Syfte och frågeställningar Syftet med studien var att undersöka för elitorienterare resultaten vid och korrelationen mellan ett så kallat 5 minuters pyramidtest (5MPT) och ett maximalt test för bestämning av maximalt syreupptag (VO2max) på rullband. Frågorna vi ställde oss var: Vilken korrelation föreligger mellan 5MPT och ett bestämt VO2max på rullband hos elitorienterare? Hur ser en jämförelse ut mellan uppmätt samt beräknat VO2max? Vilken är reliabiliteten för 5MPT? Hur ser ekvationen ut för att beskriva sambandet mellan dessa två olika maxtester? Metod I valideringsstudien deltog 16 elitorienterare (6 kvinnor och 10 män) i åldrarna 17 till 37 år. De två testerna som genomfördes var 5MPT och bestämning av VO2max på rullband. 5MPT är ett skytteltest som är fem minuter långt, där testpersonen (tp) tar sig fram och tillbaka mellan två stolpar (sträcka 5.5 m) där en vertikal trappa (formad likt en pyramid) passeras under varje vända. Antalet vändor, skattad ansträngning samt hjärtfrekvens (HF) registrerades. Utvecklad power (effekt) erhölls genom produkten av vikt, gravitation, antal vändor, höjd på högsta plinten (0,62 m) dividerat med total duration i 5MPT. Testet för att bestämma VO2max utfördes med löpning på ett motordrivet rullband. Under den första minuten av testet sprang tp på en hastighet av 8km/h (kvinnor) respektive10km/h (män) utan lutning. För varje minut ökades hastigheten med 1km/h. Lutningen höjdes med en grad efter minut ett och därefter med 0,5 grader/minut. Testet pågick till dess tp nått sin VO2max. Var 15:e sekund registrerades tp:s HF, VO2 (l/min), VCO2 (l/min), VO2 (ml/kg/min) och respiratorisk kvot (RER) med hjälp av ett datoriserat syreupptagningssystem. Resultat Korrelationen var signifikant och hög (r = 0,89, p<0,0001) mellan utvecklad power på 5MPT och VO2max (l/min) och även mellan antalet vändor på 5MPT och VO2max (l/min) (r = 0,89, p<0,0001) på detta material av elitorienterare. Följande formler, baserade på resultaten från elitorienterarna, kan användas för att predicera VO2max efter genomfört 5MPT: VO2max  (l/min) = (5MPTPOWER – 50,914) / 25,795 VO2max (l/min) = (5MPTVÄNDOR – 74,447) / 9,7668 Slutsats 5MPT uppvisar en stark korrelation med bestämd VO2max sett till power och/eller antalet genomförda vändor. Beräkningsformler för prediktion av VO2max har varit möjligt att beskriva. Se resultatdelen för andra resultat och samband mellan 5MPT och VO2max. / Abstract Aim The aim of this study was to investigate for elite orienteers the results in and the correlation between a so called 5-minutes-pyramid test (5MPT) and a specific maximum oxygen uptake test (VO2max) on a treadmill. The questions we asked ourselves were: Which correlation exists between 5MPT and a specific VO2max on the treadmill for elite orienteers? How would a comparison look like between measured and estimated VO2max? What is the reliability for the 5MPT? How would an equation look like that describe the correlation above? Method In the validity the study 16 elite orienteers (6 women and 10 men) aged 17 to 37 years participated. The two tests that have been carried out were the 5MPT and determined VO2max during running on a treadmill. The 5MPT is a 5-minute-shuttle test, in which the participant moves back and forth in a short interval (5.5 m) over boxes (highest height: 0.62) formed like a pyramid. Power in the pyramid test (5MPTPOWER) was calculated as the product of numbers of laps, body weight, gravity and highest box level divided by time. To determine VO2max the method running on a treadmill was performed. During the first minute the running speed was 8km/h (women)/10 km/h (men) without elevation. Each minute the velocity increased with 1 km/h. The elevation increased with 1 degree after the first minute and thereafter with 0,5 degrees/minute.  The test was finished when the participant had reached her VO2max. Every 15 second the participants heart rate, VO2 (l/min), VCO2 (l/min), VO2 (ml/kg/min) and RER, was registered by means of an online system. Results The correlation between the developed power of the 5MPT and measured VO2max (l/min) was high (r = 0.89, p<0,0001) and also between the number of laps in the 5MPT and measured VO2max (l/min) (r = 0.89, p < 0,0001). The following formulas can be used to predict VO2max after completed 5MPT: VO2max  (l/min) = (5MPTPOWER – 50,914) / 25,795 VO2max (l/min) = (5MPTLAPS – 74,447) / 9,7668 Conclusions 5MPT show a strong correlation with VO2max determined in terms of power and/or the number of completed laps. Calculated formulas for prediction of VO2max have been possible to describe. See results section for other results and relationships between 5MPT and VO2max. / Maximal Aerobic Power versus Performance in Two Aerobic Endurance Tests among Young and Old Adults.Andersson E, Lundahl N, Wecke L, Lindblom I, Nilsson, J.

