Modelos bioenergéticos de dois, três e quatro parâmetros podem ser usados para prescrever a velocidade crítica (VC) sendo que o último modelo melhor descreve a relação entre velocidade (v) e tempo de exaustão (tlim) em nadadores. O objetivo do presente estudo foi verificar as respostas metabólicas ao se nadar em intensidade equivalente à VC4par até exaustão e verificar a validade de predizê-la somente por meio de um teste de 400 m em nado crawl (T400). Para tal, esta pesquisa foi desenvolvida em duas etapas: na primeira, oito nadadores e quatro nadadoras classificados entre os oito melhores em suas provas no último Campeonato Brasileiro Juvenil de Natação (15,6 ± 0,9 anos, 63,0 ± 7,2 kg, 174,9 ± 8,3 cm de estatura, 180,7 ± 10,4 cm de envergadura, 280,2 ± 17,6 s nos 400 m nado crawl = 78,7 ± 3,3 % do recorde mundial para a prova em piscina de 25 m) realizaram testes máximos de 50, 100, 200, 400, 800 e 1500 m em ordem randomizada e com 24 h de intervalo para calcular a VC4par. Na segunda etapa, consumo de oxigênio (VO2), concentração de lactato sanguíneo ([La]), frequência cardíaca (FC) e esforço percebido (EP, escala de Borg de 6-15) foram mensurados no repouso, após o aquecimento, à cada 10 min e na exaustão em um teste retangular com velocidade controlada com duração máxima de 60 min correspondente à VC4par. Resultados: os nadadores suportaram nadar à 100% da VC4par entre 13 e 62 min. O VO2 se estabiliza a partir de, aproximadamente 10 min de teste, não atingindo seu valor máximo antes da exaustão (63,2 ± 10,5% do VO2max). [La] comportase entre uma faixa de estabilização a aumentos sem estabilização (7,2 ± 1,8 mmol·l-1 na exaustão). FC no momento exaustão situou-se em 93,0 ± 4,9da FCmax. EP aumenta sem estabilizar-se (18,3 ± 1,7 na exaustão). A relação entre a VC4par e a VN do T400 (V400) em nadadores de nível nacional é obtida pela equação VC4par = (0,9252 * V400) – 0,01. Conclusão: A VC4par situa-se no domínio de intensidade muito pesado, próxima ao limite inferior do mesmo e pode ser prescrita pelo T400. / Two, three and four bioenergetic parameter models can be used to prescribe the critical velocity (VC). The four-parameter model best describes the relationship between velocity (v) and time to exhaustion (tlim) in swimmers. The aim of this study was to determine the metabolic responses when swimming in intensity equivalent to VC4par until exhaustion and verify the validity of predicting it only through a test on 400 m front crawl (T400). To this end, this research was conducted in two stages: stage one, eight male swimmers and four female swimmers ranked among the top eight in their events at the last Brazilian Youth Swimming Championship (15.6 ± 0.9 years, 63.0 ± 7,2 kg, 174.9 ± 8.3 cm in height, 180.7 ± 10.4 cm of arm span, 280.2 ± 17.6 s in the 400 m freestyle = 78.7 ± 3.3% of world record short course) conducted maximum efforts of 50, 100, 200, 400, 800 and 1500 m in randomized order and with 24 hours of interval for calculating the VC4par. In the second stage, oxygen consumption (VO2), blood lactate concentration ([La]), heart rate (FC) and perceived exertion (EP, Borg scale 6-15) were measured at rest, after warm up, every 10 min and at exhaustion during a rectangular test with controlled speed, with a maximum duration of 60 min at 100%VC4par. Results: swimmers supported between 13 and 62 min at 100%VC4par. At this intensity VO2 stabilizes from approximately 10 minutes of testing, not reaching its maximum value before the exhaustion (10.5 ± 63.2 %VO2max). [La] behaves within the range of stabilization increases without stabilization (7.2 ± 1.8 mmol · l-1 in the exhaustion). FC at exhaustion stood at 93.0 ± 4.9% FCmax. EP increases without stabilizing (18.3 ± 1.7 in the exhaustion). The relationship between VC4par and the swimming velocity of the T400 (V400) in swimmers of national level can be obtained by equation VC4par = (0.9252 * V400) - 0.01. Conclusion: VC4par lies to the very heavy intensity domain, near the lower limit, and can be prescribed by the T400.

