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

Seasonal Variation and Positional Differences in Anthropometry, Strength, and Power Characteristics in English Premiership Women's Rugby Union Players

ABSTRACT

Yao, X, Austerberry, A, Bishop, C, Wilson, L, Chiang, C-Y, and Turner, A. Seasonal variation and positional differences in anthropometry, strength, and power characteristics in English premiership women's rugby union players. J Strength Cond Res 38(5): 924-931, 2024-Women's rugby is a collision sport that relies heavily on body composition and physical characteristics of strength and power to achieve competitive success. Furthermore, the seasonal nature presents a variety of physical challenges that can cause fluctuations in a player's physical development. Therefore, the purpose of this study was to determine the differences in anthropometry, strength, and power characteristics between forwards and backs in women's rugby union athletes in England and to identify changes throughout a season. Forty-seven players were recruited from the English premiership women's rugby during the 2020-2021 season. Players were split into forwards and backs and underwent body composition testing by dual-energy X-ray absorptiometry and strength and power tests (countermovement jump, drop jump [DJ], and isometric midthigh pull) on 3 separate occasions (preseason, midseason, postseason). Overall, forwards had significantly ( p < 0.01) higher body mass, fat mass, lean mass [LM], bone mineral content, and take off momentum, and backs had significantly higher ( p < 0.01, d > 0.5) jump height, reactive strength, and shorter DJ contact time. When observing seasonal changes, there were statistically significant differences ( p < 0.01) or moderate-to-large practical differences ( d > 0.5) in LM, reactive strength index modified, time to take-off, and DJ flight time [FT] among forwards when comparing 3 testing time frames. For backs, statistically significant differences ( p < 0.01) or moderate-to-large practical differences ( d > 0.5) were reported in LM and DJ FT throughout the season. In conclusion, the strength and power testing and characteristics shown in this study could support coaches and junior women's rugby athletes to have a basic understanding of English premiership physical standards.

The Influence of Full-Time Holistic Support Delivered by a Sports Nutritionist on Within-Day Macronutrient Distribution in New Zealand Provincial Academy Rugby Union Players

Dietary intake is an important consideration for rugby union ('rugby') players to ensure substrate provision for optimal performance and facilitate recovery. Within-day meal distribution is especially important for athletes, particularly those with congested schedules and multiple daily training sessions. In the present study, 10 provincial academy rugby players engaged in a holistic support protocol informed by behaviour-change techniques led by a full-time sports nutritionist. Dietary intake was estimated during a 4-week monitoring and 4-week intervention period using the remote food photography method on one high-volume training day (two training sessions) and two low-volume training days (≤1 training session) per week. Lean body mass did not change significantly in response to the intervention. Significant increases were observed for protein on both low-volume (breakfast, AM snack, evening snack) and high-volume (post-gym, AM snack, evening snack) training days. Carbohydrate intake post-intervention was significantly greater at the pre-gym eating occasion but lower at PM snack and dinner eating occasions on high-volume days. These data suggest that incorporating a holistic support protocol led by a sports nutritionist can influence within-day nutrient intake in rugby players; however, no change to lean body mass was observed, and the influence of these changes in nutrient intake on performance and recovery warrants further investigation.

Custom-Fitted Compression Garments Enhance Recovery From Muscle Damage in Rugby Players

ABSTRACT

Brown, F, Jeffries, O, Gissane, C, Howatson, G, van Someren, K, Pedlar, C, Myers, T, and Hill, JA. Custom-fitted compression garments enhance recovery from muscle damage in rugby players. J Strength Cond Res 36(1): 212-219, 2022-to evaluate the effects of custom-fitted compression garments (CG) on recovery from muscle damage in rugby players. Forty-five players were tested for lower-body strength, power, and indices of muscle damage before completing a damaging protocol (20 × 20-m sprints with 5-m deceleration, 100 drop jumps). Players were randomly assigned to wear either custom-fitted (CF, n = 13), or standard-sized CG (SSG, n = 16), or to receive sham ultrasound therapy (CON, n = 16) immediately after exercise. Players were retested immediately, then after 24 and 48 hours. Strength recovery was significantly different between groups (F = 2.7, p = 0.02), with only CF recovering to baseline values by 48 hours (p = 0.973). Time × condition effects were also apparent for creatine kinase activity (χ2 = 30.4, p < 0.001) and midthigh girth (F = 3.7, p = 0.005), with faster recovery apparent in CF compared with both CON and SSG (p < 0.05). Custom-fitted CG improved strength recovery and indices of muscle damage in rugby players, compared with controls and standard-sized garments. Athletes and coaches would be advised to use appropriately fitted CG to enhance strength recovery after damaging exercise.

Differences in Adiposity Profile and Body Fat Distribution between Forwards and Backs in Sub-Elite Spanish Female Rugby Union Players

The purpose of this study was to analyze the adiposity profile and the body fat distribution in 56 sub-elite female rugby union players involved in the Spanish National Women's Rugby Union Championships. The participants included in this study, which was the first to analyze sub-elite players, show thinner skinfolds, lower fat mass, and lesser fat percentage than previously reported for elite female rugby union players. Forwards were heavier and had higher body mass index (BMI) and fat mass, thicker skinfolds, and higher fat percentage than back players. Forwards also possessed significantly greater total fat-free mass than backs. All these differences were applicable only to players under 25 years of age. A negative correlation between age and both abdominal and lower extremity fat was found in forward players but not in the backs. Both Yuhasz and Faulkner equations tended to underestimate fat percentage in comparison to Reilly equation. Although Yuhasz equation provided higher systematic error, random error was lower in comparison to Faulkner equation. This study shows the relevance of analyzing and monitoring adiposity in female rugby union players to optimize adaptation to the sports requirements of different playing positions and age.

Exploratory evaluation of muscle strength and skin surface temperature responses to contemporary cryotherapy modalities in sport

BACKGROUND: The effects of contemporary cryo-compression devices on function are limited compared to traditional applications of cooling. Development of cooling protocols are warranted. OBJECTIVE: To investigate the effects of three different cryo-compressive modalities applied at the knee on the isokinetic strength of the quadriceps over a re-warming period. METHODS: Eleven healthy male participants took part (23 ± 14 years; 78.3 ± 14.5 Kg; 180 ± 9.5 cm) randomly assigned to receive all modalities (Game Ready® (GR), Swellaway® (SA), Wetted Ice (WI)) applied for 15-min, separated by 1-week. Skin surface temperature (Ts⁢k) via thermography and the concentric peak moment (PM) of the quadriceps at 60 and 180∘/s were collected pre-, immediately-post and at 20-min post-intervention. RESULTS: Significant reductions occurred in Ts⁢k across all timepoints for all modalities (p=⩽ 0.05). Significant reductions in PM for WI were noted across all timepoints and PM for GR and SA immediately-post (p=⩽ 0.05) only. CONCLUSION: Precaution for immediately returning to sport following cryotherapy is required and influenced by type of cooling on muscle strength responses. Alternate targeted treatment modalities to minimise deferred deleterious effects on muscle strength may be considered. Research into length of application, periodisation and location is warranted for the development of such contemporary cryo-compressive modalities in applied practice.

