drawn from an antecubital vein the day before the race as well as within 15 min post-race and analyzed for sodium concentration. During the second year of data collection, blood was also drawn at the 93-km checkpoint (n = 29). Height and weight were measured pre and post-race. Results: Mean race time of all subjects was 33 ± 3 h with a range of 23.5 and 36.0 h. Of the 63 finishers recruited, nine began the race with values indicative of mild hyponatremia. Seven runners were classified as hyponatremic at the 93-km checkpoint, three of whom had sodium levels of severe hyponatremia. After the race, 41 total finishers (65%) developed either mild (n = 27, 43%) or severe hyponatremia (n = 14, 22%). Mean change in bodyweight percentage and serum sodium from pre-race to post-race was −3.6 ± 2.7% (−2.5 ± 1.9 kg) and −6.6 ± 5.6 mmol·L−1, respectively. Pre-race serum sodium level was not a significant predictor of post-race serum sodium levels (β = 0.08, R2 = 0.07, P = 0.698), however, there was a significant negative association between change in bodyweight percentage and post-race serum sodium concentration (β = −0.79, R2 = 0.29, P = 0.011). Conclusion: The incidence of EAH of 52 and 65%, when excluding or including these individuals with pre-race hyponatremia, was the highest reported in current literature.
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Affiliation(s)
- Adam D Seal
- Hydration Science Lab, Arizona State University, Phoenix, AZ, United States
| | | | | | - Marcos Echegaray
- Department of Biology, University of Puerto Rico at Cayey, Cayey, Puerto Rico
| | - Nikos Yiannakouris
- Department of Nutrition and Dietetics, Harokopio University, Athens, Greece
| | | | - Antonia L Matalas
- Department of Nutrition and Dietetics, Harokopio University, Athens, Greece
| | - Mary Yannakoulia
- Department of Nutrition and Dietetics, Harokopio University, Athens, Greece
| | - Fani Pechlivani
- Technological Educational Institution of Athens, Athens, Greece
| | - Stavros A Kavouras
- Hydration Science Lab, Arizona State University, Phoenix, AZ, United States
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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. MEDICINA (KAUNAS, LITHUANIA) 2019; 55:E537. [PMID: 31455034 PMCID: PMC6780610 DOI: 10.3390/medicina55090537] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [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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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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18
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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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19
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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: 38] [Impact Index Per Article: 6.3] [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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20
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Knechtle B, Nikolaidis PT. Physiology and Pathophysiology in Ultra-Marathon Running. Front Physiol 2018; 9:634. [PMID: 29910741 PMCID: PMC5992463 DOI: 10.3389/fphys.2018.00634] [Citation(s) in RCA: 152] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 05/11/2018] [Indexed: 12/31/2022] Open
Abstract
In this overview, we summarize the findings of the literature with regards to physiology and pathophysiology of ultra-marathon running. The number of ultra-marathon races and the number of official finishers considerably increased in the last decades especially due to the increased number of female and age-group runners. A typical ultra-marathoner is male, married, well-educated, and ~45 years old. Female ultra-marathoners account for ~20% of the total number of finishers. Ultra-marathoners are older and have a larger weekly training volume, but run more slowly during training compared to marathoners. Previous experience (e.g., number of finishes in ultra-marathon races and personal best marathon time) is the most important predictor variable for a successful ultra-marathon performance followed by specific anthropometric (e.g., low body mass index, BMI, and low body fat) and training (e.g., high volume and running speed during training) characteristics. Women are slower than men, but the sex difference in performance decreased in recent years to ~10–20% depending upon the length of the ultra-marathon. The fastest ultra-marathon race times are generally achieved at the age of 35–45 years or older for both women and men, and the age of peak performance increases with increasing race distance or duration. An ultra-marathon leads to an energy deficit resulting in a reduction of both body fat and skeletal muscle mass. An ultra-marathon in combination with other risk factors, such as extreme weather conditions (either heat or cold) or the country where the race is held, can lead to exercise-associated hyponatremia. An ultra-marathon can also lead to changes in biomarkers indicating a pathological process in specific organs or organ systems such as skeletal muscles, heart, liver, kidney, immune and endocrine system. These changes are usually temporary, depending on intensity and duration of the performance, and usually normalize after the race. In longer ultra-marathons, ~50–60% of the participants experience musculoskeletal problems. The most common injuries in ultra-marathoners involve the lower limb, such as the ankle and the knee. An ultra-marathon can lead to an increase in creatine-kinase to values of 100,000–200,000 U/l depending upon the fitness level of the athlete and the length of the race. Furthermore, an ultra-marathon can lead to changes in the heart as shown by changes in cardiac biomarkers, electro- and echocardiography. Ultra-marathoners often suffer from digestive problems and gastrointestinal bleeding after an ultra-marathon is not uncommon. Liver enzymes can also considerably increase during an ultra-marathon. An ultra-marathon often leads to a temporary reduction in renal function. Ultra-marathoners often suffer from upper respiratory infections after an ultra-marathon. Considering the increased number of participants in ultra-marathons, the findings of the present review would have practical applications for a large number of sports scientists and sports medicine practitioners working in this field.
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Affiliation(s)
- Beat Knechtle
- Institute of Primary Care, University of Zurich, Zurich, Switzerland
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21
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Hoffman MD, Joslin J, Rogers IR. Management of Suspected Fluid Balance Issues in Participants of Wilderness Endurance Events. Curr Sports Med Rep 2017; 16:98-102. [PMID: 28282356 DOI: 10.1249/jsr.0000000000000344] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Dehydration and exercise-associated hyponatremia (EAH) are both relatively common conditions during wilderness endurance events. Whereas dehydration is treated with fluids, EAH is appropriately managed with fluid restriction and a sodium bolus but can worsen with isotonic or hypotonic fluids. Therefore, caution is recommended in the provision of postevent rehydration in environments where EAH is a potential consideration because accurate field assessment of hydration status can be challenging, and measurement of blood sodium concentration is rarely possible in the wilderness. Dehydration management with oral rehydration is generally adequate and preferred to intravenous rehydration, which should be reserved for athletes with sustained orthostasis or inability to tolerate oral fluid ingestion after some rest. In situations where intravenous hydration is initiated without known blood sodium concentration or hydration status, an intravenous concentrated sodium solution should be available in the event of acute neurological deterioration consistent with the development of EAH encephalopathy.
