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.

scholarly journals Amateur and Professional Ice Hockey Player Hydration Status and Urine Specific Gravity Values Before and After Training in Winter Conditions

2014 ◽  
Vol 5 (2) ◽  
pp. 53-61 ◽  
Author(s):  
Lilita Ozoliņa ◽  
Inese Pontaga ◽  
Igors Ķīsis
Keyword(s):  
Body Mass ◽  
The Body ◽  
Ice Hockey ◽  
Urine Specific Gravity ◽  
Hydration Status ◽  
Fluid Loss ◽  
Winter Conditions ◽  
Hockey Players ◽  
Before And After ◽  
The Mean

Abstract The aim of our investigation was to determine and compare the pre- and post- training body hydration status in professional and amateur male ice hockey players consumed the drinks according to their thirst sensation in winter conditions. Materials and methods: 11 amateur and 23 professional ice hockey players participated in the investigation. The players were weighted before and after training using precise scales. The body mass composition of every athlete was determined by the body composition analyzer. Every player collected mid–stream urine specimens before and after the training. Urine specific gravity (USG) was measured by urine refractometer. Results: 56% of the professional ice hockey players and 82% of amateur players were hypohydrated before training according to their USG values ≥ 1.020, 5% of professional players were dehydrated their USG values ≥ 1.030. After the training with duration of 1.5 hours the mean body mass decreased for 0.9±0.5% of pre– training value in amateur players and for 1.6±0.8% in professionals (p=0.005). After the training the professional players’ hydration status worsened: 66% were hypohydrated and 26% dehydrated according to USG, the mean USG after training was significantly higher than before it (p=0.011). USG after training did not change in amateur players: their mean USG values before and after training did not differed significantly (p=0.677). Conclusions: Fluid uptake according to thirst sensation in winter conditions cannot compensate the fluid loss at rest and during training especially in professional ice hockey players. The body mass loss exceeded value critical for performance - 2 % in one third part of professionals. The differences between two groups can be explained by higher intensity of exercises during training, the better physical conditioning and greater sweating rate in professional players in comparison with amateurs, which causes close to twice greater uncompensated fluid loss in professionals than in amateurs.

Urine Specific Gravity as a Practical Marker for Identifying Suboptimal Fluid Intake of Runners ∼12-hr Postexercise

2019 ◽  
Vol 29 (1) ◽  
pp. 32-38
Author(s):  
Eric Kyle O’Neal ◽  
Samantha Louise Johnson ◽  
Brett Alan Davis ◽  
Veronika Pribyslavska ◽  
Mary Caitlin Stevenson-Wilcoxson
Keyword(s):  
Specific Gravity ◽  
Body Mass ◽  
Fluid Intake ◽  
Area Under The Curve ◽  
Fluid Replacement ◽  
Urine Specific Gravity ◽  
Hydration Status ◽  
Accuracy Score ◽  
Characteristic Area ◽  
Almost All

The legitimacy of urine specific gravity (USG) as a stand-alone measure to detect hydration status has recently been challenged. As an alternative to hydration status, the purpose of this study was to determine the diagnostic capability of using the traditional USG marker of >1.020 to detect insufficient recovery fluid consumption with consideration for moderate versus high sweat losses (2.00–2.99 or >3% body mass, respectively). Adequate recovery fluid intake was operationally defined as ≥100% beverage fluid intake plus food water from one or two meals and a snack. Runners (n = 59) provided 132 samples from five previous investigations in which USG was assessed 10–14 hr after 60–90 min runs in temperate-to-hot environments. Samples were collected after a meal (n = 58) and after waking (n = 74). When sweat losses exceeded 3% body mass (n = 60), the relationship between fluid replacement percentage and USG increased from r = −.55 to −.70. Correct diagnostic decision improved from 66.6 to 83.3%, and receiver operating characteristic area under the curve increased the diagnostic accuracy score from 0.76 to approaching excellent (0.86). Artifacts of significant prerun hyperhydration (eight of 15 samples has USG <1.005) may explain false positive diagnoses, while almost all (84%) cases of false positives were found when sweat losses were <3.0% of body mass. Evidence from this study suggests that euhydrated runners experiencing significant sweat losses who fail to reach adequate recovery fluid intake levels can be identified by USG irrespective of acute meal and fluid intake ∼12-hr postrun.

