Optimising classification of proximal arm strength impairment in wheelchair rugby: A proof of concept study.

This study examined the relationship between proximal arm strength and mobility performance in wheelchair rugby (WR) athletes and examined whether a valid structure for classifying proximal arm strength impairment could be determined. Fifty-seven trained WR athletes with strength impaired arms and no trunk function performed six upper body isometric strength tests and three 10 m sprints in their rugby wheelchair. All strength measures correlated with 2 m and 10 m sprint times (r ≥ -0.43; p ≤ 0.0005) and were entered into k-means cluster analyses with 4-clusters (to mirror the current International Wheelchair Rugby Federation [IWRF] system) and 3-clusters. The 3-cluster structure provided a more valid structure than both the 4-cluster and existing IWRF system, as evidenced by clearer differences in strength (Effect sizes [ES] ≥ 1.0) and performance (ES ≥ 1.1) between adjacent clusters and stronger mean silhouette coefficient (0.64). Subsequently, the 3-cluster structure for classifying proximal arm strength impairment would result in less overlap between athletes from adjacent classes and reduce the likelihood of athletes being disadvantaged due to their impairment. This study demonstrated that the current battery of isometric strength tests and cluster analyses could facilitate the evidence-based development of classifying proximal arm strength impairment in WR.

Validation of new measures of arm coordination impairment in Wheelchair Rugby.

This study aims were twofold: (1) to evaluate the construct validity of the Repetitive Movement Test (RMT) a novel test developed for Wheelchair Rugby classification which evaluates arm coordination impairment at five joints - shoulder, elbow, forearm, wrist and fingers - and (2), pending sufficiently positive results, propose objective minimum impairment criteria (MIC). Forty-two WR athletes with an eligible coordination impairment, and 20 volunteers without impairment completed the RMT and two clinically established coordination tests: the finger-nose test (FNT) and the spiral test (ST). Coordination deduction (CD), an ordinal observational coordination scale, currently used in WR classification, was obtained. Spearman-rank correlation coefficients (SCC) between RMT and ST (0.40 to 0.67) and between RMT and CD (0.31 to 0.53) generally supported RMT construct validity, SCC between RMT and FNT were lower (0.12-0.31). When the scores on ST, FNT and RMT from the sample of WR players were compared with the scores from volunteers without impairment, 93.5% to 100% of WR players had scores > 2SD below the mean of volunteers without impairment on the same test. In conclusion, RMT at the elbow, forearm, wrist and fingers have sufficient construct validity for use in WR. MIC were recommended with ST and RMT.

Rugby union referees' physical and physiological demands across different competitive levels.

BACKGROUND: The purpose of this study was to compare the match demands of officiating 15-a-side rugby union at different competitive levels. METHODS: Data was collected using Global Navigation Satellite Systems from 21 referees during 82 competitive rugby union matches across three different competitive levels: 1) professional; 2) semi-professional; 3) amateur. RESULTS: Compared with referees at the professional and semi-professional levels, referees at the amateur level covered less total distance (P=0.005). Additionally, these referees covered less distance jogging, and at low and medium intensity (all P<0.05), and had less time between repeated high-intensity efforts (P<0.001). Furthermore, compared with referees at the semi-professional and amateur levels, referees at the professional level had a higher sprint duration and covered more distance sprinting (all P<0.05), and achieved a higher maximal speed during the longest repeated high-intensity effort or "worst-case scenario" (P=0.026). The professional level referees also displayed a lower average heart rate (P<0.001), spent a higher percentage of time at <60% HRmax (P<0.001), and a lower percentage of time between 71% and 80% HRmax (P=0.004). Finally, external and internal load were strongly correlated for referees at the semi-professional level only (r=0.75, P<0.001). CONCLUSIONS: Overall, the findings demonstrate that refereeing 15-a-side rugby union is more physically demanding at higher competitive levels, particularly in terms of high-intensity efforts. The results provide important information for practitioners involved in the physical preparation and training of rugby union referees.

