Investigating the Emergence of Collective States Within Rugby Sevens Gameplay.

Rugby sevens is a small-sided variant of rugby union characterised by fast-moving, high-intensity gameplay and is an example of a team invasion sport, where players work together to achieve a shared goal of attacking and defending as a cohesive unit. The dynamics of such sports can be viewed as self-organizing systems, where individual players form collective patterns without a centralized mechanism of control. Inspired by the analysis of collective movement in animals, this novel study investigates the emergent patterns of order and disorder in sub-elite female rugby sevens using order parameters (typically used to analyse particle systems) to characterize the team's collective state during different phases of play. The findings demonstrate that defensive gameplay is more ordered, with more compact formations, compared to attacking play, and there is a correlation between alignment/order in player motion and group speed. The work further suggests that the collective states formed differ between sequences of play with different levels of ground gained by the attacking team. These observations provide a sound justification for player training with a focus on cohesive defensive movements to resist disruptions from opposing attackers, while employing attacking tactics that disrupt the cohesion and order of opposing teams.

Fatigue score as a promising complementary training monitoring tool: a pilot study in elite rugby sevens players.

The aim of this study was to compare physical and hormonal responses of seventeen elite rugby sevens players over a 6-week intense training block (IT) and a consecutive 2-week tapering period (TAP), using a fatigue cut-off score of 20 as a potential moderating variable. Training was monitored by daily training load (TL) and strain (TS) (using the session rating of perceived exertion [sRPE]) and also the weekly total score of fatigue (TSF; 8-item questionnaire tool). Testing and 24 h urinary cortisol (CL), cortisone (CN), adrenaline (AD) and noradrenalin (NAD) concentrations were also analysed before (T0) and after IT (T1) and after the TAP (T2). Players were assigned to group 1 with a TSF above 20 (G1 > 20, n = 9) and group 2 with a TSF below 20 (G2 < 20, n = 8) according to the French Society for Sports Medicine guidelines. TSF (effect size [ES] from 1.17 to 1.75), TL (ES from 0.81 to 1.06) and TS (ES from 1.23 to 1.40) were higher in G1 > 20 than in G2 < 20 over IT. Likewise, performance standards (ES from 1.58 to 2.61) and AD levels were lower (ES = 3.20), whereas CL and CL/CN ratio (ES from 1.60 to 3.47) were higher in G1 > 20 than in G2 < 20. After the TAP, TSF, TL and TS returned to baseline values for both groups, with an increase in performance standards and normalization in hormone levels. We suggest that a TSF greater than or equal to 20 could be considered as a fatigue threshold generating hormone disturbance and performance decrement, making it a potentially useful preventive and complementary training monitoring tool.

Heating Up to Keep Cool: Benefits and Persistence of a Practical Heat Acclimation Protocol in Elite Female Olympic Team-Sport Athletes.

PURPOSE: Although recommendations for effective heat acclimation (HA) strategies for many circumstances exist, best-practice HA protocols specific to elite female team-sport athletes are yet to be established. Therefore, the authors aimed to investigate the effectiveness and retention of a passive HA protocol integrated in a female Olympic rugby sevens team training program. METHODS: Twelve elite female rugby sevens athletes undertook 10 days of passive HA across 2 training weeks. Tympanic temperature (TTymp), sweat loss, heart rate, and repeated 6-second cycling sprint performance were assessed using a sport-specific heat stress test Pre-HA, after 3 days (Mid-HA), after 10 days (Post-HA), and 15 days post-HA (Decay). RESULTS: Compared with Pre-HA, submaximal TTymp was lower Mid-HA and Post-HA (both by -0.2 [0.7] °C; d ≥ 0.71), while resting TTymp was lower Post-HA (by -0.3 [0.2] °C; d = 0.81). There were no differences in TTymp at Decay compared with Pre-HA, nor were there any differences in heart rate or sweat loss at any time points. Mean peak 6-second power output improved Mid-HA and Post-HA (76 [36] W; 75 [34] W, respectively; d ≥ 0.45) compared with Pre-HA. The observed performance improvement persisted at Decay by 65 (45) W (d = 0.41). CONCLUSIONS: Ten days of passive HA can elicit some thermoregulatory and performance benefits when integrated into a training program in elite female team-sport athletes. However, such a protocol does not provide a sufficient thermal impulse for thermoregulatory adaptations to be retained after 15 days with no further heat stimulus.