scholarly journals Relationships between heart rate variability and indirect indicators of hydration status in elite male field hockey players

2021 ◽  
pp. 174795412110415
Author(s):  
Jason D Vescovi ◽  
Iva Mandic ◽  
Greig Watson
Keyword(s):  
Heart Rate ◽  
Heart Rate Variability ◽  
Body Mass ◽  
Urine Specific Gravity ◽  
Hydration Status ◽  
Field Hockey ◽  
Male Athletes ◽  
Hockey Players ◽  
Meaningful Relationships ◽  
The Relationship

The aim of this study was to examine the relationship between resting morning heart rate variability (HRV) metrics and indirect markers of hydration status in elite male athletes. Twenty-two field hockey players (age 26.8 ± 3.4 yr; height 178.4 ± 6.3 cm; body mass 76.2 ± 7.4 kg) were monitored over 10-d during a pre-Olympic training camp. Measurement of heart rate variability (HRV) during an orthostatic challenge, urine specific gravity (Usg, first morning void) and body mass were captured on seven of the mornings. Individual generalized linear mixed models evaluated the relationships between supine and standing HRV metrics with Usg and day-to-day change in body mass. No meaningful relationships were identified between supine (estimates −0.002 to 0.001) or standing (−0.002 to 0.003) HRV metrics and Usg as well as between supine (−0.003 to 0.016) or standing (−0.004 to 0.006) HRV metrics and changes in body mass. These outcomes indicate that supine and standing HRV metrics are not influenced by indirect indices of hydration status in elite male field hockey players.

Hydration status of Greco-Roman wrestlers in an authentic precompetition situation

2013 ◽  
Vol 38 (6) ◽  
pp. 621-625 ◽  
Author(s):  
Vahur Ööpik ◽  
Saima Timpmann ◽  
Andres Burk ◽  
Innar Hannus
Keyword(s):  
Specific Gravity ◽  
Body Mass ◽  
Urine Osmolality ◽  
Mass Gain ◽  
The Body ◽  
Urine Specific Gravity ◽  
Hydration Status ◽  
Greco Roman ◽  
Reduced Body ◽  
Body Mass Gain

We assessed the urinary indexes of hydration status of Greco-Roman wrestlers in an authentic precompetition situation at the time of official weigh-in (OWI). A total of 51 of 89 wrestlers competing in the Estonian Championship in 2009 donated a urine sample. Questionnaire responses revealed that 27 wrestlers (body mass losers (BMLs)) reduced body mass before the competition, whereas 24 wrestlers (those who do not lose body mass (n-BMLs)) did not. In 42 wrestlers, values of urine specific gravity ≥1.020 and urine osmolality ≥700 mOsmol·kg−1 revealed a hypohydrated status. The prevalence of hypohydration in the BMLs (96%) was higher than in the n-BMLs (67%) (χ2 = 7.68; p < 0.05). The prevalence of serious hypohydration (urine specific gravity >1.030) was 5.3 times greater (χ2 = 8.32; p < 0.05) in the BMLs than in the n-BMLs. In the BMLs, the extent of body mass gain during the 16-h recovery (2.5 ± 1.2 kg) was associated (r = 0.764; p < 0.05) with self-reported precompetition body mass loss (4.3 ± 2.0 kg) and exceeded the body mass gain observed in the n-BMLs (0.7 ± 1.2 kg; p < 0.05). We conclude that hypohydration is prevalent among Greco-Roman wrestlers at the time of OWI. The prevalence of hypohydration and serious hypohydration is especially high among wrestlers who are accustomed to reducing body mass before competition. These results suggest that an effective rehydration strategy is needed for Olympic-style wrestlers, and that changes in wrestling rules should be considered to reduce the prevalence of harmful body mass management behaviours.

