1
|
Eifling KP, Gaudio FG, Dumke C, Lipman GS, Otten EM, Martin AD, Grissom CK. Wilderness Medical Society Clinical Practice Guidelines for the Prevention and Treatment of Heat Illness: 2024 Update. Wilderness Environ Med 2024; 35:112S-127S. [PMID: 38425235 DOI: 10.1177/10806032241227924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2024]
Abstract
The Wilderness Medical Society (WMS) convened an expert panel in 2011 to develop a set of evidence-based guidelines for the recognition, prevention, and treatment of heat illness. The current panel retained 5 original members and welcomed 2 new members, all of whom collaborated remotely to provide an updated review of the classifications, pathophysiology, evidence-based guidelines for planning and preventive measures, and recommendations for field- and hospital-based therapeutic management of heat illness. These recommendations are graded based on the quality of supporting evidence and the balance between the benefits and risks or burdens for each modality. This is an updated version of the WMS clinical practice guidelines for the prevention and treatment of heat illness published in Wilderness & Environmental Medicine. 2019;30(4):S33-S46.
Collapse
Affiliation(s)
- Kurt P Eifling
- Department of Emergency Medicine, University of Arkansas for Medical Sciences, Fayetteville, AR
| | - Flavio G Gaudio
- Department of Emergency Medicine, New York-Presbyterian Hospital / Weill Cornell Medical College, New York, NY
| | - Charles Dumke
- School of Integrative Physiology and Athletic Training, University of Montana, Missoula, MT
| | | | - Edward M Otten
- Department of Emergency Medicine, University of Cincinnati, Cincinnati, OH
| | - August D Martin
- Department of Internal Medicine, University of Arkansas for Medical Sciences, Fayetteville, AR
| | - Colin K Grissom
- Pulmonary and Critical Care Division, Intermountain Medical Center and the University of Utah, Salt Lake City, UT
| |
Collapse
|
2
|
Lipman GS, Gaudio FG, Eifling KP, Ellis MA, Otten EM, Grissom CK. Wilderness Medical Society Clinical Practice Guidelines for the Prevention and Treatment of Heat Illness: 2019 Update. Wilderness Environ Med 2019; 30:S33-S46. [DOI: 10.1016/j.wem.2018.10.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Revised: 09/04/2018] [Accepted: 10/22/2018] [Indexed: 10/26/2022]
|
3
|
McCartney D, Desbrow B, Irwin C. The Effect of Fluid Intake Following Dehydration on Subsequent Athletic and Cognitive Performance: a Systematic Review and Meta-analysis. SPORTS MEDICINE-OPEN 2017; 3:13. [PMID: 28316054 PMCID: PMC5357466 DOI: 10.1186/s40798-017-0079-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Accepted: 02/28/2017] [Indexed: 01/08/2023]
Abstract
Background The deleterious effects of dehydration on athletic and cognitive performance have been well documented. As such, dehydrated individuals are advised to consume fluid in volumes equivalent to 1.25 to 1.5 L kg−1 body mass (BM) lost to restore body water content. However, individuals undertaking subsequent activity may have limited time to consume fluid. Within this context, the impact of fluid intake practices is unclear. This systematic review investigated the effect of fluid consumption following a period of dehydration on subsequent athletic and cognitive performance. Methods PubMed (MEDLINE), Web of Science (via Thomas Reuters) and Scopus databases were searched for articles reporting on athletic (categorized as: continuous, intermittent, resistance, sport-specific and balance exercise) or cognitive performance following dehydration of participants under control (no fluid) and intervention (fluid intake) conditions. Meta-analytic procedures determined intervention efficacy for continuous exercise performance. Results Sixty-four trials (n = 643 participants) derived from 42 publications were reviewed. Dehydration decreased BM by 1.3–4.2%, and fluid intake was equivalent to 0.4–1.55 L kg−1 BM lost. Fluid intake significantly improved continuous exercise performance (22 trials), Hedges’ g = 0.46, 95% CI 0.32, 0.61. Improvement was greatest when exercise was performed in hotter environments and over longer durations. The volume or timing of fluid consumption did not influence the magnitude of this effect. Evidence indicating a benefit of fluid intake on intermittent (10 trials), resistance (9 trials), sport-specific (6 trials) and balance (2 trials) exercise and on cognitive performance (15 trials) was less apparent and requires further elucidation. Conclusions Fluid consumption following dehydration may improve continuous exercise performance under heat stress conditions, even when the body water deficit is modest and fluid intake is inadequate for complete rehydration. Electronic supplementary material The online version of this article (doi:10.1186/s40798-017-0079-y) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Danielle McCartney
- School of Allied Health Sciences and Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia.
