Urine Specific Gravity Values Research Articles

Urine concentrating ability in cats with hyperthyroidism: Influence of radioiodine treatment, masked azotemia, and iatrogenic hypothyroidism.

Hyperthyroid cats often have urine specific gravity (USG) values <1.035. It remains unclear how USG changes after treatment, if USG can be used to predict azotemia after treatment, or how iatrogenic hypothyroidism influences USG values. To determine the proportion of hyperthyroid cats with USG <1.035 vs ≥1.035; if USG changes after treatment; and whether USG <1.035 correlated with unmasking of azotemia or hypothyroidism. Six hundred fifty-five hyperthyroid cats treated with radioiodine; 190 clinically normal cats. Prospective, before-and-after study. Hyperthyroid cats had serum thyroxine, thyroid-stimulating hormone, and creatinine concentrations, and USG measured before and 6 months after successful treatment with radioiodine. Of untreated hyperthyroid cats, USG was ≥1.035 in 346 (52.8%) and <1.035 in 309 (47.2%). After treatment, 279/346 (80.6%) maintained USG ≥1.035, whereas 67/346 (19.4%) became <1.035; 272/309 (88%) maintained USG <1.035, whereas 37/309 (12%) became ≥1.035. Only 22/346 (6.4%) with USG ≥1.035 developed azotemia after treatment, compared with 136/309 (44%) with <1.035 (P < .001). Of cats remaining nonazotemic, 38% had USG <1.035, compared with 20% of normal cats (P < .001). The 137 cats with iatrogenic hypothyroidism had lower USG after treatment than did 508 euthyroid cats (1.024 vs 1.035), but USGs did not change after levothyroxine supplementation. USG <1.035 had high sensitivity (86.1%) but moderate specificity (65.2%) in predicting azotemia after treatment. Hyperthyroidism appears not to affect USG in cats. However, cats with evidence of sub-optimal concentrating ability before radioiodine treatment (USG < 1.035) are more likely to develop azotemia and unmask previously occult chronic kidney disease. Iatrogenic hypothyroidism itself did not appear to affect USG values.

Point-of-Care Saliva Osmolarity Testing for the Screening of Hydration in Older Adults With Hypertension

Older adults have an elevated risk of dehydration, a state with proven detrimental cognitive and physical effects. Furthermore, the use of diuretics by hypertensive patients further compounds this risk. This prospective study investigated the diagnostic accuracy of point-of-care (POC) salivary osmolarity (SOSM) measurement for the detection of dehydration in hypertensive adults with and without diuretic pharmacotherapy. Prospective diagnostic accuracy study. Home visits to patients recruited from 4 community health centers in West Sulawesi, Indonesia. A total of 148 hypertensive older adults (57 men, 91 women). The mean ages of male and female patients were 69.4 ± 11.4 and 68.1 ± 7.8years, respectively. Hypertensive adults were divided into 2 groups based on the presence of diuretics in their pharmacotherapeutic regimen. First-morning mid-stream urine samples were used to perform urine specific gravity (USG) testing. Same-day SOSM measurements were obtained using a POC saliva testing system. Both USG (P= .0002) and SOSM (P < .0001) were significantly elevated in hypertensive patients with diuretic pharmacotherapy. At a USG threshold of ≥1.030, 86% of diuretic users were classified as dehydrated compared with 55% of non-using participants. A strong correlation was observed between USG and SOSM measurements (r= 0.78, P < .0001). Using a USG threshold of ≥1.030 as a hydration classifier, an SOSM threshold of ≥93 mOsm had a sensitivity of 78.6% and a specificity of 91.1% for detecting dehydration. Hypertensive patients on diuretics have significantly higher first-morning USG and SOSM values, indicating a higher likelihood of dehydration relative to those on other classes of antihypertensive medication. POC SOSM assessment correlates strongly with first-morning USG assessment, and represents a rapid and noninvasive alternative to urinary hydration assessment that may be applicable for routine use in populations with elevated risk of dehydration.