A 6-year retrospective review of injuries sustained during the Singapore Cricket Club International Rugby Sevens tournament.

There are limited studies looking at injury statistics for Rugby Sevens. This study aims to assess injury patterns among amateur players participating in the annual Singapore Cricket Club Rugby Sevens International tournament from 2012 to 2017, by performing a retrospective review of their injury data. Outcome measures include injury incidence rate, injury site, and comparative injury incidence between successive days of competition. A total of 343 injuries were recorded over 6 tournaments, with an injury incidence of 348.0 per 1000 player hours. The lower limb was the most commonly injured site (45.8%), and there was greater incidence of injuries on day 3 of competition compared to day 1 in 2013 and 2016. This study reports a higher level of background risk to Rugby Sevens than is reported in literature. A well designed-prospective injury surveillance study will be necessary to confirm these findings and to investigate risk factors to guide injury prevention programmes.

Asymmetries during repeated treadmill sprints in elite female Rugby Sevens players.

This study describes asymmetry in the main running mechanical variables during repeated treadmill sprints in elite female athletes and examines whether inter-limb differences in sprinting mechanics increase with fatigue. Eighteen elite female players (French national Rugby Sevens team) performed 8 × 5-s sprints (25-s rest) on an instrumented motorised sprint treadmill. The group mean 'symmetry angle' (SA) scores were ~1-2% for contact time (1.6 ± 0.6%), aerial time (2.1 ± 0.8%), step frequency (1.3 ± 0.5%) and step length (1.6 ± 0.6%). Mean vertical and horizontal forces, vertical and leg stiffness presented SA values of 1.7 ± 1.5%, 2.4 ± 1.2%, 2.6 ± 0.2% and 2.5 ± 0.2%, respectively. The SA scores were ~2-8% for duration of braking (6.9 ± 5.0%) and propulsive (6.5 ± 4.4%) phases, peak braking (6.5 ± 2.5%) and propulsive (1.6 ± 0.9%) forces as well as net (5.8 ± 5.6%), braking (7.7 ± 5.3%) and propulsive (2.7 ± 1.6%) impulses. However, there was no influence of sprint repetition number on SA scores for tested variables (P > 0.05). In elite female Rugby Sevens players, there was no noticeable difference in asymmetries for the great majority of stride mechanical variables during repeated treadmill sprints.

Match-play movement demands of international and domestic women's rugby sevens players in an elite dual-level tournament.

OBJECTIVES: To characterize and compare match-play movement demands via Global Positioning Systems (GPS) between international and domestic women's rugby sevens players performing in a novel elite dual-level tournament, with consideration to position and tournament characteristics. DESIGN: Fifty-four rugby sevens players; twenty-one international(5 speed edges, 8 backs, 8 forwards), and thirty-three domestic(10 speed edges, 11 backs, 12 forwards) wore GPS devices during an elite dual-level tournament covering 2 seasons, with 367 full match-play data files analysed. Internationaland domestic players were distributed evenly between competing teams. METHODS: Match-play movement demands were characterized by distance, speed, and acceleration-based indices from 5 to 10 Hz GPS devices. RESULTS: International players recorded significantly higher high-intensity match-play movement demands compared to domestic players in distance in high and very high-speed zones (P = 0.01, P = 0.03, P = 0.01, P = 0.03), maximal acceleration (P = 0.001), maximal velocity (P < .001), speed exertion (P = 0.01), , and acceleration load density (P = 0.03) . Positional analysis demonstrated forwards displayed the largest significant differences between international and domestic players. . Total and relative match-play movement demands of the dual-leveltournament also showed comparable demands to previous international tournament research . CONCLUSIONS: Results identify key points of difference in match-play movement demands between player levels in women's rugby sevens, and provides important information on the characteristics of playing positions, and of a dual-level tournament of this nature. This will improve the design and implementation of structures from domestic to international level.

Running demands and activity profile of men's rugby sevens: a tournament scenario.

