Title from first page of PDF document. Includes bibliographical references (p. 19-22).

Introdução: A hipertrigliceridemia é uma das características mais comuns na obesidade e pode ser caracterizada pela elevação dos triglicerídeos nos estados de jejum ou pós-prandial. Objetivo: Identificar os efeitos de uma sessão aguda de exercício aeróbio na lipemia pós-prandial em adultos obesos de acordo com o polimorfismo -3826 A/G no gene da UCP1. Métodos: Trinta e seis adultos jovens de ambos os sexos foram separados para o grupo Eutrófico AA (EAA, n=10), Eutrófico AG (EAG, n=8), Obeso AA (OAA, n=8) e Obeso AG (OAG, n=10). Após sessões de genotipagem e teste máximo, os triglicerídeos foram determinados em jejum de doze horas, duas, três, quatro e seis horas após ingestão de refeição rica em gordura em duas oportunidades, em repouso e exercício. Os sujeitos vieram ao laboratório para a sessão exercício onde pedalaram por 45 minutos a 60% do seu VO2pico pré determinado. Resultados: o exercício aeróbio foi capaz de modificar a trigliceridemia pós-prandial dos grupos EAA (p=0,01), EAG (p=0,03) e OAA (p=0,000), entretanto, para o grupo OAG (p=0,15) o exercício não causou efeito. Quando comparamos a ASC para os quatro grupos observou-se um efeito no fator tratamento e a diferença foi encontrada apenas nos OAA (p=0,01). Também foi encontrado um efeito no fator grupo, EAA com EAG, OAA com OAG não apresentaram diferenças, entretanto, quando comparamos EAA com OAA (p=0,000) e EAG com OAG (p=0,000) encontramos diferenças tanto para o tratamento controle quanto para o exercício. Conclusão: A trigliceridemia pós-prandial em adultos jovens sedentários de ambos os sexos foi modificada pelo exercício agudo nos grupos EAA, EAG, OAA, porém, para o grupo OAG o mesmo não causou efeito. / Introduction: Hypertriglyceridemia is a common feature in obesity and can be characterized by elevated triglycerides in fasting state or postprandial. Purpose: to identify the effects of an acute bout of aerobic exercise on postprandial lipemia in obese adults according to the polymorphism -3826 A/G gene UCP1. Methods: Thirty-six young adults of both sexes were separated for Eutrophic group AA (EAA, n=10), Eutrophic AG (EAG, n=8), Obese AA (OAA, n=8) and Obese AG (OAG, n=10). After genotyping and testing sessions maximum. Triglycerides were determined after fasting for twelve hours, two, three, four and six hours after ingestion of high-fat meal on two occasions, at rest and exercise. The subjects came to the laboratory for the exercise session where they cycled for 45 minutes at 60% of their VO2peak predetermined. Results: The aerobic exercise was able to modify the postprandial triglyceridemia EAA group (p=0,01), EAG (p=0,03) and OAA (p=0,000), however, for the exercise caused no effect group OAG (p=0,15). When comparing the AUC for the four groups there was an effect on the treatment factor and the difference was found only in the OAA (p=0,01). They also found an effect in factor group, EAA with EAG, OAA with OAG did not differ, however, when compared EAA with OAA (p=0,000) and EAG with OAG (p=0,000) differences were found for both treatment and control for the year. Conclusion: The postprandial triglyceridemia in sedentary young adults of both sexes was modified by acute exercise in groups EAA, EAG, OAA, however, for the OAG group did not cause the same effect.