Made available in DSpace on 2016-06-02T20:18:13Z (GMT). No. of bitstreams: 1 3132.pdf: 3107997 bytes, checksum: 1b931ab55a545210b8e98eae0eee3ce1 (MD5) Previous issue date: 2010-05-10 / Universidade Federal de Sao Carlos / This work is composed of three distinct studies. In the first one, we compared the muscle coactivation of tibialis anterior (TA) and gastrocunemius medialis (GM) during quiet stance and the also during the stance phase of gait in hemiparetic subjects (hemiparetic group, HG, n=12) and in subjects with no neurologic injuries (control group, CG, n=10). We evaluated the TA and GM electromyographic signal and calculated their overlapping ratio (OR). We concluded that these individuals do not present significant coactivation alterations in the stance phase of gait, but in quiet stance they seem to use the coactivation of the non-paretic limb to maintain postural stability. In the second study we investigated the effects of the association of treadmill training with body weight support (TTBWS) associated with strength training of ankle muscles on the motor control in chronic hemiparetic subjects. Fifteen volunteers were distributed into 2 treatment groups: 1) TTBWS (G1; n=7); and 2) TTBWS associated with resistance training for dorsi and plantar flexors (G2; n=8). We evaluated muscle performance of plantar flexion and dorsiflexion in an isokinetic dynamometer through peak torque (PT), total work (TW) and acceleration time (AT) at the speeds of 60°/s and 120°/s. For gait analysis we assessed the ground reaction forces (GRF). There was an increase in PT and TT of plantar flexion at 60°/s in the paretic side, and an increase in the positive peak of the anterior-posterior GRF component in both sides of G2. We suggested that the proposed intervention leads to improvements in the components related to propulsion of gait. In the third study, we evaluated the effect of the robot assisted gait training (RAGT) in children with spastic diplegia. Twenty children (12 male, 5-13 years old) were evaluated for functional outcomes and spatial-temporal patterns of gait before, after and 3 months after the end of the intervention. Comparisons revealed significant improvements on functional outcomes and in gait mechanics. We concluded that RAGT promotes better gait patterns, and that the learning of this new task is retained even after the end of the intervention. / Este trabalho é composto por três estudos distintos. Inicialmente comparamos a coativação dos músculos tibial anterior (TA) e gastrocnêmio medial (GM) em postura ortostática e durante a fase de apoio da marcha de indivíduos hemiparéticos (grupo hemiparético, GH; n = 12) e de indivíduos sem lesões neurológicas (grupo controle, GC; n = 10). Avaliamos o sinal eletromiográfico do TA e do GM e calculamos a taxa de sobreposição dos mesmos (ICoa). Em atividade estática observamos maior ICoa no membro não parético do GH quando comparado com o membro dominante do GC. Concluímos que hemiparéticos não apresentam alterações significativas da coativação na fase de apoio da marcha, mas em atividade estática parecem utilizar o aumento da coativação do lado não parético para a manutenção da estabilidade. No segundo estudo investigamos os efeitos da associação do treino de marcha em esteira com suporte parcial do peso corporal (TMESPP) ao treinamento de força para a musculatura do tornozelo sobre o controle motor em indivíduos hemiparéticos crônicos. Quinze voluntários foram distribuídos em 2 grupos de tratamento: 1) TMESPP (G1; n=7) e 2) TMESPP associado ao fortalecimento da musculatura do tornozelo (G2; n=8). Avaliamos o desempenho muscular nos movimentos de plantiflexão e dorsiflexão em dinamômetro isocinético nas velocidades de 60°/s e 120°/s, através dos valores de pico de torque (PT), trabalho total (TT) e tempo de aceleração (TA). Para avaliação da marcha analisamos as forças de reação do solo (FRS). Houve aumento do PT e do TT da plantiflexão a 60°/s do lado parético, e aumento dos picos positivos do componente ântero-posterior das FRS em ambos os lados do G2. Sugerimos que a intervenção proposta provoca melhora nos componentes da propulsão da marcha. O terceiro estudo avaliou o efeito do treino de marcha assistido por robô (TMAR) em 20 crianças com diparesia espástica (12 sexo masculino, 5-13 anos). Avaliamos medidas funcionais e padrões espaço-temporais da marcha antes, após e três meses depois do término da intervenção. As comparações revelaram melhora significativa nas medidas funcionais e na mecânica da marcha. Concluímos que o TMAR promove melhoras nos padrões da marcha, e que a aprendizagem dessa nova tarefa é retida mesmo após a interrupção do treino.

