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.

Orientador: Maria Aparecida Azevedo Pereira da Silva / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-12T23:35:38Z (GMT). No. of bitstreams: 1 Siqueira_AdrianaCamurcaPontes_D.pdf: 1439498 bytes, checksum: 895ed0eefcd5d01f4f23d10f2f49dcde (MD5) Previous issue date: 2009 / Resumo: Este estudo teve por objetivos: i) avaliar as crenças e atitudes de homens que praticam musculação sobre substâncias ergogênicas; ii) desenvolver e validar uma escala de atitude sobre substâncias ergogênicas para homens que praticam musculação; iii) determinar a prevalência do consumo de ergogênicos na referida população; iv) estudar a imagem corporal desses indivíduos e, v) correlacionar a atitude dos citados indivíduos sobre substâncias ergogênicas com a imagem corporal e o consumo de ergogênicos dos mesmos. Participaram do estudo 100 homens praticantes de musculação, com idades entre 18 e 46 anos. Para avaliar o consumo de ergogênicos, os voluntários responderam a um questionário estruturado, auto-aplicado e anônimo. O desenvolvimento dos itens da escala de atitude sobre ergogênicos foi realizado através de entrevista com 25 indivíduos da população estudada. Na sequência, uma amostra de 100 indivíduos expressou seu grau de concordância a cada item através de uma escala estruturada de 7 pontos (1 = discordo muito; 7 = concordo muito). Para validar a escala desenvolvida foram utilizadas as seguintes metodologias: teste-reteste, consistência Interna e validade de construção. Os construtos de natureza similar aplicados foram: ¿Escala da Catexe Corporal¿, dismorfia muscular diagnosticada através de índices de proporcionalidade antropométrica (B/P), e questionário de dependência de exercício. Adicionalmente o consumo de ergogênicos foi também correlacionado com a atitude dos indivíduos. Os dados foram avaliados através de coeficiente de correlação de Pearson (r), a-Cronbach, ANOVA, Tukey, Wilcoxon ranksum test e Análise de Componentes Principais (ACP). A análise dos dados revelou que 68% dos entrevistados consumiam ergogênicos. Os consumidores tinham em média 27 anos, eram solteiros (82%), sem filhos (88%), possuíam curso superior (62%), e trabalhavam (78%). O consumo médio de ergogênicos foi igual a 3 ergogênicos/indivíduo e a maioria (62%) consumia os ergogênicos diariamente. Os ergogênicos mais consumidos eram os suplementos de proteína (65%), os carboidratos (50%) e os suplementos de aminoácidos (43%). Faziam uso de anabolizantes e estimulantes proibidos no Brasil 10% e 9% dos indivíduos, respectivamente. Os principais motivos para o uso dessas substâncias foram: ¿aumentar a massa muscular¿ e ¿garantir a performance esportiva¿. Apenas 3 % dos indivíduos recebiam orientação médica e 12%, de nutricionista. Uma escala de atitude sobre ergogênicos contendo 22 itens foi desenvolvida e validada. O coeficiente de Cronbach do questionário foi igual a 0,80, garantindo a confiabilidade interna do instrumento. Da mesma forma, o teste-reteste (1 mês) revelou alto grau de correlação entre as duas aplicações do questionário (r = 0,756; p<0,0001), indicando boa reprodutibilidade da escala. Alto grau de correlação foi encontrado entre: consumo de ergogênicos vs. atitude sobre ergogênicos (r = 0,515; p = 0,0007); índices de proporcionalidade antropométrica (B/P) vs. os escores da escala de atitude (r= 0,515; p=0,0007) e índices de proporcionalidade antropométrica (B/P) vs. consumo de ergogênicos (r = 0,690; p<0,0001), garantindo validade de construção à escala desenvolvida. Entre as crenças que melhor segmentaram os grupos destacaram-se: ¿praticantes de musculação devem usar suplementos proteicos¿ (p=0,002); ¿tomando suplementos proteicos consigo acelerar meus resultados na musculação¿ (p=0,014). A ACP dos dados gerados através da escala revelou 7 componentes com autovalores maiores que 1, explicando 59% da variância entre os escores gerados pelos indivíduos. Tanto os consumidores (95%) como os não consumidores de ergogênicos (100%) apresentaram alto grau de satisfação corporal, consequentemente, baixa correlação (r= - 0,284 p= 0,076) foi verificada entre catexe corporal e atitude com relação aos ergogênicos. Alta proporção (80%) dos praticantes de musculação consumidores de ergogênicos foi classificada com suspeita de apresentar dismorfia muscular. Finalmente, dependência de exercício foi detectada tanto entre os consumidores (30%), como entre os não consumidores de ergogênicos (15%). As informações e instrumento desenvolvido nesta pesquisa