Water Balance and Salt Losses in Competitive Football

2007 ◽  
Vol 17 (6) ◽  
pp. 583-594 ◽  
Author(s):  
Ronald J. Maughan ◽  
Phillip Watson ◽  
Gethin H. Evans ◽  
Nicholas Broad ◽  
Susan M. Shirreffs
Keyword(s):  
Urine Osmolality ◽  
Sodium Concentration ◽  
Individual Variability ◽  
Fluid Replacement ◽  
Hydration Status ◽  
Large Individual ◽  
Cool Environment ◽  
Football Match ◽  
Before And After ◽  
Sweat Sodium

Fluid balance and sweat electrolyte losses were measured in the players and substitutes engaged in an English Premier League Reserve competitive football match played at an ambient temperature of 6–8 °C (relative humidity 50–60%). Intake of water and/or sports drink and urine output were recorded, and sweat composition was estimated from absorbent swabs applied to 4 skin sites for the duration of the game. Body mass was recorded before and after the game. Data were obtained for 22 players (age 21 y, height 180 cm, mass 78 kg) and 9 substitutes (17 y, 181 cm, 72 kg). All were male. Two of the players were dismissed during the game, and none of the substitutes played any part in the game. Mean ± SD sweat loss of players amounted to 1.68 ± 0.40 L, and mean fluid intake was 0.84 ± 0.47 L (n = 20), with no difference between teams. Corresponding values for substitutes, none of whom played in the match, were 0.40 ± 0.24 L and 0.78 ± 0.46 L (n = 9). Prematch urine osmolality was 678 ± 344 mOsm/kg: 11 of the 31 players provided samples with an osmolality of more than 900 mOsm/kg. Sweat sodium concentration was 62 ± 13 mmol/L, and total sweat sodium loss during the game was 2.4 ± 0.8 g. These descriptive data show a large individual variability in hydration status, sweat losses, and drinking behaviors in a competitive football match played in a cool environment, highlighting the need for individualized assessment of hydration status to optimize fluid-replacement strategies.

Hydration Status in Adolescent Judo Athletes Before and After Training in the Heat

2012 ◽  
Vol 7 (1) ◽  
pp. 39-46 ◽  
Author(s):  
Anita M. Rivera-Brown ◽  
Roberto A. De Félix-Dávila
Keyword(s):  
Body Mass ◽  
Training Session ◽  
Well Being ◽  
Sodium Concentration ◽  
High Heat ◽  
The Body ◽  
Hydration Status ◽  
Before And After ◽  
Judo Athletes ◽  
Sweat Sodium

Adolescent judo athletes who train in tropical climates may be in a persistent state of dehydration because they frequently restrict fluids during daily training sessions to maintain or reduce their body weight and are not given enough opportunities to drink.Purpose:Determine the body hydration status of adolescent judo athletes before, immediately after, and 24 h after (24H) a training session and document sweat Na+ loss and symptoms of dehydration.Methods:Body mass and urine color and specific gravity (USG) were measured before, after, and 24 h after a training session in a high-heat-stress environment (29.5 ± 1.0°C; 77.7 ± 6.1% RH) in 24 adolescent athletes. Sweat sodium loss was also determined. A comparison was made between mid-pubertal (MP) and late pubertal (LP) subjects.Results:The majority of the subjects started training with a significant level of dehydration. During the training session, MP subjects lost 1.3 ± 0.8% of their pretraining body mass whereas LP subjects lost 1.9 ± 0.5% (P < .05). Sweat sodium concentration was 44.5 ± 23.3 mmol/L. Fluid intake from a water fountain was minimal. Subjects reported symptoms of dehydration during the session, which in some cases persisted throughout the night and the next day. The 24H USG was 1.028 ± 0.004 and 1.027 ± 0.005 g/mL for MP and LP, respectively.Conclusions:Adolescent judo athletes arrive to practice with a fluid deficit, do not drink enough during training, and experience symptoms of dehydration, which may compromise the quality of training and general well-being.

scholarly journals Hydration Status, Fluid Intake, Sweat Rate, and Sweat Sodium Concentration in Recreational Tropical Native Runners