Examining the evolution and classification of player position using performance indicators in the National Rugby League during the 2015-2019 seasons.

OBJECTIVES: This study aimed to: 1) examine recent seasonal changes in performance indicators for different National Rugby League (NRL) playing positions; and 2) determine the accuracy of performance indicators to classify and discriminate positional groups in the NRL. DESIGN: Retrospective, longitudinal analysis of individual performance metrics. METHODS: 48 performance indicators (e.g. passes, tackles) from all NRL games during the 2015-2019 seasons were collated for each player´s match-related performance. The following analyses were conducted with all data: (i) one-way ANOVA to identify seasonal changes in performance indicators; (ii) principal component analysis (PCA) to group performance indicators into factors; (iii) two-step cluster analysis to classify playing positions using the identified factors; and (iv) discriminant analysis to discriminate the identified playing positions. RESULTS: ANOVA showed significant differences in performance indicators across seasons (F=2.3-687.7; p=0-0.05; partial η2=0.00-0.075). PCA pooled all performance indicators and identified 14 factors that were included in the two-step cluster analysis (average silhouette=0.5) that identified six positional groups: forwards, 26.7%, adjustables, 17.2%, interchange, 23.2%, backs, 20.9%, interchange forwards, 5.5% and utility backs, 6.5%. Lastly, discriminant analysis revealed five discriminant functions that differentiated playing positions. CONCLUSIONS: Results indicated that player's performance demands across different playing positions did significantly change over recent seasons (2015-2019). Cluster analysis yielded a high-level of accuracy relative to playing position, identifying six clusters that best discriminated positional groups. Unsupervised analytical approaches may provide sports scientists and coaches with meaningful tools to evaluate player performance and future positional suitability in RL.

Match and Training Injuries in Women's Rugby Union: A Systematic Review of Published Studies.

BACKGROUND: There is a paucity of studies reporting on women's injuries in rugby union. OBJECTIVE: The aim of this systematic review was to describe the injury epidemiology for women's rugby-15s and rugby-7s match and training environments. METHODS: Systematic searches of PubMed, SPORTDiscus, Web of Science Core Collection, Scopus, CINAHL(EBSCO) and ScienceDirect databases using keywords. RESULTS: Ten articles addressing the incidence of injury in women's rugby union players were retrieved and included. The pooled incidence of injuries in women's rugby-15s was 19.6 (95% CI 17.7-21.7) per 1000 match-hours (h). Injuries in women's rugby-15s varied from 3.6 (95% CI 2.5-5.3) per 1000 playing-h (including training and games) to 37.5 (95% CI 26.5-48.5) per 1000 match-h. Women's rugby-7s had a pooled injury incidence of 62.5 (95% CI 54.7-70.4) per 1000 player-h and the injury incidence varied from 46.3 (95% CI 38.7-55.4) per 1000 match-h to 95.4 (95% CI 79.9-113.9) per 1000 match-h. The tackle was the most commonly reported injury cause with the ball carrier recording more injuries at the collegiate [5.5 (95% CI 4.5-6.8) vs. 3.5 (95% CI 2.7-4.6) per 1000 player-game-h; χ2(1) = 6.7; p = 0.0095], and Women's Rugby World Cup (WRWC) [2006: 14.5 (95% CI 8.9-23.7) vs. 10.9 (95% CI 6.2-19.2) per 1000 match-h; χ2(1) = 0.6; p = 0.4497; 2010: 11.8 (95% CI 6.9-20.4) vs. 1.8 (95% CI 0.5-7.3) per 1000 match-h; χ2(1) = 8.1; p = 0.0045] levels of participation. Concussions and sprains/strains were the most commonly reported injuries at the collegiate level of participation. DISCUSSION: Women's rugby-7s had a higher un-pooled injury incidence than women's rugby-15s players based on rugby-specific surveys and hospitalisation data. The incidence of injury in women's rugby-15s and rugby-7s was lower than men's professional rugby-15s and rugby-7s competitions but similar to male youth rugby-15s players. Differences in reporting methodologies limited comparison of results. CONCLUSION: Women's rugby-7s resulted in a higher injury incidence than women's rugby-15s. The head/face was the most commonly reported injury site. The tackle was the most common cause of injury in both rugby-7s and rugby-15s at all levels. Future studies are warranted on injuries in women's rugby-15s and rugby-7s. PROSPERO REGISTRATION NUMBER: CRD42018109054 (last updated on 17 January 2019).

