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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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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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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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Whatmough S, Mears S, Kipps C. Serum sodium changes in marathon participants who use NSAIDs. BMJ Open Sport Exerc Med 2018; 4:e000364. [PMID: 30588325 PMCID: PMC6280910 DOI: 10.1136/bmjsem-2018-000364] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/12/2018] [Indexed: 11/04/2022] Open
Abstract
Introduction The primary mechanism through which the development of exercise-associated hyponatraemia (EAH) occurs is excessive fluid intake. However, many internal and external factors have a role in the maintenance of total body water and non-steroidal anti-inflammatory medications (NSAIDs) have been implicated as a risk factor for the development of EAH. This study aimed to compare serum sodium concentrations ([Na]) in participants taking an NSAID before or during a marathon (NSAID group) and those not taking an NSAID (control group). Methods Participants in a large city marathon were recruited during race registration to participate in this study. Blood samples and body mass measurements took place on the morning of the marathon and immediately post marathon. Blood was analysed for [Na]. Data collected via questionnaires included athlete demographics, NSAID use and estimated fluid intake. Results We obtained a full data set for 28 participants. Of these 28 participants, 16 took an NSAID on the day of the marathon. The average serum [Na] decreased by 2.1 mmol/L in the NSAID group, while it increased by 2.3 mmol/L in the control group NSAID group (p=0.0039). Estimated fluid intake was inversely correlated with both post-marathon serum [Na] and ∆ serum [Na] (r=-0.532, p=0.004 and r=-0.405 p=0.032, respectively). Conclusion Serum [Na] levels in participants who used an NSAID decreased over the course of the marathon while it increased in those who did not use an NSAID. Excessive fluid intake during a marathon was associated with a lower post-marathon serum [Na].
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Affiliation(s)
- Steven Whatmough
- Institute of Sport, Exercise and Health, University College London, London, UK
| | | | - Courtney Kipps
- Institute of Sport, Exercise and Health, University College London, London, UK
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Getzin AR, Milner C, Harkins M. Fueling the Triathlete: Evidence-Based Practical Advice for Athletes of All Levels. Curr Sports Med Rep 2018; 16:240-246. [PMID: 28696986 DOI: 10.1249/jsr.0000000000000386] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Triathletes need to effectively fuel during training and racing to maximize their potential for success. While most research on fueling has focused on elite male triathletes, triathlon participation encompasses a broader demographic of racers ranging from those with aspirations of winning to those whose goals are completion. Carbohydrate is the primary macronutrient for fueling endurance activities. Athletes can usually tolerate 60 to 90 mg·h in the form of multiple different carbohydrate sources. Athletes should drink as thirst dictates and consider sodium replacement of sweat loss especially in individuals with a history of exercise-associated muscle cramps. Caffeine is a known ergogenic aid that could be dosed at 3 mg·kg to maximize benefits of mental alertness while limiting potential side effects. Athletes need to balance fueling with development of exercise-induced gastrointestinal syndrome. As demographics of race participants change, understanding the special fueling needs of obese triathletes can encourage participation while minimizing bad outcomes.
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Affiliation(s)
- Andrew R Getzin
- 1Cayuga Medical Center, Ithaca, NY; 2Cayuga Center for Healthy Living, Cayuga Medical Center, Ithaca, NY; and 3Cayuga Center for Metabolic and Bariatric Surgery, Cayuga Medical Center, Ithaca, NY
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Martínez-Navarro I, Chiva-Bartoll O, Hernando B, Collado E, Porcar V, Hernando C. Hydration Status, Executive Function, and Response to Orthostatism After a 118-km Mountain Race: Are They Interrelated? J Strength Cond Res 2018; 32:441-449. [DOI: 10.1519/jsc.0000000000001614] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Hew-Butler T, Loi V, Pani A, Rosner MH. Exercise-Associated Hyponatremia: 2017 Update. Front Med (Lausanne) 2017; 4:21. [PMID: 28316971 PMCID: PMC5334560 DOI: 10.3389/fmed.2017.00021] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2016] [Accepted: 02/16/2017] [Indexed: 12/21/2022] Open
Abstract
Exercise-associated hyponatremia (EAH) was initially described in the 1980s in endurance athletes, and work done since then has conclusively identified that overdrinking beyond thirst and non-osmotic arginine vasopressin release are the most common etiologic factors. In recent years, EAH has been described in a broader variety of athletic events and also has been linked to the development of rhabdomyolysis. The potential role of volume and sodium depletion in a subset of athletes has also been described. This review focuses on the most recent literature in the field of EAH and summarizes key new findings in the epidemiology, pathophysiology, treatment, and prevention of this condition.
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Affiliation(s)
| | - Valentina Loi
- SC Nephrology and Dialysis, Brotzu Hospital , Cagliari , Italy
| | - Antonello Pani
- SC Nephrology and Dialysis, Brotzu Hospital , Cagliari , Italy
| | - Mitchell H Rosner
- Department of Medicine, University of Virginia Health System , Charlottesville, VA , USA
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Chlíbková D, Rosemann T, Knechtle B, Sengeis M, Posh L, Tomášková I. Pre-race characteristics and race performance in hyponatremic and normonatremic finishers of Czech ultra-races. ACTA GYMNICA 2016. [DOI: 10.5507/ag.2016.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Lopez RM, Casa DJ, Jensen KA, Stearns RL, DeMartini JK, Pagnotta KD, Roti MW, Armstrong LE, Maresh CM. Comparison of Two Fluid Replacement Protocols During a 20-km Trail Running Race in the Heat. J Strength Cond Res 2016; 30:2609-16. [PMID: 26840437 DOI: 10.1519/jsc.0000000000001359] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Lopez, RM, Casa, DJ, Jensen, K, Stearns, RL, DeMartini, JK, Pagnotta, KD, Roti, MW, Armstrong, LE, and Maresh, CM. Comparison of two fluid replacement protocols during a 20-km trail running race in the heat. J Strength Cond Res 30(9): 2609-2616, 2016-Proper hydration is imperative for athletes striving for peak performance and safety, however, the effectiveness of various fluid replacement strategies in the field setting is unknown. The purpose of this study was to investigate how two hydration protocols affect physiological responses and performance during a 20-km trail running race. A randomized, counter-balanced, crossover design was used in a field setting (mean ± SD: WBGT 28.3 ± 1.9° C). Well-trained male (n = 8) and female (n = 5) runners (39 ± 14 years; 175 ± 9 cm; 67.5 ± 11.1 kg; 13.4 ± 4.6% BF) completed two 20-km trail races (5 × 4-km loop) with different water hydration protocols: (a) ad libitum (AL) consumption and (b) individualized rehydration (IR). Data were analyzed using repeated measures ANOVA. Paired t-tests compared pre-race-post-race measures. Main outcome variables were race time, heart rate (HR), gastrointestinal temperature (TGI), fluid consumed, percent body mass loss (BML), and urine osmolality (Uosm). Race times between groups were similar. There was a significant condition × time interaction (p = 0.048) for HR, but TGI was similar between conditions. Subjects replaced 30 ± 14% of their water losses in AL and 64 ± 16% of their losses in IR (p < 0.001). Ad libitum trial experienced greater BML (-2.6 ± 0.5%) compared with IR (-1.3 ± 0.5%; p < 0.001). Pre-race to post-race Uosm differences existed between AL (-273 ± 146 mOsm) and IR (-145 ± 215 mOsm, p = 0.032). In IR, runners drank twice as much fluid than AL during the 20-km race, leading to > 2% BML in AL. Ad libitum drinking resulted in 1.3% greater BML over the 20-km race, which resulted in no thermoregulatory or performance differences from IR.
