Anthropometry profiles of elite rugby players: quantifying changes in lean mass

Objective: To demonstrate the utility of a practical measure of lean mass for monitoring changes in the body composition of athletes. Methods: Between 1999 and 2003 body mass and sum of seven skinfolds were recorded for 40 forwards and 32 backs from one Super 12 rugby union franchise. Players were assessed on 13 (7) occasions ( mean (SD)) over 1.9 (1.3) years. Mixed modelling of log transformed variables provided a lean mass index (LMI) of the form mass/skinfolds(x), for monitoring changes in mass controlled for changes in skinfold thickness. Mean effects of phase of season and time in programme were modelled as percentage changes. Effects were standardised for interpretation of magnitudes. Results: The exponent x was 0.13 for forwards and 0.14 for backs ( 90% confidence limits +/- 0.03). The forwards had a small decrease in skinfolds ( 5.3%, 90% confidence limits +/- 2.2%) between preseason and competition phases, and a small increase ( 7.8%, 90% confidence limits +/- 3.1%) during the club season. A small decrease in LMI (similar to 1.5%) occurred after one year in the programme for forwards and backs, whereas increases in skinfolds for forwards became substantial (4.3%, 90% confidence limits +/- 2.2%) after three years. Individual variation in body composition was small within a season (within subject SD: body mass, 1.6%; skinfolds, 6.8%; LMI, 1.1%) and somewhat greater for body mass (2.1%) and LMI (1.7%) between seasons. Conclusions: Despite a lack of substantial mean changes, there was substantial individual variation in lean mass within and between seasons. An index of lean mass based

Sprint patterns in rugby union players during competition

The purpose of this study was to characterize sprint patterns of rugby union players during competition. Velocity profiles (60 m) of 28 rugby players were initially established in testing from standing, walking, jogging, and striding starts. During competition, the individual sprinting patterns of 17 rugby players were determined from video by using the individual velocity profiles. Forwards commenced sprints from a standing start most frequently (41%), whereas backs sprinted from standing (29%), walking (29%),jogging (29%), and occasionally striding (13%) starts. Forwards and backs achieved speeds in excess of 90% maximal velocity (Vmax) on 5 +/- 4 and 9 +/- 4 occasions (similar to 50% of the sprints performed), respectively, during competition. The higher frequency of sprinting for the backs compared with the forwards highlights the importance of speed training for this positional group. The similar relative distribution of velocities achieved during competition for forwards and backs suggests both positional groups should train acceleration and Vmax qualities. The backs should have a higher total volume of sprint training. Sprinting efforts should be performed from a variety of starting speeds to mimic the movement patterns of competition.

Visualising collaboration via email: Finding the key players

Email is an important form of asynchronous communication. Visualizing analyses of email communication patterns during a collaborative activity help us better understand the nature of collaboration, and identify the key players. By analysing the contents of email communication and adding reflective comments on its perceived importance from the participants of a collaboration new information can be gleaned not immediately obvious in its original flat form. This paper outlines a proof-of-concept prototype collaborative email visualisation schema. Data from a collaboration case study is analysed and subsequently employed to construct a display of the relative impact of both key players and the types of email used.

The micro-politics of operational adjustment:veto players and the consolidation of demand in the NHS

Recent reports about procurement within the NHS have been highly critical. One problem identified in the reports is the fragmentation of NHS demand across an unnecessarily large number of suppliers. This fragmentation is said to increase transaction costs, reduce opportunities for scale economies and reduce NHS leverage over suppliers. It has been suggested, therefore, that an important way of improving procurement in the NHS is the better consolidation of demand with a lower number of preferred suppliers. However, such a policy, because it will create ‘winners’ and ‘losers’ within NHS organisations, has political as well as technical and practical ramifications. In this article, the authors present a model, the Veto Players Model, in order to assist managers to address these political ramifications. In the article, the authors not only demonstrate the utility of this model with regard to demand consolidation policies, but also argue that the model provides useful lessons for change management initiatives more generally.

Voluntary, Chronic Dehydration in Adolescent American Football Players

The purpose of the study was to determine whether voluntary acute or chronic dehydration occurs in a male adolescent athletic population during twicea- day American football practice sessions. We conclude that participants will voluntarily rehydrate themselves between practice sessions and will begin to acclimate within three to four days.

