No description available.

No description available.

No description available.

No description available.

Main goal of this thesis was to evaluate differences in eating habits of people who are actively involved in power sport rowing and adult people who make some sport, but only recreationally or do not make any sport at all.

<p>Obesity has ascended to become the primary modifiable cause of death in the United States. New evidence has called into question the utility of BMI – the typical index of obesity – in predicting cardiometabolic disturbances. The distribution of body fatness may be just as important as the total quantity. Intermuscular adipose tissue (IMAT) has emerged as a distinct subset of adipose in skeletal muscle that may be particularly metabolically deleterious. Typically, sections of either the calf or thigh are used as proxy measurements for whole-body IMAT in investigations. However, IMAT dispersion may not be consistent across tissues, instead infiltrating specific muscle or muscle compartments, and these have may have different metabolic consequences. The study described in Chapter 2 was designed to address this possibility and investigate and compare associations among thigh and calf IMAT stores with indices of cardiometabolic health. The strength of the relationship between IMAT and glucose control-related indices of cardiometabolic health was dependent upon anatomic location. Specifically, thigh IMAT is a better predictor of cardiometabolic risk that calf IMAT. </p> <p>Skeletal muscle has gained increased recognition in recent years for its importance in promotion of health and wellness throughout the life course. While treatment models addressing issues of declining muscle mass and strength with age previously focused on older adults, the importance of utilizing a life course model to promote skeletal muscle health at all ages was more recently recognized. There is consistent evidence that higher-protein diets modestly improve body composition. However, women are at greater risk for not meeting protein requirements and seem to be less willing to adopt strategies to achieve greater protein intake, such as protein supplementation, for fear that it may cause ‘bulkiness’. Therefore, the study described in Chapter 3 was designed to critically evaluate the effect of whey protein supplementation on body composition changes in women via a systematic review & meta-analysis of published randomized controlled trials. It was hypothesized that whey protein supplementation would moderately improve body composition but would not cause excessive muscle hypertrophy. Consistent with our hypothesis, whey protein supplementation improved body composition by modestly (<1%) increasing lean mass, without influencing fat mass.</p> <p>Dietary protein and skeletal muscle are conceptually inseparable; protein is often only considered in terms of how it impacts skeletal muscle-related outcomes. However, it is of interest to determine if the proposed beneficial effects of increased dietary protein consumption extend beyond skeletal muscle. Consumption of higher protein diets result in lower resting blood pressure, but the potential for protein to attenuate acute exercise blood pressure responses is unclear. The study described in Chapter 4 was designed to investigate the effects of meals with different amounts of protein on blood pressure responses to exercise in a randomized, cross-over trial. We hypothesized that consuming the higher-protein meal would attenuate the blood pressure responses to exercise and result in a more robust post-exercise hypotensive response. Contrary to our hypothesis, a higher-protein meal does not attenuate exercise-induced blood pressure responses compared to a lower-protein meal. These findings build upon previous research suggesting that the beneficial effect of chronically elevated protein intake on blood pressure is typically not observed in an acute setting by extending these findings to encompass blood pressure responses to acute responses to exercise.</p> <p>The three studies packaged herein utilize different techniques and report on different outcomes, but conceptual threads unite these works which augment the collective findings. Future researchers investigating the effects of protein on skeletal muscle anabolism can: 1) learn of the importance of proper reflection on surrogate measures and potential for anatomic-specific effects from the IMAT findings (Chapter 2), 2) appreciate the relevance of energy and training states in modulating responses from the WP meta-analysis (Chapter 3), and 3) recognize the importance of holistic approaches and employing challenges to reveal heterogeneity from the protein and BP trial (Chapter 4). Taken together, the research presented in this dissertation forwards our understanding of the relations and effects of dietary protein with different components of body composition on cardiometabolic health. </p>