Association between community socioeconomic characteristics and access to youth flag football.

BACKGROUND: The American Academy of Pediatrics has recommended that opportunities for non-tackling American football (e.g., flag football) be expanded, given concerns about the risks of brain trauma from tackle football. This study tested the hypothesis that flag football would be more accessible in communities characterised by higher socioeconomic status residents. METHODS: In July 2017, the locations of community-based organisations offering youth flag and tackle football for youth between the ages of 6 and 13 in two US states (Georgia and Washington) were aggregated (n=440). Organisations were coded in terms of the availability of tackle and/or flag football teams for youth at each year of age between 6 and 13. Multivariate logistic regression analyses were used to assess the odds of a community-based football organisation offering flag football, by community socioeconomic and demographic characteristics. RESULTS: In both states, communities with more educated residents were more likely to offer flag football for youth aged 6-12. For example, among 6 year-olds every 10% increase in the number of adult residents with a college education was associated with 1.51 times the odds of flag football availability (95% CI 1.22 to 1.86, P<0.001). CONCLUSION: These results suggest that youth living in communities characterised by low educational attainment are less likely than other youth to have the option of a lower contact alternative to tackle football. Relying on voluntary community-level adoption of lower contact alternatives to tackle football may result in inequitable access to such sport options. This may contribute to an inequitable burden of brain trauma from youth sport.

Altering the Speed Profiles of Wheelchair Rugby Players With Game-Simulation Drill Design.

PURPOSE: To examine the speed profiles of elite wheelchair rugby (WCR) players during game-simulation training drills of differing player number and shot-clock regulations. A secondary aim was to determine whether the profiles were further influenced by player classification. METHODS: Eight elite WCR players (low-point n = 3, high-point n = 5) were monitored using a radio-frequency-based indoor tracking system during training sessions over a 5-mo period. Speed profiles were collected for 3 modified game-simulation drills-3-versus-3 drills (n = 8 observations), 30-s shot clock (n = 24 observations), and 15-s shot clock (n = 16 observations)-and were compared with regular game-simulation drills (4 vs 4, 40-s shot clock; n = 16 observations). Measures included mean and peak speed; exercise-intensity ratios, defined as the ratio of time spent performing at high and low speeds; and the number of high-speed activities performed. RESULTS: Compared with regular game-simulation drills, 3-versus-3 drills elicited a moderate increase in mean speed (6.3%; effect size [ES] = 0.7) and the number of high-speed activities performed (44.1%; ES = 1.1). Minimal changes in speed profiles were observed during the 30-s shot clock, although moderate to large increases in all measures were observed during the 15-s shot-clock drills. Classification-specific differences were further identified, with increased activity observed for high-point players during the 3-versus-3 drill and for low-point players during the 15-s shot clock. CONCLUSION: By reducing the number of players on court and the shot clock to 15 s, coaches can significantly increase elite WCR players' speed profiles during game-simulation drills.

Cardiovascular disease risk profile of NCAA Division III intercollegiate football athletes: a pilot study.

