Ao longo dos últimos anos observou-se um aumento no número de idosos no mundo, com isso faz-se necessário buscar terapias que amenizem os danos relacionados e também elucidar os mecanismos envolvidos neste processo. O exercício físico tem sido sugerido como uma ferramenta importante, não farmacológica, para atenuar os déficits relacionados à idade. Ainda, estudos recentes sugerem uma relação entre o processo de envelhecimento cerebral e o desequilíbrio de mecanismos epigenéticos, contudo, estes dados ainda não são conclusivos. Sabe-se que o grau de neuroplasticidade varia com a idade e que as estruturas encefálicas podem responder diferentemente à exposição ao exercício. Estudos demonstram que o córtex pré-frontal está envolvido em funções de alta ordem como atenção, tomada de decisão e memória de trabalho. Portanto, o objetivo deste trabalho foi avaliar os efeitos de diferentes protocolos de exercício físico (sessão única e exercício diário moderado) sobre a modulação de marcadores epigenéticos em córtex pré-frontal de ratos Wistar de 3 e 21 meses de idade. Os animais foram submetidos ao protocolo de sessão única (20 minutos) ou o exercício diário moderado (20 minutos durante 14 dias), 1 hora após a última sessão foram eutanasiados. O córtex pré-frontal foi dissecado e a acetilação da H4, o conteúdo da DNA metiltransferase (DNMT1 e DNMT3b), assim como a atividade da histona metiltransferase H3K27 foram analisadas. Os resultados serão apresentados na versão completa desta dissertação. / Over the past few years the number of elderly people has increased in the world, therefore it is necessary to search therapies that ameliorate age-related deficits as well as elucidate the mechanisms involved in this process. Physical exercise has been suggested as an important non-pharmacological approach to alleviate the age-related decline. Furthermore, recent studies have suggested a relationship between the process of brain aging and imbalance of epigenetic mechanisms, however, these data are not conclusive. It is well described that prefrontal cortex is involved in higher functions like attention, decision making and working memory. Then, the aim of this study was to investigate the effects of two exercise protocols (single session and daily moderate exercise) on the modulation of epigenetic markers in the prefrontal cortex from Wistar rats of 3- and 21- months-old. Animals were submitted to single session protocol (20 minutes) or the daily moderate exercise (20 minutes for 14 days), and 1hour after the last exercise session animals were euthanized. Prefrontal cortex was dissected out and acetylation of H4, the content of DNA methyl transferase (DNMT1 and DNMT3B), as well as histone methyltransferase H3K27 activity were analyzed. Results will be presented in the full version.

abstract: The benefits of exercise have been recommended in typical and other special populations. However, the evidence for persons with Down syndrome (DS) is still limited. This study was aimed at investigating the impact of an acute bout of aerobic exercise intervention on motor performance, executive function and intrinsic motivation in adolescents and young adults with DS. Ten participants with DS were assigned to an exercise group, who walked on a incremental treadmill protocol for 20 minutes. The exercise intensity was achieved at 66% of their predicted maximum heart rate. Another ten participants with DS were assigned to an attentional control group, who watched a video for 20 minutes. Measures of fine manual dexterity (e.g., Purdue Pegboard test), manual force production (e.g., grip strength test), processing speed (e.g., visual choice reaction time test), verbal processing (e.g., verbal fluency test), attention shifting ability (e.g., The Dimensional Card sorting test), and inhibitory control (e.g., Knock and Tap test) were tested pre and post intervention. An intrinsic motivation scale (e.g., enjoyment and effort) was conducted after the intervention. First, results showed participants significantly improved their performance in manual force production and Knock and Tap Test after the exercise intervention. While it has been proposed that exercise increases arousal status, neurotransmitters, or cerebral vasculature, the exact mechanisms in persons with DS are still unknown. However, our results showed that after treadmill walking, motor and cognitive improvements can be found in individuals with DS, even in a single exercise session. In addition, participants reported higher scores in enjoyment after video viewing than exercise, which may a result from musical effect or too much emphasis on external rewards in their early participation in exercise. These may imply that participants had low intrinsic motivation to an active lifestyle. Further, scores in effort were significantly higher after exercise than video viewing, which indicated their capabilities to perceive their physical exertion. However, other motivational regulations (e.g., introjected and identified regulations) have shown the relationship with exercise behavior in this population. Thus, further study should consider divergent motivational factors in order to implement an effective exercise program. / Dissertation/Thesis / Ph.D. Kinesiology 2013

