The aims of this thesis were to; firstly, address the numerous concerns for athletes associated with exercise-induced dehydration and electrolyte loss; secondly, to examine the development of methods of assessing soccer players’ performance; and thirdly, to investigate the inter-relationship between soccer-specific tests. Finally, through a series of studies, the effect of electrolyte loss on subsequent soccer-specific performance was examined. / Chapters 1 and 2 comprise of detailed literature reviews, which introduce the pertinent issues related to hydration, electrolyte loss and assessment of soccer performance and outline areas of necessary future research. Chapter 3 measured the effect of short-term fatigue, through a repeated sprint ability (RSA) test, on subsequent skill performance, via the Loughborough Soccer Passing Test (LSPT), in thirty international level female soccer players. No significant differences were observed in any of the movement, penalty or total time taken to complete the LSPT between the pre- and post-RSA scores. / Chapter 4 investigated the hydration status and electrolyte loss of 14 professional soccer players (mean ± SD; Age: 24.1 ± 3.5 years; Height: 1.78 ± 0.07 m, Body mass (BM): 72.6 ± 12.1 kg) during normal “in-season” training and subsequently examined the effect of beverage sodium (Na⁺) on RSA performance. It was found that RSA performance was significantly improved in professional soccer players by the inclusion of 21.32 mmol·L⁻¹ Na⁺ in a beverage, when compared to a control beverage. / Chapter 5 examined the effects of 60 min of soccer-specific training on LSPT performance, hydration status and core temperature (Tc) when ingesting either a carbohydrate-electrolyte (CHO-E) or control (CON) drink. Seven healthy male soccer players (age: 23 ± 2.9 y, height: 1.7 ± 0.04 m, mass: 62.7 ± 6.7 kg) each completed a carbohydrate-electrolyte (CHO-E) and a control (CON) trial. There was an improvement in movement time (p = .034) and overall LSPT performance (p = .031) post-exercise in CHO-E when compared with CON. No differences were observed in Tc or absolute and relative body mass loss between trials (p> .05). / The final investigation of this thesis is detailed in chapter 6, where the purpose of the investigation was to examine the effect of beverages with different Na⁺ concentrations in soccer players on repeated sprint and soccer skill performance during and after soccer-simulated activity in a hot and humid environment. 12 healthy, male, semi-professional soccer players volunteered for this study (mean ± SD: age 24.5 ± 3.3 y, height 1.8 ± 0.06 m, BM 78.1 ± 9.4 kg). The results highlighted that the RSA performance was improved in both the High-Na⁺ and Na⁺ trials when compared to the CON trial at each time point (p < 0.05). A significant improvement in LSPT performance was observed in the Hi-Na⁺ trial compared with CON trial at all measurement time points (p < 0.05). / The findings from this thesis highlight that the addition of Na⁺ to a beverage can enhance sprint and skill performance in soccer players when the beverage is consumed during sport-specific training in a hot and humid environment. / 本論文的研究目的包括; 首先，探討運動員在運動時脫水和流失電解質的眾多顧慮;其次，考究足球員表現評估方法之發展; 第三，通過一系列的研究，調查電解質流失對隨後足球專項表現的影響。最後，就不同足球專項評估方法的相互關連性進行研究。 / 第1章和第2章包含詳盡的文獻綜述，當中介紹了水合作用、電解質流失和足球員表現評估方法的議題，並帶出未來需要研究的方向。第3章探討透過反复衝刺能力（ RSA ）測試引致的短期疲勞對足球表現的影響。30名國際級女子足球運動員在短期疲勞前後進行LSPT技術測試。結果顯示，RSA前後的LSPT成績 (不論動作、懲罰或總完成時間)均無顯著差異。 / 第4章調查了14名專業足球運動員（平均值±標準差; 年齡： 24.1 ±3.5歲，身高：1.78 ±0.07米，體重（ BM ）：72.6 ±12.1千克）於”比賽季”常規訓練的水合狀態和電解質流失，並隨後研究飲料鈉（Na +）對RSA表現的影響。研究發現， 與對照組相比，運動員飲用包含21.32 mmol.L -1 Na +的飲料後，RSA表現有顯著提升。 / 第5章研究攝入碳水化合物-電解質飲料（ CHO - E）或對照飲料（CON ）後，60分鐘足球專項訓練對LSPT表現，水合狀態和核心溫度（Tc）的影響。七名健康男性足球員（年齡：23 ±2.9歲，高度： 1.7 ±0.04米，體重： 62.7 ±6.7千克）各完成一個碳水化合物-電解質（ CHO - E）和一個對照組（CON ）試驗。與CON組相比，，CHO - E組在運動時間（P = .034 ）和整體LSPT表現（P = .031 ）均有顯著提升。兩組間的Tc或絕對和相對體重流失則無顯著差異（P> 0.05 ）。 / 在最後第6章，本論文研究在高溫高濕環境下的足球模擬活動期間和隨後，不同Na +濃度飲料對足球員的反複衝刺和足球專項技巧表現的影響。 12名健康的男性半職業足球運動員自願參加本研究（平均值±標準差： 24.5 ±3.3歲，身高1.8 ±0.06米，體重78.1 ±9.4千克） 。結果顯示，與CON組相比，高Na +和Na +組在所有測量時間點中的RSA表現都有顯著提高（ P <0.05）。至於LSPT表現，高Na +組則比CON組在所有測量時間點均有顯著改善（ P < 0.05）。 / 綜上所述，本論文的研究結果強調，在飲料添加Na +可提高足球運動員在炎熱和潮濕的環境訓練時的短跑和技術表現。 / O'Reilly, John Timothy. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2014. / Includes bibliographical references (leaves 116-137). / Abstracts also in Chinese. / Title from PDF title page (viewed on 08, November, 2016). / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only.