Simple anthropometry-based calculations to monitor body composition in athletes: Scoping review and reference values

BACKGROUND

Kinanthropometry offers to exercise and health professionals a standardized procedure of acquiring surface anatomical measurements that might be used to track changes in body composition.

AIM

To describe simple anthropometric indices to monitor body composition changes in amateur and elite athletes, and to provide reference values during the competition phase.

METHODS

A search of articles indexed in PubMed/MEDLINE, ScienceDirect, Cochrane, and SciELO databases using the string body composition AND (anthropometric OR skinfolds OR circumferences OR girth OR estimation equation) AND "body fat". Inclusion criteria were: quantitative and/or qualitative research published between 2009 and 2020, written in English or Spanish, reporting simple anthropometric indices that included skinfolds, girths, or basic measures in amateur and elite athletes.

RESULTS

A total of 51 studies (Price's index = 66.4%) met all the inclusion criteria and were included in this scoping review. Contrary to the frequent practice, the use of a regression equation might not be accurate to evaluate body composition. To avoid this, anthropometrists should base their analysis on the absolute values of the sum of skinfolds (∑S) and related variables, such as skinfold-corrected girths and lean mass index. While not definitive, because further research is required, the practical recommendations and updated reference values in competition phase provided by this review would contribute to the accurate identification of body composition changes.

CONCLUSIONS

∑S and lean mass index have been shown to be valid for monitoring changes in fat mass and fat-free mass, respectively. More research is needed to derive the lean mass index-specific coefficient for each sports population.

Identifying Contextual Influences on Training Load: An Example in Professional Rugby Union

ABSTRACT

Dalton-Barron, NE, McLaren, SJ, Black, CJ, Gray, M, Jones, B, and Roe, G. Identifying contextual influences on training load: an example in professional rugby union. J Strength Cond Res 35(2): 503-511, 2021-We aimed to investigate the contextual factors influencing training load (TL), as determined by session rating of perceived exertion (sRPE-TL), accumulated within a match-to-match microcycle in rugby union players. Session rating of perceived exertion-TL data were collected daily from 35 professional rugby union players from the same team in the English Championship over the course of an in-season period. Players were split by positional groups (backs and forwards) and sRPE-TL data were categorized as: field-based on-feet sRPE-TL (sRPEField-TL), gym-based sRPE-TL (sRPEGym-TL), and the total summation of both (sRPETotal-TL). Three 2-level linear mixed models were built for each dependent variable in each positional group, with magnitude-based inferences applied. Long between-match recovery cycles (≥7 days) resulted in very likely to almost certainly small to moderate increases in sRPE-TL for all modalities and positions (fixed effect [mean range] = 28.5%-42.0%), apart from sRPEField-TL for forwards. For backs, there was a very likely small decrease in sRPEField-TL as the season progressed (-16.7% per trimester). Losing the last league match was associated with very likely and almost certainly small decreases in sRPETotal-TL and sRPEGym-TL for backs (-20.7% and -36.4%, respectively). Losing the last match in any competition resulted in a very likely small increase in sRPEField-TL (21.2%) and a possibly small decrease sRPEGym-TL (-18.5%) for backs-with a likely smaller sRPEGym-TL for forwards (-33.4%). The strength of the upcoming opposition had no effect on sRPE-TL. Our findings highlight some of the multifactorial contextual factors that must be considered when planning and evaluating training microcycles.

Short and long-term differences in anthropometric characteristics and physical performance between male rugby players that became professional or remained amateur

Objective

The objective of this study was to investigate which anthropometric and physical performance variables characterised players that advanced to professional teams (professionals) and how these variables changed over time, compared to those that did not secure professional contracts (i.e. remained amateurs).

Methods

Differences in anthropometry, strength, speed, power and intermittent running ability in 83 male rugby players collected between 2015 and 2019 were determined using repeated measures analysis.

Results

When arriving for the first year of the program, forwards that went on to become professional players were older (0.4 ± 0.3 yr, mean ± 95% CI, p = 0.004), heavier (4.6 ± 2.5 kg, p < 0.001) and stronger (range 6.2-16.4%) than forwards that remained amateur. Professional forwards were also slower at sprinting (range -2.7-2.9%, p < 0.001) and had lower Yo-Yo IRT L1 (-10.8%, p = 0.03). When first arrived on the program, professional backs were taller (3.5 ± 1.8 cm, p < 0.001), heavier (4.6 ± 2.4 kg, p < 0.001) and faster over 20 m (-1.9 ± 1.7%, p = 0.03) and 30 m (-1.7 ± 1.6%, p = 0.04) compared to amateurs. Compared to amateurs, professionals had a smaller increase in body mass (-4.2 ± 2.0%, p < 0.001) and greater improvement in sprinting (3.7, 2.8, 2.8% over 10, 20 and 30-m, respectively) and Yo-Yo IRT L1 (14.7 ± 11.0%, p = 0.05) over 3 years training.

Conclusion

Characteristics that are likely to assist players in becoming professionals include being older, heavier, taller and stronger.

Body composition differences by age and playing standard in male rugby union and rugby league: A systematic review and meta-analysis

This systematic review and meta-analysis aimed to determine differences in body compositionn between playing standard and age in male rugby union and rugby league athletes. The MOOSE (Meta-analysis of Observational Studies in Epidemiology) guidelines for design, implementation, and reporting were followed. Studies were required to be in male rugby union or league and have body composition as the primary or secondary outcome. Data was required to be presented separately for positional groups and body composition presented as whole-body. A systematic search was performed in PubMed, Cochrane Library, MEDLINE, SPORTDiscus, and CINHAHL via EBSCOhost. 57 studies were included for meta-analysis. Results highlighted significantly higher fat-free mass in senior elite than senior sub-elite or junior elite athletes for all RU and RL forwards. Small and non-significant differences were found in fat mass between rugby union playing standards and age categories. Rugby league senior elite forwards had less fat mass than junior elite forwards. Practitioners should prioritise training and nutritional strategies that maximise fat-free mass development, especially in junior elite cohorts.

COMPARISON OF CRYOTHERAPY MODALITY APPLICATION OVER THE ANTERIOR THIGH ACROSS RUGBY UNION POSITIONS; A CROSSOVER RANDOMIZED CONTROLLED TRIAL

BACKGROUND

In deliberation of the diverse physical traits of rugby union and the known interference adipose tissue has on the ability to cool deeper tissues, evidence is required to understand the effect of cryotherapy modalities to provide optimum outcomes post-injury.

PURPOSE

To investigate differences in the cooling ability of three different cryotherapy modalities in a rugby union population in an attempt to describe optimum cooling protocols for the anterior thigh.

STUDY DESIGN

Within-subjects randomized control crossover.

