O dano muscular induzido pelo exercício (DMIE) é um fenômeno que ocorre ao realizarmos um exercício com o qual não estamos habituados, seja pela modalidade, volume ou intensidade. Além disso, esta condição está fortemente relacionada com contrações excêntricas ou gestos que predominantemente envolvam este tipo de contração, causando prejuízos funcionais importantes e diminuindo o desempenho. Diante disto, estratégias para acelerar o processo de recuperação muscular vem sendo investigadas. Dentre elas, a recuperação ativa, técnica muito utilizada no meio prático e que consiste na execução de exercícios com intensidade baixa ou moderada buscando melhorar a recuperação após uma sessão de treino mais intensa. No entanto, nenhum estudo comparou duas formas de recuperação ativa com exercícios aeróbios até o momento, além dos estudos experimentais da área apresentarem qualidade metodológica frágil. Com isso, o objetivo desta dissertação é comparar o efeito da recuperação ativa em esteira e em cicloergômetro sobre marcadores de dano muscular. Para isso, trinta voluntários do sexo masculino foram alocados de forma randomizada em três grupos: grupo esteira (GE, n = 10), grupo cicloergômetro (GCI, n = 10) e grupo controle (GC, n = 10). Avaliações da contração isométrica voluntária máxima (CIVM), dor, concentração plasmática de creatina kinase (CK) e lactato desidrogenase (LDH) e espessura e ecogenicidade dos músculos reto femoral (RF) e vasto lateral (VL) foram realizadas pré, 24h, 48h e 72h após um protocolo indutor de dano muscular, constituído por cinco séries de 10 contrações excêntricas máximas em dinamômetro isocinético. Após o protocolo indutor de dano muscular, os sujeitos realizaram a intervenção de acordo com o grupo em que foram alocados, com duração de 30 minutos e intensidade de 60% do VO2máx, independente da modalidade. Não foram observadas diferenças significativas entre os grupos nos parâmetros de caracterização da amostra. Não houve diferença significativa entre os grupos em todas as variáveis analisadas. Houve redução significativa no torque nos períodos imediatamente após (IP), 24h, 48h e 72h comparado ao período Pré em todos os grupos. Houve aumento significativo da dor nos períodos 24h, 48h e 72h comparado ao período Pré em todos os grupos. Houve aumento significativo na espessura do músculo RF 24h após o protocolo de dano muscular. A ecogenicidade foi maior tanto no RF quanto no VL nos períodos de 48h e 72h quando comparada ao período Pré. Não houve diferença significativa nas concentrações plasmáticas de CK e LDH entre os períodos de avaliação. Os resultados do presente estudo permitem concluir que a execução de recuperação ativa nos parâmetros adotados, seja em cicloergômetro ou esteira, não modifica o processo de recuperação após dano muscular. / The exercise-induced muscle damage (EIMD) is a phenomenon that occurs when we execute an unusual exercise, either by type, volume or intensity. Furthermore, this condition is strongly associated with eccentric contractions or gestures which predominantly involve this type of contraction, causing significant loss of function and decreasing performance. In view of this, the search for strategies to accelerate muscle recovery process has been investigated. Among them, active recovery, technique widely used in practical means and which consists in carrying out exercises with low or moderate intensity seeking to improve recovery after a more intense training session. However, no studies have compared two types of active recovery yet, besides the experimental studies presented fragile methodological quality. Thus, the aim of this study is to compare the effect of active recovery on a treadmill and cycle ergometer on muscle damage markers. For this, thirty male volunteers were randomly divided into three groups: treadmill group (EG, n = 10), cycle ergometer group (GCI, n = 10) and control group (CG, n = 10). Evaluations of maximal voluntary isometric contraction (MVIC), pain, plasma concentration of creatine kinase (CK) and lactate dehydrogenase (LDH) and muscle thickness and echo intensity of the rectus femoris (RF) and vastus lateralis (VL) were performed before, 24h, 48h and 72h after the muscle damage protocol, comprising five sets of 10 maximum eccentric contractions using an isokinetic dynamometer. After muscle damage protocol, the subjects performed the intervention according to the group they were allocated, lasting 30 minutes with an intensity of 60% VO2max, regardless of the type. Significant differences between the groups in the sample characterization parameters were observed. There was no significant difference between groups in all variables. There was a significant reduction in torque in the periods immediately after (IP), 24h, 48h and 72h compared to the Pre period in all groups. There was a significant increase in pain at times 24h, 48h and 72h compared to the Pre period in all groups. A significant increase in muscle thickness of RF was observed in 24h period. The echo intensity was higher in both RF and VL in periods of 48h and 72h compared to the Pre period. There was no significant difference in plasma concentrations of CK and LDH between the evaluation periods. Our results illustrate that the performance of active recovery, in the adopted parameters, either in cycle ergometer or treadmill, does not change the process of recovery after muscle damage.

