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Le Page AK, Johnson EC, Greenberg JH. Is mild dehydration a risk for progression of childhood chronic kidney disease? Pediatr Nephrol 2024:10.1007/s00467-024-06332-6. [PMID: 38632124 DOI: 10.1007/s00467-024-06332-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 02/21/2024] [Accepted: 02/22/2024] [Indexed: 04/19/2024]
Abstract
Children with chronic kidney disease (CKD) can have an inherent vulnerability to dehydration. Younger children are unable to freely access water, and CKD aetiology and stage can associate with reduced kidney concentrating capacity, which can also impact risk. This article aims to review the risk factors and consequences of mild dehydration and underhydration in CKD, with a particular focus on evidence for risk of CKD progression. We discuss that assessment of dehydration in the CKD population is more challenging than in the healthy population, thus complicating the definition of adequate hydration and clinical research in this field. We review pathophysiologic studies that suggest mild dehydration and underhydration may cause hyperfiltration injury and impact renal function, with arginine vasopressin as a key mediator. Randomised controlled trials in adults have not shown an impact of improved hydration in CKD outcomes, but more vulnerable populations with baseline low fluid intake or poor kidney concentrating capacity need to be studied. There is little published data on the frequency of dehydration, and risk of complications, acute or chronic, in children with CKD. Despite conflicting evidence and the need for more research, we propose that paediatric CKD management should routinely include an assessment of individual dehydration risk along with a treatment plan, and we provide a framework that could be used in outpatient settings.
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Affiliation(s)
- Amelia K Le Page
- Department of Nephrology, Monash Children's Hospital, Clayton, VIC, Australia.
- Department of Pediatrics, School of Clinical Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, VIC, Australia.
| | - Evan C Johnson
- Division of Kinesiology & Health, College of Health Sciences, University of Wyoming, Laramie, WY, USA
| | - Jason H Greenberg
- Section of Nephrology, Department of Pediatrics, Yale University School of Medicine, New Haven, CT, USA
- Department of Internal Medicine, Clinical and Translational Research Accelerator, Yale University, New Haven, CT, USA
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2
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Takamata A, Oka A, Nagata M, Kosugi N, Eguchi S, Sakagawa N, Takahashi A, Nishimoto Y, Nishimaki M, Morimoto K, Takihara T. Effect of fluid replacement with green tea on body fluid balance and renal responses under mild thermal hypohydration: a randomized crossover study. Eur J Nutr 2023; 62:3339-3347. [PMID: 37594507 DOI: 10.1007/s00394-023-03236-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 08/08/2023] [Indexed: 08/19/2023]
Abstract
PURPOSE Maintaining an appropriate hydration level by ingesting fluid in a hot environment is a measure to prevent heat-related illness. Caffeine-containing beverages, including green tea (GT), have been avoided as inappropriate rehydration beverages to prevent heat-related illness because caffeine has been assumed to exert diuretic/natriuretic action. However, the influence of caffeine intake on urine output in dehydrated individuals is not well documented. The aim of the present study was to examine the effect of fluid replacement with GT on body fluid balance and renal water and electrolyte handling in mildly dehydrated individuals. METHODS Subjects were dehydrated by performing three bouts of stepping exercise for 20 min separated by 10 min of rest. They were asked to ingest an amount of water (H2O), GT, or caffeinated H2O (20 mg/100 ml; Caf-H2O) that was equal to the volume of fluid loss during the dehydration protocol; fluid balance was measured for 2 h after fluid ingestion. RESULTS The dehydration protocol induced hypohydration by ~ 10 g/kg body weight (~ 1% of body weight). Fluid balance 2 h after fluid ingestion was significantly less negative in all trials, and the fluid retention ratio was 52.2 ± 4.2% with H2O, 51.0 ± 5.0% with GT, and 47.9 ± 6.2% with Caf-H2O; those values did not differ among the trials. After rehydration, urine output, urine osmolality, and urinary excretions of osmotically active substances, sodium, potassium and chloride were not different among the trials. CONCLUSION The data indicate that ingestion of GT or an equivalent caffeine amount does not worsen the hydration level 2 h after ingestion and can be effective in reducing the negative fluid balance for acute recovery from mild hypohydration. TRIAL REGISTRATION ISRCTN53057185; retrospectively registered.
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Affiliation(s)
- Akira Takamata
- Department of Environmental Health, Nara Women's University, Nara, Japan.
| | - Ayano Oka
- Department of Environmental Health, Nara Women's University, Nara, Japan
| | - Mayuna Nagata
- Department of Environmental Health, Nara Women's University, Nara, Japan
| | - Natsumi Kosugi
- Department of Environmental Health, Nara Women's University, Nara, Japan
| | - Sayaka Eguchi
- Department of Environmental Health, Nara Women's University, Nara, Japan
| | - Nanako Sakagawa
- Department of Environmental Health, Nara Women's University, Nara, Japan
| | - Aoi Takahashi
- Department of Environmental Health, Nara Women's University, Nara, Japan
| | - Yuki Nishimoto
- Department of Environmental Health, Nara Women's University, Nara, Japan
| | - Mio Nishimaki
- Department of Environmental Health, Nara Women's University, Nara, Japan
| | - Keiko Morimoto
- Department of Environmental Health, Nara Women's University, Nara, Japan
- Department of Health and Nutrition, Kyoto Koka Women's University, Kyoto, Japan
| | - Takanobu Takihara
- Central Research Institute, ITO EN, Ltd., Makinohara, Shizuoka, Japan
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3
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Deshayes TA, Pancrate T, Goulet ED. Impact of dehydration on perceived exertion during endurance exercise: A systematic review with meta-analysis. J Exerc Sci Fit 2022; 20:224-235. [PMID: 35601980 PMCID: PMC9093000 DOI: 10.1016/j.jesf.2022.03.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 03/09/2022] [Accepted: 03/28/2022] [Indexed: 11/20/2022] Open
Abstract
Background Understanding the impact of stressors on the rating of perceived exertion (RPE) is relevant from a performance and exercise adherence/participation standpoint. Athletes and recreationally active individuals dehydrate during exercise. No attempt has been made to systematically determine the impact of exercise-induced dehydration (EID) on RPE. Objective The present meta-analysis aimed to determine the effect of EID on RPE during endurance exercise and examine the moderating effect of potential confounders. Data analyses Performed on raw RPE values using random-effects models weighted mean effect summaries and meta-regressions with robust standard errors, and with a practical meaningful effect set at 1 point difference between euhydration (EUH) and EID. Only controlled crossover studies measuring RPE with a Borg scale in healthy adults performing ≥30 min of continuous endurance exercise while dehydrating or drinking to maintain EUH were included. Results Sixteen studies were included, representing 147 individuals. Mean body mass loss with EUH was 0.5 ± 0.4%, compared to 2.3 ± 0.5% with EID (range 1.7-3.1%). Within an EID of 0.5-3% body mass, a maximum difference in RPE of 0.81 points (95% CI: 0.36-1.27) was observed between conditions. A meta-regression revealed that RPE increases by 0.21 points for each 1% increase in EID (95% CI: 0.12-0.31). Humidity, ambient temperature and aerobic capacity did not alter the relationship between EID and RPE. Conclusion Therefore, the effect of EID on RPE is unlikely to be practically meaningful until a body mass loss of at least 3%.