| | - Ben Desbrow
- School of Allied Health Sciences and Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia
| | - Christopher Irwin
- School of Allied Health Sciences and Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia
| |
Collapse
|
4
|
Arnaoutis G, Kavouras SA, Stratakis N, Likka M, Mitrakou A, Papamichael C, Sidossis LS, Stamatelopoulos K. The effect of hypohydration on endothelial function in young healthy adults. Eur J Nutr 2016; 56:1211-1217. [PMID: 26864199 DOI: 10.1007/s00394-016-1170-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 01/29/2016] [Indexed: 11/25/2022]
Abstract
PURPOSE Hypohydration has been suggested as a predisposing factor for several pathologies including cardiovascular diseases (CVD). While CVD are the leading cause of death worldwide, no study has investigated whether acute hypohydration affects endothelial function and cardiovascular function. METHODS Ten young, healthy males participated in this crossover study (age: 24.3 ± 2.3 year; weight: 80.8 ± 5.3 kg; BMI: 24.3 ± 0.4 kg m-2). Each subject completed two measurements of endothelial function by flow-mediated dilation (FMD) in euhydrated and hypohydrated state separated by 24 h. Following baseline assessment of hydration status and FMD, the subjects completed 100 min of low-intensity intermittent walking exercise to achieve hypohydration of -2 % of individual body mass. For the rest of the day, a standardized, low water content diet was provided. The following morning, hydration markers and endothelial function were recorded. RESULTS Hypohydration by -1.9 ± 0.1 % of body mass resulted in decreased plasma volume by -3.5 ± 1.8 % and increased plasma osmolality by 9 ± 2 mmol kg-1 (P < 0.001). FMD as a response to hypohydration decreased by -26.8 ± 3.9 % (P < 0.05). CONCLUSION The data suggested that a small degree of hypohydration induced by moderate exercise and fluid restriction significantly impaired endothelial function.
Collapse
Affiliation(s)
- Giannis Arnaoutis
- Department of Nutrition and Dietetics, Harokopio University, Athens, Greece
| | - Stavros A Kavouras
- Department of Health, Human Performance and Recreation, University of Arkansas, Fayetteville, AR, 72701, USA.
| | - Nikolaos Stratakis
- Department of Nutrition and Dietetics, Harokopio University, Athens, Greece
| | - Marita Likka
- Vascular Laboratory, Department of Clinical Therapeutics, Alexandra University Hospital, Athens, Greece
| | - Asimina Mitrakou
- Vascular Laboratory, Department of Clinical Therapeutics, Alexandra University Hospital, Athens, Greece
| | - Christos Papamichael
- Vascular Laboratory, Department of Clinical Therapeutics, Alexandra University Hospital, Athens, Greece
| | - Labros S Sidossis
- Department of Nutrition and Dietetics, Harokopio University, Athens, Greece.,Department of Exercise Science and Sports Studies, Department of Medicine, Robert Wood Johnson Medical School, Rutgers University, New Jersey, USA
| | - Kimon Stamatelopoulos
- Vascular Laboratory, Department of Clinical Therapeutics, Alexandra University Hospital, Athens, Greece
| |
Collapse
|
5
|
|
6
|
Lipman GS, Eifling KP, Ellis MA, Gaudio FG, Otten EM, Grissom CK. Wilderness Medical Society practice guidelines for the prevention and treatment of heat-related illness: 2014 update. Wilderness Environ Med 2015; 25:S55-65. [PMID: 25498263 DOI: 10.1016/j.wem.2014.07.017] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Revised: 06/26/2014] [Accepted: 07/01/2014] [Indexed: 11/29/2022]
Abstract
The Wilderness Medical Society (WMS) convened an expert panel to develop a set of evidence-based guidelines for the recognition, prevention, and treatment of heat illness. We present a review of the classifications, pathophysiology, and evidence-based guidelines for planning and preventive measures as well as best practice recommendations for both field and hospital-based therapeutic management of heat illness. These recommendations are graded on the basis of the quality of supporting evidence, and balance between the benefits and risks or burdens for each modality. This is an updated version of the original WMS Practice Guidelines for the Prevention and Treatment of Heat-Related Illness published in Wilderness & Environmental Medicine 2013;24(4):351-361.
Collapse
Affiliation(s)
- Grant S Lipman
- Division of Emergency Medicine, Stanford University School of Medicine, Stanford, CA (Dr Lipman).
