217 research outputs found

    The effects of Bodymax high-repetition resistance training on measures of body composition and muscular strength in active adult women

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    This is the author's PDF version of an article published in Journal of strenght and conditioning research in 2003. The definitive version is available at http://www.nsca-jscr.orgThe purpose of this study was to investigate the effects of a light, high-repetition resistance-training program on skinfold thicknesses and muscular strength in women. Thirty-nine active women (mean age 38.64 +/- 4.97 years) were randomly placed into a resistance-training group (RT; n = 20) or a control group (CG; n = 19). The RT group performed a resistance-training program called Bodymax for 1 hour, 3 d.wk(-1), which incorporated the use of variable free weights and high repetitions in a group setting. The CG group continued its customary aerobic training for 1 hour 3 d.wk(-1). Five skinfold and 7 muscular strength measures were determined pretraining and after 12 weeks of training. Sum of skinfolds decreased (-17 mm; p < 0.004) and muscular strength increased (+57.4 kg; p < 0.004) in the RT group. Effect sizes for individual skinfold sites and strength measures were "medium" and "high," respectively. Bodymax is an effective resistance-training program for reducing skinfold thickness and increasing muscular strength in active women. Therefore, women with a similar or lower-activity status should consider incorporating such training into their regular fitness programs

    The reproducibility of perceptually regulated exercise responses during short-term cycle ergometry

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    This is the author's PDF version of an article published in International journal of sports medicine in 2004. The definitive version is available at www.thieme-connect.com.The purpose of this study was to assess the reproducibility over four trials of perceptually regulated exercise intensity during short-term cycle ergometry. Recent research has suggested that an improvement in the reproducibility (better agreement) of the exercise output would be observed with a repeated practice of using regulatory tools such as Borg’s 6-20 rating of perceived exertion (RPE) scale. Eighteen healthy active volunteers (nine males mean age (± SD) 24.7 ± 3.4 yr, and nine females 27.6 ± 5.4 yr) completed four identical intermittent effort production trials on a cycle ergometer, over a period of two-three weeks, with all trials being between three and five days apart. After warm-up, the volunteers were asked to produce four x three-minute bouts of exercise at RPE levels: 13, 15, 9, and 17 (in this order). Power output (W), percentage maximum heart rate reserve (%MHRR), and oxygen consumption (VO2; ml•kg-1•min-1) were recorded in the final minute of each bout. Analysis revealed that the 95% limits of agreement (LoA) between repeated trials did not decrease for the objective markers of exercise intensity, remaining wide throughout. In the worst case comparisons the LoA represented changes (expressed as a proportion of the mean of two trials) of up to 58.3% in power output (T2 vs. T3 at RPE 9), 65.5% in %MHRR (T1 vs. T2 at RPE 13) and 36.5% in VO2 (T3 vs. T4 at RPE 17). These findings question the use of ratings of perceived exertion to regulate exercise effort. That the reproducibility of effort is also not seen to improve with practice raises doubts over the validity of using the RPE scale for providing training intensities for this type of exercise.This article was submitted to the RAE2008 for the University of Chester - Allied Health Professions and Studies

    Test-retest reliability in quantitative physical education research: A commentary

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    This is the author's PDF version of an article published in European Physical Education Review ©1998. The definitive version is available at http://epe.sagepub.com.This paper highlights an important statistical development for exercise and physical education research. Traditionally, the Pearson and intraclass correlation coefficients have been liberally used by researchers to quantify the test-retest reliability of many performance, behavioural, and physiologically-related measurements. The suitability of these forms of analyses has recently been challenged by British exercise scientists, who argue that they do not really address what they are meant to, that is, the level of agreement between repeated measurements or scores. As a consequence, our existing knowledge of the reliability of such measurements is questionable and deserves to be re-established with a more appropriate statistical technique. Accordingly, the 95% Limits of Agreement method is presented and offered as an essential supplement for future measurement and evaluation research

    The technical demands of amateur boxing: Effect of contest outcome, weight and ability