METHODS

Twenty-one healthy male rugby union players took part. Skin surface temperature measured via thermal imaging camera (ThermoVision A40M, Flir Systems, Danderyd, Sweden) alongside Thermal Comfort and Sensation questionnaires following interventions of either Wetted Ice (WI), Crushed Ice (CI) applied in a polythene bag secured by plastic wrap, or CryoCuff® (CC), applied for 20-minutes over the anterior thigh. Participants were grouped by their typical playing position for the sport of rugby union; i.e. forwards and backs.

RESULTS

Significant differences (p=<0.05) in T _sk for all modalities compared to baseline and comparing post T _sk between CI and CC (p=0.01) and WI to CC (p=0.01) were displayed. Significantly greater reductions in T _sk noted immediately-post in the 'forwards' group (p=≤0.05) compared to the 'backs' group for, all modalities (p=≤0.05). Thermal Comfort and Sensation scores demonstrated significant changes baseline compared to post for all modalities (p=<0.05). No significant differences were found when comparing between modalities for Thermal Comfort (p=0.755) or Sensation (p=0.225) for whole group or between positional groups.

CONCLUSIONS

Physiological responses to cooling differed across modalities with WI producing the greatest decrease in T _sk. Significant variability in T _sk was also displayed between positional factions. Results uphold the importance of the individualization of local cooling protocols when considering physical traits and characteristics within a rugby union population. Findings provide further understanding of the physiological responses to cooling through T _sk quantification in specific populations, helping to guide sports medicine practitioners on optimal cooling application development in sport.

LEVEL OF EVIDENCE

Level 2b.

Unique Finite Element Modelling of Human Body Inside Accelerating Car to Predict Accelerations and Frequencies at Different Human Segments

The comfort level of the human occupant inside a dynamic vehicle is dependent on the level of vibration generated inside the different segments of the human body. Some technologies have been developed to provide the final level of vibration inside an automotive-seated human, but those technologies considered only a specific portion of human segments. In the present work, a unique and comprehensive finite element simulation model was proposed to predict the final level of vibration at different segments of a seated human driver inside a moving car. The main aim of this unique simulation methodology was to replace the time-consuming and expensive real life vibration testing for a car-seated human body, with a non-robust and correctly postured virtual human model in a finite element environment. The output of this research work focused on the vertical accelerations, vertical displacement, and frequency, and the results obtained from this research work were validated through comparison to real life test data and information provided in other similar research works. The validation study showed that this unique simulation methodology can successfully be implemented to anticipate accelerations and frequencies at different points of a car-seated human body in order to optimize human health, comfort, and safety.

Seasonal Change in Body Composition and Physique of Team Sport Athletes

Walker, EJ, Aughey, RJ, McLaughlin, P, and McAinch, AJ. Seasonal change in body composition and physique of team sport athletes. J Strength Cond Res XX(X): 000-000, 2020-Body composition of team sport athletes was measured at 3 points across the preseason and competitive season. This repeated-measures study was conducted in 46 professional Australian football (AF) (age 23.8 ± 3.8 years), 26 soccer (age 22.7 ± 4.7 years), and 33 rugby union players (age 28.1 ± 4.2 years). A mixed-design analysis of variance was used to determine change across the season, and Pearson's correlation was used to determine the relationship between different measures. Anthropometry, dual-energy x-ray absorptiometry (DXA), and 3-dimensional (3D) scan technology were used in AF and soccer, whereas only DXA was used in rugby. Body mass remained unchanged for both AF and soccer with gains in lean mass (p < 0.01), from preseason to early in the competitive season. Skinfold measures declined in AF (p < 0.001) and soccer (p < 0.05) across the season, whereas DXA-measured fat mass only declined in soccer (p < 0.01). Rugby backs (p < 0.01) and forwards (p < 0.001) reduced body fat and gained lean mass from preseason to in-season with forwards having greater relative and absolute changes as measured by DXA. 3D technology did not show change across the season. Dual-energy x-ray absorptiometry body fat percent and the sum of skinfold correlation were large (r = 0.74 [p < 0.001, CI 0.67-0.81]). The greatest change in body composition occurs from the beginning of preseason to the start of competition, with changes returning to baseline levels toward the end of season. Dual-energy x-ray absorptiometry and skinfold measures were moderately correlated, providing a good alternative to track change in subcutaneous fat in AF and soccer athletes.

Position-Specific Body Composition Values in Female Collegiate Rugby Union Athletes

Harty, PS, Zabriskie, HA, Stecker, RA, Currier, BS, Moon, JM, Richmond, SR, Jagim, AR, and Kerksick, CM. Position-specific body composition values in female collegiate rugby union athletes. J Strength Cond Res XX(X): 000-000, 2019-Rugby union is a full-contact, intermittent team sport. Anthropometric characteristics of rugby union athletes have been shown to influence suitability for a given position and affect performance. However, little anthropometric data exist in female rugby union athletes. Thus, the purpose of this study was to report position-specific anthropometric, body composition, and bone density values in female collegiate rugby union athletes and to identify between-position differences in these variables. This investigation was a cross-sectional study involving 101 female collegiate rugby union athletes, categorized as forwards and backs as well as by position (props, hookers, locks, flankers, number 8 forwards, halfback, fly-half, centers, wings, and fullbacks). Anthropometric characteristics of all athletes were measured, and body composition was assessed via dual-energy x-ray absorptiometry. Outcome variables included age, height, body mass, BMI, body fat percentage, fat mass (FM), FM index, fat-free mass (FFM), FFM index, lean soft tissue, bone mineral content, bone mineral area, and bone mineral density. Anthropometric and body composition differences between forwards and backs were identified via independent t-tests and Mann-Whitney U tests, depending on normality of the variable. Between-position differences were assessed using one-way analysis of variances (ANOVAs) with Tukey post-hoc comparisons or Welch's ANOVA with Dunnett's T3 post-hoc test. Significant differences (p < 0.014) were identified between forwards and backs for every anthropometric variable, with forwards displaying greater height (167.7 ± 7.2 cm), body mass (81.5 ± 15.1 kg), and body fat percentage (28.2 ± 6.1%) relative to backs (164.5 ± 5.1 cm; 64.5 ± 7.7 kg; 21.9 ± 3.7%). Likewise, significant differences were identified for every anthropometric variable between several positions (p < 0.01). Significant (p < 0.05) interposition differences were identified within the subgroup of forwards, but not within the subgroup of backs. The present investigation is the first to report position-specific anthropometric and body composition data in female collegiate rugby union athletes. The results of this study can be used by rugby union coaches for recruiting and personnel decisions, to determine a player's suitability for a given position, and to further inform training and nutritional interventions in this population.