Submitted by Angelica Miki Stein null (angelica_stein@yahoo.com.br) on 2018-02-15T15:11:26Z No. of bitstreams: 1 Tese completa - Stein AM_DR .pdf: 7740796 bytes, checksum: ed16030624fe5ab04287eb42146f66b8 (MD5) / Approved for entry into archive by Ana Paula Santulo Custódio de Medeiros null (asantulo@rc.unesp.br) on 2018-02-15T18:42:06Z (GMT) No. of bitstreams: 1 stein_am_dr_rcla.pdf: 7526722 bytes, checksum: 99f7c1d945c7338609585fc2899edee0 (MD5) / Made available in DSpace on 2018-02-15T18:42:06Z (GMT). No. of bitstreams: 1 stein_am_dr_rcla.pdf: 7526722 bytes, checksum: 99f7c1d945c7338609585fc2899edee0 (MD5) Previous issue date: 2017-12-18 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Para auxiliar o tratamento da doença de Alzheimer (DA), existem alternativas não farmacológicas, como o exercício físico. Efeitos do exercício físico em supostos mecanismos como o fator de crescimento semelhante a insulina (IGF-1), tem sido associado a melhoras encefálica, relacionadas à melhora de desempenho cognitivo, neurogênese, depuração do peptídeo beta-amilóide e redução da tau fosforilada. Dessa forma, o objetivo geral desta tese foi verificar a relação entre exercício físico, níveis circulantes de IGF-1 e DA. A tese foi estruturada em 6 capítulos, sendo Capítulo 1: descrição dos objetivos, revisão de literatura e delineamento do estudo; Capítulo 2: artigo de revisão sistemática sobre os estudos que investigaram o efeito do exercício físico nas funções cognitivas e IGF-1 circulante em idosos; Capítulo 3: estudo que teve como objetivo comparar a resposta ao exercício aeróbio agudo nos níveis de IGF-1 circulante de idosos cognitivamente preservados e idosos com DA; Capítulo 4: o objetivo deste estudo foi verificar o efeito do treinamento aeróbio nas funções cognitivas e níveis de IGF-1 em idosos com DA; Capítulo 5: estudo que teve como objetivo comparar a resposta ao exercício aeróbio agudo na cognição e atividade encefálica em camundongos selvagens, pré sintomáticos da DA e com deficiência de IGF-1; Capítulo 6: considerações gerais e conclusões da tese. No Capítulo 2 foram encontrados 7 estudos que verificaram o efeito do exercício nos níveis de IGF-1 e na função cognitiva de idosos em diferentes condições, como idosos cognitivamente preservados, idosos com comprometimento cognitivo leve e idosos pré-diabéticos. Os resultados apontaram que não há consenso entre melhor tipo de exercício, intensidade, frequência e duração para provocar melhora das funções cognitivas e regulação de IGF-1 circulante. O capítulo 3 traz um estudo em que participaram 74 idosos: 40 idosos cognitivamente preservados e 34 idosos com doença de Alzheimer. Todos os participantes responderam a uma avaliação cognitiva e foram submetidos a um teste incremental em esteira ergométrica. Sobretudo, foi demonstrado que idosos com DA e idosos cognitivamente preservados responderam ao exercício aeróbio agudo de maneira diferente: idosos com DA tiveram aumento dos níveis de IGF-1 e idosos cognitivamente preservados tiveram manutenção nestes mesmos níveis. No Capítulo 4, 16 idosos com DA compuseram o Grupo Controle (GC) e 18 idosos com DA, o Grupo Treinamento (GT). O GT participou de um protocolo de treinamento aeróbio, realizado a 80% da frequência cardíaca, com duração de 25-40 min/sessão, três vezes semanais, com duração de 12 semanas. Após o período experimental, não foram identificadas diferenças significativas entre grupos e momentos para as funções cognitivas e níveis de IGF-1. Porém, resultados clínicos na cognição e no controle de quadros de insulino-resistência foram observados no GT. No Capítulo 5 foi verificado camundongos selvagens tiveram aumento significativo na banda theta e desempenho cognitivo superior quando comparados aos outros grupos de animais. Por último, o Capítulo 6 traz as considerações gerais e conclusões da tese: não existe um protocolo único capaz de modificar os níveis de IGF-1 e provocar melhora cognitiva; idosos cognitivamente preservados e idosos com DA respondem de maneira diferente ao exercício aeróbio agudo quanto aos níveis de IGF-1; o treinamento aeróbio adotado não foi efetivo para melhora cognitiva, nem para modificações nos níveis de