Orientador: Antonio Carlos de Moraes / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Educação Fisica / Made available in DSpace on 2018-08-11T02:55:02Z (GMT). No. of bitstreams: 1 Okano_AlexandreHideki_D.pdf: 920056 bytes, checksum: e16cc719a684f3e7e9a4132585472631 (MD5) Previous issue date: 2008 / Resumo: O propósito do presente estudo foi verificar o efeito de diferentes tempos de esforço:pausa (E:P) no exercício intermitente de alta intensidade sobre as respostas neuromusculares, o lactato sangüíneo (LACS) e a percepção subjetiva de esforço (PSE). Doze ciclistas, do sexo masculino, foram submetidos a três protocolos de esforços intermitentes de alta intensidade. Os protocolos de exercício intermitente longo (EIL = 4 x 30 s, com intervalo de dois minutos entre cada teste), exercício intermitente médio (EIM = 8 x 15 s, com um minuto de intervalo) e exercício intermitente curto (EIC = 16 x 7,5 s, com intervalo de 30 s entre os testes) foram realizados aleatoriamente, com intervalo de 48 horas entre cada protocolo. Os índices de decréscimo da potência de pico e do trabalho foram mais elevados (P<0,05) nos protocolos de EIL (12 e 15%) e EIM (11 e 13%) quando comparado ao EIC (4 e 7%), respectivamente. O trabalho total realizado nos protocolos EIM (70143 J) e EIC (67071) foram superiores (P<0,05) em relação ao EIL (62011). Houve redução (P<0,05) da amplitude dos sinais eletromiográficos (EMG-RMS) com o decorrer dos esforços nos protocolos de EIL e EIM, porém, sem alterações no EIC. Com relação à freqüência mediana, houve redução somente no protocolo de EIL. O LACS e a PSE foram superiores nos EIL e EIM quando comparados ao protocolo de EIC. De acordo com os resultados podemos concluir que os protocolos EIL e EIM acarretam em maiores níveis de fadiga neuromuscular, LACS e PSE / Abstract:The purpose of this study was to evaluate the effects of different work: rest time relation during high-intensity intermittent exercise on the neuromuscular responses, blood lactate levels (LAC) and rate of perceived exertion (RPE). Twelve male cyclists performed three protocols of high intensity intermittent exercise. The protocols of long intermittent exercise tests (IEL = 4 x 30 s, with two minutes rest between each test), medium intermittent exercise (IEM = 8 x 15 s, with one minute rest between the tests) and short intermittent exercise (IES = 16 x 7,5 s, with 30 s rest between tests) were conducted randomly, separated by 48 hours. The rates of decline in peak power and total work were higher (P<0,05) on the protocols IEL (12 and 15%) and IEM (11 and 13%) when compare to IES (4 and 7%), respectively. The total work done during protocols IEM (70143 J) and IES (67071 J) were higher (P<0,05) when compare to IEL (62011J). There was a reduction (P<0,05) in electromyography activity (root-mean-square RMS) during the protocols of IEL and IEM, however, no significant changes in IES were found. Considering the median frequency from the electromyography signals, there was only significant reduction in IEL. The LAC and RPE were higher in IEL and IEM when compared to IES. According to the results is possible to conclude that the IEL and IEM protocols cause higher neuromuscular fatigue, LAC and RPE / Doutorado / Ciencia do Desporto / Doutor em Educação Física

It has been established that Wingate-based high-intensity training (HIT) consisting of 4 to 6 x 30-s all-out sprints interspersed with 4-min recovery is an effective training paradigm. Despite the increased utilisation of Wingate-based HIT to bring about training adaptations, the majority of previous studies have been conducted over a relatively short timeframe (2 to 6 weeks). However, activity during recovery period, intervention duration or sprint length have been overlooked. In study 1, the dose response of recovery intensity on performance during typical Wingate-based HIT (4 x 30-s cycle all-out sprints separated by 4-min recovery) was examined and active recovery (cycling at 20 to 40% of V̇O2peak) has been shown to improve sprint performance with successive sprints by 6 to 12% compared to passive recovery (remained still), while increasing aerobic contribution to sprint performance by ~15%. In the following study, 5 to 7% greater endurance performance adaptations were achieved with active recovery (40%V̇O2peak) following 2 weeks of Wingate-based HIT. In the final study, shorter sprint protocol (4 to 6 x 15-s sprints interspersed with 2 min of recovery) has been shown to be as effective as typical 30-s Wingate-based HIT in improving cardiorespiratory function and endurance performance over 9 weeks with the improvements in V̇O2peak being completed within 3 weeks, whereas exercise capacity (time to exhaustion) being increased throughout 9 weeks. In conclusion, the studies demonstrate that active recovery at 40% V̇O2peak significantly enhances endurance adaptations to HIT. Further, the duration of the sprint does not seem to be a driving factor in the magnitude of change with 15 sec sprints providing similar adaptations to 30 sec sprints. Taken together, this suggests that the arrangement of recovery mode should be considered to ensure maximal adaptation to HIT, and the practicality of the training would be enhanced via the reduction in sprint duration without diminishing overall training adaptations.