Upper and lower thresholds of fat-free mass index in a large cohort of female collegiate athletes

Fat-free mass index (FFMI) is a height-adjusted metric of fat-free mass which has been suggested as a useful method of body composition assessment in athletic populations. The purpose of this study was to determine sport-specific FFMI values and the natural upper threshold of FFMI in female athletes. 372 female collegiate athletes (Mean±SD; 20.03±1.55 years, 167.55±7.50 cm, 69.46±13.04 kg, 24.18±5.48% bodyfat) underwent body composition assessment via dual-energy x-ray absorptiometry. FFMI was adjusted to height via linear regression and sport-specific reference values were determined. Between-sport differences were identified using one-way ANOVA with Tukey post-hoc tests. Average FFMI was 18.82±2.08 kg/m²; height-adjusted values were not significantly different (p<0.05) than unadjusted values. FFMI in rugby athletes (20.09±2.23 kg/m²) was found to be significantly higher (p<0.05) than in gymnastics (18.62±1.12 kg/m²), ice hockey (17.96±1.04 kg/m²), lacrosse (18.58±1.84 kg/m²), swim & dive (18.16±1.67 kg/m²), and volleyball (18.04±1.13 kg/m²). FFMI in cross country (16.56±1.14 kg/m²) and synchronized swimming (17.27±1.47 kg/m²) was significantly lower (p<0.05) than in Olympic weightlifting (19.69±1.98 kg/m²), wrestling (19.15±2.47 kg/m²), and rugby. The upper threshold for FFMI in female athletes (97.5^th percentile) was 23.90 kg/m². These results can be used to guide personnel decisions and assist with long-term body composition, training, and nutritional goals.

Longitudinal Changes in Body Composition Assessed Using DXA and Surface Anthropometry Show Good Agreement in Elite Rugby Union Athletes

Rugby union athletes have divergent body composition based on the demands of their on-field playing position and ethnicity. With an established association between physique traits and positional requirements, body composition assessment is routinely undertaken. Surface anthropometry and dual-energy X-ray absorptiometry (DXA) are the most common assessment techniques used, often undertaken synchronously. This study aims to investigate the association between DXA and surface anthropometry when assessing longitudinal changes in fat-free mass (FFM) and fat mass (FM) in rugby union athletes. Thirty-nine elite male rugby union athletes (age: 25.7 ± 3.1 years, stature: 187.6 ± 7.7 cm, and mass: 104.1 ± 12.2 kg) underwent assessment via DXA and surface anthropometry multiple times over three consecutive international seasons. Changes in the lean mass index, an empirical measure to assess proportional variation in FFM, showed large agreement with changes in DXA FFM (r = .54, standard error of the estimate = 1.5%, p < .001); the strength of association was stronger among forwards (r = .63) compared with backs (r = .38). Changes in the sum of seven skinfolds showed very large agreement with changes in DXA FM (r = .73, standard error of the estimate = 5.8%, p < .001), with meaningful differences observed regardless of ethnicity (Whites: r = .75 and Polynesians: r = .62). The lean mass index and sum of seven skinfolds were able to predict the direction of change in FFM and FM 86% and 91% of the time, respectively, when DXA change was >1 kg. Surface anthropometry measures provide a robust indication of the direction of change in FFM and FM, although caution may need to be applied when interpreting magnitude of change, particularly with FM.

Four-Week Unstructured Break Improved Athletic Performance in Collegiate Rugby Players

Jensen, CD, Gleason, D, and VanNess, JM. Four-week unstructured break improved athletic performance in collegiate rugby players. J Strength Cond Res 32(6): 1671-1677, 2018-This study analyzed the changes in athletic performance and anthropometric characteristics in collegiate male club rugby athletes (n = 14) after a 4-week winter break. All measurements were collected before and after the break. Body composition was assessed by body mass index and hydrostatic weighing. Performance measurements were as follows: V[Combining Dot Above]O2max, vertical jump, 10-yard sprint, squat max, and bench press max. Before testing, each subject was acclimated to the protocols to reduce learning effects. During the 4-week break, no workouts were provided for the athletes; it was unsupervised and unstructured. Participants were required to maintain and submit self-reported nutritional and activity logs during this period. After the break, the athletes demonstrated a 5.0% improvement in V[Combining Dot Above]O2max (absolute increase of 2.25 ml·kg·min), 6.8% improvement in vertical jump (1.50 inches), and a 14.3% increase in squat max (38.64 lb). Although increases in body mass (1.0%) were not significant, the body fat percentage exhibited a relative increase of 19.3% (absolute change from 13.35 to 15.93%). A significant discriminate function analysis indicated statistical differences between groups based on these variables. Self-reported behavior logs confirmed participation in >3 days of moderate to intense physical activity per week but somewhat poor dietary habits. These results indicate that collegiate rugby athletes may not need prescribed exercise routines during seasonal breaks in the athletic schedule. However, it may be beneficial to provide structured nutritional advice during unsupervised periods.

Combined individual scrummaging kinetics and muscular power predict competitive team scrum success

Scrummaging is a major component of Rugby Union gameplay. Successful scrummaging is dependent on the coordination of the forward players and the strength of the eight individuals. The study aim was to determine whether individual scrummaging kinetics and other candidate factors associated with scrummaging performance discriminate team scrum performances. Sixteen club-level forwards (stature: 1.80 ± 0.1 m; mass: 99.0 ± 18.2 kg) were initially divided into two scrummaging packs. A total of 10 various scrum permutations were tested, where players were randomly swapped between the two packs. Winning scrums were determined by two observers on opposite sides of the scrum. Fatigue (100 mm visual analogue scale (VAS)) and scrummaging effort (6-20 rating of perceived exertion (RPE)) were assessed following each scrum contest. Individual scrummaging kinetics were acquired through an instrumented scrum ergometer and muscular power indicated through vertical jump heights. Student's t-tests were used to differentiate between winning and losing scrum packs. VAS and RPE were assessed using repeated measures ANOVAs. Winning scrum packs had significantly larger combined force magnitudes (p < .002), regardless of the player contribution calculations. Additionally, winning packs had less individual movement (p = .033) and higher combined vertical jump heights (p < .001) but were not significantly heavier (p = .759) than losing scrum packs. While perceived VAS and RPE values progressively increased (p < .001), no differences in the individual scrum magnitudes were observed between the 1st and 10th scrum (p = .418). The results indicated that the combination of individual forces, variation in movement and factors related to scrummaging performance, such as vertical jump height, were associated with team scrummaging success.

