Thesis (M.A.)--Miami University, Dept. of Communication, 2008. / Title from first page of PDF document. Includes bibliographical references (p. 42-46).

by Sum Mei Lin. / Thesis (M.B.A.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 80-81). / Questionnaire also in Chinese. / ABSTRACT --- p.ii / TABLE OF CONTENTS --- p.iii / LIST OF FIGURES AND TABLES --- p.v / CHAPTER / Chapter I. --- INTRODUCTION --- p.1 / Business Problem --- p.1 / Background --- p.2 / Research Objectives --- p.5 / Chapter II. --- LITERATURE REVIEW --- p.6 / Conceptual Framework --- p.6 / Conceptual Model --- p.8 / Hypotheses --- p.10 / Chapter III. --- METHODOLOGY --- p.13 / Research Design --- p.13 / Operationalization --- p.13 / Sample and Sampling Method --- p.16 / Data Collection --- p.16 / Data Analysis --- p.17 / Chapter IV. --- RESULTS AND DISCUSSION --- p.19 / Measurement Model --- p.19 / Chapter ´Ø --- Reliability of Measurement / Chapter ´Ø --- Validity of Measuremet / Structural Model --- p.22 / Chapter ´Ø --- Model Fit / Chapter ´Ø --- Parameter Estimates and Variance Explained / Model Refinement --- p.25 / Chapter ´Ø --- Model 2 - Reliability and Validity of Measurement / Chapter ´Ø --- Model 2 - Fit and Structural Equations / Discussion --- p.30 / Chapter V. --- CONCLUSION --- p.34 / Managerial Implications --- p.35 / Chapter ´Ø --- Fostering Favorable Norm / Chapter ´Ø --- "Reducing Disapproval from Family, Friends and Colleagues" / Chapter ´Ø --- Cultivating Favorable Attitude / Limitations --- p.42 / Future Research Directions --- p.44 / APPENDIX / Chapter I --- Questionnaire - English --- p.46 / Chapter II --- Questionnaire - Bilingual --- p.50 / Chapter III --- Sample Distribution of Age Group and Salary Range --- p.54 / Chapter IV --- Sample Distribution of Employer's Industry and Gender --- p.55 / Chapter V --- SPSS Output for Scale Reliability Analysis --- p.56 / Chapter VI --- LISREL Output for Model1 --- p.65 / Chapter VII --- LISREL Output for Model2 --- p.73 / BIBLIOGRAPHY --- p.80

Doctor of Philosophy / Department of Human Nutrition / Valentina M. Remig / The frequency of dietary supplement use has increased in recent years, especially among older adults. National studies estimated 60-65% of older adults were using at least one dietary supplement, typically a multi-vitamin, multi-mineral (MVMM) supplement. Dietary supplement use has been reported to improve the micronutrient intakes of older adults. The current research study focused on the use of dietary supplements, dietary intakes, and impact of vitamin/mineral (VM) supplements on the nutrient intakes of older Kansans. Volunteer subjects, 60+ years of age, were recruited from 35 senior centers across Kansas. Subjects completed a questionnaire asking for demographic information, current health status, and dietary supplement use. Dietary supplement use was verified for 319 subjects. Two subsequent 24-hour diet recalls were completed by 312 subjects. The sample population was primarily white, non-Hispanic females. Nearly 86% of participants used at least one dietary supplement; most commonly MVMM, calcium, vitamin D, and fish oil. Dietary intake analyses compared intakes of dietary supplement (DS) users to non-dietary supplement (NDS) users. DS subjects consumed significantly higher dietary intakes of carbohydrate, fiber, vitamin A, and zinc than NDS subjects. The NDS group consumed undesirably higher intakes of total fat, saturated fat, and sodium. These results support previous findings that DS users consume healthier diets. The impact of VM supplement use on micronutrient intake compared only the intakes of subjects using VM supplements (n=263) to the Dietary Reference Intakes (DRI). Subjects were most likely to have inadequate dietary intakes of vitamin D, calcium, vitamin E, and magnesium. All micronutrient intakes were improved with the inclusion of VM supplements; most improved were vitamin E, folic acid, vitamin D, vitamin B6, and calcium. Despite supplementation, nearly half of subjects still exhibited low intakes of vitamin D, calcium, and magnesium. Supplementation did not consistently exceed the Tolerable Upper Limit established by the DRIs for most nutrients. In conclusion, dietary supplement use was very common in the sample population, DS subjects had generally healthier diets, and VM supplement use improved micronutrient intake without contributing to concern for toxicity.