Habit or lack of education? Hypohydration is present in elite senior judo athletes even during a weight-stable training camp

It has been well-documented that high-level judo athletes presented a high level of hypohydration during weight-cutting and competition periods. However, there is a lack of studies investigating the hydration status of high-level judo athletes during a weight-stable training period. Therefore, this study aimed to investigate elite judo athletes’ hydration status, body mass change, and fluid intake during a weight-stable training camp. Twenty-seven judo athletes (women n = 8, men n = 19, body weight = 79.6 ± 20.9 kg) from the senior national judo team voluntarily participated in this study. Data were collected in the morning after waking up and before and after the morning and evening training sessions. On the second day, the measurements were taken again in the morning after waking up. Urine-specific gravity (USG) was classified as hydrated (USG &lt; 1.020) and hypohydrated (USG ≥ 1.020). The athletes’ USG values measured on two consecutive mornings increased (1.025 ± 0.007 to 1.029 ± 0.006) during 24 h, in which athletes performed judo training in the morning and evening. Moreover, sex and weight category did not affect the changes in USG values ( p &gt; .05). Most of the elite judo athletes presented hypohydration (92.6%). The relationship between the fluid intake of the athletes and the changes in USG and body weight values during 24 h was not significant ( p &gt; .05). The current study’s findings revealed that high-level judo athletes present a high level of hypohydration even during a weight-stable training camp. Furthermore, the training sessions during the experiment period (24 h) worsened the hydration status of the senior athletes in all weight categories for both women and men.

Fluid intake, hydration status and body mass changes in U-15 judo athletes during a training day

Despite numerous studies related to dehydration there is still a lack of scientific literature presenting hydration status and fluid intake of judo athletes during different periods. Therefore, the aim of this study was to investigate, fluid intake, hydration status and body weight changes of young judo athletes during a typical day of training in preparation period. Twenty-two young judo athletes (age: 12 ± 0.7 y, experience: 3.5 ± 1.1) voluntarily participated in this study. Hydration status and weight were examined in the morning, before and immediately after the training. All athletes trained 90 min and they consumed fluids ad libitum during the exercise. According to morning urine specific gravity (USG) values, 81.2% of the athletes were dehydrated while only 18.8% of the athletes were euhydrated. Pre-training urine measurements showed that 63.64% of the athletes presented dehydration and 77.27% of the athletes completed the training in dehydrated condition despite fluid availability during the training. Mean body weight loss during training was -0.64 ± 0.66%. It can be concluded that young judo athletes presented high prevalence of dehydration as indicated by USG values. Most of the athletes were dehydrated during a typical training day and completed the training in more dehydrated conditions compared to pre training values despite ad libitum fluid intake. It is of great importance to evaluate hydration status of the athletes before training to refrain from common practice of fluid restriction for weight loss and adverse effects of a persistent state of fluid deficit on physical and health related state.

Changes in body mass and hydration status in judo athletes before and after a top-level competition: a descriptive case study

ABSTRACT Objectives The International Judo Federation (IJF) implemented new regulations in an attempt to regulate rapid weight loss in 2013. The body weight of the athletes cannot be more than 5% higher than the upper limits of their weight categories at the weight check for randomly selected athletes from each weight category before the competition. However, therea lack of studies demonstrating rapid weight loss and hydration status of elite judo athletes in a real match atmosphere under the current refereeing rules. Thus, this study aimed to examine the body mass and hydration changes of elite judo athletes a week before the competition, official weigh-in, and 24 hours after competition. Methods Eight high-level male judo athletes voluntarily participated in this study. Body mass and urinary measures of hydration status were collected a week before, at the official weigh-in and 24-hour post-weigh-in. Results The one-way repeated-measures ANOVA showed a significant main effect of time on body mass (p < 0.001). Body mass decreased by 5.4 ± 0.7 kg or 6.8% from a week before the competition to official weigh-in (p < 0.001) and increased by 3.0 ± 1.1 kg or 4.2% from official weigh-in to 24-h post-competition (p < 0.001). A significant effect of time was also found in both urine-specific gravity (USG) (p < 0.001) and urine color (UC) among the measurements (p = 0.001). Athletes’ USG values were at the highest level (USG = 1.030 ± 0.001) at the official weigh-in, while they decreased significantly at 24-hour post-competition (USG = 1.017 ± 0.007). Conclusion The results showed that elite judo athletes resort to rapid weight loss and present dehydration despite established regulations by the IJF.