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    This is an Accepted Manuscript of an article published by Taylor & Francis in International Journal of Performance Analysis in Sport on April 2016, available online: http://www.tandfonline.com/doi/abs/10.1080/24748668.2016.11868881As research to-date has typically considered the technical features of amateur boxing performance with respect to contest outcome only, this study examined the offensive and defensive technical demands with respect to the independent and interactive effects of contest outcome, weight class and ability. Appraising eight offensive and four defensive actions and their corresponding outcomes (successful/unsuccessful), the technical demands of competitive boxing from 84 English amateurs (age: 21.3 ± 3.1 y; body mass: 68.1 ± 11.4 kg) across 11 weight categories (48 – 91+ kg) and two standards of competition (regional and national) were notated using computerized software. Data analysis reinforced that amateur boxing produces high technical loads (e.g. ~ 25 punches and ~ 10 defences per minute) and that performance is influenced significantly by the study’s independent variables. In particular, boxing standard (ability) was positively associated with external load (frequency of offensive and defensive actions), and winning was associated with high offensive and low defensive frequencies, whereas weight class had an inconsistent impact on technical performance. It is recommended that appraisals of performance and approaches to training and competition should take heed of our observations and that future research considers the role of other independent variables, including opposition quality and ‘style’, likely to affect boxing performance

    The development of a reliable amateur boxing performance analysis template

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    This is an Accepted Manuscript of an article published by Taylor & Francis in Journal of Sports Sciences on 2/11/2012, available online: http://wwww.tandfonline.com/10.1080/02640414.2012.738922The aim of this study was to devise a valid performance analysis system for the assessment of the movement characteristics associated with competitive amateur boxing and assess its reliability using analysts of varying experience of the sport and performance analysis. Key performance indicators to characterise the demands of an amateur contest (offensive, defensive and feinting) were developed and notated using a computerised notational analysis system. Data were subjected to intra- and inter-observer reliability assessment using median sign tests and calculating the proportion of agreement within predetermined limits of error. For all performance indicators, intra-observer reliability revealed non-significant differences between observations (P > 0.05) and high agreement was established (80-100%) regardless of whether exact or the reference value of ±1 was applied. Inter-observer reliability was less impressive for both analysts (amateur boxer and experienced analyst), with the proportion of agreement ranging from 33-100%. Nonetheless, there was no systematic bias between observations for any indicator (P > 0.05), and the proportion of agreement within the reference range (±1) was 100%. A reliable performance analysis template has been developed for the assessment of amateur boxing performance and is available for use by researchers, coaches and athletes to classify and quantify the movement characteristics of amateur boxing

    The importance of perturbations in elite squash: An analysis of their ability to successfully predict rally outcome

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    This is the authors' post-print of an article published in International Journal of Performance Analysis in Sport, 2014.This study investigated the presence of perturbations within elite squash through the analysis of critical incidents responsible for successful rally outcome

    Validity of a pictorial perceived exertion scale for effort estimation and effort production during stepping exercise in adolescent children

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    This is the author's PDF version of an article published in European Physical Education Review ©2002. The definitive version is available at http://epe.sagepub.com.Recent developments in the study of paediatric effort perception have continued to emphasise the importance of child-specific rating scales. The purpose of this study was to examine the validity of an illustrated 1 – 10 perceived exertion scale; the Pictorial Children’s Effort Rating Table (PCERT). 4 class groups comprising 104 children; 27 boys and 29 girls, aged 12.1±0.3 years and 26 boys, 22 girls, aged 15.3±0.2 years were selected from two schools and participated in the initial development of the PCERT. Subsequently, 48 of these children, 12 boys and 12 girls from each age group were randomly selected to participate in the PCERT validation study. Exercise trials were divided into 2 phases and took place 7 to 10 days apart. During phase 1, children completed 5 x 3-minute incremental stepping exercise bouts interspersed with 2-minute recovery periods. Heart rate (HR) and ratings of exertion were recorded during the final 15 s of each exercise bout. In phase 2 the children were asked to regulate their exercising effort during 4 x 4-minute bouts of stepping so that it matched randomly prescribed PCERT levels (3, 5, 7 and 9). Analysis of data from Phase 1 yielded significant (P<0.01) relationships between perceived and objective (HR) effort measures for girls. In addition, the main effects of exercise intensity on perceived exertion and HR were significant (P<0.01); perceived exertion increased as exercise intensity increased and this was reflected in simultaneous significant rises in HR. During phase 2, HR and estimated power output (POapprox) produced at each of the four prescribed effort levels were significantly different (P<0.01). The children in this study were able to discriminate between 4 different exercise intensities and regulate their exercise intensity according to 4 prescribed levels of perceived exertion. In seeking to contribute towards children’s recommended physical activity levels and helping them understand how to self-regulate their activity, the application of the PCERT within the context of physical education is a desirable direction for future research

    The effects of a cycling warm-up including high-intensity heavy-resistance conditioning contractions on subsequent 4 km time trial performance