Diversos aspectos metabólicos e comportamentais possuem uma estreita relação com as condições do ambiente, havendo um compromisso entre as condições naturais e a dinâmica de modificações sobre os organismos. Devido ao grande índice de degradação ambiental proveniente da atividade humana nos últimos tempos, populações de anfíbios têm sido particularmente mais afetadas devido a sua alta sensibilidade a alterações ambientais. Em uma paisagem fragmentada, a manutenção de metapopulações viáveis é um importante fator a persistência das populações. Dentro deste contexto, este estudo propõe investigar as relações entre a fragmentação florestal e habilidade das algumas espécies de anuros para se deslocar entre os fragmentos, ou entre estes e corpos d\'água. Assim, realizamos comparações, fisiológicas e comportamentais intra e interespecífica de espécies de anuros residentes em paisagens contínuas e fragmentadas em duas localidades da Floresta Atlântica, com base em suas características morfológicas. De acordo com nossos resultados, as diferenças ambientais entre as paisagens estão relacionadas com as diferenças morfofisiológicas entre as espécies. / In the last few decades, human activity has changed environmental condition, resulting in amphibian populations decline all around the world. In this study we analyze the relationships between forest fragmentation and the ability of some frog species to move between forest fragments or between fragments and breeding sites. Our study focus relies on anuran locomotor performance and supporting physiology, and the relationship between these traits and resistance to forest fragmentation. We compare morphological, physiological and behavioral traits between populations of anurans species living in different landscapes (continuous or fragmented) of two sites in the Atlantic Forest. According to our data, differences in environmental conditions of landscape are related to morpho-physiological traits. This relationship, however, depends on the site of the Atlantic Forest and also varies between species.

A infusão aguda de insulina promove aumento da atividade nervosa simpática e do fluxo sangüíneo muscular, sendo esses efeitos influenciados pela sensibilidade do organismo à ação da insulina no metabolismo de carboidratos. Por outro lado, a execução de uma única sessão de exercício aeróbio diminui a atividade nervosa simpática, aumenta o fluxo sanguíneo muscular e pode modificar a sensibilidade à insulina pós-exercício. Dessa forma, a execução prévia de uma única sessão de exercício físico pode modificar as respostas fisiológicas à infusão aguda de insulina, essa influência pode ser diferente em indivíduos sensíveis e resistentes à ação desse hormônio. Para investigar essa problemática, 18 homens saudáveis foram submetidos a dois clampeamentos euglicêmicos/hiperinsulinêmicos realizados, em ordem aleatória, 90 minutos após 45 minutos de: a) exercício no cicloergômetro em 50% do VO2pico (Exercício) ou b) repouso sentado (Controle). Posteriormente, os indivíduos foram divididos em dois grupos: sensíveis (n=8) e resistentes (n=10) à insulina, com base no índice de sensibilidade à insulina da amostra total. Antes e durante os clampeamentos, a glicemia, a insulina plasmática, a pressão arterial (oscilométrico), a freqüência cardíaca (EGC), a atividade nervosa simpática muscular (microneurografia) e o fluxo sanguíneo do antebraço (pletismografia) foram medidos. O exercício físico: a) reduziu a glicemia nos dois grupos, b) diminuiu a insulina plasmática durante os clampeamentos nos indivíduos resistentes e a aumentou nos sensíveis, c) não modificou a sensibilidade à insulina nos resistentes e a reduziu nos sensíveis, d) não modificou o aumento da pressão arterial sistólica promovido pela infusão de insulina, que era maior nos sensíveis, e) aumentou a elevação pressão arterial média em resposta à infusão de insulina nos indivíduos sensíveis, f) no grupo sensível, diminuiu a pressão arterial diastólica basal e aumentou essa pressão durante a infusão de insulina, g) aumentou a freqüência cardíaca, sem modificar sua resposta à infusão de insulina, h) reduziu a atividade nervosa simpática basal, sem modificar a resposta de aumento dessa atividade durante a hiperinsulinemia, I) aumentou o fluxo sanguíneo muscular basal, sem modificar a resposta desse