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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; 2Department of Emergency Medicine, State University of New York Upstate Medical University, Syracuse, NY; 3St. John of God Murdoch Hospital & University of Notre Dame, Murdoch, WA, Australia
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Chlíbková D, Nikolaidis PT, Rosemann T, Knechtle B, Bednář J. Reported Hydration Beliefs and Behaviors without Effect on Plasma Sodium in Endurance Athletes. Front Physiol 2017; 8:259. [PMID: 28512433 PMCID: PMC5411442 DOI: 10.3389/fphys.2017.00259] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 04/10/2017] [Indexed: 11/13/2022] Open
Abstract
Purpose: Little information is available on the association of hydration beliefs and behaviors in endurance athletes and exercise-associated hyponatremia (EAH). The aim of the present study was to determine hydration beliefs and behaviors in endurance athletes. Method: A 100 and 38 recreational athletes [107 mountain bikers (MTBers) and 31 runners] competing in seven different endurance and ultra-endurance races completed pre- and post-race questionnaires, and a subgroup of 113 (82%) participants (82 MTBers and 31 runners) also provided their blood samples. Result: More than half of the participants had some pre-race (59%), mid-race (58%), and post-race (55%) drinking plan. However, the participants simultaneously reported that temperature (66%), thirst (52%), and plan (37%) affected their drinking behavior during the race. More experienced (years of active sport: p = 0.002; number of completed races: p < 0.026) and trained (p = 0.024) athletes with better race performance (p = 0.026) showed a more profound knowledge of EAH, nevertheless, this did not influence their planned hydration, reported fluid intake, or post-race plasma sodium. Thirteen (12%) hyponatremic participants did not differ in their hydration beliefs, race behaviors, or reported fluid intake from those without post-race EAH. Compared to MTBers, runners more often reported knowledge of the volumes of drinks offered at fluid stations (p < 0.001) and information on how much to drink pre-race (p < 0.001), yet this was not associated with having a drinking plan (p > 0.05). MTBers with hydration information planned more than other MTBers (p = 0.004). In comparison with runners, more MTBers reported riding with their own fluids (p < 0.001) and planning to drink at fluid stations (p = 0.003). On the whole, hydration information was positively associated with hydration planning (n = 138) (p = 0.003); nevertheless, the actual reported fluid intake did not differ between the group with and without hydration information, or with and without a pre-race drinking plan (p > 0.05). Conclusion: In summary, hydration beliefs and behaviors in the endurance athletes do not appear to affect the development of asymptomatic EAH.
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Affiliation(s)
- Daniela Chlíbková
- Centre of Sports Activities, Brno University of TechnologyBrno, Czechia
| | | | - Thomas Rosemann
- Institute of Primary Care, University of ZurichZurich, Switzerland
| | - Beat Knechtle
- Institute of Primary Care, University of ZurichZurich, Switzerland.,Gesundheitszentrum St. GallenSt. Gallen, Switzerland
| | - Josef Bednář
- Faculty of Mechanical Engineering, Brno University of TechnologyBrno, Czechia
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Abstract
Ultramarathon runners are a relatively small and unique group of distance runners with somewhat different medical issues than other distance runners. This article outlines some of those differences so that clinicians caring for these runners in the clinic or at competitions might be better prepared.
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Cutrufello PT, Dixon CB, Zavorsky GS. Hydration assessment among marathoners using urine specific gravity and bioelectrical impedance analysis. Res Sports Med 2016; 24:234-42. [PMID: 27373703 DOI: 10.1080/15438627.2016.1202831] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The present study examined the relationship between urine specific gravity (Usg), body mass (BM) and bioelectrical impedance determined variables [total body water (TBW), per cent TBW and impedance values] before and after a marathon (n = 25 men; 10 women). A significant reduction in BM (pre: 71.2 ± 12.4 kg; post: 69.6 ± 12.0 kg; p < 0.001) and an increase in Usg (pre: 1.009 ± 0.007; post: 1.018 ± 0.009; p < 0.001) was observed post-race. TBW was not significantly decreased (pre: 42.7 ± 8.0 kg; post: 42.4 ± 7.7 kg) while per cent TBW significantly increased post-race (pre: 60.0 ± 3.9%; post: 60.8 ± 3.8%; p < 0.001). Impedance values were significantly greater post-race (pre: 3288 ± 482; post: 3416 ± 492 Ω; p < 0.001). There was no correlation between the change in Usg and the change in BM or any of the bioelectrical impedance determined variables. On average, BM, Usg and impedance values appear to express changes in hydration; however, the observed changes among these variables for a given individual appear to be inconsistent with one another.
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Affiliation(s)
- Paul T Cutrufello
- a Exercise Science and Sport , The University of Scranton , Scranton , PA , USA
| | - Curt B Dixon
- b Health Sciences Dept , Lock Haven University , Lock Haven , PA , USA
| | - Gerald S Zavorsky
- c Department of Health and Sports Sciences , University of Louisville , Louisville , KY , USA
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Larson HH, Khalili-Borna D, Uzosike E, Sugiyama D. Medical Coverage of Ultramarathons and Its Unique Challenges. Curr Sports Med Rep 2016; 15:154-60. [PMID: 27172078 DOI: 10.1249/jsr.0000000000000267] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Medical coverage of ultramarathons must take into account unique logistical, environmental, and psychological components in addition to the medical conditions that may arise. Each ultramarathon is unique and carries with it distinct specific challenges with regard to appropriate planning and organizing. The medical issues encountered with ultramarathons can overlap with those seen in other endurance events, but the extreme and protracted nature of ultramarathons also lends itself to various other medical challenges not frequently encountered in other aspects of sports medicine. This article gives an overview of logistical considerations that go into the medical planning, as well as information regarding diagnosis and acute management of some of the most common and most important conditions that one might encounter when covering an ultramarathon.