Previously, Whipp et. al. (J. Appl. Physiol.: Respirat. Environ. Exerc. Physiol. 50(1):217-221, 1981) demonstrated the feasibility of determining four parameters of aerobic function, identified as maximum oxygen uptake (μVO_2), VO_2 at anaerobic threshold (θan), the time constant for oxygen uptake kinetics (rVO_2) and work efficiency (η), using a short duration ramped bicycle ergometer exercise test. Because of the importance of being able to measure these parameters on a variety of measurement instruments a short duration ramping treadmill protocol has been developed. The ability of this protocol to determine the four aerobic parameters has been validated against conventional methods. The results of this investigation indicate that μVO_2, θan, rVO_2 and, η may be obtained from a single, short-duration ramping treadmill test.

Maximal oxygen uptake (VO2max) is the internationally recognized measure of a person's cardiorespiratory fitness. Currently the most accurate way of assessing one's true VO2max involves the use of maximal exercise tests, which require the use of specialized equipment, and are time consuming and costly. The purpose of this study was to determine the validity of the submaximal Siconolfi step test to estimate VO2max. A second purpose was to determine if body fat percentage improved the validity. Thirty-six individuals underwent a maximal treadmill test, in which VO2max was directly measured, and the step test. Results indicate that, although VO2max estimates generated by the Siconolfi step test are highly correlated to true VO2max (r =.887; p<.01), the values consistently underestimated a person's aerobic fitness. It was also determined that body fat percentage did not contribute to the prediction of VO2max.

Gait, pain, and self-efficacy alterations in osteoarthritis (OA) patients may be precursors for pathological alterations and are important variables to examine in an aquatic therapy study aimed at improving mobility. A greater understanding of these alterations will be useful for the treatment of OA and the prevention of OA progression. The purpose of this thesis was twofold: to review the effects of certain land and aquatic therapies on gait kinematics and mobility of people with osteoarthritis, and to examine the effects of short-term aquatic treadmill exercise on gait kinematics, perception of pain, and mobility in OA patients. A direct comparison of water versus land treadmill exercise was used to determine the acute effectiveness of aquatic therapy on gait kinematics, pain, and self-efficacy. Fourteen participants diagnosed with osteoarthritis of the knee performed three consecutive exercise sessions for each mode of exercise. Gait kinematics, pain, and self-efficacy were measured before and after each intervention. Angular velocity gain score during stance for left knee extension was significantly higher for aquatic treadmill exercise compared to land treadmill exercise by 38.1% (p = 0.004). Similarly, during swing, the gain scores for angular velocity were also greater for left knee internal rotation and extension by 65% and 20%, respectively (p = 0.004, p = 0.008). During stance, the joint angle gain score for left hip flexion was greater for land exercise by 7.23% (p = 0.007). Similarly, during swing, the angular velocity gain score for right hip extension was significantly greater for aquatic exercise by 28% (p = 0.01). Only the joint angle gain score for left ankle abduction during stance was significantly higher for land exercise by 4.72% (p = 0.003). No other joint angle gain scores for either stance or swing were significantly different for either aquatic or land treadmill exercise (p = 0.06-0.96). Perceived pain was 100% greater for land than aquatic treadmill exercise (p = 0.02) and self-efficacy gain scores were not different between conditions (p = 0.37). The present study demonstrated that an acute training period on an aquatic treadmill did influence joint angular velocity and arthritis-related joint pain. Although acute effects of training (i.e., pain, angular velocity) improve after aquatic rather than land training, it is unclear whether or not aquatic exercise is a better long-term alternative to land exercise, and further longitudinal research is needed to examine gait kinematic changes after an increased training period of aquatic exercise.

No description available.