Lok Cheuk-ming, Andy. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 62-73). / Text in English; abstracts in English and Chinese. / Lok Cheuk-ming, Andy. / Acknowledgments --- p.i / Abstract --- p.iii / Table of Contents --- p.vi / List of Tables --- p.viii / List of Figures --- p.ix / Chapter CHAPTER1 --- Introduction --- p.1 / Chapter 1.1 --- Background --- p.1 / Chapter 1.2 --- Purpose --- p.4 / Chapter 1.3 --- Significance of Study --- p.4 / Chapter CHAPTER2 --- Review of Literature --- p.5 / Chapter 2.1 --- "Energy Metabolism During Prolonged, Submaximal Exercise" --- p.5 / Chapter 2.1.1 --- Energy Metabolism in Humans / Chapter 2.1.2 --- Amount of Energy Stores in Body / Chapter 2.1.3 --- Substrates Utilization during Prolonged Exercise / Chapter 2.2 --- Importance of Pre-exercise Nutrition on Exercise Performance --- p.9 / Chapter 2.2.1 --- Pre-exercise CHO Supplementation / Chapter 2.2.2 --- Timing of CHO and Transient Hypoglycemia / Chapter 2.2.3 --- Type of CHO / Chapter 2.2.4 --- Other Nutrients / Chapter 2.3 --- Application of the Glycemic Index to Pre-exercise Nutrition --- p.14 / Chapter 2.3.1 --- Definition of Glycemic Index (GI) / Chapter 2.3.2 --- Ingestion of GI Foods Before Exercise / Chapter 2.3.3 --- Summary of the Previous Findings / Chapter CHAPTER3 --- Methodology --- p.23 / Chapter 3.1 --- General Methods --- p.23 / Chapter 3.2 --- Participants --- p.34 / Chapter 3.3 --- Experimental Design --- p.34 / Chapter 3.4 --- Procedures --- p.37 / Chapter 3.5 --- Prescribed Glycemic Index Meals --- p.39 / Chapter 3.6 --- Analysis --- p.40 / Chapter 3.7 --- Statistical Analysis --- p.41 / Chapter CHAPTER4 --- Results --- p.42 / Chapter 4.1 --- Running Performance --- p.42 / Chapter 4.2 --- Dietary Analysis --- p.43 / Chapter 4.3 --- Physiological Changes At Rest and During Exercise --- p.44 / Chapter 4.5 --- Changes in Perceptual Variables and Heart Rates At Rest and During Exercise --- p.54 / Chapter CHAPTER5 --- Discussion --- p.56 / Recommendation and Applications --- p.61 / References --- p.62 / Appendices --- p.74

Exercícios intensos resultam em depleção acentuada de glicogênio muscular e aumento da lactacidemia, associados ao aumento do cortisol circulante e seus efeitos catabólicos, como a proteólise muscular, ocasionando em menor desempenho físico e comprometendo a qualidade de treinamento do atleta. Diante disso, o presente estudo avaliou o efeito agudo da suplementação de carboidrato sobre o desempenho físico e a resposta hormonal durante e após uma sessão de exercícios intermitentes de alta intensidade. Participaram do estudo 16 corredores com, idade média de 26 ± 5. Os atletas realizaram, em dois momentos distintos [experimental: carboidrato (CHO) e controle: placebo (PLA)], exercícios intermitentes: 12x800 m pausa 1\'30\" a 100% da velocidade média (Vm) 3.000 m. Com relação aos parâmetros de desempenho físico não foram observados efeitos benéficos com a administração de CHO. Os voluntários realizaram o teste em 28,32±1 ,52 min (CHO) e 28,32±1,38 min (PLA). Observou-se aumento significativo da glicemia durante o exercício em ambos grupos, retornando aos valores pré-exercício durante o período de recuperação, indicando acentuada velocidade de captação da glicose após esforços intensos. Quanto à lactacidemia, houve aumento significativo durante o exercício (CHO: 3, 75±1,62 mmol/L PLA: 2, 79±1,69 mmol/L) quando comparado às concentrações pré-exercício (p<0,05). Essas concentrações estiveram significativamente aumentadas durante o exercício no grupo CHO devido a maior disponibilidade de substrato (p<0,05). Entretanto, a suplementação de CHO não diminuiu as concentrações plasmáticas de cortisol durante o exercício. No experimento PLA a concentração de insulina esteve significativamente maior no período de recuperação, como resultado de uma intensa glicogenólise hepática, superando possivelmente o aumento da glicemia no grupo CHO. / Intense exercises result in accentuated depletion of muscular glycogen and increase of the lactacidemy, which are associated to the increase of the circulating cortisol and its catabolic effects like the muscular proteolysis, causing in shorter physical acting, risking the quality of the athlete\'s training. Because of that, the present study evaluated the acute effect of the carbohydrate supplementation on the physical performance and the hormonal response during and after a session of intermittent exercises of high intensity. Sixteen runners, at the average age of 26 ± 5 have participated in the study. The athletes have accomp1ished, in two different trials [(experimental: carbohydrate (CHO) and control: placebo (PLA)], intermittent exercises: 12x800 m pause 1 \'30\" at 100% mean velocity (Vm) 3000 m. ln relation to the physical performance parameters, no beneficial effects were observed at the CHO administration. The athletes have accomplished the test in 28,32±1,52 min (CHO) and 28,32±1,38 min (PLA). A significant increase of the glycemia was observed in both trials during the exercise, going back to the pre-exercising values during the recovery period, indicating an accentuated speed of glucose captation after intense efforts. As to the lactacidemy, there was a significant increase during the exercise (CHO: 3, 75±1,62 mmol/L PLA: 2,79±1,69 mmol/L) when compared to the pre exercising concentrations (p < 0,05). Those concentrations were significantly increased during the exercise in CHO trial due to larger substratum readiness (p < 0,05). However, the CHO supplementation didn\'t reduce the plasmatic concentrations of cortisol during the exercise. In the PLA trial, the insulin concentration was significantly larger in the recovery period as a result of an intense hepatic glycogenolysis possibly overcoming the increase of glycemia in the CHO trial.

