Spot Urine Concentrations Should Not Be Used for Hydration Assessment: A Methodology Review

2015 ◽  
Vol 25 (3) ◽  
pp. 293-297 ◽  
Author(s):  
Samuel N. Cheuvront ◽  
Robert W. Kenefick ◽  
Edward J. Zambraski
Keyword(s):  
Fluid Intake ◽  
Time Of Day ◽  
Hydration Status ◽  
Simple Explanation ◽  
Single Spot ◽  
Spot Urine ◽  
Sports Science ◽  
Diet And Exercise ◽  
Urine Concentrations ◽  
Hydration Assessment

A common practice in sports science is to assess hydration status using the concentration of a single spot urine collection taken at any time of day for comparison against concentration (specific gravity, osmolality, color) thresholds established from first morning voids. There is strong evidence that this practice can be confounded by fluid intake, diet, and exercise, among other factors, leading to false positive/negative assessments. Thus, the purpose of this paper is to provide a simple explanation as to why this practice leads to erroneous conclusions and should be curtailed in favor of consensus hydration assessment recommendations.

Hydration Status, Fluid Intake, and Electrolyte Losses in Youth Soccer Players

2012 ◽  
Vol 7 (4) ◽  
pp. 367-374 ◽  
Author(s):  
Craig A. Williams ◽  
Jamie Blackwell
Keyword(s):  
Body Mass ◽  
Fluid Intake ◽  
Freezing Point ◽  
Soccer Players ◽  
Hydration Status ◽  
Sweat Loss ◽  
Large Variability ◽  
Youth Soccer ◽  
Sports Science ◽  
Adequate Hydration

The purpose of the study was to determine the hydration status, fluid intake, and electrolyte losses of 21 male professional youth soccer players (age 17.1 ± 0.7 y) training in a cool environment. Pretraining and posttraining measurements of body mass, urine (freezing-point osmolality method), and sweat concentration (flame-emission spectroscopy) were collected. Fourteen players were found to be hypohydrated before training. The amount of fluid lost due to exercise equated to a 1.7% loss in body mass, which equated to a gross dehydration loss of 0.5%. Overall, the soccer players replaced 46% ± 88% of sweat loss during training, and only 4 remained hypohydrated after training. No significant correlations between sweat loss and sweat concentrations of Na+ (r = –.11, P = .67) or K+ (r = .14, P = .58) were found, but there was a significant correlation with Mg2+ (r = –.58, P < .009). This study found large variability in pretraining hydration status that the players were able to rehydrate during the training sessions. However, given the numbers starting training in a hypohydrated state, adequate hydration status before training should be considered by youth players, coaches, and sports-science support staff.

scholarly journals Effects of the Amount and Frequency of Fluid Intake on Cognitive Performance and Mood among Young Adults in Baoding, Hebei, China: A Randomized Controlled Trial

2020 ◽  
Vol 17 (23) ◽  
pp. 8813
Author(s):  
Hairong He ◽  
Jianfen Zhang ◽  
Na Zhang ◽  
Songming Du ◽  
Shufang Liu ◽  
...  
Keyword(s):  
Randomized Controlled Trial ◽  
Young Adults ◽  
Cognitive Performance ◽  
Fluid Intake ◽  
Controlled Trial ◽  
Urine Osmolality ◽  
Memory Test ◽  
Hydration Status ◽  
Randomized Controlled ◽  
Time Point