Aquaculture production is increasing annualy and wild fisheries for fishmeal production remain stagnant. As a consequence, extensive research has been deployed to reduce dietary fishmeal inclusion in feeds of farmed species. Usage of alternative protein sources derived from plants continues to increase with the most popular sources being oilseeds, legumes and cereal grains. The downside of these sources is that most of them could directly be used for human consumption arising legitimate criticism from voices referring to countries where protein shortages lead to malnutrition among the population. Jatropha curcas is a tropical oilseed with upcoming popularity for sustainable fuel sourcing. The plant is thought to thrive in semi-arid and arid areas, not just producing oil, but at the same time reclaiming previously eroded land for the local population. For these reasons, annual cultivation of Jatropha curcas is thought to rise over the next decades. After oil is extracted from the seed, the remaining press cake, is currently used as a fertilizer or energy source. This is mostly due to toxic phorbol esters that until recent- ly limited any nutritional applications. In 2011, a method to detoxify Jatropha press cake was developed and paved the way for nutritional research on the resulting detoxified Jatropha curcas kernel meal (JKM) to be launched. JKM offers very high protein content with a balanced amino acid composition suggesting opportunities for usage as a feedstuff in aquaculture diets. JKM further has higher mineral content than comparable oilseeds. However, potential anti-nutritional factors (ANFs) present in the meal could lead to impairment of nutrient availability or other adverse effects. Previous research has already started to evaluate JKM as a protein source for a variety of aquaculture species. This thesis attempts to further identify the potential of JKM as a protein source and assess the effects of JKM on the development of two model cultured teleost species, common carp (Cyprinus carpio) and Nile tilapia (Oreochromis niloticus), as they represent two of the most farmed species, particularly in the tropics. The work comprises growth trials on both species using fishmeal as a subject of replacement in solely fishmeal protein-based diets and on more practical fishmeal/plant protein-based diets. It engages with the effects of phytate, a prominent component of JKM with potential anti-nutritional attributes and commercially available phytase feed supplements to diminish these attributes, as well as oxalate, another plant-specific component with high concentrations in JKM and with limited attention in aquaculture nutrition research. Carp and tilapia showed varying results with different inclusion levels of JKM. For carp 50% fishmeal replacement was possible without losses in growth in diets where fishmeal was the only bulk protein source (Chapter 3.1), Tilapia showed slightly worse growth at a 30% replacement level (Chapter 3.2). A steep decline in growth could be observed when replacing 100% fishmeal with JKM in carp (Chapter 3.1), while tilapia showed no difference at that level compared to 30% replacement (Chapter 3.2). In practical diets, 100% of fishmeal could be replaced by JKM without any adverse effects on growth of carp (Chapter 3.3), while tilapia showed a slight, but significant linear negative correlation with higher inclusion levels of JKM (Chapter 3.4). Phytase addition in tilapia feeds was identified as having no obvious impact on growth in JKM based diets where enough available phosphorus was provided through mineral supplementation (Chapter 4.1). In JKM based diets where available phosphate was not added, phytase addition showed a tendency to increase growth and significantly increased mineral retention and decreased phosphorus effluent contamination (Chapter 4.2). Phytase application through pre-incubating JKM along with citric acid exerted a positive effect of growth on carp when fishmeal protein was replaced by 50% (Chapter 3.1). Phytase was further shown to completely hydrolyze phytate in vitro; however, incomplete hydrolysis was observed in vivo in tilapia (Chapter 4.3). Dietary soluble oxalate added to fishmeal based diets for carp showed better growth parameters, nutrient and mineral retention at inclusion levels 1.5% and higher (Chapter 5.1). For tilapia, a trial could demonstrate adverse effects of oxalate on potassium, calcium, manganese and zinc digestibilities, in this case without negative effects on growth (Chapter 5.2). For both, carp and tilapia, an impact of oxalate on lipid metabolism was evident, lowering body lipid content and blood cholesterol in inclusion levels from 1.5% or higher. JKM can become a valuable alternative to present dietary protein sources in aquaculture feeds. The nutritional attributes of JKM need further research, especially longer-term testing in a commercial scenario and application in commercially produced feeds. Results of this thesis pose a useful addition to previous research and can be referred to for realizing these next steps.