fluxo à infusão de insulina, que aumentava apenas nos indivíduos sensíveis, j) reduziu a resistência vascular do antebraço basal, impedindo a diminuição dessa resistência com a infusão de insulina. Em conclusão: a execução prévia de uma sessão de exercício aeróbio modifica a resposta à hiperinsulinemia aguda de forma diferente em indivíduos sensíveis e resistentes à ação desse hormônio / Acute insulin infusion increases sympathetic nervous activity, and muscle blood flow. Moreover, these effects are influenced by insulin sensitivity on carbohidrate metabolism. On the other hand, a single bout of aerobic exercise decreases sympathetic activity, increases muscle blood flow, and can increase insulin sensitivity during the post-exercise period. Thus, it is possible that previous exercise can change physiological responses to acute hyperinsulinemia, and this influence might be different in insulin-resistant and sensible subjects. To test this hypotesis, eighteen healthy males underwent two euglycemic/hyperinsulinemic clamps performed, in a random order, 90 minutes after 45 minutes of: a) cycle ergometer exercise at 50% of VO2peak (Exercise), or b) sitting rest (Control). After the experiments, subjects were divided in two groups: sensibles (n=8), and resistants (n=10) to insulin action, based on insulin sensitivity index of the total sample. Before and during the clamps, glycemia, plasma insulin, blood pressure (oscilometric), heart rate (EGC), sympathetic nervous activity (microneurography), and blood flow (plethismography) were measured. Aerobic exercise: a) reduced glycemia in both groups, b) decreased plasma insulin during the clamps in the resistant group, and increased it in the sensible one, c) did not change insulin sensitivity in the resistant subjects, but decreased it in the sensible ones, d) did not change systolic blood pressure increase promoted by insulin infusion, which was greater in the sensible group, e) enhanced mean blood pressure increase to insulin infusion in sensible subjects, f) in the sensible group, reduced baseline diastolic blood pressure, and increased it during hyperinsulinemia, g) increased heart rate, without changing its increase during insulin infusion, h) decreased baseline sympathetic nervous activity, and did not change its increase during hyperinsulinemia, i) increased baseline forearm blood flow, without changing blood flow response to insulin infusion, which was characterized by an increase only in the sensible subjects, j) reduced baseline forearm vascular resistance, abolishing the reduction observed during insulin infusion. In conclusion: previous aerobic exercise modifies physiological responses to acute hyperinsulinemia in different ways in insulin-sensible and resistant subjects

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / People living at high altitudes present compensatory adjustments to the hypoxic stimulation, such as physiological, morphological and functional adaptations. Humans have been submitted to intermittent hypoxic training (IHT) to achieve better athletic performance and to treat chronic diseases. The benefits related to IHT have been attributed to hematological, muscular, mitochondrial and plasmatic changes. An experimental model of altitude simulation was used on horses to assess the response of clinical, hematological and blood gas parameters to intermittent hypoxia. Seven horses were submitted to 30 one hour long hypoxia treatment sessions during 16 days (D1-D16). Heart (HR) and respiratory (RR) rates were measured on all sessions at time T0 (normoxia) and after 15, 30, 45 and 60 minutes of hypoxia. Blood samples for hematological evaluation were obtained on D0 (normoxia), D8 (O2 12%), D16 (O2 12%), while animals were in normoxia. Arterial blood gases were measured at T0 and after 30 and 60 minutes of hypoxia on D1 (O2 17%), D6 (O2 13%), D11 (O2 12%) and D16 (O2 12%). Bone marrow aspiration was performed to evaluate erythropoiesis on D0, D8, D16, D23 (post-trial normoxia) and D30 (post-trial normoxia). Untrained horses tolerated hypoxia at 17% O2. HR was lower at 14% O2 compared to 17% O2 (0, 15, 45 and 60 minutes) (p<0.001). PaO2 and SaO2 at 30 (P<0.05 and P<0.01) and 60 minutes (P<0.01 and P<0.001) decreased between 17% and 12% O2. PaCO2 increased at T0 (p<0.05) between 17% and 13% O2 and 17% and 