IGF-1; camundongos selvagens, pré-sintomáticos da DA e com deficiência de IGF-1 respondem de maneira diferente ao exercício aeróbio agudo na atividade encefálica, sendo que o exercício agudo se mostrou efetivo no desempenho cognitivo. / To help the treatment of Alzheimer's disease (AD), there are non-pharmacological alternatives, such as physical exercise. Possible effects of physical exercise on putative mechanisms, such as the insulin-like growth factor-1 (IGF-1), have been associated with improvements on brain health, related to cognition, neurogenesis, clearance of the protein beta-amyloid and p-tau. Thus, the objective of this thesis was to verify the relation among physical exercise, circulating IGF-1 and AD. The thesis was structured in 6 chapters - Chapter 1: description of the objectives, literature review and design of the study; Chapter 2: systematic review manuscript about studies that investigated the physical exercise effects on cognitive functions and circulating IGF-1 in elderlies; Chapter 3: the objective was to compare the response to aerobic acute exercise in circulating IGF-1 levels in cognitively preserved elderly and elderly with AD; Chapter 4: the objective was to verify the aerobic training effect on cognitive functions and IGF-1 levels in elderly with AD; Chapter 5: the objective was to compare the response to acute aerobic exercise on cognition and brain activity in wild mice, pre symptomatic AD mice and IGF-1 deficiency mice; Chapter 6: general considerations and conclusions. In the Chapter 2, 7 papers verified the exercise effect on IGF-1 levels and cognitive function in elderlies with different conditions, as cognitively preserved elderly, mild cognitive impairment and pre diabetes was found. The results pointed that there was no consensus about recommendation of best type of exercise, intensity, frequency and duration to induce improvement on cognition and circulating IGF-1 regulation. The Chapter 3 brings a study with transversal profile, with 74 participants: 40 cognitively preserved elderly and 34 elderly with AD. All participants responded to cognitive evaluation and they were submitted to a incremental test in ergometric treadmill. Mainly, elderly with AD and cognitively preserved elderlies responded to acute aerobic exercise in different ways. Elderly with AD had an increase on IGF-1 levels whereas cognitively preserved elderlies had a maintaining in this same levels. In the Chapter 4 in order to verify the training effect on cognitive functions and IGF-1, 16 elderlies with AD participated in Control Group (CG) and 18 elderlies with AD, in Training Group (TG). The TG participated in an aerobic training protocol, 75% of heart rate, 4 km/h, 25-40 min/session, 3 times weekly, during 12 weeks. After the experimental period, significant differences between groups and moments for cognitive functions and IGF-1 levels were not identified. However, interesting clinical results was observed in cognition and insulin-resistance control of TG. In Chapter 5, wild mice had a significant increase on theta rhythm and better cognitive performance when they were compared to another animal groups. Finally, the Chapter 6 brings us general considerations and conclusions of the thesis: there is not only one protocol capable to modify IGF-1 levels and induce cognition improvement; cognitively preserved elderly and elderly with AD responded differently to acute aerobic exercise in IGF-1 levels; the training protocol adopted in this study was not effective neither to improve cognition, nor to modified IGF-1 levels in elderlies with AD; wild mice, AD pre symptomatic mice and IGF-1 deficiency mice responded different to acute aerobic exercise in brain activity, considering acute exercise effective on cognitive performance. / FAPESP: 2013/19729-0 / CAPES: PDSE 99999.010743/2014-06