Nutrients ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 1374
Author(s):  
Juthamard Surapongchai ◽  
Vitoon Saengsirisuwan ◽  
Ian Rollo ◽  
Rebecca K. Randell ◽  
Kanpiraya Nithitsuttibuta ◽  
...  
Keyword(s):  
Fluid Intake ◽  
Sweat Rate ◽  
Statistical Significance ◽  
Sodium Concentration ◽  
Fluid Replacement ◽  
Whole Body ◽  
Hydration Status ◽  
P Value ◽  
Sweat Sodium Concentration ◽  
Sweat Sodium

Aim: The purpose of this study was to evaluate hydration status, fluid intake, sweat rate, and sweat sodium concentration in recreational tropical native runners. Methods: A total of 102 males and 64 females participated in this study. Participants ran at their self-selected pace for 30–100 min. Age, environmental conditions, running profiles, sweat rates, and sweat sodium data were recorded. Differences in age, running duration, distance and pace, and physiological changes between sexes were analysed. A p-value cut-off of 0.05 depicted statistical significance. Results: Males had lower relative fluid intake (6 ± 6 vs. 8 ± 7 mL·kg−1·h−1, p < 0.05) and greater relative fluid balance deficit (−13 ± 8 mL·kg−1·h−1 vs. −8 ± 7 mL·kg−1·h−1, p < 0.05) than females. Males had higher whole-body sweat rates (1.3 ± 0.5 L·h−1 vs. 0.9 ± 0.3 L·h−1, p < 0.05) than females. Mean rates of sweat sodium loss (54 ± 27 vs. 39 ± 22 mmol·h−1) were higher in males than females (p < 0.05). Conclusions: The sweat profile and composition in tropical native runners are similar to reported values in the literature. The current fluid replacement guidelines pertaining to volume and electrolyte replacement are applicable to tropical native runners.

Hydration status and fluid and sodium balance in elite Canadian junior women’s soccer players in a cool environment

2012 ◽  
Vol 37 (5) ◽  
pp. 931-937 ◽  
Author(s):  
Jennifer C. Gibson ◽  
Lynneth A. Stuart-Hill ◽  
Wendy Pethick ◽  
Catherine A. Gaul
Keyword(s):  
Body Mass ◽  
Training Session ◽  
Sodium Concentration ◽  
Female Adolescent ◽  
Sodium Balance ◽  
Hydration Status ◽  
Sweat Loss ◽  
Cool Environment ◽  
Sweat Sodium Concentration ◽  
Sweat Sodium

Dehydration can impair mental and on-field performance in soccer athletes; however, there is little data available from the female adolescent player. There is a lack of research investigating fluid and electrolyte losses in cool temperatures. Therefore, the purpose of this study was to investigate the pretraining hydration status, fluid balance, and sweat sodium loss in 34 female Canadian junior elite soccer athletes (mean age ± SD, 15.7 ± 0.7 years) in a cool environment. Data were collected during two 90 min on-field training sessions (9.8 ± 3.3 °C, 63% ± 12% relative humidity). Prepractice urine specific gravity (USG), sweat loss (pre- and post-training body mass), and sweat sodium concentration (regional sweat patch method) were measured at each session. Paired t tests were used to identify significant differences between training sessions and Pearson’s product moment correlation analysis was used to assess any relationships between selected variables (p ≤ 0.05). We found that 45% of players presented to practice in a hypohydrated state (USG > 1.020). Mean percent body mass loss was 0.84% ± 0.07% and sweat loss was 0.69 ± 0.54 L. Although available during each training session, fluid intake was low (63.6% of players consumed <250 mL). Mean sweat sodium concentration was 48 ± 12 mmol·L–1. Despite low sweat and moderate sodium losses, players did not drink enough to avoid mild fluid and sodium deficits during training. The findings from this study highlights the individual variations that occur in hydration management in athletes and thus the need for personalized hydration guidelines.