Improving hydration in elite male footballers during a national team training camp - an observational case study.

[Purpose] The purpose of this study was to (i) assess hydration levels in elite male football players during a national team training camp before and during qualifying matches, (ii) evaluate the effect of coaching strategies for hydration based on feedback from hydration monitoring, and (iii) assess possible relationships between hydration status and training load or wellness markers.[Methods] Thirty-one male players (age 27±4 yrs; height 185±6 cm; weight 82.9±6.7 kg; body fat 10.4±2.3%) representing a national team from the Union of European Football Associations (UEFA) participated. The players were studied during three different national team training camps related to the UEFA Nations League tournament. Urine specific gravity (USG) was measured to assess hydration status. During all camps, the players were actively coached on improving strategies for hydration and given individual feedback on their test results. The training load was measured using GPS technology, and wellness questionnaires were completed.[Results] USG decreased progressively and significantly (p<0.005) during camp 1 and hydration status improved over the three camps, with fewer dehydrated and more well-hydrated players identified during the last part of camp 3. Significantly (p<0.05) higher USG values were observed 2 days prior to a match (MD-2) than on match day (MD); consequently, 52% of the players were dehydrated on MD-2 and only 6% on MD. No correlations were observed between hydration status and training load or wellness markers.[Conclusion] Dehydration is a challenge in elite male football, but continuous monitoring of hydration status and coaching on hydration strategies can lead to major improvements and reduce the degree of dehydration.

Dehydration and Rapid Weight Gain Between Weigh-in and Competition in Judo Athletes: The Differences between Women and Men

ABSTRACT This study aimed to investigate the sex differences in short-term weight change and hydration status in judo athletes. Thirty-five men and 15 women judo athletes voluntarily participated in this descriptive and repeated measures design study. Body mass, urine-specific gravity (USG), and body composition of the athletes were measured at the official weigh-in and the competition day’s morning. Body mass of the athletes increased during recovery time between official weigh-in and before the competition (time factor; F1-48 = 71.81, p < 0.001), this increase was higher in men athletes compared to women athletes (time-sex interaction; F1-48 = 6.56, p = 0.01). With RWG, USG values of the women and men athletes decreased (time factor; F1-48 = 8.53, p = 0.005). However, most of the athletes were still in significant or serious dehydration state. Unchanged values of total body water rates (TBW) supported dehydration in athletes before the competition (time factor, F1-48 = 2.9, p = 0.091; time-sex interaction; F1-48= 2.4, p = 0.122). The findings of the study indicated that RWG was higher in men athletes compared to women athletes, but hydration status was not affected by sex factor.Notwithstanding 15 hours of recovery between official weigh-in and the start of the competition, judo athletes were still in dehydrated state despite remaining within the limit set for RWG.

+3179G/A Insulin-Like Growth Factor-1 Receptor Polymorphism: A Novel Susceptibility Contributor in Anti-Ro/SSA Positive Patients with Sjögren's Syndrome: Potential Clinical and Pathogenetic Implications.

