ArticleLiterature Review

The Importance of Good Hydration for Day-to-Day Health

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Abstract

The role of hydration in the maintenance of health is increasingly recognized. Studies in healthy adults show that even mild dehydration impairs a number of important aspects of cognitive function such as concentration, alertness, and short-term memory. However, due to the lack of suitable tools for assessment of hydration status, the effects of hydration on other aspects of day-to-day health and well-being remain to be demonstrated.

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... It is cross-culturally known that daily nutrition is essential to the existence of humans (Rampersaud et al., 2005;Ritz and Berrut, 2005). Deprivation of a meal leads to dysfunctional states of the mind and physical self, such as loss of short-term memory and delayed reaction times (Fischer et al., 2002). ...
... In individually large amounts, each of these types of nutrition can be harmful to the body in terms of weight gain and high cholesterol levels (Fischer et al., 2002;Rampersaud et al., 2005). However, a balanced meal including all four of these energy-builders has the ability to increase cognitive functioning before testing (Fischer et al., 2002;Ritz and Berrut, 2005). Funder (2004) discussed the theory of ascending reticular activating system, or ARAS, in the human brain. ...
... Nutrients are beneficial to both body and mind, and they are the energy that flows through our physical selves (Fischer et al., 2002). Blood flow and neural stimulation is circulated through the body to increase both short and long-term memory storage (Patterson, 2001;Ritz and Berrut, 2005). How do physical symptoms influence mental and cognitive thinking? ...
Article
Memory retention is important for students, and little study has been done to confirm that cognitive processes are sustained by nutrition at the college level. The effect of breakfast on short-term memory retention was tested on 20 students at Saint Martin's University. Subjects were tested on two different days, once after consumption of breakfast foods, and once without consumption of breakfast. Using one word list, three face recognition tests, and one object test, the students were tested to determine whether breakfast aided in their cognitive functioning. After utilizing a paired t-test to statistically analyze the data, it was suggested that there was a significant difference between the breakfast consumers and those who did not consume breakfast (t=3.39; p=0.003). Overall precision in short-term memory showed that 16 students improved in memory testing after the consumption of breakfast. Many college students do not have the time for a meal before classes, however this study suggests that breakfast consumption may have positive effects on memory retention within the college classroom.
... Most of the water in the body comes from ingestion, either as beverages or food; only a small fraction comes from cell metabolism. In usual conditions, daily beverage intake varies between 2.5 and 3.0 liters [2]. However, recommendations about daily fluid intake vary widely between countries [3,4]. ...
... These two findings may have important implications for health. As for the first finding, it should be looked at by pointing that there is overall agreement within the scientific community about the need to consume water regularly and in enough amounts to maintain good health [2]; however, there is no general agreement about what should be the recommended amount of water intake. For example, the Institute BioMed Research International 5 of Medicine in the US recommends intake of 3.7 L/day for males and 2.7 L/day for females [4], while the European Food Safety Authority recently recommended intakes of 2.5 L/day for males and 2 L/day for females [3]. ...
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The objective of this study was to describe daily fluid consumption in a sample of pregnant or lactating adult women. Women between 18 and 45 years of age, residents of Mexico City, stratified by socioeconomic status were asked to register their total fluid intake during 7 consecutive days. A total of 153 pregnant and 155 lactating women were recruited. On average, they drank 2.62 L/day and 2.75 L/day, respectively. Forty-one percent of pregnant women drank less than the recommended 2.3 L fluids/day, and 54% of women drank less than the recommended intake of 2.7 L/day during the first semester of lactation. Plain water contributed to 33% of total fluid intake, and sugar-sweetened beverages (SSB) contributed to 38% of total fluid intake. Up to 50% of pregnant and lactating women drank more than 1 L/day of SSB, which contributed to 632 kcal/day (27.5% of recommended dietary intake) and to 700 kcal/day (28% of recommended dietary intake), respectively. The high rates of overweight and obesity found in Mexican population, particularly among women, should alert us to the consumption of SSB during pregnancy and lactation, as excessive intake of these beverages may increase the risks of obesity, diabetes mellitus, and other chronic disorders.
... Generally, the role of hydration in the maintenance of health is well recognized. Even mild dehydration in a healthy adult impairs a number of important aspects of cognitive function such as concentration, alertness and shortterm memory [14]. Dehydration has been associated with dry eye in previous studies [14]. ...
... Even mild dehydration in a healthy adult impairs a number of important aspects of cognitive function such as concentration, alertness and shortterm memory [14]. Dehydration has been associated with dry eye in previous studies [14]. On the other hand, it is well established that drinking a large amount of water, especially in a short period of time, can increase the IOP and this has been approved in the water drinking test studies [15,16]. ...
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PurposeTo investigate the effects of fasting on intraocular pressure (IOP), central corneal thickness (CCT), radial peripapillary capillary (RPC) density and retinal nerve fiber layer (RNFL) thickness during Islamic fasting month of Ramadan.Methods Twenty-seven healthy fasting volunteers were enrolled. All subjects underwent full ophthalmic examination and optical coherence tomography angiography (OCTA) of both eyes. All measurements were recorded first in the morning (8:00–10:00 a.m.) and then in the evening (4:00–6:00 p.m.). The first visit was performed during the second and third week of Ramadan and then two months later in a nonfasting routine day.ResultsMean age of participants was 40.07 ± 9.29 years. A significant decrease was found for evening IOP (11.17 ± 2.29 mmHg) in comparison with morning IOP (12.00 ± 2.28) (p = 0.00) only on fasting days. A decrease was observed for CCT both on fasting (6 μm) and nonfasting days (3 μm) (p = 0.00 and p = 0.02, respectively) in the evening. There was a significant increase in whole and peripapillary RPC density (%) on fasting days (48.79 ± 3.08 morning, 49.72 ± 2.85 evening for whole and 50.57 ± 4.06 morning, 51.64 ± 3.71 evening for peripapillary) (p = 0.00). Average RNFL thickness was decreased from morning to evening both on fasting days (0.80 μm) and nonfasting days (1.25 μm) (p = 0.00). Optic nerve head (ONH) vertical cup/disc (C/D) ratio was greater on fasting days (0.30 ± 0.25 morning, 0.31 ± 0.24 evening) in comparison with nonfasting days (0.27 ± 0.25 morning, 0.28 ± 0.25 evening) (p = 0.02).Conclusion Fasting decreases the IOP and CCT in healthy subjects. OCTA revealed significant difference in RPC vessel density, RNFL thickness and ONH vertical C/D ratio during fasting hours in comparison with nonfasting days.
... Both causes of dehydration proved its adverse impact on memory and perceptual discrimination. Ritz and Berrut (2005) found that dehydration significantly reduces attention, concentration, short term memory, and increases response time as well as the feeling of tiredness and headache. Petri et al. (2006) confirmed the reduction of mental and psychomotor functions in adult, healthy individuals after voluntary 24-hour dehydration. ...
... Data for adults are not strong enough; previous studies were methodologically very heterogeneous, which does not allow their generalization (Secher and Ritz, 2012). While everyone agrees on the importance of regular intake of water, there is no consensus about how much fluid a day is necessary for optimal functioning of the body (Ritz and Berrut, 2005). According to some indicators, adult men should drink at least 2,900 ml per day and adult women 2,200 ml per day, if not exposed to heat of physical exertion (Kleiner, 1999). ...
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Various studies have shown that dehydration can lead to decrease of attention, concentration and other cognitive and motor functions, as well as the feeling of fatigue and headache. The main purpose of this study was to test if drinking water affects the student results on the Attention Test. The experiment included 91 first-year students of University for Applied Sciences VERN’. In the experimental situation participants could drink as much water as they wanted during the class, and the minimum was a few sips. In the control situation, participants did not drink water and were not allowed do so during the break. Experiments were conducted during regular classes, in two five-minute blocks, with a two minute break in between. Results did not confirm the impact of drinking water on the overall performance on the Attention Test. However, a slight but statistically significant increase in the average results was found in the experimental situation in the second five-minute measurement session.
... Mild dehydration (between 1 and 2% body water loss) is associated with negative sensations at the physiological, emotional and cognitive levels, as has been demonstrated in experimental trials with young adults where dehydration was induced with exercise and/or diuretics [8,9]. Physiologically there are sensations of thirst and oliguria [23,24]. Emotionally there are sensations of fatigue, drowsiness, body heaviness, headache, cramps, nausea, lack of enthusiasm and generalized malaise [25,26]. ...
... Emotionally there are sensations of fatigue, drowsiness, body heaviness, headache, cramps, nausea, lack of enthusiasm and generalized malaise [25,26]. At the cognitive level there are difficulties in concentration, decreased short-and long-term memory, a decrease in motor coordination and slower reflexes [23,25,27,28]. Other sensations that could be related to mild dehidration such as dry skin and constipation have not been completely demonstrated, but have been described in the clinical setting. ...
Article
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Background: Ingestion of water has been associated with general wellbeing. When water intake is insufficient, symptoms such as thirst, fatigue and impaired memory result. Currently there are no instruments to assess water consumption associated with wellbeing. The objective of our study was to develop and validate such an instrument in urban, low socioeconomic, adult Mexican population. Methods: To construct the Water Ingestion-Related Wellbeing Instrument (WIRWI), a qualitative study in which wellbeing related to everyday practices and experiences in water consumption were investigated. To validate the WIRWI a formal, five-process procedure was used. Face and content validation were addressed, consistency was assessed by exploratory and confirmatory psychometric factor analyses, repeatability, reproducibility and concurrent validity were assessed by conducting correlation tests with other measures of wellbeing such as a quality of life instrument, the SF-36, and objective parameters such as urine osmolality, 24-hour urine total volume and others. Results: The final WIRWI is composed of 17 items assessing physical and mental dimensions. Items were selected based on their content and face validity. Exploratory and confirmatory factor analyses yielded Cronbach's alpha of 0.87 and 0.86, respectively. The final confirmatory factor analysis demonstrated that the model estimates were satisfactory for the constructs. Statistically significant correlations with the SF-36, total liquid consumption and simple water consumption were observed. Conclusion: The resulting WIRWI is a reliable tool for assessing wellbeing associated with consumption of plain water in Mexican adults and could be useful for similar groups.
... Numerous studies have found negative associations between mild dehydration and several important aspects of cognitive function including short-term memory [15,36]. There is evidence that being dehydrated by just 2% leads to impaired performance in tasks that require attention, psychomotor, and immediate memory skills [37,38]. ...
... On the other hand, although women generally consume less alcohol compared to men, they usually suffer more severe brain and other organ damage following binge or chronic alcohol abuse [41]. Nevertheless, our study could not precisely calculate or estimate the exact level of hydration (as otherwise measured by bioimpedance or by the loss of body mass) and/or liquid consumption of both alcoholic and nonalcoholic drinks, but it certainly can highlight the importance of good hydration among elderly for any future investigations as older adults are particularly susceptible to mild dehydration as the total body water decreases with ageing [38], largely as a result of compromised homeostatic mechanisms such as the loss of thirst sensation and decline in renal concentrating capacity or as a result of sarcopenia, which causes a smaller fluid reserve [18,36,37,42,43]. ...