Made available in DSpace on 2016-06-02T19:02:40Z (GMT). No. of bitstreams: 1 3747.pdf: 6525981 bytes, checksum: 7091d3e5dff2ebc0abdf60c75dabc78a (MD5) Previous issue date: 2011-06-29 / Financiadora de Estudos e Projetos / The objective of this study was to investigate the effects of infrared-LED illumination associated with treadmill training. Forty five postmenopausal women (50-60 years old) participated in this study. They were randomly separated into 3 groups: (i) the LED group, with phototherapy during the treadmill training; (ii) the exercise group, carried out only treadmill training and (iii) the sedentary group, with neither phototherapy nor physical exercise. The treadmill training consisted of walking twice a week for 45 min at intensities between 85% to 90% maximal heart rate during 1 year. The irradiation parameters were 100mW, 40 mW/cm2, 108 J/cm2 and the treatment time of 45 min. The treatment was evaluated through maximal effort testing using treadmill, isokinetic dynamometry, anthropometry, body composition, blood exams, quality of life, bone mineral density, thermography, photographic documentation and nutritional aspects. The two-way ANOVA and one-way ANOVA with Bonferroni adjustments were used for the statistical analysis. The significance level was set at p<0.05. The most important results for the LED group were: improving the maximal exercise tolerance (&#916;Tlim=432±180seg, p=0.001 e; &#916;METs=4.2±1, p=0.01), increasing the muscle power (&#916;=21±6W, p=0.04) and reducing fatigue (&#916;=-7±4%, p=0.006). There were no significant differences in the body composition (p&#8805;0.05), but a qualitative difference of the skin was seen concerning the treatment of cellulite. There were reducted cholesterol levels (&#916;total cholesterol=-42±23 mg/dl, p=0.0003 and &#916;LDL=-35±20 mg/dl, p=0.001), as well as an increase of the quality of life (from 82±17 to 89±17, p=0.04). There were no significant differences noted concerning the bone mass loss (p&#8805;0.05). The cutaneous temperature increased during the exercise with the LEDs (from 33.5±0.8°C to 34.6±0.9°C, p=0.03). The results showed that the LED-illumination (850nm) improved physical performance and showed clinical benefits for the group of women investigated. Phototherapy associated with treadmill training can therefore be potentially used for sports, rehabilitation and aesthetics protocols to achieve certain positive results. / O objetivo deste estudo foi investigar os efeitos da iluminação-LED infravermelha durante o treinamento em esteira ergométrica. Participaram deste estudo 45 mulheres na pós-menopausa com idade entre 50-60 anos que foram separadas aleatoriamente em 3 grupos: (i) grupo LED, que realizou o treinamento na esteira ergométrica com fototerapia; (ii) grupo exercício, que realizou apenas o treinamento em esteira ergométrica e; (iii) grupo sedentário, que não realizou exercício físico e nem fototerapia. O treinamento foi realizado 2 vezes por semana durante 45 minutos em intensidade entre 85-90% da frequência cardíaca máxima durante 1 ano. Os parâmetros de irradiação foram 100 mW, 40 mW/cm2, tempo de tratamento de 45 minutos e 108 J/cm2 de fluência. O tratamento foi avaliado através de teste de esforço máximo em esteira ergométrica, dinamometria isocinética, antropometria, composição corporal, exames bioquímicos, qualidade de vida, densidade mineral óssea, termografia, documentação fotográfica e aspectos nutricionais. Para análise estatística foram utilizados ANOVA two-way e ANOVA one-way com ajustamentos de Bonferroni. O nível de significância foi p<0.05. Os principais resultados para o grupo LED foram: maior tolerância ao exercício máximo (&#916;Tlim=432±180seg, p=0.001 e; &#916;METs=4.2±1, p=0.01), maior potência muscular (&#916;=21±6W, p=0.04) e reduzida fadiga (&#916;=-7±4%, p=0.006). Não foram constatadas diferenças significativas na composição corporal (p&#8805;0.05), mas diferenças qualitativas na pele com redução de celulites. Houve também, a redução dos níveis de colesterol (&#916;colesterol total=- 42±23 mg/dl, p=0.0003 e &#916;LDL=-35±20 mg/dl, p=0.001), bem como, aumento da qualidade de vida (de 82±17 para 89±17, p=0.04). Não foi constatada redução significativa da massa óssea (p&#8805;0.05). Ainda, a temperatura cutânea aumentou durante o exercício com LEDs (de 33.5±0.8°C para 34.6±0.9°C, p=0.03). Os resultados mostraram que a iluminação-LED (850nm) pode potencializar o desempenho físico e os benefícios clínicos no grupo de mulheres investigado. Neste contexto, a fototerapia associada ao treinamento em esteira ergométrica pode ser potencialmente usada em protocolos de esporte, reabilitação e estética.

