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The thermal environment
Published in Sue Reed, Dino Pisaniello, Geza Benke, Kerrie Burton, Principles of Occupational Health & Hygiene, 2020
A linear relationship has been shown to exist between colour, specific gravity and osmolality of urine (Shirreffs 2003). Consequently, urine specific gravity (Usg) is increasingly being used as a measure of dehydration in sporting and industrial settings. The methodology usually employed utilises refractometers, and self-testing via ‘dip sticks’ is now becoming popular. The US National Athletic Trainers’ Association (NATA) recommends that ‘Fluid replacement should approximate sweat and urine losses, and at least maintain hydration at less than 2% body weight reduction’ (Casa et al. 2000). In its guideline, the American College of Sports Medicine recommends drinking 0.4–0.8 L/h of fluid during exercise, depending on the size of the individual and the level of work/exercise being undertaken (Sawka et al. 2007). Research has shown that body-weight loss levels of 2% or more can be regarded as indicating that an individual is in the early stages of dehydration (Ganio et al. 2007; Casa et al. 2000; Sawka et al. 2007; Cheuvront & Sawka, 2005). The relationship between urine specific gravity and hydration level is illustrated in Table 14.1.
The thermal environment
Published in Sue Reed, Dino Pisaniello, Geza Benke, Principles of Occupational Health & Hygiene, 2020
Ross Di Corleto, Jodie Britton
A linear relationship has been shown to exist between colour, specific gravity and osmolality of urine (Shirreffs, 2003). Consequently, urine specific gravity (Usg) is increasingly being used as a measure of dehydration in sporting and industrial settings. The methodology usually employed utilises refractometers, and self-testing via hydration specific urine test strips is now becoming popular. The US National Athletic Trainers’ Association (NATA) recommends that, ‘Fluid replacement should approximate sweat and urine losses, and at least maintain hydration at less than 2% body weight reduction’ (Casa et al., 2000). In its guideline, the American College of Sports Medicine recommends drinking 0.4–0.8 L/h of fluid during exercise, depending on the size of the individual and the level of work/exercise being undertaken (Sawka et al., 2007). Research has shown that body-weight loss levels of 2 per cent or more can be regarded as indicating that an individual is in the early stages of dehydration (Casa et al., 2000; Cheuvront and Sawka, 2005; Ganio et al. 2007; Sawka et al., 2007). The relationship between urine specific gravity and hydration level is illustrated in Table 14.1.
A Pilot Study in Non-Human Primates Shows No Adverse Response to Intravenous Injection of Quantum Dots
Published in Lajos P. Balogh, Nano-Enabled Medical Applications, 2020
Ling Ye, Ken-Tye Yong, Liwei Liu, Indrajit Roy, Rui Hu, Jing Zha, Hongxing Cai, Wing-Cheung Law, Jianwei Liu, Kai Wang, Jing Liu, Yaqian Liu, Yazhuo Hu, Xihe Zhang, Mark T. Swihart, Paras N. Prasad
Because the micelles encapsulating the quantum dots are similar in size to viruses and large proteins, they may affect the immune system or induce an inflammatory response, which would be indicated by changes in haematological factors (for example, red and white blood cell count) [23]. Accordingly, standard haematological and biochemical markers were monitored. A complete blood count (CBC) was performed at regular intervals, and the results did not suggest any acute toxicity (Fig. 15.2a–j). Similarly, established serum biochemistry assays were performed. The eight important hepatic indicators—alkaline phosphatase (ALP), total protein (TPROT), albumin (ALB), total bilirubin (TBILI), direct bilirubin (DBIL), alanine transaminase (ALT), aspartate transaminase (AST) and gamma glutamyl transaminase (γ-GT)—were measured weekly and showed no sign of liver injury (Fig. 15.2k–r). Indicators of kidney function—blood urea nitrogen (BUN) and creatinine (CRE)—were also normal (Fig. 15.2t, u). Triglycerides (TG), blood glucose (GLU) and cholesterol (CHO) were also in the healthy range throughout the examination period (Fig. 15.2v–x). Prothrombin time (PT) before treatment (Fig. 15.2s) was slightly above the normal range. Values after treatment were slightly lower than those before treatment, but still slightly above the normal range from the literature. Nonetheless, the international normalized ratio (INR, a ratio of PT to that of a normal control, scaled to account for assay sensitivity) ranged from 0.92 to 1.12, indicating normal blood-clotting behaviour. Urine analysis showed that urine specific gravity was 1.01–1.02, which lies in the normal range.