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Affiliation(s)
- Thomas A. Deshayes
- Faculty of Physical Activity Sciences, University of Sherbrooke, P.Q., Canada
- Research Center on Aging, University of Sherbrooke, P.Q., Canada
| | - Timothée Pancrate
- Faculty of Physical Activity Sciences, University of Sherbrooke, P.Q., Canada
| | - Eric D.B. Goulet
- Faculty of Physical Activity Sciences, University of Sherbrooke, P.Q., Canada
- Research Center on Aging, University of Sherbrooke, P.Q., Canada
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Sansone JE, Guyer MS, Mullin EM, Thompson B. Fluid Restriction Dehydration Increase Core Temperature During Endurance Exercise Compared to Exercise Induced Dehydration. Int J Exerc Sci 2022; 15:166-176. [PMID: 36895794 PMCID: PMC9987426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 03/11/2023]
Abstract
This study aimed to evaluate the difference in heart rate and core temperature during aerobic exercise between two forms of dehydration: exercise-induced (EI) and fluid restricted (FR). Twenty-two subjects (N = 22; 83.35 ± 13.92 kg) completed the current study, performing a familiarization session, a pre-experimental exercise session, and two exercise testing sessions. The EI exercise trial (81.52 ± 13.72 kg) was conducted after performing exercise in a hot environment to lose three to four percent of body weight and partial rehydration. The FR exercise trial (81.53 ± 14.14 kg) was completed after 12 hours of fluid restriction. During both exercise sessions, subjects pedaled against a set resistance of 130 watts for 30 minutes. The main effect of hydration on Tc was significant, F(1, 18) = 4.474, p = .049, η p 2 = .199 (Figure 2) with core temperature being greater during the FR trial compared to the EI trial (FR = 37.58 ± .06°C vs. EI = 37.31 ± .11°C). No significant interaction was found between hydration and time for HR, F(2, 42) = 0.120, p = .887, η p 2 = .006. The main effect of time on HR was significant, F(2, 42) = 119.664, p < .001, η p 2 = .851. Fluid restriction was associated with an increase in core temperature. An increased core temperature may negatively influence performance, and care should be taken to ensure proper hydration.
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Affiliation(s)
- Jessica E Sansone
- Springfield College, Springfield MA, USA.,Shenandoah University, Winchester VA, USA
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5
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Abstract
PURPOSE OF REVIEW We define dehydration and its relationship to pain physiology including both primary and secondary headache disorders. RECENT FINDINGS Intravenous fluids administered for acute migraine attacks in an emergency department setting have not been shown to improve pain outcomes. However, increased intravascular volume before diagnostic lumbar puncture may reduce the frequency of post-lumbar puncture headache from iatrogenic spinal fluid leak. Maintenance of euhydration can help treat orthostatic and "coat-hanger" headache due to autonomic disorders. Similarly, prevention of fluid losses can mitigate secondary headaches provoked by dehydration such as cerebral venous thrombosis or pituitary apoplexy. Dehydration alone may cause headache, but oftentimes exacerbates underlying medical conditions such as primary headache disorders or other conditions dependent on fluid balance.
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Affiliation(s)
- Karissa N Arca
- Mayo Clinic Arizona, 13400 E Shea Blvd, Scottsdale, AZ, 85259, USA.
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Caldwell AR, Rosa-Caldwell ME, Keeter C, Johnson EC, Péronnet F, Ganio MS. Effects of a 14-Day Hydration Intervention on Individuals with Habitually Low Fluid Intake. Ann Nutr Metab 2021; 76 Suppl 1:67-68. [PMID: 33780930 DOI: 10.1159/000515375] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 11/17/2020] [Indexed: 11/19/2022]
Abstract
BACKGROUND Debate continues over whether or not individuals with low total water intake (TWI) are in a chronic fluid deficit (i.e., low total body water) [<xref ref-type="bibr" rid="ref1">1</xref>]. When women with habitually low TWI (1.6 ± 0.5 L/day) increased their fluid intake (3.5 ± 0.1 L/day) for 4 days 24-h urine osmolality decreased, but there was no change in body weight, a proxy for total body water (TBW) [<xref ref-type="bibr" rid="ref2">2</xref>]. In a small (n = 5) study of adult men, there were no observable changes in TBW, as measured by bioelectrical impedance, after increasing TWI for 4 weeks [<xref ref-type="bibr" rid="ref3">3</xref>]. However, body weight increased and salivary osmolality decreased indicating that the study may have been underpowered to detect changes in TBW. Further, no studies to date have measured changes in blood volume (BV) when TWI is increased. OBJECTIVES Therefore, the purpose of this study was to identify individuals with habitually low fluid intake and determine if increasing TWI, for 14 days, resulted in changes in TBW or BV. METHODS In order to identify individuals with low TWI, 889 healthy adults were screened. Participants with a self-reported TWI less than 1.8 L/day (men) or 1.2 L/day (women), and a 24-h urine osmolality greater than 800 mOsm were included in the intervention phase of the study. For the intervention phase, 15 participants were assigned to the experimental group and 8 participants were assigned to the control group. The intervention period lasted for 14 days and consisted of 2 visits to our laboratory: one before the intervention (baseline) and 14 days into the intervention (14-day follow-up). At these visits, BV was measured using a CO-rebreathe procedure and deuterium oxide (D2O) was administered to measure TBW. Urine samples were collected immediately prior, and 3-8 h after the D2O dose to allow for equilibration. Prior to each visit, participants collected 24-h urine to measure 24-h hydration status. After the baseline visit, the experimental group increased their TWI to 3.7 L for males and 2.7 L for females in order to meet the current Institute of Medicine recommendations for TWI. RESULTS Twenty-four-hour urine osmolality decreased (-438.7 ± 362.1 mOsm; p < 0.001) and urine volume increased (1,526 ± 869 mL; p < 0.001) in the experimental group from baseline, while there were no differences in osmolality (-74.7 ± 572 mOsm; p = 0.45), or urine volume (-32 ± 1,376 mL; p = 0.89) in the control group. However, there were no changes in BV (Fig. <xref ref-type="fig" rid="f01">1</xref>a) or changes in TBW (Fig. <xref ref-type="fig" rid="f01">1</xref>b) in either group. CONCLUSIONS Increasing fluid intake in individuals with habitually low TWI increases 24-h urine volume and decreases urine osmolality but does not result in changes in TBW or BV. These findings are in agreement with previous work indicating that TWI interventions lasting 3 days [<xref ref-type="bibr" rid="ref2">2</xref>] to 4 weeks [<xref ref-type="bibr" rid="ref3">3</xref>] do not result in changes in TBW. Current evidence would suggest that the benefits of increasing TWI are not related changes in TBW.