This thesis examines the ontogeny of plasma sodium regulation (an indicator of osmoregulatory ability), current or rheotactic response (an indicator of emigration timing) and salinity preference in juvenile coho salmon (Oncorhynchus kisutch). The purpose of the study was to determine if there are inherited differences in the development of these traits between coastal and interior British Columbia populations of coho. An interior (Cold water River) and a coastal (Rosewall Creek-Big Qualicum River) population were monitored for the above traits throughout the year. Both wild and laboratory groups were included in the study. The laboratory raised populations were divided into two incubation treatment groups: one incubated under a coastal temperature regime, and the other incubated under an interior temperature regime. There were no differences in the development of sodium regulatory ability between wild populations when the data were sorted by coho weight. Coastal coho, however, physiologically smolted after one year in the natal streams, while interior coho smolted after at least two years of freshwater growth. No obvious differences were noted between wild resident populations in the timing of downstream movement or the shift in salinity preference from hypotonic to isotonic and hypertonic salinities. Both of these behavioural responses typically occurred in the spring (April-May) of each year. Fyke net catches, however, sugqested that, in addition to the spring emigrations observed in both populations, a portion of the interior population migrated in the fall (November). No differences in the development of sodium regulatory ability were observed either within or between laboratory raised populations. Ion regulatory ability increased to a plateau in the fall and winter following emergence, and increased to smolting levels during the following spring (April-May). There were differences between coastal and interior populations in the pattern of development of both nocturnal current responses and the preference for isotonic or hypertonic salinities. Interior laboratory raised coho developed negative nocturnal rheotaxis and a preference for isotonic salinities about three months earlier (November) than laboratory raised coastal coho (late February-March). Within populations, no differences were observed in the ontogeny of these traits in the groups reared under different temperature regimes. Because these interpopulation ontogenetic behavioural differences persisted in fish reared under identical laboratory conditions, they probably have some genetic basis. Such an innate component in behaviour implies an adaptive role and in juvenile coho these behavioural traits may allow populations to use a variety of habitats at different distances from the sea, even though a major physiological schedule (in this case the development of ion regulatory capabilities) appears to be fixed within the species. Perhaps variations in migratory timing and salinity preference in juvenile coho evolved to assure survival in a relatively unstable and often severe environment by optimizing habitat use within the constraints of an overriding physiological schedule. / Science, Faculty of / Zoology, Department of / Graduate

During exercise water and electrolytes are lost in sweat. There is a large variation in both sweat rate and sweat composition and as a consequence sweat electrolyte loss can be large, especially for sodium, the primary cation in sweat. The loss of large amounts of sodium in sweat has been linked with hyponatraemia and muscle cramps. Sodium intake is encouraged in some athletes and in some exercise situations, which is in direct contrast to guidelines aimed at the general population aimed at reducing average sodium intakes to 2.4g of sodium per day (6g salt/day). Dietary sodium intakes have been determined by numerous methods, including weighed dietary records and 24h urine collections. As dietary sodium intake in excess of basal requirement is primarily excreted in the urine in non-sweating individuals, and the basal requirement for sodium is small, 24h urine collections can provide an accurate estimate of dietary sodium intake. In Chapter 3, 24h urinary sodium excretion was measured in eighteen subjects on 4 separate occasions. Subjects