| | - Kurt P Eifling
- Division of Emergency Medicine, Barnes-Jewish Hospital/Washington University School of Medicine, Saint Louis, MO (Dr Eifling)
| | - Mark A Ellis
- Department of Emergency Medicine, Spartanburg Regional Healthcare System, Spartanburg, SC (Dr Eifling)
| | - Flavio G Gaudio
- Division of Emergency Medicine, New York-Presbyterian Hospital/Weill Cornell Medical College, New York, NY (Dr Gaudio)
| | - Edward M Otten
- Department of Emergency Medicine, University of Cincinnati, Cincinnati, OH (Dr Otten)
| | - Colin K Grissom
- Pulmonary and Critical Care Division, Intermountain Medical Center and the University of Utah, Salt Lake City, UT (Dr Grissom)
| | | |
Collapse
|
7
|
Abstract
The objective of this article is to provide a review of the fundamental aspects of body fluid balance and the physiological consequences of water imbalances, as well as discuss considerations for the optimal composition of a fluid replacement beverage across a broad range of applications. Early pioneering research involving fluid replacement in persons suffering from diarrheal disease and in military, occupational, and athlete populations incurring exercise- and/or heat-induced sweat losses has provided much of the insight regarding basic principles on beverage palatability, voluntary fluid intake, fluid absorption, and fluid retention. We review this work and also discuss more recent advances in the understanding of fluid replacement as it applies to various populations (military, athletes, occupational, men, women, children, and older adults) and situations (pathophysiological factors, spaceflight, bed rest, long plane flights, heat stress, altitude/cold exposure, and recreational exercise). We discuss how beverage carbohydrate and electrolytes impact fluid replacement. We also discuss nutrients and compounds that are often included in fluid-replacement beverages to augment physiological functions unrelated to hydration, such as the provision of energy. The optimal composition of a fluid-replacement beverage depends upon the source of the fluid loss, whether from sweat, urine, respiration, or diarrhea/vomiting. It is also apparent that the optimal fluid-replacement beverage is one that is customized according to specific physiological needs, environmental conditions, desired benefits, and individual characteristics and taste preferences.
Collapse
|
8
|
Burke LM, Maughan RJ. The Governor has a sweet tooth - mouth sensing of nutrients to enhance sports performance. Eur J Sport Sci 2014; 15:29-40. [PMID: 25345670 DOI: 10.1080/17461391.2014.971880] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The oral-pharyngeal cavity and the gastrointestinal tract are richly endowed with receptors that respond to taste, temperature and to a wide range of specific nutrient and non-nutritive food components. Ingestion of carbohydrate-containing drinks has been shown to enhance endurance exercise performance, and these responses have been attributed to post-absorptive effects. It is increasingly recognised, though, that the response to ingested carbohydrate begins in the mouth via specific carbohydrate receptors and continues in the gut via the release of a range of hormones that influence substrate metabolism. Cold drinks can also enhance performance, especially in conditions of thermal stress, and part of the mechanism underlying this effect may be the response to cold fluids in the mouth. There is also some, albeit not entirely consistent, evidence for effects of caffeine, quinine, menthol and acetic acid on performance or other relevant effects. This review summarises current knowledge of responses to mouth sensing of temperature, carbohydrate and other food components, with the goal of assisting athletes to implement practical strategies that make best use of its effects. It also examines the evidence that oral intake of other nutrients or characteristics associated with food/fluid intake during exercise can enhance performance via communication between the mouth/gut and the brain.
Collapse
Affiliation(s)
- Louise M Burke
- a Sports Nutrition , Australian Institute of Sport , Belconnen , ACT 2616 , Australia
| | | |
Collapse
|
9
|
Lipman GS, Eifling KP, Ellis MA, Gaudio FG, Otten EM, Grissom CK. Wilderness Medical Society Practice Guidelines for the Prevention and Treatment of Heat-Related Illness. Wilderness Environ Med 2013; 24:351-61. [DOI: 10.1016/j.wem.2013.07.004] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Revised: 07/09/2013] [Accepted: 07/09/2013] [Indexed: 11/16/2022]
|
10
|
The use of pregame hyperhydration with intravenous fluids in National Collegiate Athletic Association Football Bowl Subdivision teams. Clin J Sport Med 2013; 23:488-90. [PMID: 23391988 DOI: 10.1097/jsm.0b013e31828563b2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To determine the frequency of pregame intravenous fluid hyperhydration (PIVFH) usage, administration protocols, indications, complications, and perceived efficacy by National Collegiate Athletic Association Football Bowl Subdivision (NCAA-FBS) teams. DESIGN Cross-sectional survey study. SETTING National Collegiate Athletic Association Football Bowl Subdivision. PARTICIPANTS Head athletic trainers from NCAA-FBS institutions. INTERVENTION Voluntary, anonymous 15-item validated online survey instrument. MAIN OUTCOME MEASURES Number of teams reporting use of PIVFH. RESULTS The survey response rate was 64% (77 of 120). Thirty percent of respondents reported the utilization of PIVFH, administered to an average of 2 to 3 players. The most common reasons cited for using PIVFH were to prevent muscle cramps (95%), heat illness (79%), and dehydration (68%). Additionally, 47% of programs used PIVFH to improve player exercise tolerance and 47% per player request. Twenty-four percent of programs that used PIVFH reported the occurrence of associated complications. Only 15% of respondents believed that PIVFH improved their teams' overall performance. CONCLUSIONS PIVFH is a common practice among NCAA-FBS teams. PIVFH is used most often to prevent muscle cramps, dehydration, and heat illness. The relatively few numbers of players per team who receive PIVFH suggest that higher risk individuals were targeted for administration.