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Affiliation(s)
- Aaron R Caldwell
- Exercise Science Research Center, University of Arkansas-Fayetteville, Fayetteville, Arkansas, USA
| | - Megan E Rosa-Caldwell
- Exercise Science Research Center, University of Arkansas-Fayetteville, Fayetteville, Arkansas, USA
| | - Carson Keeter
- Hydration Physiology Laboratory, University of Wyoming, Laramie, Wyoming, USA
| | - Evan C Johnson
- Hydration Physiology Laboratory, University of Wyoming, Laramie, Wyoming, USA
| | | | - Matthew S Ganio
- Exercise Science Research Center, University of Arkansas-Fayetteville, Fayetteville, Arkansas, USA
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7
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Abstract
Background Despite a substantial body of research, no clear best practice guidelines exist for the assessment of hydration in athletes. Body water is stored in and shifted between different sites throughout the body complicating hydration assessment. This review seeks to highlight the unique strengths and limitations of various hydration assessment methods described in the literature as well as providing best practice guidelines. Main body There is a plethora of methods that range in validity and reliability, including complicated and invasive methods (i.e. neutron activation analysis and stable isotope dilution), to moderately invasive blood, urine and salivary variables, progressing to non-invasive metrics such as tear osmolality, body mass, bioimpedance analysis, and sensation of thirst. Any single assessment of hydration status is problematic. Instead, the recommended approach is to use a combination, which have complementary strengths, which increase accuracy and validity. If methods such as salivary variables, urine colour, vital signs and sensation of thirst are utilised in isolation, great care must be taken due to their lack of sensitivity, reliability and/or accuracy. Detailed assessments such as neutron activation and stable isotope dilution analysis are highly accurate but expensive, with significant time delays due to data analysis providing little potential for immediate action. While alternative variables such as hormonal and electrolyte concentration, bioimpedance and tear osmolality require further research to determine their validity and reliability before inclusion into any test battery. Conclusion To improve best practice additional comprehensive research is required to further the scientific understanding of evaluating hydration status.
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Affiliation(s)
- Oliver R Barley
- Centre for Exercise and Sports Science Research, School of Medical and Health Sciences, Edith Cowan University, 270 Joondalup Drive, Joondalup, WA, 6027, Australia.
| | - Dale W Chapman
- Centre for Exercise and Sports Science Research, School of Medical and Health Sciences, Edith Cowan University, 270 Joondalup Drive, Joondalup, WA, 6027, Australia.,Performance Support, New South Wales Institute of Sport, Sydney Olympic Park, NSW, Australia
| | - Chris R Abbiss
- Centre for Exercise and Sports Science Research, School of Medical and Health Sciences, Edith Cowan University, 270 Joondalup Drive, Joondalup, WA, 6027, Australia
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8
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El-Sharkawy AM, Devonald MAJ, Humes DJ, Sahota O, Lobo DN. Hyperosmolar dehydration: A predictor of kidney injury and outcome in hospitalised older adults. Clin Nutr 2020; 39:2593-2599. [PMID: 31801657 PMCID: PMC7403861 DOI: 10.1016/j.clnu.2019.11.030] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 11/13/2019] [Accepted: 11/14/2019] [Indexed: 12/29/2022]
Abstract
BACKGROUND & AIMS Hospitalised older adults are vulnerable to dehydration. However, the prevalence of hyperosmolar dehydration (HD) and its impact on outcome is unknown. Serum osmolality is not measured routinely but osmolarity, a validated alternative, can be calculated using routinely measured serum biochemistry. This study aimed to use calculated osmolarity to measure the prevalence of HD (serum osmolarity >300 mOsm/l) and assess its impact on acute kidney injury (AKI) and outcome in hospitalised older adults. METHODS This retrospective cohort study used data from a UK teaching hospital retrieved from the electronic database relating to all medical emergency admissions of patients aged ≥ 65 years admitted between 1st May 2011 and 31st October 2013. Using these data, Charlson comorbidity index (CCI), National Early Warning Score (NEWS), length of hospital stay (LOS) and mortality were determined. Osmolarity was calculated using the equation of Krahn and Khajuria. RESULTS A total of 6632 patients were identified; 27% had HD, 39% of whom had AKI. HD was associated with a median (Q1, Q3) LOS of 5 (1, 12) days compared with 3 (1, 9) days in the euhydrated group, P < 0.001. Adjusted Cox-regression analysis demonstrated that patients with HD were four-times more likely to develop AKI 12-24 h after admission [Hazards Ratio (95% Confidence Interval) 4.5 (3.5-5.6), P < 0.001], and had 60% greater 30-day mortality [1.6 (1.4-1.9), P < 0.001], compared with those who were euhydrated. CONCLUSION HD is common in hospitalised older adults and is associated with increased LOS, risk of AKI and mortality. Further work is required to assess the validity of osmolality or osmolarity as an early predictor of AKI and the impact of HD on outcome prospectively.