The taste of salt in the athlete’s soup: a short update with practical recommendations

2017 ◽  
Vol 65 (1) ◽  
Keyword(s):  
Exercise Performance ◽  
Sodium Intake ◽  
Taste Preference ◽  
Sodium Concentration ◽  
Fluid Replacement ◽  
Hydration Status ◽  
Plasma Volume Expansion ◽  
Increased Risk ◽  
Sodium Ingestion ◽  
The Right

The general recommendation for daily sodium consumption is about 6 g/d, as a higher intake was associated with an increased risk for cardiovascular mortality in individuals already suffering from hypertension. However, this recommendation is not necessarily valid for athletes as they often experience high sweat and sodium losses during exercise. While it is well-known that a balanced hydration status and fluid replacement are important factors to maintain an adequate exercise performance, the importance of salt losses during exercise seems to be often underestimated. This short update will focus on the role and impact of salt or sodium ingestion before, during and after exercise and its implication on performance. Pre-exercise ingestion of highly concentrated sodium solutions (164 mmol/l) induces a plasma volume expansion leading to a performance enhancing effect. Sodium intake during exercise of more than 60 min helps to prevent from or compensate dehydration. Sports drinks ingested during exercise commonly contain a sodium concentration of 30-50 mmol/l, whereas a higher concentration might be advantageous for so called salty sweaters or athletes prone to heat cramps. For a fast rehydration after exercise, drinks with a sodium concentration of around 100 mmol/l were found to be most effective. In any case, taste preference and gastrointestinal discomfort have to be considered individually and the amount of salt or sodium to be ingested in the different exercise settings depends highly on the desired goal. Finally, the timing of salt or sodium intake as well as the right dosage are of high importance to successfully influence exercise performance.

Intra-Individual Variability in Sweating Rate and Sweat Sodium Concentration with Changes in Exercise Intensity

2016 ◽  
Vol 48 ◽  
pp. 171-172
Author(s):  
Ryan P. Nuccio ◽  
Corey T. Ungaro ◽  
Adam J. Reimel ◽  
Kelly A. Barnes ◽  
Bridget C. Sopeňa ◽  
...  
Keyword(s):  
Exercise Intensity ◽  
Sodium Concentration ◽  
Individual Variability ◽  
Sweating Rate ◽  
Sweat Sodium Concentration ◽  
Sweat Sodium

scholarly journals Health, nutrition and hydration status of Indonesian workers: a preliminary study in two different environmental settings

2014 ◽  
Vol 23 (2) ◽  
pp. 112-6 ◽  
Author(s):  
Saptawati Bardosono ◽  
Ermita Ilyas
Keyword(s):  
Health Status ◽  
Fat Body ◽  
Hdl Cholesterol ◽  
Sodium Concentration ◽  
Working Environment ◽  
Hydration Status ◽  
Chi Square ◽  
Cross Sectional ◽  
Cool Environment ◽  
Nutrition And Hydration

Background: Hydration status in the working environment of hot and conveniently cool may influence the health status of workers, including their hydration status. This study aimed to determine the health, nutrition and hydration status of workers in two different working environment, i.e. hot and conveniently cool environment.Methods: A cross-sectional comparative study was done on apparently healthy male subjects, age 25-45 years. Two groups of factory workers consisted of  39 subjects working in environment exposed directly to heat and the other doing administrative work in cool environment. Data on their health status (physical examination), weight, height, waist circumference, fat body composition, laboratory result, were collected. The data was presented as average value and  proportion; statistical analysis with unpaired-t (Mann-Whitney test) and chi-square test was used.Results: Subjects working in a hot environment were more prone to dehydration  in comparison to their counterparts, as was shown by significantly higher values of several hydration status biomarkers: hemoglobin (15.6 vs 14.8 g/dL, p = 0.017), hematocrit (46 vs 44.5%, p = 0.040), blood viscosity (23 vs 12 mEq/L, p < 0.001), and blood sodium concentration (140 vs 138 mEq/L, p < 0.001). In contrast, subjects working in a conveniently cool environment who did more administrative tasks were physically less active, had significantly lower HDL-cholesterol level (43 vs 52.1 mg/dL, p = 0.005), higher body and visceral fat compositions (21.6 vs 17.6%, p = 0.008, and 10 vs 8%, p = 0.015, respectively) compared to their counterparts.Conclusion: Workers in hot and cool working environment are prone to nutrition- and health problems as well as dehydration, suggesting special attention to the provision of timely drinking water, and physical activity during working time.