O treinamento aeróbio moderado tem sido reconhecido como um importante estimulador do sistema imune, no entanto o efeito deste na infecção bacteriana não tem sido extensivamente estudado. Nosso objetivo foi avaliar se o exercício aeróbio moderado prévio à infecção por S. pneumoniae influencia a resposta inflamatória pulmonar. Camundongos BALB/C foram divididos em 4 grupos: Controle (animais sedentários; não infectados); S. pneumoniae (animais sedentários e posteriormente infectados); Exercício (animais treinados; não infectados); Exercício + S. pneumoniae (animais treinados e posteriormente infectados). Os animais foram submetidos a um programa de treinamento físico aeróbio durante 4 semanas, e 72 horas após a última sessão de exercício, os animais receberam instilação nasal de S. pneumoniae (linhagem M10) e foram avaliados 12 horas (fase aguda) ou 10 dias (fase tardia) após a instilação. Na fase aguda, o grupo S. pneumoniae apresentou um aumento de: resistência e elastância do sistema respiratório, número total de células, neutrófilos, linfócitos e macrófagos no lavado broncoalveolar (BAL), células polimorfonucleares no parênquima pulmonar e TNF-alfa e IL-1beta no homogenato pulmonar. O exercício físico atenuou significantemente esses parâmentros. Além disso, o exercício físico resultou em aumento da expressão de enzimas antioxidantes no pulmão (CuZnSOD and MnSOD). Na fase tardia, o grupo Exercício + S. pneumoniae apresentou redução no número total de células e macrófagos no BAL, células polimorfonucleares no parênquima pulmonar e IL-6 no homogenato pulmonar comparado ao grupo S. pneumoniae. Nossos resultados sugerem um efeito protetor do exercício aeróbio moderado contra a infecção bacteriana pulmonar. Esse efeito é provavelmente secundário ao efeito do exercício no balanço oxidante-antioxidante / Moderate aerobic exercise training has been recognized as an important stimulator of the immune system, but its effect on bacterial infection has not been extensively studied. Our aim was to determine whether moderate aerobic exercise training prior to S. pneumoniae infection influences pulmonary inflammatory responses. BALB/c mice were divided into 4 groups: Control (sedentary without infection); S. pneumoniae (sedentary with infection); Exercise (aerobic training without infection); Exercise + S. pneumoniae (aerobic training with infection). Animals underwent aerobic exercise training for 4 weeks. 72 h after last exercise training, animals received a challenge with S. pneumoniae (strain M10) and were evaluated either 12 h (acute phase) or 10 days (late phase) after instillation. In acute phase, S. pneumoniae group had an increase in respiratory system resistance and elastance; number of total cells, neutrophils, lymphocytes and macrophages in bronchoalveolar lavage fluid (BAL); polymorphonuclear cells in lung parenchyma; and levels of TNF-alfa and IL-1beta in lung homogenates. Exercise training significantly attenuated the increase in all of these parameters. In addition, exercise induced an increase in expression of antioxidant enzymes (CuZnSOD and MnSOD) in lungs. In late phase, Exercise + S. pneumoniae group exhibited a reduction in number of total cells and macrophages in BAL, in polymorphonuclear cells in lung parenchyma and in levels of IL-6 in lung homogenates compared to S. pneumoniae group. Our results suggest a protective effect of moderate exercise training against respiratory infection with S. pneumoniae. This effect is most likely secondary to an effect of exercise on oxidant-antioxidant balance

