Orientador: Benedito Sérgio Denadai / Banca: Mara Patrícia T. Chacon-Mikahil / Banca: Miguel de Arruda / Banca: Luiz Guilherme Antonacci Guglielmo / Banca: Emerson Franchini / Resumo: A cinética do consumo de oxigênio (V02) descreve o comportamento respiratório durante a transição repouso-exercício. Os parâmetros derivados dos ajustes (componente lento - CL e constante de tempo - t ou Tau) são utilizados para quantificar a magnitude das alterações ocorridas nesse sistema. Os objetivos deste estudo foram: 1) verificar a influência de diferentes modelos de análise [modelo matemático com três termos exponenciais (Exp3) vs. diferença do V02 entre o sexto e o terceiro minuto de exercício (AVO2 6-3 mm)] na caracterização do CL durante o exercício acima do limiar de lactato (LL) em corrida; 2) verificar os efeitos do tipo de exercício [corrida em esteira rolante (ER) vs. exercício em bicicleta ergométrica (BE)] no pico do consumo de oxigênio (VO210) e LL (expresso em ml/kg/mim e % VO2pjc) e; 3) verificar os efeitos do tipo de exercício no tVO2 e no CL da cinética do V02 durante o exercício acima do LL em meninos de 11-12 anos de idade. Participaram do estudo 20 crianças do gênero masculino aparentemente saudáveis e ativos (11,48 l 0,41 anos; 41,38 l 10,45 kg; 147,45 l 6,56 cm), nível maturacional 1 e 2 (pilosidade pubiana) que realizaram dois testes incrementais, um na ER e outro na BÊ para determinação do VO20 e do LL. Para determinação da cinética do VO2 foram realizadas duas transições de 6 minutos em cada ergômetro na intensidade de 75%A [75% A = LL + 0,75 x (VO2pico - LL)]... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The oxygen uptake kinetic (V02) explaian the respiratory behavior during restexercise transition. The parameters from the adjustment (slow component - SC and time constant - t or Tau) are usual to measure the magnitude of the alterations on this structure. The objectives of this study were: 1) to verify the influence of the two different mathematical models [three-exponential model (Exp3) and AVO2 6-3 mm] on the SC of V02 in children during running exercise, performed at above lactate threshold intensity domain (75%A); 2) to verify the effects of exercise mode (running x cycling) on the indexes related to aerobic fitness (VO2peak and blood lactate response to exercise); 3) to verify the effect of the exercise mode (running x cycling) on the tVO2 and the SC of the VO2 in children aged 11 to 12 years during above lactate threshold intensity exercise (75%). Twenty apparently healthy active boys (age = 11,48 l 0,41 years; body mass = 41,38 l 10,45 kg; hemght = 147,45 l 6,56 cm), sexual maturation levels 1 and 2 (pubic hair) took part of this study. These children performed in different days on a motorized treadmill (TM) and on a cycle ergometer (CE) the following tests: 1) an incremental test in order to determine the peak oxygen uptake (VO2peak) and the LT and; 2) a series of square-wave transitions of 6-min \- 02peak - iJ1) 111 OTT 'Lo Õe'Lerffilne Yne V02 kinetics (tVO2 and SC). The SC values determined by model Exp3 (129,69 l 75,71 mi/min and 8,4 l 2,92 %) were higher than values determined by model VO2 6-3 mm (68,69 l 102,54 mi/min and 3,6 l 7,34%)... (Complete abstract click electronic access below) / Doutor