consumed their normal diet with the exception of a 5g creatine supplement and 500ml of water, which was part of a separate investigation. The relationship between urine sodium excretion in each 24h collection period was weak, but on average males excreted 200 ± 48mmol of sodium per day and females excreted 157 ± 33mmol of sodium per day, which is equivalent to 4.6g and 3.6g of sodium, respectively. This is in excess of the current recommended intake. In chapter 4, the variation in sodium excretion was determined in eight subjects who consumed the same diet for 5 consecutive days. Despite the similar intake of sodium each day, a day to day variation in sodium excretion of 13% was still observed. This was not related to either sodium intake or potassium intake. In chapter 5, nine subjects consumed their normal diet for 5 consecutive days but weighed and recorded all food and drink consumed. During this period, 24h urine samples were also collected. No strenuous exercise was permitted apart from an exercise task on day 4. This involved intermittent cycling in the heat until 2% body mass (BM) was lost. Sweat was collected from four absorbent patches placed on the back, chest, forearm and thigh. Sweat sodium concentration was adjusted to account for the 35% over-estimation using this regional collection method. Subjects lost 1.51 ± 0.19L of sweat and 66 ± 16mmol (range 32 86mmol) of sodium. There was no difference in sodium balance between each 24h period due to a significant decrease in urine sodium excretion on the day of exercise (day 4). In chapter 6, the effect of prior exercise on sweat composition during a second exercise bout completed later that same day was determined. Eight healthy males cycled for 40 minutes in the heat on one or two occasions. A period of 5h elapsed between exercise bouts when two exercise sessions were performed. Sweat was collected using a whole body washdown method and by 4 absorbent patches placed on the back, chest, forearm and thigh. The main finding was that prior exercise did not affect sweat rate or sweat sodium, potassium and chloride concentrations in the second exercise bout when using the whole body washdown method. Chapter 7 determined the effects of two exercise sessions completed on the same day on electrolyte balance. Nine subjects followed their normal dietary behaviour but weighed and recorded all food and drink consumed during 5 consecutive days. During this period 24h urine samples were also collected. No strenuous exercise was permitted during this period apart from two exercise tasks on day 4. During exercise sweat was collected using a whole body washdown technique. Sweat rate and sweat sodium, potassium and chloride concentrations during the second exercise bout were found to be similar to the first exercise bout. Subjects lost 2.64L (range 1.80 3.48L) of sweat and 138 ± 106mmol of sodium (range 32 287mmol). Sodium balance was not significantly affected on the day of exercise, but urine sodium was lower than dietary sodium intake on the day of exercise (Day 4) and the day following exercise (day 5), indicating significant sodium conservation by the kidney. In contrast, no change in sodium intake was observed. In chapter 8, the effect of skimmed milk and a sports drink in restoring fluid balance was examined following exercise-induced dehydration. Seven physically active males cycled intermittently in the heat until 2% BM was lost. During a 1h rehydration period a sports drink (23mmol Na+/L) or skimmed milk (32mmol Na+/L) was consumed in a volume equivalent to 150% of BM loss. Fluid balance at the end of the 3h recovery period tended to be more positive when milk was consumed. Despite this, no difference in exercise capacity in the heat was observed. This thesis shows that exercise did not increase sodium intake, but this may be due to the already high dietary sodium intake of individuals. Sodium balance was maintained in the majority of individuals due to a significant conservation of sodium by the kidneys. When sweat sodium losses are large, urine sodium conservation may not be sufficient to prevent a negative sodium balance. When no food is consumed in the acute period post-exercise, the higher sodium content of skimmed milk than a sports drink may be partly responsible for the increased retention of the ingested fluid. But this did not enhance subsequent performance in the heat.