12% O2. Myeloid:erythroid ratio decreased between D1 and D23, and RR and hematology values did not change during or along sessions. This experimental model successfully promoted cardio-circulatory adaptation in horses to hypoxia. / Habitantes de regiões com altitude elevada apresentam adaptações fisiológicas, morfológicas e funcionais altamente compensatórias em resposta ao estímulo criado pela hipóxia. Seres humanos vêm sendo submetidos a tratamentos de hipóxia intermitente (IHT) na busca por melhor desempenho esportivo e como tratamento de doenças crônicas. Os benefícios do IHT têm sido atribuídos a alterações hematológicas, musculares, mitocondriais e no volume plasmático. Um modelo experimental de simulação de altitude foi usado em cavalos para avaliar as alterações de parâmetros clínicos, hematológicos e gasométricos frente à hipóxia intermitente. Sete animais foram submetidos a 30 sessões de uma hora de hipóxia durante 16 dias (D1-D16). A freqüência cardíaca (FC) e respiratória (FR) foi aferida em todas as sessões, nos tempos T0 (normóxia) e após 15, 30, 45 e 60 minutos de hipóxia. Amostras de sangue para hemograma foram obtidas no D0 (normóxia), D8 (12% de O2) e D16 (12% de O2). Os gases sanguíneos foram avaliados em T0 e aos 30 e 60 minutos de hipóxia no D1 (17% de O2), D6 (13% de O2), D11 (12% de O2) e D16 (12% de O2). Punções da medula óssea foram realizadas para avaliação da eritropoiese no D0, D8, D16, D23 e D30 (normóxia pós-experimento). Os cavalos não treinados toleraram bem a hipóxia a 17% de O2. A FC foi menor aos 14% de O2 que aos 17% de O2 (0, 15, 45 e 60 minutos de hipóxia) (p<0,001). A PaO2 e a SaO2 aos 30 (P<0,05 e P<0,01) e 60 minutos (P<0,01 e P<0,001) diminuiu entre 17% e 12% de O2. A PaCO2 aumentou em T0 (p<0,05) entre 17% e 13% de O2 e entre 17% e 12% de O2. A relação de células mielóides:eritróides diminuiu entre o D1 e o D23, e a FR e parâmetros hematológicos não variaram durante ou entre as sessões. Este modelo experimental de hipóxia intermitente pode ser utilizado e promove adaptações cárdiocirculatórias em cavalos.

The purpose of this thesis was to extend our understanding of the assessment and interpretation of aerobic exercise function of paediatric patients with cystic fibrosis (CF). The first investigation sought to establish (1) the validity of traditional criteria to verify maximal oxygen (V ̇O2max) during a maximal cardiopulmonary exercise test (CPET); and (2) the utility of supramaximal verification (Smax) to confirm V ̇O2max. Traditional criteria significantly underreported V ̇O2max, whilst Smax was shown to provide a valid measurement in this patient group. The reproducibility of this CPET protocol, over the short- (48 h) and medium- (4-6 weeks) term, was then established in study two. V ̇O2max was repeatedly determined with no learning effect over 48 h (typical error (TE): ∆150 mL; ∆9.3%) and 4-6 weeks (TE: ∆160 mL; ∆13.3%). Supplementary maximal and submaximal CPET parameters should be incorporated for a comprehensive evaluation of a patient, however they are characterised by greater variability over time. The influence of mild-to-moderate CF on aerobic exercise function and the matching of muscle O2 delivery-to-O2 utilisation during ramp incremental exercise to exhaustion were then examined in study three. Aerobic function was impaired in CF, indicated by very likely reduced fat-free mass normalised V ̇O2max (mean difference, ±90% CI: -7.9 mL∙kg-1∙min-1, ±6.1), very likely lower V ̇O2 gain (-1.44 mL∙min-1∙W-1, ±1.12) and a likely slower V ̇O2 mean response time (MRT) (11 s, ±13). Arterial oxygen saturation was lower in CF, supporting the notion that centrally mediated O2 delivery may be impaired during ramp incremental exercise. Although a faster rate of fractional O2 extraction would be expected in the face of reduced O2 delivery, this was not observed, suggesting additional impairment in O2 extraction and utilisation at the periphery in CF. The fourth study then demonstrated the clinical utility of CPET to assess the response to 12 weeks treatment with Ivacaftor, using a case-based design. Whilst one patient with relatively mild disease demonstrated no meaningful change in V ̇O2max, the second demonstrated a 30% improvement in V ̇O2max, due to increased O2 delivery and extraction. Furthermore, changes in aerobic function