Introdução: A prática regular de exercício tem sido grandemente associada a efeitos benéficos em doenças pulmonares crônicas como asma e doença pulmonar obstrutiva crônica. Poucos estudos têm avaliado os benefícios do exercício aeróbico na lesão pulmonar aguda (LPA). Objetivo: Neste estudo nós investigamos os mecanismos envolvidos no papel do exercício físico em diminuir os danos pulmonares causados pela LPA induzida por lipopolissacarídeo (LPS). Métodos: Camundongos Balb/c foram divididos em quatro grupos: Controle (CTR), Exercício (Exe), LPS e Exercício+LPS (Exe+LPS). Os animais dos grupos Exe e Exe+LPS foram treinados em baixa intensidade por 60 minutos/dia, 3x/semana, durante 5 semanas. A instilação intratraqueal de LPS (200 /animal) foi realizada 48 horas após o último teste físico nos grupos LPS e Exe+LPS. Vinte e quatro horas após a instilação de LPS nós analisamos os níveis de óxido nítrico exalado (NO), a mecânica respiratória e a densidade de neutrófilos no tecido pulmonar. Nós analisamos também os níveis de extravasamento de proteína, contagem de células totais e diferenciais e os níveis de IL-1, IL-6, KC, IL-10 and TNF- no lavado bronco-alveolar (LBA). Os níveis de IL-6 e IL-10 também foram avaliados no plasma e tecido pulmonar. A expressão de receptores de glicocorticóide (Gre) e da enzima superóxido dismutase (SOD) foi analisada no tecido pulmonar. As atividades enzimáticas de glutationa peroxidade (GPX), catalase (CAT), glutationa redutase (GR), e SOD foram determinadas no homogenato de pulmão por espectrofotometria. O nível de malonaldeído (MDA) foi quantificado no homogenato de pulmão. Resultados: A instilação de LPS resultou em aumento nos níveis de NO exalado (p<0,01), aumento do número de células e neutrófilos no LBA (p<0,001), aumento do número de neutrófilos no parênquima pulmonar (p<0,001), aumento dos valores de resistência e elastância pulmonar (p=0,01), aumento dos níveis de extravasamento de proteína (p0,02), aumento dos níveis de IL-6 e IL-10 no plasma (p<0,02) e aumento dos níveis de IL-1, IL-6 e KC no LBA (p0,005), comparado ao grupo CTR. O exercício aeróbico (grupo Exe+LPS) diminuiu significativamente os níveis de NO exalado (p=0,006), a densidade de neutrófilos no parênquima pulmonar (p=0,004), os valores de resistência e elastância pulmonar (p = 0,003), aumentou a expressão de IL-6, IL-10 e Gre no tecido pulmonar (p0,04) e aumentou o nível de IL- 1 no LBA (p=0,04) comparado ao grupo LPS. Conclusão: Nossos resultados mostram que o exercício desenvolve um importante papel em proteger o pulmão dos efeitos inflamatórios da LPA induzida por LPS. Os efeitos do exercício são principalmente mediados pelo aumento da expressão de citocinas antiinflamatórias, sugerindo que o exercício aeróbico pode modular o balanço inflamatório, antiinflamatório na fase inicial na SARA. / Background: The regular practice of exercise has been increasingly associated to benefic effects on chronic pulmonary conditions such as asthma and chronic obstructive pulmonary disease. Few studies have also reported the effects of aerobic exercise on acute lung injury (ALI). Objective: In this study we investigated the mechanisms involved in the role of exercise in attenuating the pulmonary changes in a model of lipopolysaccharide (LPS)-induced ALI. Methods: BALB/c mice were divided into four groups: Control (CTR), Exercise (Exe), LPS, and Exercise + LPS (Exe+LPS). Mice from Exe and Exe+LPS groups were trained at low intensity exercise for 60 minutes/day, 3 days/week, during 5 weeks. Intratracheal instillation of LPS (200/mouse) was performed 48 hours after the last physical test in the LPS and Exe+LPS groups. Twenty-four hours after LPS instillation we measured exhaled nitric oxide (NO), respiratory mechanics, and the density of neutrophils in lung tissue. We further analyzed protein leakage, total and differential cell counts and the levels of IL-1, IL-6, KC, IL-10 and TNF- in bronchoalveolar lavage fluid (BALF). IL-6 and IL-10 levels were also evaluated in serum and lung tissue. The expression of glucocorticoid receptors (Gre) and superoxide dismutase (SOD) was analyzed in lung tissue. Enzymatic activity of glutathione peroxidase (GPX), catalase (CAT), glutathione reductase (GR) and SOD was determined