published_or_final_version / Physiology / Master / Master of Philosophy

Thesis--M. Phil., University of Hong Kong, 1980.

Bibliography: leaves 219-229. / Microfiche. / xiv, 229 leaves, bound ill. 29 cm

Thesis (M. Phil.)--University of Hong Kong, 1980. / Also available in print.

1. Two aspects of long-term salt and water excretion were measured in Glaucous-winged Gulls, Larus glaucescens. Total body water volume and turnover rate were measured in birds drinking fresh water and drinking sea water by THO disappearance rate. Na+, K+, and CI- excretions over 24 hours were measured by continuous collection of cloacal and salt gland excretions from birds fed fish, fish plus a salt load, or a salt load only. 2. Total body water volume was found to be 79% of body weight on both fresh water and sea water drinking regimes. TBW volume is large compared to other birds. 3. Mean total body water turnover rate was the same for both drinking regimes (0.064 ml/g-day); this value is the same as the predicted rate based on data from other birds. 4. There were no significant differences between the fish and fish salt fed birds in the pattern or amounts of ion excretion. 5. Sodium and chloride were excreted in approximately equal amounts from the salt gland and cloaca. Most potassium was excreted via the cloaca. Thirty-eight percent of the total sodium, 6% of the total potassium and 58% of the total chloride excreted were contained in the salt gland secretion of both the fish and fish + salt groups of gulls. 6. The fluid and solid portions of the cloacal excretion were analyzed for ions. Cations were divided between the two portions. In the fish and fish + salt fed birds, 51.8 + 7.8% of the cloacal Na+ and 61.8 + 4.5% of the cloacal K+ was found in the solid portion of the cloacal excreta. Chloride was detected in the fluid portion only. 7. The two birds given only a salt load had lower rates of evaporative water loss and smaller amounts of cloacal solids compared to the fed birds. 8. The large TBW volume may be advantageous to marine birds as a buffer against excess salt ingestion. The constancy of TBW turnover rate suggests that the gulls are specifically adapted to their environment where salt, but not water, is a stress. 9. The results suggest that the salt gland, cloacal fluids and especially the cloacal solids are important routes for ion excretion for fed birds and that osmoregulatory processes for fed and unfed birds may be different. 10. These data imply that although the salt gland is the primary adaptation of marine birds to salt stress, the entire process of salt and water metabolism also involves other more subtle mechanisms. / Science, Faculty of / Zoology, Department of / Graduate

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.

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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 Washington, 2006. / Vita. Includes bibliographical references (leaves 82-94).

Thesis (Ph.D.)--University of Wyoming, 2008. / Title from PDF title page (viewed on August 9, 2009). Includes bibliographical references (p. 160-199).