Background: Alterations of the insulin-like growth factor (IGF) pathway along with genetic variations of the IGF1 receptor (IGF1R) gene have been linked to the development of systemic autoimmunity, possibly through apoptosis induction. This study aims to investigate whether genetic variations of the IGF1R contribute to Sjögren’s syndrome (SS) pathogenesis and explores potential functional implications. Methods: DNA extracted from whole peripheral blood derived from 277 primary SS patients, complicated or not by lymphoma, and 337 Healthy controls (HC) was genotyped for the rs2229765 IGF1R polymorphism using the RFLP-PCR assay. Gene expression of IGF1R and IGF1 isoforms, caspases 1, 4, and 5, and inflammasome components NLRP3, ASC, IL1β, IL18, IL33, IGFBP3, and IGFBP6 were quantitated by RT-PCR in total RNA extracted from minor salivary gland biopsies (MSGs) of 50 SS patients and 13 sicca controls (SCs). In addition, IGF1R immunohistochemical (IHC) expression was assessed in formalin-fixed, paraffin-embedded MSG tissue sections derived from 10 SS patients and 5 SCs. Results: The prevalence of the A/A genotype of the rs2229765 IGF1R polymorphism was significantly higher in the anti-Ro/SSA positive SS population compared to healthy controls (24.8% vs. 10.7%, p = 0.001). Moreover, IGF1Rs at both mRNA and protein levels were reduced in SS-derived MSGs compared to SCs and were negatively associated with caspase 1 transcripts. The latter were positively correlated with NLRP3, ASC, and IL1β at the salivary gland tissue level. IGF1R expression in peripheral blood was negatively correlated with ESR and IgG serum levels and positively correlated with urine-specific gravity values. Conclusions: The rs2229765 IGF1R variant confers increased susceptibility for seropositive primary SS. Dampened IGF1R mRNA and protein expression in salivary gland tissues could be related to increased apoptosis and subsequently to the activation of inflammasome pathways.

Hydration Status in Adolescent Alpine Skiers During a Training Camp.

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.

Effects of Rapid Weight Loss on Kidney Function in Combat Sport Athletes.

Even though scientific literature shows numerous heath complications and performance decrements associated with rapid weight loss (RWL), its prevalence remains exceedingly high across various combat sports. The aim of this study was to thoroughly search the existing literature to explore the influence of RWL on kidney function in Olympic and non-Olympic combat sport athletes. PubMed and Web of Science were searched for the relevant studies. Only original articles published from 2005 onwards, written in English, that included healthy males and females who prompted ~5% weight loss within a week or less, were included in the study. Retrieved studies showed that creatinine, blood urea nitrogen and urine specific gravity values were significantly increased after RWL in the majority of the included studies. This observation indicates that RWL caused dehydration and subsequent acute kidney damage despite various degrees of weight lost during the RWL phase, which can lead to adverse events in other body systems. Alternative methods of weight reduction that prioritize athletes’ health should be considered.

Comparison of canine urine specific gravity measurements between various refractometers in a clinical setting.

Veterinary facilities might use multiple refractometers and individuals to measure urine specific gravity (USG). Previous comparison studies show conflicting results. Furthermore, the clinical significance of measurement differences and interobserver variabilities has not been assessed. We aimed to determine statistically and clinically significant differences between four refractometers in measuring canine USG and subsequent categorization of urine concentrations and azotemia and determine the variability between different observers performing USG measurements. Fifty-nine specimens were included for the USG measurements with four refractometers by different observers. Each refractometer pair was compared using Spearman's rank correlation, Bland-Altman difference plots, and Deming regression analyses. Calculated bias was compared to set performance goals. Interobserver agreement was evaluated, and intraclass correlation coefficients were used to determine differences in the categorization of urine concentrations and azotemia (prerenal or renal). There was excellent correlation (rs =.99-1.00) between refractometers. All comparisons involving R4 showed significant constant and proportional biases. Mean bias met the clinical performance goals for all refractometers, except for comparisons with R4, where up to 17 results were outside the allowable bias. There was almost perfect agreement (rs =.999) between observers and excellent agreement (ICC=.96-.99) for the classification of urine concentrations. In azotemic patients (22%), there was perfect agreement (ICC=1.00) for the categorization of azotemia. In most cases, three of the refractometers evaluated in this study can be used interchangeably at all USG values, without affecting clinical decision-making. Multiple observers did not significantly affect decision-making.

Dietary Intake, Hydration Status, and Body Composition of Three Belgian Military Groups.