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.

Urine specific gravity in exercisers prior to physical training

2006 ◽  
Vol 31 (3) ◽  
pp. 320-327 ◽  
Author(s):  
Elizabeth A Stover ◽  
Heather J Petrie ◽  
Dennis Passe ◽  
Craig A Horswill ◽  
Bob Murray ◽  
...  
Keyword(s):  
Los Angeles ◽  
Specific Gravity ◽  
Geographic Location ◽  
The United States ◽  
Time Of Day ◽  
Fluid Replacement ◽  
Urine Specific Gravity ◽  
Hydration Status ◽  
The Mean ◽  
And Gender

Urine specific gravity (USG) is used as an index of hydration status. Many studies have used USG to estimate pre-exercise hydration in athletes. However, very little is known about the pre-exercise hydration status of recreational exercisers. The purpose of the present study was to measure the pre-exercise USG in a large sample of recreational exercisers who attended 2 different fitness centers in the United States. In addition, we wanted to determine if factors such as time of day, geographic location, and gender influenced USG. We tested 166 subjects in Chicago and 163 subjects in Los Angeles. Subjects completed a survey on their typical training regimen and fluid-replacement habits, and thereafter voided and delivered a urine sample to the investigators prior to beginning exercise. Samples were measured on site for USG using a hand-held refractometer. The mean (SD) USG was 1.018 (± 0.007) for all subjects. Males had a higher average USG (1.020 ± 0.007) when compared with females (1.017 ± 0.008; p = 0.001). Despite differences in climate, no difference in mean USG occurred based on location or time of day. Based on standards used for athletes (USG >= 1.020), 46% of the exercisers were likely to be dehydrated.Key words: dehydration, exercise, hydration.

scholarly journals The psychophysiological effects of a three day dry fast: A self-experimentation case study

2020 ◽  
Author(s):  
Harriet Carroll
Keyword(s):  
Blood Pressure ◽  
Blood Glucose ◽  
Specific Gravity ◽  
Sleep Quality ◽  
Body Mass ◽  
Urine Volume ◽  
Urine Specific Gravity ◽  
Hydration Status ◽  
Fluid Restriction ◽  
Urine Colour

Background: A commonly held belief is that humans cannot survive more than a few days without fluid intake. The source of this is unclear, but does not accord with the few controlled studies that have been conducted to investigate the effects of fluid abstention, nor the few extreme cases of fluid restriction. Methods: This was a self-experimentation, with one day pre-load of fluid and salt (DAY 0), three days complete fluid abstention (&lt; 45 g/d water from food only) (DAYS 1-3), and 24 h rehydration (DAY 4). Days ran from 1500 h to 1500 h. The following measures were taken across various time points across each day: body mass; urine volume; urine colour; urine specific gravity; finger-prick blood glucose concentration; blood pressure; pulse; body temperature; dietary intake; and visual analogue scales (VAS) of food-appetites (satiety and desires), thirst-appetites, mood, wakefulness, and sleep quality. Results: By the end of DAY 3, body water (excluding estimated lean/adipose loss from negative energy balance) decreased by ~1.8 % from 1500 h on DAY 0, or ~4.0 % from 1500 h on DAY 1 (after a fluid preload). With this reduction in body mass came expected reductions in urine volume and increased in urine colour, though trends in urine specific gravity were less pronounced. Blood pressure trended towards being lower during DAYS 1-3 and increased during DAY 4. Whole blood glucose concentrations also tended towards being lower during DAYS 1-3 compared to DAY 4, particularly postprandially. Hunger tended to be reduced during DAYS 1-3, but increased again during DAY 4. Wanting to eat appeared to be a separate construct to hunger/fullness. True-thirst was higher during DAYS 1-3 relative to DAY 4, and this synchronised well with true-xerostomia and ratings of dryness of lips. However, sensational-xerostomia was the dominant thirst experienced during DAY 1-3. Sadness was moderately inversely correlated with body mass loss (r = 0.57) and tiredness was strongly positively correlated (r = 0.94). Sleep quality was unrelated to hydration status. Conclusion: Overall, the expected changes occurred in terms of hydration physiology, but with some unexpected findings in terms of gluco-regulation, blood pressure, and thirst appetites.