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Objectives: To investigate associations between demographic and lifestyle factors and memory performance in European people aged ≥60 years. Methods: Data from 23,641 people with a mean age of 70.2 (95 % CI 70.1-70.3) were analyzed and drawn from the fourth wave of the Survey of Health, Ageing, and Retirement in Europe (SHARE). Generalized linear models were carried out to estimate the associations for both men and women. Memory performance was tested using two word-list learning tests with immediate and delayed recall in SHARE. Results: age, severe limitations in physical activities, and any past alcohol problem were all negatively associated with memory performance. Contrarily, education level, higher nonalcoholic fluid intake, and engagement in sports activities more than once a week and in activities requiring a moderate level of energy were all positively associated with memory performance. Smoking showed a significant negative association only in the immediate recall test for both men and women together, whilst long-term illness showed association only in the delayed recall. Alcohol consumption was positively associated with memory performance in women, but in men, it depended on the drinking frequency. Conclusions: Demographic and lifestyle factors are associated with memory performance in the older population.
... The evaluation of fluid status determines further management of the disease, i.e. the decision on the method of treatment (possible hospitalization) and hydration measures (oral or intravenous route). Unfortunately, no ideal diagnostic tool that could meet the expectations of clinicians has been found to date (1,2) . ...
... decyzję o sposobie leczenia (ewentualna hospitalizacja) i nawodnienia (droga doustna czy dożylna). Niestety do tej pory nie znaleziono idealnego narzędzia diagnostycznego mogącego spełnić oczekiwania klinicystów (1,2) . ...
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Appropriate hydration is a very important prognostic factor for the patient's health. Ultrasonographic assessment of hydration status is rarely used in pediatric medicine and it is not used at all in neonates due to the fact that no reference values have been established for this age group. The aim of the paper was to establish reference values for neonates. Material and methods The study included 50 neonates from two hospitals in the Lower Silesia region of Poland; 25 of them were healthy patients (full-term newborns with no perinatal complications) and 25 were sick patients (newborns with heart defects such as ostium secundum atrial septal defect, ventricular septal defect, permanent foramen ovale and patent ductus arteriosus as well as newborns with neonatal jaundice or pneumonia that occurred during the first days of life). The ultrasound scans were conducted during the first days of the children's life. For every child inferior vena cava diameter was measured in the substernal area, longitudinal plane, M-mode in two respiratory phases: inhalation and exhalation. In addition, abdominal aorta diameter was determined (substernal area, transverse plane). Results The study demonstrated a statistically significant difference in the calculated inferior vena cava collapsibility index between both groups. Two other indices included the ratio of the inferior vena cava diameter during the expiratory phase to the diameter of the aorta and the ratio of the inferior vena cava diameter during the inspiratory phase to the diameter of the aorta; a statistically significant difference between both groups was found only for the measurements in the inspiratory phase. Conclusions Based on the study results normal ranges for hydration indices in neonates were established. The need for the measurement of the abovementioned parameters in the inspiratory phase was determined. In addition, the usefulness of the ultrasound examination for the evaluation of body fluid status in this pediatric age group, particularly in preterm newborns, was noted due to its painless and non-invasive nature as well as easy access to equipment at neonatology wards.
... tissues and organs and thus it is vital for life (Jéquier and Constant, 2009). According to Ritz and Berrut (2005), water acts as our bodies' regulator, as it maintains important aspects of our bodies such as the vascular size and the circulation of blood. All organs and tissues of the body cannot function without it. ...
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Many rural communities of South Africa are living without adequate water supplies mainly due to historical lack of infrastructure and effective water reticulation systems. Day to day challenges of accessing water from distant boreholes and rivers are a reality particularly for women and children in rural Limpopo. This study investigates the nature and extent of water supply problems and how communities are living without adequate water in three rural communities of Greater-Giyani Local Municipality in South Africa. The study area lies in a semi-arid region which regularly experiences climate extremes such as droughts and floods which can reduce the ability of the municipality to supply water. Primary data was collected through questionnaires, key informant interviews and field observations while population, climate and hydrological data are also analyzed. A mixed methods research design was employed using qualitative methods such as content analysis whilst quantitative methods were dominated by time series analysis techniques and online interactive climate platforms such as the Climate Engine. It was found that households, schools and clinics in the study area rely mainly on boreholes for water supply but sometimes rivers supply those living nearby. An incomplete and poor water reticulation system coupled with erratic and shortening summer rainfall seasons are some of the major causes of water shortages in the study area. In order to cope with inadequate water, community members and public institutions in the study area have drilled boreholes and the sustainability of groundwater in the area is not well established. During summer, most households and institutions practise rainwater harvesting while a few resort to purchasing water from vendors. Despite these challenges which are not well documented, it was concluded that most of the rural poor households and institutions in the study area are well adapted to cope with water scarcity in the short term, while being vulnerable in the long term due to population growth and climate change. The study recommends the need for government and municipalities to invest in water reticulation systems in the long term whilst providing water to affected rural communities through water tankers, drilling more boreholes and maintenance of existing ones. Lessons learnt from this study may be useful to other municipalities across South Africa that are grappling with challenges of water access and supply. Keywords: Water resources, water supply, water scarcity, water resources, changing climate, coping strategies, Greater-Giyani Local Municipality.
... Dehydration has been shown to be potentially associated with suboptimal cognitive and physical performance in both adults and children. [4][5][6][7][8] Children's fluid requirements vary as a function of gender and age. Gender, age clusters, and definitions of recommended daily water intakes vary widely between countries. ...
Article
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Background. Children who drink too little to meet their daily water requirements are likely to become dehydrated, and even mild dehydration can negatively affect health. This is even more important in Middle-Eastern countries where high temperatures increase the risk of dehydration. We assessed morning hydration status in a sample of 519 Egyptian schoolchildren (9-11 years old). Methods. Children completed a questionnaire on breakfast intakes and collected a urine sample after breakfast. Breakfast food and fluid nutritional composition was analyzed and urine osmolality was measured using osmometry. Results. The mean urine osmolality of children was 814 mOsmol/kg: >800 mOsmol/kg (57%) and >1000 mOsmol/kg (24.7%). Furthermore, the results showed that a total water intake of less than 400 mL was associated with a significant higher risk of dehydration. Surprisingly, 63% of the children skipped breakfast. Conclusions. The results showed that a majority of Egyptian schoolchildren arrive at school with a hydration deficit. These results highlight the fact that there is a need to educate schoolchildren about the importance of having a breakfast and adequate hydration.
... Adequate fluid intake plays an important role in maintaining water balance, and dehydration may occur when the water balance is broken. It has been reported that dehydration is associated with urological, gastrointestinal, circulatory, and neurological disorders [3][4][5][6]. Even mild dehydration has an adverse impact on cognitive and performance functions, and elderly people are vulnerable to water deficit [6,7]. ...
Article
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Background: Dehydration due to insufficient fluid intake (IFI) is detrimental to health. This cross-sectional study aimed to assess the fluid intake of urban adults in Wuxi, China, and to identify potential risk factors contributing to IFI. Methods: Adults were selected from the urban area of Wuxi, China, using a multiple-stage random sampling method. The fluid intake information was obtained with a 24-h self-reported diary over seven consecutive days in both summer and winter of 2015. A classification and regression tree (CART) analysis was conducted to detect the potential risk factors associated with IFI. CART is a machine-learning algorithm that portions the data into subsets by threshold. Results: A total of 584 adults aged 18-87 years were included. The results showed that the median (P25-P75) values of daily fluid intake of the participants were 1100 (800-1550) mL in summer and 1000 (750-1300) mL in winter. Women had a higher prevalence of IFI than men in both summer (odds ratio (OR) = 2.683, 95% confidence interval (CI): 1.830-3.934) and winter (OR = 2.636, 95% CI: 1.677-4.142). The results of CART analysis showed that, in summer, BMI < 25 kg/m2 (probability: 64.2%) and age < 64 years (probability: 67.4%) were main risk factors of IFI for men, and BMI < 29 kg/m2 (probability: 81.6%) and living in C Community (probability: 86.7%) were main risk factors for women. In winter, age < 40 years (probability: 81.8%) and BMI < 20 kg/m2 (probability: 94.5%) were identified as main risk factors of IFI for men and women, respectively. Conclusions: Most of the participants living in the study site had IFI. The fluid consumption varied by gender, age, location, and BMI. The findings could be useful for the implementation and optimization of intervention programs by identifying the individuals who may at greater risk of dehydration.
... Finally, hypohydration has been shown to impair cognitive functions, such as alertness, short-term memory, concentration, arithmetic efficiency, psychomotor processing, and attention, and increase headaches and tiredness (Cian et al. 2000(Cian et al. , 2001Neave et al. 2001;Shirreffs et al. 2004;Suhr et al. 2004;Ritz and Berrut 2005). The Cr/Gly hyperhydrating protocol developed by Easton et al. (2007) has been successfully applied to counter orthostatic intolerance in male subjects undertaking a postural tilt test, whereby subjects lay supine for 30 min before being tilted headup to 70° for a further 30 min or until the limit of tolerance (Easton et al. 2009). ...
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Creatine (Cr) is produced endogenously in the liver or obtained exogenously from foods, such as meat and fish. In the human body, 95 % of Cr is located in the cytoplasm of skeletal muscle either in a phosphorylated (PCr) or free form (Cr). PCr is essential for the immediate rephosphorylation of adenosine diphosphate to adenosine triphosphate. PCr is rapidly degraded at the onset of maximal exercise at a rate that results in muscle PCr reservoirs being substantially depleted. A well-established strategy followed to increase muscle total Cr content is to increase exogenous intake by supplementation with chemically pure synthetic Cr. Most Cr supplementation regimens typically follow a well-established loading protocol of 20 g day(-1) of Cr for approximately 5-7 days, followed by a maintenance dose at between 2 and 5 g day(-1) for the duration of interest, although more recent studies tend to utilize a 0.3-g kg(-1) day(-1) supplementation regimen. Some studies have also investigated long-term supplementation of up to 1 year. Uptake of Cr is enhanced when taken together with carbohydrate and protein and/or while undertaking exercise. Cr supplementation has been shown to augment muscle total Cr content and enhance anaerobic performance; however, there is also some evidence of indirect benefits to aerobic endurance exercise through enhanced thermoregulation. While there is an abundance of data supporting the ergogenic effects of Cr supplementation in a variety of different applications, some individuals do not respond, the efficacy of which is dependent on a number of factors, such as dose, age, muscle fiber type, and diet, although further work in this field is warranted. Cr is increasingly being used in the management of some clinical conditions to enhance muscle mass and strength. The application of Cr in studies of health and disease has widened recently with encouraging results in studies involving sleep deprivation and cognitive performance.
... [27][28][29] La falta de agua corporal o deshidratación aguda afecta los procesos cognitivos, provoca estados de ánimo variables, disminuye la regulación térmica, reduce la función cardiovascular y afecta la capacidad para el trabajo físico. 17,[30][31][32][33][34][35] Por otro lado, se ha documentado que la deshidratación crónica eleva el riesgo de cáncer de la vejiga. 17,36,37 El agua potable carece casi por completo de efectos adversos en los individuos sanos cuando se consume en los intervalos de valores aceptados y no provee energía; por estas razones se considera la elección más saludable para lograr una adecuada hidratación. ...
