3 pp. / discontinued 3/4/11 / Nutrition misinformation, myths, fraud, and quackery can prevent athletes from attaining optimal performance. This publication provides a list of criteria to evaluate the myriad of information in the media surrounding the athlete and ergogenic aids.

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The purpose of this thesis was to determine ways to maximize creatine uptake and retention during creatine supplementation. Since there are many factors that affect muscle creatine concentrations, a series of studies were performed. In the first study, the purpose was to determine if á-lipoic acid aided creatine uptake and retention. It was hypothesized that á-lipoic acid would increase creatine uptake, because it has been found to increase glucose disposal in animal studies and because creatine uptake has been found to be related to increased glucose transport. Results showed that phosphocreatine and total creatine increased following supplement intervention. In the second study, the purpose was to develop an optimal dose of creatine in order to minimize urinary excretion of creatine. It was hypothesized that individuals with more lean tissue mass would excrete less urinary creatine during consumption of the same loading dose. There was a high negative correlation between lean tissue mass and urine creatine excretion. Regression equations were developed for the relationship between lean tissue mass and urine total creatine and used to determine the amount of creatine to ingest relative to lean tissue mass that would result in minimal creatine losses in urine. Based on these results, a creatine dose of 0.22 [right arrow] 0.25 g/kg lean tissue mass/d was recommended. In the third study, the purpose was to determine if a habitual vegetarian diet resulted in lower muscle creatine and phosphocreatine concentrations compared to an omnivorous diet. A secondary purpose was to determine if creatine supplementation and weight training resulted in greater increases in muscle metabolite content, muscle fiber area, lean tissue mass, and strength in vegetarians compared to non-vegetarians. Results indicated that vegetarians had lower resting total creatine concentration, and that creatine supplementation and weight training led to greater increases in muscle phosphocreatine and total creatine in vegetarians compared to non-vegetarians (p < 0.0125). The supplement and exercise intervention eliminated the differences in intramuscular total creatine concentration that existed prior to the study. Type II muscle fiber area, lean tissue mass, total work output, and 1-RM bench press increased to a greater extent following creatine supplementation compared to placebo supplementation (p < 0.017), with no difference between vegetarians and non-vegetarians. (Abstract shortened by UMI.)

The use of nutritional supplements (NS) is common in able-bodied (AB) athletic populations and good evidence exists for a number of NS such as sports drinks, protein powder, creatine, caffeine and buffering agents. However, little evidence is available regarding the popularity and efficacy of NS in a population of athletes with physical impairments.

Orientador: Fausto Berzin / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-13T18:13:58Z (GMT). No. of bitstreams: 1 Silva_DanielaCristinadeOliveira_D.pdf: 6119887 bytes, checksum: b62dec11acd94575dd460ba847dfc7a3 (MD5) Previous issue date: 2009 / Resumo: A eletromiografia de superfície é um instrumento potencial para estudos anatômicos, clínicos e cinesiológicos da atividade elétrica muscular e tem sido aplicada para identificar padrões de ativação muscular associados com força e fadiga muscular. A suplementação de creatina tem sido utilizada para aumentar a força e eficiência muscular, bem como diminuir o início da fadiga muscular. Assim, o objetivo deste trabalho foi analisar a atividade eletromiográfica e força dos músculos bíceps braquial (BB), braquiorradial (BR) e flexor ulnar do carpo (FUC) em indivíduos submetidos à suplementação aguda e crônica de creatina. Vinte indivíduos do sexo masculino, idade 18-35 anos, treinados em exercícios resistidos (musculação), foram selecionados para este estudo duplo-cego, randomizado, placebo-controlado. Os voluntários foram divididos em dois grupos: creatina (5 g de creatina e 5 g de maltodextrina, n=10) e placebo (5 g de celulose e 5 g de maltodextrina, n=10). A suplementação foi ingerida quatro vezes ao dia durante os primeiros 7 dias, e uma vez ao dia durante os 49 dias subsequentes. Cada voluntário realizou contração voluntária isométrica máxima (CVIM) de flexão do antebraço e com 30% e 60% da CVIM, antes e após 7 e 56 dias de suplementação. Os sinais eletromiográficos foram captados utilizando eletrodos de superfície passivos conectados a um