Made available in DSpace on 2016-06-02T19:22:50Z (GMT). No. of bitstreams: 1 2189.pdf: 840243 bytes, checksum: df5c31ed96eff502c06d8ea77cffe86d (MD5) Previous issue date: 2008-06-27 / Financiadora de Estudos e Projetos / The inability to oxidize fat is a key factor in the etiology of obesity. However, improved performance and VO2max resulting from physical training leads to increased rates of oxidation of fats. Although, there is still a lack of information about the intensity of exercise can interfere with metabolism of carbohydrates and lipids in obese women during a session of exercise and its recovery, because only in an experimental study there is a negative relationship of obesity on the reinstatement of power after a year. Therefore, this study aims to assess the behavior of the metabolism of carbohydrates and lipids in moderately obese women on a test of acute exercise effects on the intensity of ventilatory threshold and the recovery period, in the stage of pre-and post-training physical. This study had the participation of seven women slightly obese (BMI=4.03 kg/m2), with an average age of 43.0 ± 4.0 years, 163 ± 0.2±33.59 cm and previously sedentary who were submitted to the ergospirometry acute test before and after 16 weeks of training in the intensity of ventilatory threshold. During the test respiratory quotient was evaluated to determine the fats and carbohydrates oxidation during exercise and recovery period. The results found that the volunteers used predominantly the energy that comes from carbohydrates during the session of exercise (67.64% and 69.35% of the total spent provided pre-and post-training, respectively). During recovery the percentage of the fats contribution increase of (46.52% of the total oxidized) to the total energy generated, which discreetly marked with training (53.48% of the total oxidized). Based on the findings was observed that the metabolism of carbohydrates provides the muscle contraction support during the exercise in the intensity of ventilatory threshold and that the recovery period lipid metabolism is the counterpart to repay the body stores energy in obese women. / A inabilidade de oxidar gorduras é um fator chave na etiologia da obesidade. No entanto, a melhoria de performance e do VO2max advinda do treinamento físico leva a um aumento das taxas de oxidação de gorduras. Porém, ainda faltam esclarecimentos sobre como a intensidade do exercício pode interferir no metabolismo de carboidratos e de lipídeos de mulheres obesas durante uma sessão de exercício e a sua recuperação, já que apenas em estudo experimental observa-se a relação negativa da obesidade sobre a reposição da energia após um exercício. Sendo assim, o objetivo do presente estudo é de verificar o comportamento do metabolismo de carboidratos e de lipídeos de mulheres moderadamente obesas sobre efeito de um teste agudo de exercício na intensidade do limiar ventilatório e o seu período de recuperação, na condição pré e pós-treinamento físico. Para tanto, o estudo contou com a participação de sete mulheres levemente obesas (IMC=33,59 ± 4,03 Kg/m2), com média de idade de 43,0 ± 4,0 anos, 163 ± 0,2 cm e previamente sedentárias que foram submetidas ao teste agudo de ergoespirometria, no inicio e após transcorridas 16 semanas de treinamento na intensidade do limiar ventilatório. Durante o teste foi avaliado o quociente respiratório para determinação da oxidação de gorduras e de carboidratos durante o exercício e o seu período de recuperação. Com base nos resultados obtidos verificou-se que as voluntárias utilizam predominantemente a energia que advém de carboidratos durante a sessão de exercício (67,64 % e 69,35 % do total oxidado na condição pré e pós-treinamento, respectivamente). Durante a recuperação as gorduras aumentam o percentual de contribuição (46,52 % do total oxidado) para o total de energia gerada, condição discretamente acentuada com o treinamento (53,48 % do total oxidado). Com base nos achados acredita-se que o metabolismo de carboidratos oferece suporte para a contração muscular durante o exercício físico na intensidade do limiar ventilatório e que no período de recuperação o metabolismo lipídico faz a contrapartida para reposição dos estoques de energia corporal em mulheres obesas.