Water is a critical nutrient that is important for the maintenance of the physiological function of the human body. This article aimed to investigate the effects of the amount and frequency of fluid intake on cognitive performance and mood. A double-blinded randomized controlled trial was designed and implemented on college students aged 18–23 years in Baoding, China. Participants were randomly assigned into one of three groups: the recommended behavior group (RB group) who drank 200 mL of water every 2 h, the half amount group (HA group) who drank 100 mL of water every 2 h, and the high frequency group (HF group) who drank 110 mL of water every 1 h. The intervention lasted 2 days. Urine osmolality, cognitive performance, and mood of participants in each group were compared using the one-way analysis of variance (ANOVA). A total of 92 participants (46 females, 46 males) completed this study with a completion rate of 95.8%. The urine osmolality of the HA group was higher than that of the RB group and the HF group at two time points (p < 0.05). At time point 1, the scores in the portrait memory test and vigor were statistically different (F = 20.45, p < 0.001; F = 5.46, p = 0.006). It was found that the scores for the portrait memory test in the RB group were lower than those in the HA group and the HF group (p = 0.007; p < 0.001), while the scores of the HF group were higher than those of the HA group (p < 0.001). The scores for vigor in the RB group were significantly higher than those of the HA group (p = 0.006), and they were also significantly higher than those of the HF group (p = 0.004). At time point 2, only the scores for vigor were statistically different (F = 3.80, p = 0.026). It was found that the scores for vigor in the RB group were higher than those in the HA group and HF group (p = 0.018; p = 0.019). Both the amount and frequency of fluid intake may affect urine osmolality and vigor, but these factors have limited impacts on cognitive performance. Rational fluid intake behavior may be beneficial to improve the hydration status and mood of young adults. More research is needed, especially experimental research, to allow causal conclusions to be drawn.

scholarly journals Fluid intake, hydration status and its association with cognitive function among adolescents in Petaling Perdana, Selangor, Malaysia

2020 ◽  
Vol 14 (5) ◽  
pp. 490
Author(s):  
Serene En Hui Tung ◽  
Yi Zhang Ch'ng ◽  
Thaneswary V Karnan ◽  
Pei Nee Chong ◽  
Jamil Osman Zubaidah ◽  
...  
Keyword(s):  
Cognitive Function ◽  
Fluid Intake ◽  
Hydration Status

scholarly journals Kecenderungan dehidrasi pada remaja obesitas

2018 ◽  
Vol 7 (1) ◽  
pp. 43-48
Author(s):  
Deny Yudi Fitranti ◽  
Fillah Fithra Dieny ◽  
Binar Panunggal ◽  
Vintantiana Sukmasari ◽  
Gardinia Nugrahani
Keyword(s):  
Physical Activity ◽  
Risk Factor ◽  
Fluid Intake ◽  
Cross Sectional Study ◽  
Hydration Status ◽  
Obese People ◽  
Chi Square ◽  
Cross Sectional ◽  
Obese Adolescents ◽  
Obese Subjects

Background : The content of water in fat cells in obese people is lower than muscle cells so that obese people are more easily dehydrated.Objective : The purpose of this study is to determine the risk factors of dehydration in adolescents.Methods : This study was a cross sectional study which began with screening of 168 students at SMA N 1 and 2 Semarang and found 63 students fulfilled the inclusion criteria. Subjects were selected by consecutive sampling. The dependent variable of this study is hydration status measured by the urine spesific gravity method. The independent variables consisted of obesity status that determined by the BMI/Age Z-score value, fluid intake was assessed using Semi Quantitative Food Frequency Questionnaire (SQ-FFQ), physical activity was assessed using physical activity questionnaire, whereas knowledge regarding fluid was assessed by questionnaire. Data were analyzed using Chi Square test.Results ; There were 52,4% (n=33) subjects who were obese and only 9,5% (n=6) subjects were well-hydrated. The incidence of dehydration in obese adolescents (63,6%) was higher than non obese adolescents (36,7%). Obese subjects was 1.73 times more dehydrated than non obese subjects. Subject with deficiency of fluid intake was 1,85 times more dehydrated than subject with adequate fluid intake. Knowledge regarding fluid and physical activity was not a risk factor for dehydration in adolescents.Conclusion :Obesity and inadequate fluid intake ia risk factor for dehydration in adolescents

scholarly journals Comparison of single spot urinary albumin-creatinine ratio with 24-hour urinary protein excretion in women with preeclampsia