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Affiliation(s)
- Rebecca M Lopez
- 1Morsani College of Medicine, University of South Florida, Tampa, Florida; 2Department of Kinesiology, Korey Stringer Institute, University of Connecticut, Storrs, Connecticut; 3College of Health Professions, Sacred Heart University, Fairfield, CT; 4Department of Kinesiology, Temple University, Philadelphia, Pennsylvania; 5Department of Movement Science, Sport & Leisure Studies, Westfield State University, Westfield, Massachusetts; and 6Department of Human Sciences, Ohio State University, Columbus, Ohio
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Knechtle B, Knechtle R, Stiefel M, Zingg MA, Rosemann T, Rüst CA. Variables that influence Ironman triathlon performance - what changed in the last 35 years? Open Access J Sports Med 2015; 6:277-90. [PMID: 26346992 PMCID: PMC4556299 DOI: 10.2147/oajsm.s85310] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
OBJECTIVE This narrative review summarizes findings for Ironman triathlon performance and intends to determine potential predictor variables for Ironman race performance in female and male triathletes. METHODS A literature search was performed in PubMed using the terms "Ironman", "triathlon", and "performance". All resulting articles were searched for related citations. RESULTS Age, previous experience, sex, training, origin, anthropometric and physiological characteristics, pacing, and performance in split disciplines were predictive. Differences exist between the sexes for anthropometric characteristics. The most important predictive variables for a fast Ironman race time were age of 30-35 years (women and men), a fast personal best time in Olympic distance triathlon (women and men), a fast personal best time in marathon (women and men), high volume and high speed in training where high volume was more important than high speed (women and men), low body fat, low skin-fold thicknesses and low circumference of upper arm (only men), and origin from the United States of America (women and men). CONCLUSION These findings may help athletes and coaches to plan an Ironman triathlon career. Age and previous experience are important to find the right point in the life of a triathlete to switch from the shorter triathlon distances to the Ironman distance. Future studies need to correlate physiological characteristics such as maximum oxygen uptake with Ironman race time to investigate their potential predictive value and to investigate socio-economic aspects in Ironman triathlon.
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Affiliation(s)
- Beat Knechtle
- Gesundheitszentrum St Gallen, St Gallen, Switzerland ; Institute of Primary Care, University of Zurich, Zurich, Switzerland
| | - Raphael Knechtle
- Institute of Primary Care, University of Zurich, Zurich, Switzerland
| | - Michael Stiefel
- Institute of Primary Care, University of Zurich, Zurich, Switzerland
| | | | - Thomas Rosemann
- Institute of Primary Care, University of Zurich, Zurich, Switzerland
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Lemos R, Rosa Neto F, Mara LSD, Lineburger AA, Carvalho TD, Ramos R. Peso corporal e estado hídrico de triatletas no Ironman Brasil: Um fator de correção. REV BRAS MED ESPORTE 2015. [DOI: 10.1590/1517-869220152104137358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
INTRODUÇÃO: O triatlo Ironman é uma prova de longa duração em que comumente se observam alterações hidroeletrolíticas. A desidratação e hiponatremia são prevalentes e o diagnóstico diferencial entre elas deve levar em conta a variação de peso corporal do atleta. Contudo, deve-se considerar também que as variações são um somatório de fontes hídricas e não hídricas, sendo necessário aplicar um fator de correção para avaliação do real estado hídrico do atleta. Objetivo: Avaliar o estado hídrico do atleta baseado nas variações de peso corporal sem e com aplicação de fator de correção.MÉTODO: Vinte e seis atletas foram pesados em três momentos distintos (dois dias antes da prova, imediatamente antes e após a realização). O estado hídrico foi classificado com base no cálculo da variação percentual de peso corporal isolado e com aplicação do fator de correção de 1 kg proporcional ao atleta de 70 kg. Além disso, foram registrados os principais sinais clínicos e sintomas referidos.RESULTADOS: Nas 48 horas que antecederam a largada houve um ganho médio de peso de 1,2 kg. Após a prova, vinte e três (88,4%) atletas foram classificados como desidratados inicialmente, porém após a aplicação do fator de correção à variação do peso, esse número caiu para 12 (46,1%). Dos classificados como desidratação severa houve redução de 7 (26,2%) para nenhum atleta. Dez atletas (3,8%) apresentaram sinais e sintomas de desidratação.CONCLUSÃO: A classificação do estado de hidratação baseado nas perdas hídricas durante a prova foi significativamente modificado pela aplicação do fator de correção, sendo sua utilização justificada pelas evidências de que o ganho de peso nas 48 horas anteriores à prova está possivelmente relacionado ao acúmulo muscular de glicogênio e água (fontes não hídricas intravasculares).
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Affiliation(s)
| | | | | | | | | | - Renata Ramos
- Universidade do Estado de Santa Catarina, Brazil
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12
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Abstract
OBJECTIVE To determine body weight and serum [Na] changes in runners completing an 85-km mountain run, particularly with reference to their "in-race" hydration protocols. DESIGN Prospective observational cohort study. SETTING Cradle Mountain Run, Tasmania, Australia, February 2011. PARTICIPANTS Forty-four runners (86% of starters) prospectively enrolled, with 41 runners (80% of starters) eligible for inclusion in final data set. MAIN OUTCOME MEASURES Body weight change, serum sodium concentration change, and hydration plan (according to thirst vs preplanned fluid consumption). RESULTS There was 1 case of exercise-associated hyponatremia (EAH) [postrace [Na], 132 mmol/L]. This runner was asymptomatic. There was a strongly significant correlation between the change in serum [Na] and body weight change during the race. There was a significant inverse correlation between serum [Na] and volume of fluid consumed. Change of serum [Na] was not correlated with the proportion of water versus electrolyte drink consumed. Runners drinking to thirst consumed significantly lower average fluid volumes and had higher postrace serum [Na] than those complying with a preplanned hydration protocol (142 mmol/L vs 139 mmol/L). More experienced runners tended to drink to thirst. CONCLUSIONS There was a 2% incidence of EAH in this study. Serum [Na] change during an 85-km mountain run was inversely correlated with the volume of fluid consumed. The results provide further evidence that EAH is a dilutional hyponatremia caused by excessive consumption of hypotonic fluids. Drinking to thirst represents a safe hydration strategy for runners in a wilderness environment. CLINICAL RELEVANCE Drinking to thirst during endurance running events should be promoted as a safe hydration practice.