Thesis (MSc)--Stellenbosch University, 2000. / ENGLISH ABSTRACT: Six groups each with six Friesian bull calves were used in this investigation and slaughtered at 20 weeks of age. Calves received a low- (LD) or high (HD) degradable protein diet, each with or without rumen inert fat supplementation. Two commercial fat sources were used, Morlae (m) and Golden Flake (gf), included at 2.5% of the diet. A commercial milk replacer (Denkavit) was fed at 4L for 42 days, followed by 2L until weaning at 49 days of age. The starter diets were fed ad lib. from day 14 to 10 weeks of age and finishing diets ad lib. from 11 to 20 weeks of age. There were no significant differences in body mass gain or dry matter intake over the entire 20 week period. The feed conversion ratio (FCR) was improved significantly (P=0.0032) when fat was supplemented to LD, but not to HD diets. The FCR (kg dry matter/ kg gain) ofLD, HD, LDm, HDm, LDgfand HDgfdiets were 3.45,3.44,3.07, 3.81, 3.02 and 3.43, respectively. All 36 calves were used in a digestibility trial, using chromium oxide (Cr203) as a marker, during week 18 of the investigation. Digestibility values (%) for the six diets (LD, HD, LDm, HDm, LDgfand HDgf) were 61.74, 65.91, 75.44, 69.00, 75.54 and 67.15 for dry matter, 61.44, 61.60, 71.33, 68.23, 75.44 and 66.12 for crude protein and 58.56, 66.45, 75.98, 70.92, 78.43 and 70.79 for fat, respectively. The dry matter (P=O.OOOl)and fat (P=O.OOOl) digestibilities were only significantly higher when fat was added to LD diets. The crude protein (CP) digestibilities were significantly higher when fat was added to either the LD (P=0.0001) or the HD (P=0.0488) diets. All the calves were slaughtered at 20 weeks of age and the fatty acid content of the meat (m. longissimus) and subcutaneous fat layer adjacent to the 12th rib as well as the meat colour, was determined. The fatty acid composition of the longissimus muscle was changed by feeding the rumen inert fat sources. The three predominant fatty acids found were palmitic, stearic and oleic acids. The palmitic acid (CI6:0) content of the muscle and diet was 24.44 & 20.47,25.97 & 22.57,31.06 & 33.23, 30.98 & 37.91, 34.94 & 31.77 and 29.71 & 32.88 of the total fat for the LD, HD, LDm, HDm, LDgf and HDgf diets, respectively. The C16:0 content was significantly higher in the muscle of the calves receiving the LD diets supplemented with fat (P=0.0008). There was also a significant interaction between the two fat sources and protein degradability (P=0.0065), but only in the LD diets. The stearic acid (CI8:0) content of the muscle and diet was 14.35 & 5.22, 19.65 & 8.61, 17.29 & 4.68, 22.59 & 5.78, 22.27 & 15.54, and 26.48 & 20.15 of the total fat for the LD, HD, LDm, HDm, LDgfand HDgfdiets, respectively. The C18:0 content was significantly higher in the muscle of calves receiving the HD (P=O.OOOl)compared to LD diets. The stearic acid content was also significantly higher when fat was added to LD (P=0.0042) or HD (P=0.0073) diets. The oleic acid (CI8:1) content of the muscle and diet was 36.06 & 21.51,39.99 & 21.11,32.21 & 23.67, 29.13 & 24.59, 25.23 & 18.68 and 35.93 & 16.02 of the total fat for the LD, HD, LDm, HDm, LDgf and HDgf diets, respectively. The linolenic acid (CI8:3) content of the muscle was significantly higher (P=0.0038) when fat was added to LD diets compared to no fat supplementation (0.87 vs. 0.15). The CIELAB values indicated that LD diets resulted in more pink meat. Mean values ofL* =-32.61, 34.19; a* = 7.08, 7.91 and b* = 3.18 and 4.07 were observed for