Three-Compartment Body Composition Changes in Professional Rugby Union Players Over One Competitive Season: A Team and Individualized Approach

The purpose of this study was to investigate the longitudinal body composition of professional rugby union players over one competitive season. Given the potential for variability in changes, and as the first to do so, we conducted individual analysis in addition to analysis of group means. Thirty-five professional rugby union players from one English Premiership team (forwards: n = 20, age: 25.5 ± 4.7 yr; backs: n = 15, age: 26.1 ± 4.5 yr) received one total-body dual-energy X-ray absorptiometry scan at preseason (August), midseason (January), and endseason (May), enabling quantification of body mass, total and regional fat mass, lean mass, percentage tissue fat mass (%TFM), and bone mineral content (BMC). Individual analysis was conducted by applying least significant change (LSC), derived from our previously published precision data and in accordance with International Society for Clinical Densitometry guidelines. Mean body mass remained stable throughout the season (p > 0.05), but total fat mass and %TFM increased from pre- to endseason, and from mid- to endseason (p <0.05). There were also statistically significant increases in total-body BMC across the season (p <0.05). In both groups, there was a loss of lean mass between mid- and endseason (p <0.018). Individual evaluation using LSC and Bland-Altman analysis revealed a meaningful loss of lean mass in 17 players and a gain of fat mass in 21 players from pre- to endseason. Twelve players had no change and there were no differences by playing position. There were individual gains or no net changes in BMC across the season for 10 and 24 players, respectively. This study highlights the advantages of an individualized approach to dual-energy X-ray absorptiometry body composition monitoring and this can be achieved through application of derived LSC.

Seasonal changes in body composition of inter-county Gaelic Athletic Association hurlers

Longitudinal change in body composition for elite-level inter-county hurlers was reported over a single season and four consecutive seasons. Body composition measured by dual-energy x-ray absorptiometry (DXA) of 66 senior, male, outfield players was obtained. Four successive measurements were taken: off-season (OFF₁), pre-season (PRE), mid-season (MID) and the off-season of the following season (OFF₂). A subsample of 11 hurlers were measured at all time points over 4 consecutive seasons. DXA-derived estimates of fat and lean mass were normalised to stature for analysis (kg∙m^‒2); data are (mean [lower: upper, 95% confidence interval]). A concurrent increase of lean mass (0.31 [0.19: 0.43] kg∙m^‒2) and loss of fat mass occurred (-0.38 [-0.50: -0.26] kg∙m^‒2) OFF₁ to PRE. Lean mass accrual was maintained PRE to OFF₂ while the initial loss of fat mass was restored MID to OFF₂ (0.52 [0.40: 0.64] kg ∙ m^‒2), with the trunk acting as the primary region of change. Over the four seasons, a net increase of lean mass was observed (~ 0.9 [0.4: 1.4] kg per annum) with a negligible overall change for fat mass over time. However, the cycling of fat mass (OFF to PRE and MID to OFF) within each season was recurrent season-to-season.

Does Stature or Wingspan Length Have a Positive Effect on Competitor Rankings or Attainment of World Title Bouts in International and Elite Mixed Martial Arts?

In this study the stature, wingspan and stature-to-wingspan ratio (S:W) was recorded for N = 474 elite and international mixed martial arts (MMA) competitors who appeared in televised bouts over the course of one calendar year. Each weight division was split into three or four ranking groups (RG) depending on division size, as well as into groups depending on if the competitors had won or competed for a world title (El) or had done neither (In). One-way ANOVA (≤0.05) found that shorter competitors are ranked higher in flyweight and in the middle in women’s strawweight. Independent t-tests (≤0.05) found that shorter competitors also have more chance of winning or competing for a world title in featherweight and flyweight. Independent t-tests (≤0.05) also found a significant difference between males and female for S:W. There was a weak, negative correlation and a moderate, negative correlation between stature and rank in lightweight and light heavyweight respectively and a moderate, negative correlation between S:W and rank in featherweight. There were no other significant differences found. Overall, whilst MMA competitors have a S:W of 1:1.024, due to the paucity of significant differences found, it was determined that anthropometrical measurements cannot be used to predict success in elite and international mixed martial arts.

The Diet Quality of Competitive Adolescent Male Rugby Union Players with Energy Balance Estimated Using Different Physical Activity Coefficients

Objectives: The aims of the current study were to comprehensively assess the dietary intakes and diet quality of a sample of Australian competitive adolescent rugby union players and compare these intakes with National and Sports Dietitians Association (SDA) Recommendations for adolescent athletes. A secondary aim investigated applying different physical activity level (PAL) coefficients to determine total energy expenditure (TEE) in order to more effectively evaluate the adequacy of energy intakes. Design: Cross-sectional. Methods: Anthropometrics and dietary intakes were assessed in 25 competitive adolescent male rugby union players (14 to 18 years old). Diet was assessed using the validated Australian Eating Survey (AES) food frequency questionnaire and diet quality was assessed through the Australian Recommended Food Score. Results: The median dietary intakes of participants met national recommendations for percent energy (% E) from carbohydrate, protein and total fat, but not carbohydrate intake when evaluated as g/day as proposed in SDA guidelines. Median intakes of fibre and micronutrients including calcium and iron also met national recommendations. Overall diet quality was classified as ‘good’ with a median diet quality score of 34 (out of a possible 73); however, there was a lack of variety within key food groups including carbohydrates and proteins. Non-core food consumption exceeded recommended levels at 38% of the daily total energy intake, with substantial contributions from takeaway foods and sweetened beverages. A PAL coefficient of 1.2–1.4 was found to best balance the energy intakes of these players in their pre-season. Conclusions: Adolescent rugby players met the percent energy recommendations for macronutrients and attained an overall ‘good’ diet quality score. However, it was identified that when compared to specific recommendations for athletes, carbohydrate intakes were below recommendations and these players in their pre-season reported high consumption of non-core foods, particularly sugar sweetened drinks and low intakes of vegetables.

Player's success prediction in rugby union: From youth performance to senior level placing

OBJECTIVES

The study questioned if and to what extent specific anthropometric and functional characteristics measured in youth draft camps, can accurately predict subsequent career progression in rugby union.

DESIGN

Original research.

METHODS

Anthropometric and functional characteristics of 531 male players (U16) were retrospectively analysed in relation to senior level team representation at age 21-24. Players were classified as International (Int: National team and international clubs) or National (Nat: 1st, 2nd and other divisions and dropout). Multivariate analysis of variance (one-way MANOVA) tested differences between Int and Nat, along a combination of anthropometric (body mass, height, body fat, fat-free mass) and functional variables (SJ, CMJ, t_15m, t_30m, VO_2max). A discriminant function (DF) was determined to predict group assignment based on the linear combination of variables that best discriminate groups. Correct level assignment was expressed as % hit rate.

RESULTS

A combination of anthropometric and functional characteristics reflects future level assignment (Int vs. Nat). Players' success can be accurately predicted (hit rate=81% and 77% for Int and Nat respectively) by a DF that combines anthropometric and functional variables as measured at ∼15 years of age, percent body fat and speed being the most influential predictors of group stratification.

CONCLUSIONS

Within a group of 15 year-olds with exceptional physical characteristics, future players' success can be predicted using a linear combination of anthropometric and functional variables, among which a lower percent body fat and higher speed over a 15m sprint provide the most important predictors of the highest career success.