2018 ◽  
Vol 7 (5) ◽  
pp. 1929
Author(s):  
Indu Kaul ◽  
Bawa Ram Bhagat ◽  
Deepika Sharma ◽  
Gagan Singh
Keyword(s):  
Urine Sample ◽  
Predictive Value ◽  
Solute Concentration ◽  
Urinary Protein Excretion ◽  
Urinary Protein ◽  
Creatinine Ratio ◽  
Albumin Creatinine Ratio ◽  
Single Spot ◽  
Spot Urine ◽  
Protein Excretion

Background: The measurement of albumin: creatinine ratio (ACR) in a spot urine sample avoids the influence of variation in urinary solute concentration and provides a more convenient and rapid method to assess protein excretion. The aim of this study was to evaluate urinary spot ACR as a new marker for proteinuria and to study its correlation and accuracy in comparison with 24-hour urinary protein.Methods: The prospective one-year study was conducted on 100 pregnant women, 18-40 years, >20 weeks gestation with a diagnosis of preeclampsia. A spot midstream urine sample was taken for detection of albuminuria by dipstick method. Another spot sample was taken for detection and calculation of spot ACR. The 24-hour urine collection was taken immediately afterward to evaluate 24-hour urinary protein excretion.Results: A positive linear relation exists between ACR and 24-hour urinary protein excretion The ROC revealed cut-off of 20.4 with 88.5% sensitivity, 75% specificity, 98.8% positive predictive value and 21.4% negative predictive value. Spot urinary ACR >20.4 correctly identified women having 24-hour urinary protein excretion in excess of 0.3 gm/DL.Conclusions: A strong correlation exists between single spot urinary ACR with 24-hour urinary protein excretion in women with preeclampsia.

The Influence of Heat Acclimation and Hypohydration on Post-Weight-Loss Exercise Performance

2020 ◽  
Vol 15 (2) ◽  
pp. 213-221
Author(s):  
Oliver R. Barley ◽  
Dale W. Chapman ◽  
Georgios Mavropalias ◽  
Chris R. Abbiss
Keyword(s):  
Body Mass ◽  
Exercise Performance ◽  
Fluid Intake ◽  
Heat Acclimation ◽  
Hydration Status ◽  
Performance Variables ◽  
Pooled Data ◽  
Ad Libitum ◽  
Experimental Trials ◽  
Food And Fluid Intake

Purpose: To examine the influence of fluid intake on heat acclimation and the subsequent effects on exercise performance following acute hypohydration. Methods: Participants were randomly assigned to 1 of 2 groups, either able to consume water ad libitum (n = 10; age 23 [3] y, height 1.81 [0.09] m, body mass 87 [13] kg; HAW) or not allowed fluid (n = 10; age 26 [5] y, height 1.76 [0.05] m, body mass 79 [10] kg; HANW) throughout 12 × 1.5-h passive heat-acclimation sessions. Experimental trials were completed on 2 occasions before (2 baseline trials) and 1 following the heat-acclimation sessions. These sessions involved 3 h of passive heating (45°C, 38% relative humidity) to induce hypohydration followed by 3 h of ad libitum food and fluid intake after which participants performed a repeat sled-push test to assess physical performance. Urine and blood samples were collected before, immediately, and 3 h following hypohydration to assess hydration status. Mood was also assessed at the same time points. Results: No meaningful differences in physiological or performance variables were observed between HANW and HAW at any time point. Using pooled data, mean sprint speed was significantly (P < .001) faster following heat acclimation (4.6 [0.7] s compared with 5.1 [0.8] s). Furthermore, heat acclimation appeared to improve mood following hypohydration. Conclusions: Results suggest that passive heat-acclimation protocols may be effective at improving short-duration repeat-effort performance following acute hypohydration.

scholarly journals Small Differences in Everyday Hydration Status Influence Mood (P04-134-19)

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
David Benton ◽  
Alecia Cousins ◽  
Hayley Young
Keyword(s):  
Body Mass ◽  
Psychological Functioning ◽  
Fluid Intake ◽  
Urine Osmolality ◽  
Normal Diet ◽  
Hydration Status ◽  
Funding Sources ◽  
Lower Baseline ◽  
Urine Production ◽  
The Impact