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Affiliation(s)
- Ahmed M El-Sharkawy
- Gastrointestinal Surgery, Nottingham Digestive Diseases Centre, National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and University of Nottingham, Queen's Medical Centre, Nottingham, NG7 2UH, UK
| | - Mark A J Devonald
- Renal and Transplant Unit, Nottingham University Hospitals NHS Trust, City Campus, Nottingham, NG5 1PB, UK
| | - David J Humes
- Gastrointestinal Surgery, Nottingham Digestive Diseases Centre, National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and University of Nottingham, Queen's Medical Centre, Nottingham, NG7 2UH, UK; Division of Epidemiology and Public Health, University of Nottingham, City Campus, Nottingham NG5 1PB, UK
| | - Opinder Sahota
- Department of Elderly Medicine, Nottingham University Hospitals NHS Trust, Queen's Medical Centre, Nottingham, NG7 2UH, UK
| | - Dileep N Lobo
- Gastrointestinal Surgery, Nottingham Digestive Diseases Centre, National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and University of Nottingham, Queen's Medical Centre, Nottingham, NG7 2UH, UK; MRC Versus Arthritis Centre for Musculoskeletal Ageing Research, School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham, NG7 2UH, UK.
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TOKIZAWA K, SON SY, OKA T, YASUDA A. Effectiveness of a field-type liquid cooling vest for reducing heat strain while wearing protective clothing. Ind Health 2020; 58:63-71. [PMID: 31406053 PMCID: PMC6997718 DOI: 10.2486/indhealth.2018-0182] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 06/25/2019] [Indexed: 05/27/2023]
Abstract
This study examined the effectiveness of a field-type liquid cooling vest (LCV) worn underneath an impermeable protective suit on heat strain during walking. Eight men walked for 60 min at a moderate speed (3.0 km/h) wearing the suit in a warm environment (33°C, 60% relative humidity) without (control, CON) or with the LCV. A smaller increase in rectal temperature was recorded in participants in the LCV than in the CON condition (37.6 ± 0.1°C vs. 37.9 ± 0.1°C, p<0.05). Walking while wearing the LCV reduced the level of physiological heat strain, as measured by the mean skin temperature (35.5 ± 0.1°C vs. 36.3 ± 0.1°C), chest sweat rate (13.5 ± 3.0 mg/cm2/h vs. 16.6 ± 3.8 mg/cm2/h), chest cutaneous vascular conductance (349 ± 88% vs. 463 ± 122%), body weight loss (0.72 ± 0.05% vs. 0.93 ± 0.06%), and heart rate (101 ± 6 beats/min vs. 111 ± 7 beats/min) (p<0.05, for all comparisons). These changes were accompanied by a decrease in thermal sensation and discomfort. These results suggest that a field-type LCV attenuates exertional heat strain while wearing impermeable protective clothing.
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Affiliation(s)
- Ken TOKIZAWA
- National Institute of Occupational Safety and Health,
Japan
| | - Su-Young SON
- National Institute of Occupational Safety and Health,
Japan
- Present address: Kyungpook National University, Korea
| | - Tatsuo OKA
- National Institute of Occupational Safety and Health,
Japan
| | - Akinori YASUDA
- National Institute of Occupational Safety and Health,
Japan
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10
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Johnson EC, Huffman AE, Yoder H, Dolci A, Perrier ET, Larson-Meyer DE, Armstrong LE. Urinary markers of hydration during 3-day water restriction and graded rehydration. Eur J Nutr 2019; 59:2171-2181. [PMID: 31428854 PMCID: PMC7351875 DOI: 10.1007/s00394-019-02065-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 07/17/2019] [Indexed: 11/29/2022]
Abstract
PURPOSE This investigation had three purposes: (a) to evaluate changes in hydration biomarkers in response to a graded rehydration intervention (GRHI) following 3 days of water restriction (WR), (b) assess within-day variation in urine concentrations, and (c) quantify the volume of fluid needed to return to euhydration as demonstrated by change in Ucol. METHODS 115 adult males and females were observed during 1 week of habitual fluid intake, 3 days of fluid restriction (1000 mL day-1), and a fourth day in which the sample was randomized into five different GRHI groups: no additional water, CON; additional 500 mL, G+0.50; additional 1000 mL, G+1.00; additional 1500 mL, G+1.50; additional 2250 mL, G+2.25. All urine was collected on 1 day of the baseline week, during the final 2 days of the WR, and during the day of GRHI, and evaluated for urine osmolality, color, and specific gravity. RESULTS Following the GRHI, only G+1.50 and G+2.25 resulted in all urinary values being significantly different from CON. The mean volume of water increase was significantly greater for those whose Ucol changed from > 4 to < 4 (+ 1435 ± 812 mL) than those whose Ucol remained ≥ 4 (+ 667 ± 722 mL, p < 0.001). CONCLUSIONS An additional 500 mL of water is not sufficient, while approximately 1500 mL of additional water (for a total intake between 2990 and 3515 mL day-1) is required to return to a urine color associated with adequate water intake, following 3 days of WR.
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Affiliation(s)
- Evan C Johnson
- Human Integrated Physiology Laboratory, University of Wyoming, 1000 E. University Ave, Laramie, WY, 82071, USA.