This study profiled the changes in running performances and collisions within a Rugby sevens tournament. Sixteen male players were equipped with global positioning system units while competing at the 2015 and 2016 Asia Rugby Sevens series held in Colombo and Hong Kong, respectively. Both tournaments consisted of 4 matches each, and were played over 2 days (i.e., 2 matches/day). Total distance (TD) covered increased in match 3 compared with matches 1 (19 ± 19%; p < 0.001) and 2 (16 ± 11%; p = 0.001), whilst a decrease in TD in match 4 compared with match 3 (8 ± 9%; p = 0.019) was observed. Distances covered within 6.1-12 km·h-1 and 12.1-14 km·h-1 speed bands were generally higher in matches 3 and/or 4 when compared with match 1 and/or 2 (p < 0.05). Frequency of entries into 14.1-18 km·h-1 speed zone was decreased in match 4 compared with match 3 (45 ± 41%; p = 0.009), whilst incidences of heavy, very heavy and severe collisions were generally higher in matches 3 or 4 compared with matches 1 or 2 (p < 0.05). In conclusion, while some decrements in the final match were evident, running performance were generally maintained throughout despite the competitive and congested nature of Rugby Sevens tournaments.

Changes in Salivary Levels of Creatine Kinase, Lactate Dehydrogenase, and Aspartate Aminotransferase after Playing Rugby Sevens: The Influence of Gender.

Rugby sevens is characterised by continuous exertion and great physical contact per unit of time, leading to muscle damage. It is important to identify markers that can quantify muscle damage in order to improve recovery strategies. The objective of this study was to evaluate the release dynamics of muscle damage markers creatine kinase (CK), lactate dehydrogenase (LDH), and aspartate aminotransferase (AST) in saliva samples when playing rugby sevens, analysing the influence of gender, during the rugby sevens university championship of Spain. The total sample included 27 athletes, divided into two teams of 14 men and 13 women between 18 and 31 years of age. CK, LDH, and AST were quantified from salivary samples collected from each athlete before and after three rugby sevens matches. The modified Borg scale of perceived exertion was also used after each match. When the results were analysed globally, there were no differences in CK and LDH before and after any match, but AST did show differences after two days of completing all matches. In terms of gender, the three enzymes showed different responses in men and women. Regarding the Borg scale, there were only significant differences between men and women after completing all mataches, with a greater perceived exertion in women. Based on our results, it can be stated that that serial matches of rugby sevens can cause changes of different magnitude in AST, CK and LDH activities in saliva, with AST showing the most significant variations and these changes are more pronounced in men than in women.

Technical determinants of tackle and ruck performance in International Rugby Sevens.

Abstract Rugby Sevens ('Sevens') is one of the fastest growing sports in the world. This growth was marked by the inclusion of the sport in the Olympic Games in 2016. The most frequently occurring contact events in Sevens are the tackle and ruck. Performing specific techniques during these contact events can reduce the risk of injury and increase the likelihood of success. Therefore, the purpose of this study was to identify the technical determinants associated with tackle and ruck performance outcomes in Sevens. A total of 4799 tackles and 1405 rucks from the 2014/2015 HSBC Sevens World Series were coded for contact, post-contact, ruck, match contextual variables and outcomes. Relative risk ratio (RR), the ratio of the probability of an outcome occurring when a variable was observed, was determined using multinomial logistic regression. A moderate ball-carrier leg drive reduced the probability of losing possession by 25% (RR 0.75, 95% CI, 0.58-0.97, p < .05). Conversely, ball-carriers had a 53% higher likelihood of losing possession when the tackler executed a moderate leg drive (RR 1.53, 95% CI, 1.09-2.14, p ≤ .05). Maintaining possession at the ruck was more likely to occur when committing one attacker compared to two (RR 0.31, 95% CI, 0.19-0.49, p < .001). Active ball-carrier placement also increased the likelihood of maintaining possession at the ruck (RR 14.67, 95% CI, 9.55-22.56, p < .001). Sevens coaches and trainers can now positively design evidence-based technical training programmes and emphasise specific tackle techniques in training using data from Sevens video analysis. Also, given that this is the first study to relate tackle technical determinants to an outcome (i.e. the first 'how' study) in Sevens, this work provides the foundation for similar Sevens video analysis studies in the future.

Psychological Demands of International Rugby Sevens and Well-Being Needs of Elite South African Players.

