782 research outputs found

    Training Monitoring for Resistance Exercise: Theory and Applications

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    Resistance exercise is difficult to quantify owing to its inherent complexity with numerous training variables contributing to the training dose (type of exercise, load lifted, training volume, inter-set rest periods, and repetition velocity). In addition, the intensity of resistance training is often inadequately determined as the relative load lifted (% 1-repetition maximum), which does not account for the effects of inter-set recovery periods, repetition velocity, or the number of repetitions performed in each set at a given load. Methods to calculate the volume load associated with resistance training, as well as the perceived intensity of individual sets and entire training sessions have been shown to provide useful information regarding the actual training stimulus. In addition, questionnaires to subjectively assess how athletes are coping with the stressors of training and portable technologies to quantify performance variables such as concentric velocity may also be valuable. However, while several methods have been proposed to quantify resistance training, there is not yet a consensus regarding how these methods can be best implemented and integrated to complement each other. Therefore, the purpose of this review is to provide practical information for strength coaches to highlight effective methods to assess resistance training, and how they can be integrated into a comprehensive monitoring program

    Factors that influence running intensity in interchange players in professional rugby league

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    Background: Rugby league coaches adopt replacement strategies for their interchange players to maximize running intensity; however, it is important to understand the factors that may influence match performance. Purpose: To assess the independent factors affecting running intensity sustained by interchange players during professional rugby league. Methods: Global positioning system (GPS) data were collected from all interchanged players (starters and nonstarters) in a professional rugby league squad across 24 matches of a National Rugby League season. A multilevel mixed-model approach was employed to establish the effect of various technical (attacking and defensive involvements), temporal (bout duration, time in possession, etc), and situational (season phase, recovery cycle, etc) factors on the relative distance covered and average metabolic power (Pmet) during competition. Significant effects were standardized using correlation coefficients, and the likelihood of the effect was described using magnitude-based inferences. Results: Superior intermittent running ability resulted in very likely large increases in both relative distance and Pmet. As the length of a bout increased, both measures of running intensity exhibited a small decrease. There were at least likely small increases in running intensity for matches played after short recovery cycles and against strong opposition. During a bout, the number of collision-based involvements increased running intensity, whereas time in possession and ball time out of play decreased demands. Conclusions: These data demonstrate a complex interaction of individual- and match-based factors that require consideration when developing interchange strategies, and the manipulation of training loads during shorter recovery periods and against stronger opponents may be beneficial

    Acceleration-Based Running Intensities of Professional Rugby League Match-Play

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    Purpose: To quantify the energetic cost of running and acceleration efforts during rugby league competition to aid in prescription and monitoring of training. Methods: Global positioning system (GPS) data were collected from 37 professional rugby league players across 2 seasons. Peak values for relative distance, average acceleration/deceleration, and metabolic power (P<sub>met</sub>) were calculated for 10 different moving-average durations (1–10 min) for each position. A mixed-effects model was used to assess the effect of position for each duration, and individual comparisons were made using a magnitude-based-inference network. Results: There were almost certainly large differences in relative distance and P<sub>met</sub> between the 10-min window and all moving averages <5 min in duration (ES = 1.21–1.88). Fullbacks, halves, and hookers covered greater relative distances than outside backs, edge forwards, and middle forwards for moving averages lasting 2–10 min. Acceleration/deceleration demands were greatest in hookers and halves compared with fullbacks, middle forwards, and outside backs. P<sub>met</sub> was greatest in hookers, halves, and fullbacks compared with middle forwards and outside backs. Conclusions: Competition running intensities varied by both position and moving-average duration. Hookers exhibited the greatest P<sub>met</sub> of all positions, due to high involvement in both attack and defense. Fullbacks also reached high P<sub>met</sub>, possibly due to a greater absolute volume of running. This study provides coaches with match data that can be used for the prescription and monitoring of specific training drills

    Interactions and potential implications of Plasmodium falciparum-hookworm coinfection in different age groups in south-central Côte d'Ivoire

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    BACKGROUND: Given the widespread distribution of Plasmodium and helminth infections, and similarities of ecological requirements for disease transmission, coinfection is a common phenomenon in sub-Saharan Africa and elsewhere in the tropics. Interactions of Plasmodium falciparum and soil-transmitted helminths, including immunological responses and clinical outcomes of the host, need further scientific inquiry. Understanding the complex interactions between these parasitic infections is of public health relevance considering that control measures targeting malaria and helminthiases are going to scale.METHODOLOGY: A cross-sectional survey was carried out in April 2010 in infants, young school-aged children, and young non-pregnant women in south-central Côte d'Ivoire. Stool, urine, and blood samples were collected and subjected to standardized, quality-controlled methods. Soil-transmitted helminth infections were identified and quantified in stool. Finger-prick blood samples were used to determine Plasmodium spp. infection, parasitemia, and hemoglobin concentrations. Iron, vitamin A, riboflavin, and inflammation status were measured in venous blood samples.PRINCIPAL FINDINGS: Multivariate regression analysis revealed specific association between infection and demographic, socioeconomic, host inflammatory and nutritional factors. Non-pregnant women infected with P. falciparum had significantly lower odds of hookworm infection, whilst a significant positive association was found between both parasitic infections in 6- to 8-year-old children. Coinfected children had lower odds of anemia and iron deficiency than their counterparts infected with P. falciparum alone.CONCLUSIONS/SIGNIFICANCE: Our findings suggest that interaction between P. falciparum and light-intensity hookworm infections vary with age and, in school-aged children, may benefit the host through preventing iron deficiency anemia. This observation warrants additional investigation to elucidate the mechanisms and consequences of coinfections, as this information could have important implications when implementing integrated control measures against malaria and helminthiases