fornecem subsídios para o planejamento de programas educacionais sobre substâncias ergogênicas a serem implantados em escolas do Brasil / Abstract: This study aimed: i) to assess the beliefs and attitudes of male bodybuilders on ergogenic substances, ii) to develop and to validate a scale of attitude on ergogenic substances for male bodybuilders, iii) to determine the prevalence of consumption of ergogenics substances in the mentioned population, iv) to assess the body image of the cited men, v) to investigate the correlation between attitude towards ergogenics and both the subjects¿ body image and the substances consumption. Participated on the study 100 men, aging between 18 to 46 years, which practiced bodybuilding. To evaluate their consumption of ergogenics, volunteers answered a structured, self-applied and anonymous questionnaire. The development of the items of the attitude scale on ergogenics was carried through interviews with 25 individuals of the studied population. In the sequence, a sample of 100 individuals expressed their degree of egreement/disagreemente to each item using a structured scale of 7 points (1 = very disagree, 7 = very agree). To validate the scale developed the following methodologies were used: test-retest, internal consistency and construct validity. The similar constructs applied were: Body Cathexis Scale, anthropometric indices of proportionality (B/P), an indicator of muscle dysmorphia, and a questionnaire of exercise dependence. Additionally the consumption of ergogenics also was correlated with the attitude of the individuals. The data were evaluated through of the Pearson¿s (r) and a-Cronbach coefficients, ANOVA, Tukey, Wilcoxon rank-sum test and Principal components analysis (PCA). An analysis of the data revealed that 68% of interviewers were using of ergogenics. The consumers of ergogenics were on average 27 years old, single (82%), did not have children (88%), possessed high education (62%) and job (78%). The average consumption of ergogenics was equal to 3 ergogenics/individual; the majority (62%) consumed the ergogenics daily. The most consumed ergogenics were protein supplements (65%), carbohydrates (50%) and supplements of amino acids (43%). Approximately 10% and 9% of the men, respectively, were using anabolic steroids and stimulants banned in Brazil. The main reasons for using those substances were: "increase muscle mass" and "ensure sports performance". Only 3% of individuals received medical and 12% nutritionist supervision for the use of ergogenics. A scale of bodybuilders¿ attitudes and beliefs towards ergogenics, containing 22 items, was developed and validated. The a-Cronbach coefficient was equal to 0.80, ensuring adequate internal reliability to the scale. Similarly, the test-retest (1 month) showed high correlation between the two applications of the questionnaire (r = 0.756, p < 0.0001). This indicates that the developed scale presents good reproducibility. High correlation was found between: consumption of ergogenics vs attitude on ergogenics substances (r = 0.515, p = 0.0007); anthropometric indices of proportionality (B/P) vs attitude on ergogenics substances (r = 0.515, p = 0.0007) and anthropometric indices of proportionality (B/P) vs consumption of ergogenics (r = 0.690, p < 0.0001), ensuring construct validity to the scale developed in this research. Amongst the beliefs that most segmented the groups were: "bodybuilders should use protein supplements¿ (p = 0.002); and "taking protein supplements I can speed up my bodybuilding results" (p = 0.014). The PCA of the data obtained through the proposed scale generated 7 components showing eigenvalues greater than 1.0, explaining 59% of the variance among the individuals score. Both segments of bodybuilders, consumers of ergogenic (95%) and non-consumers (100%), showed high overall body satisfaction. As a consequence, low correlation (r = - 0.284 p = 0.076) was verified between the scores generated by the Body Cathexis Scale and the scores generated by the ergogenic attitude scale. High proportions (80%) of bodybuilders who consumed ergogenics were classified as suspects of presenting muscle dysmorphia. Finally, dependence of exercises was detected among consumers (30%) and non-consumers of ergogenics (15%). The information and instrument developed in this research provide subsidies to the preparation of educational programs on ergogenics to be implemented in Brazilian schools / Doutorado / Consumo e Qualidade de Alimentos / Doutor em Alimentos e Nutrição