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Hew-Butler T, Rosner MH, Fowkes-Godek S, Dugas JP, Hoffman MD, Lewis DP, Maughan RJ, Miller KC, Montain SJ, Rehrer NJ, Roberts WO, Rogers IR, Siegel AJ, Stuempfle KJ, Winger JM, Verbalis JG. Statement of the Third International Exercise-Associated Hyponatremia Consensus Development Conference, Carlsbad, California, 2015. Clin J Sport Med 2015; 25:303-20. [PMID: 26102445 DOI: 10.1097/jsm.0000000000000221] [Citation(s) in RCA: 121] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Tamara Hew-Butler
- *Exercise Science Program, Oakland University, Rochester, Michigan; †Division of Nephrology, University of Virginia Health System, Charlottesville, Virginia; ‡Department of Sports Medicine, West Chester University, West Chester, Pennsylvania; §The Vitality Group, Chicago, Illinois; ¶Department of Physical Medicine and Rehabilitation, VA Northern California Health Care System and University of California Davis, Sacramento, California; ‖Family Medicine Residency Program, Via Christi Hospitals Wichita, Inc, Wichita, Kansas; **Department of Sport and Exercise Nutrition, Loughborough University, Leicestershire, United Kingdom; ††Athletic Training Program, Central Michigan University, Mount Pleasant, Michigan; ‡‡Military Nutrition Division, United States Army Research Institute of Environmental Medicine, Natick, Massachusetts; §§School of Physical Education, Sport and Exercise Science, University of Otago, Dunedin, New Zealand; ¶¶Department of Family Medicine and Community Health, University of Minnesota, Minneapolis, Minnesota; ‖‖Department of Emergency Medicine, St John of God Murdoch Hospital and University of Notre Dame, Perth, Western Australia; ***Department of Internal Medicine, Harvard Medical School, Boston, Massachusetts; †††Health Sciences Department, Gettysburg College, Gettysburg, Pennsylvania; ‡‡‡Department of Family Medicine, Loyola University Chicago Stritch School of Medicine, Chicago, Illinois; and §§§Department of Endocrinology and Metabolism, Georgetown University Medical Center, Washington, District of Columbia
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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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Knechtle B, Zingg MA, Rosemann T, Stiefel M, Rüst CA. What predicts performance in ultra-triathlon races? - a comparison between Ironman distance triathlon and ultra-triathlon. Open Access J Sports Med 2015; 6:149-59. [PMID: 26056498 PMCID: PMC4445872 DOI: 10.2147/oajsm.s79273] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Objective This narrative review summarizes recent intentions to find potential predictor variables for ultra-triathlon race performance (ie, triathlon races longer than the Ironman distance covering 3.8 km swimming, 180 km cycling, and 42.195 km running). Results from studies on ultra-triathletes were compared to results on studies on Ironman triathletes. Methods A literature search was performed in PubMed using the terms “ultra”, “triathlon”, and “performance” for the aspects of “ultra-triathlon”, and “Ironman”, “triathlon”, and “performance” for the aspects of “Ironman triathlon”. All resulting papers were searched for related citations. Results for ultra-triathlons were compared to results for Ironman-distance triathlons to find potential differences. Results Athletes competing in Ironman and ultra-triathlon differed in anthropometric and training characteristics, where both Ironmen and ultra-triathletes profited from low body fat, but ultra-triathletes relied more on training volume, whereas speed during training was related to Ironman race time. The most important predictive variables for a fast race time in an ultra-triathlon from Double Iron (ie, 7.6 km swimming, 360 km cycling, and 84.4 km running) and longer were male sex, low body fat, age of 35–40 years, extensive previous experience, a fast time in cycling and running but not in swimming, and origins in Central Europe. Conclusion Any athlete intending to compete in an ultra-triathlon should be aware that low body fat and high training volumes are highly predictive for overall race time. Little is known about the physiological characteristics of these athletes and about female ultra-triathletes. Future studies need to investigate anthropometric and training characteristics of female ultra-triathletes and what motivates women to compete in these races. Future studies need to correlate physiological characteristics such as maximum oxygen uptake (VO2max) with ultra-triathlon race performance in order to investigate whether these characteristics are also predictive for ultra-triathlon race performance.
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Affiliation(s)
- Beat Knechtle
- Institute of Primary Care, University of Zurich, Zurich, Switzerland ; Gesundheitszentrum St Gallen, St Gallen, Switzerland
| | | | - Thomas Rosemann
- Institute of Primary Care, University of Zurich, Zurich, Switzerland
| | - Michael Stiefel
- Institute of Primary Care, University of Zurich, Zurich, Switzerland
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Saunders CJ, Posthumus M, O'Connell K, September AV, Collins M. A variant within the AQP1 3'-untranslated region is associated with running performance, but not weight changes, during an Ironman Triathlon. J Sports Sci 2014; 33:1342-8. [PMID: 25495276 DOI: 10.1080/02640414.2014.989535] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The objective of this study was to test the association of the rs1049305 (G > C) variant within the 3'-untranslated region of the aquaporin 1 gene, AQP1, with changes in body weight, post-race serum sodium concentration and performance in Ironman triathletes. Five hundred and four male Ironman triathletes were genotyped for the rs1049305 variant within the AQP1 gene. Change in pre- and post-race body weight was calculated for 470 triathletes and used as a proxy for changes in body fluid during the race, as well as to divide triathletes into biologically relevant weight-loss groups (0-3%, 3-5% and >5%). There were no rs1049305 genotype effects on post-race serum sodium concentrations (P = 0.647), pre-race weight (P = 0.610) nor relative weight change during the Ironman Triathlons (P = 0.705). In addition, there were no significant differences in genotype (P = 0.640) nor allele (P = 0.643) distributions between the weight loss groups. However, triathletes who carry a C-allele were found to complete the 42.2-km run stage faster (mean 286, s = 49 min) than triathletes with a GG genotype (mean 296, s = 47 min; P = 0.032). The AQP1 rs1049305 variant is associated with running performance, but not relative body weight change, during the 2000, 2001 and 2006 South African Ironman Triathlons.
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Affiliation(s)
- Colleen J Saunders
- a MRC/UCT Research Unit for Exercise Science and Sports Medicine of the Department of Human Biology, Faculty of Health Sciences , University of Cape Town, South Africa and the South African Medical Research Council , Cape Town , South Africa
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Hoffman MD, Stuempfle KJ. Hydration Strategies, Weight Change and Performance in a 161 km Ultramarathon. Res Sports Med 2014; 22:213-25. [PMID: 24950110 DOI: 10.1080/15438627.2014.915838] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- 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, USA
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Del Coso J, González C, Abian-Vicen J, Salinero Martín JJ, Soriano L, Areces F, Ruiz D, Gallo C, Lara B, Calleja-González J. Relationship between physiological parameters and performance during a half-ironman triathlon in the heat. J Sports Sci 2014; 32:1680-7. [PMID: 24825571 DOI: 10.1080/02640414.2014.915425] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Triathlon is a popular outdoor endurance sport performed under a variety of environmental conditions. The aim of this study was to assess physiological variables before and after a half-ironman triathlon in the heat and to analyse their relationship with performance. Thirty-four well-trained triathletes completed a half-ironman triathlon in a mean dry temperature of 29 ± 3ºC. Before and within 1 min after the end of the race, body mass, core temperature, maximal jump height and venous blood samples were obtained. Mean race time was 315 ± 40 min, with swimming (11 ± 1%), cycling (49 ± 2%) and running (40 ± 3%) representing different amounts of the total race time. At the end of the competition, body mass changed by -3.8 ± 1.6% and the change in body mass correlated positively with race time (r = 0.64; P < 0.001). Core temperature increased from 37.5 ± 0.6ºC to 38.8 ± 0.7ºC (P < 0.001) and post-race core temperature correlated negatively with race time (r = -0.47; P = 0.007). Race time correlated positively with the decrease in jump height (r = 0.38; P = 0.043), post-race serum creatine kinase (r = 0.55; P = 0.001) and myoglobin concentrations (r = 0.39; P = 0.022). In a half-ironman triathlon in the heat, greater reductions in body mass and higher post-competition core temperatures were present in faster triathletes. In contrast, slower triathletes presented higher levels of muscle damage and decreased muscle performance.