Collapse
|
11
|
Wall BA, Watson G, Peiffer JJ, Abbiss CR, Siegel R, Laursen PB. Current hydration guidelines are erroneous: dehydration does not impair exercise performance in the heat. Br J Sports Med 2013; 49:1077-83. [DOI: 10.1136/bjsports-2013-092417] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/29/2013] [Indexed: 11/04/2022]
|
12
|
Van Rosendal SP, Strobel NA, Osborne MA, Fassett RG, Coombes JS. Performance benefits of rehydration with intravenous fluid and oral glycerol. Med Sci Sports Exerc 2013; 44:1780-90. [PMID: 22453248 DOI: 10.1249/mss.0b013e31825420f4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE Intravenous (IV) saline has been used by athletes attempting to accelerate rehydration procedures. The diuresis from IV rehydration may be circumvented through the concomitant use of oral glycerol. We aimed to examine the effects of rehydrating with four different regimens of IV fluid and oral glycerol on subsequent 40-km cycling time trial performance. METHODS Nine endurance-trained men were dehydrated by 4% bodyweight via exercise in the heat. They then rehydrated with 150% of the fluid lost via four protocols using a randomized crossover design: 1) oral = sports drink and water; 2) oral glycerol = sports drink, water, and glycerol; 3) IV = half as normal saline, half of sports drink, and water; and 4) IV with oral glycerol = half as normal saline, half as sports drink, water, and glycerol. After this, they completed a 40-km cycling performance test in the heat. RESULTS Compared with oral rehydration, there were significant performance benefits (P < 0.05) when rehydrating with oral glycerol (improved time to complete 40 km by 3.7%), IV (3.5%), and IV with oral glycerol (4.1%). Plasma volume restoration was highest in IV with oral glycerol, then IV, then oral glycerol, then oral (P < 0.01 for all of these comparisons). There were no differences in HR, tympanic/skin temperatures, sweat rate, blood lactate concentration, thermal stress, or RPE between groups. CONCLUSIONS Combining IV fluid with oral glycerol resulted in the greatest fluid retention; however, it did not improve exercise performance compared with either modality alone.
Collapse
Affiliation(s)
- Simon P Van Rosendal
- Human Performance Laboratory, School of Human Movement Studies, The University of Queensland, Brisbane, Queensland, Australia
| | | | | | | | | |
Collapse
|
13
|
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.
Collapse
|
14
|
|
15
|
Seventy-five percent of National Football League teams use pregame hyperhydration with intravenous fluid. Clin J Sport Med 2011; 21:192-9. [PMID: 21499081 DOI: 10.1097/jsm.0b013e31820f3612] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVE To determine the number of National Football League (NFL) teams using pregame hyperhydration with intravenous fluid (IVF), the most common protocols for using the IVF, the complications from this routine, and the perceived efficacy of this treatment. DESIGN Cross-sectional survey study. SETTING National Football League. PARTICIPANTS The head athletic trainer from all 32 NFL teams received and completed the survey. INTERVENTION A survey designed to answer the aforementioned topics. MAIN OUTCOME MEASURES Number of teams using IVF to hyperhydrate euvolemic players before NFL games. RESULTS All teams (100%, 32 of 32) responded. Seventy-five percent (24 of 32) of NFL teams used pregame hyperhydration with IVF. On average, 5 to 7 players per team per game received IVF. Players received an average of 1.5 L of fluid, an average of 2.5 hours before the game. When the athletic trainers were asked to mark all the reasons why they use pregame hyperhydration with IVF, the most commonly cited reason was muscle cramps (23 of 24). However, player request was the number one answer (10 of 24) when the athletic trainers were asked to mark only the primary reason for giving IVF. Of the 27 head athletic trainers who had used pregame hyperhydration with IVF in the past, 13 (48%) reported complications. CONCLUSIONS Pregame hyperhydration is a common practice in the NFL. Because pregame hyperhydration with IVF is often a player- driven routine and has potential complications, more scientific studies are needed to determine its true efficacy.