| | - Ainsley E Huffman
- Human Integrated Physiology Laboratory, University of Wyoming, 1000 E. University Ave, Laramie, WY, 82071, USA.,University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Hillary Yoder
- Human Integrated Physiology Laboratory, University of Wyoming, 1000 E. University Ave, Laramie, WY, 82071, USA.,Department of Kinesiology, University of Alabama, Tuscaloosa, AL, USA
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11
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Mollica JA, Desbrow B, Irwin CG. No Impact of Heat Stress and Dehydration on Short Duration Simulated Motor-Racing Performance. Int J Exerc Sci 2019; 12:960-970. [PMID: 31523354 PMCID: PMC6719815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Motor-racing drivers are often exposed to hot environments and may be susceptible to fluid loss and hydration issues, which could influence driving performance. This study assessed the effect of dehydration and heat stress on performance during a short, simulated motor-racing task. Nine healthy males (age: 26.6 ± 7.5 y, body mass: 78.8 ± 12.5 kg, mean ± SD) completed two passive dehydration (sauna) procedures (targeting -1% and -3% body mass loss (BML)) on separate occasions. Driving performance was assessed pre-dehydration (Baseline), immediately post-dehydration (Hot) and following a cooling period (Cool). Measures of driving performance included lap time and sector-time for one section of the track. Subjective ratings of mood, thermal stress and comfort were also collected during trials. Mean lap times were not different between Baseline, Hot, Cool conditions for both 1% (68.44 ± 1.43 s, 68.06 ± 1.17 s, 68.23 ± 1.25 s) and 3% (68.33 ± 1.68 s, 68.01 ± 1.15 s, 68.06 ± 1.26 s) trials respectively. In addition, mean sector times were not different between Baseline, Hot, Cool conditions for both 1% (11.61 ± 0.28 s, 11.55 ± 0.45 s, 11.59 ± 0.35 s) and 3% (11.49 ± 0.33 s, 11.56 ± 0.33 s, 11.63 ± 0.71 s) trials respectively. Changes in participants' subjective ratings (i.e. decreased alertness, concentration and comfort; increased tiredness and light-headedness) were observed at both levels of dehydration (1% and 3% BML), irrespective of heat stress. Thus, fluid loss and heat stress are unlikely to affect driver's motor-racing performance during short duration events. However, the impact of dehydration and heat stress on tasks of longer duration that accurately represent the demands associated with motor-racing requires further consideration.
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Affiliation(s)
- Jamie A Mollica
- School of Allied Health Sciences, Griffith University, Gold Coast, Queensland, AUSTRALIA
| | - Ben Desbrow
- School of Allied Health Sciences, Griffith University, Gold Coast, Queensland, AUSTRALIA
| | - Christopher G Irwin
- School of Allied Health Sciences, Griffith University, Gold Coast, Queensland, AUSTRALIA
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12
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Al-Tamimi H, Al-Atiyat R, Al-Majali A, Alameri O. Renal efficiency underlies adaptive heterothermy of heat-stressed hypohydrated goats. Trop Anim Health Prod 2019; 51:2287-95. [PMID: 31154615 DOI: 10.1007/s11250-019-01948-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 05/24/2019] [Indexed: 12/15/2022]
Abstract
We investigated the thermotolerance of the F1 progeny (Black Bedouin × Damascus crossbreed) to summer conditions alongside that of two pure breeds. Male goats (n = 7 per breed) were used to conduct a summertime 28-day trial along with hypohydration. The animals were fitted with miniscule thermologgers, intraperitoneally and subcutaneously, to measure core (Tc) and peripheral (Tp) body temperatures (BT), respectively. All goats were kept under shaded housing for a 7-day basal period before being switched to unshaded pens for the next 21 days. During the first 14 days, animals had free access to water. However, during the third 7-day period, access to water was time-restricted (4 h/day). Finally, it was restricted to 40% of the third week's average daily intake over the last 7 days. Exposure to the unshaded conditions resulted in pronounced heat stress in all animals, as reflected by 0.42 and 1.44 °C rises for Tc and Tp, respectively. The F1 goats displayed a clear heterothermic adaptive response, especially after the water restriction bouts' initiation. Interestingly, the F1 goats displayed higher ratios of renal relative medullary thickness (77.7, 73.3, and 72.6 ± 1.1%) along with higher circulating concentrations of antidiuretic hormone (44.6, 31.6, and 11.6 ± 3.7 ng/mL), respectively, which suggested an improved water metabolism.
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Kamaruddin HK, Ooi CH, Mündel T, Aziz AR, Che Muhamed AM. The ergogenic potency of carbohydrate mouth rinse on endurance running performance of dehydrated athletes. Eur J Appl Physiol 2019; 119:1711-23. [PMID: 31098832 DOI: 10.1007/s00421-019-04161-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 05/09/2019] [Indexed: 10/26/2022]
Abstract
PURPOSE To examine the effect of carbohydrate (CHO) mouth rinsing on endurance running responses and performance in dehydrated individuals. METHODS In a double blind, randomised crossover design, 12 well-trained male runners completed 4 running time to exhaustion (TTE) trials at a speed equivalent to 70% of VO2peak in a thermoneutral condition. Throughout each run, participants mouth rinsed and expectorated every 15 min either 25 mL of 6% CHO or a placebo (PLA) solution for 10 s. The four TTEs consisted of two trials in the euhydrated (EU-CHO and EU-PLA) and two trials in the dehydrated (DY-CHO and DY-PLA) state. Prior to each TTE run, participants were dehydrated via exercise and allowed a passive rest period during which they were fed and either rehydrated equivalent to their body mass deficit (i.e., EU trials) or ingested only 50 mL of water (DY trials). RESULTS CHO mouth rinsing significantly improved TTE performance in the DY compared to the EU trials (78.2 ± 4.3 vs. 76.9 ± 3.8 min, P = 0.02). The arousal level of the runners was significantly higher in the DY compared to the EU trials (P = 0.02). There was no significant difference among trials in heart rate, plasma glucose and lactate, and psychological measures. CONCLUSIONS CHO mouth rinsing enhanced running performance significantly more when participants were dehydrated vs. euhydrated due to the greater sensitivity of oral receptors related to thirst and central mediated activation. These results show that level of dehydration alters the effect of brain perception with presence of CHO.
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Jafari P, Mojahedi M, Zareiyan A, Mokaberinejad R, Chaichi Raghimi M, Hakimi F, Parsa E. Water Intake from the Points of View of Rhazes and Avicenna. Complement Med Res 2019; 26:126-132. [PMID: 30893678 DOI: 10.1159/000491706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Accepted: 06/21/2018] [Indexed: 11/19/2022]
Abstract
Owing to the effect of acute and chronic hypohydration on health and the lethal effects of hyperhydration, an appropriate amount of water intake is important for each individual. Traditional Iranian medicine (TIM) is a holistic system one of whose important parts deals with lifestyles and how to maintain health, including the amount of water intake for every person and the appropriate principles of drinking water. In this study, Avicenna's Canon of Medicine, Rhazes' Benefits of Food and Its Harmfulness, and conventional medical articles were reviewed to evaluate the amount of water intake for each person and the principles of drinking water. TIM has expressed an individualized difference in the amount of water intake in the form of temperament and the relationship between the appropriate time of drinking water with other daily activities. In this view, drinking water at the inappropriate time causes liver and gastrointestinal diseases; it can create the foundation for conducting new studies in the field of appropriate water intake and lifestyle changes to reduce malnutrition complications.