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Affiliation(s)
- Juan Del Coso
- a Sport Sciences Institute, Camilo José Cela University , Madrid , Spain
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Analysis of weight change and Borg rating of perceived exertion as measurements of runner health and safety during a 6-day, multistage, remote ultramarathon. Clin J Sport Med 2014; 24:245-50. [PMID: 24284951 DOI: 10.1097/jsm.0000000000000019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To determine the feasibility of using weight change and Borg score as tools for monitoring runner health and safety during a multistage, remote ultramarathon. DESIGN Observational cohort study of feasibility on nonblinded event participants. SETTING Six-day, multistage, remote ultramarathon in Utah. PARTICIPANTS Twenty-seven athletes in the 2012 Desert R.A.T.S. (Race Across the Sand) ultramarathon. ASSESSMENT OF RISK FACTORS Participant weight, health conditions that limited race participation, such as fatigue or exhaustion, and Borg score were reviewed. MAIN OUTCOME MEASURES Inability to complete a stage of the race (Did Not Finish status) or development of a clinically significant health condition during the race. Potential prognostic risk factors, such as a high Borg score and weight loss, were analyzed. RESULTS An overall decrease in weight was observed over the course of the event. Median percent weight changes were losses of 2.96% (day 1), 7.42% (day 2), 2.21% (day 4), and 3.35% (day 6). There was no statistically significant difference in percent weight change between the 14 runners who finished the race and the 13 runners who did not finish the race (U = 73; z = 0.189; P = 0.85). Runners' ability to complete the race was related to the development of adverse health conditions (P = 0.004). Median Borg scores reported were 15 (day 1), 17 (day 2), 13 (day 3), 16 (day 4), and 15 (day 6). Only 2 racers who finished the entire event without adverse events ever gave a Borg score of ≥ 18. CONCLUSIONS The feasibility of weight change as a tool for monitoring runner health and safety in this setting is limited, but the Borg rating of perceived exertion warrants further study as a potential field expedient tool for monitoring runner health and safety during a multiday, remote ultramarathon.
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Cosgrove SD, Love TD, Brown RC, Baker DF, Howe AS, Black KE. Fluid and Electrolyte Balance During Two Different Preseason Training Sessions in Elite Rugby Union Players. J Strength Cond Res 2014; 28:520-7. [DOI: 10.1519/jsc.0b013e3182986d43] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Hoffman MD, Hew-Butler T, Stuempfle KJ. Exercise-associated hyponatremia and hydration status in 161-km ultramarathoners. Med Sci Sports Exerc 2013; 45:784-91. [PMID: 23135369 DOI: 10.1249/mss.0b013e31827985a8] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
PURPOSE This work combines and reanalyzes 5 yr of exercise-associated hyponatremia (EAH) research at 161-km ultramarathons in northern California with primary purposes to define the relationship between postrace blood sodium concentration ([Na]) and change in body weight; to examine the interactions among EAH incidence, ambient temperature, and hydration state; and to explore the effect of hydration status on performance. METHODS Prerace and postrace body weight and finish time data were obtained on 887 finishers, and postrace [Na] was also obtained on a subset of 669 finishers. RESULTS EAH incidence was 15.1% overall (range, 4.6%-51.0% by year) and had a significant positive relationship with ambient temperature. Of the runners with EAH, 23.8% were classified as overhydrated (weight change, ≥0), 40.6% were euhydrated (weight change, <0% to -3%), and 35.6% were dehydrated (weight change, <-3%) at the finish. There was a weak significant relationship (r = 0.17, P < 0.0001) between postrace [Na] and change in body weight such that a lower [Na] was more common with increased weight loss. Considering all finishers examined, 18.5% were dehydrated and 34.9% were overhydrated at the finish. There was a weak significant relationship (r = 0.092, P = 0.006) between change in body weight and performance in that faster runners tended to lose more weight. Top finishers varied in body weight change from ∼1% gain to ∼6% loss. CONCLUSIONS EAH incidence can be high in 161-km ultramarathons in northern California. In this environment, EAH is more common with dehydration than overhydration and is more common in hotter ambient temperature conditions. Because weight loss >3% does not seem to have an adverse effect on performance, excessive sodium supplementation and aggressive fluid ingestion beyond the dictates of thirst are ill advised.
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Affiliation(s)
- Martin D Hoffman
- Department of Veterans Affairs, Northern California Health Care System, Mather, CA 95655-1200, USA.
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Bird SR, Linden M, Hawley JA. Acute changes to biomarkers as a consequence of prolonged strenuous running. Ann Clin Biochem 2013; 51:137-50. [PMID: 24000373 DOI: 10.1177/0004563213492147] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND A single bout of strenuous running exercise results in perturbations to numerous biomarkers. An understanding of these is important when analysing samples from individuals who have recently performed such exercise. METHODS A literature search was undertaken using the search terms, exercise, marathon and delayed onset of muscle soreness. The search was then refined using the terms for key biomarkers known to be altered by exercise. RESULTS The magnitude of changes to biomarkers is proportional to the severity of the running bout. Familiar, moderate intensity running exercise produces brief transient changes in common biomarkers such as lactate, whereas more severe bouts of running exercise, such as marathons and ultra-marathon events can produce changes to biomarkers that are normally associated with pathology of the muscles, liver and heart. Examples being changes to concentrations and/or activity of myoglobin, leucocytes, creatine kinase, bilirubin, cardiac troponins, lactate dehydrogenase, alanine aminotransferase and aspartate aminotransferase. While persisting for longer, these changes are also transient and full recovery occurs within days, without any apparent long-term adverse consequences. Additionally, unfamiliar exercise involving forceful eccentric muscle contractions, such as running downhill, can cause increases in creatine kinase and delayed onset of muscle soreness that peaks 36-72 h after the exercise bout. CONCLUSIONS Strenuous running exercise can produce changes to biomarkers that are normally associated with disease and injury, but these do not necessarily reflect chronic pathology.
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Affiliation(s)
- Stephen R Bird
- The Discipline of Exercise Sciences, School of Medical Sciences, RMIT University, Melbourne, Australia
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Rüst CA, Knechtle B, Knechtle P, Wirth A, Rosemann T. Body mass change and ultraendurance performance: a decrease in body mass is associated with an increased running speed in male 100-km ultramarathoners. J Strength Cond Res 2012; 26:1505-16. [PMID: 22614141 DOI: 10.1519/jsc.0b013e318231a7b5] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We investigated, in 50 recreational male ultrarunners, the changes in body mass, selected hematological and urine parameters, and fluid intake during a 100-km ultramarathon. The athletes lost (mean and SD) 2.6 (1.8) % in body mass (p < 0.0001). Running speed was significantly and negatively related to the change in body mass (p < 0.05). Serum sodium concentration ([Na⁺]) and the concentration of aldosterone increased with increasing loss in body mass (p < 0.05). Urine-specific gravity increased (p < 0.0001). The change in body mass was significantly and negatively related to postrace serum [Na⁺] (p < 0.05). Fluid intake was significantly and positively related to both running speed (r = 0.33, p = 0.0182) and the change in body mass (r = 0.44, p = 0.0014) and significantly and negatively to both postrace serum [Na⁺] (r = -0.42, p = 0.0022) and the change in serum [Na⁺] (r = -0.38, p = 0.0072). This field study showed that recreational, male, 100-km ultramarathoners dehydrated as evidenced by the decrease in >2 % body mass and the increase in urine-specific gravity. Race performance, however, was not impaired because of the loss in body mass. In contrast, faster athletes lost more body mass compared with slower athletes while also drinking more. The concept that a loss of >2% in body mass leads to dehydration and consequently impairs endurance performance must be questioned for ultraendurance athletes competing in the field. For practical applications, a loss in body mass during a 100-km ultramarathon was associated with a faster running speed.