Collapse
|
16
|
Hostler D, Bednez JC, Kerin S, Reis SE, Kong PW, Morley J, Gallagher M, Suyama J. Comparison of rehydration regimens for rehabilitation of firefighters performing heavy exercise in thermal protective clothing: a report from the fireground rehab evaluation (FIRE) trial. PREHOSP EMERG CARE 2010; 14:194-201. [PMID: 20095824 DOI: 10.3109/10903120903524963] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Performing fire suppression activities results in cardiovascular stress, hyperthermia, and hypohydration. Fireground rehabilitation (rehab) is recommended to blunt the deleterious effects of these conditions. OBJECTIVE We tested the hypothesis that three rehydration fluids provided after exercise while wearing thermal protective clothing (TPC) would produce different heart rate or core temperature responses during a second bout of exercise in TPC. METHODS On three occasions, 18 euhydrated firefighters (16 men, two women) wearing TPC completed a standardized, 50-minute bout of upper and lower body exercise in a hot room that mimicked the National Fire Protection Association (NFPA) rehabilitation guidelines of "two cylinders before rehab" (20 minutes of work, 10 minutes of recovery, 20 minutes of work). After an initial bout of exercise (bout 1), subjects were randomly assigned water, sport drink, or an intravenous (IV) infusion of normal saline equal to the amount of body mass lost during exercise. After rehydration, the subject performed a second bout of exercise (bout 2). Heart rates, core and skin temperatures, and exercise durations were compared with a two-way analysis of variance (ANOVA). RESULTS Subjects were firefighters with a mean (+/- standard deviation [SD]) age of 28.2 +/- 11.3 years and a mean peak oxygen consumption (VO(2peak)) of 37.4 +/- 3.4 mL/kg/min. The mean amount of fluid provided during the rehabilitation period was 527 +/- 302 mL. No subject could complete either the pre- or postrehydration 50-minute bout of exercise. The mean (+/-SD) times to exhaustion were longer (p < 0.001) in bout 1 (25.9 +/- 12.9 min, water; 28.0 +/- 14.1 min, sport drink; 27.4 +/- 13.8 min, IV) compared with bout 2 (15.6 +/- 9.6 min, water; 14.7 +/- 8.6 min, sport drink; 15.7 +/- 8.0 min, IV) for all groups but did not differ by intervention. All subjects approached their age-predicted maximum heart rate at the end of bout 1 (180 +/- 11 bpm) and bout 2 (176 +/- 13 bpm). Core temperature rose 1.1 degrees C +/- 0.7 degrees C during bout 1 and 0.5 degrees C +/- 0.4 degrees C during bout 2. Core temperatures, heart rates, and exercise times during bout 2 did not differ between the rehydration fluids. CONCLUSIONS Performances during a second bout of exercise in TPC did not differ when firefighters were rehydrated with water, sport drink, or IV normal saline when full rehydration was provided. Of concern was the inability of all subjects to complete two consecutive periods of heavy exercise in TPC, suggesting that the NFPA's "two cylinders before rehab" guideline may not be appropriate in continuous heavy work scenarios.
Collapse
Affiliation(s)
- David Hostler
- Department of Emergency Medicine, Emergency Responder Human Performance Laboratory, University of Pittsburgh, Pittsburgh, Pennsylvania 15213, USA.
| | | | | | | | | | | | | | | |
Collapse
|
17
|
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]
|
18
|
Beasley KN, Lee EC, McDermott BP, Yamamoto LM, Emmanuel H, Casa DJ, Armstrong LE, Kraemer WJ, Maresh CM. The effect of oral vs. Intravenous rehydration on circulating myoglobin and creatine kinase. J Strength Cond Res 2010; 24:60-7. [PMID: 20042925 DOI: 10.1519/jsc.0b013e3181c63c4e] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Physical activity of significant intensity and duration may cause varying degrees of skeletal muscle damage, but it is unclear whether mode of rehydration will attenuate muscle tissue disruption caused by exercise in the heat. To examine the effects of the mode of rehydration on markers of muscle damage (myoglobin and creatine kinase [CK]), 11 healthy active men (age = 23 +/- 4 years, body mass = 80.9 +/- 3.9 kg, height = 180.5 +/- 5.4 cm) completed 4 experimental trials consisting of an exercise dehydration protocol (to -4% of baseline body mass), followed by a rehydration period (oral, intravenous [IV], oral and IV combined, and ad libitum), and finishing with an intense exercise challenge that included treadmill running and sprinting and a box lifting protocol. During rehydration, subjects returned to -2% of baseline body mass unless completing the ad libitum trial during which they consumed fluids as thirst dictated. Myoglobin (Mb) and CK were measured during euhydrated rest. Post-exercise blood was drawn at 1 and 24 hours post exercise challenge for Mb and CK, respectively. Urine was collected during euhydrated rest and 1-hour post exercise challenge for measurement of Mb clearance. Mb concentrations increased significantly from pre (1.06 +/- 0.20, 0.88 +/- 0.07, 1.15 +/- 0.25 and 0.92 +/- 0.06 nmol.L) to post (1.52 +/- 0.28, 1.44 +/- 0.11, 1.71 +/- 0.45 and 1.58 +/- 0.39) for IV, oral, oral and IV combined, and ad libitum, respectively, but were not significantly different among trials. Serum CK concentrations remained within the normal physiological range for all trials. Thus, despite previous research that clearly indicates the benefit of ingesting fluids during exercise to attenuate muscle damage, there were no significant differences between the modes of rehydration on circulating Mb and CK.