the LD and HD diets, respectively. Meat from the LD diets had significantly lower L*-(P=0.0252), a*-(P=0.0283) and b*-(P=0.0109) values compared to meat from the HD diets. It was concluded that there was a positive response in CP digestibility when rumen inert fats were supplemented to LD or HD diets, although a greater response was shown in the LD diets. The FCR, dry matter and fat digestibility were only increased when fat was added to the LD and not to the HD diets. Similarly, the fatty acid contents of the longissimus muscle of veal calves can be manipulated with the supplementation of rumen inert fat sources, but only when combined with a low protein degradable diet. The low degradable protein diets also produce a more attractive meat colour for the potential veal consumer. / AFRIKAANSE OPSOMMING: Ses behandelings, lae- (LD) of hoë (HD) degradeerbare diëte, elk met of sonder rumeninerte vetsupplementering, is geëvalueer met ses kalwers in elke groep. Twee kommersiële vetbronne is gebruik, nl. Morlae (m) en Golden Flake (gf) teen 'n 2.5% insluitingspeil. 'n Kommersiële melksurrogaat (Denkavit) is aangebied teen 4L1dag tot 42 dae ouderdom, gevolg deur 2L/dag tot speenouderdom op 49 dae. Aanvangsdiëte is ad lib. aangebied vanaf 14 dae tot 10 weke ouderdom en die groeidiëte ad lib. vanafweek 11 tot 20. Daar was geen betekenisvolle verskille in die totale massatoename of die droëmateriaalinname nie. Die voeromsettingsverhouding is betekenisvol verbeter (P=0.0032) in die behandelings waarin rumeninerte vette by LD diëte ingesluit is, maar nie by die HD diëte nie. Die voeromsettingsverhouding (kg droëmateriaalinname / kg massatoename) van die LD, HD, LDm, HDm, LDgf en HDgf diëte was 3.45, 3.44, 3.07, 3.81, 3.02 en 3.43, onderskeidelik. Al 36 kalwers is in 'n verteringsproef gebruik gedurende week 18 van die proef. Chroomoksied (Cr203) is as merker gebruik. Verteerbaarheidswaardes vir die ses diëte was 61.74, 65.91, 75.44,69.00,75.54 en 67.15 vir droëmateriaal, 61.44, 61.60, 71.33, 68.23, 75.44 en 66.12 vir ruproteïen en 58.56, 66.45, 75.98, 70.92, 78.43 en 70.79 vir vet, onderskeilik. Die droëmateriaal- (P=O.OOOl) en vetverteerbaarheid (P=O.OOOI) was slegs betekenisvol hoër wanneer vet by LD diëte gevoeg is en nie by HD nie. Die ruproteïen (RP) verteerbaarheid Stellenbosch University http://scholar.sun.ac.za VI was betekenisvol hoër (P=0.0002) by LD en HD (P=0.0488) diëte met vet supplementering, teenoor geen vet insluiting. Die kalwers is op 20 weke ouderdom geslag en die vetsuursamestelling van die vleis (m. longissimus) en die subkutane vetlaag teenaan die 12de rib, asook en die vleiskleur, is bepaal. Die vetsuursamestelling van die longissimus spier is deur die supplementering van rumeninerte vet verander. Die drie primêre vetsure wat in die vleis voorgekom het, was palmitiensuur, steariensuur en oleïensuur. Die palmitensuur (CI6:0) inhoud van die spier en diëte was 24.44 & 20.47, 25.97 & 22.57, 31.06 & 33.23, 30.98 & 37.91, 34.94 & 31.77 en 29.71 & 32.88 van die totale vet van die LD, HD, LDm, HDm, LDgf en HDgf diëte, onderskeilik. Die C16:0 was betekinisvol hoër in die spiere van kalwers wat die LD diëte met vet supplementering (P=0.0008) ontvang het. Die steariensuur (CI8:0) inhoud van die spier en diëte was 14.35 & 5.22, 19.65 & 8.61, 17.29 & 4.68, 22.59 & 5.78, 22.27 & 15.54, en 26.48 & 20.15 van die totale vet vir die LD, HD, LDm, HDm, LDgf en HDgf diëte, onderskeidelik. Die C18:0 inhoud was betekinisvol hoër in die spiere van die kalwers wat die HD (P=O.OOOI),teenoor LD diëte