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Affiliation(s)
- Christoph A Rüst
- Institute of General Practice and Health Services Research, University of Zurich, Zurich, Switzerland
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Mohseni M, Silvers S, McNeil R, Diehl N, Vadeboncoeur T, Taylor W, Shapiro S, Roth J, Mahoney S. Prevalence of hyponatremia, renal dysfunction, and other electrolyte abnormalities among runners before and after completing a marathon or half marathon. Sports Health 2012; 3:145-51. [PMID: 23016001 PMCID: PMC3445140 DOI: 10.1177/1941738111400561] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Background: Prior reports on metabolic derangements observed in distance running frequently have small sample sizes, lack prerace laboratory measures, and report sodium as the sole measure. Hypothesis: Metabolic abnormalities—hyponatremia, hypokalemia, renal dysfunction, hemoconcentration—are frequent after completing a full or half marathon. Clinically significant changes occur in these laboratory values after race completion. Study Design: Observational, cross-sectional study. Methods: Consenting marathon and half marathon racers completed a survey as well as finger stick blood sampling on race day of the National Marathon to Fight Breast Cancer (Jacksonville, Florida, February 2008). Parallel blood measures were obtained before and after race completion (prerace, n = 161; postrace, n = 195). Results: The prevalence of prerace and postrace hyponatremia was 8 of 161 (5.0%) and 16 of 195 (8.2%), respectively. Hypokalemia was not present prerace but was present in 1 runner postrace (1 of 195). Renal dysfunction occurred prerace in 14 of 161 (8.7%) and postrace in 83 of 195 (42.6%). Among those with postrace renal dysfunction, 45.8% (38 of 83) were classified as moderate or severe. Hemoconcentration was present in 2 of 161 (1.2%) prerace and 6 of 195 (3.1%) postrace. The mean changes in laboratory values were (postrace minus prerace): sodium, 1.6 mmol/L; potassium, −0.2 mmol/L; blood urea nitrogen, 2.8 mg/dL; creatinine, 0.2 mg/dL; and hemoglobin, 0.3 g/dL for 149 pairs (except blood urea nitrogen, n = 147 pairs). Changes were significant for all comparisons (P < 0.01) except potassium (P = 0.08) and hemoglobin (P = 0.01). Conclusions: Metabolic abnormalities are common among endurance racers, and they may be present prerace, including hyponatremia. The clinical significance of these findings is unknown. Clinical relevance: It is unclear which runners are at risk for developing clinically important metabolic derangements. Participating in prolonged endurance exercise appears to be safe in the majority of racers.
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Meyer M, Knechtle B, Bürge J, Knechtle P, Mrazek C, Wirth A, Ellenrieder B, Rüst CA, Rosemann T. Ad libitum fluid intake leads to no leg swelling in male Ironman triathletes - an observational field study. J Int Soc Sports Nutr 2012; 9:40. [PMID: 22937792 PMCID: PMC3524467 DOI: 10.1186/1550-2783-9-40] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Accepted: 08/30/2012] [Indexed: 11/10/2022] Open
Abstract
UNLABELLED BACKGROUND An association between fluid intake and limb swelling has been described for 100-km ultra-marathoners. We investigated a potential development of peripheral oedemata in Ironman triathletes competing over 3.8 km swimming, 180 km cycling and 42.2 km running. METHODS In 15 male Ironman triathletes, fluid intake, changes in body mass, fat mass, skeletal muscle mass, limb volumes and skinfold thickness were measured. Changes in renal function, parameters of skeletal muscle damage, hematologic parameters and osmolality in both serum and urine were determined. Skinfold thicknesses at hands and feet were measured using LIPOMETER® and changes of limb volumes were measured using plethysmography. RESULTS The athletes consumed a total of 8.6 ± 4.4 L of fluids, equal to 0.79 ± 0.43 L/h. Body mass, skeletal muscle mass and the volume of the lower leg decreased (p <0.05), fat mass, skinfold thicknesses and the volume of the arm remained unchanged (p >0.05). The decrease in skeletal muscle mass was associated with the decrease in body mass (p <0.05). The decrease in the lower leg volume was unrelated to fluid intake (p >0.05). Haemoglobin, haematocrit and serum sodium remained unchanged (p >0.05). Osmolality in serum and urine increased (p <0.05). The change in body mass was related to post-race serum sodium concentration ([Na+]) (r = -0.52, p <0.05) and post-race serum osmolality (r = -0.60, p <0.05). CONCLUSIONS In these Ironman triathletes, ad libitum fluid intake maintained plasma [Na+] and plasma osmolality and led to no peripheral oedemata. The volume of the lower leg decreased and the decrease was unrelated to fluid intake. Future studies may investigate ultra-triathletes competing in a Triple Iron triathlon over 11.4 km swimming, 540 km cycling and 126.6 km running to find an association between fluid intake and the development of peripheral oedemata.
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Affiliation(s)
- Michael Meyer
- Institute of Primary Care and Health Services Research, University of Zurich, Zurich, Switzerland.
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Schütz UHW, Schmidt-Trucksäss A, Knechtle B, Machann J, Wiedelbach H, Ehrhardt M, Freund W, Gröninger S, Brunner H, Schulze I, Brambs HJ, Billich C. The TransEurope FootRace Project: longitudinal data acquisition in a cluster randomized mobile MRI observational cohort study on 44 endurance runners at a 64-stage 4,486 km transcontinental ultramarathon. BMC Med 2012; 10:78. [PMID: 22812450 PMCID: PMC3409063 DOI: 10.1186/1741-7015-10-78] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Accepted: 07/19/2012] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND The TransEurope FootRace 2009 (TEFR09) was one of the longest transcontinental ultramarathons with an extreme endurance physical load of running nearly 4,500 km in 64 days. The aim of this study was to assess the wide spectrum of adaptive responses in humans regarding the different tissues, organs and functional systems being exposed to such chronic physical endurance load with limited time for regeneration and resulting negative energy balance. A detailed description of the TEFR project and its implemented measuring methods in relation to the hypotheses are presented. METHODS The most important research tool was a 1.5 Tesla magnetic resonance imaging (MRI) scanner mounted on a mobile unit following the ultra runners from stage to stage each day. Forty-four study volunteers (67% of the participants) were cluster randomized into two groups for MRI measurements (22 subjects each) according to the project protocol with its different research modules: musculoskeletal system, brain and pain perception, cardiovascular system, body composition, and oxidative stress and inflammation. Complementary to the diverse daily mobile MR-measurements on different topics (muscle and joint MRI, T2*-mapping of cartilage, MR-spectroscopy of muscles, functional MRI of the brain, cardiac and vascular cine MRI, whole body MRI) other methods were also used: ice-water pain test, psychometric questionnaires, bioelectrical impedance analysis (BIA), skinfold thickness and limb circumference measurements, daily urine samples, periodic blood samples and electrocardiograms (ECG). RESULTS Thirty volunteers (68%) reached the finish line at North Cape. The mean total race speed was 8.35 km/hour. Finishers invested 552 hours in total. The completion rate for planned MRI investigations was more than 95%: 741 MR-examinations with 2,637 MRI sequences (more than 200,000 picture data), 5,720 urine samples, 244 blood samples, 205 ECG, 1,018 BIA, 539 anthropological measurements and 150 psychological questionnaires. CONCLUSIONS This study demonstrates the feasibility of conducting a trial based centrally on mobile MR-measurements which were performed during ten weeks while crossing an entire continent. This article is the reference for contemporary result reports on the different scientific topics of the TEFR project, which may reveal additional new knowledge on the physiological and pathological processes of the functional systems on the organ, cellular and sub-cellular level at the limits of stress and strain of the human body. Please see related articles: http://www.biomedcentral.com/1741-7015/10/76 and http://www.biomedcentral.com/1741-7015/10/77.