Background: Obesity is a chronic disease characterized by a body mass index (BM1) of ≥ 30 kg/m2 which negatively impacts the musculoskeletal system and has been found to be a major contributing factor to obesity-induced biomechanical alterations during activities of daily living (ADLs). A certain level of mobility is required for all populations to maintain independence and a good quality of life becomes more difficult with excess weight. Using a reduced weight-bearing activity, such as the Alter Gravity treadmill, would be beneficial in an obese population to reduce the load on the joints and potentially decrease the risk of weight bearing injury while maintaining normal gait mechanics. The purpose of this dissertation was to determine the biomechanical effects of excess weight and weight distribution on ADLs. To address this, two different weight gain models were created to simulate central (CL) and peripheral (PL) weight gain compared to an obese group (OW), and normal weight group (UL) during different activities of daily living (ADLs). The purpose of the third study was to compare lower extremity joint kinematics and muscle activation patterns between obese and normal individuals at different levels of body support (100, 75, and 50%) while walking in the AlterG treadmill. Methods: 14 normal weight (BMI: 22.4 ± 1.8 kg/m2, age: 23.4 ± 3.6 yrs) and 17 obese (BMI: 33.2 ± 2.3 kg/m2, age: 31.6 ± 8.0 years) adults participated in different ADLs (gait and descending a set of stairs). Normal weight participants were loaded with two different external loads sufficient to increase their BMI by 5 kg/m2 (~22.6% body mass). Kinematic and kinetic data were collected with 3D motion analysis. Frontal plane hip and knee angles and moments were calculated. Results: During gait, the obese group walked at a significantly slower velocity compared to UL. Step length was 8.7% longer in UL and 7.4% longer in the CL compared to the OW. PL more closely mirrored the OW group in step length, flexion moment and extension moment and the CL more closely mirrored the obese group in sagittal plane knee and hip excursion, and peak hip flexion moment and extension moment during gait During the transition from descending stair walking to level gait, it was found that the PL, but not CL, decreased step length, increased step width, and increased proportion of the gait cycle spent in stance. During the transition from walking down the stairs to level gait it was found that CL and PL affect temporal spatial variables differently. PL also reduced peak hip adduction angle, increased peak hip flexion moment, decreased peak hip extension, decreased sagittal plane hip excursion, and decreased frontal plane hip excursion. Conversely, CL reduced peak hip flexion moment and trended to reduce peak hip extension moment. To determine the effects of reduced body mass per se on improved biomechanics, we needed a model that would prevent associated changes in segmental volume. Therefore, using an AlterG treadmill facilitated this method. At 100 % BW support, mean ST and VM EMG activity were significantly higher in the obese compared to the normal weight groups. There were also differences found at 75 % BW support in ST in the obese being greater than the normal. Conclusions: Combined, the overall results of this dissertation suggest that weight gain is able to be modeled but is variable and task specific. The CL has proven to be the weight gain model that which elicits a better biomechanical obese response when normal weight individuals are loaded. Further work is needed to understand how to truly mimic obesity with an external load.

A comparison of the effects on recovery while breathing a 97 per cent oxygen mixture and normal compressed atmospheric air after treadmill running was determined among nine male wrestlers at Utah State University. The variables examined were heart rate and percentages of oxygen and carbon dioxide in expired air. The practice of some athletic teams of administering oxygen to participants during time out periods was the motivation for this study. A great majority of the studies reviewed conclude that oxygen does not play a significant role in aiding recovery from physical activity. The experiment first consisted of eight runs on the treadmill (Quinton Model 18-49-C) to familiarize the subjects with the equipment and also to enable them to plateau in conditioning for a five minute run at 0 per cent grade at eight miles per hour. After the training period was completed, the nine subjects went through a series of six runs, each followed immediately by a five minute recovery period while breathing a 97 per cent oxygen mixture for three of the recovery periods, and a 21 per cent oxygen mixture for the other three recovery periods. Heart rate was recorded every 30 seconds during the recovery period by the use of three electrodes on the subjects. Expired air was collected with the use of the Kofrany-Michaelis Respirometer. Air samples were analyzed for percentages of oxygen and carbon dioxide by the Fry Gas Analyzer. An analysis of variance showed no significant difference in heart rate decline while breathing either gas mixture. At the end of the five minutes of recovery, the subjects expired 3 per cent of carbon dioxide regardless of which oxygen mixture was breathed. It was concluded that there were no significant differences in the effects on recovery while breathing the 97 per cent oxygen mixture or the 21 per cent oxygen mixture.

The objective of this study is to compare the caloric expenditure and oxidative sources of underwater treadmill running and land-based treadmill running at maximal and submaximal levels. Underwater running has emerged as a low load bearing form of supplementary training for cardiovascular fitness, as a way to promote recovery from strenuous exercise while maintaining aerobic fitness, and as a way to prevent injury. Prior studies have reported conflicting results as to whether underwater treadmill running elicits similar cardiorespiratory responses to land-based running. It is important to further investigate the similarities and differences between the two to determine if underwater running is as efficient as land-based running for maintenance of fitness and for rehabilitative purposes. Purpose: To compare the caloric expenditure and oxidative sources of underwater treadmill running and land treadmill running during both maximal treadmill trials to exhaustion and during 30 minute submaximal treadmill trials. Methods: 11 volunteer experienced male triathletes, ages 18-45 were recruited as participants. Each completed 6 trials total which included a maximal and submaximal oxygen consumption trial for each of three conditions: running on a water treadmill with AQx® water running shoes, running on a water treadmill without shoes, and running on a land-based treadmill. Data analysis: Data was analyzed using repeated measures ANOVAs, paired t-tests, pairwise comparisons with bonferroni adjustments, and descriptive statistics were reported. Results: For maximal oxygen consumption trials VO2, RPE, RER, and BP were not significantly different between modalities. Maximal HR was found to be significantly different between modalities, and was shown to be greater on land than in the water. For submaximal VO2, trials HR, RPE, RER, and post BP were not found to be significantly different between modalities. Average VO2, total calories expended, and pre systolic BP were found to be significantly different, and were shown to be greater on land than in water. Conclusions: While maximal exertion running on underwater treadmills seems to elicit similar cardiorespiratory responses to running on land-based treadmills, differences were seen at submaximal exertion levels. It remains unclear whether underwater treadmill running can elicit similar training stimuli as land running at submaximal levels.