Changes in Body Composition in Division I Football Players Over a Competitive Season and Recovery in Off-Season

This study investigated changes in body composition over 1 competitive football season in D-I collegiate football players (N = 53; by position, 21 linemen vs. 32 nonline; or by seniority, 30 upperclassmen vs. 23 underclassmen) and additional changes by the following spring season (N = 46; 20 linemen vs. 26 nonline; 27 upperclassmen vs. 19 underclassmen). Body composition by dual-energy x-ray absorptiometry (DXA) was completed pre- and post-season and the following spring. For the team as a whole, player weight decreased 1.3 kg (1.2%) and lean mass decreased 1.4 kg (1.6%) over the season. Absolute fat mass showed no change; however, percent body fat showed a 0.5% increase. There was an interaction between player position and seniority for changes in lean mass (p < 0.01). In nonline positions upperclassmen lost more lean mass than underclassmen, whereas in line positions underclassmen lost more lean mass than upperclassmen. Spring measures indicate that weight did not increase during the off-season, but improvement in body composition was noted. Lean mass increased by 2.2 kg (2.6%), whereas absolute fat mass decreased by 1.4 kg (6.7%). Although weight and lean mass losses during the competitive season were recovered in the off-season, changes in collegiate football programs that include nutrition counseling, dietary recommendations, monitoring of weight, and skin-fold testing as an estimate of body fat change would be beneficial to players. Strength and conditioning coaches and staff need to consider strategies to incorporate these practices into their programs.

Long-term training-induced changes in sprinting speed and sprint momentum in elite rugby union players

Speed and sprint momentum are considered to be important physical qualities for rugby. The purpose of the study was to understand the development of these qualities in senior and junior international rugby players. In part 1 of the study, a group of senior (n = 38) and junior (n = 31) players were tested for speed over 40 m. Initial sprint velocity (ISV), maximal sprint velocity (MSV), initial sprint momentum (ISM), and maximal sprint momentum (MSM) were calculated using 10-m splits. In part 2 of the study, a group of junior (n = 12) and senior (n = 15) players were tracked over a 2-year period for body mass, ISV, MSV, ISM, and MSM. In part 1, senior backs and forwards were not found to have significantly greater ISV and MSV than junior players but were found to have greater ISM and MSM. Forwards were found to have significantly greater ISM and MSM than backs but significantly lower ISV and MSV than backs. In part 2, no significant differences were found over the 2 years between senior and junior players, but greater effect sizes for juniors were generally found when compared with seniors for improvements in ISV (d = 0.73 vs. 0.79), MSV (d = 1.09 vs. 0.68), ISM (d = 0.96 vs. 0.54), and MSM (d = 1.15 vs. 0.50). Sprint momentum is a key discriminator between senior and junior players, and large changes can be made by junior players as they transition into senior rugby. Speed appears to peak for players in their early 20s but sprint momentum appears to be more trainable.

Body composition of female road and track endurance cyclists: Normative values and typical changes

The aims of this study were to describe normative values and seasonal variation of body composition in female cyclists comparing female road and track endurance cyclists, and to validate the use of anthropometry to monitor lean mass changes. Anthropometric profiles (seven site skinfolds) were measured over 16 years from 126 female cyclists. Lean mass index (LMI) was calculated as body weight × skinfolds(-x). The exponent (x) was calculated as the slope of the natural logarithm of body weight and skinfolds. Percentage changes in LMI were compared to lean mass changes measured using dual-energy X-ray absorptiometry (DXA) in a subset of 25 road cyclists. Compared to sub-elite and elite cyclists, world class cyclists were (mean [95% CI]) 1.18 kg [0.46, 1.90] and 0.60 kg [0.05, 1.15] lighter and had skinfolds that were 7.4 mm [3.8, 11.0] and 4.6 mm [1.8, 7.4] lower, respectively. Body weight (0.41 kg [0.04, 0.77]) and skinfolds (4.0 mm [2.1, 6.0]) were higher in the off-season compared to the early-season. World class female road cyclists had lower body weight (6.04 kg [2.73, 9.35]) and skinfolds (11.5 mm [1.1, 21.9]) than track endurance cyclists. LMI (mean exponent 0.15 [0.13, 0.18]) explained 87% of the variance in DXA lean mass. In conclusion, higher performing female cyclists were lighter and leaner than their less successful peers, road cyclists were lighter and leaner than track endurance cyclists, and weight and skinfolds were lowest early in the season. LMI appears to be a reasonably valid tool for monitoring lean mass changes.

Anthropometric and Three-Compartment Body Composition Differences between Super League and Championship Rugby League Players: Considerations for the 2015 Season and Beyond

Super League (SL) and Championship (RLC) rugby league players will compete against each other in 2015 and beyond. To identify possible discrepancies, this study compared the anthropometric profile and body composition of current SL (full-time professional) and RLC (part-time semi-professional) players using dual-energy X-ray absorptiometry (DXA). A cross-sectional design involved DXA scans on 67 SL (n=29 backs, n=38 forwards) and 46 RLC (n=20 backs, n=26 forwards) players during preseason. A one-way ANOVA was used to compare age, stature, body mass, soft tissue fat percentage, bone mineral content (BMC), total and regional (i.e., arms, legs and trunk) fat and lean mass between SL forwards, SL backs, RLC forwards and RLC backs. No significant differences in age, stature or body mass were observed. SL forwards and backs had relatively less soft tissue fat (17.5 ± 3.7 and 14.8 ± 3.6 vs. 21.4 ± 4.3 and 20.8 ± 3.8%), greater BMC (4,528 ± 443 and 4,230 ± 447 vs. 4,302 ± 393 and 3,971 ± 280 g), greater trunk lean mass (37.3 ± 3.0 and 35.3 ± 3.8 vs. 34.9 ± 32.3 and 32.3 ± 2.6 kg) and less trunk fat mass (8.5 ± 2.7 and 6.2 ± 2.1 vs. 10.7 ± 2.8 and 9.5 ± 2.9 kg) than RLC forwards and backs. Observed differences may reflect selection based on favourable physical attributes, or training adaptations. To reduce this discrepancy, some RLC players should reduce fat mass and increase lean mass, which may be of benefit for the 2015 season and beyond.

Body composition characteristics of elite Australian rugby union athletes according to playing position and ethnicity

This study describes the body composition traits of modern-day elite rugby union athletes according to playing position and ethnicity. Thirty-seven international Australian rugby athletes of Caucasian and Polynesian descent undertook body composition assessment using dual-energy X-ray absorptiometry and surface anthropometry. Forwards were significantly taller, heavier and had a greater total fat mass and lean mass than backs. Backs displayed a higher percentage lean mass and lower sum of seven skinfolds and percentage fat mass. While no whole body composition differences were seen between ethnicities, significant regional differences were observed. In the periphery (arm and leg) regions, Polynesians had a greater proportion of fat mass (53.1% vs. 51.3%, P = 0.052, d = 0.5) and lean mass (49.7% vs. 48.6%, P = 0.040, d = 0.9), while in the trunk region a lower proportion of fat mass (37.2% vs. 39.5%, P = 0.019, d = 0.7) and lean mass (45.6% vs. 46.8%, P = 0.020, d = 1.1). Significant differences were also seen between Caucasian and Polynesian forwards in leg lean mass (31.4 kg vs. 35.9 kg, P = 0.014, d = 2.4) and periphery lean mass (43.8 kg vs. 49.6 kg, P = 0.022, d = 2.4). Elite Polynesian rugby athletes have different distribution patterns of fat mass and lean mass compared to Caucasians, which may influence their suitability for particular positions.