5 Tématem diplomové práce je fenomén lidské práce a její vztah k životnímu prost edí a p írod v rámci r stov orientovaného kapitalismu. První ást práce pomocí fenomenologické analýzy inných modalit, jak je nacházíme v díle Vita Activa Hannah Arendtové, odpovídá na otázky Co je to lidská práce? Jak se lidská práce liší od zhotovování? Jaký je vztah t chto inných modalit k p írod a životnímu prost edí? Druhá ást analýzy je zam ena na historické prom ny práce v období novov ku, jež se p ekrývá s nástupem pr myslového kapitalismu. Poslední ást pak analyzuje fenomén práce v soudobé environmentální sociologii - role práce v teorii b žícího pásu výroby (Allan Schnaiberg) a teorie akumulace kapitálu (J. B. Foster). Klí ová slova: práce, zhotovování, Hannah Arendtová, fenomenologie, kapitalismus, p íroda, b žící pás, ekonomický r st, akumulace, planetární meze, Alain Schnaiberg The aim of the thesis deals with the phenomenon of human work and its relationship to the environment and nature in the context of growth-oriented capitalism. The first part of the thesis includes phenomenological analysis of the two basic modalities: labor and work, which can be found in the Hannah Arendt's book The Human Condition. Second part of theses descirbe the crossing of those modalities during the modern times. In this part I try to...

This thesis is dealing with types of discourse of the Treadmill of prduction, that are used by Czech confederation of trade unions. In the first part of the text is the description of the theory of the Treadmill of Production and of the roles ot the three acters of the so called growth colaition, which are Labour, Capital and State. In the following part of my work I defined three types of discourse of the Treadmill of Production. The first two are dominant and I named them Competition discourse and Solidarity discourse. They both support the Treadmill of production. The third discourse uses less, it is called Revolution discouse and is used to opose the Treadmill of production. Those three types of discourse are applied in topics of teh flexibilization of work, the technological change, and the environment.

No description available.

<p> G93A SODI mice (G93A mice) are a transgenic model over-expressing a mutant human Cu/Zn-SOD gene, and are a model for amyotrophic lateral sclerosis (ALS), a predominantly motor neurodegenerative disease. Hippocampal neurogenesis in the subgranular zone (SGZ) of dentate gyms (DG) occurs throughout the life. It is regulated by many pathological and physiological processes. There is controversy with respect to the basal level of hippocampal neurogenesis and its response to exercise in neurodegenerative diseases and their mouse models. Little information regarding hippocampal neurogenesis is available in G93A mice. The present study was designed to study the impact of treadmill exercise and sex differences on hippocampal neurogenesis in this model. In addition, potential molecular mechanisms regulating hippocampal neurogenesis including growth factors (BDNF and IGFl) and oxidative stress (SOD2, catalase, 8-0Hdg, and 3-NT) were also addressed in the study. Bromodeoxyuridine (BrdU) was used to label newly generated cells. G93A and wild type (WT) mice were subjected to treadmill exercise (EX) or a sedentary (SEO) lifestyle. Immunohistochemistry was used to detect BrdU labeled newly proliferating cells, surviving cells, and their phenotype, as well as for determination of oxidative stress. BDNF and IGFl mRNA expression was assessed by in situ hybridization. Results showed that (1) G93A mice had an elevated basal level of hippocampal neurogenesis for both cell survival and neuronal differentiation, a growth factor (BDNF mRNA), and an oxidative stress marker (NT), as compared to wild type sedentary mice. (2) Treadmill running did not show any further effect on hippocampal neurogenesis, growth factors, oxidative stress, and antioxidant enzymes in G93A mice, while treadmill running promoted hippocampal neurogenes1s and expression of the growth factor (BDNF mRNA), and lowered oxidative stress (8-0Hdg) in WT mice. (3) There also were sex differences in hippocampal neurogenesis in G93A mice, whereby male G93A mice had a significant higher level of cell proliferation but a lower level of survival than female G93A mice. (4) The DG BDNF mRNA was associated with cell survival and neuronal differentiation in sedentary G93A mice, suggesting that BDNF is associated with a higher basal level of hippocampal neurogenesis in G93A mice. We conclude that G93A mice are more permissive in the context of hippocampal neurogenesis, which is associated with elevated DG BDNF mRNA expression. Running did not have impact on hippocampal neurogenesis and BDNF mRNA expression in G93A mice, probably due to a 'ceiling effect' of the already heightened basal levels of hippocampal neurogenesis and BDNF mRNA in this model. In addition, sex differences also affect hippocampal neurogenes1s, but the further study is needed to clarify the underlying molecular mechanisms. </p> / Thesis / Doctor of Philosophy (PhD)