in lung homogenates by spectrophotometry. The level of malondialdehyde (MDA) was quantified in lung homogenates. Results: LPS instillation resulted in increased levels of exhaled NO (p<0.01), higher number of total cells and neutrophils in the BALF (p<0.001), higher number of neutrophils in the lung parenchyma (p<0.001), higher values of pulmonary resistance and elastance (p=0.01), increase of protein leakage (p0.02), increase of IL-6 and IL-10 level in serum (p<0.02) and increase in IL-1, IL-6 and KC levels in BALF (p0.005), compared to the CTR group. Aerobic exercise (Exe+LPS group) resulted in significantly lower exhaled NO levels (p=0.006), lower density of neutrophils in the lung parenchyma (p=0.004), lower pulmonary resistance and elastance values (p = 0.003), increased expression of IL-6, IL-10 and Gre in lung tissue (p0.04) and increased IL-1 level in BALF (p=0.04) compared to the LPS group. Conclusion: Our results show that exercise plays an important role in protecting the lung from the inflammatory effects of LPS-induced ALI. The effects of exercise are mainly mediated by the increased expression of anti-inflammatory cytokines, suggesting that aerobic preconditioning can modulate the inflammatory-anti-inflammatory balance in the early phase of ARDS.

Previous research has shown that chronic exercise positively impacts body image in women. Research defining the modality that yields the best results following an acute session of exercise has yet to be determined. This research attempted to show the psychological benefits that exercise could have on female body image after only one bout of exercise. PURPOSE: The purpose of the current study was to examine the effects of three different modalities of acute exercise on state body image in women. This study aimed to determine which modality, if any, is more effective in increasing state body image. METHODS: Twenty-five female participants (20.2 ± 2.2 years; 23.6 ± 4.0 BMI, 25.5 ± 6.0 body fat percent) attended laboratory sessions on six different occasions; the initial informed consent, risk stratification, and descriptive data session, the familiarization session, the three exercise sessions, and the control session. During the familiarization session, each participant was acquainted with each exercise modality. The aerobic (AE) session consisted of a five-minute warm-up, 30 minutes of treadmill exercise, and a five-minute cool-down. The interval circuit (IC) session involved a five-minute warm-up, two circuits containing five bodyweight exercises each, and five minutes of cool-down stretching. The resistance (RE) session included a five-minute warm-up, three sets of eight repetitions of the bench press, bent-over row, overhead press, squat, deadlift, and lunge exercises, and five-minutes of cool-down stretching. The control session included 40 minutes of quiet reading. Ratings of perceived exertion and heart rate were monitored and recorded during each trial. State body image, positive mood, and negative mood were measured immediately before and after each experimental session. RESULTS: Following the AE and RE sessions, state body image significantly improved from pre- to post-session (AE: 5.2 ± 1.2 to 5.7 ± 1.0; RE: 5.4 ± 1.4 to 5.9 ± 1.2; p < 0.05). Only the RE post-session state body image (5.4 ± 1.4) was significantly different from the CO post-session state body image (5.4 ± 1.1; p < 0.05). The AE and RE sessions significantly increased positive mood and decreased negative mood from pre- to post-session (p < 0.05). CONCLUSION: Participation in the aerobic and resistance sessions significantly improved body image from pre- to post-exercise. Resistance exercise was the only research modality that yielded significantly higher post-exercise state body image as compared to the control session. Thus, a single resistance exercise session may help individuals to improve their state body image.