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Affiliation(s)
- Uwe H W Schütz
- Department of Diagnostic and Interventional Radiology, University Hospital of Ulm, Germany.
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Abstract
CONTEXT Time allowing, euhydration can be achieved in the vast majority of individuals by drinking and eating normal beverages and meals. Important to the competitive athlete is prevention and treatment of dehydration and exercise-associated muscle cramps, as they are linked to a decline in athletic performance. Intravenous (IV) prehydration and rehydration has been proposed as an ergogenic aid to achieve euhydration more effectively and efficiently. EVIDENCE ACQUISITION PubMed database was searched in November 2011 for all English-language articles related to IV utilization in sport using the keywords intravenous, fluid requirements, rehydration, hydration, athlete, sport, exercise, volume expansion, and performance. RESULTS Limited evidence exists for prehydration with IV fluids. Although anecdotal evidence does exist, at this time there are no high-level studies confirming that IV prehydration prevents dehydration or the onset of exercise-associated muscle cramps. Currently, there are no published studies describing IV fluid use during the course of an event, at intermission, or after the event as an ergogenic aid. CONCLUSION The use of IV fluid may be beneficial for a subset of fluid-sensitive athletes; this should be reserved for high-level athletes with strong histories of symptoms in well-monitored settings. Volume expanders may also be beneficial for some athletes. IV fluids and plasma binders are not allowed in World Anti-Doping Agency-governed competitions. Routine IV therapy cannot be recommended as best practice for the majority of athletes.
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Knechtle B, Knechtle P, Wirth A, Alexander Rüst C, Rosemann T. A faster running speed is associated with a greater body weight loss in 100-km ultra-marathoners. J Sports Sci 2012; 30:1131-40. [PMID: 22668199 DOI: 10.1080/02640414.2012.692479] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
In 219 recreational male runners, we investigated changes in body mass, total body water, haematocrit, plasma sodium concentration ([Na(+)]), and urine specific gravity as well as fluid intake during a 100-km ultra-marathon. The athletes lost 1.9 kg (s = 1.4) of body mass, equal to 2.5% (s = 1.8) of body mass (P < 0.001), 0.7 kg (s = 1.0) of predicted skeletal muscle mass (P < 0.001), 0.2 kg (s = 1.3) of predicted fat mass (P < 0.05), and 0.9 L (s = 1.6) of predicted total body water (P < 0.001). Haematocrit decreased (P < 0.001), urine specific gravity (P < 0.001), plasma volume (P < 0.05), and plasma [Na(+)] (P < 0.05) all increased. Change in body mass was related to running speed (r = -0.16, P < 0.05), change in plasma volume was associated with change in plasma [Na(+)] (r = -0.28, P < 0.0001), and change in body mass was related to both change in plasma [Na(+)] (r = -0.36) and change in plasma volume (r = 0.31) (P < 0.0001). The athletes consumed 0.65 L (s = 0.27) fluid per hour. Fluid intake was related to both running speed (r = 0.42, P < 0.0001) and change in body mass (r = 0.23, P = 0.0006), but not post-race plasma [Na(+)] or change in plasma [Na(+)] (P > 0.05). In conclusion, faster runners lost more body mass, runners lost more body mass when they drank less fluid, and faster runners drank more fluid than slower runners.
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Affiliation(s)
- Beat Knechtle
- Facharzt FMH für Allgemeinmedizin, St. Gallen, Switzerland.
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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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Taylor NAS, van den Heuvel AMJ, Kerry P, McGhee S, Peoples GE, Brown MA, Patterson MJ. Observations on saliva osmolality during progressive dehydration and partial rehydration. Eur J Appl Physiol 2012; 112:3227-37. [PMID: 22230919 DOI: 10.1007/s00421-011-2299-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Accepted: 12/20/2011] [Indexed: 11/25/2022]
Abstract
A need exists to identify dehydrated individuals under stressful settings beyond the laboratory. A predictive index based on changes in saliva osmolality has been proposed, and its efficacy and sensitivity was appraised across mass (water) losses from 1 to 7%. Twelve euhydrated males [serum osmolality: 286.1 mOsm kg(-1) H(2)O (SD 4.3)] completed three exercise- and heat-induced dehydration trials (35.6°C, 56% relative humidity): 7% dehydration (6.15 h), 3% dehydration (with 60% fluid replacement: 2.37 h), repeat 7% dehydration (5.27 h). Expectorated saliva osmolality, measured at baseline and at each 1% mass change, was used to predict instantaneous hydration state relative to mass losses of 3 and 6%. Saliva osmolality increased linearly with dehydration, although its basal osmolality and its rate of change varied among and within subjects across trials. Receiver operating characteristic curves indicated a good predictive power for saliva osmolality when used with two, single-threshold cutoffs to differentiate between hydrated and dehydrated individuals (area under curve: 3% cutoff = 0.868, 6% cutoff = 0.831). However, when analysed using a double-threshold detection technique (3 and 6%), as might be used in a field-based monitor, <50% of the osmolality data could correctly identify individuals who exceeded 3% dehydration. Indeed, within the 3-6% dehydration range, its sensitivity was 64%, while beyond 6% dehydration, this fell to 42%. Therefore, while expectorated saliva osmolality tracked mass losses within individuals, its large intra- and inter-individual variability limited its predictive power and sensitivity, rendering its utility questionable within a universal dehydration monitor.
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Affiliation(s)
- Nigel A S Taylor
- Centre for Human and Applied Physiology, School of Health Sciences, University of Wollongong, Wollongong, NSW, 2522, Australia.