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    Prior exercise has been shown to improve subsequent performance via different mechanisms. Sport-specific conditioning contractions can be used to exploit the 'post-activation potentiation' (PAP) phenomenon to enhance performance although this has rarely been investigated in short endurance events. The aim of this study was to compare a cycling warm-up with PAP-inducing conditioning contractions (CW) with a moderate intensity warm-up (MW) on performance and physiological outcomes of 4 km time trial. Ten well-trained male endurance cyclists (V[Combining Dot Above]O2max 65.3 +/- 5.6 ml[middle dot]kg-1[middle dot]min-1) performed two 4 km cycling time trials following a 5-minute recovery after a warm-up at 60% of V[Combining Dot Above]O2max for 6.5-minutes (MW), and a warm-up with conditioning contractions (CW) consisting of 5 minutes at 60% of V[Combining Dot Above]O2max then 3 x 10-seconds at 70% of peak power interspersed with 30-seconds recovery. Blood lactate concentrations were measured before and after time trial. Expired gases were analysed along with time, power output (PO), and peak forces over each 500 m split. Following CW, mean completion time was reduced (1.7 +/- 3.5 s p > 0.05), PO increased (5.1 +/- 10.5 W p > 0.05) as did peak force per pedal stroke (5.7 +/- 11 N p > 0.05) when compared to MW. V[Combining Dot Above]O2 increased (1.4 +/- 1.6 ml[middle dot]kg-1[middle dot]min-1 p < 0.05) following CW, whilst RER decreased (0.05 +/- 0.02 p < 0.05). Physiological and performance differences following CW were greatest over the first 1500 m of the trials. The results suggest a PAP-inducing warm-up alters V[Combining Dot Above]O2 kinetics and can lead to performance improvements in short endurance cycling but work and recovery durations should be optimised for each athlete

    A Possible Cepheid-Like Luminosity Estimator for the Long Gamma-Ray Bursts

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    We present a possible Cepheid-like luminosity estimator for the long gamma-ray bursts based on the variability of their light curves. To construct the luminosity estimator, we use CGRO/BATSE data for 13 bursts, Wind/KONUS data for 5 bursts, Ulysses/GRB data for 1 burst, and NEAR/XGRS data for 1 burst. Spectroscopic redshifts, peak fluxes, and high resolution light curves are available for 11 of these bursts; partial information is available for the remaining 9 bursts. We find that the isotropic-equivalent luminosities L of these bursts positively correlate with a rigorously-constructed measure V of the variability of their light curves. We fit a model to these data that accommodates both intrinsic scatter (statistical variance) and extrinsic scatter (sample variance). If one excludes GRB 980425 from the fit on the grounds that its association with SN 1998bw at a redshift of z = 0.0085 is not secure, the luminosity estimator spans approx. 2.5 orders of magnitude in L, and the slope of the correlation between L and V is positive with a probability of 1 - 1.4 x 10^-4 (3.8 sigma). Although GRB 980425 is excluded from this fit, its L and V values are consistent with the fitted model, which suggests that GRB 980425 may well be associated with SN 1998bw, and that GRB 980425 and the cosmological bursts may share a common physical origin. If one includes GRB 980425 in the fit, the luminosity estimator spans approx. 6.3 orders of magnitude in L, and the slope of the correlation is positive with a probability of 1 - 9.3 x 10^-7 (4.9 sigma). Independently of whether or not GRB 980425 should be included in the fit, its light curve is unique in that it is much less variable than the other approx. 17 light curves in our sample for which the signal-to-noise is reasonably good.Comment: Accepted to The Astrophysical Journal, 31 pages, 13 figures, LaTe

    Effort Perception

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    Research addressing children's perceptions of exercise effort (their ‘perceived exertion’) has appeared steadily in the scientific literature over the last 30 years. Accepting that the established Borg adult rating of perceived exertion (RPE) scale was not appropriate for children, investigators set about developing child-specific scales which employed numbers, words and/or images that were more familiar and understandable. Numerous studies have examined the validity and reliability of such scales as the CERT, PCERT and OMNI amongst children aged 5 to 16, across different modes of exercise (cycling, running, stepping, resistance exercise), protocols (intermittent vs. continuous, incremental vs. non-incremental) and paradigms (estimation vs. production). Such laboratory-based research has enabled the general conclusion that children can, especially with practice, use effort perception scales to differentiate between exercise intensity levels, and to self-regulate their exercise output to match various levels indicated on them. However, inconsistencies in the methodological approaches adopted diminish the certainty of some of the interpretations made by researchers. In addition, though often mentioned, the would-be application of effort perception in physical education and activity/health promotion contexts has been relatively ignored. Accordingly, the scope for research in this applied domain is now considerable
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