Prevention and treatment of type 2 diabetes mellitus (T2DM), relies heavily on self-care behaviours such as dietary modification, physical activity, and medication adherence. Ability to perform these self-care behaviours depends, at least in part, on executive function (EF). Recent evidence suggests a correlation between T2DM and impaired cognitive function, including EF. Given the importance of EF for regulation of behaviours, and the importance of self-care in diabetes management, attenuated EF would represent a potential barrier to proper disease management. Thus the objective of Study 1 was to examine the association between T2DM and EF through meta-analytic techniques. Medline, PsychoInfo, and Scopus, as well as article references, were used to identify studies comparing individuals with T2DM to a control population. Effect size was calculated using cohen’s d and random effects modeling, and the potential impact of moderators (age, sex, and T2DM duration) were examined. Review of 60 studies (59 articles), revealed a significant, small-to-moderate effect size (d=-0.249, p<0.001) such that those with T2DM have lower EF. This finding was consistent across all aspects of EF examined (verbal fluency, mental flexibility, inhibition, working memory, and attention), and the association was stronger for those with shorter disease duration. The findings of study 1 illustrate that although individuals with T2DM have a great need for EF, as evidenced by the reliance of self-care behaviours on EF, this population has lower EF upon which to draw to perform these behaviours. Thus, strategies that improve EF, such as aerobic exercise, may be particularly relevant to this population. Acute aerobic exercise has been shown to improve EF in young and older adults; however this effect had not yet been examined in individuals with T2DM. Thus the objective of Study 2 was to examine the effects of acute aerobic exercise on EF in adults with T2DM. A within-subject design was used to compare the change in EF task performance following moderate and minimal intensity aerobic exercise, using Stroop and GNG to measure EF. Analysis revealed a significant effect of moderate exercise in women (but not men) and recently active (but not inactive) individuals, such that moderate exercise mitigated the self-regulatory fatigue effect observed following exercise. This study provides preliminary evidence of a significant beneficial effect of moderate aerobic exercise on EF in female and recently active adults with T2DM.

Aerobic exercise interventions involving individuals with type 1 diabetes have had little positive effect on blood glucose control as reflected by hemoglobin A1c. The few existing interventions involving resistance exercise, either alone or combined with aerobic exercise, while small in sample size, have had better outcomes. The purpose of this research program was to examine the changes in blood glucose levels during activity and for 24 hours post-exercise (as measured by continuous glucose monitoring) when resistance exercise is performed, either on its own or combined with aerobic exercise, as compared to aerobic exercise alone or no exercise. Twelve physically active individuals with type 1 diabetes performed 5 separate exercise sessions in random order separated by at least five days: 1) no exercise/control; 2) aerobic exercise (45 minutes of treadmill running at 60% VO2peak); 3) resistance exercise (45 minutes of weight lifting – 3 sets of 8 repetitions of 7 different exercises); 4) aerobic then resistance exercise (2 and 3 combined with the aerobic exercise first); 5) resistance then aerobic exercise (2 and 3 combined with the resistance exercise first). We found that resistance exercise was associated with a lower risk of hypoglycemia during exercise, less carbohydrate intake during exercise, less post-exercise hyperglycemia and more frequent (but less severe) nocturnal hypoglycemia than aerobic exercise. When aerobic and resistance exercise were combined, performing resistance exercise prior to aerobic exercise (rather than the reverse) resulted in attenuated declines in blood glucose during aerobic exercise, accompanied by a lower need for carbohydrate supplementation during exercise and a trend towards milder post-exercise nocturnal hypoglycemia.

No description available.

