1,720,983 research outputs found
An Exploration into the Association Between Maximal Isometric Calf Strength and Sprinting and Jumping Performance in Male Rugby Union Athletes
No full textRugby union is a field invasion sport that requires a variety of high-level physical qualities, in particular, ballistic qualities such as sprinting and jumping. A key physiological mechanism that contributes to ballistic performance in the stretch shortening cycle (SSC), as well as muscular strength. The isometric contraction of the plantar flexors provides tension for the series elastic component to absorb and reproduce energy effectively and contribute to SSC performance. Therefore, the aim of this dissertation was to review current literature exploring the relationship between isometric plantar flexor strength and ballistic performance as well as the underlying mechanisms, followed by an investigation into the relationship in plantar flexor isometric strength and ballistic performance in provincial level rugby union players. Twenty-nine men provincial rugby players (age: 19.3 – 34.1; weight: 82.3 – 124.4 kg) participated in this investigation. Maximal seated and standing isometric plantar flexor strength, countermovement jump (CMJ), pogo jump and 30m sprint were performed. Isometric seated and standing planter flexor metrics (peak force, impulse at 100ms, 150ms and 200ms, and peak vertical force) were analysed using a correlation analysis, along with CMJ (jump height, peak power, flight time/contraction time ratio and concentric peak force), pogo jump (contact time and reactive strength index) and sprint (F0, V0, Pmax, max speed, 10m, 20m and 30m splits) metrics. Standing isometric plantar flexor peak vertical force on the left and right leg were significantly correlated to CMJ jump height (p < 0.03; r = 0.570-0.551), standing isometric plantar flexor peak vertical force on the left leg was significantly correlated with CMJ peak power (p < 0.05; r=0.501), and seated isometric plantar flexor peak vertical force on the left leg had a significant correlation with flight time and contraction time ratio (p ≤ 0.05, r=0.514). The findings of this investigation indicate that maximal isometric plantar flexor strength may provide insight into the overt execution of slow SSC actions, but not for fast SSC movements
Brawn and Brains: An Exploration of Personality in Strength Sports Athletes
No full textStrength sports athletes partake in resistance training behaviours to excel in subtly different strength disciplines. This subgroup of athletes provides an opportunity to discern nuanced differences in personality within a population that consistently adheres to resistance training. Therefore, the aim of this dissertation was to explore the personality dimensions of strength sports athletes to understand whether distinct characteristics are present. Chapter 2 presents a narrative review of the current knowledge about the personality of strength sports athletes from personality and adjacent psychological research. The findings from the review suggested that personality differences are likely expected amongst different strength sports, both dimensionally and at the facet level. However, the review also highlights the dearth of information pertaining to personality research in strength sports athletes, thus indicating further research is warranted. Consequently, chapter 3 explored the personality of five strength sport athlete groups: bodybuilding, powerlifting, weightlifting, strongman/strongwoman athletes, and CrossFit® athletes. It was found that CrossFit® athletes ranked significantly lower on neuroticism (p < 0.01). Additionally, significant facet level differences in artistic interest (p < 0.01), liberalism (p = 0.05), orderliness (p = 0.05), cautiousness (p = 0.04), immoderation (p < 0.01) and vulnerability (p = 0.02) were observed among strength sports athletes. The discussions and conclusion in Chapter 4 contain important limitations and practical recommendations. Specifically, CrossFit® athletes ranked lower on neuroticism and vulnerability, which may indicate that either adopting this style of training has a positive influence on affect and personality or that this sport attracts individuals with lower neuroticism and vulnerability. Furthermore, bodybuilders ranked higher on artistic interest and cautiousness, which may indicate that individuals who are aesthetics-orientated and/or injury-avoidant may prefer this style of training. These findings suggest that a facet-level analysis provides more information about the personality characteristics of different strength sports athletes than the more common dimensional approach. However, additional research exploring the personality of strength athletes over time is needed to further the understanding of this phenomenon
Physical Characteristics of Professional, Semi-Professional and Amateur Male Rugby Union Players
No full textRugby union is a game that requires athletes to have well-developed anaerobic and aerobic capacity. However, it is unclear whether specific physical qualities can be used to distinguish between athletes of higher or lower competition levels. Therefore, the aim of this dissertation was to determine differences in anthropometry, strength, power, speed, and aerobic capacity between male rugby union athletes across professional, semi-professional, and amateur levels of competition. Chapter 2 presents a narrative review of the current physical characteristics of rugby union players across different competition levels and provides practical recommendations to help strengthen methodological approaches within the sport. The review presented findings which proposed a holistic approach to physical development at the lowest level of competition. The review also provided a greater understanding of the different physical characteristics between each level of competition. However, the literature highlights the need for future research to be grown to help continue to distinguish between the ranges of competition and the physical characteristics which could be required to reach the next level of competition. Consequently, chapter 3 compared a variety of physical characteristics between competition levels. Specifically, it was found that the larger differences were between the highest competition level (professionals) and either of the lower competition counterparts (semi-professional and amateur). Professionals produced significantly higher outputs in sections of strength, power, speed, and aerobic capacity markers when compared to the lowest competition amateur athlete. These results suggest that lower-level competition players should look to improve the wide variety of physical characteristics because of the nature of the sport. Furthermore, as players look to move through competition levels, speed characteristics should be monitored and trained closely as they differentiate between all levels of competition. Finally, training application should look to change towards power focused criteria when trying to reach the highest competition level. The information gathered is of value to researchers and strength and conditioning practitioners as it helps to distinguish physical characteristics required to reach a professional level
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
The Acute and Longitudinal Effects of Wearable Resistance: Training to Enhance Change of Direction Performance in Female Netball Athletes
No full textIt is evident that change of direction (COD) ability is important for many field and court sport athletes, and has even been suggested to be one of the key determinants of successful participation in sport. COD is a complex movement and incorporates key qualities associated with athletic performance such as acceleration, deceleration, and directional changes. One common COD manoeuvre is the 180° turn, which is commonly measured via a 5-0-5 COD test. This test traditionally only provides a total time metric, which is of limited value for strength and conditioning practitioners, when it comes to identifying athlete strengths and weaknesses, and creating individualised programs to enhance athletic performance. In terms of training to enhance COD performance, coaches and practitioners have used a range of different specific and non-specific training methods, such as plyometrics, resistance training, sprint training, and COD specific training. In recent years, the use of wearable resistance (WR) has increased in popularity, due to its potential for providing a sport specific overload. This thesis sought to do the following: 1) unpack COD ability and understand the underlying neuromuscular qualities associated with the phases of COD; 2) develop an advanced diagnostic protocol for measuring COD ability, specifically the 180° turn; and, 3) determine the acute and longitudinal effects of a novel training tool (wearable resistance) on 180° COD performance in female athletes.