Malnutrition, suboptimal hydration, and inadequate body composition can have negative consequences on soldiers' performance and health. A recent consensus statement concerning "soldiers' physical performance" points to the scarcity of data in specific military populations. Therefore, the aim of the present study was to assess and compare dietary intake, hydration status, and body composition of three military groups during their specific military training. Eighty-five soldiers (ie, 21 in a qualification course to join the Special Forces [SF], 22 Infantrymen [Chasseurs Ardennais, CA], and 42 Recruits [REs]) participated in this 3- to 4-day study. Body mass was assessed before and after each study period. All soldiers self-reported their dietary intakes, from which energy and macronutrient intakes were calculated. In addition, their morning urine samples were collected daily to assess urine specific gravity (USG) as a measure of hydration status. Fat mass was estimated at the end of the study using bioelectrical impedance analysis. All groups lost significant amounts of body mass (ie, mean losses ranging between 1.3 and 1.7kg). Macronutrient intakes were not fully met in respect to the recommendations. Most notably, REs' fat intake was high (ie, 42.3 [±1.6] energy percent [E%]), while their carbohydrate intake was low (ie, 44.5 [±2.1] E%). Furthermore, saturated fat intakes were high among all groups (ie, group means ranging between 13.6 and 21.4 E%). USG values indicated suboptimal hydration status was prevalent in all groups. Most noteworthy, for SF, only 5.4% of the USG values indicated optimal hydration. The average fat mass (%) for SF, CA, and RE was 11.2 (±3.1), 18.8 (±5.1), and 19.4 (±5.0), respectively. The present study showed that military men are not always adequately fed nor hydrated. These issues should be resolved by creating nutritional packages, and individual dietary and hydration strategies, all in function of military planning and weather conditions.

Influence of preanalytic and analytic variables in canine and feline urine specific gravity measurement by refractometer.

Urine specific gravity (USG), which is usually measured by refractometry, is an important indicator of renal concentrating ability. Few studies have evaluated refractometers with separate scales for canine and feline urine. Variables such as protein content or storage time may influence the USG. We compared the effects of measuring USG with a refractometer with single or separate scales for canine and feline urine, investigated inter- and intra-observer variability, and measured agreement between whole urine and supernatant. We evaluated the correlation between USG and osmolality, the influence of urinary protein on USG and osmolality, and the impact of storage time up to 6 mo. We examined 252 canine and 126 feline samples. Bland-Altman analysis revealed higher USG values of the single-scale refractometer than the dual-scale refractometer, with a mean difference (bias) of < 0.001 for canine and 0.003 for feline specimens. Inter- and intra-observer variability were acceptable. Good agreement was shown between USG of whole urine and supernatant. Correlations between USG and osmolality were excellent (0.98-0.99, p < 0.001). Proteinuria up to 1 g/L had no major impact on USG or osmolality. Storage time had no significant effect on USG. The difference between the refractometers is clinically irrelevant, and the use of a refractometer with separate feline and canine scales is unnecessary. Whole urine and supernatant stored up to 6 mo can both be used for USG measurement. The influence of proteinuria <1 g/L on USG and osmolality is negligible.

A 4-d Water Intake Intervention Increases Hydration and Cognitive Flexibility among Preadolescent Children