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Special Considerations in Medical Screening for Participants in Remote Endurance Events. Sports Med 2016; 45:1121-31. [PMID: 26002285 DOI: 10.1007/s40279-015-0342-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
As participation at remote endurance events increases, so does the need to screen participants for potentially problematic medical conditions, but this process has been ill-defined to date. This article aims to outline a general approach to screening and discusses common or important medical conditions that may need consideration in the screening process. Medical conditions that are considered low risk may translate to high-risk conditions in the setting of a remote and austere location. Medical directors of remote endurance events should have a familiarity with assessing risks and applying informed consent principles to participation. While there are no specific standards on medical disqualification from an event based on medical history alone, several systematic considerations should be made that allow for an assessment of risk to an individual for a specific event. The medical director and event director, in discussion with the athlete and treating clinician when appropriate, should come to a consensus on participation when high-risk medical conditions become apparent during the screening process. Both modifications and accommodations to participation may be used to mitigate both clinical and medicolegal risk and allow for participation.
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Cairns RS, Hew-Butler T. Proof of concept: hypovolemic hyponatremia may precede and augment creatine kinase elevations during an ultramarathon. Eur J Appl Physiol 2016; 116:647-55. [PMID: 26747653 DOI: 10.1007/s00421-015-3324-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 12/20/2015] [Indexed: 12/20/2022]
Abstract
PURPOSE It is not known if exercise-associated hyponatremia (EAH) is a cause or consequence of exertional rhabdomyolysis (ER).We hypothesized that osmotic stress (EAH) coupled with mechanical stress (running) potentiated muscle cell breakdown (ER). This concept would be supported if a nadir in serum sodium concentration ([Na(+)]) temporally preceded peak creatine kinase levels (CK) during an ultramarathon run. METHODS Fifteen participants ran ≥104 km and had blood drawn: prior to start; 53; 104 km; and 24-h post run. Serum [Na(+)], CK, urea, creatinine and estimated glomerular filtration rate (eGFR) were measured from serial blood samples. Two-way repeated-measures ANOVA was used to examine differences regarding both race distance and natremia status. RESULTS Ten of 15 participants demonstrated EAH (serum [Na(+)] <135 mmol/L) at least once during serial testing. Participants were categorized post hoc into one of three natremia groups based on lowest recorded [Na(+)]: (1) <129 mmol/L (n = 3; moderate EAH); (2) between 129 and 134 mmol/L (n = 7; mild EAH); and (3) >134 mmol/L (n = 5; normonatremia). Participants with lowest [Na(+)] demonstrated highest CK values at subsequent checkpoints. Significant natremia group differences noted at the 53 km point (p = 0.0002) for [Na(+)] while significant natremia group effect noted for CK seen at the 24-h post-finish testing point (p = 0.02). Significant natremia group effects noted for renal biomarkers, with the moderate EAH group documenting the lowest eGFR (p = 0.005), and highest serum urea (p = 0.0006) and creatinine (p < 0.0001) levels. Hyponatremic runners had lower post-race urine [Na(+)] than normonatremic runners (26 ± 15 vs. 89 ± 79 mmol/L; p = 0.03). CONCLUSIONS Preliminary data support the possibility that transient hypovolemic EAH may precede and augment CK during an ultramarathon.
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Affiliation(s)
- Ross S Cairns
- Newcastle Sports Medicine, New Lambton, New South Wales, Australia
| | - Tamara Hew-Butler
- School of Health Science, 3157HHB, Oakland University, Rochester, MI, 48309-4482, USA.
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Hoffman MD, Stuempfle KJ, Valentino T. Sodium Intake During an Ultramarathon Does Not Prevent Muscle Cramping, Dehydration, Hyponatremia, or Nausea. SPORTS MEDICINE - OPEN 2015; 1:39. [PMID: 26709371 PMCID: PMC4688305 DOI: 10.1186/s40798-015-0040-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 12/16/2015] [Indexed: 11/18/2022]
Abstract
BACKGROUND Ultramarathon runners commonly believe that sodium replacement is important for prevention of muscle cramping, dehydration, hyponatremia, and nausea during prolonged continuous exercise. The purpose of this study was to measure total sodium intake to determine if these beliefs are supported. METHODS Participants of a 161-km ultramarathon (air temperature reaching 39 °C) provided full dietary information during the race, underwent body weight measurements before and after the race, completed a post-race questionnaire about muscle cramping and nausea or vomiting during the race, and had post-race plasma sodium concentration measured. RESULTS Among 20 finishers providing dietary data, mean (±SD) total sodium intake was 13,651 ± 8444 mg (range 2541-38,338 mg), and sodium in food and drink accounted for 66 % of the sodium when averaged across subjects (range 34-100 %). Sodium intake rates were similar when comparing the 10 % of subjects who were hyponatremic with those who were not hyponatremic, the 39 % with muscle cramping or near cramping with those without cramping, and the 57 % who reported having symptoms of nausea or vomiting with those without these symptoms. Weight change between race start and finish was significantly related to rate of sodium intake (r = 0.49, p = 0.030) and total sodium intake (r = 0.53, p = 0.016), but the maximum weight loss among those taking the least total sodium (<4400 mg total sodium during the race) was 4-5 % below the weight measured immediately pre-race. CONCLUSIONS Exercise-associated muscle cramping, dehydration, hyponatremia, and nausea or vomiting during exercise up to 30 h in hot environments are unrelated to total sodium intake, despite a common belief among ultramarathon runners that sodium is important for the prevention of these problems.