Rugby sevens was included in the 2016 Olympic Games, with South Africa's Blitzboks winning bronze. They also won the 2016/2017 and 2017/2018 World Rugby Sevens Series. Whilst peak performance is paramount at the elite level there is a growing responsibility to address player well-being and off-the-field player needs. This study explored the psychological demands of international rugby sevens and the well-being needs of elite players. Twenty professional players (age range: 21-33 years) participated in semi-structured interviews. Qualitative content analysis yielded five categories of psychological demands: (1) tournament structure, (2) resilience, (3) cope with physicality, (4) perform when fatigued, and (5) perform under pressure. The prevailing team culture included: (1) team cohesion, (2) clear purpose, (3) work ethic, (4) team values, (5) happy environment, (6) relationships with coaching staff, and (7) faith. Various psychological skills [(1) goal-directed behavior, (2) compartmentalization, (3) deal with anxiety, (4) motivation, (5) imagery, and (6) self-confidence] and mental strategies [(1) coping, (2) "back-to-zero," (3) creativity, and (4) cognitive triggers] utilized by the players are discussed. Their general well-being and individual needs were: (1) physical needs, (2) financial concerns/needs, (3) preparation for life after rugby career, (4) support structures, and (5) mental (ill) health. This information could be useful to develop an integrated sport psychological and well-being program aimed at improving performance and facilitating psychological well-being both during and after retirement from elite sport.

Can we use GPS for assessing sprinting performance in rugby sevens? A concurrent validity and between-device reliability study.

The purpose of this study was to (1) provide data on maximal sprinting speed (MSS) and maximal acceleration (Amax) in elite rugby sevens players measured with GPS devices, (2) test the concurrent validity of the signal derived from a radar device and a commercially available 16 Hz GPS device, and (2) assess the between-device reliability of MSS and Amax of the same GPS. Fifteen elite rugby sevens players (90 ± 12 kg; 181 ± 8 cm; 26 ± 5 y) participated in the maximal sprinting test. A subset of five players participated in the concurrent validity and between-devices reliability study. A concurrent validity protocol compared the GPS units and a radar device (Stalker ATS II). The between-device reliability of the GPS signal during maximal sprint running was also assessed using 6 V2 GPS units (Sensorevery-where, Digital Simulation, Paris, France) attached to a custom-made steel sled and pushed by the five athletes who performed a combined total of 15 linear 40m sprints. CV ranged from 0.5, ±0.1 % for MSS and smoothed MSS to 6.4, ±1.1 % for Amax. TEM was trivial for MSS and smoothed MSS (0.09, ±0.01) and small for Amax and smoothed Amax (0.54, ±0.09 and 0.39, ±0.06 respectively). Mean bias ranged from -1.6, ±1.0 % to -3.0, ±1.1 % for smoothed MSS and MSS respectively. TEE were small (2.0, ±0.55 to 1.6, ±0.4 %, for MSS and smoothed MSS respectively. The main results indicate that the GPS units were highly reliable for assessing MSS and provided acceptable signal to noise ratio for measuring Amax, especially when a smoothing 0.5-s moving average is used. This 16 Hz GPS device provides sport scientists and coaches with an accurate and reliable means to monitor running performance in elite rugby sevens.

Perfil antropométrico e imagen corporal de escolares rugbistas de sexo femenino de la Región de la Araucanía, Chile / Perfil antropométrico e imagem corporal de escolares do sexo feminino jogadoras de rugby da região de araucanía, chile / Anthropometric profile and body image of female junior rugby players from the region of araucanía, chile