pré-amplificador, registrados em um eletromiógrafo computadorizado, e analisados pelo software Myosystem-Br1. Uma célula de carga foi empregada para medir a força isométrica máxima durante os testes. Os dados eletromiográficos foram calculados pelos valores de amplitude (RMS - root mean square) e freqüência mediana (FM), e analisados por meio de curva de regressão linear, gerando coeficientes angulares de RMS e FM que foram considerados índices de eficiência e fadiga muscular, respectivamente. Os resultados mostraram que o grupo creatina exibiu aumento da força somente após 56 dias de suplementação (p < 0,05), enquanto nenhuma diferença foi encontrada no grupo placebo. Os músculos BB e BR mostraram decréscimo nos valores de coeficientes angulares de RMS após 7 e 56 dias de suplementação de creatina com 60% da CVIM (p < 0,05). Nenhuma diferença significante foi observada nos valores de coeficientes angulares de FM entre os tempos de suplementação para todos os músculos, em ambos os grupos e cargas. Assim, pode ser concluído que a suplementação crônica de creatina aumenta a força isométrica de flexão do antebraço. Além disso, tanto a suplementação aguda como a crônica de creatina melhoram a eficiência muscular de BB e BR apenas com cargas maiores, porém não tem efeito benéfico na redução da fadiga muscular de BB, BR e FUC, em qualquer intensidade de carga / Abstract: Surface electromyography is a potential tool for anatomic, clinic and kinesiologic studies of muscle electric activity and it has been employed to identify muscular activation levels associated with force and muscular fatigue. Creatine supplementation has been used to augment the strength and muscular efficiency as well to decrease the onset of muscular fatigue. This study aimed to analyze the force and electromyographic activity of biceps brachii (BB), brachioradialis (BR) and flexor carpi ulnaris (FCU) muscles in subjects submitted to acute and chronic creatine supplementation. Twenty resistance-trained male volunteers, aged 18 to 35 years, were selected for this double-blind, controlled-placebo, randomized study. Volunteers were placed into two groups: creatine (5 g creatine and 5 g maltodextrine, n=10) and placebo (5 g cellulose and 5g maltodextrine, n=10). Oral supplementation was given 4 times per day during the first 7days and once a day in the 49 subsequent days. Volunteers performed maximum isometric voluntary contraction (MIVC) of forearm flexion and with 30% and 60% MIVC, before and after 7 and 56 days of supplementation. Electromyographic signs were captured using passive surface electrodes joined to a pre-amplifier, recorded in a computer-connected electromyography and analyzed by the Myosystem-Br1 software. A load cell was used to measure the maximum isometric strength during the tests. Electromyographic data were calculated by values of amplitude (RMS - root mean square) and median frequency (MF) and analyzed by linear regression curve, generating RMS and MF slopes that were considered muscular efficiency and fatigue indices, respectively. Results showed that creatine group exhibited an increase of strength only after 56 days of supplementation (p < 0.05), while no significant difference was found in placebo group. BB and BR muscles showed a decrease of RMS slopes after 7 and 56 days of creatine supplementation with 60% MIVC (p < 0.05). No significant difference was observed in MF slopes among times of supplementation for all muscles in both loads and groups. It can be concluded that the chronic creatine supplementation increases the isometric strength of forearm flexion. Also, both acute and chronic creatine supplementation improve the BB and BR muscular efficiency only with high loads, but do not have beneficial effect on reducing muscular fatigue of BB, BR and FCU, whichever the load / Doutorado / Anatomia / Doutor em Biologia Buco-Dental

The purpose of this investigation was to determine the effects of a four day creatine load and simultaneous energy restriction on muscle creatine content, exercise performance, and body composition in 24 male recreational resistance trainers, age 18-26. Sixteen subjects were randomly divided into placebo (Pl, n=8) and creatine supplement (CrS, n=8) groups. Control (C, n=8) subjects of the same age were recruited separately g à d-1 to complete the performance and body composition tests while consuming their normal diet. The CrS group was administered 20 g à d-1 of creatine monohydrate (Cr) mixed with 5 g à d-1 of sucrose, while the Pl group was administered 25 of sucrose. Both CrS and Pl consumed a formula diet of 75.3 kJ (18 kcal) à kg-1 à d-1 for 4 d. Testing before and after energy restriction consisted of a repeated sprint cycle performance test (10 sprints of 6s, with 30s rest), hydrostatic weighing, and resting needle muscle