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Affiliation(s)
- Martin D. Hoffman
- Department of Physical Medicine & Rehabilitation, Department of Veterans Affairs, Sacramento VA Medical Center, Northern California Health Care System, 10535 Hospital Way, Sacramento, CA 95655-1200 USA
- Department of Physical Medicine & Rehabilitation, University of California Davis Medical Center, Sacramento, CA USA
| | | | - Taylor Valentino
- Department of Kinesiology, San Francisco State University, San Francisco, CA USA
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Mayer CU, Treff G, Fenske WK, Blouin K, Steinacker JM, Allolio B. High incidence of hyponatremia in rowers during a four-week training camp. Am J Med 2015; 128:1144-51. [PMID: 25912199 DOI: 10.1016/j.amjmed.2015.04.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 04/04/2015] [Accepted: 04/07/2015] [Indexed: 10/23/2022]
Abstract
PURPOSE To investigate the incidence of hyponatremia and its relationship to plasma copeptin, a surrogate marker for arginine vasopressin (AVP) during 28 days of high-volume rowing training. METHODS Thirty rowers from the German junior national team (21 male) were studied during a training camp. Serum sodium ([Na(+)]), osmolality, and copeptin were measured before the beginning of the camp (day 0), and at days 7, 13, 18, 24, and 28. Daily fluid intake, body weight, urine parameters, and training volume were recorded. RESULTS Seventy percent of the rowers developed hyponatremia at least once. At day 18, training volume and incidence of hyponatremia (43%) were highest. [Na(+)] decreased from 143 ± 9 mmol·L(-1) (day 0) to 135 ± 5 mmol·L(-1) (day 18, P < .01). Hyponatremia was correlated significantly with weight gain compared with the previous day (P < .01). Copeptin decreased from day 0 to 28 (male: 6.7 ± 2.8 to 3.6 ± 1.7 pmol·L(-1); P < .05; female: 4.8 ± 1.1 to 3.2 ± 1.5 pmol·L(-1); P < .05), being only partially suppressed. Relative fluid intake per body surface area increased from day 7 (male: 2.79 ± 0.78 L·m(-2); female: 2.20 ± 0.70 L·m(-2)) to day 28 (3.88 ± 0.69 L·m(2) and 2.65 ± 0.93 L·m(-2); P < .05). No athlete developed symptomatic hyponatremia. CONCLUSION Prolonged high-volume rowing training can lead to a high incidence of hyponatremia. Overdrinking and inadequate suppression of AVP contribute to its development.
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Affiliation(s)
- Constantin Ulrich Mayer
- Division of Sports and Rehabilitation Medicine, Department of Internal Medicine II, University of Ulm, Germany; Department of Orthopedics, Medical Faculty, University of Düsseldorf, Germany
| | - Gunnar Treff
- Division of Sports and Rehabilitation Medicine, Department of Internal Medicine II, University of Ulm, Germany
| | - Wiebke Kristin Fenske
- Department of Internal Medicine I, Endocrine Unit, University Hospital, University of Wuerzburg, Germany; IFB Adiposity Diseases, Leipzig University Medical Center, Germany
| | - Katja Blouin
- Department of Internal Medicine I, Endocrine Unit, University Hospital, University of Wuerzburg, Germany
| | - Jürgen Michael Steinacker
- Division of Sports and Rehabilitation Medicine, Department of Internal Medicine II, University of Ulm, Germany.
| | - Bruno Allolio
- Department of Internal Medicine I, Endocrine Unit, University Hospital, University of Wuerzburg, Germany; Comprehensive Heart Failure Center, University of Wuerzburg, Germany
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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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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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Lewis DP, Hoffman MD, Stuempfle KJ, Owen BE, Rogers IR, Verbalis JG, Hew-Butler TD. The need for salt: does a relationship exist between cystic fibrosis and exercise-associated hyponatremia? J Strength Cond Res 2014; 28:807-13. [PMID: 23897018 DOI: 10.1519/jsc.0b013e3182a35dbd] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Salt replacement is often recommended to prevent exercise-associated hyponatremia (EAH) despite a lack of evidence to support such practice. Exercise-associated hyponatremia is known to be a complex process resulting from the interplay of hydration, arginine vasopressin, and sodium balance. Although evidence suggests overhydration is the dominant pathophysiologic factor in most cases, the contributions of sweat sodium losses remain unclear. A theoretical genetic mechanism producing exuberant sweat sodium loss in athletes is the presence of cystic fibrosis (CF) gene. Individuals with CF develop hypovolemic hyponatremia by sodium loss via sweat through a defective chloride ion transport channel, the CF transmembrane conductance regulator (CFTR). Elevated sweat sodium concentrations in CF single heterozygotes suggest that athletes developing EAH may be CFTR carriers. We targeted the 2010 and 2011 Western States Endurance Run ultramarathon, an event where athletes with EAH regularly present in a hypovolemic state, for a cohort maximizing the potential to document such a relationship. A total of 798 runners started the 2010 (n = 423) and 2011 (n = 375) races. Of the 638 finishers, 373 were screened for EAH by blood draw, 60 (16%) were found to have EAH, and 31 (alpha = 0.05 for n = 9) reported their CF result from a saliva-based genetic testing kit. Neither the 31 EAH-positive athletes nor the 25 EAH-negative comparison cohort athletes tested positive for a CF mutation. This null relationship suggests that CFTR mutations are not associated with the development of EAH and that salt supplementation is unnecessary for such a reason.
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Affiliation(s)
- Douglas P Lewis
- 1Department of Family and Maternal/Child, Via Christi Family Medicine Residency, Via Christi Health System, Wichita, Kansas; 2Department of Physical Medicine and Rehabilitation, VA Northern California Health Care System and University of California Davis Medical Center, Sacramento, California; 3Department of Health Sciences, Gettysburg College, Gettysburg, Pennsylvania; 4Sir Charles Gairdner Hospital, Perth, Australia; 5Department of Emergency Medicine, St John of God Murdoch Hospital and University of Notre Dame, Murdoch, Western Australia; 6Division of Endocrinology and Metabolism, Georgetown University Medical Center, Washington, District of Columbia; and 7School of Health Science, Oakland University, Rochester, Michigan
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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: 14] [Impact Index Per Article: 1.4] [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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Owen BE, Rogers IR, Hoffman MD, Stuempfle KJ, Lewis D, Fogard K, Verbalis JG, Hew-Butler T. Efficacy of oral versus intravenous hypertonic saline in runners with hyponatremia. J Sci Med Sport 2014; 17:457-62. [DOI: 10.1016/j.jsams.2013.09.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Revised: 06/11/2013] [Accepted: 09/09/2013] [Indexed: 10/26/2022]
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Krabak BJ, Waite B, Lipman G. Evaluation and treatment of injury and illness in the ultramarathon athlete. Phys Med Rehabil Clin N Am 2014; 25:845-63. [PMID: 25442162 DOI: 10.1016/j.pmr.2014.06.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Participation in ultramarathon races and knowledge of these athletes continues to increase as the sport becomes more popular. Physicians and athletes need to better understand the impact of the unique aspects of ultramarathon races, such as race environment (temperature, humidity, and altitude), race distance, race stages, nutritional requirements and equipment, on athlete injuries and illness. Proper treatment of injuries and illnesses during an ultramarathon race is important for avoiding long-term medical issues. In this article, the evaluation and treatment of common musculoskeletal injuries and medical illnesses in ultramarathon runners are reviewed.