Variability of Body Mass and Urine Specific Gravity in Elite Male Field Hockey Players During a Pre-Olympic Training Camp

2019 ◽  
Vol 29 (1) ◽  
pp. 46-50 ◽  
Author(s):  
Jason D. Vescovi ◽  
Greig Watson
Keyword(s):  
Specific Gravity ◽  
Body Mass ◽  
Fluid Replacement ◽  
Urine Specific Gravity ◽  
Hydration Status ◽  
Intraindividual Variation ◽  
Male Athletes ◽  
Training Camp ◽  
Hockey Players ◽  
Before And After

This field-based observational study was designed to examine the intraindividual variation of first morning body mass and urine specific gravity (Usg) in male hockey players (n = 22) during a 10-day training camp. It was also designed to evaluate the prevalence and interrelationship of morning hypohydration and postmatch dehydration using Usg and changes in body mass, respectively. Body mass and Usg were measured upon waking; body mass was also measured before and after matches. Individual means, SD, and coefficient of variation (CV) were calculated for morning body mass and Usg using 3, 6, and 8 days. Daily prevalence for euhydration and postmatch dehydration using morning Usg (<1.020) and changes in body mass (>−2%), respectively, were determined. Measurement of morning body mass and Usg for 3 days had low variability (CV < 1%) with no improvement at 6 or 8 days. Between 36% and 73% of players were considered euhydrated based on morning Usg. Postmatch body mass was reduced >1% in 50–85% of players, with up to 40% experiencing changes >−2%. Postmatch changes in body mass were unrelated to Usg the subsequent morning. These outcomes can be helpful in establishing criteria for detecting meaningful changes in morning body mass and Usg in similar settings, helping to monitor hydration status in elite male athletes. Despite ample fluid availability and consumption, many players experienced hypohydration and dehydration during the camp, indicating that careful monitoring and an individual fluid replacement approach are warranted in these environments.

Novel hydration assessment techniques employing thirst and a water intake challenge in healthy men

2014 ◽  
Vol 39 (2) ◽  
pp. 138-144 ◽  
Author(s):  
Lawrence E. Armstrong ◽  
Matthew S. Ganio ◽  
Jennifer F. Klau ◽  
Evan C. Johnson ◽  
Douglas J. Casa ◽  
...  
Keyword(s):  
Body Mass ◽  
Urine Volume ◽  
Urine Osmolality ◽  
Fluid Replacement ◽  
Urine Specific Gravity ◽  
Hydration Status ◽  
Healthy Men ◽  
Hydration State ◽  
Assessment Techniques ◽  
Hydration Assessment

Exploring novel hydration indices is important because no human biomarker has been shown to be incontrovertibly valid in all life situations. The present investigation was designed to identify inexpensive, nontechnical methods to use when self-assessing hydration status. This investigation evaluated the validity and efficacy of 2 novel techniques (i.e., thirst sensation and urine volume) to assess hydration state of 29 active men (mean ± SD; age, 23 ± 4 years; body mass, 76.02 ± 11.94 kg) at rest. Eight combinations of 4 water challenges (4.8, 9.3, 11.0, or 14 mL·kg−1) and 2 hydration states (mildly hypohydrated (HY), –2.0%; euhydrated (EU), –0.2% body mass) were employed. First, thirst was linearly related to body water loss, and ratings of thirst distinguished HY from EU (p < 0.001) subsequent to 19 h of controlled food and fluid intake. Second, measurements of urine volume 60 min after consuming a water bolus (11.0 or 14 mL·kg−1) were strongly and inversely correlated with entering hydration state, assessed by urine specific gravity (r2 = 0.76, p < 0.0001) and urine osmolality (r2 = 0.77, p < 0.0001). We concluded that healthy men can employ simple measurements of morning thirst sensation and urine volume to identify the presence of mild hypohydration and to guide fluid replacement. These 2 techniques are relevant because HY (–2% body mass) is the approximate threshold for the onset of thirst, reduced endurance exercise performance, and decrements of working memory and mood.