scholarly journals Hydration Status in Adolescent Alpine Skiers During a Training Camp

2021 ◽  
Vol 79 (1) ◽  
pp. 55-63
Author(s):  
Dirk Aerenhouts ◽  
Laurent Chapelle ◽  
Peter Clarys ◽  
Evert Zinzen
Keyword(s):  
Specific Gravity ◽  
Fluid Intake ◽  
Training Session ◽  
Urine Specific Gravity ◽  
Hydration Status ◽  
Fluid Loss ◽  
Individual Values ◽  
Training Camp ◽  
Ad Libitum ◽  
Alpine Skiers

Abstract Maintaining euhydration is important for optimal health, performance and recovery, but can be challenging for alpine skiers when training in a relatively cold but dry environment. This study aimed to evaluate hydration status, fluid loss and fluid intake in adolescent alpine skiers during a training camp. Twelve athletes aged 14.3 ± 0.9 years volunteered to participate in the study. Athletes resided at an altitude of 1600 m and trained between 1614 and 2164 m. During eight consecutive days, urine specific gravity was measured before each morning training session using a refractometer. Changes in body weight representing fluid loss and ad libitum fluid intake during each morning training session were assessed using a precision scale. Mean pre-training urine specific gravity remained stable throughout the training camp. Individual values ranged between 1.010 and 1.028 g/cm3with 50 to 83% of athletes in a hypohydrated state (urine specific gravity ≥ 1.020 g/cm3). Mean training induced fluid loss remained stable throughout the training camp (range -420 to -587 g) with individual losses up to 1197 g (-3.5%). Fluid intake was significantly lower than fluid loss during each training session. To conclude, urine specific gravity values before training indicated insufficient daily fluid intake in more than half of the athletes. Furthermore, fluid intake during training in adolescent alpine skiers was suboptimal even when drinks were provided ad libitum. Coaches and athletes should be encouraged to carefully monitor hydration status and to ensure that alpine skiers drink sufficiently during and in between training sessions.

Carbohydrate exerts a mild influence on fluid retention following exercise-induced dehydration

2010 ◽  
Vol 108 (2) ◽  
pp. 245-250 ◽  
Author(s):  
Kristin L. Osterberg ◽  
Shannon E. Pallardy ◽  
Richard J. Johnson ◽  
Craig A. Horswill
Keyword(s):  
Body Mass ◽  
Urine Volume ◽  
Fluid Retention ◽  
Urine Specific Gravity ◽  
Hydration Status ◽  
Excessive Sweating ◽  
Rehydration Solutions ◽  
Before And After ◽  
Postexercise Recovery ◽  
Exercise Induced