    Standardised assessment of personality – a study of validity and reliability in substance abusers

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    <p>Abstract</p> <p>Background</p> <p>Brief screening instruments for co-morbid personality disorders could potentially have great value in substance abuse treatment settings.</p> <p>Methods</p> <p>We assessed the psychometric properties of the 8-item Standardised Assessment of Personality – Abbreviated Scale (SAPAS) in a sample of 58 methadone maintenance patients.</p> <p>Results</p> <p>Internal consistency was modest, but similar to the original value (alpha = 0.62), and test-retest correlation at four months follow-up was moderately encouraging for a short instrument such as this (n = 31, test retest intraclass correlation = 0.58), and change at the mean level was minimal, but marginally significant (from an average of 3.3 to 3.8, p = 0.06). Analyses of nurse ratings of patients' behaviour at the clinic showed that SAPAS was significantly correlated with nurse ratings of externalizing behaviour (r = 0.42, p = 0.001), and Global Assessment of Functioning (r = -0.36, p = 0.006), but unrelated to intoxication (r = 0.02, NS), or withdrawal (r = 0.20, NS).</p> <p>Conclusion</p> <p>There is evidence that the SAPAS is a modestly valid and relatively reliable brief screening measure of personality disorders in patients with ongoing substance abuse undergoing methadone maintenance. It can be used in situations where limited resources are available, and researchers or others wish to get an impression of the degree of personality pathology in a clinical population, as well as for screening purposes.</p

    Experimental Demonstration of the Fitness Consequences of an Introduced Parasite of Darwin's Finches

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    Introduced parasites are a particular threat to small populations of hosts living on islands because extinction can occur before hosts have a chance to evolve effective defenses. An experimental approach in which parasite abundance is manipulated in the field can be the most informative means of assessing a parasite's impact on the host. The parasitic fly Philornis downsi, recently introduced to the Galápagos Islands, feeds on nestling Darwin's finches and other land birds. Several correlational studies, and one experimental study of mixed species over several years, reported that the flies reduce host fitness. Here we report the results of a larger scale experimental study of a single species at a single site over a single breeding season.We manipulated the abundance of flies in the nests of medium ground finches (Geospiza fortis) and quantified the impact of the parasites on nestling growth and fledging success. We used nylon nest liners to reduce the number of parasites in 24 nests, leaving another 24 nests as controls. A significant reduction in mean parasite abundance led to a significant increase in the number of nests that successfully fledged young. Nestlings in parasite-reduced nests also tended to be larger prior to fledging.Our results confirm that P. downsi has significant negative effects on the fitness of medium ground finches, and they may pose a serious threat to other species of Darwin's finches. These data can help in the design of management plans for controlling P. downsi in Darwin's finch breeding populations

    Understanding emotionally relevant situations in primary dental practice. 3. Emerging narratives

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    Background and aims. Dentists experience considerable occupational stress. Stressful clinical situations can provoke high levels of negative emotions, and situations which are associated with positive emotions tend to be overlooked by practitioners. Reflection regarding difficult situations is encouraged to facilitate learning. Cognitive behavioural therapy (CBT) formulations may be applied to situations appraised both positively and negatively. Analysis and interpretation of the dentist's coping behaviour and the consequent outcomes facilitate learning and reflection upon individual interactions with patients. Method. Twenty primary care dental practitioners in the greater Lincoln area participated in a semi-structured interview which explored their stressful and positive clinical experiences. Some of the episodes were analysed to create CBT formulations. Results and discussion. CBT formulations are presented and the learning points highlighted by this structured presentation are discussed. In particular, it is suggested that this structured reconstruction of events, which highlights dentists' emotions, responses and the transactional effects of coping responses, might well facilitate objective reflective learning either individually or as part of peer to peer support. It should facilitate dentists' emotional processing of events and may thus contribute to stress reduction. Conclusion. CBT formulations of positive and negative dental scenarios may be constructed. It is proposed that this is a useful technique to foster reflection and learning in clinical situations and should lead to improved communication skills and shared decision-making, resulting in fewer complaints and thereby reduced stress. It should also improve dentists' emotional processing
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