OBJECTIVES: Concerns about the long-term cardiovascular health implications of American football participation have been investigated at the professional and Division I levels, but limited research is available at the less resourced Division III level. Therefore, the objective was to assess the cardiovascular disease risk profile of NCAA Division III intercollegiate football athletes. METHODS: Eighty-nine varsity football athletes (age = 19.6 ± 1.7 years, height = 1.81 ± 0.07m, weight = 92.7 ± 16.2kg; n = 21 linemen, n = 68 non-linemen) at a private Division III university volunteered to participate. During a preseason pre-participation physical examination, all participants completed a health history screening form (to assess personal and family history of cardiac related pathologies), and were assessed for height, weight, body mass index (BMI), and blood pressure (BP). Linemen only additionally gave a blood sample for fasting blood glucose and cholesterol analysis, and were assessed for waist and hip circumference, metabolic syndrome, and percent body fat (%BF). These measures were reported as averages and frequencies of elevated cardiovascular. Independent t-tests compared linemen to non-linemen, all other data was presented descriptively. RESULTS: On average, linemen were significantly taller, heavier, had a higher BMI and higher systolic BP than non-linemen (all P < 0.05); there was no difference in diastolic BP between the groups (P = 0.331). The average anthropometric and cardiac risk characteristics for linemen were largely within normal ranges, however analyzed individually, a substantial number of participants were at elevated risk (BMI ≥30 = 85.7%, %BF ≥25 = 71.4%, waist circumference ≥1 = 42.9%, hypertension = 9.5%, high density lipoproteins <40mg/dL = 42.9%, and triglycerides ≥150mg/dL = 6.7%; metabolic syndrome prevalence = 19%). CONCLUSIONS: Similar to research in elite athletics, linemen at a single Division III university have elevated cardiovascular disease risk. Physicians and other healthcare providers should consider this elevated risk during pre-participation physical examinations and in planning educational or dietary programming targeted to promoting cardiovascular health.

Quantification of Competitive Game Demands of NCAA Division I College Football Players Using Global Positioning Systems.

The aim of the present study was to examine the competitive physiological movement demands of National Collegiate Athletic Association (NCAA) Division I college football players using portable global positioning system (GPS) technology during games and to examine positional groups within offensive and defensive teams, to determine if a player's physiological requirements during games are influenced by playing position. Thirty-three NCAA Division I Football Bowl Subdivision football players were monitored using GPS receivers with integrated accelerometers (GPSports) during 12 regular season games throughout the 2014 season. Individual data sets (n = 295) from players were divided into offensive and defensive teams and subsequent position groups. Movement profile characteristics, including total, low-intensity, moderate-intensity, high-intensity, and sprint running distances (m), sprint counts, and acceleration and deceleration efforts, were assessed during games. A one-way ANOVA and post-hoc Bonferroni statistical analysis were used to determine differences in movement profiles between each position group within offensive and defensive teams. For both offensive and defensive teams, significant (p ≤ 0.05) differences exist between positional groups for game physical performance requirements. The results of the present study identified that wide receivers and defensive backs completed significantly (p ≤ 0.05) greater total distance, high-intensity running, sprint distance, and high-intensity acceleration and deceleration efforts than their respective offensive and defensive positional groups. Data from the present study provide novel quantification of position-specific physical demands of college football games and support the use of position-specific training in the preparation of NCAA Division I college football players for competition.

Do physical qualities influence the attainment of professional status within elite 16-19 year old rugby league players?