Fitness profiles of elite portuguese rugby union players

The aim of this study was to describe the fitness profiles of senior elite Portuguese rugby players. Forty-six senior Portuguese rugby players, classified as backs (n=22; age 26.2±2.8) and forwards (n=24; age 26.7±2.9) were assessed during physical testing sessions carried out for the Portuguese National rugby team. The body composition, maximum strength and anaerobic capacity of players are hypothesized to be important physical characteristics as successful performance in rugby is predicated on the ability to undertake skilled behaviours both quickly and whilst withstanding large forces when in contact situations. No absolute differences were found between the backs and forwards for the speed performance variables although positional differences were found across all speeds when assessed relative to body mass since the forwards were significantly heavier. Coaches and the management team can use this information for monitoring progressive improvements in the physiological capacities of rugby players. These physical characteristics of elite rugby players provide normative profiles for specific positions and should form the basis of developmental programmes for adolescents.

Dual-energy X-ray absorptiometry measured regional body composition least significant change: effect of region of interest and gender in athletes

Dual-energy X-ray absorptiometry (DXA) is widely used to evaluate body composition in athletes. Knowledge of measurement precision is essential for monitoring body composition changes over time. This study begins characterizing DXA body composition precision in 60 (30 males and 30 females) Division 1 athletes focusing on gender, regional, and tissue type differences. Two total body scans with repositioning between were performed on the same day. Least significant change (LSC) for the root-mean-square deviation (LSCRMSD) and the percent coefficient of variation (LSC%CV) for total, lean, and fat mass was calculated for 6 regions of interest. The effect of gender, region, tissue type, and mass on the standard deviation (SD) and percent coefficient of variation (%CV) between the 2 scans was evaluated using repeated measures regression analysis. Statistically significant effects of gender, region, tissue type, and mass on SD and %CV were noted. To generalize, a nonlinear positive relationship between LSCRMSD and mass and a nonlinear negative relationship between LSC%CV and mass were observed. In conclusion, DXA body composition LSC varies among genders, regions, tissues, and mass. As such, when evaluating serial body composition in athletes, especially if assessing regional change, knowledge of precision in individuals of similar body size and gender to the population of interest is needed.

The Official Positions of the International Society for Clinical Densitometry: body composition analysis reporting

Dual-energy x-ray absorptiometry (DXA) measurements of body composition increasingly are used in the evaluation of clinical disorders, but there has been little guidance on how to effectively report these measures. Uniformity in reporting of body composition measures will aid in the diagnosis of clinical disorders such as obesity, sarcopenia, and lipodystrophy. At the 2013 International Society for Clinical Densitometry Position Development Conference on body composition, the reporting section recommended that all DXA body composition reports should contain parameters of body mass index, bone mineral density, BMC, total mass, total lean mass, total fat mass, and percent fat mass. The inclusion of additional measures of adiposity and lean mass are optional, including visceral adipose tissue, appendicular lean mass index, android/gynoid percent fat ratio, trunk to leg fat mass ratio, lean mass index, and fat mass index. Within the United States, we recommend the use of the National Health and Nutrition Examination Survey 1999-2004 body composition dataset as an age-, gender-, and race-specific reference and to calibrate BMC in 4-compartment models. Z-scores and percentiles of body composition measures may be useful for clinical interpretation if methods are used to adjust for non-normality. In particular, DXA body composition measures may be useful for risk-stratification of obese and sarcopenic patients, but there needs to be validation of thresholds to define obesity and sarcopenia. To summarize, these guidelines provide evidence-based standards for the reporting and clinical application of DXA-based measures of body composition.

Muscle imbalance among elite Australian rules football players: a longitudinal study of changes in trunk muscle size

CONTEXT

Trunk muscles, such as the transversus abdominis (TrA) and multifidus, play a key role in lumbopelvic stability, which is important in athletic performance. Asymmetry or imbalance in these and other trunk muscles could result from the specific requirements of the game of Australian rules football.

OBJECTIVE

To determine whether seasonal variations in the sizes of key trunk muscles associated with lumbopelvic stability occur in Australian Football League players.

DESIGN

Cross-sectional study.

SETTING

Hospital.

PATIENTS OR OTHER PARTICIPANTS

The number of players eligible to participate at each of the 4 time points was 36 at the start of preseason 1 (T1), 31 at end of season 1 (T2), 43 at the end of preseason 2 (T3), and 41 at the start of preseason 3 (T4). The group with data at all 4 time points (n = 20) was used in the analyses and was shown to be representative of the total sample.

INTERVENTION(S)

Magnetic resonance imaging was used to determine the cross-sectional areas (CSAs) of the multifidus (vertebral levels L2 to L5) and lumbar erector spinae (LES) muscles (L3), as well as the thickness of the TrA and internal oblique (IO) muscles at L3.

MAIN OUTCOME MEASURE(S)

Cross-sectional areas of the multifidus and LES muscles and thickness of the TrA and IO muscles.

RESULTS

By the end of the playing season, results showed 11.1% atrophy for multifidus CSA at L3 and 21% atrophy for TrA thickness at rest. In comparison, the CSA of the LES muscles increased by 3.6%, and the thickness of the IO muscle increased by 11.8% compared with the start of the preseason.

CONCLUSIONS

The results indicated an imbalance of the key muscles associated with lumbopelvic stability.

Changes in strength over a 2-year period in professional rugby union players

The purpose of this study was to assess the magnitude of upper and lower body strength changes in highly trained professional rugby union players after 2 years of training. An additional purpose was to examine if the changes in strength were influenced by the starting strength level, lean mass index (LMI), or chronological age. This longitudinal investigation tracked maximal strength and body composition over 3 consecutive years in 20 professional rugby union athletes. Maximal strength in the bench press and back squat and body composition was assessed during preseason resistance training sessions each year. The athletes completed a very rigorous training program throughout the duration of this study consisting of numerous resistance, conditioning and skills training sessions every week. The primary findings of this study were as follows: (a) Maximal upper and lower body strength was increased by 6.5-11.5% after 2 years of training (p = 0.000-0.002 for bench press; p = 0.277-0.165 for squat); (b) magnitude of the improvement was negatively associated with initial strength level (r = -0.569 to -0.712, p ≤ 0.05); (c) magnitude of improvement in lower body maximal strength was positively related to the change in LMI (an indicator of hypertrophy; r = 0.692-0.880, p ≤ 0.05); and (d) magnitude of improvement was not associated with the age of professional rugby union athletes (r = -0.068 to -0.345). It appears particularly important for training programs to be designed for continued muscle hypertrophy in highly trained athletes. Even in professional rugby union athletes, this must be achieved in the face of high volumes of aerobic and skills training if strength is to be increased.