Collapse
Affiliation(s)
- Kathleen N Beasley
- Department of Kinesiology, University of Connecticut, Storrs, Connecticut, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Hostler D, Gallagher M, Goss FL, Seitz JR, Reis SE, Robertson RJ, Northington WE, Suyama J. The effect of hyperhydration on physiological and perceived strain during treadmill exercise in personal protective equipment. Eur J Appl Physiol 2008; 105:607-13. [PMID: 19037655 DOI: 10.1007/s00421-008-0940-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/10/2008] [Indexed: 11/25/2022]
Abstract
Work in personal protective equipment (PPE) impairs thermoregulation causing cardiovascular stress, increased core body temperature, and hypohydration. We examined the effect of pretreating first responders performing treadmill exercise in PPE with an infusion of normal saline on physiological and perceptual strain. Ten (eight males, two females) euhydrated subjects performed treadmill exercise on two occasions wearing a chemical resistant coverall, air purifying respirator, butyl gloves, and heavy boots. During the hyperhydration session, normal saline was rapidly infused through an arm vein prior to donning PPE. Exercise duration and maximum core temperature did not differ between euhydrated and hyperhydrated conditions. Perceptual strain index (PeSI) was higher than physiological strain index (PhSI) in the euhydrated condition (P = 0.002) but neither index differed between the control and experimental conditions. Intravenous hyperhydration did not reduce physiological stress, increase exercise, or influence perceptual strain time when compared to the euhydrated condition in moderately fit individuals.
Collapse
Affiliation(s)
- David Hostler
- Emergency Responder Human Performance Lab, Department of Emergency Medicine, University of Pittsburgh, 230 McKee Place, Suite 400, Pittsburgh, PA 15213, USA.
| | | | | | | | | | | | | | | |
Collapse
|
20
|
Casa DJ, Ganio MS, Lopez RM, McDermott BP, Armstrong LE, Maresh CM. Intravenous versus Oral Rehydration. Curr Sports Med Rep 2008. [DOI: 10.1249/jsr.0b013e31817f3e85] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
21
|
Abstract
OBJECTIVE To determine if a return to normonatremia is required for symptomatology to resolve in collapsed hypernatremic runners and if intravenous (IV) administration of an isotonic solution would adversely affect serum sodium concentration ([Na+]) in collapsed normonatremic runners. DESIGN Observational study. SETTING 2006 Comrades Marathon. PARTICIPANTS 103 collapsed runners. MAIN OUTCOME MEASURE Final serum [Na] upon discharge. RESULTS 58% of all collapsed runners were hypernatremic. Hypernatremic runners reported significantly more vomiting than normonatremic runners (79 versus 34%; P < 0.001). A significant decrease in serum [Na] in hypernatremic collapsed runners occurred after the IV administration of either 1 L of 0.45% normal saline (150.5 +/- 3.5 versus 148.0 +/- 4.6; P < 0.05) or Ringers lactate solution (147.7 +/- 2.2 versus 146.2 +/- 2.1; P < 0.05). One liter of IV fluid administration caused an increase in plasma volume that was not significantly different between (1) hypernatremic runners receiving a hypotonic solution (13.5 +/- 12.7%) and (2) normonatremic runners receiving an isotonic solution (15.6 +/- 11.3%). The final serum [Na+] of hypernatremic runners was above the range for normonatremia upon discharge (>145 mmol/L). CONCLUSIONS A return to normonatremia was not required for hypernatremic runners to "recover" and be discharged from the medical tent. Vomiting either aggravated and/or facilitated the development of hypernatremia. IV administration of 1 L of either (1) a hypotonic solution to hypernatremic runners or (2) an isotonic solution to both normonatremic and hypernatremic runners did not produce any adverse biochemical or cardiovascular changes and can therefore be considered a safe and effective treatment for collapsed runners if used in this context.
Collapse
|
22
|
Ganio MS, Casa DJ, Armstrong LE, Maresh CM. Evidence-Based Approach to Lingering Hydration Questions. Clin Sports Med 2007; 26:1-16. [PMID: 17241912 DOI: 10.1016/j.csm.2006.11.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Studies related to fundamental hydration issues have required clinicians to re-examine certain practices and concepts. The ingestion of substances such as creatine, caffeine, and glycerol has been questioned in regards to safety and hydration status. Reports of overdrinking (hyponatremia) also have brought into question the practices of drinking appropriate fluid amounts and the role that fluid-electrolyte balance has in the etiology of heat illnesses such as heat cramps. This article offers a fresh perspective on timely topics related to hydration, fluid balance, and exercise in the heat.
Collapse
Affiliation(s)
- Matthew S Ganio
- Human Performance Laboratory, Department of Kinesiology, University of Connecticut, 2095 Hillside Road, U-1110, Storrs, CT 06269-1110, USA
| | | | | | | |
Collapse
|
23
|
Abstract
PURPOSE This study sought to determine the effect of rapid intravenous (IV) versus oral (ORAL) rehydration immediately after dehydration, on cardiovascular, thermoregulatory, and perceptual responses during subsequent exercise in the heat. METHODS Eight males (21.4 +/- 0.7 yr; 176.2 +/- 1.6 cm; 75.2 +/- 3.7 kg; 63.7 +/- 3.6 mL.kg.min VO2max, 9.0 +/- 1.7% fat) participated in three randomized trials. Each trial consisted of a 75-min dehydration phase (36 degrees C; 42.5% rh, 47 +/- 0.9% VO2max) where subjects lost 1.7 L (IV and no-fluid (NF) trials) to 1.8 L of fluid (ORAL trial). In the heat, fluid lost was matched with 0.45% saline in 20 min by either IV or ORAL rehydration; no fluid was given in the NF trial. Subjects then performed a heat-tolerance test (HTT; 37.0 degrees C, 45% rh, treadmill speed of 2.4 m.s, 2.3% grade) for 75 min or until exhaustion (Tre of 39.5 degrees C). During the HTT, thermal and thirst sensations, RPE, rectal temperature (Tre), heart rate (HR), and mean weighted skin temperature (Tsk) were measured. RESULTS Plasma volume in the IV treatment was greater (P < 0.05) after rehydration compared with ORAL and NF. However, during the HTT there were no overall differences (P > 0.05) in HR, Tre, Tsk, RPE, thermal sensations, or HTT time (ORAL, 71 +/- 8 min; IV, 73 +/- 5 min; NF, 39 +/- 29 min) between the ORAL and IV treatments. Sensations of thirst were lower (P < 0.05) in ORAL compared with IV and NF, likely because of oropharyngeal stimuli. CONCLUSIONS Despite a more rapid restoration of plasma volume, IV rehydration was not advantageous over ORAL rehydration in regards to physiological strain, heat tolerance, RPE, or thermal sensations.