No description available.

The purpose of this study was to determine the: 1) knowledge, attitudes, and behaviors toward hydration and fluid replacement among collegiate football players at an NCAA Division I University, overall , and the relationship, if any, by position on the team, number of seasons played, and previous nutrition education; 2) relationship between the athletes’ hydration knowledge, attitudes and behaviors; 3) current sources of nutrition information likely to be used by the football players; and 4) players’ perception of the adequacy of, and barriers to, their fluid intake before, during, and after exercise. The players’ mean Hydration Knowledge Score was 14.2 ± 1.4 out of 17 (83.5%). Common misconceptions included: 60% thought water, rather than sports drinks, should be consumed when exercising for more than one hour; 54% did not believe sports drinks are better at restoring muscle glycogen than water; 47% believed salt tablets kept players from getting dehydrated; and 42% indicated thirst is the best indicator of dehydration. No differences were detected by number of seasons, position or previous nutrition education. / Department of Family and Consumer Sciences

Thesis (Ph. D.)--University of Chicago, 1942. / Lithoprinted. Description based on print version record. Includes bibliographical references.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / This PhD dissertation aimed to review the concept of the nursing outcome Fluid Balance from the Nursing Outcome Classification (NOC) in postoperative patients who underwent cardiac surgery, and develop operational definitions. For so, a concept analysis was carried out according to the Walker and Avant Model (2005), using the integrative review for searching. It was developed from October to December/2010, based on the leading questions: Which indicators allow the body fluid volume assessment on the postoperative period of cardiac surgery? How these indicators are defined and how could they be evaluated? Which features or values are indicative of normal and altered body fluid volume on the postoperative period of cardiac surgery? Water electrolyte balance, thoracic surgery, and postoperative period were used as searching descriptors. The sample consisted of articles which answered at least one of the searching question(s); with full text available through Portal da CAPES, the University of Iowa electronic system, or the interlibrary loan service; in Portuguese, English, or Spanish. Editorials, letters to the editor, qualitative studies, case report studies, proceedings, duplicate articles, and animal research were excluded. The identified works were submitted to a four step evaluation, which resulted on the selection of 48 articles (CINAHL: 12; PubMed: 12; Scopus: 21; Lilacs: 3). Predominated the narrative reviews, cohort, and descriptive studies (level of evidence IV and VI). From the analysis, 14 indicators were identified, plus the 23 present on the Fluid Balance NOC outcome. The integrative review had a limited contribution for the operational definitions construction, mainly due to the nature of the concept of interest. The concept analysis highlighted the attributes: solvent and/or solute movement (active or passive) through semi-permeable membranes and between physiological compartments; effective regulation by homeostatic mechanisms (gradient between hydrostatic and coloidosmotic pressure, electroneutrality, and neurohormonal mechanisms); and maintenance of compartments concentration and volume. The case model represented a healthy individual, with hormonal and fluid compartments control functions preserved, whereas the contrary cases opposed the attributes partially. The borderline cases consisted of morbid situations in which alterations occurred in at most two attributes. The antecedents of fluid balance corresponded to organic, behavioral, and/or environmental