Introdução: A hipertrigliceridemia é uma das características mais comuns na obesidade e pode ser caracterizada pela elevação dos triglicerídeos nos estados de jejum ou pós-prandial. Objetivo: Identificar os efeitos de uma sessão aguda de exercício aeróbio na lipemia pós-prandial em adultos obesos de acordo com o polimorfismo -3826 A/G no gene da UCP1. Métodos: Trinta e seis adultos jovens de ambos os sexos foram separados para o grupo Eutrófico AA (EAA, n=10), Eutrófico AG (EAG, n=8), Obeso AA (OAA, n=8) e Obeso AG (OAG, n=10). Após sessões de genotipagem e teste máximo, os triglicerídeos foram determinados em jejum de doze horas, duas, três, quatro e seis horas após ingestão de refeição rica em gordura em duas oportunidades, em repouso e exercício. Os sujeitos vieram ao laboratório para a sessão exercício onde pedalaram por 45 minutos a 60% do seu VO2pico pré determinado. Resultados: o exercício aeróbio foi capaz de modificar a trigliceridemia pós-prandial dos grupos EAA (p=0,01), EAG (p=0,03) e OAA (p=0,000), entretanto, para o grupo OAG (p=0,15) o exercício não causou efeito. Quando comparamos a ASC para os quatro grupos observou-se um efeito no fator tratamento e a diferença foi encontrada apenas nos OAA (p=0,01). Também foi encontrado um efeito no fator grupo, EAA com EAG, OAA com OAG não apresentaram diferenças, entretanto, quando comparamos EAA com OAA (p=0,000) e EAG com OAG (p=0,000) encontramos diferenças tanto para o tratamento controle quanto para o exercício. Conclusão: A trigliceridemia pós-prandial em adultos jovens sedentários de ambos os sexos foi modificada pelo exercício agudo nos grupos EAA, EAG, OAA, porém, para o grupo OAG o mesmo não causou efeito. / Introduction: Hypertriglyceridemia is a common feature in obesity and can be characterized by elevated triglycerides in fasting state or postprandial. Purpose: to identify the effects of an acute bout of aerobic exercise on postprandial lipemia in obese adults according to the polymorphism -3826 A/G gene UCP1. Methods: Thirty-six young adults of both sexes were separated for Eutrophic group AA (EAA, n=10), Eutrophic AG (EAG, n=8), Obese AA (OAA, n=8) and Obese AG (OAG, n=10). After genotyping and testing sessions maximum. Triglycerides were determined after fasting for twelve hours, two, three, four and six hours after ingestion of high-fat meal on two occasions, at rest and exercise. The subjects came to the laboratory for the exercise session where they cycled for 45 minutes at 60% of their VO2peak predetermined. Results: The aerobic exercise was able to modify the postprandial triglyceridemia EAA group (p=0,01), EAG (p=0,03) and OAA (p=0,000), however, for the exercise caused no effect group OAG (p=0,15). When comparing the AUC for the four groups there was an effect on the treatment factor and the difference was found only in the OAA (p=0,01). They also found an effect in factor group, EAA with EAG, OAA with OAG did not differ, however, when compared EAA with OAA (p=0,000) and EAG with OAG (p=0,000) differences were found for both treatment and control for the year. Conclusion: The postprandial triglyceridemia in sedentary young adults of both sexes was modified by acute exercise in groups EAA, EAG, OAA, however, for the OAG group did not cause the same effect.

Introdução: A hipertrigliceridemia é uma das características mais comuns na obesidade e pode ser caracterizada pela elevação dos triglicerídeos nos estados de jejum ou pós-prandial. Objetivo: Identificar os efeitos de uma sessão aguda de exercício aeróbio na lipemia pós-prandial em adultos obesos de acordo com o polimorfismo -3826 A/G no gene da UCP1. Métodos: Trinta e seis adultos jovens de ambos os sexos foram separados para o grupo Eutrófico AA (EAA, n=10), Eutrófico AG (EAG, n=8), Obeso AA (OAA, n=8) e Obeso AG (OAG, n=10). Após sessões de genotipagem e teste máximo, os triglicerídeos foram determinados em jejum de doze horas, duas, três, quatro e seis horas após ingestão de refeição rica em gordura em duas oportunidades, em repouso e exercício. Os sujeitos vieram ao laboratório para a sessão exercício onde pedalaram por 45 minutos a 60% do seu VO2pico pré determinado. Resultados: o exercício aeróbio foi capaz de modificar a trigliceridemia pós-prandial dos grupos EAA (p=0,01), EAG (p=0,03) e OAA (p=0,000), entretanto, para o grupo OAG (p=0,15) o exercício não causou efeito. Quando comparamos a ASC para os quatro grupos observou-se um efeito no fator tratamento e a diferença foi encontrada apenas nos OAA (p=0,01). Também foi encontrado um efeito no fator