ontvang het. Die steariensuur inhoud was ook betekenisvol hoër wanneer vet by LD (P=0.0042) of HD (P=0.0031) diëte gevoeg word. Die oleïensuur (CI8:1) inhoud van die spier en diëte was 36.06 & 21.51, 39.99 & 21.11, 32.21 & 23.67, 29.13 & 24.59, 25.23 & 18.68 en 35.93 & 16.02 van die totale vet vir die LD, HD, LDm, HDm, LDgf en HDgf diëte, onderskeidelik. Die linoleensuur (CI8:3) inhoud van die spier was betekinisvol hoër (P=0.0038) in die LD diëte met vet teenoor LD met geen vet supplementering (0.87 vs. 0.15). Die CIELAB waardes van die LD diëte dui op 'n pienker vleiskleur. Gemiddelde waardes van L* = 32.61 & 34.19, a* = 7.08 & 7.91 en b* = 3.18 & 4.07 is vir die LD en HD diëte, onderskeidelik, waargeneem. Die vleis van die LD diëte het 'n betekenisvol laer L*-(P=0.0252), a*-(P=0.0283) en b*-(P=0.0109) waarde in vergelyking met die HD diëte getoon. Die resultate dui daarop dat daar 'n positiewe respons in die ruproteïenverteerbaarheid by die supplementering van rumeninerte vette by LD en HD diëte voorkom, maar die response op die LD diëte is groter. Die voeromsettingsverhouding, droëmateriaal- en vetverteerbaarheid is egter net bevoordeel in die LD met vet en nie in die HD diëte nie. Die vetsuursamestelling van die longissimus spier in die kalf kan gemanipuleer word met die supplementering van rumeninerte vetbronne, maar slegs wanneer dit gekombineer word met lae degradeerbare proteïen diëte. Die lae degradeerbare proteïen diëte produseer ook die mees aanloklike vleiskleur vir die potensiële kalfsvleisverbruiker.

Thesis (PhD)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Background: Abundant evidence supporting the ergogenic effect of caffeine during endurance exercise exists. Single sporting events, laboratory based studies and inappropriate research design questions the applicability of these studies to triathlon performance. Objectives: The main aims of this study were to i) investigate the ergogenic effect of caffeine supplementation during a triathlon; ii) evaluate parameters that could in part explain why caffeine supplementation is ergogenic, iii) investigate possible factors influencing the ergogenicity of caffeine supplementation and iv) investigate possible confounding factors influencing triathlon performance. Methods: A double-blind, randomized, crossover, controlled, clinical field trial was conducted. Performance data (time to complete (TTC), rating of perceived exertion (RPE) and mood state), parameters explaining the mechanism of action (endocrine-stress response, oxidative stress and plasma lactate), factors influencing ergogenicity (lifestyle, gender and genetics) and triathlon performance (general health, energy- and nutrient intake, body composition, training regime, side-effects of caffeine withdrawal- and supplementation and hydration status) was collected during two Olympic-distance triathlons (T1 and T2). Results: Twenty six Caucasian triathletes (Nm=14, Nf=12) participated (age: 37.8±10.6 years, habitual caffeine intake: 412.7±504.8 mg/day, percentage body fat: 14.5±7.2 %, training/week: 12.8±4.5 hours). There was a 3.7% reduction in swim time (33.5±7.0 vs. 34.8±8.1 minutes) (p=0.05*) and a 1.3% reduction in the overall time to complete the triathlon (149.6±19.8 vs. 151.5±18.6 minutes) (p=0.02*) in the caffeine group. Caffeine did not statistically influence mood state (p=0.72) or RPE (p=0.87), however, a trend was observed for decreased RPE values in the caffeine group. Caffeine supplementation made no difference to markers of endocrine-stress, except for