OBJECTIVES: The current study retrospectively compared the physical qualities of elite academy rugby league players (aged 16-19 years) by career attainment level (i.e., academy or professional). DESIGN: Retrospective cross-sectional and longitudinal design. METHODS: Eighty-one academy rugby league players were assessed for physical qualities (height, body mass, skinfolds, speed, momentum, vertical jump, Yo-Yo Level 1 and 1-RM squat, bench press and prone row) at the Under 17-19 age categories between 2007 and 2012. Player's career attainment level was determined in 2014. Longitudinal changes in physical qualities between Under 17 and 19s were compared by career attainment level. RESULTS: Professional players demonstrated moderate significant advantages for height (d=0.98) and 1-RM squat (d=0.66) at the Under 17s, 1-RM bench press (d=0.76) at the Under 18s and 1-RM prone row (d=0.73) at the Under 19s age categories when compared to academy players. When assessed longitudinally (Under 17s-19s), professional players significantly outperformed academy players for 1-RM squat (η(2)=0.20). Professional players also demonstrated greater increases in body mass (8.2 vs. 2.9kg) and 10m momentum (47 vs. 17kgs(-1)) than academy players between the Under 17s and 19s. CONCLUSIONS: Advanced physical qualities, particularly height and absolute strength, within 16-19 year old players may contribute to attaining professional status in rugby league. Further, the development of body mass and momentum for players within an academy is an important consideration in the progress towards professional rugby league. Therefore, practitioners should aim to identify and develop the physical qualities, especially size and strength, within academy rugby league players.

Muscular Strength and Power Correlates of Tackling Ability in Semiprofessional Rugby League Players.

This study investigated the relationship between muscular strength and power and tackling ability in semiprofessional rugby league players. Thirty-six semiprofessional (mean ± SD age, 23.1 ± 3.6 years) rugby league players, from 3 distinct playing divisions (first grade, second grade, and under 20s), underwent tests of upper-body strength (3 repetition maximum [RM] bench press), lower-body strength (3RM squat), upper-body power (plyometric push-up [PPU]), and lower-body power (countermovement jump). Muscular strength relative to body mass was also calculated. Tackling ability of the players was tested using video analysis of a standardized one-on-one tackling drill. For all players, the strongest correlates of tackling ability were squat (r = 0.67), bench press (r = 0.58), relative squat (r = 0.41), and PPU (r = 0.56). The strongest correlates of tackling ability in first grade players were squat (r = 0.72), bench press (r = 0.72), relative squat (r = 0.86), and PPU (r = 0.70). For second grade players, only relative squat (r = 0.60) and PPU (r = 0.67) were associated with tackling ability. The strongest correlates of tackling ability in under 20s players were squat (r = 0.77), bench press (r = 0.70), and PPU (r = 0.65). The findings of this study demonstrate that muscular strength and upper-body power contribute to tackling ability in semiprofessional rugby league players. Therefore, as long as the technical aspects of tackling technique are adequately coached and practiced, then enhancements in muscular strength and power may serve as foundational components to underpin improvement in tackling ability.

Activity profiles of elite wheelchair rugby players during competition.

PURPOSE: To quantify the activity profiles of elite wheelchair rugby (WCR) players and establish classification-specific arbitrary speed zones. In addition, indicators of fatigue during full matches were explored. METHODS: Seventy-five elite WCR players from 11 national teams were monitored using a radio-frequency-based, indoor tracking system across 2 international tournaments. Players who participated in complete quarters (n = 75) and full matches (n = 25) were included and grouped by their International Wheelchair Rugby Federation functional classification: groups I (0.5), II (1.0-1.5), III (2.0-2.5), and IV (3.0-3.5). RESULTS: During a typical quarter, significant increases in total distance (m), relative distance (m/min), and mean speed (m/s) were associated with an increase in classification group (P < .001), with the exception of groups III and IV. However, group IV players achieved significantly higher peak speeds (3.82 ± 0.31 m/s) than groups I (2.99 ± 0.28 m/s), II (3.44 ± 0.26 m/s), and III (3.67 ± 0.32 m/s). Groups I and II differed significantly in match intensity during very-low/low-speed zones and the number of high-intensity activities in comparison with groups III and IV (P < .001). Full-match analysis revealed that activity profiles did not differ significantly between quarters. CONCLUSIONS: Notable differences in the volume of activity were displayed across the functional classification groups. However, the specific on-court requirements of defensive (I and II) and offensive (III and IV) match roles appeared to influence the intensity of match activities, and consequently training prescription should be structured accordingly.

Physical qualities and activity profiles of sub-elite and recreational Australian football players.