Hydration effects on cognition remain understudied in children. This is concerning since a large proportion of US children exhibit insufficient hydration. This study investigated the effects of water intake on urinary markers of hydration and cognition among preadolescents. A 3-intervention crossover design was used among 9- to 11-y-olds [n=75 (43 males, 32 females); 58.2±28.5 BMI percentile]. Participants maintained their water intake [ad libitum (AL)] or consumed high (2.5 L/d) or low (0.5 L/d) water for 4 d. The primary outcomes were performance on cognitive tasks requiring inhibition, working memory, and cognitive flexibility assessed using a modified flanker, go/no-go, and color-shape switch tasks, respectively. Secondary outcomes included urine hydration indices [i.e., color, urine specific gravity (USG), osmolality] assessed using 24-h urine collected during day 4 of each intervention. Repeated-measures ANOVAs were used to assess intervention effects. There was a significant difference in hydration across all 3 interventions. Urine color during the low intervention [median (IQR): 6 (2)] was greater than during AL [5 (2)], and both were greater than during the high intervention [18 (0)] (all P≤0.01). Similarly, osmolality [low (mean ± SD): 912±199 mOsmol/kg, AL: 790±257.0 mOsmol/kg, high: 260±115 mOsmol/kg] and USG [low (mean ± SD): 1.023±0.005, AL: 1.020±0.007, high: 1.005±0.004] during the low intervention were greater during AL, and both were greater than during the high intervention (all P≤0.01). USG and osmolality AL values were related to switch task measures (β: 0.21 to -0.31, P<0.05). Benefits of the high intervention were observed during the switch task, whereby participants exhibited 34% lower working memory cost relative to the low intervention. No significant changes in cognition were observed for the flanker and go/no-go tasks. The water intervention improved urinary markers of hydration and had selective benefits during task switching. Furthermore, children's cognitive flexibility selectively benefits from greater habitual hydration and water intake. This study is registered at clinicaltrials.gov as NCT02816450.

Hydration Status and Fluid Needs of Division I Female Collegiate Athletes Exercising Indoors and Outdoors.

The purpose was to determine differences in acute and chronic hydration status in female student-athletes (n = 40) practicing in moderate, dry conditions (17–25 °C, 30–57% humidity) indoors and outdoors. Body weight and urine samples were recorded before and after exercise as well as fluid intake. Sweat rates expressed as median and interquartile range did not differ, but fluid intake was significantly higher during indoor (0.64 [0.50, 0.83] L/h) vs. outdoor conditions (0.51 [0.43, 0.63] L/h), p = 0.001. Fluid intake compensated for indoor sweat rate but not outdoors. When exercising indoors, 49% of the student-athletes reported urine specific gravity (USG) values >1.020, and 24% of the day after morning samples were scored ≥4 on the color chart rating. The percentages increased to 58% and 31%, respectively, when exercising outdoors (p > 0.05). Thus, fluid intake was higher indoors vs. outdoors but sweat rate did not differ among athletes. Yet, chronic hydration status was impaired in more than 50% of the student-athletes with a discrepancy between USG scores and urine color scores identifying underhydration. This suggest that 24-h fluid intake should be taken into account and that hydration protocols may need to be tailored individually based on urine USG values. Practice location (indoors vs. outdoors) may further complicate hydration protocols.

Calorie-Containing Recovery Drinks Increase Recreational Runners' Voluntary Energy and Carbohydrate Intake, with Minimal Impact on Fluid Recovery.

This study assessed voluntary dietary intake when different beverages were provided within a recovery area following recreational exercise. Participants completed two 10-km runs 1 week apart. Immediately after the first run, "beer drinkers" (n = 54; mean ± SD: age = 23.9 ± 5.8 years, body mass [BM] = 76 ± 13kg) randomly received low-alcohol beer (Hahn Ultra® [Lion Co.], 0.9% alcohol by volume) or sports drink (SD; Gatorade® [PepsiCo]), whereas "nonbeer drinkers" (n = 78; age = 21.8 ± 2.2years, BM = 71 ± 13kg) received water or SD. Participants remained in a recovery area for 30-60min with fluid consumption monitored. The following week, participants received the alternate beverage. Participants recorded all food/fluid consumed for the remainder of both trial days (diary and photographs). Fluid balance was assessed via BM change and urine specific gravity. Paired t tests were used to assess differences in hydration and dietary variables. No differences were observed in preexercise urine specific gravity (∼1.01) or BM loss (∼2%) between intervention groups (ps > .05). Water versus SD: No difference in acute fluid intake was noted (water = 751 ± 259ml, SD = 805 ± 308ml, p = .157). SD availability influenced total energy and carbohydrate intakes (water = 5.7 ± 2.5MJ and 151 ± 77g, SD = 6.5 ± 2.7MJ and 187 ± 87g, energy p = .002, carbohydrate p < .001). SD versus beer: SD availability resulted in greater acute fluid intake (SD = 1,047 ± 393ml, beer = 850 ± 630ml; p = .004), which remained evident at the end of trial days (SD = 3,337 ± 1,100ml, beer = 2,982 ± 1,191ml; p < .01). No differences in dietary variables were observed. Next day, urine specific gravity values were not different between water versus SD. However, a small difference was detected between SD versus beer (SD = 1.021 ± 0.009, beer = 1.016 ± 0.008, p = .002). Consuming calorie-containing drinks postexercise appears to increase daily energy and carbohydrate intake but has minimal impact on next-day hydration.