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Affiliation(s)
- Brian J Krabak
- Rehabilitation, Orthopedics, and Sports Medicine, University of Washington Sports Medicine, 3800 Montlake Boulevard Northeast, Box 354060, Seattle, WA 98195, USA; Seattle Children's Sports Medicine, 4800 Sand Point Way Northeast, Seattle, WA 98145, USA.
| | - Brandee Waite
- Physical Medicine and Rehabilitation, Sports Medicine, University of California Davis, 4860 Y Street, Suite 3850, Sacramento, CA 95817, USA
| | - Grant Lipman
- Division of Emergency Medicine, Department of Surgery, Stanford University School of Medicine, 300 Pasteur Dr Alway Bldg M121 MC 5119, Stanford, CA 94305, USA
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Ulsamer S, Rüst CA, Rosemann T, Lepers R, Knechtle B. Swimming performances in long distance open-water events with and without wetsuit. BMC Sports Sci Med Rehabil 2014; 6:20. [PMID: 24891942 PMCID: PMC4041346 DOI: 10.1186/2052-1847-6-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2013] [Accepted: 05/14/2014] [Indexed: 11/18/2022]
Abstract
Background Existing literature showed improved swimming performances for swimmers wearing wetsuits competing under standardized conditions in races held in pools on short to middle distances. Data about the influence of wetsuits on swimming performances in long and ultra-long open-water swimming races are missing. It is unknown whether the benefit of wearing wetsuits is comparable in men and women. The aim of this study was to investigate the influence of wearing a wetsuit on open-water swimming performances at the 26.4 km ‘Marathon Swim in Lake Zurich’ in Lake Zurich, Switzerland, and the 3.8 km Lake Ontario Swim Team-Race (LOST-Race) in Lake Ontario, Canada. Methods Race times of the fastest female and male swimmers competing with and without wetsuit were compared using multi-level regression analyses and analysis of variance. Results In the ‘Marathon Swim’ in Lake Zurich, wearing a wetsuit had no effect on race time regarding the gender where athletes wearing a wetsuit were not faster than athletes without wetsuit. However, the ten fastest men wearing a wetsuit (410.6 ± 26.7 min) were faster (32.7%, p < 0.01) than the ten fastest women without wetsuit (544.9 ± 81.3 min). In the ‘LOST-Race’, the top ten men wearing a wetsuit (51.7 ± 2.5 min) were faster (13.2%, p < 0.01) than the top ten women wearing a wetsuit (58.5 ± 3.2 min). Additionally, the top ten men without wetsuit (52.1 ± 2.4 min) were faster (19.6%, p < 0.01) than the top ten women without wetsuit (62.3 ± 2.5 min). The top ten women wearing a wetsuit (58.5 ± 3.2 min) were faster (6.5%, p < 0.01) than top ten women without a wetsuit (62.3 ± 25 min). Conclusions These results suggest that wearing a wetsuit had a positive influence on swimming speed for both women and men but the benefit of the use of wetsuits seemed to depend on additional factors (i.e. race distance). Women seemed to benefit more from wearing wetsuits than men in longer open-water ultra-distance swimming races.
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Affiliation(s)
- Sebastian Ulsamer
- 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
| | - Romuald Lepers
- INSERM U1093, Faculty of Sport Sciences, University of Burgundy, Dijon, France
| | - Beat Knechtle
- Facharzt FMH für Allgemeinmedizin, Vadianstrasse 26, Gesundheitszentrum St. Gallen, St. Gallen, Switzerland
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Medical Services at Ultra-Endurance Foot Races in Remote Environments: Medical Issues and Consensus Guidelines. Sports Med 2014; 44:1055-69. [DOI: 10.1007/s40279-014-0189-3] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Chlíbková D, Knechtle B, Rosemann T, Žákovská A, Tomášková I. The prevalence of exercise-associated hyponatremia in 24-hour ultra-mountain bikers, 24-hour ultra-runners and multi-stage ultra-mountain bikers in the Czech Republic. J Int Soc Sports Nutr 2014; 11:3. [PMID: 24512517 PMCID: PMC3929155 DOI: 10.1186/1550-2783-11-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Accepted: 02/05/2014] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND To assess the prevalence of exercise-associated hyponatremia (EAH) in two 24-hour mountain bike (MTB) (R1,R2), one 24-hour running (R3) and one multi-stage MTB (R4) races held in the Czech Republic in a cluster of four cross-sectional studies. METHODS In 27 ultra-mountain bikers (ultra-MTBers), 12 ultra-runners, and 14 multi-stage MTBers, fluid intake, changes (Δ) in body mass, hematocrit, plasma volume, plasma [Na+], plasma [K+], plasma osmolality, urine [Na+], urine [K+], urine specific gravity, urine osmolality, K+/Na+ ratio in urine, transtubular potassium gradient and glomerular filtration rate were measured and calculated. The use of non-steroidal anti-inflammatory drugs and symptoms of EAH were recorded using post-race questionnaires. RESULTS Of the 53 finishers, three (5.7%) developed post-race EAH, thereof one (3.7%) ultra-MTBer, one (8.3%) ultra-runner and one (7.1%) multi-stage MTBer. Plasma [Na+] decreased significantly (p < 0.001) only in R4. Urine osmolality (R1, R3, R4 p < 0.001; R2 p < 0.05) and glomerular filtration rate (p < 0.001) increased, and body mass decreased in all races (p < 0.05). Δ body mass was inversely related to the number of kilometers achieved (p < 0.001) in R2 where better ultra-MTBers tended to lose more weight. Δ body mass (p < 0.001) and %Δ body mass (p = 0.05) were positively related to lower post-race plasma [Na+] in R3 that was associated with increased loss in body mass. Fluid intake was positively related to race performance in R1 and R2 (R1: p = 0.04; R2: p = 0.01) where ultra-MTBers in R1 and R2 who drank more finished ahead of those who drank less. Post-race plasma [Na+] was negatively associated with race performance in ultra-MTBers in R2 (p < 0.05), similarly ultra-runners in R3 (p < 0.05) where finishers with more kilometres had lower post-race plasma [Na+]. CONCLUSIONS The prevalence of EAH in the Czech Republic was no higher compared to existing reports on ultra-endurance athletes in other countries. Lower plasma [Na+] and development of EAH may be attributed to overdrinking, a pituitary secretion of vasopressin, an impaired mobilization of osmotically inactive sodium stores, and/or an inappropriate inactivation of osmotically active sodium.