Expertise Development in Volleyball: the Role of Early Sport Activities and Players’ Age and Height

The purpose of this study was to analyse the developmental pathway of skilled and less skilled volleyball players by focusing on the quantity and type of sporting activities, as well as their age and height in comparison to peers in those experiences. Retrospective interviews were conducted to provide a longitudinal and detailed account of sport involvement of 30 skilled and 30 less skilled volleyball players (15 male and 15 female players per group) throughout different developmental stages (stage 1: 8-12 years; stage 2: 13-16 years; stage 3: 17-20 years). Results indicated that the developmental pathway of these volleyball players (i.e. skilled and less skilled) was characterized by an early diversified sport involvement with a greater participation in sport activities during stages 1 and 2. However, skilled players specialized later in volleyball (between age 14 and 15) and performed more hours of volleyball at stage 3 (from 17 years of age onwards). Also, skilled players (male and female) were younger in both the diversified sport activities and volleyball at the later stages of development (i.e. stages 2 and 3), and skilled female players were taller than peers in those activities in the early stages of development (i.e. stages 1 and 2). The present findings suggest early diversification as a feasible pathway to reach expertise in volleyball and highlight the importance of practicing with older peers once specialization in the main sport has occurred. The findings highlight the need for coaches and sport programs to consider different stimuli existing within the training environment (i.e. characteristics of athletes, such as age and height) that influence the quality of practice and contribute to players’ expertise development.

Expert players accurately detect an opponent's movement intentions through sound alone

Sounds offer a rich source of information about events taking place in our physical and social environment. However, outside the domains of speech and music, little is known about whether humans can recognize and act upon the intentions of another agent’s actions detected through auditory information alone. In this study we assessed whether intention can be inferred from the sound an action makes, and in turn, whether this information can be used to prospectively guide movement. In two experiments experienced and novice basketball players had to virtually intercept an attacker by listening to audio recordings of that player’s movements. In the first experiment participants had to move a slider, while in the second one their body, to block the perceived passage of the attacker as they would in a real basketball game. Combinations of deceptive and non-deceptive movements were used to see if novice and/or experienced listeners could perceive the attacker’s intentions through sound alone. We showed that basketball players were able to more accurately predict final running direction compared to non-players, particularly in the second experiment when the interceptive action was more basketball specific. We suggest that athletes present better action anticipation by being able to pick up and use the relevant kinematic features of deceptive movement from event-related sounds alone. This result suggests that action intention can be perceived through the sound a movement makes and that the ability to determine another person’s action intention from the information conveyed through sound is honed through practice.

Aerobic and anaerobic test performance among elite male football players in different team positions

The purpose was to determine the magnitude of aerobic and anaerobic performance factors among elite male football players in different team positions. Thirty-nine players from the highest Swedish division classified as defenders (n=18), midfield players (n=12) or attackers (n=9) participated. Their mean (± sd) age, height and body mass (bm) were 24.4 (±4.7) years, 1.80 (±5.9)m and 79 (±7.6)kg, respectively. Running economy (RE) and anaerobic threshold (AT) was determined at 10, 12, 14, and 16km/h followed by tests of maximal oxygen uptake (VO2max). Maximal strength (1RM) and average power output (AP) was performed in squat lifting. Squat jump (SJ), counter-movement jump with free arm swing (CMJa), 45m maximal sprint and the Wingate test was performed. Average VO2max for the whole population (WP) was 57.0mL O2•kg-1min-1 . The average AT occurred at about 84% of VO2max. 1RM per kg bm0.67 was 11.9±1.3kg. Average squat power in the whole population at 40% 1RM was 70±9.5W per kg bm0.67 . SJ and CMJa were 38.6±3.8cm and 48.9±4.4cm, respectively. The average sprint time (45m) was 5.78± 0.16s. The AP in the Wingate test was 10.6±0.9W•kg-1 . The average maximal oxygen uptake among players in the highest Swedish division was lower compared to international elite players but the Swedish players were better off concerning the anaerobic threshold and in the anaerobic tests. No significant differences were revealed between defenders, midfielders or attackers concerning the tested parameters presented above.