grupo, EAA com EAG, OAA com OAG não apresentaram diferenças, entretanto, quando comparamos EAA com OAA (p=0,000) e EAG com OAG (p=0,000) encontramos diferenças tanto para o tratamento controle quanto para o exercício. Conclusão: A trigliceridemia pós-prandial em adultos jovens sedentários de ambos os sexos foi modificada pelo exercício agudo nos grupos EAA, EAG, OAA, porém, para o grupo OAG o mesmo não causou efeito. / Introduction: Hypertriglyceridemia is a common feature in obesity and can be characterized by elevated triglycerides in fasting state or postprandial. Purpose: to identify the effects of an acute bout of aerobic exercise on postprandial lipemia in obese adults according to the polymorphism -3826 A/G gene UCP1. Methods: Thirty-six young adults of both sexes were separated for Eutrophic group AA (EAA, n=10), Eutrophic AG (EAG, n=8), Obese AA (OAA, n=8) and Obese AG (OAG, n=10). After genotyping and testing sessions maximum. Triglycerides were determined after fasting for twelve hours, two, three, four and six hours after ingestion of high-fat meal on two occasions, at rest and exercise. The subjects came to the laboratory for the exercise session where they cycled for 45 minutes at 60% of their VO2peak predetermined. Results: The aerobic exercise was able to modify the postprandial triglyceridemia EAA group (p=0,01), EAG (p=0,03) and OAA (p=0,000), however, for the exercise caused no effect group OAG (p=0,15). When comparing the AUC for the four groups there was an effect on the treatment factor and the difference was found only in the OAA (p=0,01). They also found an effect in factor group, EAA with EAG, OAA with OAG did not differ, however, when compared EAA with OAA (p=0,000) and EAG with OAG (p=0,000) differences were found for both treatment and control for the year. Conclusion: The postprandial triglyceridemia in sedentary young adults of both sexes was modified by acute exercise in groups EAA, EAG, OAA, however, for the OAG group did not cause the same effect.

Estudos recentes têm associado à prática de exercício físico de alta intensidade e de forma inabitual a alterações musculares que incluem lesões estruturais das miofibras. Nessa perspectiva, a suplementação de aminoácidos de cadeia ramificada (BCAA) destaca-se como uma estratégia eficaz no controle do dano celular e na promoção da recuperação muscular. Uma vez que, dentre os BCAA, a leucina é o que apresenta maior influência sobre a regulação de mecanismos anabólicos que incluem o estímulo ao aumento da taxa de tradução de RNAm mediado pela proteína quinase mTOR, se especula quais os possíveis efeitos da sua suplementação isolada em um modelo de exercício físico extenuante e inabitual. Buscamos então, com o presente estudo, avaliar o efeito da suplementação com leucina sobre as concentrações séricas de creatina quinase - marcadores de lesão muscular - e sobre a expressão e fosforilação das proteínas mTOR, 4E-BP1, S6K1, IKK, IkB-α, NF-κB - componentes de vias envolvidas na síntese de proteínas e da inflamação - no músculo esquelético de ratos adultos não treinados, submetidos a uma sessão de exercício até a exaustão. Para tanto, 48 ratos machos adultos da linhagem Sprague-Dawley foram distribuídos em 10 grupos, sendo que T3L, T48L E T72L receberam suplementação com leucina [leucina (135 mg/100 g) e T3A, T48A e T72A receberam uma mistura de aminoácidos não essenciais (135 mg/100 g)] ao final de uma sessão de exercício físico agudo até a exaustão; T3E, T48E e T72E - não receberam suplementação e foram submetidos ao protocolo de exercício; o grupo controle não recebeu suplementação e não foi submetido ao protocolo de exercício. Em seguida os animais foram eutanasiados 3, 48 e 72 horas após o termino do exercício para análise dos marcadores investigados. Entre os parâmetros avaliados houve diferença significativa na atividade da creatina quinase entre os grupos TL3 e TL4. No entanto os marcadores biomoleculares não apontaram diferenças entre os grupos. No entanto a fosforilação do NF- Kb da fração nuclear demonstrou uma tendência a ser menor nos grupos suplementados com leucina e o mesmo acontece com a MCP-1 (proteína quimioatraente de monócitos). Visto isso, podemos