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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
- Facharzt FMH für Allgemeinmedizin, Gesundheitszentrum St. Gallen, Vadianstrasse 26, 9001 St. Gallen, 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
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Black KE, Skidmore P, Brown RC. Fluid balance of cyclists during a 387-km race. Eur J Sport Sci 2014; 14 Suppl 1:S421-8. [PMID: 24444237 DOI: 10.1080/17461391.2012.711860] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Current hydration guidelines are designed to address the fine balance between minimising dehydration while reducing the risk of hyponatremia. During prolonged cycling events small discrepancies between drinking behaviour and fluid requirements may be detrimental to health and performance. The present study aimed to investigate the hydration practices of competitors in a 387 km cycle race in order to evaluate the effect on fluid balance and monitor the prevalence of dysnatremia. Eighteen participants provided blood and urine samples pre- and post-race to measure sodium and fluid balance. Sweat samples were collected via patches for analysis of sodium concentration. Body weight was measured at the start and end of the race. On average participants consumed 0.58 L h(-1) of fluid. Upon completion of the race 7 of the 18 (39%) cyclists had blood sodium concentrations of 135 mmol L(-1) or lower with one cyclist recording a value of 132 mmol L(-1). Only two cyclists appeared to be moderately dehydrated. A post-race questionnaire indicated cyclists were most concerned with preventing dehydration. It appears that cyclists taking part in prolonged endurance events are at more risk of hyponatremia than dehydration and do not readily change their drinking behaviour to match their sweat losses.
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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. Wilderness Environ Med 2013; 24:228-40. [DOI: 10.1016/j.wem.2013.01.011] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Revised: 01/09/2013] [Accepted: 01/25/2013] [Indexed: 11/24/2022]
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Hoffman MD, Fogard K, Winger J, Hew-Butler T, Stuempfle KJ. Characteristics of 161-km Ultramarathon Finishers Developing Exercise-Associated Hyponatremia. Res Sports Med 2013; 21:164-75. [DOI: 10.1080/15438627.2012.757230] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Martin D. Hoffman
- a Department of Physical Medicine & Rehabilitation, Department of Veterans Affairs , Northern California Health Care System , Sacramento , California , USA
- b Department of Physical Medicine & Rehabilitation , University of California Davis Medical Center, Sacramento , Sacramento , California , USA
| | - Kevin Fogard
- a Department of Physical Medicine & Rehabilitation, Department of Veterans Affairs , Northern California Health Care System , Sacramento , California , USA
| | - James Winger
- c Department of Family Medicine , Loyola Stritch School of Medicine , Maywood , Illinois , USA
| | - Tamara Hew-Butler
- d Exercise Science Program , Oakland University , Rochester , Michigan , USA
| | - Kristin J. Stuempfle
- e Health Sciences Department , Gettysburg College , Gettysburg , Pennsylvania , USA
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The effect of physiology and hydration beliefs on race behavior and postrace sodium in 161-km ultramarathon finishers. Int J Sports Physiol Perform 2013; 8:536-41. [PMID: 23412802 DOI: 10.1123/ijspp.8.5.536] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
PURPOSE To determine if beliefs about physiology and rehydration affect ultramarathon runners' hydration behaviors or if these beliefs increase the risk for exercise-associated hyponatremia (EAH). METHODS Participants of the 2011 161-km Western States Endurance Run completed a prerace questionnaire, prerace and postrace body-mass measurements, and postrace assessment of serum sodium ([Na⁺]). RESULTS Of 310 finishers, 309 (99.7%) completed the prerace questionnaire and 207 (67%) underwent postrace blood studies. Twelve (5.8%) finishers had asymptomatic EAH ([Na⁺] range 131-134 mmol/L). The most common hydration plan (43.1%) was drinking according to schedule, and these runners did so to replace fluid lost when sweating (100%) and to avoid dehydration (81.2%). Prerace drinking plan was not associated with postrace [Na⁺] or the development of postrace hyponatremia. There also were no group differences between those with and those without EAH for any other variables including planned energy intake or knowledge of fluid balance. Runners not planning to drink to thirst trended toward more influence from advertisements (P = .056) and were significantly more influenced by scientific organizations (P = .043) than runners with other drinking plans. Finally, runners who believe that EAH is caused by excessive drinking adopted a lower-volume drinking plan (P = .005), while runners who believe that EAH is caused by sodium loss via sweating reported more common use of sodium supplementation during the race (P = .017). CONCLUSIONS Beliefs regarding the causes of EAH alter race behaviors including drinking plan and sodium supplementation but do not appear to affect the likelihood of developing EAH during a 161-km ultramarathon.