OBJECTIVES: To investigate the relationship between physical qualities and match activity profiles of recreational Australian football players. DESIGN: Prospective cohort study. METHODS: Forty players from three recreational Australian football teams (Division One, Two and Three) underwent a battery of fitness tests (vertical jump, 10 and 40 m sprint, 6 m × 30 m repeated sprint test, Yo-Yo intermittent recovery level Two and 2-km time trial). The activity profiles of competitive match-play were quantified using 10-Hz Global Positioning System units. RESULTS: Division One players possessed greater maximum velocity, Yo-Yo level Two and 2-km time trial performances than Division Two and Three players. In addition, Division One players covered greater relative distance, and relative distances at moderate- and high-intensities during match-play than Division Two and Three players. Division Two players had better 2-km time trial performances than Division Three players. Positive associations (P < 0.05) were found between 10 m acceleration, maximum velocity, Yo-Yo level Two and 2-km time trial performances and relative distance, and relative distances covered at moderate- and high-intensities during match-play. Moderate relationships were found between vertical jump and relative distance and high-intensity running. CONCLUSIONS: Sub-elite Australian football players competing at a higher level exhibit greater physical qualities and match-play activity profiles than lesser-skilled recreational players. Acceleration and maximum velocity, 2-km time trial and Yo-Yo level Two performances discriminate between players of different playing levels, and are related to physical match performance in recreational Australian football. The development of these qualities is likely to contribute to improved match performance in recreational Australian football players.

Match-to-match variation in physical activity and technical skill measures in professional Australian Football.

OBJECTIVES: To determine the match-to-match variability in physical activity and technical performance measures in Australian Football, and examine the influence of playing position, time of season, and different seasons on these measures of variability. DESIGN: Longitudinal observational study. METHODS: Global positioning system, accelerometer and technical performance measures (total kicks, handballs, possessions and Champion Data rank) were collected from 33 players competing in the Australian Football League over 31 matches during 2011-2012 (N=511 observations). The global positioning system data were categorised into total distance, mean speed (mmin(-1)), high-speed running (>14.4 kmh(-1)), very high-speed running (>19.9 kmh(-1)), and sprint (>23.0 kmh(-1)) distance while player load was collected from the accelerometer. The data were log transformed to provide coefficient of variation and the between subject standard deviation (expressed as percentages). RESULTS: Match-to-match variability was increased for higher speed activities (high-speed running, very high-speed running, sprint distance, coefficient of variation %: 13.3-28.6%) compared to global measures (speed, total distance, player load, coefficient of variation %: 5.3-9.2%). The between-match variability was relativity stable for all measures between and within AFL seasons, with only few differences between positions. Higher speed activities (high-speed running, very high-speed running, sprint distance), but excluding mean speed, total distance and player load, were all higher in the final third phase of the season compared to the start of the season. CONCLUSIONS: While global measures of physical performance are relatively stable, higher-speed activities and technical measures exhibit a large degree of between-match variability in Australian Football. However, these measures remain relatively stable between positions, and within and between Australian Football League seasons.

Understanding mismatches in body size, speed and power among adolescent rugby union players.

OBJECTIVES: With adolescent sport increasingly challenged by mismatches in size, new strategies are important to maximize participation. The objectives were to (1) improve the understanding of mismatches in physical size, speed and power in adolescent rugby union players, (2) explore associations between size and performance with demographic, playing-history, and injury profiles, and (3) explore the applicability of existing criteria for age/body mass-based dispensation (playing-down) strategies. DESIGN: Cross-sectional study. METHODS: Four hundred and eighty-five male community rugby union players were recruited from three Australian states selected to represent community-based U12, U13, U14 and U15 players. Body mass, stature, speed (10, 30, and 40 m sprints) and lower-leg power (relative peak power and relative peak force) were measured. Independent student t-tests, linear regressions and Chi square analyses were undertaken. RESULTS: Mean values in age groups for size, speed and power masked considerable overlap in the ranges within specific age groups of adolescent rugby players. Only a small proportion of players (approximately 5%) shared the highest and lowest tertiles for speed, relative peak power and body mass. Physical size was not related to injury. The mean body mass of current community rugby union players was above the 75th percentile on normative growth-charts. CONCLUSION: The notion that bigger, faster, and more powerful characteristics occur simultaneously in adolescent rugby players was not supported in the present study. Current practices in body mass-based criteria for playing down an age group lack a sufficient evidence for decision-making. Dispensation solely based on body mass may not address mismatch in junior rugby union.