Article
The Expert Committee in charge of developing the Beverage Consumption Recommendations for the Mexican Population was convened by the Ministry of Health with the aim of drafting evidence-based guidelines for consumers, health professionals, and government officials. The prevalence of overweight, obesity and diabetes have dramatically increased in Mexico: beverages contribute a fifth of all calories consumed by Mexicans. Extensive research has documented that caloric beverages increase the risk of obesity. Taking into consideration multiple factors, including health benefits, risks, and nutritional implications associated with beverage consumption, as well as consumption patterns in Mexico, the committee classified beverages in six categories. Classifications were made based on caloric content, nutritional value, and health risks associated with the consumption of each Ope of beverage. Ranges included healthier (level 1) to least healthy (level 6) options as follows: Level 1: water; Level 2: skim or low fat (1%) milk and sugar free soy beverages; Level 3: coffee and tea without sugar: Level 4: non-caloric beverages with artificial sweeteners: Level 5: beverages with high caloric content and limited health benefits (fruit juices, whole milk and fruit smoothies with sugar honey; alcoholic and sports drinks), and Level 6: beverages high in sugar and with low nutritional value (soft drinks and other beverages with significant amounts of added sugar like juices, flavored waters, coffee and tea). The committee recommends the consumption of water as a first choice, followed by no or low-calorie drinks, and skim milk. These beverages should be favored over beverages with high caloric value or sweetened beverages, including those containing artificial sweeteners. Portion size recommendations are included for each beverage category together with healthy consumption patterns for men and women.
... Increased blood viscosity due to hemoconcentration is positively correlated with coronary heart disease [36,37]. It has been suggested that appropriate hydration can play an important role in the day-to-day health [38] and the prevention of various chronic diseases, including cardiovascular disease [1,39]. Based on the present findings, hypohydration-related alteration in endothelial function might play a role in the risk of CVD. ...
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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.
... These expenses can be charged to an overhead or trust account (12). The effects of dehydration on cognitive function have been studied in several randomized controlled clinical trials, in which dehydration was achieved by fluid restriction, heat exposure, exercise, or combinations thereof (27). In healthy young adults, dehydration to 2.8% body weight loss by heat exposure or exercise significantly decreased alertness, concentration, tracking performance, and short-term memory and increased tiredness, headaches, and reaction time (28). ...
... Hydration/dehydration in children: Optimal hydration status is essential for adequate physical and mental functioning [5]. Fluid requirements relative to body weight are greatest during the neonatal period and throughout childhood: infants and children retain water for growth and have higher non-renal water losses because of a higher body surface area related to body mass [6]. ...
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It is a commonplace that water is essential for life, but to what extent is the general public, and children in particular, aware of how water affects health? The aim of this review was to consider the relationship between water and health under three main headings: the importance of hydration for children, dietary intake of water, and water as an essential factor in hygiene contributing to good health. The literature was reviewed to provide a rationale for the implementation of teaching about water and health in French primary schools under three main areas: (i) the importance of hydration for school children and water promotion in primary schools; (ii) the problem of overweight/obesity and the need to adopt healthy drinking habits as defined in French nutritional policy; (iii) the survey of the quality of drinking water in France and its relationship with good hygiene practices. There are currently few educational resources in France on water and health that teachers can use in the classroom. This review gives reasons why a “Water and Health” learning resource is a useful tool and shows how it can be developed within the constraints imposed by the school syllabus and in accordance with French nutritional and environmental policy.
... A study in healthy adults shows that even mild dehydration impairs a number of important aspects of cognitive function. 2 A substantial proportion of the population is chronically dehydrated, and even mild dehydration may be a cause of many health problems, including dry eyes. 3 Many people drink large volumes of coffee, tea, alcohol and sodas that act as diuretics and can bring on a dehydrated state. ...
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Aim: To investigate the effect of dehydration on intraocular pressure (IOP). Subjects: The study population comprised 50 subjects (27 men and 23 women) with a mean age of 42.84 ± 2.64 years.Method: The subjects dehydrated for 18 hours. IOP was assessed in both eyes using the Perkins handheld applanation tonometer. Baseline measurement of IOP was taken before the subjects dehydrated for 18 hours and repeated after dehydration. Blood samples were taken before and after dehydration for the determination of plasma osmolality and plasma antidiuretic hormone (ADH) concentrations.Results: A statistically significant (p < 0.001) reduction in the mean weight of subjects occurred after dehydration. There was a significant reduction in IOP from 16.68 mmHg ± 0.32 mmHg to 13.08 mmHg ± 0.31 mmHg after dehydration (p < 0.001). Mean plasma osmolality showed a statistically significant increase (p < 0.05) from baseline of 290.02 mOsmol/kg ± 1.25 mOsmol/kg to 294.96 mOsmol/kg ± 1.33 mOsmol/kg after dehydration. There was also a significant increase (p < 0.05) in mean plasma ADH concentration from 5.36 pg/mL ± 0.21 pg/mL to 6.40 pg/mL ± 0.20 pg/mL after dehydration. There were no significant differences in both systolic and diastolic blood pressures before and after dehydration.Conclusion: Dehydration decreases IOP in healthy humans; this decrease probably results from an increase in plasma osmolality and plasma ADH concentrations.
... The physiological processes previously mentioned could have been triggered by the intervention through sessions of concurrent motor games, and these mechanisms, at the same time, could have been optimized by the hydration strategy given by the methodological proposal. Ritz & Berru [39] indicate that a eu-hydration status can promote the mobilization, transportation, and use of fatty acids by the muscular tissue during an exercise session. ...
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Concurrent training of strength and endurance has been widely ued in the field of health, with favorable effects on body composition. However, the effect on the body composition of a ludic-motor concurrent proposal in adults with Down syndrome has not been quantified yet. The aim of this study was to determine the effect of a concurrent training program based on motor games on body composition indicators and cardiometabolic risk on schooled male adults with Down syndrome. Methods: The sample is composed of 15 male adults with Down syndrome from Chile. Body composition variables such as body mass index, waist circumference, height to waist ratio, skin folds, perimeters, and muscle areas were assessed at the beginning and end of the program. Subsequently, a program of motor games was designed and implemented for 10 months. Results: Mean and standard deviation for body fat were pre (25.36 ± 5.60) and post (23.01 ± 6.20)%; waist circumference pre (86.00 ± 8.97) and post (82.07 ± 8.38) cm. Brachial perimeter and muscle area were pre (22.30 ± 2.80) and post (23.61 ± 2.28) cm; pre (40.19 ± 10.09) and post (44.77 ± 8.48) cm 2 , respectively. Our findings showed significant results (p < 0.05): body fat %; sum of folds; waist circumference; height to waist ratio; brachial perimeter and brachial muscle area. Conclusion: A concurrent training program implemented through motor skills games decreases body fat and cardiovascular risk and increases the muscle mass in male adults with Down syndrome.
... The amount of body water is very tightly controlled and even small increases in serum osmolality will stimulate thirst and secretion of antidiuretic hormone (ADH) to increase renal concentrating capacity, whereas decreased osmoconcentration will result in increased, more dilute urine production. Severe dehydration is fatal but even mild dehydration equating to a 1-2% loss of bodyweight leads to headaches, fatigue and reduced physical and mental performance (Shirreffs et al. 2004;Ritz & Berrut 2005;Shirreffs 2005). Chronic mild dehydration is associated with constipation, urinary tract infections, coronary heart disease and stroke (Manz & Wentz 2005). ...
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After water, tea is the most commonly consumed beverage worldwide, with over 80% of adults drinking tea in the UK. Lay concerns about caffeine have led to questions about the suitability of tea as a source of hydration. Several controlled trials have examined the effect of moderate caffeine consumption on fluid balance, from tea or other sources, concluding that intakes of up to 400 mg of caffeine, or six to eight servings of tea daily, are consistent with normal hydration. Unlike water, or other caffeinated beverages, tea is rich in flavonoids: plant compounds associated with health. There is now a growing body of evidence linking regular tea consumption with heart health, cognitive health, dental benefits and bodyweight management suggesting that tea may offer a healthy source of hydration. These studies are discussed in the context of typical tea intakes in the UK.
... 6,7 Water is the environment in which all transport systems work. 8 It helps in maintaining body volume (intracellular and extracellular), 9,10 which is essential to prevent dehydration, a potentially life-threatening condition. 11 The water in the body also plays an important role in thermoregulation 10 and acts as a lubricant and shock absorbent. ...
Article
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It is generally assumed that dietary water might be beneficial for the health, especially in dermatological (age preventing) terms. The present study was designed to quantify the impact of dietary water on major indicators of skin physiology. A total of 49 healthy females (mean 24.5±4.3 years) were selected and characterized in terms of their dietary daily habits, especially focused in water consumption, by a Food Frequency Questionnaire. This allowed two groups to be set – Group 1 consuming less than 3,200 mL/day (n=38), and Group 2 consuming more than 3,200 mL/day (n=11). Approximately 2 L of water were added to the daily diet of Group 2 individuals for 1 month to quantify the impact of this surplus in their skin physiology. Measurements involving epidermal superficial and deep hydration, transepidermal water loss, and several biomechanical descriptors were taken at day 0 (T0), 15 (T1), and 30 (T2) in several anatomical sites (face, upper limb, and leg). This stress test (2 L/day for 30 days) significantly modified superficial and deep skin hydration, especially in Group 1. The same impact was registered with the most relevant biomechanical descriptors. Thus, in this study, it is clear that higher water inputs in regular diet might positively impact normal skin physiology, in particular in those individuals with lower daily water consumptions. Keywords: dietary water, water consume, skin hydration, TEWL, skin biomechanics
... Hydration has a vital role in our lives. Inadequate water intake leads to physiological and psychological problems such as headache, fatigue, infections and stress (Jéquier and Constant, 2010;Palma et al., 2015;Ritz and Berrut, 2005). Our bodies exhibit self-response mechanisms, like sensing the thirst (Greenleaf, 1992) or having a dry mouth, yet these only help in the case of deficiency, thus not reliable in keeping a balanced hydration level. ...
Article
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Taking on the challenge of motivating users to drink water regularly, we designed a smart water bottle that can track water intake behavior and inform users about this behavior through ambient feedback. We then conducted two studies to explore the bottle's feedback design from the perspective of users and designers. First, we conducted semi-structured interviews with 10 prospective users and found that they would like to receive personalized, precise, gamified and reminding feedback. Second, we conducted a design workshop with 13 professional designers to explore the range of visualizations that can be used to give feedback. Analyzing these visualizations, we identified three reminder types (augmenting, restoring and balancing) and six visualization styles grouped according to three dimensions of ambient displays (representation fidelity, notification level, aesthetic emphasis). In this paper, we first explain our water bottle concept along with existing solutions. Then, we report the results of these studies. Finally, we discuss the potential implications of the results for our own work as well as for designing ambient displays aimed at supporting users' water intake tracking practices.
... The proximal small intestine absorbs fluids with a capacity of up to 15 L/day (Ritz & Berrut 2005). A number of reasons cause constipation, which is characterized by slow gastrointestinal transit and difficulty in passing stool. ...