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Water and sodium intake habits and status of ultra-endurance runners during a multi-stage ultra-marathon conducted in a hot ambient environment: an observational field based study. Nutr J 2013; 12:13. [PMID: 23320854 PMCID: PMC3554439 DOI: 10.1186/1475-2891-12-13] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2012] [Accepted: 01/11/2013] [Indexed: 12/14/2022] Open
Abstract
Background Anecdotal evidence suggests ultra-runners may not be consuming sufficient water through foods and fluids to maintenance euhydration, and present sub-optimal sodium intakes, throughout multi-stage ultra-marathon (MSUM) competitions in the heat. Subsequently, the aims were primarily to assess water and sodium intake habits of recreational ultra-runners during a five stage 225 km semi self-sufficient MSUM conducted in a hot ambient environment (Tmax range: 32°C to 40°C); simultaneously to monitor serum sodium concentration, and hydration status using multiple hydration assessment techniques. Methods Total daily, pre-stage, during running, and post-stage water and sodium ingestion of ultra-endurance runners (UER, n = 74) and control (CON, n = 12) through foods and fluids were recorded on Stages 1 to 4 by trained dietetic researchers using dietary recall interview technique, and analysed through dietary analysis software. Body mass (BM), hydration status, and serum sodium concentration were determined pre- and post-Stages 1 to 5. Results Water (overall mean (SD): total daily 7.7 (1.5) L/day, during running 732 (183) ml/h) and sodium (total daily 3.9 (1.3) g/day, during running 270 (151) mg/L) ingestion did not differ between stages in UER (p < 0.001 vs. CON). Exercise-induced BM loss was 2.4 (1.2)% (p < 0.001). Pre- to post-stage BM gains were observed in 26% of UER along competition. Pre- and post-stage plasma osmolality remained within normal clinical reference range (280 to 303 mOsmol/kg) in the majority of UER (p > 0.05 vs. CON pre-stage). Asymptomatic hyponatraemia (<135 mmol/L) was evident pre- and post-stage in n = 8 UER, corresponding to 42% of sampled participants. Pre- and post-stage urine colour, urine osmolality and urine/plasma osmolality ratio increased (p < 0.001) as competition progressed in UER, with no change in CON. Plasma volume and extra-cellular water increased (p < 0.001) 22.8% and 9.2%, respectively, from pre-Stage 1 to 5 in UER, with no change in CON. Conclusion Water intake habits of ultra-runners during MSUM conducted in hot ambient conditions appear to be sufficient to maintain baseline euhydration levels. However, fluid over-consumption behaviours were evident along competition, irrespective of running speed and gender. Normonatraemia was observed in the majority of ultra-runners throughout MSUM, despite sodium ingestion under benchmark recommendations.
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Hoffman MD, Stuempfle KJ, Fogard K, Hew-Butler T, Winger J, Weiss RH. Urine dipstick analysis for identification of runners susceptible to acute kidney injury following an ultramarathon. J Sports Sci 2012; 31:20-31. [PMID: 23035796 DOI: 10.1080/02640414.2012.720705] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
This study examined whether urine dipstick testing might be useful to predict the development of acute kidney injury after an ultramarathon. Participants in the 2011 161-km Western States Endurance Run underwent post-race blood and urine dipstick analyses. Of the 310 race finishers, post-race urine dipstick testing was completed on 152 (49%) and post-race blood also was obtained from 150 of those runners. Based on "injury" and "risk" criteria for acute kidney injury of blood creatinine 2.0 and 1.5 times estimated baseline, respectively, 4% met the criteria for injury and an additional 29-30% met the criteria for risk of injury. Those meeting the injury criteria had higher creatine kinase concentrations (P < 0.001) than those not meeting the criteria. Urine dipstick tests that read positive for at least 1+ protein, 3+ blood, and specific gravity ≥ 1.025 predicted those meeting the injury criteria with sensitivity of 1.00 (95% confidence interval [CI] 0.54-1.00), specificity of 0.76 (95% CI 0.69-0.83), positive predictive value of 0.15 (95% CI 0.06-0.30), negative predictive value of 1.00 (95% CI 0.97-1.00), and likelihood ratio for a positive test of 4.2. We conclude that urine dipstick testing was successfully able to identify those individuals meeting injury criteria for acute kidney injury with excellent sensitivity and specificity.
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Affiliation(s)
- Martin D Hoffman
- Department of Physical Medicine & Rehabilitation-117, Sacramento VA Medical Center, 10535 Hospital Way, Sacramento, CA 95655-1200, USA.
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Brown S, Chiampas G, Jaworski C, Passe D. Lack of awareness of fluid needs among participants at a midwest marathon. Sports Health 2012; 3:451-4. [PMID: 23016042 PMCID: PMC3445216 DOI: 10.1177/1941738111415043] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Marathon running has become popular, particularly among inexperienced runners. HYPOTHESIS Many marathoners are inexperienced and lack concern for potential complications of marathon running. STUDY DESIGN Cross-sectional survey. METHODS In sum, 419 runners completed a survey on a variety of topics regarding training for a marathon and hydration strategies. RESULTS Overall, 211 females (38.3 ± 9.1 years old) and 208 males (41.6 ± 11.0 years old) participated. They trained for 6.8 ± 4.3 months and had run for 9.8 ± 9.1 years; 33.5% had no marathon experience and 16.9% had run 1 marathon. Of the injuries reported, 77.6% and 72.9% were minor musculoskeletal injuries during the current and previous running seasons, respectively. Of the 278 runners who had run a marathon, 54 (19.0%) had been treated in the medical tent, 31.5% of whom for dehydration. Furthermore, 54.9% and 64.3% of the survey participants were "not at all" concerned with musculoskeletal injury and hyponatremia, respectively. Also, 88.7% did not know their sweat rate; 67.8% did not weigh themselves; and 81.3% had no other method of hydration assessment. No significant correlations were found between concern for hyponatremia and age, sex, or experience. CONCLUSIONS Most participants were inexperienced, lacked concern for injury or hyponatremia, and were not using methods of hydration assessment.