conditions that opposed to those listed for the unbalance, or even their absence. The consequences of unbalance encompassed the estates of fluid deficit or excess, as well as the related concepts of hydration, electrolyte balance (sodium) and systemic (volemia) and local (tissue) perfusion. The consequence of balance consisted of the fluid homeostasis or the absence of consequences of unbalance while the empirical referents corresponded to the indicators. The concept analysis allowed its scope delimitation and identify which parameters assure its presence or even its alteration (unbalance). It encompasses the electrolyte balance, perfusion, and hydration phenomena and is beyond the simple measurement and control of fluid intake and output. As initial validity phase of the nursing outcome, it requires the development of experts and clinical research. / Esta tese teve o objetivo de revisar o conceito do resultado de enfermagem EquilÃbrio HÃdrico da Nursing Outcomes Classification (NOC) em pacientes no pÃs-operatÃrio de cirurgia cardÃaca e desenvolver definiÃÃes operacionais. Para isso, realizou-se anÃlise do conceito, segundo o modelo de Walker e Avant (2005), utilizando a revisÃo integrativa para busca. A mesma foi empreendida de outubro a dezembro/2010, com base nas questÃes norteadoras: que indicadores permitem a avaliaÃÃo do volume de lÃquidos corporais no perÃodo pÃs-operatÃrio de cirurgia cardÃaca? Como esses indicadores sÃo definidos e como podem ser avaliados? Quais as caracterÃsticas ou valores indicativos de normalidade e de alteraÃÃo no volume de lÃquidos corporais, no perÃodo pÃs-operatÃrio de cirurgia cardÃaca? Para busca, utilizaram-se os descritores equilÃbrio hidroeletrolÃtico, cirurgia torÃcica e perÃodo pÃs-operatÃrio. A amostra foi composta por artigos que contemplassem pelo menos uma das questÃes norteadoras; com resumo disponÃvel; texto completo acessÃvel pelo Portal da CAPES, pelo sistema eletrÃnico da University of Iowa ou pelo sistema de comutaÃÃo; em portuguÃs, inglÃs ou espanhol. Foram excluÃdos os editoriais, cartas ao editor, estudos reflexivos, relatos de experiÃncia, anais de eventos, produÃÃes duplicadas e pesquisas com animais. ApÃs o levantamento, as produÃÃes foram submetidas a quatro etapas de avaliaÃÃo, que resultaram na seleÃÃo de 48 artigos (CINAHL: 12; PubMed: 12; Scopus: 21; Lilacs: 3). Destacaram-se os estudos de revisÃo narrativa, coorte e descritivos (nÃvel de evidÃncia IV e VI). A partir da anÃlise, identificaram-se quatorze indicadores, alÃm dos vinte e trÃs presentes no resultado EquilÃbrio HÃdrico da NOC. A revisÃo integrativa teve contribuiÃÃo limitada para a construÃÃo das definiÃÃes operacionais, sobretudo devido à natureza do conceito de interesse. A anÃlise do conceito evidenciou os atributos: movimento de solvente e/ou soluto (ativo ou passivo) atravÃs de membranas semi-permeÃveis e entre compartimentos fisiolÃgicos; regulaÃÃo efetiva por mecanismos homeostÃticos (gradiente entre a pressÃo hidrostÃtica e coloidosmÃtica, eletroneutralidade e mecanismos neuro-hormonais); e manutenÃÃo da concentraÃÃo e do volume dos compartimentos. O caso modelo refletiu indivÃduo saudÃvel, com funÃÃes hormonais e de controle dos compartimentos hÃdricos preservadas, enquanto os casos contrÃrios se opuseram aos atributos apenas em parte. Os casos limÃtrofes compreenderam as situaÃÃes mÃrbidas, nas quais ocorrem alteraÃÃo de, no mÃximo, dois atributos. Os antecedentes do EquilÃbrio HÃdrico corresponderam Ãs condiÃÃes orgÃnicas, comportamentais e/ou ambientais que se opunham Ãquelas listadas para o desequilÃbrio, ou mesmo sua ausÃncia. Os consequentes do desequilÃbrio abrangeram os estados de dÃficit e excesso de lÃquidos, bem como os conceitos relacionados de hidrataÃÃo, equilÃbrio eletrolÃtico (sÃdio) e perfusÃo, tanto sistÃmica (volemia) quando localizada (tecidual). Jà o consequente do equilÃbrio consistiu na homeostase hÃdrica ou na ausÃncia dos consequentes de desequilÃbrio, enquanto os referentes empÃricos corresponderam aos indicadores. A anÃlise do conceito permitiu delimitar seu escopo e identificar quais parÃmetros asseguram sua presenÃa ou mesmo sua alteraÃÃo (desequilÃbrio). O mesmo engloba os fenÃmenos de equilÃbrio eletrolÃtico, perfusÃo e hidrataÃÃo e està alÃm da simples mensuraÃÃo e controle das perdas e ganhos de lÃquidos. Como fase inicial da validaÃÃo do resultado de enfermagem, requer o desenvolvimento de pesquisa com experts e clÃnica.

