Investigation of JAK/STAT signaling in human skeletal muscle

Understanding muscle adaptation and repair is vital for preserving muscle loss with aging. Analysis of the inflammatory-responsive signalling pathway, JAK/STAT was performed. After intense exercise, the STAT3 pathway is highly activated, potentially by the pro-inflammatory regulator IL-6. This pathway is suppressed in older individuals, possible leading to altered inflammatory regulation.

Glycogen-protein associations in human skeletal muscle

The collective findings of this dissertation demonstrated little effect of exercise on the absolute or relative expression of glycogen regulatory proteins associated with a glycogen enriched fraction in human skeletal muscle. However the findings of this thesis help inform methodological approaches to future investigations into glycogen-protein associations.

Chemoattractive myokines

Chemoattractive myokines are inflammatory molecules released from muscle that are important in muscle repair and recovery. Exercise increased these factors, enabling the infiltration of immune cells, while ageing blunted this response. This work provides new insights into the complex regulation of inflammatory responses that are important for growth and function.

Physiological and biomechanical responses to walking underwater on a non-motorised treadmill: Effects of different exercise intensities and depths in middle-aged healthy women

Non-motorised underwater treadmills are commonly used in fitness activities. However, no studies have examined physiological and biomechanical responses of walking on non-motorised treadmills at different intensities and depths. Fifteen middle-aged healthy women underwent two underwater walking tests at two different depths, immersed either up to the xiphoid process (deep water) or the iliac crest (shallow water), at 100, 110, 120, 130 step-per-minute (spm). Oxygen consumption (VO2), heart rate (HR), blood lactate concentration, perceived exertion and step length were determined. Compared to deep water, walking in shallow water exhibited, at all intensities, significantly higher VO2 (+13.5%, on average) and HR (+8.1%, on average) responses. Water depth did not influence lactate concentration, whereas perceived exertion was higher in shallow compared to deep water, solely at 120 (+40%) and 130 (+39.4%) spm. Average step length was reduced as the intensity increased (from 100 to 130 spm), irrespective of water depth. Expressed as a percentage of maximum, average VO2 and HR were: 64���76% of peak VO2 and 71���90% of maximum HR, respectively at both water depths. Accordingly, this form of exercise can be included in the ���vigorous��� range of exercise intensity, at any of the step frequencies used in this study.

Women in exercise to music : individual experiences of influences to be slim

This qualitative study explores reasons why women who participate in exercise to music continue to do so long-term. Thirteen women were interviewed. Generational differences of body perceptions were easily identifiable.

Exercise and Mood: Exploring the Role of Exercise in Regulating Stress Reactivity in Bipolar Disorder

Bipolar Disorder (BD) is a recurrent and debilitating psychological disorder characterized by a chronic dysregulation of mood with fluctuations between extremely low (e.g., depression) and extremely elevated mood states (e.g., mania), and ranks as the 6th leading cause of disability in the world. Although research has consistently shown that exercise may have antidepressant and stress-attenuating benefits in other psychiatric illnesses (e.g., depression, anxiety), these benefits have not been directly investigated for BD. The current study represents the first known investigation to examine this relationship. Single-participant designs, with crossover and interaction treatment components (i.e., A/B/A/B/A, A/C/A/C/A, A/B/A/C/A, or A/C/A/B/A) were utilized to investigate the impact of participation in a prescribed regimen of exercise (EP) versus standard behavioral activation (SBA; i.e., non-exercise activity) has on stress perception and reactivity, and mood stability in a sample of individuals with BD. Individuals completed four total weeks of treatment, and psychophysiological measures of reactivity were recorded during a laboratory stress task (i.e., backward counting task) prior to and following each two-week intervention phase. No appreciable differences were found between levels of exercise participation between treatment groups. Interestingly, symptoms of depressed mood (BDI-II scores) decreased at similar rates following 4 weeks of treatment for all participants. BDI-II decreases were found to be most correlated with elective exercise participation, although this relationship was not significant. Regarding stress reactivity, elective participation in mild to moderate intensity exercise was found to reduce an individual���s perception of stress reactivity to an acute stressor, while participation in a prescribed program of exercise was more effective in reducing physiological response to the same task. Utilizing multiple forms of behavioral activation simultaneously was found to be most effective in decreasing perception of stress reactivity, and may also result in a positive change in the use of adaptive versus maladaptive coping strategies. Participation in a 4-week program of exercise appeared to provide the most benefit, consistent with exercise habituation theories. Overall, current findings provide preliminary support for the prophylactic benefits of including a prescribed and monitored program of exercise as an adjunct treatment for individuals with BD. Larger scale research is needed to more clearly determine the impact of exercise on stress reactivity and mood episode relapse in individuals with BD.