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Affiliation(s)
- Sara Brown
- Loyola University Medical Center, Chicago, Illinois
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Stuempfle KJ, Hoffman MD, Weschler LB, Rogers IR, Hew-Butler T. Race diet of finishers and non-finishers in a 100 mile (161 km) mountain footrace. J Am Coll Nutr 2012; 30:529-35. [PMID: 22331688 DOI: 10.1080/07315724.2011.10719999] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
OBJECTIVE To determine if food and fluid intake is related to completion of a 161-km ultramarathon. METHODS Sixteen consenting runners in the Western States Endurance Run participated in the study. Race diets were analyzed using Nutritionist Pro software. Both total intake and intake by race segment (3 total) were evaluated. RESULTS Six of 16 subjects completed the race (finishers) in 27.0 ± 2.3 hours (mean ± SD). Non-finishers completed 96.5 ± 20.5 km in 17.0 ± 3.9 h. Overall consumption rates of kilocalories, carbohydrate, fat, and sodium were significantly greater (P < 0.05) in finishers (4.6 ± 1.7 kcal/kg/h, 0.98 ± 0.43 g carbohydrate/kg/h, 0.06 ± 0.03 g fat/kg/h, 10.2 ± 6.0 mg sodium/kg/h) versus non-finishers (2.5 ± 1.3 kcal/kg/h, 0.56 ± 0.32 g carbohydrate/kg/h, 0.02 ± 0.02 g fat/kg/h, 5.2 ± 3.0 mg sodium/kg/h). Kilocalorie, fat, fluid, and sodium consumption rates during segment 1 (first 48 km) were significantly greater in finishers than in non-finishers. CONCLUSIONS Completion of this 161-km race was related to greater fuel, fluid, and sodium consumption rates. However, intake ranges for the finishers were large, so factors other than race diet may have contributed to the successful completion of the race.
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Affiliation(s)
- Kristin J Stuempfle
- Health Sciences Department, Gettysburg College, Gettysburg, Pennsylvania 17325, USA.
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Cejka C, Knechtle B, Knechtle P, Rüst CA, Rosemann T. An increased fluid intake leads to feet swelling in 100-km ultra-marathoners - an observational field study. J Int Soc Sports Nutr 2012; 9:11. [PMID: 22472466 PMCID: PMC3366912 DOI: 10.1186/1550-2783-9-11] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Accepted: 04/03/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND An association between fluid intake and changes in volumes of the upper and lower limb has been described in 100-km ultra-marathoners. The purpose of the present study was (i) to investigate the association between fluid intake and a potential development of peripheral oedemas leading to an increase of the feet volume in 100-km ultra-marathoners and (ii) to evaluate a possible association between the changes in plasma sodium concentration ([Na+]) and changes in feet volume. METHODS In seventy-six 100-km ultra-marathoners, body mass, plasma [Na+], haematocrit and urine specific gravity were determined pre- and post-race. Fluid intake and the changes of volume of the feet were measured where the changes of volume of the feet were estimated using plethysmography. RESULTS Body mass decreased by 1.8 kg (2.4%) (p < 0.0001); plasma [Na+] increased by 1.2% (p < 0.0001). Haematocrit decreased (p = 0.0005). The volume of the feet remained unchanged (p > 0.05). Plasma volume and urine specific gravity increased (p < 0.0001). Fluid intake was positively related to the change in the volume of the feet (r = 0.54, p < 0.0001) and negatively to post-race plasma [Na+] (r = -0.28, p = 0.0142). Running speed was negatively related to both fluid intake (r = -0.33, p = 0.0036) and the change in feet volume (r = -0.23, p = 0.0236). The change in the volume of the feet was negatively related to the change in plasma [Na+] (r = -0.26, p = 0.0227). The change in body mass was negatively related to both post-race plasma [Na+] (r = -0.28, p = 0.0129) and running speed (r = -0.34, p = 0.0028). CONCLUSIONS An increase in feet volume after a 100-km ultra-marathon was due to an increased fluid intake.
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Affiliation(s)
- Caroline Cejka
- Institute of General Practice and for Health Services Research, University of Zurich, Zurich, Switzerland.
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Abstract
PURPOSE To determine the incidence of exercise-associated hyponatremia (EAH), the associated biochemical measurements and risk factors for EAH, and whether there is an association between postrace blood sodium concentration ([Na+]) and changes in body mass among participants in the 2009 Western States Endurance Run, a 161-km mountain trail run. METHODS Change in body mass, postrace [Na+], and blood creatine phosphokinase (CPK) concentration, and selected runner characteristics were evaluated among consenting competitors. RESULTS Of the 47 study participants, 14 (30%) had EAH as defined by a postrace [Na+] <135 mmol/L. Postrace [Na+] and percent change in body mass were directly related (r = .30, P = .044), and 50% of those with EAH had body mass losses of 3-6%. EAH was unrelated to age, sex, finish time, or use of nonsteroidal anti-inflammatory drugs during the run, but those with EAH had completed a smaller (P = .03) number of 161-km ultramarathons. The relationship of CPK levels to postrace [Na+] did not reach statistical significance (r = -.25, P = .097). CONCLUSIONS EAH was common (30%) among finishers of this 161-km ultramarathon and it was not unusual for those with EAH to be dehydrated. As such, changes in body mass should not be relied upon in the assessment for EAH during 161-km ultramarathons.
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Abstract
PURPOSE Fluid overload is considered a main risk factor for exercise-associated hyponatremia (EAH). The aim of this study was to investigate the incidence of EAH in ultra-runners at the 100 km ultra-run in Biel, Switzerland. METHODS Pre- and postrace, body mass, urinary specific gravity, hemoglobin, hematocrit, plasma [Na+], and plasma volume were determined. RESULTS Of the 145 finishers, seven runners (4.8%) developed asymptomatic EAH. While running, the athletes consumed a total of (median and interquartile ranges) 6.9 (5.1-8.8) L over the 100 km distance, equal to 0.58 (0.41-0.79) L/h. Fluid intake correlated negatively and significantly with race time (r = -.50, P < .0001). Body mass decreased, plasma [Na+] remained unchanged, hematocrit and hemoglobin decreased, and urinary specific gravity increased. Plasma volume increased by 4.6 (-2.3 to 12.8) %. Change in body mass correlated with both postrace plasma [Na+] and Δ plasma [Na+]. Postrace plasma [Na+] correlated to Δ plasma [Na+]. Fluid intake was associated neither with postrace plasma [Na+] nor with Δ plasma [Na+]. Fluid intake was related to Δ body mass (r = .21, P = .012), but not to postrace body mass. Fluid intake showed no correlation to Δ plasma volume. Change in plasma volume was associated with postrace [Na+]. CONCLUSIONS Incidences of EAH in 100 km ultra-marathoners were lower compared with reports on marathoners. Body mass decreased, plasma volume increased, and plasma [Na+] was maintained. Since fluid intake was related neither to Δ plasma volume nor to Δ plasma [Na+], we assume that factors other than fluid intake maintained body fluid homeostasis.
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