Osteoarthritis (OA) is a debilitating condition affecting over 21 million persons in the United States. This number is expected to rise in the coming decades. Treatment approaches for OA focus on symptom modifying measures (i.e., pain relief) as disease modifying interventions do not currently exist. However, some of the interventions used to alleviate the symptoms of OA are also thought to have disease-modifying benefits. Two such non-surgical interventions for OA are intra-articular hyaluronan (HA) injections and physical exercise. In order to effectively study their effects in human OA, animal models that are amenable for studying intervention outcomes are needed. The research focused on developing and characterizing a progressive non-surgical model of knee OA in adult mice. This model was used to firstly, examine the capacity of intra-articular HA injections to prevent knee joint degeneration, and secondly to examine the capacity of moderate exercise to prevent onset and progression of joint degeneration. Intra-articular injections of TGF--β1 into murine knees produce synovial hyperplasia, osteophyte formation, and fibrotic changes on cartilage surfaces and joint capsules. However, additional exposure of the joints to high intensity treadmill running (biomechanical overuse) results in more widespread and focal OA-like cartilage erosions of both the tibial and femoral surfaces, similar to that described for the pathological appearance of late human knee OA. Taken together, these data support that synovitis and soft-tissue activation in early OA joints may precede and/or accelerate the process cartilage degeneration characteristic of progressive and late stage osteoarthritis. Intra-articular injections of high molecular weight HA one day following TGF--β1 injections resulted in decreased synovial hyperplasia, minimized osteophyte formation, and significantly decreased severity of cartilage lesions. A four week, alternate day, low intensity aerobic treadmill running program prior to TGF--β1 injections and overuse also resulted in decreased severity of cartilage lesions.

<p>The general aim of this work was to evaluate the outcome of specialised stroke rehabilitation and to examine the relation between both subjectively perceived and objectively assessed balance and impairments and some activity limitations. A further, integrated aim was to establish some psychometric properties and the usability of a newly developed Falls-Efficacy Scale, Swedish version (FES(S)) in stroke rehabilitation.</p><p>Seventy-three patients younger than 70 years of age with a first stroke and reduced walking ability were randomised into an intervention group (walking on a treadmill with body weight support) and a control group (walking on the ground). Time points of assessment were: on admission for rehabilitation, at discharge and 10 months after stroke. Walking training on a treadmill with body weight support and walking training on the ground were found to be equally effective in the early rehabilitation. The patients in both groups improved their walking velocity, motor function, balance, self-efficacy and ADL performance.</p><p>In a geriatric sample of 37 stroke patients examined at similar time points, significant improvements in self-efficacy, motor function, balance, ambulation and ADL occurred from admission to discharge independently of age. In comparison with observer-based balance measures, FES(S) at discharge was the most powerful predictor of ADL performance 10 months after onset of stroke.</p><p>In 30 patients with stable stroke, the overall test-retest reliability of FES(S) was found to be adequate. The internal consistency confirmed that FES(S) has an adequate homogeneity.</p><p>In a subsample of 62 patients from the original sample and in the geriatric sample, FES(S) correlated significantly with Berg’s balance scale, the Fugl-Meyer balance scale, with motor function and with gait performance. In the relatively younger group ADL (measured by the Functional Independence Measurement) correlated significantly with FES(S) on admission and at 10 months follow-up, while at discharge none of the FES(S) measures correlated significantly with ADL. In this subsample effect size statistics for detecting changes in FES(S) demonstrated very acceptable responsiveness of this scale during the early treatment period and during the total observation period</p><p>In the light of these findings assessment and treatment of self-efficacy seems relevant in stroke rehabilitation. </p>