Abstract Objectives Reviews consistently find that a loss of about 2% of body mass was needed before either athletic or psychological functioning is disrupted. However, although it is usually assumed that the minor changes in hydration status, that occur during normal life, do not impact on performance, experimentally the topic has been virtually ignored. The impact of everyday variations in hydration was therefore examined. Methods 168 subjects were randomly allocated to drinking water, or not drinking, and in addition consume capsules containing either 300 mg of sodium chloride or a placebo. Subjects were monitored over a three-hour period, during which urine osmolality, loss of body mass and urine production were monitored. Repeatedly subjects reported their mood. Results Subjects came having consumed their normal diet, without any restriction on fluid intake: on average 0.5% body mass was lost during the study. The major finding was that the hydration status on arrival had a greater influence, than subsequent fluid intake and changes in osmolality during the study. With ratings of being agreeable rather than hostile, those with lower baseline osmolality who drank water had better mood than if baseline osmolality was high. As another example, the mood of those who did not drink water only declined during the study when baseline osmolality was high rather than low. With measures of being composed rather than anxious, and being confidence rather than unsure, those who had lower baseline osmolality had a better mood, irrespective of whether water was consumed. Thus, baseline osmolality had an impact greater than drink induced changes in osmolality. Traditionally the normal range of urine osmolality has been said to be 200–800 mOsmoles/kg, yet the critical point at which the response to fluid intake changed was 600 mOsmoles/kg: 61% had a baseline osmolality over 600 and 38% over 800 mOsmoles/kg. Conclusions Some individuals are in a state of dehydration that adversely influences mood; a state not reversed by acute fluid consumption. The pattern of consumption associated with mild-dehydration and its functional consequences needs to be established. Funding Sources There was no funding external other than provided by ** University.

Sweat rate, salt loss, and fluid intake during an intense on-ice practice in elite Canadian male junior hockey players

2008 ◽  
Vol 33 (2) ◽  
pp. 263-271 ◽  
Author(s):  
Matthew S. Palmer ◽  
Lawrence L. Spriet
Keyword(s):  
Mass Loss ◽  
Body Mass ◽  
Fluid Intake ◽  
Sweat Rate ◽  
Sodium Concentration ◽  
Urine Specific Gravity ◽  
Hydration Status ◽  
Body Mass Loss ◽  
Hockey Players ◽  
Sodium Loss

Previous research in many sports suggests that losing ~1%–2% body mass through sweating impairs athletic performance. Elite-level hockey involves high-intensity bursts of skating, arena temperatures are >10 °C, and players wear protective equipment, all of which promote sweating. This study examined the pre-practice hydration, on-ice fluid intake, and sweat and sodium losses of 44 candidates for Canada’s junior men’s hockey team (mean ± SE age, 18.4 ± 0.1 y; height, 184.8 ± 0.9 cm; mass, 89.9 ± 1.1 kg). Players were studied in groups of 10–12 during 4 intense 1 h practices (13.9 °C, 66% relative humidity) on 1 day. Hydration status was estimated by measuring urine specific gravity (USG). Sweat rate was calculated from body mass changes and fluid intake. Sweat sodium concentration ([Na]) was analyzed in forehead sweat patch samples and used with sweat rate to estimate sodium loss. Over 50% of players began practice mildly hypohydrated (USG > 1.020). Sweat rate during practice was 1.8 ± 0.1 L·h–1 and players replaced 58% (1.0 ± 0.1 L·h–1) of the sweat lost. Body mass loss averaged 0.8% ± 0.1%, but 1/3 of players lost more than 1%. Sweat [Na] was 54.2 ± 2.4 mmol·L–1 and sodium loss averaged 2.26 ± 0.17 g during practice. Players drank only water during practice and replaced no sodium. In summary, elite junior hockey players incurred large sweat and sodium losses during an intense practice, but 2/3 of players drank enough to minimize body mass loss. However, 1/3 of players lost more than 1% body mass despite ready access to fluid and numerous drinking opportunities from the coaches.

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