Collapse
Affiliation(s)
- Robert W Kenefick
- U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760, USA.
| | | | | | | |
Collapse
|
24
|
Maresh CM, Herrera-Soto JA, Armstrong LE, Casa DJ, Kavouras SA, Hacker FT, Elliott TA, Stoppani J, Scheett TP. Perceptual responses in the heat after brief intravenous versus oral rehydration. Med Sci Sports Exerc 2001; 33:1039-45. [PMID: 11404671 DOI: 10.1097/00005768-200106000-00025] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE The purpose of the study was to compare the effects of a brief period (20 min) of intravenous (IV) fluid rehydration and oral (ORAL) rehydration on ratings of perceived exertion (RPE), thirst, and thermal sensation (TS) during exercise in the heat. METHODS After dehydration (-4% of body weight), eight nonacclimated highly trained cyclists (age = 24 +/- 1 yr; VO2 = 61.4 +/- 0.8 mL.kg.min-1) performed three experimental trials. Rehydration (randomized, cross-over design) included: 1) ORAL (0.45% NaCl) equal to 50% of prior dehydration; 2) IV (0.45% NaCl) equal to 50% of prior dehydration; and 3) a control (CON), no fluid trial. Subjects then cycled at 74% VO2peak until volitional exhaustion in a hot environment (37 degrees C). RESULTS Central (C-), local (L-), and overall-RPE (O-RPE) were significantly higher in CON compared to ORAL and IV at minutes 5 and 15 of exercise. C-RPE responses at minute 5 of exercise were lower (P < 0.05) during ORAL compared with IV, and C-RPE and O-RPE responses at minute 15 were lower (P < 0.05) during ORAL compared with IV. TS responses during CON were higher (P < 0.05) than ORAL and IV at minute 5, and TS was higher (P < 0.05) during IV versus ORAL at minute 15. TS were significantly correlated with all RPE responses at minute 15 in all trials. Thirst ratings were lower (P < 0.05) during ORAL compared with CON and IV at minutes 0, 5, and 15. CONCLUSION It was concluded that ORAL resulted in lower RPE, thirst, and TS compared with CON and IV during exercise in the heat.
Collapse
Affiliation(s)
- C M Maresh
- Human Performance Laboratory, Department of Kinesiology, University of Connecticut, 2095 Hillside Road, Storrs, CT 06269-1110, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Kenefick RW, Maresh CM, Armstrong LE, Castellani JW, Riebe D, Echegaray ME, Kavorous SA. Plasma vasopressin and aldosterone responses to oral and intravenous saline rehydration. J Appl Physiol (1985) 2000; 89:2117-22. [PMID: 11090557 DOI: 10.1152/jappl.2000.89.6.2117] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This investigation examined plasma arginine vasopressin (AVP) and aldosterone (Ald) responses to 1) oral and intravenous (IV) methods of rehydration (Rh) and 2) different IV Rh osmotic loads. We hypothesized that AVP and Ald responses would be similar between IV and oral Rh and that the greater osmolality and sodium concentration of a 0.9% IV saline treatment would stimulate a greater AVP response compared with a 0.45% IV saline treatment. On four occasions, eight men (age: 22.1 +/- 0.8 yr; height: 179.6 +/- 1.5 cm; weight: 73.6 +/- 2.5 kg; maximum O(2) consumption: 57.9 +/- 1.6 ml. kg(-1). min(-1), body fat: 7.7 +/- 0.9%) performed a dehydration (Dh) protocol (33 degrees C) to establish a 4-5% reduction in body weight. After Dh, subjects underwent each of three randomly assigned Rh (back to -2% body wt) treatments (0.9 and 0.45% IV saline, 0.45% oral saline) and a no Rh treatment during the first 45 min of a 100-min rest period. Blood samples were obtained pre-Dh, immediately post-Dh, and at 15, 35, and 55 min post-Rh. Before Dh, plasma AVP and Ald were not different among treatments but were significantly elevated post-Dh. In general, at 15, 35, and 55 min post-Rh, AVP, Ald, osmolality, and plasma volume shifts did not differ between IV and oral fluid replacement. These results demonstrated that the manner in which plasma AVP and Ald responded to oral and IV Rh or to different sodium concentrations (0.9 vs. 0.45%) was not different given the degree of Dh (-4.5% body wt) and Rh and amount of time after Rh (55 min).