Made available in DSpace on 2016-01-26T12:51:26Z (GMT). No. of bitstreams: 1 luisdomingosfornitano_tese.pdf: 1565670 bytes, checksum: acedd7e7a18ad6dcdbdc6b72c97ae59d (MD5) Previous issue date: 2008-09-26 / Obesity is an independent risk factor for cardiovascular disease, especially in its morbid form. Bariatric surgery is an effective therapeutic option for sustained weight loss. However, there is no consensus in these cases regarding the performance of functional tests for preoperative evaluations. Objective: The aim of the present study was to analyze clinical, electrocardiographic and hemodynamic response variables using a conventional exercise test on individuals with morbid obesity in comparison to overweight individuals. Materials and Method: Six hundred seventeen cases were included. Group I had 290 patients with morbid obesity and Group II had 327 overweight patients. All were submitted to a conventional treadmill exercise test. Classic positivity criteria were used. Results: Both groups tolerated the test well. There was no statistically significant difference in terms of positivity of the test [ST segment abnormality or angor (p=0.3863) or ST segment abnormality alone (p=0.1000)]. The significantly higher values in the obese individuals were basal heart rate (HR), basal sistolic arterial pressure (SAP), maximum SAP, basal diastolic arterial pressure (DAP), maximum DAP, chronotropic incompetence (p<0.0001) and maximum double product (p<0.0421). The significantly lower values in the obese individuals were exercise time, maximum HR and METs values (p<0.0001). Conclusions: Hemodynamic parameters were significantly different between the two groups. However, there were no differences in terms of ST segment abnormalities or effort-induced angina. The very low functional capacity and complex arrhythmia found in some obese individuals draws attention to the need for complementary investigation with the aim of diminishing the risk of postoperative heart complications. / A obesidade é fator de risco independente para doença cardiovascular, particularmente em sua forma mórbida. A cirurgia bariátrica é opção terapêutica eficaz para o emagrecimento sustentado nesses casos não havendo, entretanto, consenso sobre a realização de testes funcionais para avaliação pré-operatória. Objetivo: Analisar as respostas clínicas, eletrocardiográficas e hemodinâmicas por teste ergométrico convencional, em portadores de obesidade mórbida em comparação a indivíduos com sobrepeso. Casuística e Método: Foram incluídos 617 casos sendo o Grupo I, com 290 pacientes obesos mórbidos e o Grupo II, com 327 pacientes com sobrepeso, todos submetidos a teste ergométrico convencional em esteira. Foram utilizados os critérios clássicos de positividade. Resultados: A prova foi bem tolerada por ambos os grupos. Não houve diferença estatisticamente significante em termos de positividade do Teste (por alteração do segmento ST ou angor) [P = 0,3863] ou somente por alteração do segmento ST [P= 0,1000]. As variáveis significantemente maiores nos obesos foram: Freqüência cardíaca (FC) basal, Pressão arterial sistólica (PAS) basal; PAS máxima; Pressão arterial diastólica (PAD) basal; PAD máxima; Déficit cronotrópico (P <0,0001) e o Duplo Produto (DP) máximo (P =0,0421). Os valores significantemente menores nos obesos foram: tempo de exercício, FC máxima e valores em METS (P<0,0001). Conclusões: Os parâmetros hemodinâmicos mostraram-se significantemente diferentes entre os dois grupos não havendo, porém, diferenças em termos de anormalidades do segmento ST ou angina induzida por esforço. A capacidade funcional muito baixa e as arritmias complexas observadas em alguns dos obesos alertam para a necessidade de investigação complementar no sentido de diminuir o risco de complicações cardíacas pós-operatórias.