scholarly journals Availability of a Flavored Beverage and Impact on Children’s Hydration Status, Sleep, and Mood

Nutrients ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1757
Author(s):  
Michael R. Szymanski ◽  
Gabrielle E. W. Giersch ◽  
Margaret C. Morrissey ◽  
Courteney L. Benjamin ◽  
Yasuki Sekiguchi ◽  
...  
Keyword(s):  
Sleep Quality ◽  
Quality Index ◽  
Pittsburgh Sleep Quality Index ◽  
Intervention Group ◽  
Urine Osmolality ◽  
Urine Specific Gravity ◽  
Hydration Status ◽  
Control Group ◽  
Profile Of Mood States ◽  
Urine Color

Euhydration remains a challenge in children due to lack of access and unpalatability of water and to other reasons. The purpose of this study was to determine if the availability/access to a beverage (Creative Roots®) influences hydration in children and, therefore, sleep quality and mood. Using a crossover investigation, 46 participants were randomly assigned to a control group (CON) or an intervention group and received Creative Roots® (INT) for two-week periods. We recorded daily first morning and afternoon urine color (Ucol), thirst perception, and bodyweight of the two groups. Participants reported to the lab once per week and provided first morning urine samples to assess Ucol, urine specific gravity (USG), and urine osmolality (Uosmo). Participants also completed the questionnaires Profile of Mood States-Adolescents (POMS-a) and Pittsburgh Sleep Quality Index (PSQI). Dependent t-tests were used to assess the effects of the intervention on hydration, mood, and sleep quality. Uosmo was greater and Ucol was darker in the control group (mean ± SD) [Uosmo: INT = 828 ± 177 mOsm·kg−1, CON = 879 ± 184 mOsm·kg−1, (p = 0.037], [Ucol:INT = 5 ± 1, CON = 5 ± 1, p = 0.024]. USG, POMS-a, and PSQI were not significant between the groups. At-home daily afternoon Ucol was darker in the control group [INT = 3 ± 1, CON = 3 ± 1, p = 0.022]. Access to Creative Roots® provides a small, potentially meaningful hydration benefit in children. However, children still demonstrated consistent mild dehydration based on Uosmo, despite consuming the beverage.

scholarly journals Interannual comparison of core taxa and community composition of the blow microbiota from East Australian humpback whales

2019 ◽  
Vol 95 (8) ◽  
Author(s):  
C Vendl ◽  
B C Ferrari ◽  
T Thomas ◽  
E Slavich ◽  
E Zhang ◽  
...  
Keyword(s):  
Multiple Stressors ◽  
Physiological State ◽  
Temporal Stability ◽  
Individual Variability ◽  
Habitat Destruction ◽  
Humpback Whales ◽  
Large Individual ◽  
Rrna Gene ◽  
Alpha And Beta Diversity ◽  
Transient Nature

ABSTRACT Cetacean represent vulnerable species impacted by multiple stressors, including reduction in prey species, habitat destruction, whaling and infectious disease. The composition of blow microbiota has been claimed to provide a promising tool for non-invasive health monitoring aiming to inform conservation management. Still, little is known about the temporal stability and composition of blow microbiota in whales. We used East Australian humpback whales (Megaptera novaeangliae) as a model species and collected blow and control samples in August 2016 and 2017 for an interannual comparison. We analysed the blow by barcode tag sequencing of the bacterial 16S rRNA gene. We found that the microbial communities in 2016 and 2017 were statistically similar regarding alpha and beta diversity but distinct to seawater. Zero-radius operational taxonomic units (zOTUs) shared by both groups accounted for about 50% of all zOTUs present. Still, the large individual variability in the blow microbiota resulted in a small number of core taxa (defined as present in at least 60% of whales). We conclude that the blow microbiota of humpback whales is either generally limited and of transient nature or the reduced airway microbiota is the symptom of a compromised physiological state potentially due to the challenges of the whales‘ annual migration.

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