34 research outputs found

    Elevated salivary C-reactive protein predicted by low cardio-respiratory fitness and being overweight in African children

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    INTRODUCTION: C-reactive protein (CRP) is a sensitive marker of systemic inflammation and is an independent risk factor for cardiovascular disease. The aim of the study was to examine the relationship between salivary CRP, cardio-respiratory fitness and body composition in a paediatric population. METHODS: This was a cross-sectional study of 170 black South African children (age 9.41 ± 1.55 years, 100 females, 70 males) in grades 3 to 7. Unstimulated whole saliva samples were obtained for the analysis of CRP. Height, mass, skin-fold thickness, resting blood pressure, and waist and hip circumference measurements were obtained. Cardio-respiratory fitness was assessed using a 20-m multi-stage shuttle run. Children were classified as overweight/obese according to the Center for Disease Control and Prevention (CDC) body mass index (BMI) percentile ranking, and meeting percentage body fat recommendations, if percentage body fat was ≤ 25% in boys and ≤ 32% in girls. The cut-off point for low cardio-respiratory fitness was a predicted aerobic capacity value ≤ the 50th percentile for the group. Contributions of low cardio-respiratory fitness, overweight/obesity, and not meeting percentage body fat recommendations, to elevated salivary CRP (≥ 75th percentile) concentration and secretion rate were examined using binary logistic regression analysis with a backward stepwise selection technique based on likelihood ratios. RESULTS: Poor cardio-respiratory fitness was independently associated with elevated salivary CRP concentration (OR 3.9, 95% CI: 1.7–8.9, p = 0.001). Poor cardio-respiratory fitness (OR 2.7, 95% CI: 1.2–6.1, p = 0.02) and overweight/obesity (BMI ≥ 85th percentile) (OR 2.5, 95% CI: 1.1–5.9, p = 0.03) were independent predictors of elevated salivary CRP secretion rate. CONCLUSION: The results suggest a strong association between poor cardio-respiratory fitness and/or overweight/obesity and inflammatory status in children, based on elevated salivary CRP levels

    Changes in neutrophil count, creatine kinases and muscle soreness after repeated bouts of downhill running

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    Objective. A primary objective was to examine circulating neutrophil count after repeated bouts of downhill running. An additional aim was to determine creatine kinase (CK) levels during the initial 12 hours, after repeated DHRs. Design. Eleven healthy, untrained Caucasian males performed 2 x 60 min bouts of DHR (-13.5%), spaced 14 days apart, at a speed equal to 75% VO2max on a level grade. Blood was collected before, after, and every hour for 12 hours, and every 24 hours for 6 days. Absolute neutrophil count, CK, and delayed-onset muscle soreness (DOMS) were assessed. Results were analysed using repeated measures ANOVA (

    Changes in neutrophil count, creatine kinases and muscle soreness after repeated bouts of downhill running

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    Objective. A primary objective was to examine circulating neutrophil count after repeated bouts of downhill running. An additional aim was to determine creatine kinase (CK) levels during the initial 12 hours, after repeated DHRs. Design. Eleven healthy, untrained Caucasian males performed 2 x 60 min bouts of DHR (-13.5%), spaced 14 days apart, at a speed equal to 75% VO2max on a level grade. Blood was collected before, after, and every hour for 12 hours, and every 24 hours for 6 days. Absolute neutrophil count, CK, and delayed-onset muscle soreness (DOMS) were assessed. Results were analysed using repeated measures ANOVA (

    Changes in neutrophil count, creatine kinases and muscle soreness after repeated bouts of downhill running

    Get PDF
    Objective. A primary objective was to examine circulating neutrophil count after repeated bouts of downhill running. An additional aim was to determine creatine kinase (CK) levels during the initial 12 hours, after repeated DHRs. Design. Eleven healthy, untrained Caucasian males performed 2 x 60 min bouts of DHR (-13.5%), spaced 14 days apart, at a speed equal to 75% VO2max on a level grade. Blood was collected before, after, and every hour for 12 hours, and every 24 hours for 6 days. Absolute neutrophil count, CK, and delayed-onset muscle soreness (DOMS) were assessed. Results were analysed using repeated measures ANOVA (