During extreme exercise, athletes experience increased inflammation that is similar to the acute phase response. Endurance athletes, distance runners in particular, are also more susceptible to compromised iron stores. This study evaluated inflammation, immune function and iron status in athletes completing a 50K ultramarathon. Twenty-two well-trained distance runners, 11 males and 11 females, were randomized in a double blind manner into--1) those who consumed 300 mg vitamin E and 1000 mg vitamin C (500 mg twice daily) or 2) placebos--for six weeks before and one week following a 50K ultramarathon race. Blood samples were obtained on 13 separate occasions throughout the study: before supplementation, during supplementation, the day before the race, pre-race, mid-race, immediately post-race, 2 hours following the race, and daily for six days following the race. Plasma levels of ascorbic acid and ��-tocopherol were measured by HPLC with electrochemical detection. Inflammatory cytokines, interleukin-6 (IL-6), tumor necrosis factor-�� (TNF-��), and interleukin-1�� (IL-1��) were measured using standard clinical assays. Each subject recorded immune function in an activity log and incidence of illness was tabulated as number of days ill. Ferritin was measured by enzyme immunoassay. Hemoglobin, hematocrit, and total-iron binding capacity (TIBC) and serum total iron were analyzed by standard procedures. Plasma concentrations of ascorbic acid and ��-tocopherol increased significantly in supplemented subjects (p<0.0001). Although the ultramarathon race elicited an inflammatory response, antioxidant supplementation did not alter the responses of IL-6 and TNF-��, which both increased from pre-race to mid-race, post- and post-2 h (Scheffe post-hoc analysis, p<0.0001) and returned to pre-race concentrations by 1 day after the race. Male supplemented subjects had lower IL-1�� concentrations compared to females consuming the supplement or to males consuming the placebo (ANCOVA, gender/time/treatment interaction; p<0.01) at mid-race (p<0.05 females, p<0.005 males), post 1 and 2 days (all p<0.002). Males had significantly higher ferritin levels than the female subjects (ANOVA, p<0.0001); supplementation resulted in lower ferritin concentrations at post-5 days (p<0.02, ANCOVA treatment time interaction, p<0.005). Supplementation did not reduce the days illness among those consuming antioxidants compared to those consuming the placebos. Ferritin not only increases during inflammation, it also is a measure of iron stores. Females had significantly lower levels of iron than the male subjects for each of the iron parameters measured (hemoglobin and hematocrit both p<0.0001, ferritin p<0.001, TIBC p<0.02) excluding serum total iron. The ferritin concentrations measured in the women were indicative of depleted iron stores (<12 ��g/l), and antioxidant supplementation increased hematocrit levels in the female subjects (p<0.05). This investigation indicates that female distance runners need to be aware of an increased susceptibility to iron depletion compared to their male counterparts. Antioxidant supplementation improved hematocrit levels (p<0.05) among female runners and may improve iron status among females with depleted stores. Although other investigations have suggested that antioxidant vitamins decrease exercise induced inflammation, no profound benefit of supplementation was found in this investigation though a response similar to the acute phase response was elicited by the ultramarathon race. Improvements in IL-i and ferritin in response to antioxidant supplementation may indicate that the supplementation was beneficial, but more research is needed to draw definitive conclusions. / Graduation date: 2003