Orientador: Daniele Cristina Cataneo / Resumo: Introdução: Há evidências que o exercício físico é benéfico em pacientes com câncer pois fornece independência funcional ao indivíduo. Entretanto pouco se sabe sobre os efeitos do treinamento intervalado de alta intensidade (HIIT) nesses indivíduos, fazendo-se necessário uma revisão sistemática para reunir estudos que utilizaram esta modalidade de exercício, possibilitando o conhecimento de seus reais efeitos no paciente com câncer. Objetivos: Avaliar a efetividade, viabilidade e segurança do treinamento intervalado de alta intensidade nos pacientes com câncer. Método: Foi conduzida uma revisão sistemática (RS) de ensaios clínicos randomizados (ECR), quase randomizados ou controlados que avaliaram o HIIT em pacientes com câncer. Foram avaliados os desfechos: Efetividade (condicionamento físico e qualidade de vida), Viabilidade (fadiga, composição corporal e aderência ao tratamento) e Segurança (efeitos adversos e sobrevida). Todas as buscas foram conduzidas sem restrição de idiomas ou datas nas seguintes bases de dados: Lilacs, Pubmed, Cochrane, Web of Science, Embase e Scopus. Resultados: A pesquisa identificou 333 estudos, dos quais 20 artigos foram incluídos. A duração média da intervenção foi de 9,5 ± 4,7 semanas, com 2,9 ± 0,2 sessões por semana. A meta- análise do consumo de oxigênio (VO2) para o condicionamento físico mostrou superioridade do HIIT em comparação aos Cuidados Usuais (UC) (MD 3,29, IC95% 1,94, 4,64; p<0,00001), mas não quando comparado ao exercício modera... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Introduction: There is evidence that physical exercise is beneficial in cancer patients as it provides functional independence to the individual. However, little is known about the effects of high-intensity interval training (HIIT) on these individuals, making a systematic review necessary to gather studies that used this exercise modality, enabling the knowledge of its real effects on cancer patients. Objectives: To evaluate the effectiveness, feasibility and safety of high-intensity interval training in cancer patients. Method: A systematic review of randomized, quasi-randomized or controlled clinical trials that evaluated HIIT in cancer patients was conducted. The outcomes evaluated were: Effectiveness (physical conditioning and quality of life), Viability (fatigue, body composition and adherence to treatment) and Safety (adverse effects and survival). All searches were conducted without restriction of languages or dates in the following databases: Lilacs, Pubmed, Cochrane, Web of Science, Embase and Scopus. Results: The research identified 333 studies, of which 20 articles were included. The average duration of the intervention was 9.5 ± 4.7 weeks, with 2.9 ± 0.2 sessions per week. The meta-analysis of oxygen consumption (VO2) for physical conditioning determined superiority of HIIT compared to Usual Care (UC) (MD 3.29, 95% CI 1.94, 4.64; p <0.00001), but not when compared to moderate continuous intensity exercise (MIC) (MD 1.83, 95% CI -0.40, 4.06; p = 0.11). Likewise, d... (Complete abstract click electronic access below) / Mestre