Thesis
Water intake is crucial for maintaining body fluid homeostasis and animals’ survival. Complex brain processes trigger thirst, which arises upon losing blood volume (i.e. extracellular dehydration) or increasing blood osmolality (i.e. intracellular dehydration), to replenish water for fluid balance. The brain plays a key role in modulating these processes, but the central mechanisms regulating water intake are not fully understood. Type-1 cannabinoid receptors (CB1) are widely and abundantly expressed in the central nervous system where they modulate a variety of functions, such as memory, anxiety and feeding behavior. However, the role of CB1 receptors in the control of water intake is still a matter of debate, since pharmacological activation or blockade of CB1 receptors produced contradictory results in drinking behavior experiments.My thesis work focuses on the role of CB1 receptors in the control of water intake. By using genetic, pharmacological, anatomical, imaging, and behavioral approaches, I examined the involvement of CB1 receptors in the control of water intake induced by different physiological conditions of extracellular or intracellular dehydration. The results showed that CB1 receptor signaling is required to promote water intake. In particular, global deletion of CB1 receptors does not change plasma osmolality and body water composition, but it decreases water intake induced by water deprivation, systemic or intracerebroventricular (ICV) administration of sodium chloride, or ICV injection of the peptide hormone angiotensin II. In the attempt to better detail the neuronal mechanisms of this function, I discovered that the presence of CB1 receptors in cortical glutamatergic neurons, particularly the ones located in the anterior cingulate cortex (ACC) glutamatergic neurons promote drinking behavior. CB1 receptors are abundantly expressed in axon terminal of ACC glutamatergic neurons projecting to the basolateral amygdala (BLA) and selective expression of CB1 receptors in this circuit is sufficient to guarantee proper drinking behavior in mice. Altogether, these data reveal that CB1 receptors are necessary to promote water intake, and that their presence in the ACC-BLA circuit is sufficient for the top-down control of drinking behavior.Furthermore, I also provided evidence that CB1 controls water intake in different conditions at other levels, e.g. insular cortex, cholinergic cells, and mitochondria.In summary, my thesis work analyzed the role of CB1 receptors in distinct cell populations/neuronal circuits for the control of water intake. These results will help further understanding the functions of the ECS and the brain regulation of thirst.
... There is a concern that total water intake in the studied 6-year-olds may be inadequate. Low intake of water is unfavourable since water is not only essential for day-today health [69] but may also play a role in the prevention of chronic diseases [70]. It is probable that parents underestimated the role of this macronutrient because they often hear in the Polish mass media about the importance of protein, vitamins or minerals to the health of their children, but rarely attention is drawn to the importance of water. ...
Article
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Background The studies on dietary intake in Polish children are sparse and the information about dietary intake in 6-year-olds in Europe is limited. The published studies on dietary intake in children rarely provide information on the intake of animal protein, plant protein and water. The purpose of the study was to analyse energy and macronutrient intakes in 6-year-old children from southern Poland. Methods The studied population comprised 120 children, 64 girls and 56 boys. Energy and macronutrient intakes were estimated from a three-day food record. Weight and height were measured, and body mass index was calculated. Results Intakes of energy (kJ, kcal), plant protein (g), total fat (g), saturated fatty acids (g, % of energy, g/1000 kcal), monounsaturated fatty acids (g) and starch (g, % of energy, g/1000 kcal) were significantly higher in boys, while intakes of sucrose (% of energy, g/1000 kcal) and total water (g/1000 kcal) were significantly higher in girls. The children’s diets were characterised by excessive intake of total fat, saturated fatty acids, sucrose, and by inadequate intake of polyunsaturated fatty acids, available carbohydrates and starch. Conclusions The observed adverse characteristics of the children’s diets are similar to those observed in the diets of children in other European countries and show the need to work out a common educational programme to improve nutrition in young European children. It is also important to provide the lacking information about the intake of animal protein, plant protein and water in young children.
... An adequate hydration is critical for a series of body functions, including proper regulation of core body temperature, elimination of waste metabolites by the kidney and maintenance of normal physical and cognitive functions [1][2][3] . Some institutions have set an adequate intake (AI) for total water intake (water from food and from fluids), but these recommendations vary widely. ...
Article
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Introduction: An adequate hydration is critical for a series of body functions, including proper regulation of core body temperature, elimination of waste metabolites by the kidney and maintenance of normal physical and cognitive functions. Some institutions have set recommendations for adequate intake of water, but these recommendations vary widely. Objective: To estimate the usual daily consumption of fluids (water and all other beverages) by a selective sample of Mexican population. Methods: Cross-sectional sample of 1,492 male and female adults between 18-65 years of age, drawn from 16 cities throughout Mexico. Self-reported fluid intake data collected over a 7-day consecutive period, recording intake of water, milk and derivatives, hot beverages, sugar sweetened beverages (SSB), alcoholic beverages and others. Results: We found that 87.5% of adult males and 65.4% of adult females reported drinking below their recommended daily fluid intake (3 L for males and 2 L for females), and in 80% of the population SSB, not including hot beverages or milk and derivatives, accounted for a larger amount and proportion of fluid intake than plain water. Sixty-five percent of adult males and 66% of adult females consumed more than 10% of their estimated daily caloric intake from fluids. Fluid intake did not differ significantly by gender, but showed a declining trend with age. Conclusion: Our findings may have important implications for policy recommendations, as part of comprehensive strategies to promote the adoption of healthy life styles, in this case, promoting consumption of plain water while discouraging excessive consumption of caloric beverages.
... Deficits in hydration levels of as little as 1-2% have been shown to have detrimental effects on endurance, thermoregulatory capability, and motivation and to increase fatigue and perceived effort. 9,30,31 Heart rate is increased, muscle power is decreased, physiological strain is greater, and cognitive performance is reduced. 9,14,32 Activities requiring highintensity and endurance have been reported to be particularly susceptible to fluid deficits. ...
Article
Objectives To examine the current state of the science regarding the role of systemic hydration in vocal function and health. Study Design Literature review. Methods Literature search spanning multiple disciplines, including speech-language pathology, nutrition and dietetics, medicine, sports and exercise science, physiology, and biomechanics. Results The relationship between hydration and physical function is an area of common interest among multiple professions. Each discipline provides valuable insight into the connection between performance and water balance, as well as complimentary methods of investigation. Existing voice literature suggests a relationship between hydration and voice production; however, the underlying mechanisms are not yet defined and a treatment effect for systemic hydration remains to be demonstrated. Literature from other disciplines sheds light on methodological shortcomings and, in some cases, offers an alternative explanation for observed phenomena. Conclusions A growing body of literature in the field of voice science is documenting a relationship between hydration and vocal function; however, greater understanding is required to guide best practice in the maintenance of vocal health and management of voice disorders. Integration of knowledge and technical expertise from multiple disciplines facilitates analysis of existing literature and provides guidance as to future research.
... Viele Studien belegen, dass die kognitiven Fähigkeiten durch Dehydration beeinträchtigt sind. Dabei ist zu beachten, dass die Probanden durch Maßnahmen wie Hitzeeinwirkung, Flüssigkeitsentzug und körperliche Betätigung akut dehydriert wurden[24]. In Zeitschri en mit Peer-Review-Verfahren wurden bisher keine Untersuchungen publiziert, welche die kognitiven Leistungen von Personen, die vom Durst geleitet trinken, mit denen unter forcierter Flüssigkeitsaufnahme vergleichen.Kosmetische E ekteAuch positive E ekte des vermehrten Trinkens auf die Haut werden postu-liert. ...
Article
Tausende Jahre trank der Mensch dann, wenn er Durst hatte. Erst Ende des vergangenen Jahrhunderts verbreitete sich die Annahme, dass für einen optimal funktionierenden Organismus eine forcierte Flüssigkeitszufuhr erforderlich sei. Der darauf ausgesprochenen Empfehlung, viel zu trinken, wurde massenhaft gefolgt und die stets griffbereite Trinkflasche zu einem unverzichtbaren Utensil. Doch welche wissenschaftlichen Daten belegen überhaupt die Vorteile einer gesteigerten Flüssigkeitszufuhr?
... 9 Among adults, a number of studies demonstrate that dehydration, induced by physical activity, heat exposure, or fluid restriction, impairs cognitive performance. 10,11 These impairments were observable at a dehydration-induced loss of just 2% body weight or more. ...
Article
Background: Evidence suggests that an insufficient fluid intake impairs cognitive performance. Drinking policies at schools-especially drinking during lessons-is a point of controversy. To provide a scientific base for this debate, more empirical evidence is needed on which aspects of fluid intake are crucial for cognitive performance. This study makes a contribution by investigating associations between quantitative and temporal aspects of fluid intake and cognitive performance in everyday school life. Methods: The study comprised 125 children (age: mean = 10.98 years, SD = 0.38). Amount of fluid intake and time span between fluid intake and completion of cognitive tests were determined on basis of self-reports. Cognitive performance was assessed by standardized tests. Results: Quantitative and temporal aspects were associated with cognitive performance: The more fluid the children consumed and the shorter the time span between their last fluid intake and test completion, the better they performed. Conclusions: The amount of fluid intake should be adequate and moreover the time span between intake and cognitive efforts should be as short as possible. Schoolchildren are thus recommended to drink at regular intervals and also during lessons.
... Water is often referred to as the 'element of life'. It serves as nutritional source [Popkin et al., 2010, Ritz and Berrut, 2005, Self and Waskom, 1992, as a habitat for various animals [Alava et al., 2012, Samuel et al., 2005, Freeman et al., 2013 or can simply be used to maintain hygiene and therefore avoid several diseases [Mara, 2003, Ashbolt, 2004, Pengpid and Peltzer, 2012, Curtis, 2007, Matta and Kumar, 2017. That is, every living being on our planet needs water to survive. ...
Preprint
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Among the seventeen Sustainable Development Goals (SDGs) proposed within the 2030 Agenda and adopted by all the United Nations member states, the 13$^{th}$ SDG is a call for action to combat climate change for a better world. In this work, we provide an overview of areas in which audio intelligence -- a powerful but in this context so far hardly considered technology -- can contribute to overcome climate-related challenges. We categorise potential computer audition applications according to the five elements of earth, water, air, fire, and aether, proposed by the ancient Greeks in their five element theory; this categorisation serves as a framework to discuss computer audition in relation to different ecological aspects. Earth and water are concerned with the early detection of environmental changes and, thus, with the protection of humans and animals, as well as the monitoring of land and aquatic organisms. Aerial audio is used to monitor and obtain information about bird and insect populations. Furthermore, acoustic measures can deliver relevant information for the monitoring and forecasting of weather and other meteorological phenomena. The fourth considered element is fire. Due to the burning of fossil fuels, the resulting increase in CO$_2$ emissions and the associated rise in temperature, fire is used as a symbol for man-made climate change and in this context includes the monitoring of noise pollution, machines, as well as the early detection of wildfires. In all these areas, computer audition can help counteract climate change. Aether then corresponds to the technology itself that makes this possible. This work explores these areas and discusses potential applications, while positioning computer audition in relation to methodological alternatives.
... With increasing life spans and an increasingly larger aged population globally, the necessity to better understand the physiological and behavioral changes that occur with aging is growing. Maintenance of euhydration and renal handling of water (H 2 O) and electrolyte loads is one such physiological process that may be altered with aging (5,9,19) and is essential for normal cardiovascular, cognitive, and digestive function (22). Under ad libitum conditions in a natural environment, healthy, free-living older adults consume enough fluids with meals to maintain adequate hydration. ...
Article
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Aging is associated with altered water, electrolyte, and glucose handling. Alternative beverages to those containing carbohydrate (CHO) should be considered for older adults. We hypothesized that reduced sodium (CNa+) and/or water (CH2O) clearance would underlie greater beverage retention in older compared to young adults, secondary to reduced glomerular filtration rate (GFR). We further hypothesized that amino acid (AA)- and CHO-based beverages would promote retention better than water. Over 5 visits, 12 young (23±3y, 7M/5F) and 12 older (67±6y, 5M/7F) subjects consumed 1 L of distilled water or beverages with 6% CHO, 0.46 g/L Na+ (GAT), 2.5% CHO, 0.74 g/L Na+ (PED), 5 AA, 1.04 g/L Na+ (ENT-5), or 8 AA, 1.38 g/L Na+ (ENT-8) over 30 min. Blood and urine were collected every hour for 4h post-ingestion; retention, CH2O, and CNa+ were calculated at 2h and 4h. Additional calculations adjusted CH2O and CNa+ for estimated GFR (eGFR). Water yielded the lowest retention in both groups ( p≤0.02). Retention was higher in older vs. young except in ENT-8 at 4h ( p=0.73). CH2O was higher for older vs. young in GAT 2h ( p<0.01), and GAT and PED 4h ( p<0.01), post-ingestion, but was otherwise similar between groups. CNa+ was lower in older vs. young except in ENT-8 ( p≥0.19). Adjusting for eGFR resulted in higher CH2O for all beverages in older vs. young ( p<0.05), but did not influence CNa+. Older adults may better retain beverages with less Na+ than young adults due to reduced CNa+. AA- and CHO-based, electrolyte-rich beverages may similarly promote beverage retention.