In Chapters 2 and 3, the lack of data pertaining to the COD ability of female athletes is highlighted, along with a new perspective on understanding COD and how it can be measured via a novel diagnostic protocol. This novel protocol involved the addition of two extra timing gates to the modified 5-0-5 test, therefore providing proxy split times for acceleration, deceleration, 180° turn, and reacceleration out of the turn. In Chapter 4, ten elite level netball athletes volunteered to be a part of the research to determine the reliability of this protocol. It was found that the proposed novel diagnostic protocol was reliable for measuring COD splits and total time in elite level netball athletes (ICCs = 0.57 – 0.97, CVs = 1.1 – 6.6%). Additionally, the strength of association between the splits and total time was investigated to ensure that splits were measuring independent qualities. The greatest shared variance between sub-phases was 68.9% between deceleration and reacceleration 2 and was the only variable to explain more than 50% of shared variance between sub-phases, suggesting the splits are measuring relatively independent qualities. Further enhancing the diagnostics of this protocol, by including in-sole inertial measurement unit (IMU) technology, was the aim of Chapter 5. The IMU technology was found reliable for providing maximum speed, peak deceleration, and peak acceleration during a modified 5-0-5 COD test (ICCs = 0.57 – 0.96, CVs = 1.8 – 9.5%). Given the acceptable reliability of this advanced diagnostic protocol for a modified 5-0-5 test, it was of interest to determine its utility for coaches with athlete profiling. Chapter 6 focused on determining the insights this novel diagnostic protocol could provide coaches. Of particular interest was to understand what proportion of the test was actually spent in changing direction, if anthropometry and positional differences influenced sub-phase performance and whether a sub-phase analysis could provide better diagnostic information to guide individualisation of programming. It was found that the highest percentage of time was spent during the 180° turn and reacceleration phase (~23%). It appeared that heavier athletes were significantly slower during the modified 5-0-5 test (8.68%), however no differences were identified between taller and shorter players. The use of a sub-phase rank order table provided deeper insights into an individual’s COD sub-phase ability, allowing coaches to easily identify individual athletes’ strengths and weaknesses in a team sport environment.
A repeated measures design was used in Chapter 7, to determine the acute effects of upper and lower body WR on sub-phase and total time 5-0-5 COD performance. Total time was significantly slower for both WR conditions compared to no load (p < 0.05, ES = 0.22 – 0.25). The greatest overload was found for the initial acceleration split (split 1) for both loading conditions (p < 0.05, ES = 0.67 – 0.79). Both loading conditions had moderate to large significant effects on peak deceleration (ES = 0.56 – 0.82) and maximum speed (ES = -0.50 - -0.60). It appeared that both upper and lower body WR significantly overloaded an athlete during a modified 5-0-5 test, and therefore may provide a potential training stimulus to elicit positive COD performance adaptations if used over an extended period of time.
Chapter 8 used a matched-paired randomised control design to determine the effectiveness of warming up with lower-limb WR on COD, sprinting and jumping in female netball athletes. Thirty female high-school premier netball athletes were matched for COD speed and randomly allocated to either WR training (WRT) or an unloaded group (CON). Both groups performed the same 15-minute warm-up two times per week, for six weeks. The WR group was wearing shank loaded WR, which progressed throughout the 6-week intervention. Pre- and post-training data were collected for 5- and 15-m linear sprint times, modified 5-0-5 COD splits and total time, and single leg broad, lateral and vertical countermovement jumps. The main findings of this Chapter were; 1) both groups significantly decreased their 5 m linear sprint times (WRT = -4.41%, ES = -1.60; CON = -2.60%, ES = -0.71), while only the WRT significantly decreased their 15 m time (-2.14%, ES = -1.55); 2) there were no significant decreases in 5-0-5 total time for either group, however the WRT group significantly decreased their acceleration (-7.40%, ES = -0.60) and COD split (-9.73%, ES = -1.02); and, 3) both groups increased their lateral jump (WRT: 4.60 – 6.62%, ES = 0.67 – 0.96; CON: 5.48 – 6.06%, ES = 0.73 - 0.75), while only the WRT group increased (p < 0.05) their broad jump (3.57 – 4.18%, ES = 0.57 – 0.67).
Chapter 9 provided a summary of all the key findings from each Chapter and their practical applications for coaches and practitioners. The limitations of this thesis were also explored, followed by future research directions in the use of WR as a tool for developing athleticism
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
- …