Resumen Lagos-Hernández, R.I. et al. (2018). Perfil antropométrico e imagen corporal de escolares rugbistas de sexo femenino de la región de la Araucanía, Chile. PENSAR EN MOVIMIENTO: Revista de Ciencias del Ejercicio y la Salud, 16(2), 1-15. El objetivo de esta investigación fue determinar perfil antropométrico y su relación con el IMC e imagen corporal (IC) del total de escolares de sexo femenino de la Región de la Araucanía, Chile, que practican regular y competitivamente rugby 7. En relación a las participantes, se evaluaron 25 niñas que reunían los criterios de inclusión cuyas edades fluctuaron entre los 10 y 19 años (Media = 16.39 ± 2.81). Para efectos metodológicos se llevó a cabo una evaluación Antropométrica bajo los protocolos de la International Society for the Advancement of Kinanthropometry protocols (ISAK , 2017) y se hizo una apreciación de la percepción de la IC a través de la observación de una serie de imágenes corporales siguiendo el protocolo de Montero, Morales, & Carbajal (2004). Los resultados mostraron que las escolares evaluadas presentan una composición corporal (CC) alta en tejido adiposo con un 33.9% y un porcentaje muscular de 39%. En relación a la clasificación antropomética, se puede señalar que manifiestan características endo-mesomorficas, además se pudo constatar que las escolares presentaron una percepción de la IC según IMC percibido, diferente de los niveles reales de IMC presentados, no apreciándose relacion estadísticamente significativa entre la CC, el somatotipo y la imagen percibida.

Abstract Lagos-Hernández, R.I. et al. (2018). Anthropometric profile and body image of female junior Rugby players from the Region of Araucanía, Chile. PENSAR EN MOVIMIENTO: Revista de Ciencias del Ejercicio y la Salud, 16(2), 1-15. The objective of this paper was to determine the anthropometric profile of female students of the Region of Araucanía, Chile, and its relationship with BMI (IMCA) and body image (IC). Participants included 25 girls ages 10 to 19 (mean = 16.39 ± 2.81) that practice rugby sevens on a regular and competitive basis. For methodological purposes, an anthropometric assessment was conducted using the International Society for the Advancement of Kinanthropometry protocols (ISAK, 2017), and an appreciation of CI perception was made by observing a series of body images following the Montero, Morales, & Carbajal protocol (2004). Results showed that the students' body composition (CC) was high in adipose tissue (33.9%) and their muscle percentage was 39%. Regarding the anthropometric classification, it can be noted that participants show endo-mesomorph characteristics and that their perceived body image differed from the actual BMI levels, not showing a statistically significant relationship between the body composition, the somatotype and the perceived image.

Resumo Lagos-Hernández, R.I. et al. (2018). Perfil antropométrico e imagem corporal de escolares do sexo feminino jogadoras de rugby da região de Araucanía, Chile. PENSAR EN MOVIMIENTO: Revista de Ciencias del Ejercicio y la Salud, 16(2), 1-15. O objetivo desta pesquisa foi determinar o perfil antropométrico e sua relação com o IMC e a imagem corporal (IC) de todas as escolares da região de Araucania, Chile, que praticam regularmente o rugby 7 em carácter competitivo. Em relação aos participantes, foram avaliadas 25 meninas que atendiam aos critérios de inclusão cujas idades variaram entre 10 e 19 anos (média = 16,39 ± 2,81). Para fins metodológicos, foi levada a cabo uma avaliação antropométrica sob os protocolos da Society for Avancement in Kineanthropometric (ISAK, 2017) e feita uma apreciação da percepção do IC através da observação de uma série de imagens corporais seguindo o protocolo de Montero, Morales e Carbajal (2004). Os resultados mostraram que as estudantes avaliadas apresentam uma composição corporal (CC) elevada no tecido adiposo com 33,9% e um percentual muscular de 39%. Quanto à classificação antropométrica, pode-se destacar que se manifestam características endo-mesomórficas e, além disso, verificou-se que as escolares apresentaram uma percepção de IC de acordo com o IMC percebido, diferente dos níveis reais de IMC apresentados, não sendo apreciada uma relação estatisticamente significativa entre a CC, o somatótipo e a imagem percebida.

Lower-Limb Passive Heat Maintenance Combined With Pre-cooling Improves Repeated Sprint Ability.