It is known that during fluid restriction, obligatory water losses continue and hypohydration develops and that restricted energy intake leads to a concomitant restriction of all other dietary components, as well as hypohydration, but the specific effects of periods of fluid and/ or energy restriction on fluid balance, electrolyte balance and exercise performance have not been systematically described in the scientific literature. There were two main aims of this thesis. Firstly, to describe the effects of periods of severe fluid and/ or energy restriction on fluid and electrolyte balance; secondly, to determine the effect of electrolyte supplementation during and after energy restriction on fluid and electrolyte balance as well as energy exercise performance. The severe restriction of fluid and/ or energy intake over a 24 h period all resulted in body mass loss (BML) and hypohydration, but whilst serum osmolality increases during fluid restriction (hypertonic hypohydration), serum osmolality does not change during energy restriction (isotonic hypohydration), despite similar reductions in plasma volume (Chapter 3). These differences in the tonicity of the hypohydration developed are most likely explainable by differences in electrolyte balance, with fluid restriction resulting in no change in electrolyte balance over 24 h (Chapter 3) and energy restriction (with or without fluid restriction) producing significant reductions in electrolyte balance by 24 h (Chapter 3; Chapter 4; Chapter 5; Chapter 6; Chapter 7). Twenty four hour combined fluid and energy restriction results in large negative balances of both sodium and potassium, and whilst the addition of sodium chloride to a rehydration solution ingested after fluid and energy restriction increases drink retention, the addition of potassium chloride to a rehydration solution does not (Chapter 4). Supplementation of sodium chloride and potassium chloride during periods of severe energy restriction reduces the BML observed during energy restriction and maintains plasma volume at pre-energy restriction levels (Chapter 5; Chapter 6; Chapter 7). iv These responses to electrolyte supplementation during energy restriction appear to be related to better maintenance of serum osmolality and electrolyte concentrations and a consequential reduction in urine output (Chapter 5; Chapter 6; Chapter 7). Additionally, 48 h energy restriction resulted in a reduction in exercise capacity in a hot environment and an increase in heart rate and core temperature during exercise, compared to a control trial providing adequate energy intake. Whilst electrolyte supplementation during the same 48 h period of energy restriction prevented these increases in heart rate and core temperature and exercise capacity was not different from the control trial Chapter 8). In conclusion, 24-48 h energy restriction results in large losses of sodium, potassium and chloride in urine and a large reduction in body mass and plasma volume and supplementation of these electrolytes during energy restriction reduces urine output, attenuates the reduction in body mass and maintains plasma volume and exercise capacity.

Thesis (Ph. D.)--University of Washington, 2006. / Vita. Includes bibliographical references (leaves 82-94).

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2009. / Härtill 4 uppsatser.