... Mild dehydration happens to people with sedentary lifestyles and occupations [2], which increases body weight and risk of chronic diseases [3,4]. Furthermore, inadequate fluid intake decreases physical and mental functions [5], and leads to negative health consequences, such as headache, dizziness and urolithiasis [6,7]. Therefore, fluid intake management is critical to assist people to manage individual drinking behaviors. ...
Article
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Fluid intake is important for people to maintain body fluid homeostasis. Inadequate fluid intake leads to negative health consequences, such as headache, dizziness and urolithiasis. However, people in busy lifestyles usually forget to drink sufficient water and neglect the importance of fluid intake. Fluid intake management is important to assist people in adopting individual drinking behaviors. This work aims to propose a fluid intake monitoring system with a wearable inertial sensor using a hierarchical approach to detect drinking activities, recognize sip gestures and estimate fluid intake amount. Additionally, container-dependent amount estimation models are developed due to the influence of containers on fluid intake amount. The proposed fluid intake monitoring system could achieve 94.42% accuracy, 90.17% sensitivity, and 40.11% mean absolute percentage error (MAPE) for drinking detection, gesture spotting and amount estimation, respectively. Particularly, MAPE of amount estimation is improved approximately 10% compared to the typical approaches. The results have demonstrated the feasibility and the effectiveness of the proposed fluid intake monitoring system.
... Anaerobic performance has been shown to be impaired during both single and repeated bouts of anaerobic exercise with moderate levels of dehydration (87). However, during anaerobic exercise lasting less than 30 seconds, there seems to be no effect of hypohydration on performance (107). It is difficult to interpret the results of the effects of hydration on anaerobic performance due to both exacerbating (caloric restriction, increased muscle temperature and fatigue) and masking (endurance training, test type, and menstrual status) factors within the methodological protocols, making it challenging to isolate the effects of dehydration on anaerobic performance alone (101). ...
Article
Maintaining an appropriate level of hydration has been shown to optimize performance and enhance safety during exercise in the heat. However, limited research exists examining the influence of exercise-induced dehydration on quality of sleep and measures of aerobic capacity and neuromuscular control. The purpose of this investigation sought to examine quality of sleep, aerobic capacity and neuromuscular control following prolonged exercise in the heat. Eleven participants (mean±SD; age, 22±3y; height, 178±6cm; VO2max, 54.3±5.4ml•kg-1•min-1; body fat, 11.6±3.9%) completed three exercise sessions in a climate-controlled chamber (ambient temperature, 35.3±0.6°C, relative humidity, 31.3±2.0%). Exercise consisted of 3 hours of exercise on a motorized treadmill followed by 60 minutes of passive rest in a climate-controlled chamber. Neuromuscular control and hematologic hydration measures were assessed before and after each exercise session. Objective and subjective sleep measures along with 24-hour urine were collected the night before and after the exercise session. Participants also arrived to the laboratory 24-30 hours the following day for assessment of hydration status via urinary and hematologic measures and measurements of aerobic capacity and neuromuscular control. Trials consisted of: 1) Participants arrived euhydrated and minimized their fluid losses during exercise and recovery (EUR), 2) Participants arrived euhydrated and progressively dehydrated during exercise and recovery (EUD), and 3) Participants arrived hypohydrated and progressively dehydrated during exercise and recovery (HYD). At the end of exercise, the level of hypohydration was 0.4±1.0%, 3.8±1.2% and 5.6±0.6% for EUR, EUD and HYD respectively. There were no differences in hydration status as measured by changes in body mass, urinary and hematologic markers between trials or rehydration groups the day following the exercise session of each trial. There were no differences between trial or rehydration group on objective or subjective measures of sleep; however, urine volume was predictive of improved subjective ratings of sleep. Additionally, there were no differences in measures of aerobic capacity or neuromuscular control between trials or rehydration groups the day following each exercise session. Moderate intensity exercise in the heat eliciting graded levels of hypohydration does not seem to adversely affect quality of sleep or neuromuscular control when assessed 24 hours following exercise.
... Álvarez, Martin, García-García, Cuesta y Carrasco, 2020): comer 4-5 veces al día, consumo diario de proteínas, fruta y verdura, lácteos, frutos secos naturales) y de la hidratación en periodo no deportivo (Ritz y Berrut, 2005): consumir 1,5-2 litros de líquido más la correspondiente durante las comidas). Estas consignas estarán en coordinación del nutricionista o médico deportivo. ...
... Water is essential for life and is the main constituent of cells, tissues and organs (Lang and Waldegger, 1997). It can greatly influence the fitness of an organism because of its compulsory role as a solvent for other macronutrients (Jéquier and Constant, 2010), modulation of cell-tocell signaling (Grandjean and Campbell, 2004) and capacity to maintain the function of all tissues and organs in an organism (Ritz and Berrut, 2005). Clearly, the importance of water balance to homeostasis in most vertebrates cannot be overstated; in some taxa, an absence of water can be lethal within days (Popkin et al., 2010). ...
Article
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Immune function can vary based on availability of resources, and most studies of such influences have focused on the co-investment of energy into immune and other physiological functions. When energy resources are limited, trade-offs exist, which can compromise immunity for other functions. As with energy, water limitation can also alter various physiological processes, yet water has received little consideration for its role in possibly modulating immune functions. We examined the relationship between immunocompetence and hydration state using the western diamond-backed rattlesnake (Crotalus atrox). This species is known to undergo substantial seasonal fluctuations in water availability with extreme limitations during the hot, dry season. We collected blood samples from free-ranging C. atrox to compare osmolality and innate immune function (lysis, agglutination, bacterial growth inhibition) during the milder and relatively moister early spring season, the hot-dry season, and the hot-wet season. To isolate effects of dehydration from other possible seasonal influences, we complemented this field study with a laboratory study in which we withheld food and water from individually housed adult C. atrox for up to 16 weeks. We collected blood samples from each snake as it dehydrated and collected a final sample after the snake was given ad lib water at the end of the experiment. Our results demonstrate that C. atrox experience significant dehydration during the hot-dry season, and that, in general, innate immune function is highly correlated with osmolality, whether natural or artificially manipulated.
... [130,135,[144][145][146]. A dehydration of >2% body mass deficit has been shown to impair football-specific performance, including intermittent high-intensity sprinting and dribbling skills [135,[146][147][148] and it is also known that greater levels of dehydration will further degrade aerobic exercise performance [149]. Physiologic factors that contribute to dehydration-mediated aerobic exercise performance decrements include increased body core temperature, increased cardiovascular strain, increased glycogen utilization, altered metabolic function, and altered central nervous system function [150,151]. ...
Article
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Contemporary elite soccer features increased physical demands during match-play, as well as a larger number of matches per season. Now more than ever, aspects related to performance optimization are highly regarded by both players and soccer coaches. Here, nutrition takes a special role as most elite teams try to provide an adequate diet to guarantee maximum performance while ensuring a faster recovery from matches and training exertions. It is currently known that manipulation and periodization of macronutrients, as well as sound hydration practices, have the potential to interfere with training adaptation and recovery. A careful monitoring of micronutrient status is also relevant to prevent undue fatigue and immune impairment secondary to a deficiency status. Furthermore, the sensible use of evidence-based dietary supplements may also play a role in soccer performance optimization. In this sense, several nutritional recommendations have been issued. This detailed and comprehensive review addresses the most relevant and up-to-date nutritional recommendations for elite soccer players, covering from macro and micronutrients to hydration and selected supplements in different contexts (daily requirements, pre, peri and post training/match and competition).
... Water is essential for the optimal physiological function of the human body, because it is a source of minerals and electrolytes and is involved in metabolic processes [1]. Low fluid consumption and inadequate water intake could induce dehydration and its consequences, increase the risk of urolithiasis and non-communicable chronic diseases [2] and have some undesirable effects on cognitive function and physical performance [3]. Consequently, adequate water intake is 1 3 necessary to maintain a good health status. ...
Article
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Purpose We aimed to evaluate associations between compliance with recommendations for total water intake (TWI) and total water intake from fluids (TWIF), and some socio-demographic and lifestyle factors of a senior Mediterranean population at high cardiovascular risk. Methods Cross-sectional analysis with data of 1902 participants from the PREDIMED-Plus study. A validated 32-item Spanish fluid-intake questionnaire was used to assess beverage consumption and water intake. Multivariable logistic regression models were used to assess the odds ratio (OR) and the 95% confidence interval (CI) for complying with European Food Safety Agency recommendations for TWI and TWIF according to various socio-demographic and lifestyle factors, and for the joint associations of Mediterranean diet (MedDiet) adherence and moderate–vigorous physical activity (MVPA). Results The mean total volume of fluid intake in the population studied was 1934 ± 617 mL/day. Water was the most frequently consumed beverage. Significant differences between sex were only observed in alcoholic and hot beverage consumption. Compliance with TWIF was associated with being women (OR 3.02; 2.40, 3.80), high adherence to MedDiet (OR 1.07; 1.02, 1.12), and participants who were more engaged in physical activity (PA) (OR 1.07; 1.02, 1.13). Age was inversely associated (OR 0.96; 0.94, 0.98). Similar results for TWI recommendations compliance were observed in relation to being women (OR 5.34; 3.85, 7.42), adherence to MedDiet (OR 1.16; 1.02, 1.31) and PA (OR 1.07; 1.00, 1.15). The joint association of PA and MedDiet, showed that participants with higher adherence to MedDiet and meeting WHO recommendations for MVPA complied better with the TWI recommendations (OR 1.66; 1.19, 2.32). Conclusions High compliance with recommendations for TWI was associated with being a woman, and a healthy lifestyle characterized by high adherence to the MedDiet and PA.
Article
Background: Most studies that involve Black Seventh-Day Adventists (SDAs) have been conducted in the United States. We sought to examine the association between religious involvement and lifestyle practices among Black SDAs in Canada. Method: A convenience sample of 509 Black SDA church members 18 years and older completed a self-administered questionnaire, assessing religious involvement and seven lifestyle practices promoted by the SDA church: diet, physical activity, water intake, exposure to sunlight, alcohol use, caffeine and tobacco use, and rest. Results: Compliance with lifestyle practices ranged from a low of 10% meeting fitness guidelines to a high of 99% abstaining from tobacco products. Religious involvement and lifestyle were positively related (rs = .11, p < .05). Multivariate analyses indicated that private religious practice (β = .16, p =.003), importance of the health principles (β = .17, p = .003), and acceptance of health principles (β = .65, p = .00001) significantly predicted the number of behaviors practiced. Conclusion: Greater religious involvement is associated with positive lifestyle practices but is not an independent predictor of lifestyle practices for Black Canadian SDAs.