were detected earlier than spirometric indices of pulmonary function. This study demonstrated that CPET represents an important and comprehensive clinical assessment tool and its use as an outcome measure in the functional assessment of patients is encouraged. Study five investigated the V ̇O2 kinetics in this patient group. During moderate intensity cycling, the phase II V ̇O2 time constant (τ) (p = 0.84, effect size (ES) = 0.11) and overall MRT (p = 0.52, ES=0.33) were not slower in CF. However, both were slowed during very heavy intensity cycling (p = 0.02, ES = 1.28 and p = 0.01, ES = 1.40, respectively) in CF. Cardiac output and muscle deoxygenation dynamics were unaltered in CF, however, the arterial-venous O2 content difference (C(a-v ̅)O2) was reduced (p=0.03) during VH and ∆C(a-v ̅)O2 correlated with the phase II τ (r= -0.85; p=0.02) and MRT (r = -0.79; p=0.03) in CF. This study showed that impaired oxidative muscle metabolism in this group is exercise intensity-dependent and mechanistically linked to an intrinsic intramuscular impairment, which limits O2 extraction and utilisation. In conclusion, this thesis has provided guidelines for a valid and reproducible CPET protocol for children and adolescents with mild-to-moderate CF, demonstrated the utility of CPET as clinical outcome measure and furthered our understanding of the factors responsible for impaired aerobic exercise function in this patient group.

Hyperkalemic periodic paralysis is characterized by myotonic discharges followed by paralysis. Caused by a mutation in the gene encoding for NaV1.4 channel, patients do not experience symptoms during infancy, but the onset starts between 1-10 years of age. The symptoms severity then increases with age until adolescence. A large increase in gene expression marked by an increase in oxidative capacity of muscles has also been reported in HyperKPP. It is possible that the onset of symptoms is related solely to NaV1.4 channel content/activity reaching a critical level. It is also possible that the onset of some symptoms are due to defective NaV1.4, while other symptoms and the increase in severity with age are related to changes in membrane components as a result of changes in gene expression. To test these possibilities, the progression of paralysis and changes in fiber types were followed with age in HyperKPP mice in relation to changes in NaV1.4 content and activity. Changes in fiber types (index of changes in gene expression), started after the onset of paralysis was observed, which coincided with NaV1.4 channels reaching maximum expression. Therefore, the onset of symptoms was related to defective NaV1.4 channels.

The purpose of this study is to explore the cultural meanings of Asian/American and Asian female skaters through an examination of the US media narratives of them from a period beginning in the early 1980s and ending in the late 2000s. Main subjects are Tiffany Chin (Taiwanese American), Kristi Yamaguchi (Japanese American), Michele Kwan (Chinese American), and a group of Asians such as Japanese skaters (Midori Ito, Yuka Sato, Shizuka Arakawa and Asada Mao), Chinese skaters (Chen Lu), and Korean skater (Yu-Na Kim). Drawing on Reading Sport Project as a methodological tool and the Sporting Black Atlantic as a theoretical tool, I deploy what I call the Sporting Yellow Pacific as a theoretical reading frame for this project. It refers to a genealogical space that is geographically transnational and historically neo colonial, in which the difference of Asian females is epistemologically subjected as ‘Other’ in the ontological space of American white national imagination. With this frame, I attempt to conceptualize the skaters as what I call the yellow female skater, a racialized and gendered sporting icon, which signifies a number of sets of complex and sometimes ambivalent images: nationally American but racially Asian; culturally favored as a model minority but also perilous and foreign as yellow peril; naturally primitive and/or childish but also hyper-sexual and exotic; and, biologically talented or superior but aesthetically underdeveloped. Through an analysis of these images in relation to representation, discourse, and power, I eventually write this dissertation as a genealogy that traces a historical trajectory of the yellow female skater.