O dano muscular induzido pelo exercício (DMIE) é um fenômeno que ocorre ao realizarmos um exercício com o qual não estamos habituados, seja pela modalidade, volume ou intensidade. Além disso, esta condição está fortemente relacionada com contrações excêntricas ou gestos que predominantemente envolvam este tipo de contração, causando prejuízos funcionais importantes e diminuindo o desempenho. Diante disto, estratégias para acelerar o processo de recuperação muscular vem sendo investigadas. Dentre elas, a recuperação ativa, técnica muito utilizada no meio prático e que consiste na execução de exercícios com intensidade baixa ou moderada buscando melhorar a recuperação após uma sessão de treino mais intensa. No entanto, nenhum estudo comparou duas formas de recuperação ativa com exercícios aeróbios até o momento, além dos estudos experimentais da área apresentarem qualidade metodológica frágil. Com isso, o objetivo desta dissertação é comparar o efeito da recuperação ativa em esteira e em cicloergômetro sobre marcadores de dano muscular. Para isso, trinta voluntários do sexo masculino foram alocados de forma randomizada em três grupos: grupo esteira (GE, n = 10), grupo cicloergômetro (GCI, n = 10) e grupo controle (GC, n = 10). Avaliações da contração isométrica voluntária máxima (CIVM), dor, concentração plasmática de creatina kinase (CK) e lactato desidrogenase (LDH) e espessura e ecogenicidade dos músculos reto femoral (RF) e vasto lateral (VL) foram realizadas pré, 24h, 48h e 72h após um protocolo indutor de dano muscular, constituído por cinco séries de 10 contrações excêntricas máximas em dinamômetro isocinético. Após o protocolo indutor de dano muscular, os sujeitos realizaram a intervenção de acordo com o grupo em que foram alocados, com duração de 30 minutos e intensidade de 60% do VO2máx, independente da modalidade. Não foram observadas diferenças significativas entre os grupos nos parâmetros de caracterização da amostra. Não houve diferença significativa entre os grupos em todas as variáveis analisadas. Houve redução significativa no torque nos períodos imediatamente após (IP), 24h, 48h e 72h comparado ao período Pré em todos os grupos. Houve aumento significativo da dor nos períodos 24h, 48h e 72h comparado ao período Pré em todos os grupos. Houve aumento significativo na espessura do músculo RF 24h após o protocolo de dano muscular. A ecogenicidade foi maior tanto no RF quanto no VL nos períodos de 48h e 72h quando comparada ao período Pré. Não houve diferença significativa nas concentrações plasmáticas de CK e LDH entre os períodos de avaliação. Os resultados do presente estudo permitem concluir que a execução de recuperação ativa nos parâmetros adotados, seja em cicloergômetro ou esteira, não modifica o processo de recuperação após dano muscular. / The exercise-induced muscle damage (EIMD) is a phenomenon that occurs when we execute an unusual exercise, either by type, volume or intensity. Furthermore, this condition is strongly associated with eccentric contractions or gestures which predominantly involve this type of contraction, causing significant loss of function and decreasing performance. In view of this, the search for strategies to accelerate muscle recovery process has been investigated. Among them, active recovery, technique widely used in practical means and which consists in carrying out exercises with low or moderate intensity seeking to improve recovery after a more intense training session. However, no studies have compared two types of active recovery yet, besides the experimental studies presented fragile methodological quality. Thus, the aim of this study is to compare the effect of active recovery on a treadmill and cycle ergometer on muscle damage markers. For this, thirty male volunteers were randomly divided into three groups: treadmill group (EG, n = 10), cycle ergometer group (GCI, n = 10) and control group (CG, n = 10). Evaluations of maximal voluntary isometric contraction (MVIC), pain, plasma concentration of creatine kinase (CK) and lactate dehydrogenase (LDH) and muscle thickness and echo intensity of the rectus femoris (RF) and vastus lateralis (VL) were performed before, 24h, 48h and 72h after the muscle damage protocol, comprising five sets of 10 maximum eccentric contractions using an isokinetic dynamometer. After muscle damage protocol, the subjects performed the intervention according to the group they were allocated, lasting 30 minutes with an intensity of 60% VO2max, regardless of the type. Significant differences between the groups in the sample characterization parameters were observed. There was no significant difference between groups in all variables. There was a significant reduction in torque in the periods immediately after (IP), 24h, 48h and 72h compared to the Pre period in all groups. There was a significant increase in pain at times 24h, 48h and 72h compared to the Pre period in all groups. A significant increase in muscle thickness of RF was observed in 24h period. The echo intensity was higher in both RF and VL in periods of 48h and 72h compared to the Pre period. There was no significant difference in plasma concentrations of CK and LDH between the evaluation periods. Our results illustrate that the performance of active recovery, in the adopted parameters, either in cycle ergometer or treadmill, does not change the process of recovery after muscle damage.