Article
Background: Dehydration appears to affect muscle strength and weakness, although its influence on exhaustion remains unclear. The present study aimed to quantify the association between hydration status and exhaustion among older adults. Methods: A cluster sampling approach was used, representing Portuguese older adults (≥65 years) according to age, sex, education level and region within the Nutrition UP65 cross-sectional study. A 24-h urine sample was collected to estimate free water reserve (FWR), which was categorised into tertiles according to sex. Subjects with incomplete 24-h urine and renal disease were excluded. From a sample size of 1500 subjects, 1143 were eligible. Exhaustion was self-reported according to the Center for Epidemiologic Studies Depression Scale. A logistic regression model was conducted to evaluate the association between FWR and exhaustion. Odds ratios and the respective 95% confidence intervals were calculated by sex and age. Results: Free water reserve median (interquartile range) was 0.52 (0.68) L in women and 0.36 (0.77) L in men. Hypohydration affected 11.6% of women and 25.1% of men, whereas exhaustion was reported by 39.3% of women and 25.1% of men. After adjusting for confounders, women ≥80 years classified in the highest tertile of FWR showed a decreased risk of exhaustion (third tertile: odds ratio = 0.38; 95% confidence interval = 0.15-0.96) compared to women in the lowest FWR tertile. No such significant association was observed in women with <80 years and in men. Conclusions: These results show an association between worse hydration status and exhaustion in older women, highlighting the need to implement further studies clarifying this association.
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líquidos por mujeres mexicanas durante el embarazo y primer semestre de lactancia. 135 Introducción Existen diversos mecanismos que ayudan a controlar y regular el estado de hidratación, de manera que la osmolalidad del plasma se mantenga entre 285 y 295 mOsm/kg. De manera resumida, estos mecanismos incluyen señales fisiológicas para motivar la ingesta (la sensación de sed) y diversos mecanismos para limitar la pérdida de líquidos, que incluyen la reducción en el volumen urinario, así como la elevación en la concentración de la orina (Armstrong et al. 2010, Kavouras 2013). Una disminución de 1-3% en la osmolalidad del plasma dispara los primeros síntomas y signos de deshidratación, consistentes en incremento en la sed y aumento en la concentración urinaria (Phillips et al. 1985). La mayor parte del agua que se encuentra en el organismo proviene de la ingesta oral, ya sea mediante bebidas (75-80% del aporte dia-rio, aproximadamente 2100 mL/día) o como parte de los alimentos (20-25% del aporte diario, aproximadamente 700 mL/día), aunque hay también una pequeña proporción (~1%) que proviene del meta-bolismo celular (la oxidación de las grasas y almidones produce Consumo de líquidos por mujeres mexicanas durante el embarazo y primer semestre de lactancia.
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Both acute and chronic dehydration can have important implications for human behaviour and health. Young children, non-autonomous individuals and the elderly are at a greater risk of dehydration. Mild hypertonic dehydration could be related to less efficient cognitive and physical performance and has been reported to be associated with frequently occurring pathological conditions, especially nephrolithiasis. The assessment of hydration status in a large sample appears to be of interest for conducting epidemiological and large clinical studies aimed at improving preventive and curative care. Especially in large-population studies, methods that are used have to be accurate, cheap, quick and require no technical expertise. Body weight change is widely used to determine acute hydration changes, but seems to be insufficiently accurate in longitudinal studies. Bioimpedance analysis methods enable the assessment of total body water content, but their use is still under debate. Because plasma osmolality directly reflects intracellular osmolality, it constitutes a good marker to assess acute hydration changes, but not chronic hydration status because it changes constantly. Moreover, venepuncture is considered to be invasive and is not suitable for a large-sample study, especially in children. Urinary markers appear to be good alternatives for assessing hydration status in large populations. Collection of urine samples is non-invasive and cheap. High technical expertise is not required to perform urinary marker measurements and these measurements can be carried out quickly. Thus, methods based on urinary markers are very well suited for field studies. Urine colour is probably the least sensitive marker despite its high specificity. Urine osmolality and especially urine specific gravity could be easily used for determining hydration status in large-sample studies.
Chapter
Water plays an important role in the body. Normal–weight adults need 2.0–2.5 L/day of water for proper hydration, and it is known for centuries that minerals from the water are important for humans and animals. Different minerals are important in different ranges for different organs and functions. Due to the mass–related need for the minerals, they are labeled macro and micro elements, respectively. Weathering of rocks is responsible for most of the minerals appearing in water. The importance of minerals from drinking water have been denied for some time. However, in districts of Norway, high frequencies of softening of bone tissue among domestic animals, later identified as phosphorous-deficient soils and water, was known hundreds of years ago, and parts of China had increased levels of heart failure, nowadays identified as low selenium. In the nineteenth and twentieth centuries, well–off people in Europe went to health resorts to drink their specific water, water chosen with mineral content expected to be good for a specific complaint.
Thesis
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Bu çalışmanın amacı, elit güreşçilerde dehidrasyonun akut iskelet kası hasarı ve inflamasyon düzeyleri üzerine etkisini incelemektir. Araştırmaya Türkiye şampiyonasına katılan 72 gönüllü erkek elit güreşçi katılmıştır. Bir şampiyona öncesi sıkletlerinde yarışabilmek için ağırlık kaybı gerçekleştiren ve ağırlık kaybı gerçekleştirmeyen güreşçiler rastgele yöntem ile çalışmaya dahil edilmiş ve çalışmaya katılan güreşçilerdan müsabaka tartısının yapılacağı saatte demografik bilgileri içeren bilgi formu ve ön kol venözlerinden 5 cc’lik kanlar vacutainer (kapalı kan alma sistemi) ile alınmıştır. Alınan kan örnekleri Nüve marka NF-400 model santrifüj cihazı kullanılarak 5 dk. 4000 devirde santrifüj edilerek serumları ayrıldı. Ayrılan serum örneklerinde dehidrasyonun tespiti için Sodyum (Na+), Kan Üre Azotu (BUN) ve Glukoz seviyeleri analiz edilerek Plazma Ozmolarite (POsm) düzeyleri hesaplanmıştır. POsm değerleri ≤290 olan güreşçiler dehidrasyon olmayan grup, >290 olan güreşçiler ise dehidrasyon grubu olarak ele alınmıştır. Yine güreşçilerdeki iskelet kası hasarını belirleyebilmek için Kreatin Kinaz (CK), Laktat Dehidrogenaz (LDH), Aspartat Aminotransferaz (AST) ve Alanin Aminotransferaz (ALT) değerleri Beckman Coulter marka AU2700 Plus model biyokimya otoanalizöründe Beckman Coulter marka kitler kullanılarak ve İnflamasyonun belirlenebilmesi için C-RP düzeyleri ise Beckman Coulter marka İmage 800 model nefolometre otoanalizöründe Beckman Coulter marka kit kullanılarak sonuçlar elde edilmiştir. Elde edilen verilerin normallik sınaması Shapiro Wilk testi ile yapılmış ve normal dağılım gösteren değişkenler arasındaki ilişkiler korelasyon analizi ile incelenmiş olup, değişkenlerin karşılaştırılmasında iki grup için; Bağımsız Örneklem T Testi (Independent Samples T Test), ikiden fazla grup için; Tek Yönlü Varyans Analizi (One Way ANOVA) kullanıldı. Ayrıca yapılan varyans analizi sonucunda elde edilen farkların hangi ölçüm sonuçlarından kaynaklandığının tespiti için çoklu karşılaştırma testlerinden LSD testi kullanılmıştır. POsm düzeylerine göre ikiye ayrılan çalışma grubunun hidrasyon belirteçlerinden Na+, BUN, Ağırlık Kaybı ve Ağırlık Yüzde Kaybı değerleri arasında istatistiksel açıdan anlamlı farklılık tespit edilirken (p<0,05), glukoz değerleri arasında istatistiksel açıdan anlamlı farklılık olmadığı tespit edilmiştir (p>0,05). POsm seviyelerine göre iskelet kası hasar belirteçleri incelendiğinde ise AST, LDH, CK değerleri arasında istatistiksel açıdan anlamlı farklılık tespit edilirken (p<0,05), ALT değerleri arasında istatistiksel açıdan anlamlı farklılık olmadığı tespit edilmiştir (p>0,05). Yine inflamasyon düzeyleri karşılaştırıldığında ise C-RP değerleri arasında istatistiksel açıdan anlamlı farklılık olmadığı tespit edilmiştir (p>0,05). Sonuç olarak; Müsabaka öncesi vücutlarını besin ve sıvı kısıtlaması, naylon veya kauçuk elbiseler giyerek, saunalar ya da egzersizler ile ağırlık kaybı gerçekleştirerek dehidrate olan güreşçilerde, dehidrate olmayan güreşçilere nazaran daha fazla iskelet kası hasarı oluştuğu, buna rağmen inflamasyon düzeylerinde ise istatistiksel açıdan anlamlı bir farklılık olmadığı tespit edilmiştir.
Article
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Purpose: The purpose of this study was to investigate the impact of weight loss practices on nutritional status, bone health, and injury history among Korean professional jockeys. Methods: Forty-three male jockeys completed a questionnaire to assess their weight loss practices. Of these, 10 jockeys were selected for in-depth assessment of their nutritional status, bone health, and injury history. Results: The questionnaires revealed that 81.4% of jockeys lost weight every week mainly by dieting and/or exercising. None of the jockeys consumed enough food during the weight loss period. Two jockeys were diagnosed with osteopenia and one was diagnosed with osteoporosis. Only history of fracture showed a significant correlation with low bone mineral density. All jockeys had more than one injury experience throughout their career. Fracture was the most common type of injury, occurring during practice and/or competition and caused mainly by difficulties in handling the horses. Conclusion: Professional jockeys in Korea use extreme weight loss methods. Their repeated periods of poor nutritional intake may result in seriously low bone mineral density, which may aggravate injuries sustained during horse races. Implementation of balanced dietary programs and delivery of health education on weight management are urgently required.
Book
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A complete guide (manual) to migraine prevention and treatment without taking any medicines. It is a self-help guide with full explanation about how to successfully abort and prevent all migraines. The book also provides a full explanation of the cause of migraines from a physiological, biological, and genetics perspective. This book is an extended edition of the "Fighting the Migraine Epidemic: How to Treat and Prevent Migraines without Medicines. An Insider's View" book published and now discontinued. The book is laid out in five parts: Part I: migraineurs who read the 1st edition of the book comment and introduction Part II: quick guide to get rid of an ongoing migraine Part III: the heart of the book, describing the physiology and biology or migraines, who is susceptible to migraines and why. Also includes all prodrome types, all triggers, and detailed analysis on how triggers can be cancelled. Part IV: a more complex explanation of migraine-cause specifically for doctors, scientists, and migraineurs more interested in the genetics and bio-physiology of migraines. It also contains a part titled “Drugs of Shame” describing the 30 most often prescribed medicines for migraine pain prevention, their side effects, and FDA warnings. Part V: a huge citation list of over 800 citations of academic literature. Each academic article adds a little bit of information to complete the whole picture of migraines. In this book I pull together information from many fields of science and connect the dots to help the reader to conclude the same thing I did: migraine is preventable and completely treatable without the use of any medicines.
Chapter
Water plays an important role in the body. Normal–weight adults need 2.0–2.5 L/day of water for proper hydration, and it is known for centuries that minerals from the water are important for humans and animals. Different minerals are important in different ranges for different organs and functions. Due to the mass–related need for the minerals, they are labeled macro and micro elements, respectively. Weathering of rocks is responsible for most of the minerals appearing in water. The importance of minerals from drinking water have been denied for some time. However, in districts of Norway, high frequencies of softening of bone tissue among domestic animals, later identified as phosphorous-deficient soils and water, was known hundreds of years ago, and parts of China had increased levels of heart failure, nowadays identified as low selenium. In the nineteenth and twentieth centuries, well–off people in Europe went to health resorts to drink their specific water, water chosen with mineral content expected to be good for a specific complaint.