Effects of different dosages of caffeine administration on wrestling performance during a simulated tournament
Published in European Journal of Sport Science, 2019
Raoof Negaresh, Juan Del Coso, Motahare Mokhtarzade, Adriano Eduardo Lima-Silva, Julien S. Baker, Mark E. T. Willems, Sina Talebvand, Mostafa Khodadoost, Farid Farhani
A urine sample was obtained from each participant during baseline measurement and post final wrestling match, to indirectly assess hydration status in each experimental trial. Urine volume was determined by a graduated cylinder, urine specific gravity was measured using a refractometer (RHB-90ATC, Brix, Hongkong) while urine osmolality was calculated by an advanced osmometer (A20, Hettich Benelux, Netherlands). Dehydration index was determined based on four dehydration scores including urine colour, osmolality, specific gravity and creatinine excretion (Armstrong et al., 2010; Hahn & Waldreus, 2013). In addition, gastrointestinal complaints were determined by a questionnaire at the end of the experimental trials (Felippe, Lopes-Silva, Bertuzzi, McGinley, & Lima-Silva, 2016). The gastrointestinal complaints questionnaire consisted of 11 items which each item having a score between 1 and 10, where 1 shows “no problem”, and 10 is “the worst case”.
Effects of whey protein in carbohydrate-electrolyte drinks on post-exercise rehydration
Published in European Journal of Sport Science, 2018
Liang Li, Feng-Hua Sun, Wendy Ya-Jun Huang, Stephen Heung-Sang Wong
The plasma and urine osmolality were measured with an osmometer (Vapor Pressure Osmometer 5520, Wescor Inc., USA). The urine specific gravity (USG) was measured using a USG refractometer (PEN-Urine S. G., ATAGO Co. Ltd., Japan). The plasma albumin was measured with a semi-automatic biochemical analyser (Randox Monza, Randox Laboratories Ltd., UK). The plasma aldosterone concentration was measured using an enzyme-linked immunosorbent assay (ELISA) kit (Human Aldosterone ELISA Kit, Alpha Diagnostic Intl. Inc., San Antonio, USA), and the intra- and inter-assay CV were <5.4% and <9.6%, respectively. The plasma ADH concentration was also analysed using an ELISA kit (Human Antidiuretic Hormone ELISA Kit, CUSABIO Biotech Co. Ltd., Wuhan, China), and the intra- and inter-assay CV were <8% and <10%, respectively.
Effectiveness of hand cooling and a cooling jacket on post-exercise cooling rates in hyperthermic athletes
Published in European Journal of Sport Science, 2018
Tessa Maroni, Brian Dawson, Kimberley Barnett, Kym Guelfi, Carly Brade, Louise Naylor, Chris Brydges, Karen Wallman
Eight hours prior to commencing exercise in the experimental sessions, participants ingested a radiotelemetry pill (CorTemp, HQ Inc., Palmetto, FL, USA) to enable Tc (gastrointestinal) measurement (ingestion of the pill 8–12 h prior to reading is recommended to allow passage of the pill from the stomach into the intestine, giving a more stable Tc reading; Byrne & Lim, 2007). Upon arrival, a mid-stream urine sample (1 mL) was used to determine urine-specific gravity (USG) to assess pre-exercise hydration levels. In cases of hypohydration (USG > 1.030), participants then consumed an additional 500 mL of water. Nude body mass was then measured using a digital platform scale (Model ED3300; Sauter Multi-Range, Ebingen, Germany) to the nearest 0.01 kg. A heart rate monitor (HR; Polar RS400, Finland) was fitted and three skin thermistors (Skin Sensor SST-1, Physitemp Instruments Inc., NJ, USA) were taped to the sternum, left medial forearm and left mid-posterior calf to measure skin temperature (Tsk) via a computerised program (DASYLab Light, National Instruments, Ireland Resources Ltd). Mean Tsk was calculated using the formula of Burton (1935): Tsk = (0.5 × Tsternum) + (0.14 × Tforearm) + (0.36 × Tcalf). Participants then completed a modified version of the Stroop Colour–Word Test (Inquisit 5 Lab, Millisecond Software, Seattle, USA) (Stroop, 1935). Colour names were presented in an incongruent colour, and participants needed to indicate the colour the word that was presented (not its meaning) by key press. Speed and accuracy were equally emphasised. Baseline measurements for Tc, Tsk and HR were then recorded.