This study investigated the effects of ungraded running and graded walking as modalities of HIIT on enjoyment, perceived exertion, and affect. 29 healthy males and females (aged 23.3 ± 5.1) volunteered to participate in the study. Participants completed six visits to the laboratory: the first was a medical screening to ensure safety of the participants. For the second and third visits, participants completed two maximal treadmill exercise tests, one running and one walking. On the fourth visit, the speed needed for the run HIIT (running speed: 6.9 ± 1.2mph) and the grade needed for the walk HIIT (walking speed: 3.3 ± 0.3mph, walking grade: 17.2 ± 3.1%) experimental trials were confirmed. During the last two visits, participants completed both of the two (run HIIT and walk HIIT) randomized and counterbalanced experimental trials. Affective valence was measured at baseline and post-exercise. The single-item Feeling Scale (FS) and the Borg 6-20 RPE scale (both overall exertion and legs-only exertion) were used to measure in-task ratings of affect and exertion. The Physical Activity Enjoyment Scale (PACES) and FS were used to measure post-exercise ratings of enjoyment and affect. Results revealed a main effect for condition for post-exercise enjoyment (p < 0.001), with the run HIIT being more enjoyable. A main effect was also found for time for both overall exertion and legs-only exertion (p < 0.001 for both interactions), with the walk HIIT producing higher exertion ratings. There was a main effect for condition of legs-only exertion (p = 0.004), again walk HIIT produced higher exertion ratings. Lastly, there was a main effect when comparing 20% and 100% of total time in the run HIIT and the walk HIIT conditions, for both overall exertion and legs-only exertion (p < 0.001 for all interactions). This shows that exertion increased over time for both conditions. Exertion ratings, both overall and legs-only tended to be highest during the run HIIT condition when compared to the walk HIIT. The opposite was true for affective valence, the ratings were higher in the run HIIT condition than the walk HIIT. In conclusion, the perceptual responses in this study, which represent enjoyment, exertion and affective valence, were generally more favorable during the run HIIT condition. These results support previous findings to suggest that doing a running protocol is a well-tolerated and favorable modality for HIIT exercise.

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The purpose of this study was to investigate the role exercise intensity plays in reducing body weight and percent body fat in overweight women. Subjects were randomized to either a high intensity interval training group (IT) or a lower intensity steady state training group (ST). Each group exercised 3 times per week for 8 weeks and expended 300 kcal per exercise session. VO2max, body composition, and resting metabolic rate (RMR) were measured pre and post training. RMR was measured after exercise at week 2 to see if intensity levels affected RMR. VO2max and body composition improved in IT but not in ST. Neither group showed a change in RMR from pretest to posttest; however, IT had an increase in RMR 24 hours post-exercise whereas ST did not. These findings show that high intensity interval exercise produces improvements in body composition, fitness, and acute RMR compared to low intensity steady state training.

This thesis sought to advance our understanding of the physiological and health-related adaptations to low-volume interval training. Three separate studies were conducted in previously sedentary adults who trained three times per week. High-intensity interval training (HIIT) involved ten, 60-second cycling efforts at an intensity that elicited ~90% of maximal heart rate, interspersed with 60 seconds of recovery, whereas sprint interval training (SIT) involved three, 20-second ‘all-out’ cycling efforts interspersed with 2 minutes of recovery. Both protocols involved a brief warm-up and cool-down, resulting in 25- and 10-minute sessions for HIIT and SIT, respectively. Peak oxygen uptake (VO2peak), skeletal muscle mitochondrial content as reflected by the maximal activity and protein content of mitochondrial enzymes, and glycemic control based on oral glucose tolerance tests (OGTTs), intravenous glucose tolerance tests (IVGTTs) or continuous glucose monitoring (CGM), were determined before and after training. Study 1 found that 6 weeks of HIIT in the fed or fasted state increased VO2peak and mitochondrial content in women, but insulin sensitivity based on OGTTs was unchanged. Study 2 showed that 6 weeks of SIT increased VO2peak and mitochondrial content in men and women, whereas mean 24-hour glucose based on CGM was reduced in men only. Study 3 directly compared 12 weeks of SIT to traditional moderate-intensity continuous training (MICT) in men. The two protocols elicited similar improvements in VO2peak, mitochondrial content and insulin sensitivity based on IVGTTs, despite SIT involving a five-fold lower exercise volume and time commitment. This work advances our understanding of the potency of brief, intense exercise training to induce physiological remodeling and improve cardiometabolic health. It also highlights potential sex-specific adaptations to interval training that warrant clarification. Further investigation into the mechanisms of physiological remodeling to HIIT and SIT is needed, as are large-scale randomized clinical trials that compare these protocols to MICT. / Thesis / Doctor of Philosophy (PhD) / This thesis examined physiological and health-related adaptations to interval training, which involves brief bouts of intense exercise interspersed with recovery periods. One protocol involved alternating 60-second hard and easy cycling efforts for 20 minutes; the other involved three, 20-second ‘all-out’ sprints interspersed with 2 minutes of recovery. Both protocols improved indices of cardiometabolic health in previously inactive adults who trained three times per week for 6 weeks, even though the amount of exercise performed was lower than typically recommended in public health guidelines. When the latter protocol was directly compared against traditional endurance training, the improvement in cardiometabolic health after 12 weeks was the same, despite a five-fold difference in the total amount of exercise performed. Our findings highlight the effectiveness of short bursts of high-intensity exercise for improving health. These results may appeal to individuals who cite “lack of time” as a barrier to exercise.