Since the 1970s, millions of Americans have raised billions of dollars for nonprofit organizations through philanthropic fitness events. In 2013, 27 of the 30 largest charity events netted nearly $1.7 billion for health-related nonprofits. Two central questions guide this work: How do those who run marathons and raise funds for breast cancer make sense of their participation?; and To what extent do the notions of a moral citizen and philanthropy shape the meanings that they make of philanthropic fitness events? This work utilizes a year of interviews with nine women who ran the 26.2 with Donna: The National Marathon to Finish Breast Cancer in Jacksonville, Florida, in 2012 and/or 2013. I also conducted participant observation, running the marathon in 2013, and nonparticipant observation from the sidelines in 2012. My project examines the changing cultural context of the marathon and the meanings of consumerism, fitness, giving, morality, and breast cancer as a source of social connection. It also examines participants' skepticism toward both health-related nonprofit organizations and their financial status. The result is a more nuanced explanation regarding individuals' choices to participate in endurance-length philanthropic fitness events. The marathon is important to these runners' relationships with breast cancer-breast cancer the disease, breast cancer the concept, breast cancer the identity. This project finds that besides simply finding a community of like-minded individuals at a race, the healing element of the 26.2 with Donna is key to the formation of personal connections to the race that create long-term marathoner-fundraisers. The runners experience the 26.2 with Donna inside a perfect "pink bubble" of women's culture that surrounds the race and co-opts its participants. That space is overlain with notions of an imagined sisterhood based on individual and communal improvement through the consumption of pink-ribboned products.

Two thousand and twelve marked the fortieth anniversary of Title IX and the first Summer Olympic Games in which all attending nations sent female competitors. Too often, scholars of sport history conservatively frame the experiences of girls and women within a narrative of progress. College women's sport participation in particular is framed as a linear narrative beginning with the "new woman's" foray in college physical training, the non-competitive interwar coed, and the post Title IX female athlete. It is within this narrative that the college play day, a sport practice emerging in California and Washington in 1926 began to gain momentum as an additional form of extramural competition for college women. In this dissertation I interrogate which historical and societal forces contributed to the invention, diffusion, and evolution of the college play day. Though the play day is briefly included in descriptive narratives about women's physical activity and sport during the interwar era, deeper explorations are absent. This study aims to further elucidate the extent and variety of forms that the play day took. I aim to explore its general value within the college setting and its reception among women physical educators, colleagues, and play day participants. An additional research question I pose is what are the roles and contributions of certain individuals, alliances, and organizations involved in the invention, adoption, and evolutions of the college play day? Last, I question whether or not the play day is a site in which gender relations or other intersecting relations of power were reproduced, constructed, or transformed?

This study investigated physiological and performance changes of a national-level 69 kg female weightlifter after 3 competition phases over a 28-week training period. The athlete first trained for a regional championship (weeks 1–12), followed by a local competition (weeks 13–23) and the national championship (weeks 24–28). Body mass, vastus lateralis cross-sectional area (CSA), and unloaded and loaded squat jump performance were assessed weekly during each 4-week competition phase. Serum biomarkers and dynamic midthigh pulls were assessed before and after each competition phase. Weightlifting performance goals were met for the regional championship (total = 200 kg) and the local competition (total = 193 kg), but not the national championship (total = 196 kg). She lost more body mass in preparation for Nationals (−6.0 kg) compared with regionals (−2.5 kg) and the local competition (+2.2 kg). Vastus lateralis CSA very likely decreased after Nationals (precision = 99%, effect size = 2.08). Her testosterone:cortisol ratio likely increased (88%, 2.64), whereas interleukin-6 (79%, 2.47) and tumor necrosis factor–alpha (81%, 3.59) likely decreased after Nationals. Serum myostatin (99%, 1.95) and decorin (99%, 1.96) very likely decreased after the local competition. Unloaded squat jump height likely increased the week of regionals (89%, 0.95) and the local competition (99%, 1.83), whereas unloaded and loaded squat jump height possibly (69%, 0.99) and likely (82%, 1.52) decreased the week of Nationals. Dynamic midthigh pull vertical displacement likely increased after regionals (93%, 0.84) and likely decreased after Nationals (94%, 0.87). These findings indicate that biomarkers of stress, inflammation, and hypertrophy are related to changes in training volume-load; however, performance measures are needed to assess competition preparedness. Considering the reductions in muscle CSA corresponding with the large reductions in body mass and underperformance at the national championship, sport scientists, and coaches should instruct weightlifters to not attempt large losses in body mass (e.g., >3 kg) close to competition (e.g., <1week).