Pre-conditioning strategies to potentiate performance are a common feature of pre-competition routines. The elevation of muscle temperature is seen as a vital component of preparing for physical performance, while pre-cooling strategies have been adopted to offset fatigue during repeated efforts. We investigated the individual and combined effects of a passive heat maintenance strategy and the ingestion of an ice-water slurry on repeated sprint performance. In a random cross-over design, 12 professional male athletes performed 5 × 40 m maximal running sprints under one of four conditions following a standardized warm-up: 15-min passive rest (Control); wearing a lower-body survival garment (HEAT); consuming a 500 mL ice slushy (COLD); or wearing the survival garment and consuming the slushy (H+C). Measures of sprint speed, fatigue, heart rate, and rectal temperature were collected. Compared to COLD: HEAT improved Sprint 1 (ES: 0.84; p = 0.05), but negatively impacted Sprint 4 (ES: -0.87; p = 0.08), and Sprint 5 (ES: -1.57; p = 0.002). H+C was faster than Control for every sprint (ES: 0.28 to 0.66), clearly faster than COLD on Sprints 1-3 (ES: 0.73 to 0.54), and clearly faster than HEAT on Sprints 4 and 5 (ES: 1.31 and 1.87). Fatigue was greatest after the HEAT intervention with a large correlation between fatigue and rectal temperature (r = 0.66; p = 0.0204). While there are undoubtedly peripheral effects of cooling and heating on various aspects of muscle function and fatigue, understanding the integration of psychophysiological homeostatic feedback loops relating to a combined warming and cooling intervention may benefit sports in which repeat sprints are performed.

Epidemiology of injuries in Portuguese senior male rugby union sevens: a cohort prospective study.

OBJECTIVES: To assess the incidence, type and location of injuries sustained during the Portuguese rugby union sevens circuit. To investigate the influence of players' training loads on injury risk. METHODS: A prospective cohort study recording time-loss injuries was conducted with all teams competing in the Portuguese national rugby sevens circuit (eight from the top-tier and seven from the second-tier). Main outcome measures included: incidence rate, anatomical location, type, injury incident and severity. Data were also collected regarding players' training loads. Fisher's exact test was used to estimate the relative risk of suffering an injury during the sevens season and training sevens during the fifteens season. RESULTS: A total of 27 injuries were recorded corresponding to an incidence rate of 133.9 injuries per 1000 player match-hours. The average severity was 22.22 days. Contact events preceded 81.5% of injuries. Most injuries occurred in the lower limb (66.7%) and were joint/ligament or muscle/tendon injuries (85.1%). The association between injuries and lower volume of training during the sevens season was identified for the second-tier (p = 0.021). For the same level, an inverse relation between training hours and injury severity was also found (p = 0.008). Top-tier players training sevens and fifteens simultaneously during the year presented a significant increase of injury risk (relative risk = 3.2; p = 0.011). CONCLUSIONS: Injury incidence in our study is similar to that reported for international sevens, although severity is lower. An association between training loads and the occurrence of injuries was found for both tiers, although with differential results, thus reinforcing the need to customize players' preparation. Further studies at non-elite competitions are needed to gather significant data to accurately formulate future injury prevention protocols or recommend modifications to game laws or competition formats, aiming at players' welfare.

Modelling injury-burden in rugby sevens.

OBJECTIVES: To develop a time-based model of injury-burden for international rugby sevens teams and to demonstrate its utility. DESIGN: Descriptive, cohort study. METHODS: Injury data recorded during seven seasons of the Sevens World Series were used to quantify the rate of injury and the rate at which injured players recovered from injury. An equation describing the rate at which injuries were sustained was combined with an equation for the rate at which injured players recovered from injury to produce a time-based equation for the injury-burden of rugby sevens players at any point in time during a season. RESULTS: The overall rates at which match and training injuries were sustained (incidence of injury) were 108.6 (95% confidence interval: 101.6-116.1) injuries/1000 player-match-hours and 0.91 (95% CI: 0.65-1.27) injuries/1000 player-training-hours, respectively. Injured players recovered from injury according to a first-order rate equation with a rate constant of 0.0257 days-1 calculated from the median severity of injuries sustained (27 days). The time-based injury-burden values predicted from the proposed kinetic model of injury-burden closely matched the values recorded in the Sevens World Series. CONCLUSIONS: For governing bodies in rugby, the proposed model provides a way to examine the consequences of changes in the number and timing of international rugby sevens tournaments. For individual teams, the model provides a means to forecast and manage the team's injury-burden as a function of the team's scheduled match and training loads throughout a season.

Supercompensation Kinetics of Physical Qualities During a Taper in Team-Sport Athletes.