No description available.

<p>This thesis investigated the acute and chronic responses of human skeletal muscle to high-intensity exercise, with a particular focus on markers of mitochondrial content, and the potential for nutrition to manipulate the adaptive response in recreationally active individuals. The acute response was primarily assessed via measurement of signalling proteins and mRNA species linked to exercise-induced mitochondrial biogenesis. The chronic response was determined via changes in the protein content or maximal activities of mitochondrial enzymes after training. Study 1 examined whether the manner in which a given amount of high-intensity cycling work was performed (i.e., in an intermittent or continuous fashion) altered the acute metabolic response to exercise, and whether the acute response was indicative of longer-term adaptations. Despite the similar acute activation of signalling proteins after the intermittent and continuous matched-work exercise protocols, 6 wk of training with the continuous protocol did not increase mitochondrial content, contrary to what we have previously shown after 6 wk training with the intermittent protocol. This suggests that the intermittent application of a low-volume, high-intensity stimulus is important to elicit training-induced increases in mitochondrial content. Furthermore, Study 1 showed that acute changes in specific signalling proteins did not necessarily predict chronic adaptations. Studies 2 and 3 examined whether specific nutritional interventions, previously shown to modulate acute exercise capacity or metabolic response, altered the mitochondrial adaptive response to several weeks of HIT. Neither manipulating carbohydrate availability between twice daily training sessions, or chronic ingestion of β-alanine, augmented skeletal muscle adaptations in response to 2-6 wk of HIT. It is possible that small influences of nutrition were overwhelmed by the potency of HIT, which stimulated marked increases in mitochondrial content in this population. Overall this thesis advances our basic understanding of the skeletal muscle adaptive response to HIT and the influence of nutrition.</p> / Doctor of Philosophy (PhD)

<p>This thesis examined the effect of high-intensity "sprint" interval training (SIT) on aerobic-based exercise performance and metabolic adaptations in human skeletal muscle. It has long been recognized that several weeks of interval-based training increased skeletal muscle oxidative capacity; however, little was known regarding the minimum "dose" of SIT necessary to elicit this adaptive response or the time-course and magnitude of adaptation in other markers of skeletal muscle metabolic control. Our general hypothesis was that low-volume SIT would induce rapid improvements in a wide array of metabolic variables that were comparable to traditional high-volume endurance training (ET). Healthy young men and women were recruited to perform four to six 30- second "all out" Wingate Tests, three times per week with one to two days of recovery, for up to six weeks. The weekly dose of SIT corresponded to ~10 minutes of maximal cycling exercise (-225-300 kJ) over a total training time commitment of 60-90 minutes, including recovery. The SIT response was compared against control subjects who performed no training or an ET group who performed up to one hour per day of moderate-intensity cycling exercise, five days per week for six weeks (-2250 kJ per week). Our major findings were that one to two weeks of SIT increased performance during aerobic-based exercise (time-to-fatigue tests and time-trials of varying duration) and the maximal activity or total protein content of mitochondrial enzymes and transport proteins associated with carbohydrate metabolism (e.g., citrate synthase, cytochrome oxidase, glucose transporter 4). Six weeks of SIT or ET induced similar increases in markers of skeletal muscle carbohydrate (pyruvate dehydrogenase E1a protein content) and lipid oxidation (3-hydroxyacyl CoA dehydrogenase maximal activity) and peroxisome-proliferator-activated receptorgamma coactivator-1a protein content, and similar reductions in phosphocreatine and glycogen utilization during matched-work exercise. These data suggest that SIT is a time-efficient strategy to increase skeletal muscle oxidative capacity and to induce specific metabolic adaptations during exercise that are comparable to ET.</p> / Doctor of Philosophy (PhD)