Ibuprofen supplementation and its effects on NF-KB activation in skeletal muscle following resistance exercise

Resistance exercise triggers a subclinical inflammatory response that plays a pivotal role in skeletal muscle regeneration. Nuclear factor�����B (NF�����B) is a stress signalling transcription factor that regulates acute and chronic states of inflammation. The classical NF�����B pathway regulates the early activation of post���exercise inflammation; however there remains scope for this complex transcription factor to play a more detailed role in post���exercise muscle recovery. Sixteen volunteers completed a bout of lower body resistance exercise with the ingestion of three 400 mg doses of ibuprofen or a placebo control. Muscle biopsy samples were obtained prior to exercise and at 0, 3 and 24 h post���exercise and analysed for key markers of NF�����B activity. Phosphorylated p65 protein expression and p65 inflammatory target genes were elevated immediately post���exercise independent of the two treatments. These changes did not translate to an increase in p65 DNA binding activity. NF�����B p50 protein expression and NF�����B p50 binding activity were lower than pre���exercise at 0 and 3 h post���exercise, but were elevated at 24 h post���exercise. These findings provide novel evidence that two distinct NF�����B pathways are active in skeletal muscle after resistance exercise. The initial wave of activity involving p65 resembles the classical pathway and is associated with the onset of an acute inflammatory response. The second wave of NF�����B activity comprises the p50 subunit, which has been previously shown to resolve an acute inflammatory program. The current study showed no effect of the ibuprofen treatment on markers of the NF�����B pathway, however examination of the within group effects of the exercise protocol suggests that this pathway warrants further research.

Influence of nitrogen salts on growth and physiological responses of Rhizophora apiculata Blume in non-aerated water culture

Influence of two different forms of nitrogen on growth and physiological aspects of water-cultured seedlings of Rhizophora apiculata was studied. Of the two forms of nitrogen supplied to the growth medium, ammonium nitrogen was better than nitrate nitrogen by exhibiting increased dry matter production, shoot length, leaf area and also enhanced the contents of carotenoids, chlorophylls and their presence in photosystems and light harvesting protein complex.

The influence of recreational ball hockey play on cardiovascular risk factors in sedentary males