The usefulness of densitometry as a method of assessing the nutritional status of athletes. Comparison with body mass index

The body mass index (BMI) is used to assess nutritional status. The result in athletes may be overestimated due to increase in muscle mass.

OBJECTIVE

To assess the usefulness of fat mass index (FMI) and lean mass index (LMI) determination as indicators of nutritional status and to compare the results with BMI.

MATERIAL AND METHODS

We studied 28 amateur rugby players, male. After being subjected to whole body densitometry by dual X-ray absorptiometry, we determined fat and lean body mass together with other parameters. FMI (fat in kg/height in meters(2)), LMI (lean in kg/height in meters(2)) and appendicular muscle mass index (AMMI, arms and legs musculature in kg/height in meters(2)) were calculated.

RESULTS

Using BMI, 18 players were overweight and 4 obese type I. Considering FMI, 7 of them had normal values and high LMI and AMMI, one of them changed from overweight to obese and another one from obese to overweight. Of the 6 players with normal BMI, one of them showed fat excess and another one fat defect. The results changed the assessment of nutritional status in 39% of players.

CONCLUSIONS

Although BMI is an appropriate parameter in general population for the assessment of nutritional status, in athletes should be taken into account fat and muscle body percentage and their corresponding indexes. The whole body densitometry appears to be a simple and reliable technique for this purpose.

Physiological, anthropometric, and performance characteristics of rugby sevens players

Although the characteristics of 15-a-side rugby union players have been well defined, there is little information on rugby sevens players.

PURPOSE

The authors profiled the anthropometric, physiological, and performance qualities of elite-level rugby sevens players and quantified relationships between these characteristics.

METHODS

Eighteen male international rugby sevens players undertook anthropometric (body mass, height, sum of 7 skinfolds, lean-mass index), acceleration and speed (40-m sprint), muscle-power (vertical jump), repeated-sprint-ability (6 × 30-m sprint), and endurance (Yo-Yo Intermittent Recovery test and treadmill VO2max) testing. Associations between measurements were assessed by correlation analysis.

RESULTS

Rugby sevens players had anthropometric characteristics (body mass 89.7 ± 7.6 kg, height 1.83 ± 0.06 m, sum of 7 skinfolds 52.2 ± 11.5 mm; mean ± SD) similar to those of backs in international 15-player rugby union. Acceleration and speed (40-m sprint 5.11 ± 0.15 s), muscle-power (vertical jump 66 ± 7 cm), and endurance (VO2max 53.8 ± 3.4 mL · kg-1 · min-1) qualities were similar to, or better than, those of professional 15-a-side players. Coefficients of variation ranged from 2.5% to 22%. Relative VO2max was largely correlated with Yo-Yo distance (r = .60, .21-.82; 90% confidence interval) and moderately correlated with 40-m sprint time (r = -.46, -.75 to -.02) and repeated-sprint ability (r = -.38, -.72 to .09).

CONCLUSIONS

International rugby sevens players require highly developed speed, power, and endurance to tolerate the demands of competition. The small between-athletes variability of characteristics in rugby sevens players highlights the need for relatively uniform physical and performance standards in contrast with 15-a-side players.

Agreement between anthropometric and dual-energy X-ray absorptiometry assessments of lower-limb volumes and composition estimates in youth-club rugby athletes

The purpose of this study was to assess the agreement of lower-limb volume estimates based on anthropometry and dual-energy X-ray absorptiometry (DXA) as a reference method in male rugby athletes. Predictive models using body mass and skinfolds were tested to improve the relative agreement between protocols (anthropometry, DXA). Rugby players (n = 41; 19.9 ± 2.2 years) volunteered for the study. Lower-limb total and fat-free volumes were estimated by anthropometry and also derived using DXA. Cross-validation between the anthropometry technique and DXA was then performed. Lower-limb volume estimates by anthropometry overestimated reference values and tended to be further from the reference values with the increase of scale. For the total sample, standard errors of measurement for volume estimates by anthropometry were 1.99 L and 1.34 L for total and fat-free volumes, respectively. Correlations with reference values were 0.81 for lower-limb volume and 0.90 for lower-limb fat-free volume. Correlations between estimated prediction equations and reference values showed higher correlations (r = 0.96 for lower-limb volume and r = 0.93 for lower-limb fat-free volume) compared with anthropometric estimates. Overall, the agreement of anthropometry method to quantify lower-limb volumes with DXA as a reference in young adult rugby players is acceptable and is a practical method when more expensive and complex techniques are not available. The consideration of body mass and lower-limb skinfolds increases the precision of lower-limb volume estimates using anthropometry in the young adult rugby players.

Bone mineral density and body composition of South African cricketers

Mechanical loading associated with weight-bearing physical activity has been positively associated with bone mineral density in athletes participating in various sports. The aim of this study was to compare the body composition and bone mineral density of South African male cricketers to controls. Whole body (WB), femoral neck (FN), proximal femur (PF) and lumbar spine (LS) BMD, as well as whole body fat mass (WBFM) and lean mass (WBLM) were measured, using dual-energy X-ray absorptiometry (DXA), on 34 high-performance (senior provincial and national level) cricketers and 23 physically active controls between the ages of 16 and 34 years. Cricketers were significantly younger, taller, and had greater WBLM and WBBMC compared to the controls. LS, PF and FN BMD were higher in the cricketers and controls before and after adjusting for age and height. WBBMD was significantly lower in the spin bowlers compared to the batsmen and fast bowlers, after adjusting for age and height; however, there were no differences at the BMD sites between the groups. Bone mineral density at the lumbar spine and hip sites was significantly greater in the cricketers compared to the controls, suggesting that the mechanical loading associated with cricket is beneficial for bone mineral density.

Somatic profile of competitive sport climbers

Since rock climbing grows in popularity, the number of the respective scientific reports increases. However, those concerning anthropometric profile of elite climbers are scarce and inconsistent, thus the aim of the study was to describe the anthropometric characteristics of competitive sport climbers. Male rock climbers (n = 21) aged 17 – 29 years took part in the study; their climbing ability ranged from 6b to 8c in the French scale. Body height, body mass, arm span, length and girths of both extremities, shoulder and pelvis widths, as well as thickness of 5 skinfolds were determined. From these, body mass index (BMI), body fat content and selected anthropometric indices were calculated. Data collected for climbers were compared with those of untrained students (n = 165) of Warsaw Technical University. Although no between-group differences were found for body height, body mass, BMI or body fat content, the climbers exhibited significantly (p<0.001) lower pelvis-to-shoulder ratio, longer lower extremities (p<0.05), and greater arm length and arm span (p<0.001) compared to untrained students. The results of this study do not support the view that climbers are small in stature and of low body mass. It seems that the core of the issue is not in body size but rather in specific body proportions and this may be of great importance in selecting subjects to competitive sport climbing.