Populations that utilize deep water running (DWR) are described in Chapter I. A review of the literature concerning maximal and submaximal responses during DWR, shallow water running and swimming is presented in Chapter II. The protocols to elicit maximal responses during DWR and treadmill running (TMR), subject characteristics, and statistical methods employed are described in Chapter III. The results, presented in Chapter IV, indicate that the DWR protocol is a reliable test for eliciting peak oxygen consumption and heart rate. Furthermore, the metabolic responses during DWR are lower than TMR. Chapter V discusses factors which might limit maximal responses during DWR. Chapter VI contains suggestions for further research. Raw data are presented in Appendix A.

A common measurement of body temperature during exercise in a hot, humid environment is mean skin temperature collected from 3-12 sites on the body. However, such an approach fails to demonstrate localized differences in skin temperature that are likely to exist as a function of gender. The purpose of this study was to examine potential differences in skin temperature between men and women at 17 different locations on the body. Young women (21 ± 1 y; n = 11) and men (23 ± 3; n = 10) were recruited to complete a 60-min walk/jog interval protocol in a hot (34 ± 1 °C), humid (64 ± 8%) environment while skin temperature was measured. Data was analyzed using a repeated-measures ANOVA (p < 0.05) and location of interaction effects determined using a Fisher’s least squares difference test. We observed a higher change (p < 0.05) from baseline skin temperatures (ΔTsk) for women in three locations: left upper back (women: avg. ΔTsk = 4.12 ± 0.20 °C; men: avg. ΔTsk = 2.70 ± 0.10 °C), right upper back (women: avg. ΔTsk = 4.19 ± 0.07 °C; men: avg. ΔTsk = 2.92 ± 0.05 °C), and right mid-back (women: avg. ΔTsk = 4.62 ± 0.14 °C; men: avg. ΔTsk =3.55 ± 0.09 °C). Individual time differences between genders occurred after 7- (left upper back) and 15-min (right upper back, right mid-back) of exercise and were maintained until the end of exercise. Women have a greater increase in skin temperature at three locations on the back following the onset of exercise in a hot, humid environment. This report provides important information regarding the implications of women exercising in a hot, humid environment.

Eight sedentary elderly subjects (X̅ age = 83.4yr), including two males and six females, were evaluated to determine the effects of a low intensity, chair-based exercise program on selected physiological parameters. Exercise sessions were held 3 alternate days per week, 45 minutes per session, for 8 weeks. Subjects were exercise tested before and after training using a modification of the Smith and Gilligan chair step test; this is a multi-level graded exercise test suitable for very old subjects with aerobic exercise capacities of approximately 2-4 METs. Upon completion of training, group data analyses showed no significant adaptations in resting heart rate or blood pressure, exercise heart rate or blood pressure, peak exercise performance, nor for subject rating of perceived exertion at a fixed exercise intensity. A significant increase (p < 0.05) was observed post-training in the immediate post-exercise blood lactic acid response. Separating subjects (n=4) into high (91% attendance) and moderate (49% attendance) compliers, statistically significant differences were found for training related changes in several physiological parameters. Between-group analysis also showed significant changes (p < 0.05) in the chair exercise performance time. Post-training, the high compliers improved their total exercise tolerance (time) by 33%, whereas the moderate compliers exercise time was 22% less as compared to pre-training. A significant difference (p < 0.05) was also observed between groups in their perception of effort at a fixed-load in the exercise test. After training, the high compliers judged their effort to be 12% less at a fixed load in the chair exercise test, while the moderate compliers showed no significant changes (p < 0.05). Blood lactic acid responses were significantly higher (p < 0.05) after training for the high compliance group but no such change was found in the HLa response of the moderate compliers. There were no significant changes in resting or exercise heart rate and blood pressure responses in either the high or moderate compliance groups. The results of this study suggest that physiological adaptations do not occur in old individuals in response to a low intensity exercise program. Given these preliminary findings, further investigations are indicated to determine the effects of increased frequency and duration of physical activity programs on additional physiological parameters. / Master of Science

The direct effect of spouse presence during graded exercise testing on anxiety and performance has not been previously delineated. Therefore, the purposes of this study were to (a) ascertain if spouse presence during graded exercise testing affects state anxiety or physiological performance variables, and (b) determine differences in psychological status between cardiac patients and healthy adults.