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Affiliation(s)
- Parisa Jafari
- Department of Traditional Medicine, School of Traditional Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Morteza Mojahedi
- Traditional Medicine and History of Medical Sciences Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran
| | - Armin Zareiyan
- Department of Public Health, School of Nursing, AJA University of Medical Science, Tehran, Iran
| | - Roshanak Mokaberinejad
- Department of Traditional Medicine, School of Traditional Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran,
| | - Mahshid Chaichi Raghimi
- Department of Traditional Medicine, School of Traditional Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Fatemeh Hakimi
- Department of Traditional Medicine, School of Traditional Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Elham Parsa
- Department of Traditional Medicine, School of Traditional Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Abstract
PURPOSE Although low water intake has been associated with adverse health outcomes, available literature indicated that the majority of children do not meet the water intake guidelines and they are underhydrated based on elevated hydration biomarkers. This review examined the water intake habits and hydration status in children from 32 observational studies (n = 36813). METHODS PubMed, Web of Science, and CINAHL were used to identify relevant articles. Total water/fluid intake from 25 countries was compared with water intake recommendations and underhydration (urine osmolality greater than 800 mmol kg-1) was assessed. Risk of bias was assessed using customized categories following the review guideline for observational studies. RESULTS From 32 studies, only 11 studies reported both water intake and hydration status. 12 out of 24 studies reported mean/median water/fluid intake below the guidelines, while 4 out of 13 studies that assessed hydration status indicated underhydration based on urine osmolality (greater than 800 mmol kg-1). Among the 19 countries that reported comparison of water/fluid intake with guidelines, 60 ± 24% of children (range 10-98%) failed to meet them. CONCLUSION These findings suggest that children are not consuming enough water to be adequately hydrated.
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Affiliation(s)
- HyunGyu Suh
- Hydration Science Lab, Arizona State University, Arizona Biomedical Collaborate, Suite 133, 425 N 5th St, Phoenix, AZ, 85004, USA
| | - Stavros A Kavouras
- Hydration Science Lab, Arizona State University, Arizona Biomedical Collaborate, Suite 133, 425 N 5th St, Phoenix, AZ, 85004, USA.
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16
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MacLeod H, Cooper S, Bandelow S, Malcolm R, Sunderland C. Effects of heat stress and dehydration on cognitive function in elite female field hockey players. BMC Sports Sci Med Rehabil 2018; 10:12. [PMID: 29946473 DOI: 10.1186/s13102-018-0101-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 06/07/2018] [Indexed: 11/10/2022]
Abstract
Background It has previously been suggested that heat exposure and hypohydration have negative effects on cognitive performance, which may impact upon sporting performance. The aim of the present study was to examine the independent effects of heat stress and hypohydration on cognitive performance in elite female field hockey players. Methods Eight unacclimatised elite field hockey players (age: 22 ± 3 y; height: 1.68 ± 0.05 m; body mass: 63.1 ± 6.0 kg) completed a cognitive test battery before and after 50 min of field hockey specific exercise on a treadmill in four experimental trials; two in hot conditions (33.3 ± 0.1 °C), and two in moderate (16.0 ± 3.0 °C), both with and without ad libitum water intake. Results On the visual search test, participants were faster overall in the heat (1941 vs. 2104 ms, p = 0.001). Response times were quicker in the heat on the Sternberg paradigm (463 vs. 473 ms, p = 0.024) and accuracy was improved (by 1.9%, p = 0.004). There was no effect of hydration status on any of the markers of cognitive function. Conclusions Overall, the findings suggest that in elite field hockey players exposure to heat enhances response times and/or accuracy on a battery of cognitive function tests. However, hypohydration does not appear to affect cognitive performance in elite field hockey players.
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Emerson DM, Torres-McGehee TM, Emerson CC, LaSalle TL. Individual fluid plans versus ad libitum on hydration status in minor professional ice hockey players. J Int Soc Sports Nutr 2017; 14:25. [PMID: 28775674 PMCID: PMC5539891 DOI: 10.1186/s12970-017-0183-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 07/27/2017] [Indexed: 12/02/2022] Open
Abstract
Background Despite exercising in cool environments, ice hockey players exhibit several dehydration risk factors. Individualized fluid plans (IFPs) are designed to mitigate dehydration by matching an individual’s sweat loss in order to optimize physiological systems and performance. Methods A randomized control trial was used to examine IFP versus ad libitum fluid ingestion on hydration in 11 male minor professional ice hockey players (mean age = 24.4 ± 2.6 years, height = 183.0 ± 4.6 cm, weight = 92.9 ± 7.8 kg). Following baseline measures over 2 practices, participants were randomly assigned to either control (CON) or intervention (INT) for 10 additional practices. CON participants were provided water and/or carbohydrate electrolyte beverage to drink ad libitum. INT participants were instructed to consume water and an electrolyte-enhanced carbohydrate electrolyte beverage to match sweat and sodium losses. Urine specific gravity, urine color, and percent body mass change characterized hydration status. Total fluid consumed during practice was assessed. Results INT consumed significantly more fluid than CON (1180.8 ± 579.0 ml vs. 788.6 ± 399.7 ml, p = 0.002). However, CON participants replaced only 25.4 ± 12.9% of their fluid needs and INT 35.8 ± 17.5%. Mean percent body mass loss was not significantly different between groups and overall indicated minimal dehydration (<1.2% loss). Pre-practice urine specific gravity indicated CON and INT began hypohydrated (mean = 1.024 ± 0.007 and 1.024 ± 0.006, respectively) and experienced dehydration during practice (post = 1.026 ± 0.006 and 1.027 ± 0.005, respectively, p < 0.001). Urine color increased pre- to post-practice for CON (5 ± 2 to 6 ± 1, p < 0.001) and INT (5 ± 1 to 6 ± 1, p < 0.001). Conclusions Participants consistently reported to practice hypohydrated. Ad libitum fluid intake was not significantly different than IFP on hydration status. Based on urine measures, both methods were unsuccessful in preventing dehydration during practice, suggesting practice-only hydration is inadequate to maintain euhydration in this population when beginning hypohydrated.