Consistently, reports in the literature have identified that a sedentary lifestyle contributes to the progression of a range of chronic degenerative diseases. The measurement of energy expenditure and physical activity pattern in children is a challenge for all professionals interested in paediatric health and from a broader perspective, the public health fraternity charged with considering longer term health consequences of physical inactivity. The primary objective of this thesis was to identify a suitable indirect and objective measurement technique for the assessment of energy expenditure and physical activity pattern in children. The ideal characteristics of such a technique are that it should be reproducible and have been validated against a criterion reference method. To achieve this goal, a series of methodological studies were undertaken (Chapters II and III). This work was essential to increase accuracy during the individualised laboratory calibration process and further minimise prediction errors when analysing data from 7 days of monitoring under free-living conditions in the second part of the study (Chapters IV and V). In the first study to verify the combined effect of body position, apparatus and distraction on children's resting metabolic rate (RMR), experiments were carried out on 14 children aged 8-12 (mean age = 10.1 years ± 1.4). Each participant underwent 2 test sessions, one week apart under three different situations: a) using mouthpiece and nose-clip (MN) or facemask (FM); b) sitting (SEAT) or lying (LY) and c) TV viewing (TV) or no TV viewing. In the first session, following 20 min rest and watching TV, the following protocol was used: LY: 20 min - stabilisation; 10 min using MN and 10 min using FM. Body position was then changed to seated: 20 min stabilisation; 10 min using FM; 10 min using MN. In the second session, FM and MN order was changed and participants did not watch TV. Data were analysed according to the eight combinations among the three studied parameters. Repeated measures ANOVA indicated statistically significant differences for &VO2 (p=0.01) and RMR (p=0.02), with TVMNSEAT showing higher values than TVFMLY. Bland-Altman analysis showed a bias for &VO2, &VCO2, RQ and RMR between TVFMLY and TVMNSEAT of -17.8±14.5 ml.min-1, -8.8±14.5 ml. min-1, 0.03±0.05 and -115.2±101.9 kcal.d-1, respectively. There were no differences in RMR measurements due to body position and apparatus when each variable was isolated. Analyses of distraction in three of four combinations indicated no difference between TV and no TV. In summary, different parameter combinations can result in increased bias and variability and thereby reported differences among children's RMR measurement. The second study dealt with treadmill adaptation and determination of self-selected (SS) walking speed. Assessment of individual and group differences in metabolic energy expenditure using oxygen uptake requires that individuals are comfortable with, and can accommodate to, the equipment being utilised. In this study, a detailed proposal for an adaptation protocol based on the SS was developed. Experiments were carried out on 27 children aged 8-12 (mean age = 10.3±1.2 yr). Results from three treadmill tests following the adaptation protocol showed similar results for step length with no significant differences among tests and lower and no statistically significant variability within- and between-days. Additionally, no statistically significant differences between SS determined over-ground and on a treadmill were verified. These results suggest that SS speed determined over-ground is reproducible on a treadmill and the 10 min familiarisation protocol based on this speed provided sufficient exposure to achieve accommodation to the treadmill. The purpose of the third study was to verify within- and between-day repeatability and variability in children's oxygen uptake ( &VO2), gross economy (GE) [ &VO2 divided by speed] and heart rate (HR) during treadmill walking based on SS. 14 children (mean age = 10.2±1.4 yr) undertook 3 testing sessions over 2 days in which four walking speeds, including SS, were tested. Within- and between-day repeatability was assessed using the Bland and Altman method and coefficients of variability (CV) were determined for each child across exercise bouts and averaged to obtain a mean group CV value for &VO2, GE and HR per speed. Repeated measures ANOVA showed no statistically significant differences in within- or between-day CV for &VO2, GE or HR at any speed. Repeatability within and between-day for &VO2, GE and HR for all speeds was verified. These results suggest that submaximal &V O2 during treadmill walking is stable and reproducible at a range of speeds based on children's SS. In the fourth study, the objective was to establish the effect of walking speed on substrate oxidation during a treadmill protocol based on SS. Experiments were carried out on 12 girls aged 8-12 (mean age = 9.9±1.4 yr). Each participant underwent 2 test sessions, one week apart. Workloads on the treadmill included 2 speeds slower than SS (1.6 [V1] and 0.8 km.h-1 [V2] slower than SS), SS (V3), and a speed 0.8 km.h-1 faster than SS (V4). Indirect calorimetry from respired gas measurements enabled total fat (FO) and carbohydrate (CHO) oxidation rates to be calculated according to the non-protein respiratory quotient (Peronnet and Massicote, 1991) and percentage of CHO and FO calculations using equations from McGilvery and Goldstein (1983). Repeated measures ANOVA followed by a Tukey Post Hoc test (p< 0.05) was used to verify differences in CHO and FO rates among speeds. Paired T-test was used to verify differences in CHO and FO rates between tests per velocity. The reliability between-day was assessed using intraclass correlation coefficient (ICC). Results showed significant differences for CHO among all speeds, as well as significant differences