cortisol, which increased beyond the effect observed from exercise (p=0.00*). Oxidative stress was more pronounced in the caffeine group, as seen with elevated leukocyte (p=0.05*), lymphocyte (p=0.05*) and monocyte (p = 0.05*) counts. Caffeine facilitated greater blood lactate accumulation (p=0.04*). Lifestyle, menstrual cycle, menopause, oral contraceptive use and CYP1A2 gene polymorphisms did not statistically influence the effect of caffeine supplementation on triathlon performance. The mean energy- and nutrient intake two days before T1 and T2 was low for energy (36.5±17.6 and 38.9±18.2 kcal/kg BW), estimated energy availability (estEA) (27.9±28.0 and 28.8±25.6 kcal/kg fat free mass) and carbohydrate (CHO) intake (4.1±1.6 and 4.6±2.5 g/kg body weight (BW)) compared to recommendations. The pre-event meal was low in CHO (0.7±0.4 and 0.7±0.5 g/kg BW) and only 62% (N=16) ingested a carbohydrate-electrolyte solution during T1 (CHO: 1.6±2.3 g/kg BW) and T2 (CHO: 0.7±0.4 g/kg BW). Eighty-five percent (N=22) used supplements. Seventy-two percent of pre-menopausal (Nf pre-men=5) and 40% of post-menopausal (Nf post-men=2) females were osteopenic. Of the males, 18% (Nm<50 = 2) had low anterior-posterior spine BMD and 33% (Nm>50 = 1) were osteopenic. Caffeine withdrawal presented as headaches (46%, N=12) and flu-like symptoms (38%, N=10). Side effects of caffeine experienced included shakiness (42%, N=11), heart palpitations (38%, N=10) and gastrointestinal disturbances (38%, N=10). Plasma volume and hydration was not influenced (p=0.70). Conclusion: Caffeine enhanced triathlon performance, but the effect was not as pronounced as seen in previous laboratory trials and did not affect RPE or mood state. Caffeine supplementation augments the endocrine-stress response by further increasing cortisol levels beyond that resulting from endurance exercise and it induces leukocytosis, neutrophillia and lymphocytosis, suggesting the primary ergogenic effect of caffeine may result due to stimulation of both the central and autonomic nervous systems. Lifestyle, gender and genetics did not significantly influence caffeine’s effect on triathlon performance in this cohort. The subjects had low energy, estEA and carbohydrate intake and a high prevalence of osteopenia. / AFRIKAANSE OPSOMMING: Agtergrond: Voldoende bewyse rakende die ergogeniese effek van kaffeïen gedurende uithouvermoë oefening bestaan. Enkel sportsoorte, laboratorium studies en ongeskikte navorsingsontwerpe bevraagteken die toepaslikheid van hierdie studies op driekamp prestasie. Doelwitte: Die hoofdoelwitte van die studie was om i) die verbetering van prestasie of ergogeniese effek van kaffeïen supplementasie tydens ‘n driekamp kompetisie waar te neem; ii) om verskeie parameters wat die ergogeniese effek van kaffeïen supplementasie deels te verduidelik te ondersoek, iii) om moontlike faktore wat die ergogeniese effek van kaffeïen supplementasie kan beïnvloed te ondersoek en iv) om moontlike faktore wat Olimpiese-afstand driekamp prestasie kan beïnvloed te ondersoek. Metodes: ‘n Dubbel-blinde, lukrake, oorkruis, gekontroleerde, kliniese veldproef is uitgevoer. Prestasie data (tyd om die driekampe te voltooi, waargenome inspanning en gemoedstoestand), parameters wat moontlik die aksie van kaffeïen kan verduidelik (endokrien-stress respons, oksidatiewe stress en plasma laktaat), faktore wat die ergogeniese effek van kaffeïen kan beïnvloed (lewensstyl, geslag en genetika) en faktore wat moontlik driekamp prestasie kan beïnvloed (algemene