Introduction: The prevalence of coronary artery disease (CAD) is ever increasing in western industrialized societies. An individuals overall risk for CAD may be quantified by integrating a number of factors including, but not limited to, cardiorespiratory fitness, body composition, blood lipid profile and blood pressure. It might be expected that interventions aimed at improving any or all of these independent factors might improve an individual 's overall risk. To this end, the influence of standard endurance type exercise on cardiorespiratory fitness, body composition, blood lipids and blood pressure, and by extension the reduction of coronary risk factors, is well documented. On the other hand, interval training (IT) has been shown to provide an extremely powerful stimulus for improving indices of cardiorespiratory function but the influence of this training type on coronary risk factors is unknown. Moreover, the vast majority of studies investigating the effects of IT on fitness have used laboratory type training protocols. As a result of this, the influence of participation in interval-type recreational sports on cardiorespiratory fitness and coronary risk factors is unknown. Aims: The aim of the present study was to evaluate the effectiveness of recreational ball hockey, a sport associated with interval-type activity patterns, on indices of aerobic function and coronary risk factors in sedentary men in the approximate age range of 30 - 60 years. Individual risk factors were compiled into an overall coronary risk factor score using the Framingham Point Scale (FPS). Methods: Twenty-four sedentary males (age range 30 - 60) participated in the study. Subject activity level was assessed apriori using questionnaire responses. All subjects (experimental and control) were assessed to have been inactive and sedentary prior to participation in the study. The experimental group (43 �� 3 years; 90 �� 3 kg) (n = 11) participated in one season of recreational ball hockey (our surrogate for IT). Member of this group played a total of 16 games during an 11 week span. During this time, the control group (43 �� 2 years; 89 �� 2 kg) (n = 11) performed no training and continued with their sedentary lifestyle. Prior to and following the ball hockey season, experimental and control subjects were tested for the following variables: 1) cardiorespiratory fitness (as V02 Max) 2) blood lipid profile 3) body composition 5) waist to hip ratio 6) blood glucose levels and 7) blood pressure. Subject V02 Max was assessed using the Rockport submaximal walking test on an indoor track. To assess body composition we determined body mass ratio (BMI), % body fat, % lean body mass and waist to hip ratio. The blood lipid profile included high density lipoprotein, low density lipoprotein and total cholesterol levels; in addition, the ratio of total cholesterol to high density was calculated. Blood triglycerides were also assessed. All data were analyzed using independent t - tests and all data are expressed as mean �� standard error. Statistical significance was accepted at p :S 0.05. Results: Pre-test values for all variables were similar between the experimental and control group. Moreover, although the intervention used in this study was associated with changes in some variables for subjects in the experimental group, subjects in the control group did not exhibit any changes over the same time period. BODY COMPOSITION: The % body fat of experimental subjects decreased by 4.6 �� 0.5%, from 28.1 �� 2.6 to 26.9 �� 2.5 % while that of the control group was unchanged at 22.7 �� 1.4 and 22.2 �� 1.3 %. However, lean body mass of experimental and control subjects did not change at 64.3 �� 1.3 versus 66.1 �� 1.3 kg and 65.5 �� 0.8 versus 64.7 �� 0.8 kg, respectively. In terms of body mass index and waist to hip ratio, neither the experimental nor the control group showed any significant change. Respective values for the waist to hip ratio and body mass index (pre and post) were as follows: 1 �� 0.1 vs 0.9 �� 0.1 (experimental) and 0.9 �� 0.1 versus 0.9 �� 0.1 (controls) while for BMI they were 29 �� 1.4 versus 29 �� 1.2 (experimental) and 26 �� 0.7 vs. 26 �� 0.7 (controls). CARDIORESPIRATORY FITNESS: In the experimental group, predicted values for absolute V02 Max increased by 10 �� 3% (i.e. 3.3 �� 0.1 to 3.6 �� 0.1 liters min -1 while that of control subjects did not change (3.4 �� 0.2 and 3.4 �� 0.2 liters min-I). In terms of relative values for V02 Max, the experimental group increased by 11 �� 2% (37 �� 1.4 to 41 �� 1.4 ml kg-l min-I) while that of control subjects did not change (41 �� 1.4 and 40 �� 1.4 ml kg-l min-I). BLOOD LIPIDS: Compared to pre-test values, post-test values for HDL were decreased by 14 �� 5 % in the experiment group (from 52.4 �� 4.4 to 45.2 �� 4.3 mg dl-l) while HDL data for the control group was unchanged (49.7 �� 3.6 and 48.3 �� 4.1 mg dl-l, respectively. On the other hand, LDL levels did not change for either the experimental or control group (110.2 �� 10.4 versus 112.3 �� 7.1 mg dl-1 and 106.1 �� 11.3 versus 127 �� 15.1 mg dl-1, respectively). Further, total cholesterol did not change in either the experimental or control group (181.3 �� 8.7 mg dl-1 versus 178.7�� 4.9 mg dl-l) and 190.7 �� 12.2 versus 197.1 �� 16.1 mg dl-1, respectively). Similarly, the ratio of TC/HDL did not change for either the experimental or control group (3.8 �� 0.4 versus 4.5 �� 0.5 and 4 �� 0.4 versus 4.2 �� 0.4, respectively). Blood triglyceride levels were also not altered in either the experimental or control group (100.3 �� 19.6 versus 114.8 �� 15.3 mg dl-1 and 140 �� 23.5 versus 137.3 �� 17.9 mg dl-l, respectively). BLOOD GLUCOSE: Fasted blood glucose levels did not change in either the experimental or control group. Pre- and post-values for experimental and control groups were 92.5 �� 4.8 versus 93.3 �� 4.3 mg dl-l and 92.3 �� 11.3 versus 93.2 �� 2.6 mg dl-1 , respectively. BLOOD PRESSURE: No aspect of blood pressure was altered in either the experimental or control group. For example, pre- and post-test systolic blood pressures were 131 �� 2 versus 129 �� 2 mmHg (experimental) and 123 �� 2 and 125 �� 2 mmHg (controls), respectively. Pre- and post-test diastolic blood pressures were 84 �� 2 and 83 �� 2 mmHg (experimental) and 81 �� 1 versus 82 �� 1 mmHg, respectively. Similarly, calculated pulse pressure was not altered in the experimental or control as pre- and post-test values were 47 �� 1 versus 47 �� 2 mmlHg and 42 �� 2 versus 43 �� 2 mmHg, respectively. FRAMINGHAM POINT SCORE: The concerted changes reported above produced an increased risk in the Framingham Point Score for the subjects in the experimental group. For example, the pre- and post-test FPS increased from 1.4 �� 0.9 to 2.7 �� 0.7. On the other hand, pre- and post-test scores for the control group were 1.8 �� 1 versus 1.8 �� 0.9. Conclusions: Our data confirms previous studies showing that interval-type exercise is a useful intervention for increasing aerobic fitness. Moreover, the increase in V02 Max we found in response to limited participation in ball hockey (i.e. 16 games) suggests that recreational sport may help reduce this aspect of coronary risk in previously sedentary individual. On the other hand, our results showing little or no positive change in body composition, blood lipids or blood pressures suggest that one season of recreational sport in not in of itself a powerful enough stimulus to reduce the overall risk of coronary artery disease. In light of this, it is recommended that, in addition to participation in recreational sport, the performance of regular physical activity is used as an adjunct to provide a more powerful overall stimulus for decreasing coronary risk factors. LIMITATIONS: The increase in the FPS we found for the experimental group, indicative of an increased risk for coronary disease, was largely due to the large decrease in HDL we observed after compared to above one season of ball hockey. In light of the fact that cardiorespiratory fitness was increased and % body fat was decreased, as well as the fact that other parameters such as blood pressure showed positive (but non statistically significant) trends, the possibility that the decrease in HDL showed by our data was anomalous should be considered. FUTURE DIRECTIONS: The results of this study suggesting that recreational sport may be a potentially useful intervention in the reduction of CAD require to be corroborated by future studies specifically employing 1) more rigorous assessment of fitness and fitness change and 2) more prolonged or frequent participants.