biopsy. Testing revealed that subjects in CrS and Pl demonstrated significant decreases in body weight and % body fat (%BF) with no difference between groups. However, Pl demonstrated a significantly greater % loss in FFM (2.4 ± 0.25%) compared to CrS (1.4 ± 0.4%) (p<0.05). The muscle fuel stores of CrS and Pl responded significantly to the diet. Significant increases in muscle total Cr (p<0.01), free Cr (p<0.01), and CrP (p<0.05) of 16.5%, 16.8%, and 16% respectively were demonstrated by CrS over the energy restriction period, while Pl demonstrated significant decreases of 7.2% and 8.2% respectively in muscle total Cr (p<0.01) and free Cr (p<0.05). There were no significant differences between groups for performance during the cycle test, however, there were trends toward group by time interactions for performance enhancement in CrS relative to Pl, as total work (p=0.078) and work capacity (p=0.058) increased 3.8 ± 2.2% in CrS and decreased 0.5 ± 0.4% in Pl. It was concluded that short-term energy restriction resulted in decreased muscle Cr storage, and that Cr supplementation during energy restriction increased muscle Cr and CrP stores. Consumption of Cr allowed CrS to lose a significantly lower % FFM compared to Pl. Cr supplementation resulted in trends toward improved performance in CrS relative to Pl after energy restriction, but did not influence losses in body weight or %BF. / Master of Science

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This thesis examined four key areas considered to contribute to why the efficacy of sodium bicarbonate (NaHCO3) as an ergogenic aid remains equivocal. Firstly, familiarisation to and test re-test reliability of continuous constant load cycling to exhaustion (TLIM) at 110% peak power output (WPEAK) were investigated. Results indicated two trials are required before participants become fully familiarised and reliable data are obtained and that daily biological variation was 6 ± 11% (16 ± 28 s). The primary aim of study two was to determine the most appropriate exercise intensity for future studies in this thesis. A secondary aim was to elucidate why certain participants appear to respond to NaHCO3 ingestion and others do not (Price and Simons 2010, Saunders et al. 2011). Therefore, we evaluated cycling TLIM at 100%, 110% and 120% WPEAK in the same participants. NaHCO3 ingestion increased TLIM by 17% compared to placebo (PLA) at 100% WPEAK. This was due, at least in part, to attenuated localised ratings of perceived exertion (RPEL). No difference in group level data was observed between treatments at 110% WPEAK or 120% WPEAK although there was marked inter and intra individual variance. Thirdly, in order to evaluate the efficacy of NaHCO3 at a tissue level we examined the effects of NaHCO3 on dynamic isolated muscle performance undergoing cyclical length changes. Acute power output (PO) was on average 7.0% greater for NaHCO3 treated extensor digitorum longus (EDL) muscles and 3.6% greater for NaHCO3 treated soleus (SOL) muscles compared to control (CON). Increases in PO were due to greater force production throughout shortening. Treatment of EDL and SOL did not alter the pattern of fatigue at a group level although similar to study 2 there was marked inter individual variation. Finally, to determine the effects of training status we evaluated the effects of 6 weeks high-intensity cycling training on the efficacy of NaHCO3. Overall, pre-training TLIM was 10% greater with NaHCO3 compared to PLA with a benefit to harm odds ratio of 571. Overall, post-training TLIM was 6% greater with NaHCO3 compared to PLA with a benefit to harm odds ratio of 17. Similar to studies 2 and 3 individual variation was observed. Based on daily biological variation for TLIM of 6% (as determined in study 1) and a recommended benefit to harm odds ratio threshold of > 66, NaHCO3 improved TLIM before training only. We concluded that 6 weeks high-intensity cycling training reduces the effectiveness of NaHCO3 in previously non-cycling trained males. The change in efficacy is likely due to, at least in part, training induced changes in intracellular buffering capacity. In summary, NaHCO3 is an effective ergogenic aid for TLIM cycling at 100% WPEAK in non-cycling trained males. This is due, at least in part, to attenuated localised ratings of perceived exertion (RPEL). In contrast, 6-weeks high-intensity cycling training reduces the efficacy of NaHCO3 for TLIM cycling at 100% WPEAK in previously non-cycling trained males. The change in efficacy is likely due to, at least in part, training induced changes in intracellular buffering capacity. At a skeletal muscle level, NaHCO3 increases acute PO in both predominantly fast (EDL) and predominantly slow (SOL) twitch muscle fibres, due to greater force production throughout shortening.