Peaking for major competition is considered critical for maximizing team-sport performance. However, there is little scientific information available to guide coaches in prescribing efficient tapering strategies for team-sport players. PURPOSE: To monitor the changes in physical performance in elite team-sport players during a 3-wk taper after a preseason training camp. METHODS: Ten male international rugby sevens players were tested before (Pre) and after (Post) a 4-wk preseason training camp focusing on high-intensity training and strength training with moderate loads and once each week during a subsequent 3-wk taper. During each testing session, midthigh-pull maximal strength, sprint-acceleration mechanical outputs, and performance, as well as repeated-sprint ability (RSA), were assessed. RESULTS: At Post, no single peak performance was observed for maximal lower-limb force output and sprint performance, while RSA peaked for only 1 athlete. During the taper, 30-m-sprint time decreased almost certainly (-3.1% ± 0.9%, large), while maximal lower-limb strength and RSA, respectively, improved very likely (+7.7% ± 5.3%, small) and almost certainly (+9.0% ± 2.6%, moderate). Of the peak performances, 70%, 80%, and 80% occurred within the first 2 wk of taper for RSA, maximal force output, and sprint performance, respectively. CONCLUSIONS: These results show the sensitivity of physical qualities to tapering in rugby sevens players and suggest that an ~1- to 2-wk tapering time frame appears optimal to maximize the overall physical-performance response.

Epidemiology of injuries in senior male rugby union sevens: a systematic review.

OBJECTIVES: In 2016 the Rugby Union variant of sevens will enter the official Olympic Programme. Until now, most of injury surveillance studies in Rugby Union focus on elite 15-a-side cohorts, with reported injury incidence rates reaching 96 per 1000 player-match-hours, and mean severity set at 20 days. Sparse data is available regarding rugby sevens. The aim of this study was to systematically review available data regarding the epidemiology of injuries in senior male rugby sevens. METHODS: Electronic databases (Pubmed, Google Scholar, SCOPUS, Scielo and IndexRMP) were searched in September 2015, complemented by manual searches of bibliographies and relevant "grey literature". RESULTS: Seven prospective cohort original articles addressing injuries in senior male rugby sevens players were included in this review. Overall injury incidence rates in elite rugby sevens tournaments ranged 101.5 to 119.8 per 1000 player-match-hours. Mean severity was greater than 34.1 days. Lower limb and joint/ligament injuries were the most frequent in elite players. The only study on amateur players revealed a lower injury incidence rate (74.7 per 1000 player-match-hours), and a higher proportion of muscle/tendon (37.5 %) injuries. CONCLUSION: Injury incidence rates in rugby sevens are higher than those reported for the 15-a-side variant, at the same level of competition. Injuries are also more severe, resulting in longer absence periods. This might result from the fact that rugby sevens is played with greater speed, leading to an increase in energy transfers during tackles, more running and turning manoeuvers, that can possibly cause more severe injuries.

Multifactorial monitoring of training load in elite rugby sevens players: cortisol/cortisone ratio as a valid tool of training load monitoring.

The effectiveness of selected physiological and perceptual measures for monitoring training load and fatigue was studied in 16 male elite rugby sevens players during a 6-week intense training block (IT) and 2-week tapering (TAP). Daily training load (TL) and strain (TS) as well as weekly total score of fatigue (TSF) were quantified respectively by the session-rating of perceived exertion (RPE) method and an 8-item questionnaire. Also, testing was performed and 24 h urinary cortisol (C), cortisone (Cn), adrenaline (A) and noradrenalin (NA) excretion was measured before (T0) and after the IT (T1) and after the TAP (T2). The TL, TS and TSF increased during the IT and decreased during the TAP, in conjunction with a significant drop and improvement, respectively, of performance standards during the two periods. At T1, C and Cn levels increased while A and NA levels decreased, resulting in a higher C/Cn ratio and lower A/NA ratio, respectively. At T2, both C/Cn and A/NA returned to baseline values. The changes in C/Cn ratio, after the 6-week IT, were more closely related to mean TL, TS and TSF (r=0.75-0.76 vs. r=0.48-0.58, p<0.01) and to changes in the majority of performance measures than to A/NA ratio. Only the changes in C/Cn ratio after the 2-week TAP were related to mean TL, TS and TSF (r=0.61-0.68, p<0.01). The changes in hormone levels, training strain and performance standards reflected the physical and mental stressors of training, with complete recovery, as indicated by physiological homeostasis, achieved after an appropriate tapering period.