gesondheid, energie- en nutriëntinname twee dae voor en op die dag van die driekampe, liggaamsamestelling en beendigtheid, oefening twee dae voord die driekampe, newe-effekte van kaffeïen ontrekking- en supplementasie en hidrasie status) is ingesamel tydens twee Olimpiese afstand driekampe (T1 en T2). Resultate: Ses-en-twintig Kaukasiese driekamp atlete (Nm=14, Nf=12) is ingesluit (ouderdom: 37.8±10.6, daaglikse kaffeïen inname: 412.7±504.8 mg/dag, % liggaamsvet: 14.5±7.2%, oefening/week: 12.8±4.5 uur). Daar was 'n 3.7% afname in swem tyd (33.5±7.0 teenoor 34.8±8.1) (p=0.05*) en 'n 1.3% afname in totale tyd om die driekampe te voltooi (149.6±19.8 teenoor 151.5±18.6) (p=0.02*) in die kaffeïen groep. Kaffeïen het nie ‘n statisties beduidende effek op die gemoedstoestand (p=0.72) of die waargenome inspanning (p=0.87) gehad nie, maar 'n tendens is waargeneem vir laer waargenome inspannings-waardes in die kaffeïen groep. Kaffeïen het geen verskil gemaak aan parameters van die stres respons nie, behalwe vir kortisol, wat verhoog het bo- en behalwe die effek van oefening (p=0.00*). Oksitdatiewe stres was meer uitgesproke in die kaffeïen groep, soos waargeneem deur verhoogde witbloedsel (p=0.05*), limfosiet (p=0.05*) en neutrofiel (p = 0.05*) tellings. Kaffeïen fasiliteer die verhoging in bloedlaktaat vlakke (p=0.04*). Lewensstyl, menstruele siklus, menopause, orale voorbehoedmiddel gebruik en CYP1A2 geen polimorfismes het geen beduidende effek op die vermoë van kaffeïen om driekamp prestasie te beïnvloed gehad nie. Die gemiddelde energie- en nutriëntinname twee dae voor T1 en T2 was laer as die aanbevelings vir energie (36.5±17.6 en 38.9±18.2 kcal/kg LG), geskatte energie beskikbaarheid (29.9±28.0 en 28.8±25.6 kcal/kg vetvrye massa) en koolhidraat (CHO) inname (4.1±1.6 en 4.6±2.5 g/kg LG). Die voor-driekamp ete was laag in CHO (0.7±0,4 en 0.7±0.5 g / kg LG) en slegs 62% (N=16) het ‘n koolhidraat-elektroliet oplossing tydens T1 (CHO: 1.6±2.3 g/kg LG) en T2 (CHO: 0.7±0.4 g/kg LG) ingeneem. Vyf-en-tagtig persent (N=22) gebruik dieetaanvullings. Twee-en-sewentig persent van die pre-menopausale (Nf pre-men=5) en 40% van die post-menopausale (Nf post-men=2) vroue het osteopenie volgens die totale liggaams been mineraal digtheid. Van die mans, het 18% (Nm<50 = 2) met lae beendigtheid van die anterior-posterior spina en 33% (Nm>50 = 1) met osteopenie gepresenteer. Waargenome ontrekkingsimptome van kaffeïen was hoofpyn (46%, N=12) en griepagtige simptome (38%, N=10) en newe-effekte was bewerigheid (42%, N=11), hartkloppings (38%, N=10) en spysverteringskanaal versteurings (38%, N=10). Plasma volume en hidrasie was nie beïnvloed nie (p=0.70). Gevolgtrekking: Kaffeïen verbeter driekamp prestasie, maar die effek is nie so uitgesproke soos waargeneem tydens laboratorium studies nie en het nie ‘n beduidende effek op waargenome inspanning of gemoedstoestand getoon nie. Kaffeïen verhoog die stres respons deur die verdere verhoging van kortisol vlakke, bo- en behalwe vlakke waargeneem tydens uithouvermoë oefening en verhoog witbloedsel, limfosiet en neutrofiel tellings. Dit dui daarop dat die primêre ergogeniese effek van kaffeïen supplementasie moontlik as gevolg van stimulasie van beide die sentrale en autonome senuweestelsel voorkom. Lewensstyl, geslag en genetika het nie ‘n beduidende effek op die ergogeniese vermoë van kaffeïen getoon in hierdie studiepopulasie nie. Die deelnemers het ‘n lae energie, geskatte energie beskikbaarheid en koolhidraatinname gehad. Die studiegroep het ‘n hoë prevalensie van osteopenie.