Muscle characteristics and body composition of NCAA division I football players.

The purpose of this study was to examine muscle characteristics of the vastus lateralis (VL) and body composition of National Collegiate Athletic Association (NCAA) Division I football players. Sixty-nine Division I football players (mean ± SD; age: 20.0 ± 1.1 years; height: 186.2 ± 7.0 cm; body mass: 106.3 ± 21.1 kg; %fat: 17.8 ± 4.6%) were stratified by player position, race, year, and starter status. A panoramic scan of the VL was performed using a GE Logiq-e B-mode ultrasound. Muscle cross-sectional area (mCSA) and echo intensity (EI) were determined using Image-J software from the VL scan. Body composition measures were determined using dual-energy x-ray absorptiometry (DXA). For mCSA, defensive linemen (DL: 46.7 ± 4.2 cm) had significantly greater CSA (p ≤ 0.05) than wide receivers (WR), linebackers (LB), defensive backs (DB), punters/kickers (PK), and running backs (RB). There were no significant differences for EI (p > 0.05) between positions. Offensive linemen and DL had significantly greater %fat than WR, LB, DB, PK, and RB (p ≤ 0.05); greater lean mass than all other positions (p ≤ 0.05); and more fat mass than quarterbacks, WR, LB, DB, PK, and RB (p ≤ 0.05). There were no muscle or body composition differences for race, year, or starter status. Because no differences between positions were observed for EI measures, it may indicate that competitive athletes have increased muscle quality regardless of body composition differences. Ultrasound and DXA measures may be useful to identify muscle characteristics and imbalances if a player gains or loses weight, suffers an injury, or declines in performance.

Abdominal body composition differences in NFL football players.

The purpose of this study was to examine visceral fat mass as well as other measures abdominal body composition in National Football League (NFL) players before the start of the season. Three hundred and seventy NFL football players were measured before the start of the season using dual-energy x-ray absorptiometry. Regional fat and lean mass was measured for each player. Players were categorized into 3 groups based on positions that mirror each other: linemen; linebackers/tight ends/running backs and wide receivers/defensive backs. Significant differences were observed between the position groups for both lean and fat regional measurements. However, the magnitude of difference was much greater for fat measures than lean measures. Additionally, a threshold was observed (∼114 kg) at which there is a greater increase in fat accumulation than lean mass accumulation. The increase in fat accumulation is distributed to the abdominal region where thresholds were observed for subcutaneous abdominal fat accumulation (12.1% body fat) and visceral abdominal fat accumulation (20.1% body fat), which likely explains the regional fat differences between groups. The results of this study suggest that as players get larger, there is more total fat than total lean mass accumulation and more fat is distributed to the abdominal region. This is of importance as increased fat mass may be detrimental to performance at certain positions. The thresholds observed for increased abdominal fat accumulation should be monitored closely given recent research observed that abdominal obesity predicts lower extremity injury risk and visceral adipose tissue's established association with cardiometabolic risk.

Improvement of the classification system for wheelchair rugby: athlete priorities.