High prevalence of hypohydration in occupations with heat stress-Perspectives for performance in combined cognitive and motor tasks.

PurposeTo evaluate the prevalence of dehydration in occupational settings and contextualize findings to effects on performance in cognitively dominated tasks, simple and complex motor tasks during moderate and high heat stress.MethodsThe study included an occupational part with hydration assessed in five industries across Europe with urine samples collected from 139 workers and analyzed for urine specific gravity. In addition, laboratory experiments included eight male participants completing mild-intensity exercise once with full fluid replacement to maintain euhydration, and once with restricted water intake until the dehydration level corresponded to 2% bodyweight deficit. Following familiarization, euhydration and dehydration sessions were completed on separate days in random order (cross-over design) with assessment of simple motor (target pinch), complex motor (visuo-motor tracking), cognitive (math addition) and combined motor-cognitive (math and pinch) performance at baseline, at 1°C (MOD) and 2°C (HYPER) delta increase in body core temperature.ResultsThe field studies revealed that 70% of all workers had urine specific gravity values ≥1.020 corresponding to the urine specific gravity (1.020±0.001) at the end of the laboratory dehydration session. At this hydration level, HYPER was associated with reductions in simple motor task performance by 4±1%, math task by 4±1%, math and pinch by 9±3% and visuo-motor tracking by 16±4% (all P<0.05 compared to baseline), whereas no significant changes were observed when the heat stress was MOD (P>0.05). In the euhydration session, HYPER reduced complex (tracking) motor performance by 10±3% and simple pinch by 3±1% (both P<0.05, compared to baseline), while performance in the two cognitively dominated tasks were unaffected when dehydration was prevented (P>0.05).ConclusionDehydration at levels commonly observed across a range of occupational settings with environmental heat stress aggravates the impact of hyperthermia on performance in tasks relying on combinations of cognitive function and motor response accuracy.

Pre-Training Hydration Status of Well- Trained Soccer Players in Moderate Temperature Autumn and Cool Winter

Background. Pre-training hydration status is considered a factor influencing efficacy of training. Research literature does not contain data regarding the potential impact of natural alternation of seasons on pre-training hydration status in athletes. The purpose of this study was to assess and compare pre-training hydration status in well-trained male soccer (football) players in moderate temperate autumn and cold winter.Methods. Research participants were 57 male soccer players from two Latvian First League teams, who were studied prior to their ordinary training session. Participants provided a midstream urine sample for analysis of urine specific gravity (USG), and their body mass (kg), body fat percentage and total body water percentage were measured. Results. Pre-training hydration status did not differ in moderate temperature autumn (mean USG 1.020 ± 0.010; mean total body water 64.2 ± 2.9%) in cold winter (mean USG 1.020 ± 0.008; mean total body water 64.8 ± 2.7%; for both parameters p &gt; .05). Prevalence of hypohydration and serious hypohydration (defined as USG 1.021 – 1.030 and USG &gt; 1.030, respectively) was similar in moderate temperate autumn (47.4%) and cold winter (60%), (χ 2 = 1.50; p &gt; .05). Significant correlation between the within-subject USG values measured in moderate temperate and cold environment was observed (r = .60, p = .009). Conclusion. In well-trained soccer players pre-training hydration status does not differ in moderate temperature autumn and cold winter. Individual-related factors such as nutritional behaviour (including pattern of voluntary fluid intake) may have stronger impact on hydration status than environment-related factors like natural alternation of seasons.Keywords: hydration status, football, environmental temperature, autumn, winter.