Rapid and complete rehydration, or restoration of fluid spaces, is important when acute illness or excessive sweating has compromised hydration status. Many studies have investigated the effects of graded concentrations of sodium and other electrolytes in rehydration solutions; however, no study to date has determined the effect of carbohydrate on fluid retention when electrolyte concentrations are held constant. The purpose of this study was to determine the effect of graded levels of carbohydrate on fluid retention following exercise-induced dehydration. Fifteen heat-acclimatized men exercised in the heat for 90 min with no fluid to induce 2–3% dehydration. After a 30-min equilibration period, they received, over the course of 60 min, one of five test beverages equal to 100% of the acute change in body mass. The experimental beverages consisted of a flavored placebo with no electrolytes (P), placebo with electrolytes (P + E), 3%, 6%, and 12% carbohydrate solutions with electrolytes. All beverages contained the same type and concentration of electrolytes (18 meq/l Na+, 3 meq/l K+, 11 meq/l Cl−). Subjects voided their bladders at 60, 90, 120, 180, and 240 min, and urine specific gravity and urine volume were measured. Blood samples were taken before exercise and 30, 90, 180, and 240 min following exercise and were analyzed for glucose, sodium, hemoglobin, hematocrit, renin, aldosterone, and osmolality. Body mass was measured before and after exercise and a final body mass was taken at 240 min. There were no differences in percent dehydration, sweat loss, or fluid intake between trials. Fluid retention was significantly greater for all carbohydrate beverages compared with P (66.3 ± 14.4%). P + E (71.8 ± 9.9%) was not different from water, 3% (75.4 ± 7.8%) or 6% (75.4 ± 16.4%) but was significantly less than 12% (82.4 ± 9.2%) retention of the ingested fluid. No difference was found between the carbohydrate beverages. Carbohydrate at the levels measured exerts a mild influence on fluid retention in postexercise recovery.

Relationships Between WUT (Body Weight, Urine Color, and Thirst Level) Criteria and Urine Indices of Hydration Status

2021 ◽  
pp. 194173812110384
Author(s):  
Yasuki Sekiguchi ◽  
Courteney L. Benjamin ◽  
Cody R. Butler ◽  
Margaret C. Morrissey ◽  
Erica M. Filep ◽  
...  
Keyword(s):  
Specific Gravity ◽  
Mass Loss ◽  
Body Mass ◽  
Urine Osmolality ◽  
Urine Specific Gravity ◽  
Venn Diagram ◽  
Hydration Status ◽  
Body Mass Loss ◽  
Living Situation ◽  
Urine Color

Background: A Venn diagram consisting of percentage body mass loss, urine color, and thirst perception (weight, urine, thirst [WUT]) has been suggested as a practical method to assess hydration status. However, no study to date has examined relationships between WUT and urine hydration indices. Thus, the purpose of this study was to investigate relationships between urine specific gravity, urine osmolality, and the WUT criteria. Hypothesis: Urine specific gravity and urine osmolality indicate hypohydration when the WUT criteria demonstrate hypohydration (≥2 markers). Study Design: Laboratory cohort study. Level of Evidence: Level 3. Methods: A total of 22 women (mean ± SD; age, 20 ± 1 years; mass, 65.4 ± 12.6 kg) and 21 men (age, 21 ± 1 years; body mass, 78.7 ± 14.6 kg) participated in this study. First morning body mass, urine color, urine specific gravity, urine osmolality, and thirst level were collected for 10 consecutive days in a free-living situation. Body mass loss >1%, urine color >5, and thirst level ≥5 were used as the dehydration thresholds. The number of markers that indicated dehydration levels were counted and categorized into either 3, 2, 1, or 0 WUT markers that indicated dehydration. One-way analysis of variance with Tukey pairwise comparisons was used to assess the differences in urine specific gravity and urine osmolality between the different number of WUT markers. Results: Urine specific gravity in 3 WUT markers (mean ± SD [effect size], 1.021 ± 0.007 [0.57]; P = 0.025) and 2 WUT markers (1.019 ± 0.010 [0.31]; P = 0.026) was significantly higher than 1 WUT marker (1.016 ± 0.009). Urine mosmolality in 2 WUT markers (705 ± 253 mOsmol [0.43]; P = 0.018) was significantly higher than 1 WUT (597 ± 253 mOsmol). Meeting at least 2 WUT markers resulted in sensitivities of 0.652 (2 WUT criteria met) and 0.933 (3 WUT criteria met) to detect urine osmolality >700 mOsmol. Conclusion: These results suggest that when 3 WUT markers are met, urine specific gravity and urine osmolality were greater than euhydration cutoff points. The WUT criterion is a useful tool to use in field settings to assess hydration status when first morning urine sample was used. Clinical Relevance: Athletes, coaches, sports scientists, and medical professionals can use WUT criteria to monitor dehydration with reduced cost and time.

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