This abstract will provide a brief overview of the following literature review. Alzheimer’s disease (AD) is the most common cause of dementia, and is a rapidly growing public health concern, as an increasing number of the world’s population is living well beyond 65 years of age. Alzheimer’s Disease is a progressive neurodegenerative condition, first presenting with mild memory impairment, and advancing over the course of years to profound memory loss, complete immobility, lack of speech and facial recognition. Currently, only palliative treatments are available to delay the progression of the disease, and lessen the severity of the cognitive impairment. However, until a cure is available, researchers and physicians have turned their attention to alternate therapies, one of the most important being exercise. Research efforts have now turned to examining the relationship between the positive physiological responses to exercise, and attenuation of the classic neurodegenerative patterns in patients with AD. The current study examined the effects of aerobic exercise, strength training and resistance-based exercise, and multimodal exercise (containing both of the aforementioned exercise modalities) on the physical and mental/cognitive health of patients with mild cognitive impairment (MCI) and AD. Thus far, exercise therapy has proven to be of great potential value as a supplement to pharmacological treatment, as well as a stand-alone prescription for patients with a milder form of cognitive impairment due to the onset of a neurodegenerative condition. The benefits can be grouped into two categories, cognitive and physiological. The effects on cognitive function range from improved memory to increased independence in activities of daily living, and the physiological effects range from improved clearance of amyloid beta plaques in the brain, to reduction of neuroinflammatory processes. The available research on this subject is extensive, covering a variety of exercise modalities at different intensities, and taking into consideration effects on individuals with MCI, early AD, and advanced AD. The general consensus is that continued, long-term adherence to an appropriate exercise routine can delay cognitive decline, and help patients with neurodegenerative diseases to live independently for a longer period of time. The improvements in cognition, memory, immediate recognition, and other related cognitive functions are mostly attributed to the heightened health of the brain tissue and neural circuitry due to exercise. Exercise (mainly aerobic) enhances cerebral blood flow, improves cardiovascular health, reduces the risk for type 2 diabetes mellitus, and has several other important effects that prevent the formation of pathological biomarkers of AD and promote neurogenesis. Atrophy of regions such as the hippocampus, amygdala, and cerebral cortex can be prevented, and reversed to a certain extent, as a result of long-term exercise therapy. The results of current research could assist physicians and caregivers to provide the appropriate type and intensity of exercise to patients with early, intermediate, and advanced stages of Alzheimer’s disease. Proactive exercise therapy for individuals with a known family history of neurodegenerative disease may help to maintain brain volume, specifically in the hippocampus, and reduce the risk of severe cognitive impairment. Future directions for research include examining the combined effects of pharmacological treatment and exercise therapy, and determining the average amount of time by which exercise delays the progression of early stage cognitive impairment to advanced impairment. Key Terms: aerobic exercise, Alzheimer’s disease, amyloid plaque, hippocampus, mild cognitive impairment, neurodegeneration, neurofibrillary tangle

This thesis presents four studies investigating the phenomenon of post exercise hypotension in the human condition of pre (borderline)-hypertension. Study one investigated the effects of an acute bout of 30-minutes upright cycling on post exercise haemodynamics and compared the results to a non-exercise control condition. 9 pre-hypertensive males, mean arterial pressure (MAP) = 106 ± 5 mmHg (50 ± 10 yr), not on medication, were studied for 6 hours following 30-minutes of cycle exercise at 70% maximal oxygen consumption and following 30-minutes of seated rest. Results demonstrate that moderate intensity exercise exerts a modest fall (~6 mmHg) in arterial pressure with the hypotension sustained for 6-hours post exercise. The fall in arterial pressure equates to a significantly reduced after load when compared to both pre-exercise baseline and non-exercise control data taken at the same time of day. The arterial pressure responses transcended into a sustained reduction (20%) in systemic vascular resistance and reciprocal increase in vascular conductance for up to 2-hours post-exercise. Venous atrial natriuretic peptide (ANP) demonstrated an elevation (44%) following exercise and a significant decline (33%) in the post-exercise period mirroring the haemodynamic response. This research reveals that acute exercise is capable of sustained reductions in arterial pressure and vascular resistance beyond the usual labile fluctuations and that the octapeptide ANP may exert a modulatory influence over the post-exercise response. Increases in 02 tension beyond the physiological range induces complex effects on the circulatory system with a dominant vasoconstriction following hyperoxia. The purpose of study 2 was to assess the effects of hypoxic (16% 02) and hyperoxic (50% 62) exercise on subsequent haemodynamic control when compared with normoxia. 