The role of physical activity and perceived adequacy on cardiorespiratory fitness in children with developmental coordination disorder

Evidence suggests that children with developmental coordination disorder (DCD) have lower levels of cardiorespiratory fitness (CRF) compared to children without the condition. However, these studies were restricted to field-based methods in order to predict V02 peak in the determination of CRF. Such field tests have been criticised for their ability to provide a valid prediction of V02 peak and vulnerability to psychological aspects in children with DCD, such as low perceived adequacy toward physical activity. Moreover, the contribution of physical activity to the variance in V02 peak between the two groups is unknown. The purpose of our study was to determine the mediating role of physical activity and perceived adequacy towards physical activity on V02 peak in children with significant motor impairments. This prospective case-control design involved 122 (age 12-13 years) children with significant motor impairments (n=61) and healthy matched controls (n=61) based on age, gender and school location. Participants had been previously assessed for motor proficiency and classified as a probable DCD (p-DCD) or healthy control using the movement ABC test. V02 peak was measured by a progressive exercise test on a cycle ergometer. Perceived adequacy was measured using a 7 -item subscale from Children's Selfperception of Adequacy and Predilection for Physical Activity scale. Physical activity was monitored for seven days with the Actical�� accelerometer. Children with p-DCD had significantly lower V02 peak (48.76��7.2 ml/ffm/min; p:50.05) compared to controls (53.12��8.2 ml/ffm/min), even after correcting for fat free mass. Regression analysis demonstrated that perceived adequacy and physical activity were significant mediators in the relationship between p-DCD and V02 peak. In conclusion, using a stringent laboratory assessment, the results of the current study verify the findings of earlier studies, adding low CRF to the list of health consequences associated with DCD. It seems that when testing for CRF in this population, there is a need to consider the psychological barriers associated with their condition. Moreover, strategies to increase physical activity in children with DCD may result in improvement in their CRF.