Exercise training has consistently been shown to increase fat utilization during exercise, while conflicting results have been reported on the effects of sex and age on fuel metabolism during exercise. PURPOSE: The primary objective of this investigation was to compare fat and carbohydrate utilization during exercise among males and females varying in age and training status. METHODS: 8 groups of 10 subjects each were formed based upon trained (T)/untrained (U), male (M)/female (F), and young (Y)/older (O): TYM, TYF, UYM, UYF, TOM, TOF, UOM, UOF. All female subjects were experiencing regular menstrual cycles, not using oral contraceptives, and were tested in the mid-follicular phase of their menstrual cycle. The young subjects averaged 21.3 ��1.7 yr and older subjects 40.1 ��1.9 yr. All subjects exercised for 35 minutes on a treadmill at an intensity just below their ventilatory threshold. Substrate utilization was indicated by the respiratory exchange ratio (RER), and a 2x2x2 factorial ANOVA was used to determine whether age, sex, and training status have independent or interacting effects on substrate-utilization variables, and t-tests were used for post-hoc comparisons. RESULTS: The average RER during exercise was lower in trained subjects (0.841��.023) compared to untrained subjects (0.884��.021) (P < .05). There was no difference in the average RER during exercise between the young (0.860��.026) and older (0.865��.034) groups of subjects. The average RER during exercise was lower for untrained females (0.860��.027) than untrained males (0.870��.032) (P < .05), but there was no difference in fat and carbohydrate utilization between trained males (0.843��.023) and trained females (0.838��.022). CONCLUSION: The major finding of this study was that untrained females utilized proportionately more fat during exercise compared to untrained males, but there was no difference in fat and carbohydrate utilization between trained females and trained males. Another finding was that a 20-year difference in age was not sufficient for an age effect to be evident in fat utilization during moderate exercise. / Graduation date: 2013

The general aim of this work was to evaluate the outcome of specialised stroke rehabilitation and to examine the relation between both subjectively perceived and objectively assessed balance and impairments and some activity limitations. A further, integrated aim was to establish some psychometric properties and the usability of a newly developed Falls-Efficacy Scale, Swedish version (FES(S)) in stroke rehabilitation. Seventy-three patients younger than 70 years of age with a first stroke and reduced walking ability were randomised into an intervention group (walking on a treadmill with body weight support) and a control group (walking on the ground). Time points of assessment were: on admission for rehabilitation, at discharge and 10 months after stroke. Walking training on a treadmill with body weight support and walking training on the ground were found to be equally effective in the early rehabilitation. The patients in both groups improved their walking velocity, motor function, balance, self-efficacy and ADL performance. In a geriatric sample of 37 stroke patients examined at similar time points, significant improvements in self-efficacy, motor function, balance, ambulation and ADL occurred from admission to discharge independently of age. In comparison with observer-based balance measures, FES(S) at discharge was the most powerful predictor of ADL performance 10 months after onset of stroke. In 30 patients with stable stroke, the overall test-retest reliability of FES(S) was found to be adequate. The internal consistency confirmed that FES(S) has an adequate homogeneity. In a subsample of 62 patients from the original sample and in the geriatric sample, FES(S) correlated significantly with Berg’s balance scale, the Fugl-Meyer balance scale, with motor function and with gait performance. In the relatively younger group ADL (measured by the Functional Independence Measurement) correlated significantly with FES(S) on admission and at 10 months follow-up, while at discharge none of the FES(S) measures correlated significantly with ADL. In this subsample effect size statistics for detecting changes in FES(S) demonstrated very acceptable responsiveness of this scale during the early treatment period and during the total observation period In the light of these findings assessment and treatment of self-efficacy seems relevant in stroke rehabilitation.

No description available.

The purpose of this investigation was to determine the effects of caffeine supplementation on caffeine tolerant and caffeine naïve individual’s lymphocyte counts, apoptosis and migration levels. In addition, effects of exercise on post-caffeine ingestion lymphocyte counts, apoptosis and migration levels were determined. It was hypothesized that caffeine would alter the immune system cell counts, but that exercise would be able to restore the immune system to homeostasis. Seventeen Western Kentucky University students were tested (males n=7, females n=10; n=7: caffeine tolerant= 200mg or more per day group, n=9: caffeine naïve= 50mg or less per day group). In this double-blind investigation, all participants completed two exercise bouts: 30 min of treadmill running at 60-80% HRR once with a placebo drink before exercise and once with 6 mg/kg body weight of caffeine drink completed in a counterbalanced manner. Blood was taken at rest, 30 min after drink ingestion, immediately post exercise, and 60 min post exercise. Blood was stained with antibody markers (Annexin V to determine apoptotic cell counts, CX3CR1 to determine cell migration, CD4=helper T cells, CD8=cytotoxic T cells, CD19=B cells). Blood was analyzed using flow cytometry. We found that cytotoxic T cells showed significant increases following the caffeinated run in both groups combined (tolerant and naïve, p=0.001) and specifically in the naïve group on the caffeine run (p=.004). We did not see any significant changes in CD4, or CD19 cell counts. There were no significant changes in CD4, CD8 or CD19 cell migration or apoptosis. Our results showed that caffeine supplementation causes an increased effect on cytotoxic T cells counts when combined with exercise, and this effect was greater for the caffeine naïve group. The combined effects of caffeine and exercise may have elevated the plasma catecholamine and cortisol levels which are associated with immune cell function and movement. CD8 cells have a greater density of β-receptors, which are influenced by catecholamine, and may explain the increase in their cell counts compared to CD4 and CD19.