Conference Paper
Most health measurement equipment at present can only obtain a single type of physiological data from users and are non-continuous static devices, resulting in the inability of users to continuously monitor their physiological conditions throughout the day. This paper presents the design and development of an integrated heart rate (HR), hydration level (HL) and blood glucose concentration (BGC) sensor system within a continuous monitoring wearable watch. The three identified physiological parameters are measured based on a single multi-frequency bio impedance modality in the watch. A parallel signal processing approach is implemented to identify the HR, HL and BGC components from the bio impedance signal and the results are demonstrated in this paper. This highly portable and wearable prototype demonstrates the potential of continuous real-time tracking for health-conscious or diabetic individuals, as well as athletics, who needs to closely monitor their HR, HL and BGC throughout the day.
Conference Paper
Urinary system disorders may be prevented by achieving a good body hydration level (BHL). This paper investigated a measurement platform set-up for detecting the shade of the (yellow) colour of urine and its integration with the IoT principles for providing ubiquitous services to the users (citizens). We propose a smart IoT-based holistic system that consists of a urine colour measurement component to be fitted in urinals. Based on RGB colour theory, the system was implemented using a myRio board, which interacts with a mobile application. Bio-samples (urine) gathered from volunteers were tested using this board and with a hand-held refractometer. The results showed that it is possible to infer the BHL by analysing the blue values of RGB colour and by comparison with the recommended urine colour chart. We believe that the proposed system promotes sustainable healthy lifestyle through its ubiquitous “on-the-go” self-test solution and raises BHL awareness in a “greener” and more “personal” way.
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Background: Nepal is one of the largest suppliers of low skilled laborer to gulf countries. The conditions surrounding the migration can increase health vulnerabilities due to lifestyle pattern. This study assessed the lifestyle pattern adopted by migrant workers in gulf countries and Malaysia.
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The effect of changes in cell volume on the rates of release of glutamine and alanine from muscle and on the concentrations of these amino acids in muscle were investigated by using an isolated preparation of rat skeletal muscle incubated in the presence of hypo- and hyper-osmotic media. Changes in cell volume were associated with changes in the rates of release of glutamine and alanine from muscle: incubation in hypo-osmotic medium decreased the rates of release of glutamine and alanine, and incubation in hyperosmotic medium increased these rates. These changes were rapidly reversed by a change in osmoticity of the medium. Despite marked changes in cell volume, the concentrations of these amino acids in muscle were maintained. It is suggested that cell volume may play a role in the regulation of amino acid metabolism in skeletal muscle.
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A recently published and widely quoted modified food guide pyramid encourages persons over the age of 70 years to ingest eight glasses (2 liters) of fluids per day. We challenge the need for this much fluid intake and even question whether it may do more harm than good. Equal numbers of Hispanic and non-Hispanic white men and women were selected randomly from the Health Care Financing Administration (Medicare) rolls and recruited for a home interview followed by a 4-hour interview/examination in a senior health clinic. Questionnaires and examinations were used to determine usual daily self-reported intake of fluids, lying and standing blood pressures, history of falls over the past year, and the presence of chronic constipation and chronic fatigue or tiredness. Serum samples were obtained for determination of sodium, urea nitrogen (SUN) and creatinine concentrations, and calculation of SUN/creatinine ratios. Interviews/examinations were conducted on 883 volunteers (mean age of 74.1 years). Most participants (71%) estimated that their usual fluid intake was equal to or exceeded six glasses per day. Evidence of hypernatremia (serum sodium concentration > 146 mEq/l) was not observed in the 227 individuals ingesting less than this. Hyponatremia also was rare in this population. Fluid intake showed no significant associations with lying and standing blood pressures, a history of falling, or the frequency of chronic constipation or fatigue/tiredness. Until we have more evidence-based documentation that fluid intake of eight glasses (2 liters) per day improves some aspect of an elderly person's health, encouraging a fluid intake above a level that is comfortable for the individual seems to serve little useful purpose.
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To determine the influence of a diuretic-induced reduction in plasma volume (PV) on substrate turnover and oxidation, 10 healthy young males were studied during 60 min of cycling exercise at 61% peak oxygen uptake on two separate occasions > or =1 wk apart. Exercise was performed under control conditions (CON; placebo), and after 4 days of diuretic administration (DIU; Novotriamazide; 100 mg triamterene and 50 mg hydrochlorothiazide). DIU resulted in a calculated reduction of PV by 14.6 +/- 3.3% (P < 0.05). Rates of glucose appearance (R(a)) and disappearance (R(d)) and glycerol R(a) were determined by using primed constant infusions of [6,6-(2)H]glucose and [(2)H(5)]glycerol, respectively. No differences in oxygen uptake during exercise were observed between trials. Main effects for condition (P < 0.05) were observed for plasma glucose and glycerol, such that the values observed for DIU were higher than for CON. No differences were observed in plasma lactate and serum free fatty acid concentrations either at rest or during exercise. Hypohydration led to lower (P < 0.05) glucose R(a) and R(d) at rest and at 15 and 30 min of exercise, but by 60 min, the effects were reversed (P < 0. 05). Hypohydration had no effect on rates of whole body lipolysis or total carbohydrate or fat oxidation. A main effect for condition (P < 0.05) was observed for plasma glucagon concentrations such that larger values were observed for DIU than for CON. A similar decline in plasma insulin occurred with exercise in both conditions. These results indicate that diuretic-induced reductions in PV decreases glucose kinetics during moderate-intensity dynamic exercise in the absence of changes in total carbohydrate and fat oxidation. The specific effect on glucose kinetics depends on the duration of the exercise.
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Dehydration is a reliable predictor of impaired cognitive status. Objective data, using tests of cortical function, support the deterioration of mental performance in mildly dehydrated younger adults. Dehydration frequently results in delirium as a manifestation of cognitive dysfunction. Although, the occurrence of delirium suggests transient acute global cerebral dysfunction, cognitive impairment may not be completely reversible. Animal studies have identified neuronal mitochondrial damage and glutamate hypertransmission in dehydrated rats. Additional studies have identified an increase in cerebral nicotinamide adenine dinucleotide phosphate-diaphorase activity (nitric oxide synthase, NOS) with dehydration. Available evidence also implicates NOS as a neurotransmitter in long-term potentiation, rendering this a critical enzyme in facilitating learning and memory. With ageing, a reduction of NOS activity has been identified in the cortex and striatum of rats. The reduction of NOs synthase activity that occurs with ageing may blunt the rise that occurs with dehydration, and possibly interfere with memory processing and cognitive function. Dehydration has been shown to be a reliable predictor of increasing frailty, deteriorating mental performance and poor quality of life. Intervention models directed toward improving outcomes in dehydration must incorporate strategies to enhance prompt recognition of cognitive dysfunction.
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There is paramount evidence to suggest the importance of cell volume changes for the regulation of cell function, including protein metabolism. Among many other effects, cell swelling inhibits proteolysis and stimulates protein synthesis. However, most of the data pertinent to this theory relate to in vitro experiments. This paper reviews the evidence about the relevance of cell swelling and changes in water compartments to regulation of metabolism at the whole body level in animals and humans. Protein metabolism is most likely regulated by cellular hydration in health and disease. Cellular hydration appears to bear no effect on energy metabolism. The relationship between cellular hydration and lipolysis deserves to be verified. There appears to be a possible weak effect on glucose metabolism. Further studies are therefore necessary to challenge the cell swelling theory. If confirmed, strategies to modify cellular hydration could be used to improve metabolic orientations especially in the critically ill.
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Hydration status and the effects of hypohydration have been the topic of much public and scientific debate in recent years. While many physiological responses to hypohydration have been studied extensively, the subjective responses to hypohydration have largely been ignored. The present investigation was designed to investigate the physiological responses and subjective feelings resulting from 13, 24 and 37 h of fluid restriction (FR) and to compare these with a euhydration (EU) trial of the same duration in fifteen healthy volunteers. The volunteers were nine men and six women of mean age 30 (sd 12) years and body mass 71.5 (sd 13.4) kg. Urine and blood samples were collected and subjective feelings recorded on a 100 mm verbally anchored questionnaire at intervals throughout the investigation. In the EU trial the subjects maintained their normal diet. Body mass decreased by 2.7 (sd 0.6) % at 37 h in the FR trial and did not change significantly in the EU trial. Food intake in the FR trial (n 10) provided an estimated water intake of 487 (sd 335) ml and urinary losses (n 15) amounted to 1.37 (sd 0.39) litres. This is in comparison with an estimated water intake of 3168 (sd 1167) ml and a urinary loss of 2.76 (sd 1.11) litres in the EU trial. Plasma osmolality and angiotensin II concentrations increased from 0-37 h with FR. Plasma volume decreased linearly throughout the FR trial amounting to a 6.2 (sd 5.1) % reduction by 37 h. Thirst increased from 0-13 h of FR then did not increase further (P>0.05). The subjects reported feelings of headache during the FR trial and also that their ability to concentrate and their alertness were reduced.
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Constipation defined as changes in the frequency, volume, weight, consistency and ease of passage of the stool occurs in any age group. The most important factors known to promote constipation are reduced physical activity and inadequate dietary intake of fibres, carbohydrates and fluids. Fluid losses induced by diarrhoea and febrile illness alter water balance and promote constipation. When children increase their water consumption above their usual intake, no change in stool frequency and consistency was observed. The improvement of constipation by increasing water intake, therefore, may be effective in children only when voluntary fluid consumption is lower-than-normal for the child's age and activity level. In the elderly, low fluid intake, which may be indicative of hypohydration, was a cause of constipation and a significant relationship between liquid deprivation from 2500 to 500 ml per day and constipation was reported. Dehydration is also observed when saline laxatives are used for the treatment of constipation if fluid replacement is not maintained and may affect the efficacy of the treatment. While sulphate in drinking water does not appear to have a significant laxative effect, fluid intake and magnesium sulphate-rich mineral waters were shown to improve constipation in healthy infants. In conclusion, fluid loss and fluid restriction and thus de-or hypohydration increase constipation. It is thus important to maintain euhydration as a prevention of constipation.
Article
Little is known about the relation of hydration status to cognitive performance in older adults, who may be more vulnerable to poor hydration and cognitive impairment. We examined whether hydration status was related to cognitive functioning in 28 healthy community-dwelling older adults. Hierarchical regression models demonstrated that lower hydration status was related to slowed psychomotor processing speed and poorer attention/memory performance, after controlling for demographic variables and blood pressure.
Article
Submitted 8 healthy, endurance trained men (mean age 27.4 yrs), unacclimated to heat, to variations in body hydration. The Ss were kept euhydrated, dehydrated by controlled passive hyperthermia or exercise on a treadmill up to a weight loss of 2.8%, or hyperhydrated using a solution containing glycerol, with a total ingested volume equal to 21.4 ml/kg of body weight. On completion of a 90-min recovery period, the Ss were assigned a pedaling exercise and psychological tests of perceptive discrimination, psycho-motor skill, memory, fatigue and mood, were administered. Both dehydration conditions impaired cognitive abilities without any relative differences between them. Following arm crank exercise, further effects of dehydration were found for tracking performance only. Moreover, long-term memory was impaired in both control and hydration situations, whereas there was no decrement in performance in the hyperhydration condition. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
Article
In this paper, se demonstrated that in cultured rat hepatocytes cell swelling induced the activation of STAT1 and STAT3 proteins without any effect on STAT4, STAT5 and STAT6 proteins, Cell swelling induced an activation of STAT proteins through an increase in the phosphorylation of the tyrosine residue also phosphorylated by interleukin-6, but without any activation of JAK kinases, The signaling pathway by which cell swelling activated STAT1 and STAT3 is discussed. (C) 1999 Federation of European Biochemical Societies.