9 pre-hypertensive males, MAP = 106 ± 5 mmHg (50 ±10 yr), not on medication, performed 30-minutes of cycle exercise at 70% normoxic maximal oxygen consumption in hypoxia (16% O 2 ), hyperoxia (50% O 2) and normoxia(21% O2 ). Hyperoxic exercise blunted post-exercise haemodynamics by significantly attenuating the reductions (from normoxic baseline) in SVR (-45%, PO.05 vs. normoxic & hypoxic exercise immediately post-exercise) that persisted throughout 120-minutes recovery in normoxia (-35% vs. normoxic & hypoxic exercise, during recovery) and elicited a mildly hypertensive effect, with regards to MAP, whereas normoxic and hypoxic exercise elicited a hypotension compared to baseline (P < 0.05). Circulating ANP was decreased in the hyperoxic trial when compared with normoxic and hypoxic exercise [24.3 (13.4) v. 31.5 (16.3) and 29.6 (13.9) pg/ml, respectively; P < 0.05, pooled for state]. Changes in MAP were related to changes in ANP concentration only following hyperoxic exercise (r = 0.50, P < 0.01). These findings indicate that acute modest hyperoxia reflexively induces measurable physiological derangement partly explained by decreased circulating concentrations of ANP. Study three determined the role of free-radical mediated oxidative stress and redox regulation of circulating NO metabolism as a primary modulator of vascular tone following exercise in pre-hypertensive humans. Utilising the same cohort and exercise protocol as in study 1 venous blood was sampled from an antecubital vein. Plasma NO metabolites nitrate (NO" 3 ) and nitrite (NO"2 ) were determined fluorometrically, whilst S-Nitrosothiol (RSNO) concentrations were assayed by the Saville reaction Indirect markers of oxidative stress were determined spectrophotometrically detecting lipid hydroperoxides (LOOH). Exercise led to a delayed increase in LOOH by 60- minutes post-exercise (0.69 ± 0.13 v. 0.86 ± 0.18 umol/1, respectively, P < 0.05), that remained elevated until termination of the trial 6-hours post-exercise. NO'a significantly fell below baseline by 120-minutes post-exercise (10.8 ± 3.3 v. 1.1 ±1.1 u.mol/1, respectively, P < 0.05), remaining attenuated for the remainder of the study.NO'i and RSNO were unmodified in the post-exercise period. In parallel to this finding the data also indicates a significant blunting in the hyperaemic response [SVR decreased from a 31% reduction immediately (within 1-minute) post-exercise to -13 and 8% at 60- and 120-minutes post-exercise, respectively, P < 0.05] and reversal of the hypotension (P < 0.05) over the same time frame as the augmented lipid peroxidation and attenuated circulating NO~3. These results indicate that augmented oxidative stress exerts a deleterious effect on post-exercise haemodynamics and implicates a potential redox regulation pathway of NO as being a mechanism by which free radical-induced oxidative stress blunts the degree of PEH in the recovery period. The final study investigated the potential role of a redox-mediated regulation of circulating NO bioavailability as a modulator of the augmented vasoconstriction following hyperoxic exercise. The same cohort and exercise protocol were employed as in study 2 and venous blood was assayed for NO"3 , NO'a, RSNO, LOOK, & lipid /water-soluble antioxidant concentrations. Similar adverse haemodynamic effects were noted following hyperoxic exercise as reported previously in study 2. RSNO showed a significant increase following hypoxic exercise only (P < Q.Q5, state x time, interaction), whereas NO~3, NO~2 and LOOH failed to differ between conditions (P > 0.05, main effect for state [02] and state x time, interaction effects). Ascorbic acid was mobilised in response to hyperoxic exercise when compared to normoxia (P < 0.05, main effect for state [O2] and state x time, interaction effects) being significantly elevated by 120-minutes post-exercise in hyperoxia compared to normoxia and hypoxia [75.1 (31) v. 39.5 (18.3) v. 46.7 (14.2) |amol/l, respectively, P < 0.05]. This data demonstrates an effective endogenous antioxidant response and argues against a redox regulation pathway of NO metabolism as a primary mediator of blunted vasodilatation in this scenario. This elucidates a more complex regulation of arterial tone, resulting from a metabolic pathway independent of NO in older subjects with pre-hypertension. This work demonstrates that (1) aerobic exercise exerts a hypotensive effect in humans with pre-hypertension, (2) ANP plays a part in the vasodilatation following exercise, (3) Free-radical mediated oxidative stress & subsequent modulation of NO metabolism exerts a deleterious influence on post-exercise haemodynamics (4) Acute hyperoxic exercise induces a sustained vasoconstriction that is mediated via circulating ANP concentration but not by redox regulation of NO metabolism.