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.

Thesis (MNutr)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Background: The Ironman® triathlon is an ultra-endurance event. It has previously been shown that heavy training schedules and racing ultra-endurance events can lead to immune impairment. Evidence supporting the potential role of dietary intake and body composition on immune impairment or upper respiratory tract infections (URTIs) is currently lacking. Aim: To investigate the relationship between dietary intake, body composition and the incidence of URTI in triathletes residing in Port Elizabeth (PE), during training and competition for the Ironman® 2011 triathlon. Method: An observational longitudinal descriptive study with an analytical component was conducted. The study population included triathletes living in PE, who completed an Ironman® distance event one year prior to, and who were training for the April 2011 Ironman®. Habitual dietary intake was assessed with a quantitative food frequency questionnaire; and race dietary strategies with a three day food record. Body composition was determined with anthropometry and the incidence of URTI was assessed with the WURSS-44. A general health screen (SF-36) was also administered. Results: Habitual dietary intake during the three months pre- and post-Ironman® 2011 triathlon was adequate for all nutrients except for carbohydrate intake in female and male participants (pre-Ironman® of 4.0 (1.7) g/kg body weight (BW)/day and 5.4 (1.8) g/kg BW/day; and post-Ironman® 3.0 (1.0) g/kg BW/day and 4.7 (1.5) g/kg BW/day respectively). Carbohydrate-loading strategies were below recommendations with intakes of 6.0 (2.9) and 5.1 (2.5) g/kg BW/day for female and male participants respectively. Race day nutrition strategies were below recommendations for carbohydrate intake. Post-race dietary intake was below recommendations for carbohydrate in the female participants (0.9 (0.5) g/kg BW). Body mass index was 26.6 (3.4) kg/m2 and 26.1 kg/m2 (1.40) for female and male study participants respectively. Body fat percentage was at the upper end for endurance athletes (29.3 (9.4) % and 13.7 (5.1) % for females and males respectively). In this study 25 % of the triathletes (N=20) developed an episode of URTI during the 3 months post-Ironman®. Dietary intake parameters measured three months pre-Ironman® that had a significant influence on URTI were: potassium (p=0.04) and thiamine (p=0.02) and dietary intake parameters measured 3 months post-Ironman® that had a significant influence on URTI were: total protein (p=0.04); isoleucine (p=0.03); leucine (p=0.03); phenylalanine (p=0.03); valine (p=0.02); thiamine (p=0.01); and Beta-tocopherol (p=0.03). Dietary intake parameters measured during the race that had a significant influence on URTI were: selenium (p=0.04); folate (p=0.04) and proline (p=0.02). Body composition did not have a significant influence on URTI. Conclusion: Habitual dietary intake three months pre- and post-Ironman® as well as pre- and post Ironman race strategies were low for carbohydrate. Body composition indicated that athletes were at the upper end associated with endurance sport. There was a relationship found between an episode of URTI and dietary intake. / AFRIKAANSE OPSOMMING: Agtergrond: Die Ironman® driekamp is 'n ultra-uithouvermoë kompetisie. Daar is voorheen bewys dat swaar oefening skedules en ultra-uithouvermoë kompetisies kan lei tot ‘n immuungebrek. Daar is tans ‘n tekort aan wetenskaplike bewyse wat die potensiële rol van dieetinname en liggaamsamestelling op immuungebrek of boonste lugweginfeksies ondersoek. Doel: Die doel van die studie was om ondersoek in te stel oor die verhouding tussen dieetinname, liggaamsamestelling en die insidensie van boonste lugweg infeksies in driekamp atlete woonagtig in Port Elizabeth (PE), tydens oefening en deelname aan die Ironman® 2011 driekamp. Metodes: 'n Waargenome, longitudinale beskrywende studie is gedoen met 'n analitiese komponent. Die studiepopulasie het bestaan uit driekampatlete woonagtig in PE, wat 'n Ironman® afstand kompetisie voltooi het een jaar voor en wat oefen vir die April 2011 Ironman® kompetisie. Gewoontelike dieetinname is bepaal met 'n kwantitatiewe voedselfrekwensie vraelys, en dieet strategieë rondom die byeenkoms met 'n drie dag voedselrekord. Liggaamsamestelling is bepaal met antropometrie en die insidensie van boonste lugweg infeksies is bepaal met die WURSS-44. 'n algemene gesondheid vraelys (SF- 36) is ook ingevul. Resultate: Die gewoontelike dieetinname gedurende die drie maande voor- en na-Ironman® 2011 was voldoende vir alle voedingstowwe, behalwe vir koolhidraat-inname in die vroulike en manlike deelnemers (voor Ironman® 4.0 (1.7) g / kg liggaamsmassa (LM) / dag en 5.4 (1.8) g / kg LM / dag, en na Ironman® 3.0 (1.0) g / kg LM / dag en 4.7 (1.5) g / kg LM / dag onderskeidelik). Koolhidraatlading strategieë was ontoereikend met innames van 6.0 (2.9) en 5.1 (2.5) g / kg BW / dag vir vroulike en manlike deelnemers onderskeidelik. Die inname op die dag van die byeenkoms was onvoldoende vir koolhidraat. Die dieetinname na die byeenkoms was onvoldoende vir koolhidraat inname in die vroulike deelnemers (0.9 (0.5) g / kg LM). Die liggaamsmassa-indeks was 26.6 (3.4) kg/m2 en 26.1 (1.4) kg/m2 vir vroulike en manlike deelnemers onderskeidelik. Persentasie liggaamsvet was aan die boonste grens geassosieer met uithouvermoë oefening atlete 29.3 (9.4) % en 13.7 (5.1) % vir vrouens en mans onderskeidelik. Die insidense van boonste lugweg infeksies was 25% (N=20) gedurende die drie maande na Ironman®. Dieetinname paramters wat gemeet was drie maande voor Ironman® wat beduidende beïnvloed met boonste lugweginfeksies getoon het, was, kalium (p=0.04) en tiamien (p=0.02) en die dieetinname parameters wat drie maande na Ironman® gemeet is en betekenisvolle beïnvloed getoon het met boonste lugweginfeksies was, totale proteïen (p=0.04); isoleusien (p=0.03), leusien (p=0.03), fenielalanien (p=0.03), valien (p=0.02), tiamien (p=0.01), en B-tocopherol (p=0.03). Die dieetinname parameters wat gemeet was tydens die wedloop wat beduidende beïnvloed met boonste lugweginfeksies getoon het na Ironman® 2011 was, selenium (p=0.04), folaat (p=0.04) en prolien (p=0.02). Die antropometriese parameters gemeet het nie beïnvloed op boonste lugweginfeksies gehad nie. Gevolgtrekking: Die gewoontelike dieetinname drie maande voor- en na Ironman® sowel as voor- en na Ironman® kompetisie strategieë was onvoldoende vir koolhidrate. Liggaamsamestelling het aangedui dat atlete aan die boonste grens geassosieer met uithouvermoë oefening geval het. Daar was beduidende beïnvloed gevind tussen dieetinname en boonste lugweginfeksies.