concluir que, em nossas condições experimentais, as vias de sinalização estudadas estavam envolvidas na diminuição da atividade da creatina quinase, porém, nossos resultados apontam que a suplementação com leucina pode estar envolvida em mecanismos que atenuem o dano celular após o exercício agudo em ratos não treinados. / Recent studies have associated infrequent exercise of high intensity to muscle changes that include structural lesions in myofibres. The supplementation of branched chain aminoacids (BCAA) stands out as an effective strategy in controlling the cell damage and promoting muscle recovery. As leucine is the BCAA exerting more influence on the regulation of anabolic mechanisms that include stimulating the increase of mRNA translation rate mediated by the protein kinase mTOR, it is speculated the potencial effects of leucine supplementation alone in a model of strenuous and infrequent exercise. In the present study, we evaluate the effect of leucine supplementation on serum levels of creatine kinase - marker of muscle damage - and on the expression and phosphorylation of proteins mTOR, 4E-BP1, S6K1, IKK, IkB-α, NF-κB - components of pathways involved in protein synthesis and inflammation - in the skeletal muscle of untrained adult rats, after a single acute bout of exercise to exhaustion. Forty eight adult male Sprague-Dawley rats were divided into 10 groups: T3L, T48L and T72L groups were given leucine supplementation [leucine (135 mg/100 g), and T3A, T48A and T72A groups were given a mix of non-essential aminoacids (135 mg/100 g)] at the end of the acute bout of exercise to exhaustion; T3E, T48E and T72E groups did not receive supplementation and underwent the exercise protocol; control group was not given supplementation nor exercise protocol. The animals were killed 3, 48 and 72 hours after the end of exercise to analyze the markers under study. Among the parameters assessed, there was a significant difference in the activity of creatine kinase between groups TL3 and TL4. However, no differences were seen in the biomolecular markers between groups. Nevertheless, the nuclear fraction of NF- Kb phosphorylation tended to be lower in the groups supplemented with leucine and the same was seen with MCP-1 (monocyte chemoattractant protein). Taken together, we conclude that the signalling pathways studied, in our experimental condition, do not seem to be involved in the reduced activity of creatine kinase; conversely, our results indicate that leucine supplementation may be involved in mechanisms attenuating cellular damage after a single acute bout of exercise in untrained rats.

Although, it is well established that regular exercise has a positive effect on various domains of cognitive functions, effects of a single session (acute) exercise on cognitive functions of an young adult is under debate. While a numbers of research have found positive associations between acute exercise and cognitive performance, multiple research have found no effect of acute exercise on the cognitive functions. There are also evidences that suggest that acute exercise reduces brain function of healthy young adults. This thesis took on a meta-analytical approach to determine the effect of a single session exercise on the cognitive functions of healthy young adults, and metaregression analyses were performed to identify the moderators that may influence the effect of acute exercise on cognitive functions of healthy young adults. After a comprehensive electronic search 59 experimental studies were found to be eligible for inclusions based on the pre-specified criteria. Results indicated that acute exercise has a small but significant effect on the cognitive functions of healthy young adults. However, larger effects are possible for particular cognitive outcomes (reaction time), when specific exercise parameters are used (5 minutes of exercise duration, moderate intensity exercise), and when specific assessment task is used (visual span board task, and serial subtraction of 7). The overall findings of this study is consistent with previous research. However, more research is needed to get a clear understanding of the acute exercise effect moderators.