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Lopez RM, Casa DJ, Jensen KA, DeMartini JK, Pagnotta KD, Ruiz RC, Roti MW, Stearns RL, Armstrong LE, Maresh CM. Examining the Influence of Hydration Status on Physiological Responses and Running Speed During Trail Running in the Heat With Controlled Exercise Intensity. J Strength Cond Res 2011; 25:2944-54. [DOI: 10.1519/jsc.0b013e318231a6c8] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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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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Winger J. Sodium replacement and plasma sodium drop during exercise in the heat when fluid intake matches fluid loss. J Athl Train 2011; 45:547; author reply 548. [PMID: 21062176 DOI: 10.4085/1062-6050-45.6.547] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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No case of exercise-associated hyponatraemia in top male ultra-endurance cyclists: the ‘Swiss Cycling Marathon’. Eur J Appl Physiol 2011; 112:689-97. [DOI: 10.1007/s00421-011-2024-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2011] [Accepted: 05/23/2011] [Indexed: 10/18/2022]
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Laursen PB. Long distance triathlon: demands, preparation and performance. JOURNAL OF HUMAN SPORT AND EXERCISE 2011. [DOI: 10.4100/jhse.2011.62.05] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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Changes in total body water content during running races of 21.1 km and 56 km in athletes drinking ad libitum. Clin J Sport Med 2011; 21:218-25. [PMID: 21427566 DOI: 10.1097/jsm.0b013e31820eb8d7] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To measure changes in body mass (BM), total body water (TBW), fluid intake, and blood biochemistry in athletes during 21.1-km and 56-km foot races. DESIGN Observational study. SETTING 2009 Two Oceans Marathon, South Africa. PARTICIPANTS Twenty-one (21.1 km) and 12 (56 km) participants were advised to drink according to thirst or their own race drink plan (ad libitum). MAIN OUTCOME MEASURES Body mass, TBW, plasma osmolality, plasma sodium (p[Na]), and plasma total protein ([TP]) concentrations were measured before and after race. Fluid intake was recorded from recall after race. RESULTS Significant BM loss occurred in both races (21.1 km; -1.4 ± 0.6 kg; P < 0.000 and 56 km; -2.5 ± 1.1 kg; P < 0.000). Total body water was reduced in the 56-km race (-1.4 ± 1.1 kg; P < 0.001). A negative linear relationship was found between percentage change (%Δ) in TBW and %Δ in BM in the 56-km runners (r = 0.6; P < 0.01). Plasma osmolality and [TP] increased significantly in the 56-km runners (6.8 ± 8.2 mOsm/kg H2O; P < 0.05 and 5.4 ± 4.4 g/L; P < 0.01, respectively), but all other biochemical measures were within the normal range. CONCLUSIONS Although TBW decreased in the 56-km race and was maintained in the 21.1-km race, the change in TBW over both races was less than the BM, suggesting that not all BM lost during endurance exercise is a result purely of an equivalent reduction in TBW. These findings support the interpretation that the body primarily defends p[Na] and not BM during exercise and that a reduction in BM can occur without an equivalent reduction in TBW during prolonged exercise. Furthermore, these data support that drinking without controlling for BM loss may allow athletes to complete these events.
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Factors associated with a self-reported history of exercise-associated muscle cramps in Ironman triathletes: a case-control study. Clin J Sport Med 2011; 21:204-10. [PMID: 21430526 DOI: 10.1097/jsm.0b013e31820bcbfd] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Exercise-associated muscle cramping (EAMC) is a common medical condition in endurance athletes. The exact cause of and risk factors for EAMC are still being investigated. The main objective of this study was to investigate factors that are associated with a self-reported history of EAMC in Ironman triathletes. DESIGN Case-control study. SETTING Field study at an international Ironman Triathlon. PARTICIPANTS Triathletes participating in an Ironman Triathlon were recruited as subjects. ASSESSMENT OF RISK FACTORS A previously validated prerace questionnaire was completed by 433 subjects who were divided into subjects who reported a history of EAMC (EAMC group = 216) and those who no reported history of EAMC (CON group = 217). MAIN OUTCOME MEASURES Training, anthropometric, injury and performance, and other variables that were related to the history of EAMC. RESULTS Compared with the CON group, triathletes in the EAMC group were significantly taller and heavier, had faster Ironman race times despite being of similar caliber (past personal best times), and predicted and achieved a faster overall time during the Ironman Triathlon. There was an association among a positive family history for EAMC, a history of tendon and/or ligament injuries, and a self-reported history of EAMC. CONCLUSIONS There is evidence from this study that a history of EAMC is associated with (1) exercising at a higher intensity during a race that may result in premature muscle fatigue, (2) an inherited risk (positive family history), and (3) a history of tendon and/or ligament injury.
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Bonacci J, Green D, Saunders PU, Franettovich M, Blanch P, Vicenzino B. Plyometric training as an intervention to correct altered neuromotor control during running after cycling in triathletes: A preliminary randomised controlled trial. Phys Ther Sport 2011; 12:15-21. [DOI: 10.1016/j.ptsp.2010.10.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2010] [Revised: 10/16/2010] [Accepted: 10/19/2010] [Indexed: 10/18/2022]
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Knechtle B, Knechtle P, Rosemann T. Low prevalence of exercise-associated hyponatremia in male 100 km ultra-marathon runners in Switzerland. Eur J Appl Physiol 2010; 111:1007-16. [PMID: 21082192 DOI: 10.1007/s00421-010-1729-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/03/2010] [Indexed: 11/30/2022]
Abstract
We investigated the prevalence of exercise-associated hyponatremia (EAH) in 145 male ultra-marathoners at the '100-km ultra-run' in Biel, Switzerland. Changes in body mass, urinary specific gravity, haemoglobin, haematocrit, plasma [Na(+)], and plasma volume were determined. Seven runners (4.8%) developed asymptomatic EAH. Body mass, haematocrit and haemoglobin decreased, plasma [Na(+)] remained unchanged and plasma volume increased. Δ body mass correlated with both post race plasma [Na(+)] and Δ plasma [Na(+)]. Δ plasma volume was associated with post race plasma [Na(+)]. The athletes consumed 0.65 (0.30) L/h; fluid intake correlated significantly and negatively (r = -0.50, p < 0.0001) to race time. Fluid intake was neither associated with post race plasma [Na(+)] nor with Δ plasma [Na(+)], but was related to Δ body mass. To conclude, the prevalence of EAH was low at ~5% in these male 100 km ultra-marathoners. EAH was asymptomatic and would not have been detected without the measurement of plasma [Na(+)].
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Affiliation(s)
- Beat Knechtle
- Facharzt FMH für Allgemeinmedizin, Gesundheitszentrum St. Gallen, Vadianstrasse 26, 9001 St. Gallen, Switzerland.
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Abstract
OBJECTIVE Hyponatremia and the associated life-threatening complications have emerged as an important issue among marathon runners. This study was conducted to estimate the serum sodium level among local marathon runners and to identify the associated risk factors of dysnatremia. DESIGN Prospective observational cohort study. SETTING Hong Kong Marathon 2008. PARTICIPANTS Subjects were approached at their convenience to participate in the study. Only full-marathon runners were recruited. They were to have had an unremarkable medical and drug history. INTERVENTIONS Demographic data, training information, previous marathon experience, anticipated drinking strategy, details of fluid consumption throughout the race, weight change, finishing time, and physical complaint. MAIN OUTCOME MEASURES Post-race serum sodium level. RESULTS Of the 6488 entries to the race, 370 runners (5.7%) were recruited. Among them, 272 (73.5%) completed the race and attended for blood sampling and data collection. One runner (0.4%) had hyponatremia (133 mmol/L) and 35 runners (12.9%) had hypernatremia (>145 mmol/L), whereas 236 runners (86.7%) had normal serum sodium (135-145 mmol/L) after the race. No symptomatic dysnatremia was found. A mean weight reduction of 0.70 kg was found after the race. An average of 1.9 L of fluid was consumed during the race and 2.5 L if the fluid consumed immediately before and after the race was also included. Hypernatremia was seen in runners who were better trained before the race, those who performed better, and those who drank less water after the race. CONCLUSIONS This is the largest prospective observational cohort study of dysnatremia conducted on athletes completing a standard marathon in Asia. No case of symptomatic dysnatremia was found.