A representative sample (N=302) of the wheelchair rugby population responded to a survey about the classification system based on prioritized items by International Wheelchair Rugby Federation members. Respondents stated, "The classification system is accurate but needs adjustments" (56%), "Any athlete with tetraequivalent impairment should be allowed to compete" (72%), "Athletes with cerebral palsy and other coordination impairments should be classified with a system different than the current one" (75%), and "The maximal value for trunk should be increased from 1.0 to 1.5" (67%). A minority stated, "Wheelchair rugby should only be open to spinal cord injury and other neurological conditions" (36%) and "There should be a 4.0 class" (33%). Results strongly indicated that athletes and stakeholders want adjustments to the classification system in two areas: a focus on evaluation of athletes with impairments other than loss of muscle power caused by spinal cord injury and changes in classification of trunk impairment.

Movement and physiological demands of international and regional men's touch Rugby matches.

This study compared the internal and external match demands imposed on international and regional standard male touch rugby players. The study adopted a cohort design with independent groups. Twelve international players (mean age, 27.8 ± 6.2 years; body mass, 72.8 ± 3.7 kg; stature, 174.5 ± 5.4 cm) and 9 regional players (mean age, 25.5 ± 5.5 years; body mass 74.2 ± 7 kg; stature 174.1 ± 7 cm) were analyzed during 9 competitive matches from the 2013 season. Movement demands were measured using a 5-Hz global positioning system, alongside heart rate (HR) and session rating of perceived exertion (s-RPE) to quantify internal load. Total distance covered by international players was lower than regional players (2265.8 ± 562.3 cf. 2970 ± 558.9 m; p ≤ 0.05). However, international players had greater relative distance (137.1 ± 13.6 cf. 126.2 ± 17.2 m·min) due to shorter playing times per match (p ≤ 0.05). Absolute high-speed running (>14 km·h) was not different between groups (p > 0.05), but relative high-speed running (39.3 ± 12.0 cf. 26.0 ± 13.6 m·min) was higher for international players. Regional players performed more absolute low-speed activity (≤14 km·h) than international players (p ≤ 0.05), whereas relative low-speed activity was not different between groups (p > 0.05). Very high-speed running (>20 km·h) distance, bout number and frequency, peak, and average speed were all greater in international players (p ≤ 0.05). Higher average HR, summated HR, and s-RPE (p ≤ 0.05) indicated higher internal loads during matches for regional players. These data indicate that performance in men's touch rugby is characterized by more relative high-speed running and better repeated sprint capacities in higher standard players.

Comparison of running characteristics and heart rate response of international and national female rugby sevens players during competitive matches.

This study compared the activity profile of national and international female rugby sevens players during competitive matches. Twenty rugby sevens female players were recruited, 10 were members of the Spanish National Team (26.27 ± 4.05 years, 65.39 ± 5.01 kg, 166.72 ± 6.70 cm) and 10 were amateur athletes from a Spanish rugby championship (32.12 ± 6.40 years, 66.48 ± 5.38 kg of body mass, 167.37 ± 3.02 cm). Data collection was conducted over 4 matches in each of the 2 tournaments, national and international. Distance, velocity, and heart rate (HR) were recorded using global positioning system devices for all participants throughout each match. There were significant differences (p < 0.01) in total distance (1642 ± 171 vs. 1363 ± 222 m), average speed (6.0 ± 0.3 vs. 5.2 ± 0.6 km·h-1), number of sprints (6.1 ± 3.1 vs. 1.9 ± 1.4 sprints), and distance covered in sprinting (118.8 ± 61.4 vs. 47.0 ± 38.8 m). Significant differences were found at >95% maximum HR (HRmax), both for the first (p < 0.01) and second half (p ≤ 0.05). The work-rest ratio was significantly different (p < 0.01) between international (1:0.3) and national players (1:0.4). Significant differences were found in accelerations above 2 m·s-2 in the first and second half between the 2 groups. These findings suggest that distance covered in a match and speed are considerably different between international and national rugby sevens players, and this is reflected as higher intensity of play with consequently higher HR. Coaches may use this information to design specific running drills for this athlete population to match the requirements of national or international game play.