for FO between V1 and V2 against V3 and V4 in both tests. Analyses between trials per velocity showed no significant substrate use differences as well as acceptable reliability. At the self-selected speed (V3) there was an accentuation in FO reduction as well as an increase in CHO oxidation. The purpose of the fifth study was to determine whether there were differences in substrate oxidation between girls (G) and women (W) during a treadmill protocol based on SS. Experiments were carried out on 12 G aged 8-12 (mean age = 9.9±1.4 yr) and 12 W aged 25-38 (mean age = 32.3±3.8 yr). The treadmill protocol included 6 min workloads followed by 5 min rest periods. Workloads included 2 speeds slower than SS (1.6 (V1) and 0.8 km.h-1 (V2) slower than SS), SS (V3), and a speed 0.8 km.h-1 faster than SS (V4). Total fat and carbohydrate (CHO) oxidation rates were calculated from indirect calorimetry according to the non-protein respiratory quotient. Repeated measures ANOVA followed by a Tukey Post Hoc test was used to verify intra-test differences in CHO and fat oxidation rates among speeds. Intergroup differences were analysed using paired T-test. Fat utilisation in W achieved a plateau at a relative velocity 0.8 km.h-1 slower than SS, but for G, fat utilisation increased until SS, and then stabilised upon reaching the higher velocity. CHO oxidation curves rose abruptly above V2 for W, while for G the acute increase occurred after SS (V3). Collectively, these results indicate that as walking intensity increases G are able to meet the energy demands of the work by increasing fat oxidation together with the increased CHO oxidation up to SS. In contrast for W, increasing CHO oxidation is associated with an early decrease in fat utilisation at a velocity slower than the self-selected speed. The sixth study dealt with validation of indirect techniques for the measurement of energy expenditure in free-living conditions against the DLW technique. Experiments were carried out on 19 children aged 8-12 (mean age = 10.3±1.0 yr). To indirectly predict energy expenditure 12 different procedures were used. Only one procedure, combining activity and heart rate (AHbranched), was based on a group equation, the others were based on individualised regression. Three of the individually-based techniques were able to accurately predict energy expenditure in free-living conditions. These tecniques were HRPAnetRMR using HRnet [HR exercise minus sleep HR (SHR)] against PAnet (measured PA exercise minus measured RMR) and upper and lower body equations corrected by RMR; HRPAnet4act using the same procedure but corrected by the mean resting &VO2 for 4 resting activities [(4act) = supine watching TV, sitting watching TV, sitting playing computer games and standing], and HRPALBnet4act using only lower body activities and corrected by 4act. HRPAnetRMR was only slightly more accurate than HRPAnet4act and HRPALBnet4act, but this technique is only adjusted by RMR whereas the other two are heavily dependent on more complex laboratory calibration. Bland and Altman (1986) analyses showed no significant differences between AHbranched predicted and measured TEE using the DLW technique. A SEE of 79 kcal.d-1 and a mean difference of 72 kcal.d-1, with a 95% CI ranging from -238 to 93.9 kcal.d-1 was found. In addition, no significant differences between predicted HRPAnetRMR and measured TEE using DLW were found, showing an SEE of 99 kcal.d-1 and a mean difference of -67 kcal.d-1, and a 95% CI ranging from -276.6 to 141.9 kcal.d-1. AHbranched and HRPAnetRMR were both valid and similarly suitable for the prediction of energy expenditure in children under free-living conditions. Significant associations between DLWAEE and the after-school time window indicated that this time window as an important discretionary period representative of children physical activity. However, the duration of the after-school time windows should be more carefully considered. Accelerometer data showed a better association between the largest after-school time window (3.5 hr) and measured TEE. The final study, completed with 19 children aged 8-12 (10.3±1.0 yr) highlighted, under laboratory conditions across a range of walking and running speeds, the inadequacy of the use of the standard MET in children. This traditional approach overestimates energy expenditure with an increased difference linearly related to speed increments. Minute-by-minute analyses of 7 days of free-living monitoring showed an average overestimation of 64 minutes per day for moderate-to-vigorousphysical- activity (MVPA) using the standard MET compared with the individually measured MET. For all intensities, these differences were statistically significant (p< 0.001). The second part of this study showed a variability of 20% in the average time spent at MVPA when comparing HR I 140 bpm and HR > 50%P &VO2 (P &VO2 = the highest &VO2 observed during an exercise test to exhaustion). Results of the current study compared to observations in the literature showed that HR I 140 bpm consistently estimates lower MVPA time than HR > 50%P &VO2. When these two PA indices were compared with individual and standard MET measured minute-byminute, statistically significant differences were verified among all of them at MPA, but no differences were verified at VPA, except between individual and standard METs. However, whether each one of the PA indices used are under- or overestimating time at MVPA is still debatable due to the lack of a gold standard. Finally, each index used in this study classified different numbers of participants as achieving the PA target of 60 min.d-1. The wide variability between indices when attempting to classify children who are achieving the recommended target is cause for great concern because habitually these indices are utilised as screening tools in paediatric and public health settings and used to guide behavioural interventions.