Respiratory muscle training (RMT) has been shown to improve exercise tolerance during a wide range of exercise modalities and durations of activity (McConnell & Romer, 2004b). However, there is a limited amount of research characterising the influence of RMT in specific athletic populations, or examining any sport-specific factors that may influence the benefits of RMT. Hence, the purpose of this dissertation was to evaluate the application of RMT in competitive rowers and to explore methods of optimising this to rowing. Results: Inspiratory muscle training (IMT) increased inspiratory muscle strength (~20-29%; p < 0.05) and attenuated inspiratory muscle fatigue (~8-28%; p < 0.05) during time trial performance in club-level and elite rowers. However, only in the club-level oarsmen was IMT associated with a measurable improvement in rowing performance (2.7% increase in mean power; p < 0.05). Expiratory muscle training (EMT) provided no ergogenic effect, and concurrent EMT and IMT did not enhance performance above that seen with IMT alone. IMT loads performed at 60-70% of maximal inspiratory mouth pressure (PImax) were equivalent to the widely used 30 repetition maximum, which is higher than reported for non-rowers (Caine & McConnell, 1998a); further, a load of 60% PImax was sufficient to activate the inspiratory muscle metaboreflex, as evidenced by a time-dependent rise in heart rate (70.1 ± 13.2 to 98.0 ± 22.8 bpm; p < 0.05) and mean arterial blood pressure (92.4 ± 8.5 to 99.7 ± 10.1 mmHg; p < 0.05). Higher and lower inspiratory loads did not activate the metaboreflex. Assessments of flow, pressure and volume in rowing relevant postures revealed no significant impairments, but optimal function occurred in the most upright postures. Conclusions: These data support the application of IMT, but not EMT, in elite and sub-elite rowers, and suggest that a load of 60-70% of PImax provides metaboreflex activation during loading. Further, the data do not support a requirement to undertake IMT in rowing relevant postures.

O objetivo do trabalho foi investigar o efeito da suplementação isolada de cafeína e bicarbonato de sódio sobre a contribuição dos sistemas energéticos, desempenho e reativação parassimpática após simulação de luta de taekwondo. Para tanto, a presente tese foi dividida em estudo 1, com a suplementação de cafeína e estudo 2, com a suplementação de bicarbonato de sódio. Portanto, no estudo 1, o objetivo foi investigar o efeito da suplementação de cafeína sobre a contribuição dos sistemas energéticos, desempenho e reativação parassimpática em simulação de luta de taekwondo. 10 atletas de taekwondo foram submetidos a duas sessões experimentais separadas por no mínimo de 48 horas entre elas. Nas duas visitas os atletas consumiram uma cápsula contendo cafeína (5 mg.kg-1 de massa corporal) ou placebo (celulose) uma hora antes da simulação da luta de taekwondo, composta por 3 rounds de 2 minutos com 1 minuto de intervalo entre os rounds. A ordem das sessões experimentais foi randomizada, duplo-cego e cruzada. Todas as simulações de luta foram filmadas para quantificar as ações técnico-táticas durante os rounds. Foram mensuradas a concentração de lactato, a percepção subjetiva de esforço (PSE) antes e após cada round,e a frequência cardíaca (FC) e a contribuição dos sistemas energéticos foi estimada durante a simulação de luta. Além disso, foram mensurados alguns índices da reativação parassimpática após o terceiro round. A concentração de lactato, a PSE, a FC e a contribuição dos sistemas energéticos foram comparados usando análise de variância de dois fatores (condição e tempo). Adicionalmente, os índices da reativação parassimpática foram comparados utilizando o teste t de Student entre as condições cafeína e placebo. Os principais resultados indicam que: a suplementação de cafeína aumentou a contribuição do sistema glicolítico em relação ao placebo. Porém, a cafeína não melhorou o desempenho ou alterou a PSE, a FC ou a contribuição dos sistemas oxidativo e ATP-CP quando comparados ao placebo. Adicionalmente, nenhum índice da reativação parassimpática foi afetado pela suplementação de cafeína. No estudo 2, o objetivo do estudo foi investigar o efeito da suplementação de bicarbonato de sódio sobre a contribuição dos sistemas energéticos durante a simulação de luta de taekwondo. Para tanto, foram avaliados 9 atletas de taekwondo, os quais foram submetidos a duas condições experimentais, separadas por um mínimo de 48 horas entre elas. Nas duas visitas os atletas ingeriram uma cápsula contendo 0,03 g.kg-1 da massa corporal de NaHCO3- ou placebo (carbonato de cálcio), 90 minutos antes da simulação de luta de taekwondo, composta por 3 rounds de 2 minutos com 1 minutos de intervalo entre os rounds. A ordem das sessões experimentais foi randomizada, duplo-cego e cruzada. Todas as simulações de luta foram filmadas para quantificar as ações técnico-táticas durante