Exercícios intensos resultam em depleção acentuada de glicogênio muscular e aumento da lactacidemia, associados ao aumento do cortisol circulante e seus efeitos catabólicos, como a proteólise muscular, ocasionando em menor desempenho físico e comprometendo a qualidade de treinamento do atleta. Diante disso, o presente estudo avaliou o efeito agudo da suplementação de carboidrato sobre o desempenho físico e a resposta hormonal durante e após uma sessão de exercícios intermitentes de alta intensidade. Participaram do estudo 16 corredores com, idade média de 26 ± 5. Os atletas realizaram, em dois momentos distintos [experimental: carboidrato (CHO) e controle: placebo (PLA)], exercícios intermitentes: 12x800 m pausa 1\'30\" a 100% da velocidade média (Vm) 3.000 m. Com relação aos parâmetros de desempenho físico não foram observados efeitos benéficos com a administração de CHO. Os voluntários realizaram o teste em 28,32±1 ,52 min (CHO) e 28,32±1,38 min (PLA). Observou-se aumento significativo da glicemia durante o exercício em ambos grupos, retornando aos valores pré-exercício durante o período de recuperação, indicando acentuada velocidade de captação da glicose após esforços intensos. Quanto à lactacidemia, houve aumento significativo durante o exercício (CHO: 3, 75±1,62 mmol/L PLA: 2, 79±1,69 mmol/L) quando comparado às concentrações pré-exercício (p<0,05). Essas concentrações estiveram significativamente aumentadas durante o exercício no grupo CHO devido a maior disponibilidade de substrato (p<0,05). Entretanto, a suplementação de CHO não diminuiu as concentrações plasmáticas de cortisol durante o exercício. No experimento PLA a concentração de insulina esteve significativamente maior no período de recuperação, como resultado de uma intensa glicogenólise hepática, superando possivelmente o aumento da glicemia no grupo CHO. / Intense exercises result in accentuated depletion of muscular glycogen and increase of the lactacidemy, which are associated to the increase of the circulating cortisol and its catabolic effects like the muscular proteolysis, causing in shorter physical acting, risking the quality of the athlete\'s training. Because of that, the present study evaluated the acute effect of the carbohydrate supplementation on the physical performance and the hormonal response during and after a session of intermittent exercises of high intensity. Sixteen runners, at the average age of 26 ± 5 have participated in the study. The athletes have accomp1ished, in two different trials [(experimental: carbohydrate (CHO) and control: placebo (PLA)], intermittent exercises: 12x800 m pause 1 \'30\" at 100% mean velocity (Vm) 3000 m. ln relation to the physical performance parameters, no beneficial effects were observed at the CHO administration. The athletes have accomplished the test in 28,32±1,52 min (CHO) and 28,32±1,38 min (PLA). A significant increase of the glycemia was observed in both trials during the exercise, going back to the pre-exercising values during the recovery period, indicating an accentuated speed of glucose captation after intense efforts. As to the lactacidemy, there was a significant increase during the exercise (CHO: 3, 75±1,62 mmol/L PLA: 2,79±1,69 mmol/L) when compared to the pre exercising concentrations (p < 0,05). Those concentrations were significantly increased during the exercise in CHO trial due to larger substratum readiness (p < 0,05). However, the CHO supplementation didn\'t reduce the plasmatic concentrations of cortisol during the exercise. In the PLA trial, the insulin concentration was significantly larger in the recovery period as a result of an intense hepatic glycogenolysis possibly overcoming the increase of glycemia in the CHO trial.