The primary purpose of this study was to determine if changes in physical self-efficacy, physical self-perceptions, and affect (including enjoyment) are mechanisms by which a single bout of exercise improves state body image. A secondary purpose was to identify how long exercise-related improvements in state body image are sustained post-exercise. Sixty women with body image dissatisfaction were randomized to either an exercise or control condition. Participants in the exercise condition completed a 30 minute moderate-to-vigorous intensity workout on a stationary bike. Women in the control condition read for the same duration. Before and immediately, 10-minutes and 20-minutes after (post-0, post-10, post-20) the exercise/control manipulations, participants completed measures of state body image, aerobic self-efficacy, physical self-perceptions and affect (including enjoyment). PROCESS macro was used to test mediation models, and a repeated measures mixed ANCOVA, followed by a univariate ANCOVA was used to test how long state body image improvements were sustained. There was a significant indirect effect of increases in strength self-perceptions on state body image improvements from pre- to post-0 (95% C.I. =.07 - .52, κ2=.16, abps=.31), post-10 (95% C.I.=.05 - .50, κ2=.16, abps=.30) and post-20 minutes (95% C.I. = .10 - .55, κ2 =.16, abps =.33), as well as a significant indirect effect of decreases in tiredness (i.e., increases in the energetic arousal dimension) on state body image improvements from pre- to post-10 (95% C.I. =.22 – 1.14, κ2=.30, abps=.77). Exercise-related state body image improvements were sustained 20 minutes after exercise. The present findings suggest that a bout of exercise improves state body image through increases in strength self-perceptions and energetic arousal and these effects lasted up to 20 minutes. This is the first study to design and empirically test a model to account for the effects of exercise on state body image, and provides important theoretical and practical implications. / Thesis / Master of Science (MSc)

No description available.

Elevated postprandial triacylglycerol concentrations ([TAG]) are associated with the development and progression of atherosclerosis, and are established as an independent risk factor for future cardiovascular disease. Considering the majority of the daytime is spent in a postprandial state typically, and the paediatric origins of atherosclerosis are well established, lifestyle interventions including manipulations of exercise energy expenditure and dietary energy intake should be initiated early in life. Therefore, this thesis aimed to investigate the postprandial metabolic responses to different exercise and energy intake manipulations in boys and girls, with concentrations of circulating TAG representing the primary outcome of interest. To achieve this, a total of 60 healthy 11 to 13 year old boys and girls were recruited into five experimental studies. The first experimental study (Chapter 4) demonstrated that a single session of high-intensity interval running (HIIR) involving 10 x 1 min intervals at 100% maximal aerobic speed (MAS) resulted in a moderate reduction in postprandial plasma [TAG] in 11 to 12 year old boys. In the second experimental study (Chapter 5), immediate replacement of the moderate-intensity exercise-induced energy deficit negated the reduction in postprandial plasma [TAG] in 11 to 13 year old boys. Furthermore, an exercise-induced energy deficit was required to promote an increase in whole-body fat oxidation. The importance of the associated energy deficit was explored further in Chapter 6, which demonstrated that a moderate-intensity exercise-induced energy deficit elicited a greater reduction in postprandial plasma [TAG] than an isoenergetic diet-induced energy deficit in 11 to 13 year old girls (21% vs. 10% respectively). Chapter 7 compared the effect of 10 x 1 min interval runs at 100% MAS (HIIR) and 5 x 1 min interval runs at 100% MAS combined with a mild reduction in habitual energy intake by 0.82 MJ (195 kcal; HIIR-ER) on postprandial metabolism in 11 to 13 year old girls. Acute manipulations of low volume HIIR and ER reduced postprandial plasma [TAG] and increased resting whole-body fat oxidation, with the magnitude of effect marginally, although not meaningfully, greater following HIIR than HIIR-ER. The final experimental chapter (Chapter 8) compared directly healthy 11 to 13 year old boys and girls postprandial TAG responses to acute HIIR. Although postprandial plasma [TAG] was substantially lower in boys compared with girls, the magnitude of reduction following HIIR was similar between the sexes (11% vs. 10% respectively). Collectively, these studies demonstrate the efficacy of acute moderate- and high-intensity exercise, and to a lesser extent energy-intake restriction, to reduce postprandial plasma [TAG] and increase resting whole-body fat oxidation in boys and girls. Furthermore, the beneficial effect of exercise on postprandial metabolism appears dependent on the maintenance of the associated energy deficit. These lifestyle interventions have the potential to provide a practical, effective and engaging stimulus to promote a healthier cardiovascular risk profile in early adolescence.