    Consensus on a video analysis framework of descriptors and definitions by the Rugby Union Video Analysis Consensus group

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    Using an expert consensus-based approach, a rugby union Video Analysis Consensus (RUVAC) group was formed to develop a framework for video analysis research in rugby union. The aim of the framework is to improve the consistency of video analysis work in rugby union and help enhance the overall quality of future research in the sport. To reach consensus, a systematic review and Delphi method study design was used. After a systematic search of the literature, 17 articles were used to develop the final framework that described and defined key actions and events in rugby union (rugby). Thereafter, a group of researchers and practitioners with experience and expertise in rugby video analysis formed the RUVAC group. Each member of the group examined the framework of descriptors and definitions and rated their level of agreement on a 5-point agreement Likert scale (1: strongly disagree; 2: disagree; 3: neitheragree or disagree; 4: agree; 5: strongly agree). The mean rating of agreement on the five-point scale (1: strongly disagree; 5: strongly agree) was 4.6 (4.3–4.9), 4.6 (4.4–4.9), 4.7 (4.5–4.9), 4.8 (4.6–5.0) and 4.8 (4.6–5.0) for the tackle, ruck, scrum, line-out and maul, respectively. The RUVAC group recommends using this consensus as the starting framework when conducting rugby video analysis research. Which variables to use (if not all) depends on the objectives of the study. Furthermore, the intention of this consensus is to help integrate video data with other data (eg, injury surveillance)

    Current and Historical Drivers of Landscape Genetic Structure Differ in Core and Peripheral Salamander Populations

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    With predicted decreases in genetic diversity and greater genetic differentiation at range peripheries relative to their cores, it can be difficult to distinguish between the roles of current disturbance versus historic processes in shaping contemporary genetic patterns. To address this problem, we test for differences in historic demography and landscape genetic structure of coastal giant salamanders (Dicamptodon tenebrosus) in two core regions (Washington State, United States) versus the species' northern peripheral region (British Columbia, Canada) where the species is listed as threatened. Coalescent-based demographic simulations were consistent with a pattern of post-glacial range expansion, with both ancestral and current estimates of effective population size being much larger within the core region relative to the periphery. However, contrary to predictions of recent human-induced population decline in the less genetically diverse peripheral region, there was no genetic signature of population size change. Effects of current demographic processes on genetic structure were evident using a resistance-based landscape genetics approach. Among core populations, genetic structure was best explained by length of the growing season and isolation by resistance (i.e. a ‘flat’ landscape), but at the periphery, topography (slope and elevation) had the greatest influence on genetic structure. Although reduced genetic variation at the range periphery of D. tenebrosus appears to be largely the result of biogeographical history rather than recent impacts, our analyses suggest that inherent landscape features act to alter dispersal pathways uniquely in different parts of the species' geographic range, with implications for habitat management

    Airways inflammatory and atopy-related responses in athletes

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    The prevalence of asthma and airway hyperresponsiveness (AHR) in highly trained endurance athletes is rising. The type of training (i.e. endurance, or speed and power) seems to influence the airway symptoms. High-intensity exercise and training might contribute to the development of asthma or AHR in athletes previously unaffected by these airway disorders. Repeated hyperventilation of unconditioned air, as well as air containing irritants and/or allergens has been suggested to cause thermal, mechanical, or osmotic airway trauma resulting in damage to the airway epithelium. Subsequent airway inflammatory responses may be responsible for the development of atopy-related symptoms in endurance athletes such as those observed in asthma and AHR. Eosinophils and neutrophils are the inflammatory cells that have been frequently observed to be elevated in the airways of endurance athletes. The trafficking of these cells to the airways may possibly be regulated by TH2 cytokines that are expressed in the airways in response to epithelial cell damage. In addition, these airway inflammatory responses may lead to airway remodelling similar to that which occurs in asthma. The effect of the exercise challenge itself may initiate airway atopy-related and inflammatory responses in endurance athletes. While the literature seems to support the role of local airway conditions and/or events in inducing atopy-related symptoms in athletes, it is proposed that alterations in the hormonal and/or cytokine milieu with intense competition and/or training may also play a role. South African Journal of Sports Medicine Vol. 18 (2) 2006: pp. 46-5
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