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Knechtle B, Knechtle P, Rosemann T, Oliver S. ATriple Iron triathlon leads to a decrease in total body mass but not to dehydration. RESEARCH QUARTERLY FOR EXERCISE AND SPORT 2010; 81:319-327. [PMID: 20949852 DOI: 10.1080/02701367.2010.10599680] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
A loss in total body mass during an ultraendurance performance is usually attributed to dehydration. We identified the changes in total body mass, fat mass, skeletal muscle mass, and selected markers of hydration status in 31 male nonprofessional ultratriathletes participating in a Triple Iron triathlon involving 11.4 km swimming, 540 km cycling and 126.6 km running. Measurements were taken prior to starting the race and after arrival at the finish line. Total body mass decreased by 1.66 kg (SD = 1.92; -5.3 kg to +1.2 kg; p < .001), skeletal muscle mass by 1.00 kg (SD = 0.90; -2.54 kg to +2.07 kg; p < .001), and fat mass by 0.58 kg (SD = 0.78; -1.74 kg to +0.87 kg; p < .001). The decrease in total body mass was associated with the decrease in skeletal muscle mass (r = .44; p < .05) and fat mass (r = .51; p < .05). Total body water and urinary specific gravity did not significantly change. Plasma urea increased significantly (p < .001); the decrease in skeletal muscle mass and the increase in plasma urea were associated (r = .39; p < .05). We conclude that completing a Triple Iron triathlon leads to decreased total body mass due to reduced fat mass and skeletal muscle mass but not to dehydration. The association of decrease in skeletal muscle mass and increased plasma urea suggests a loss in skeletal muscle mass.
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Osteocalcin as a negative regulator of serum leptin concentration in humans: insight from triathlon competitions. Eur J Appl Physiol 2010; 110:635-43. [DOI: 10.1007/s00421-010-1550-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/11/2010] [Indexed: 10/19/2022]
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Can changes in body mass and total body water accurately predict hyponatremia after a 161-km running race? Clin J Sport Med 2010; 20:193-9. [PMID: 20445360 DOI: 10.1097/jsm.0b013e3181da53ea] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To relate changes in body mass, total body water (TBW), extracellular fluid (ECF), and serum sodium concentration ([Na]) from a 161-km ultramarathon to finish time and incidence of hyponatremia. DESIGN Observational. SETTING : The 2008 Rio Del Lago 100-Mile (161-km) Endurance Run in Granite Bay, California. PARTICIPANTS Forty-five runners. MAIN OUTCOME MEASUREMENTS Pre-race and post-race body mass, TBW, ECF, and serum [Na]. RESULTS Body mass and serum [Na] significantly decreased 2% to 3% (P < 0.001) from pre-race to post-race, but TBW and ECF were unchanged. Significant relationships were observed between finish time and percentage change in body mass (r = 0.36; P = 0.01), TBW (r = 0.50; P = 0.007), and ECF (r = 0.61; P = 0.003). No associations were found between post-race serum [Na] and percentage change in body mass (r = -0.04; P = 0.94) or finish time (r = 0.5; P = 0.77). Hyponatremia (serum [Na] < 135 mmol/L) was present among 51.2% of finishers. Logistic regression prediction equation including pre-race TBW and percentage changes in TBW and ECF had an 87.5% concordance with the classification of hyponatremia. CONCLUSIONS Hyponatremia occurred in over half of the 161-km ultramarathon finishers but was not predicted by change in body mass. The combination of pre-race TBW and percentage changes in TBW and ECF explained 87.5% of the variation in the incidence of hyponatremia. CLINICAL SIGNIFICANCE Exercise-associated hyponatremia can occur simultaneously with dehydration and cannot be predicted by weight checks at races.
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Abstract
Exercise-associated hyponatremia (EAH) is hyponatremia that occurs <or= 24 hours after prolonged physical activity. It is a potentially serious complication of marathons, triathlons, and ultradistance events, and can occur in hot and cold environments. Clear evidence indicates that EAH is a dilutional hyponatremia caused by excessive fluid consumption and the inappropriate release of arginine vasopressin. Cerebral and pulmonary edema can cause serious signs and symptoms, including altered mental status, respiratory distress, seizures, coma, and death. Rapid diagnosis and urgent treatment with hypertonic saline is necessary to prevent severe complications or death. Prevention is based on educating athletes to avoid excessive drinking before, during, and after exercise.
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Affiliation(s)
- Kristin J Stuempfle
- Department of Health Sciences, Gettysburg College, Gettysburg, PA 17325, USA.
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van Rosendal SP, Osborne MA, Fassett RG, Lancashire B, Coombes JS. Intravenous versus Oral Rehydration in Athletes. Sports Med 2010; 40:327-46. [DOI: 10.2165/11319810-000000000-00000] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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Knechtle B, Wirth A, Baumann B, Knechtle P, Rosemann T. Personal best time, percent body fat, and training are differently associated with race time for male and female ironman triathletes. RESEARCH QUARTERLY FOR EXERCISE AND SPORT 2010; 81:62-68. [PMID: 20387399 DOI: 10.1080/02701367.2010.10599628] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We studied male and female nonprofessional Ironman triathletes to determine whether percent body fat, training, and/or previous race experience were associated with race performance. We used simple linear regression analysis, with total race time as the dependent variable, to investigate the relationship among athletes' percent body fat, average amount of weekly training, and best time in an Ironman triathlon. For male athletes, percent body fat (r2 = 0.57, p < .001) was related to total race time but not average weekly training. For women, percent body fat showed no association with total race time; howeven average weekly training volume was related to total race time (r = .43, p < .01). Percent body fat and average weekly training were not correlated in either gender Speed in training was not associated with race performance in either gender. For men (r2 = .56, p < .001) and women (r2 = .45, p < .05), personal best time in an Ironman triathlon was related to total race time. We concluded that percent body fat was related to race performance in male athletes and to average weekly training in female athletes. Personal best time in an Ironman triathlon was associated with total race time for both male and female athletes.
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Bike Transalp 2008: liquid intake and its effect on the body's fluid homeostasis in the course of a multistage, cross-country, MTB marathon race in the central Alps. Clin J Sport Med 2010; 20:47-52. [PMID: 20051734 DOI: 10.1097/jsm.0b013e3181c9673f] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVES To investigate the drinking behavior of the participants in a multi-day mountain bike (MTB) cross-country competition, to monitor its effect on the body's fluid compartments and body mass, and to evaluate the prevalence of exercise-associated dysnatremia. DESIGN Descriptive field study. SETTING The Jeantex Bike Transalp Competition 2008 (8 stages; 665.40 km; 21 691 m height). PARTICIPANTS Twenty-five male, amateur MTB cyclists. INDEPENDENT VARIABLES Reported fluid intake during the race, air temperature. MAIN OUTCOME MEASURES Changes in body mass and body composition from pre to post race and throughout the competition week, serum sodium concentration at finish line of stages 5 and 6. RESULTS Mean (+ or - SD) hourly fluid intake during the race correlated with air temperature (r = 0.868, P < .05) and ranged between 494 + or - 191 mL/h and 754 + or - 254 mL/h. In absence of exercise-induced hyponatremia (EAH) cases, we report 5 and 4 cases of asymptomatic post-race hypernatremia, on days 5 and 6, respectively. When related to race time and body mass, the liquid intake during the race (in mL x kg(-1) x h(-1)) correlated with post-race serum sodium concentration (stage 5: r = -0.463, P < .05, n = 24; stage 6: r = -0.589, P < .01, n = 23); no correlation was found between the change in body mass from pre to post race and serum sodium concentration at finish line. CONCLUSIONS Ad libitum fluid consumption during competition was spontaneously adjusted to the unsettled weather conditions in the course of the 2008 "Bike Transalp." The inverse linear relationship between hourly fluid intake and post-race serum sodium concentrations suggests underdrinking to be one contributing factor to the high reported incidence of hypernatremia in the absence of EAH. Experimental studies are requested to confirm this hypothesis and to further examine the pathogenesis of exercise-associated dysnatremia. In this setting, body mass monitoring was not an accurate instrument to control body fluid homeostasis.
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