Article
Variation in mental performance under different levels of heat stress-induced dehydration was recorded in 11 subjects heat acclimatized to the tropicals. Dehydration was induced by a combination of water restriction and exercise in heat. The psychological functions--arithmetic ability, short-term memory, and visuomotor tracking--were assessed in a thermoneutral room after the subjects recovered fully from the effects of exercise in heat, as reflected by their oral temperature and heart rate. The results indicated significant deterioration in mental functions at 2% or more body dehydration levels.
Article
The effect of primary dehydration of various levels (1, 2 and 3% body-weight deficits) on mental functions of different complexities were studied in eight heat-acclimatized subjects drawn from tropical regions of India. These subjects were also studied after a bout of exercise in heat under two conditions viz., Hot Dry (45°C DB, 30% rh), and Hot Humid (39DC DB, 60% rh) at 34°C WBGT. No significant change in routine mental work was seen either under dehydration per se of any level or after subsequent exercise under heat when compared with the normal state. On the other hand, at 2 and 3% levels of primary dehydration a further reduction was noted in all the functions though it was not significant. Inter-variations in Hot Humid and Hot Dry conditions were not significant except for more pronounced reductions in the concentration component in Hot Humid conditions.
Article
Individual total body water volumes for 458 adult males and 265 adult females obtained from dilution studies, together with their height, weight, and age have been selected from the literature. These values were used to derive total body water prediction equations for adults of any age. The equations that gave the best fit were for males: formula (see text) and for females: formula (see text). Numerous other linear regression equations to predict total body water from anthropometric measurements have been reported in the literature. Most apply only to restricted age groups. These, and the equations from the present study were tested on completely independent data. In all cases the equations from the present study gave the best overall results, though for women one equation designed for a specific age group, gave for that age group a marginally better fit.
Article
To review published literature regarding dehydration in older individuals and formulate a consensus on the evaluation and treatment of this unrecognized cause of hospitalizations, morbidity, and mortality. The literature concerning dehydration in the elderly population from MEDLINE was reviewed from 1976 through 1995. Search terms included dehydration, elderly, evaluation, hospitalization, and treatment. Particular emphasis was placed on articles describing original research leading to the development of new information on the evaluation and treatment of dehydration and review articles relating to the epidemiology, detection, treatment and health outcomes of this syndrome common in the geriatric population, including frail, institutionalized individuals. Data contributing to a broad scientific understanding of dehydration were initially grouped according to topic areas of the physiology of normal aging, illness-associated clinical reports of dehydration in the elderly population, and diagnostic and therapeutic interventions. The authors developed a consensus based on the weight of evidence presented and the authors' experience in the field. Early diagnosis is sometimes difficult because the classical physical signs of dehydration may be absent or misleading in an older patient. Many different etiologies place the elderly at particular risk. In patients identified as being at risk for possible dehydration, an interdisciplinary care plan with regard to prevention of clinically significant dehydration is critical if maximum benefit is to result.
Article
Cellular hydration can change within minutes under the influence of hormones, nutrients, and oxidative stress. Such short-term modulation of cell volume within a narrow range acts per se as a potent signal which modifies cellular metabolism and gene expression. It appears that cell swelling and cell shrinkage lead to certain opposite patterns of cellular metabolic function. Apparently, hormones and amino acids can trigger those patterns simply by altering cell volume. Thus alterations of cellular hydration may represent another important mechanism for metabolic control and act as another second or third messenger linking cell function to hormonal and environmental alterations.
Article
There is evidence that cellular hydration state is an important factor controlling cellular protein turnover; protein synthesis and protein degradation are affected in opposite directions by cell swelling and shrinking. An increase in cellular hydration (swelling) acts as an anabolic proliferative signal, whereas cell shrinkage is catabolic and antiproliferative. The cellular hydration state is mainly determined by the activity of ion and substrate transport systems in the plasma membrane. Hormones, substrates, and oxidative stress can change the cellular hydration state within minutes, thereby affecting protein turnover. We postulate that a decrease in cellular hydration in liver and skeletal muscle triggers the protein catabolic states that accompany various diseases.
Article
The aim of this work was a thermodynamic and kinetic study of the influence of varying external osmolarity on overall oxidative phosphorylations in isolated rat liver mitochondria. When external osmolarity is increased from 100 to 400 mosM by using a non-penetrant sugar: (i) matrix volume diminishes, (ii) state 3 respiratory rate decreases when state 4 slightly varies, (iii) states 3 and 4 protonmotive force and NAD(P)H level increase, whereas oxidative phosphorylation efficiency (ATP/O) decreases. Indeed, respiratory flux versus protonmotive force relationships depend on the osmolarity considered: the lower the external osmolarity, the higher the span of overall driving force necessary for the same respiratory rate. To further investigate the mechanism of the decrease in respiratory and ATP synthesis flux leading to a lowering in oxidative phosphorylation efficiency, we determined the adenine nucleotide carrier control coefficient on respiratory and ATP synthesis rates respectively. The main result is that the adenine nucleotide carrier control coefficient on respiratory rate decreases, and conversely that adenine nucleotide carrier control on ATP synthesis rate increases, from iso- to hyperosmolarity. Furthermore, whatever the osmolarity, when state 3 respiratory rate is titrated with carboxyatractyloside, the same relationship is observed between ATP/O ratio and respiratory flux. From many previous studies, it has been shown that an increase in external osmolarity and a consequent decrease in matrix volume inhibits almost all mitochondrial proton pumps (coupling site 1 and 2 of respiratory chain, ATPase) in different ways. In this work, we show that in phosphorylating mitochondria, the adenine nucleotide carrier plays a key role: its inhibition as the external osmolarity increases lowers the state 3 respiration close to state 4 level and consequently leads to a decrease in oxidative phosphorylation efficiency.
Article
To survive, cells have to avoid excessive alterations of cell volume that jeopardize structural integrity and constancy of intracellular milieu. The function of cellular proteins seems specifically sensitive to dilution and concentration, determining the extent of macromolecular crowding. Even at constant extracellular osmolarity, volume constancy of any mammalian cell is permanently challenged by transport of osmotically active substances across the cell membrane and formation or disappearance of cellular osmolarity by metabolism. Thus cell volume constancy requires the continued operation of cell volume regulatory mechanisms, including ion transport across the cell membrane as well as accumulation or disposal of organic osmolytes and metabolites. The various cell volume regulatory mechanisms are triggered by a multitude of intracellular signaling events including alterations of cell membrane potential and of intracellular ion composition, various second messenger cascades, phosphorylation of diverse target proteins, and altered gene expression. Hormones and mediators have been shown to exploit the volume regulatory machinery to exert their effects. Thus cell volume may be considered a second message in the transmission of hormonal signals. Accordingly, alterations of cell volume and volume regulatory mechanisms participate in a wide variety of cellular functions including epithelial transport, metabolism, excitation, hormone release, migration, cell proliferation, and cell death.
Article
Increasing the amount and type of fluid intake in children with simple constipation remains a common intervention recommended by both the medical profession and lay consumers. Efforts to increase overall water intake and/or high osmolarity liquid intake have no research or physiological basis that would result in softer and/or more frequent stools. The purpose of this project was to identify whether an effect on stooling characteristics would be noted with a concerted effort to increase liquid intake.
Article
Constipation is a common complaint among geriatric patients and may result in significant morbidity, especially among nursing home residents. The prevalence of constipation increases with advancing age and may be a result of the aging process, but the exact cause is unknown. The aim of this study was to describe the prevalence of constipation and to determine risk factors for the development of constipation in a large population of nursing home residents. The Minimum Data Set is an assessment instrument used in nearly all Medicare-certified and Medicaid-certified nursing facilities. Nursing home residents who were at least 65 years of age and who had assessments at baseline and at three months were included in the study (N = 21,012). Baseline risk factors were included in a multivariate logistic regression to determine their association with the development of constipation. To allow causal implications, nursing home residents with constipation at baseline were excluded. The variables examined included medications, mobility, comorbid illness, and nutrition. The mean age (+/- standard deviation) of nursing home residents was 83 +/- 8 years, and the population was 70 percent female and 83 percent white. At baseline, the prevalence of constipation was 12.5 percent (N = 2,627). By the three-month assessment, 7 percent (N = 1,291) of nursing home residents had developed constipation. The factors associated independently with the development of constipation were, in order of magnitude, race, decreased fluid intake, pneumonia, Parkinson's disease, and the presence of allergies. Congestive heart failure and the use of a feeding tube were two factors identified as having a protective effect. The variables associated with the development of constipation may be used to identify geriatric nursing home residents at risk and to prevent constipation and its potential complications. Further study is needed to demonstrate a causal relationship between the risk factors and the development of constipation.
Article
This study investigated the effects of heat exposure, exercise-induced dehydration and fluid ingestion on cognitive performance. Seven healthy men, unacclimatized to heat, were kept euhydrated or were dehydrated by controlled passive exposure to heat (H, two sessions) or by treadmill exercise (E, two sessions) up to a weight loss of 2.8%. On completion of a 1-h recovery period, the subjects drank a solution containing 50 g l(-1) glucose and 1.34 g l(-1) NaCl in a volume of water corresponding to 100% of his body weight loss induced by dehydration. (H1 and E1) or levels of fluid deficit were maintained (H0, E0). In the E0, H0 and control conditions, the subject drank a solution containing the same quantity of glucose diluted in 100 ml of water. Psychological tests were administered 30 min after the dehydration phase and 2 h after fluid ingestion. Both dehydration conditions impaired cognitive abilities (i.e. perceptive discrimination, short-term memory), as well as subjective estimates of fatigue, without any relevant differences between the methods. By 3.5 h after fluid deficit, dehydration (H0 and E0) no longer had any adverse effect, although the subjects felt increasingly tired. Thus, there was no beneficial effect of fluid ingestion (H1 and E1) on the cognitive variables. However, long-term memory retrieval was impaired in both control and dehydration situations, whereas there was no decrement in performance in the fluid ingestion condition (H1, E1).
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Chronic mild dehydration is a common condition in some population groups, including especially the elderly and those who participate in physical activity in warm environments. Hypohydration is recognised as a precipitating factor in a number of acute medical conditions in the elderly, and there may be an association, although not necessarily a causal one, between a low habitual fluid intake and some cancers, cardiovascular disease and diabetes. There is some evidence of impairments of cognitive function at moderate levels of hypohydration, but even short periods of fluid restriction, leading to a loss of body mass of 1-2%, lead to reductions in the subjective perception of alertness and ability to concentrate and to increases in self-reported tiredness and headache. In exercise lasting more than a few minutes, hypohydration clearly impairs performance capacity, but muscle strength appears to be relatively unaffected.
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Little is known about the relation of hydration status to cognitive performance in older adults, who may be more vulnerable to poor hydration and cognitive impairment. We examined whether hydration status was related to cognitive functioning in 28 healthy community-dwelling older adults. Hierarchical regression models demonstrated that lower hydration status was related to slowed psychomotor processing speed and poorer attention/memory performance, after controlling for demographic variables and blood pressure.
Methods of assessing body water and body composition
  • P Ritz
Ritz P. Methods of assessing body water and body composition. In: Arnaud MJ, ed. Hydration Throughout Life. Paris: Libbey Eurotext; 1998:63-76.