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Affiliation(s)
- Dawn M Emerson
- University of South Carolina, Department of Physical Education and Athletic Training, 1300 Wheat Street, Blatt PE Center, Room 218, Columbia, SC 29208 USA.,Current address: Department of Health, Sport, and Exercise Sciences, University of Kansas, Robinson, Room 161, Lawrence, Kansas, 66045 USA
| | - Toni M Torres-McGehee
- University of South Carolina, Department of Physical Education and Athletic Training, 1300 Wheat Street, Blatt PE Center, Room 218, Columbia, SC 29208 USA.,Current address: Department of Exercise Science, University of South Carolina, 921 Assembly Street, Public Health Research Center, Columbia, SC 29208 USA
| | - Charles C Emerson
- University of South Carolina, Department of Physical Education and Athletic Training, 1300 Wheat Street, Blatt PE Center, Room 218, Columbia, SC 29208 USA.,Current address: Department of Athletics, University of Missouri-Kansas City, 5100 Rockhill Road, SRC 201, Kansas City, MO 64110 USA
| | - Teri L LaSalle
- University of South Carolina, Department of Physical Education and Athletic Training, 1300 Wheat Street, Blatt PE Center, Room 218, Columbia, SC 29208 USA.,Current address: Hughston Society, Columbus, GA USA
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Adams WM, Hosokawa Y, Belval LN, Huggins RA, Stearns RL, Casa DJ. Deviation from goal pace, body temperature and body mass loss as predictors of road race performance. J Sci Med Sport 2016; 20:302-306. [PMID: 27720128 DOI: 10.1016/j.jsams.2016.07.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Revised: 07/03/2016] [Accepted: 07/28/2016] [Indexed: 10/20/2022]
Abstract
OBJECTIVES The purpose of this study was to examine the relationship between pacing, gastrointestinal temperature (TGI), and percent body mass loss (%BML) on relative race performance during a warm weather 11.3km road race. DESIGN Observational study of a sample of active runners competing in the 2014 Falmouth Road Race. METHODS Participants ingested a TGI pill and donned a GPS enabled watch with heart rate monitoring capabilities prior to the start of the race. Percent off predicted pace (%OFF) was calculated for seven segments of the race. Separate linear regression analyses were used to assess the relationship between pace, TGI, and %BML on relative race performance. One-way ANOVA was used to analyse post race TGI (≥40°C vs <40°C) on pace and %OFF. RESULTS Larger %BML was associated with faster finish times (R2=0.19, p=0.018), faster average pace (R2=0.29, p=0.012), and a greater %OFF (R2=0.15, p=0.033). %OFF during the first mile (1.61km) significantly predicted overall finish time (R2=0.64, p<0.001) while %OFF during the second mile (3.22km) (R2 change=0.18, p<0.001) further added to the model (R2=0.82, p<0.001). Body temperature (pre race TGI and post race TGI) was not predictive of overall finish time (p>0.05). There was a trend in a slower pace (p=0.055) and greater %OFF (p=0.056) in runners finishing the race with a TGI>40°C. CONCLUSIONS Overall, finish time was influenced by greater variations in pace during the first two miles of the race. In addition, runners who minimized fluid losses and had lower TGI were associated with meeting self-predicted goals.
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Affiliation(s)
- William M Adams
- Korey Stringer Institute, Human Performance Laboratory, Department of Kinesiology, University of Connecticut, United States.
| | - Yuri Hosokawa
- Korey Stringer Institute, Human Performance Laboratory, Department of Kinesiology, University of Connecticut, United States
| | - Luke N Belval
- Korey Stringer Institute, Human Performance Laboratory, Department of Kinesiology, University of Connecticut, United States
| | - Robert A Huggins
- Korey Stringer Institute, Human Performance Laboratory, Department of Kinesiology, University of Connecticut, United States
| | - Rebecca L Stearns
- Korey Stringer Institute, Human Performance Laboratory, Department of Kinesiology, University of Connecticut, United States
| | - Douglas J Casa
- Korey Stringer Institute, Human Performance Laboratory, Department of Kinesiology, University of Connecticut, United States
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Kenefick RW, Cheuvront SN. Physiological adjustments to hypohydration: Impact on thermoregulation. Auton Neurosci 2016; 196:47-51. [PMID: 26944095 DOI: 10.1016/j.autneu.2016.02.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Revised: 02/04/2016] [Accepted: 02/07/2016] [Indexed: 11/25/2022]
Abstract
Sufficient body water is required to sustain thermoregulatory function, thus losses in total body water (TBW) can challenge the thermoregulatory system. A TBW deficit ≥2% body mass (hypohydration) is recognized as the threshold when thermoregulatory function becomes measurably altered. Hypohydration may occur from voluntary fluid restriction, insufficient fluid availability, or thermoregulatory sweating. The secretion and evaporation of sweat important avenues of body heat loss, and if the water lost is not replaced, hypohydration will decrease plasma volume and increase plasma osmotic pressure (hyperosmotic hypovolemia). Both osmotic and/or volume stressors delay the onset and/or reduce the sensitivity of sweating and blood flow responses. The magnitude of hypohydration, environmental heat stress, the population and circumstances of interest will determine the degree, significance and outcome of these thermoregulatory alterations and their contribution to physiological stress.
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Affiliation(s)
- Robert W Kenefick
- U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760, United States.
| | - Samuel N Cheuvront
- U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760, United States
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Affiliation(s)
- B M Pluim
- Medical Department, KNLTB, Amersfoort, The Netherlands
| | - S Racinais
- Research Education Centre, ASPETAR-Qatar Orthopaedic and Sports Medicine Hospital, Doha, Qatar
| | - J D Périard
- Research Education Centre, ASPETAR-Qatar Orthopaedic and Sports Medicine Hospital, Doha, Qatar
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21
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Racinais S, Alonso JM, Coutts AJ, Flouris AD, Girard O, González-Alonso J, Hausswirth C, Jay O, Lee JKW, Mitchell N, Nassis GP, Nybo L, Pluim BM, Roelands B, Sawka MN, Wingo J, Périard JD. Consensus recommendations on training and competing in the heat. Br J Sports Med 2015; 49:1164-73. [PMID: 26069301 PMCID: PMC4602249 DOI: 10.1136/bjsports-2015-094915] [Citation(s) in RCA: 98] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/09/2015] [Indexed: 11/05/2022]
Abstract
Exercising in the heat induces thermoregulatory and other physiological strain that can lead to impairments in endurance exercise capacity. The purpose of this consensus statement is to provide up-to-date recommendations to optimise performance during sporting activities undertaken in hot ambient conditions. The most important intervention one can adopt to reduce physiological strain and optimise performance is to heat acclimatise. Heat acclimatisation should comprise repeated exercise-heat exposures over 1–2 weeks. In addition, athletes should initiate competition and training in a euhydrated state and minimise dehydration during exercise. Following the development of commercial cooling systems (eg, cooling-vest), athletes can implement cooling strategies to facilitate heat loss or increase heat storage capacity before training or competing in the heat. Moreover, event organisers should plan for large shaded areas, along with cooling and rehydration facilities, and schedule events in accordance with minimising the health risks of athletes, especially in mass participation events and during the first hot days of the year. Following the recent examples of the 2008 Olympics and the 2014 FIFA World Cup, sport governing bodies should consider allowing additional (or longer) recovery periods between and during events, for hydration and body cooling opportunities, when competitions are held in the heat.
