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

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

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

Spall Characteristics of Additively Manufactured Stainless Steel

Additive manufacturing (AM) has rapidly transformed from a novelty prototyping technology into a growing sector of production across a wide range of industries. Much work has been documented in literature to demonstrate the behavior of AM products under static and quasi-static loading conditions. However, the behavior of AM materials under high strain rate loading is not as well understood. This research attempts to advance the fundamental knowledge of the relationship between the unique aspects of AM and the mechanical performance under high velocity impact loading conditions. This project examines the behavior of AM 316L stainless steel (SS) exposed to high velocity impact, the associated shock wave propagation, and the resistance to fracture as a function of orientation and internal engineered features (a design tool unique to AM). This research involves fabrication, characterization, plate impact spallation testing, experiment modeling, and post-mortem analysis of 316L SS samples fabricated using laser powder bed fusion (LPBF). Connections and correlations were established using a variety of data sets. A build-impact orientation study and two engineered porosity studies (one with random distribution across the bulk and the other with single voids strategically placed) were conducted to develop a better understanding of shock wave propagation and spall fracture related to the unique aspects and capabilities of LPBF fabrication. This research demonstrated that impact orientation with respect to build direction influences the extent and location of spall damage due to the relative microstructural anisotropy and collections of powder filled voids slow and weaken the progressing shock front by presenting disturbances in portions of the wave front. An engineering design study based on the findings of the earlier studies further utilized purposeful engineering design to control the propagation of the shock wave (and associated pressure front) through the material. The use of internal features, a capability unique to LPBF, was the primary goal of the study. This study successfully demonstrated that a large, powder-filled void space placed within a solid sample provides damping qualities that both slow the progression of the shock front and reduce the magnitude of the pressure stress realized at the rear free surface (opposite of impact). Overall, the results of this research demonstrate that the anisotropic properties and unique capabilities of LPBF can be leveraged to control shock wave propagation and resultant damage in stainless steel materials. Unique aspects of this research include (1) comparing the spall response of LPBF fabricated samples to shock loading conditions applied at varying orientation relative to the build direction, (2) examining the use of powder-filled engineered void spaces to reduce the magnitude and velocity of the progressing shock front, along with the resulting damage, and (3) in both cases coupling the results of plate impact experiments with as-built and post-mortem sample characterization

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

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

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

Growth and form of the mound in Gale Crater, Mars: Slope wind enhanced erosion and transport

Ancient sediments provide archives of climate and habitability on Mars. Gale Crater, the landing site for the Mars Science Laboratory (MSL), hosts a 5-km-high sedimentary mound (Mount Sharp/Aeolis Mons). Hypotheses for mound formation include evaporitic, lacustrine, fluviodeltaic, and aeolian processes, but the origin and original extent of Gale’s mound is unknown. Here we show new measurements of sedimentary strata within the mound that indicate ∼3° outward dips oriented radially away from the mound center, inconsistent with the first three hypotheses. Moreover, although mounds are widely considered to be erosional remnants of a once crater-filling unit, we find that the Gale mound’s current form is close to its maximal extent. Instead we propose that the mound’s structure, stratigraphy, and current shape can be explained by growth in place near the center of the crater mediated by wind-topography feedbacks. Our model shows how sediment can initially accrete near the crater center far from crater-wall katabatic winds, until the increasing relief of the resulting mound generates mound-flank slope winds strong enough to erode the mound. The slope wind enhanced erosion and transport (SWEET) hypothesis indicates mound formation dominantly by aeolian deposition with limited organic carbon preservation potential, and a relatively limited role for lacustrine and fluvial activity. Morphodynamic feedbacks between wind and topography are widely applicable to a range of sedimentary and ice mounds across the Martian surface, and possibly other planets

The development of a reliable amateur boxing performance analysis template

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

Longboard classification using Machine Learning

There are several techniques a rider can choose from that they can perform being distributed along the long-board ride. This research aims to create a machine-learning model that can efficiently classify these techniques at different periods of time using raw acceleration data. This paper presents the complete workflow of the application. This application involves analytical geometry, multidimensional calculus, and linear algebra and can be used to visualize and normalize time-invariant object paths. This model focuses on displacement data calculated from raw acceleration data and gyro sensor data from a smartphone application called Physics Toolbox Sensor Suite . We extracted features from each dynamic window of time in the displacement data and then fed them into machine learning algorithms with various statistical features, including supervised learning classifiers and Long short-term memory. We found that the Decision Tree with post-pruning produces a performance 93.4%, and the Random Forest produces a performance 96.8%. Although Decision Tree works faster than Random Forest, we ultimately used Random Forest classifier in our application, since the application does not perform prediction and classification in real-time

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

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