published_or_final_version / abstract / Zoology / Doctoral / Doctor of Philosophy

The problem of this study was to search for possible effects of the pre-competition meal. This problem had two primary facets: 1) to determine performance scores secured by college varsity track and field men under two different pre-competition meal conditions and to study the relationship of the meal last ingested before competition to the scores; 2) to determine the concern for certain psychological and psycho-physiological factors under each of the two pre-competition meal conditions.

Background: Dietary supplements (DS) use has increased in the U.S. in the past 20 years. More than half of the U.S. population reported using DS. There are few studies to our knowledge that have assessed DS use specifically for older adults. In this study we purposed to evaluate the trend of using DS among older adults and to test the association between using DS and several demographics, socioeconomics and health characteristics. The second objective was to evaluate the reasons behind using DS among older adults using a nationally representative database. Methods: This is a cross sectional study using the most recent National Health and Nutrition Examination Survey (NHANES) database 2009-2012. It is a nationally representative sample of noninstitutionalized adults in the U.S. Frequency and weighted percentage (standard error) were reported for dichotomous variables. Multiple logistic regressions model analyses were used to evaluate the predictors of DS use after testing model assumptions, multicollinearity, and outliers. P values 0.05 were considered significant. All the statistical analyses were conducted using SAS software version 9.4. Results: Out of 2625 older adult participants (65 years and older) 70.5% of them reported using DS in the past 30 days. Female, non-hispanic white, obese, overweight and excellent and very good self-reported health status participants were more likely to use DS. Multivitamin-multiminerals (MVMM), calcium and vitamin D were the most commonly reported supplements among older adults. 71% of oldest old (80≥ years) reported taking DS and prescription medication in the past 30 days concomitantly and 73% of polypharmacy users reported using DS. To stay healthy, to improve overall health and for bone health were the most commonly reported reasons behind using DS. Conclusion: majority of older adult participants reported using DS in the past 30 days. Health care professionals need to evaluate the dietary supplement information from older adults in order to improve health care.

The purpose of this study was to determine the acute effects of caffeine supplementation on strength and muscular endurance in resistance-trained women. In a randomized manner, 15 women consumed caffeine (6 mg/kg) or placebo (PL) seven days apart. Sixty minutes following supplementation, participants performed a one repetition maximum (1RM) barbell bench press test and repetitions to failure at 60% of 1RM. Heart rate and blood pressure were assessed at rest, 60 minutes post-consumption, and immediately following completion of repetitions to failure. Repeated measures ANOVA indicated a significantly greater bench press maximum with caffeine (p<0.05) (52.9 « 11.1 kg vs. 52.1 « 11.7 kg) with no significant differences between conditions in 60% 1RM repetitions (p=0.81). Systolic blood pressure was significantly greater post-exercise, with caffeine (p<0.05) (116.8 « 5.3 mmHg vs. 112.9 « 4.9 mmHg). Our findings indicate a moderate dose of caffeine may be sufficient for enhancing strength performance in resistance-trained women. / by Erica R. Goldstein. / Thesis (M.S.)--Florida Atlantic University, 2009. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2009. Mode of access: World Wide Web.