Collapse
Affiliation(s)
- R W Kenefick
- Department of Kinesiology, The University of New Hampshire, Durham, New Hampshire 03824, USA.
| | | | | | | | | | | | | |
Collapse
|
26
|
Abstract
Exercise performance can be compromised by a body water deficit, particularly when exercise is performed in hot climates. It is recommended that individuals begin exercise when adequately hydrated. This can be facilitated by drinking 400 mL to 600 mL of fluid 2 hours before beginning exercise and drinking sufficient fluid during exercise to prevent dehydration from exceeding 2% body weight. A practical recommendation is to drink small amounts of fluid (150-300 mL) every 15 to 20 minutes of exercise, varying the volume depending on sweating rate. Core temperature, heart rate, and perceived effort remain lowest when fluid replacement comes closest to matching the rate of sweat loss. During exercise lasting less than 90 minutes, water alone is sufficient for fluid replacement. During prolonged exercise lasting longer than 90 minutes, commercially available carbohydrate electrolyte beverages should be considered to provide an exogenous carbohydrate source to sustain carbohydrate oxidation and endurance performance. Electrolyte supplementation is generally not necessary because dietary intake is adequate to offset electrolytes lost in sweat and urine; however, during initial days of hot-weather training or when meals are not calorically adequate, supplemental salt intake may be indicated to sustain sodium balance.
Collapse
Affiliation(s)
- W A Latzka
- Thermal and Mountain Medicine Division, US Army Research Institute of Environmental Medicine, Natick, Massachusetts, USA.
| | | |
Collapse
|
27
|
Marlin DJ, Scott CM, Mills PC, Louwes H, Vaarten J. Rehydration following exercise: effects of administration of water versus an isotonic oral rehydration solution (ORS). Vet J 1998; 156:41-9. [PMID: 9691850 DOI: 10.1016/s1090-0233(98)80060-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The effects of administering (1) 6L isotonic oral rehydration solution (ORS), similar in composition to plasma (except for an elevated potassium concentration) and with an osmotic skeleton and (2) 6L water (no osmotic skeleton), were evaluated in five thoroughbred horses following exercise-induced dehydration. The horses were exercised on a treadmill for 10 min at walk (1.7 m.s-1; approximately 15% VO2max), 40 min at trot (3.7 m.s-1; approximately 25% VO2max) and 10 min at walk (1.7 m.s-1; approximately 15% VO2max). Exercise was undertaken on a 3 degrees incline at 30 degrees C/80% RH. Solutions of water or ORS at 20 degrees C were administered by nasogastric tube over 60s 5 min following exercise. Mean weight loss following exercise was 9.2 +/- 1.7 kg (2.0 +/- 0.4% body weight; mean +/- SEM) with water and 9.2 +/- 1.1 kg (2.0 +/- 0.2% body weight) with ORS and was not different between treatments (P > 0.05). Water treatment resulted in a fall in plasma [Na+] (approximately 3 mmol.L-1) and C1- (1-2 mmol.L-1) concentrations by 30 min after administration and the effect persisted until the end of the study (300 min post fluids). There was little change in plasma total protein (TP) from that at the end of exercise, suggesting a failure of water to restore or maintain PV. In contrast, ORS administration resulted in a small increase in plasma [Na+] (1-2 mmol.L-1) and [Cl-] (2-3 mmol.L-1) with a corresponding decrease in plasma TP. By 120 min post ORS, plasma TP and PV were no longer significantly different from rest or pre-exercise (P > 0.05), whilst with water, TP was elevated (approximately 3-4 g.L-1) and PV reduced (approximately 4-5 mL.kg-1). Total urine output was not significantly different between water (1096 +/- 135 mL) and ORS (750 +/- 215 mL, P > 0.05). Estimates of expected plasma volume and electrolyte concentration changes as a result of either treatment compared well with measured changes of TP and PV. On the basis of calculated or measured changes, it was estimated that only 1L of water contributed to rehydration following exercise compared to 4L isotonic, plasma-like ORS. The administration of 6L ORS restored the PV deficit induced by exercise with minimal or no disturbance of plasma electrolyte concentrations. In contrast, water alone resulted in minimal improvement in PV. When fluid intake after periods of fluid loss, such as induced by exercise or transport, is not accompanied by food intake, the present study has clearly demonstrated that water alone is ineffective in promoting rehydration compared with an isotonic, plasma-like ORS.
Collapse
Affiliation(s)
- D J Marlin
- Centre for Equine Studies, Animal Health Trust, Kentford, Newmarket, Suffolk, UK
| | | | | | | | | |
Collapse
|