os rounds. Foram mensuradas a concentração de lactato, a percepção subjetiva de esforço antes e após cada round, a frequência cardíaca e a contribuição dos sistemas energéticos foram estimadas durante a simulação de luta. Além disso, foram mensurados alguns índices da reativação parassimpática após o terceiro round. A concentração de lactato, a PSE, a FC e a contribuição dos sistemas energéticos foram comparadas usando análise de variância de dois fatores (condição e tempo). Além disso, os índices da reativação parassimpática foram comparados utilizando o teste t de Student entre as condições NaHCO3 e placebo. Os principais resultados demonstraram que a suplementação de NaHCO3 aumentou a contribuição do sistema glicolítico e o tempo total de ataque em relação ao placebo. Porém, o NaHCO3 não alterou a FC, a PSE ou a contribuição dos sistemas oxidativo e ATP-CP durante a simulação de luta quando comparados ao placebo. Além disso, nenhum índice da reativação parassimpática foi afetado pela suplementação de NaHCO3 ou placebo / The aim of this study was to investigate the isolated effect of caffeine and sodium bicarbonate ingestion on performance, estimated energy system contribution and on post-exercise parasympathetic reactivation during a simulated taekwondo combat. Therefore, this thesis was divided in two studies: study 1 investigated the effect of caffeine, while study 2 investigated the effect of sodium bicarbonate. Thus, in study 1, the aim was to investigate the effect of caffeine supplementation on performance, estimated energy system contribution and on post-exercise parasympathetic reactivation during a taekwondo combat. Ten taekwondo athletes completed two experimental sessions separated by at least 48 hours. Athletes consumed a capsule containing either 5 mg?kg-1 body mass of caffeine or placebo (cellulose) one hour before the combat simulation (3 rounds of 2 min separated by 1-min passive recovery), in a double blinded, randomized, repeated-measures crossover design. All simulated combat was video recorded to quantify the time spend fighting in each round. Lactate concentration and rate of perceived exertion were measured before and after each round, while heart rate and the estimated contribution of oxidative, ATP-PCr and glycolytic systems were calculated during the combat simulation. Furthermore, parasympathetic reactivation after the combat simulation was evaluated. Lactate concentration, rate of perceived of exertion, heart rate, estimated system contributions and indices of time-motion were compared by two-way ANOVA (condition x time). All indices of parasympathetic reactivation were compared using a Student\'s t-test in both caffeine and placebo conditions. The main results showed that caffeine ingestion increased the estimated glycolytic system when compared to placebo condition. However, caffeine ingestion did not alter the rate of perceived exertion, heart rate, estimated oxidative and ATP-PCr contribution or improve the performance in relation to placebo condition. Furthermore, caffeine ingestion did not influence post-exercise parasympathetic reactivation following a taekwondo simulation when compared to placebo condition. In study 2, the main aim of the study was to investigate the effect of sodium bicarbonate ingestion on performance, estimated energy system contribution and on post-exercise parasympathetic reactivation during simulated taekwondo combat. Nine taekwondo athletes completed two experimental sessions separated by at least 48 hours. Athletes consumed 300 mg?kg-1 body mass of sodium bicarbonate or calcium bicarbonate (placebo) 90 minutes before the combat simulation (3 rounds of 2 min separated by 1-min passive recovery), in a double blinded, randomized, repeated-measures crossover design. All simulated combat was video recorded to quantify the time spent fighting in each round. Lactate concentration and rate of perceived exertion were measured before and after each round, while heart rate, estimated contribution of oxidative, ATP-PCr and glycolytic systems were calculated during the combat simulation. Furthermore, parasympathetic reactivation after the combat simulation was calculated. Lactate concentration, rate of perceived exertion, heart rate, estimated system contributions and indices of time-motion were compared by two-way ANOVA (condition x time). All indices of parasympathetic reactivation were compared using a Student\'s t-test. The main results showed that sodium bicarbonate ingestion increased the lactate concentration, estimated glycolytic contribution and total attack time when compared with placebo condition. However, sodium bicarbonate ingestion did not influence heart rate, rate of perceived exertion, estimated oxidative and ATP-PCr contribution during combat simulation compared to placebo. Furthermore, no indices of parasympathetic reactivation were different between sodium bicarbonate and placebo conditions