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Affiliation(s)
- S Racinais
- Athlete Health and Performance Research Centre, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Qatar
| | - J M Alonso
- Sports Medicine Department, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Qatar Medical and Anti-doping Commission, International Association of Athletics Federations (IAAF), Montecarlo, Monaco
| | - A J Coutts
- Sport and Exercise Discipline Group, University of Technology Sydney (UTS), Australia
| | - A D Flouris
- FAME Laboratory, Department of Physical Education and Sport Science, University of Thessaly, Trikala, Greece
| | - O Girard
- Department of Physiology, Faculty of Biology and Medicine, ISSUL, Institute of Sport Sciences, University of Lausanne, Lausanne, Switzerland
| | - J González-Alonso
- Department of Life Sciences, Centre for Sports Medicine and Human Performance, College of Health and Life Sciences, Brunel University London, Uxbridge, UK
| | - C Hausswirth
- Research Department, Laboratory of Sport, Expertise and Performance, French National Institute of Sport (INSEP), Paris, France
| | - O Jay
- Discipline of Exercise and Sport Science, Faculty of Health Sciences, University of Sydney, Lidcombe, Australia
| | - J K W Lee
- Defence Medical and Environmental Research Institute, DSO National Laboratories, Singapore, Singapore Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - N Mitchell
- British Cycling and 'Sky Pro Cycling', National Cycling Centre, Manchester, UK
| | - G P Nassis
- National Sports Medicine Programme, Excellence in Football Project, Aspetar, Qatar Orthopaedic and Sports Medicine Hospital, Doha, Qatar
| | - L Nybo
- Department of Nutrition, Exercise and Sport, Section of Human Physiology, University of Copenhagen, Copenhagen, Denmark
| | - B M Pluim
- Medical Department, Royal Netherlands Lawn Tennis Association (KNLTB), Amersfoort, The Netherlands
| | - B Roelands
- Department of Human Physiology, Vrije Universiteit Brussel, Brussels, Belgium
| | - M N Sawka
- School of Applied Physiology, College of Science, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - J Wingo
- Department of Kinesiology, University of Alabama, Tuscaloosa, USA
| | - J D Périard
- Athlete Health and Performance Research Centre, Aspetar Orthopaedic and Sports Medicine Hospital, Doha, Qatar
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Magal M, Cain RJ, Long JC, Thomas KS. Pre-Practice Hydration Status and the Effects of Hydration Regimen on Collegiate Division III Male Athletes. J Sports Sci Med 2015; 14:23-8. [PMID: 25729285 PMCID: PMC4306777] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 09/29/2014] [Indexed: 06/04/2023]
Abstract
Pre-practice euhydration is key in the prevention of heat related injuries. The pre-practice hydration status of male National Collegiate Athletic Association (NCAA)-Division III athletes and the effects of a direct hydration regimen have yet to be investigated therefore; the aim of the study was 1) to analyze the pre-practice hydration status of current NCAA-DIII male athletes and 2) assess the impact of a directed intervention on pre-practice hydration status. The study was divided into baseline, pre and post intervention phases. For baseline, hydration status through urine specific gravity (USG) and anthropometric indices were measured prior to morning practice. Following baseline, pre-intervention commenced and participants were assigned to either control (CON) or experimental (EXP) groups. The CON and EXP group participants were instructed to maintain normal hydration and diet schedules and record fluid intake for seven days leading to post-intervention. The EXP group participants were asked to consume an additional 23.9 fl oz (~ 750 ml) per day for one week (7 days) leading to post-intervention. After 7 days the same measures were taken. At baseline, the majority of the participants were hypohydrated. Following the intervention, the EXP group participants consumed significantly more fluids than the participants in the CON group (3277.91 ± 1360. 23 ml vs 1931.54 ± 881.81 ml; p < 0.05). A-two-way repeated measure ANOVA revealed a non-significant time or treatment effect for USG or body mass but did demonstrate a significant USG interaction. In addition, an independent t-test examining absolute changes in USG demonstrated a significant difference between groups in which the EXP group improved hydration status and the CON group did not (-0.02 ± 0.006 vs 0.001 ± 0.005 ml; p < 0.05). In addition, there was no significant (p >0.05) difference in the regression slopes or intercepts between the CON and EXP groups when expressed as daily fluid intake per kg body (ml·kg(-1)) and change in USG from pre-intervention to post-intervention. Most of the participants were hypohydrated at baseline/pre-intervention and the direct hydration intervention improved post-intervention hydration status but only to a small extent. Key pointsThe majority of NCAA-DIII male athletes whom we assessed prior to practice through the use of USG appeared to be hypohydrated.The hydration intervention of adding 24.9 fl oz (~750ml) per day to an athlete's daily fluid intake led to a significant increase in fluid consumption but resulted in only small improvements in USG.The only small improvement in hydration status following the intervention may be a result of an intervention volume that is too small or an under-reporting of fluid consumption.
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Affiliation(s)
- Meir Magal
- Division of Mathematics and Sciences, North Carolina Wesleyan College , Rocky Mount, NC, USA
| | - Rebekah J Cain
- Division of Mathematics and Sciences, North Carolina Wesleyan College , Rocky Mount, NC, USA
| | - Josh C Long
- Division of Mathematics and Sciences, North Carolina Wesleyan College , Rocky Mount, NC, USA
| | - Kathleen S Thomas
- Division of Mathematics and Sciences, North Carolina Wesleyan College , Rocky Mount, NC, USA
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