Pregame Hydration Status of Collegiate Basketball Players on Consecutive Days of Play

Collegiate basketball teams typically compete on non-consecutive days, allowing players ample time to recover from fluid loss incurred during a game and return to a euhydrated state before the next contest. However, some NCAA conferences, tournaments and invitationals require play on consecutive days, possibly leading to greater occurrences of hypohydration, which could impair performance and/or increase injury risk. PURPOSE: To evaluate pregame hydration status of collegiate basketball players on consecutive days of competition and determine if these measures are associated with game performance. METHODS: Twenty-five collegiate basketball players (14 men, 11 women) from a NCAA Division II university participated in this study. Players’ urine specific gravity (USG) and body weight (BW) were assessed 1-2 hours prior to the start of 8 pairs of regular season conference games (16 games total) played on consecutive days (Fri & Sat). Upon arrival to the locker room, each athlete was weighed on a digital scale, wearing similar clothing each time, and provided a urine sample. USG was assessed using a hand-held clinical refractometer. Box score data were used to calculate player efficiency (PE) ratings as measures of in-game statistical performance. RESULTS: On Sat, 61.8% of players had a BW deficit (-0.60 ± 0.42 kg) compared to Fri, with 20.2% presenting with a BW deficit ≥ 1%; however, Fri vs. Sat BW differences were not significant (P = 0.693). Overall, 25.2% of players had USG values 1.020-1.024 and 27.0% of players had USG values ≥ 1.025 before their games. Players had USG values ≥ 1.020 more often on Fri (56.2%) than Sat (48.2%), though this difference did not reach statistical significance (P = 0.834). Neither changes in BW (P = 0.659) nor USG (P = 0.854) from Fri to Sat were significantly associated with PE on Sat. CONCLUSION: Approximately 50% of players were mildly to severely hypohydrated before the start of each game; yet hypohydration rates were similar before games played on consecutive days. Still, the majority of players had modest BW deficits before games played on the second day, indicating insufficient rehydration from the prior game. Although collegiate basketball players were consistently hypohydrated before their games, hydration status was not associated with statistical performance in these contests.

A Nutrition Recovery Station Following Recreational Exercise Improves Fruit Consumption but Does Not Influence Fluid Recovery.

Immediate postexercise access to fruit/fluid via a recovery "station" is a common feature of mass participation sporting events. Yet little evidence exists examining their impact on subsequent dietary intake. The aim of this study was to determine if access to fruit/water/sports drinks within a recovery station significantly alters dietary and fluid intakes in the immediate postexercise period and influences hydration status the next morning. 127 (79 males) healthy participants (M ± SD, age = 22.5 ± 3.5y, body mass (BM) = 73 ± 13kg) completed two self-paced morning 10km runs separated by 1 week. Immediately following the first run, participants were randomly assigned to enter (or not) the recovery station for 30min. All participants completed the alternate recovery option the following week. Participants recorded BM before and after exercise and measured Urine Specific Gravity (USG) before running and again the following morning. For both trial days, participants also completed 24h food and fluid records via a food diary that included photographs. Paired-sample t tests were used to assess differences in hydration and dietary outcome variables (Recovery vs. No Recovery). No difference in preexercise USG or BM change from exercise were observed between treatments (p's > .05). Attending the recovery zone resulted in a greater total daily fluid (Recovery = 3.37 ± 1.46L, No Recovery = 3.16 ± 1.32L, p = .009) and fruit intake (Recovery = 2.37 ± 1.76 servings, No Recovery = 1.55 ± 1.61 servings, p > .001), but had no influence on daily total energy (Recovery = 10.15 ± 4.2MJ, No Recovery = 10.15 ± 3.9MJ), or macronutrient intakes (p > .05). Next morning USG values were not different between treatments (Recovery = 1.018 ± 0.007, No Recovery = 1.019 ± 0.009, p > .05). Recovery stations provide an opportunity to modify dietary intake which promote positive lifestyle behaviors in recreational athletes.