Repeated High-Intensity Effort Activity in International Male Rugby Sevens.

ABSTRACT: Couderc, A, Gabbett, TJ, Piscione, J, Robineau, J, Peeters, A, Igarza, G, Thomas, C, Hanon, C, and Lacome, M. Repeated high-intensity effort activity in international male Rugby Sevens. J Strength Cond Res 35(6): 1720-1726, 2023-Rugby Sevens is characterized by repeated high-intensity accelerations, sprinting, and collisions, commonly referred to as repeated high-intensity effort (RHIE) activity. Although repeated acceleration and sprinting activity of Rugby Sevens has been investigated, to date, no study has investigated the repeated running and collision activity of international Rugby Sevens during competitive events. In this study, 15 elite players competed in 44 matches during the HSBC World Sevens Series. Global positioning systems and match analysis software were used to quantify the frequency of repeated running and collision efforts. High acceleration (≥2.5 m·s -2 ), high speed (above maximal aerobic speed), sprint (above 85% of maximal sprint speed), and collision efforts (tackles, ruck, and contact) were considered as high-intensity effort activities. An RHIE bout was defined as 3 or more high-intensity efforts with less than 21 seconds recovery between efforts. The difference between positional groups (forward and backs) and first and second halves was compared using magnitude-based inferential statistics. One hundred twelve individual match observations were analyzed. On average, players performed 27 high-intensity effort events across the game. The distribution of high-intensity efforts included the following: 37% collisions, 34% accelerations, 27.5% high-velocity running, and 1.5% sprints. An average of 3.7 RHIE bouts was performed per player. The difference in high-intensity efforts and number of RHIE bouts performed were trivial/small when compared between first and second halves, and between forward and back positional groups. Repeated high-intensity effort bouts play an important role in the activity profile of elite Rugby Sevens players. This study could provide a framework for performance analysts and coaches to analyze match-related performance of elite Rugby Sevens players, taking into account both the high-intensity running and collision components of the game. Coaches should implement training interventions to ensure the maintenance of RHIE performance during competitive events.

A comparison of running and contact loads in U18 and U20 international rugby union competition.

The purpose of the present study was to characterize and compare locomotor and contact loads in U18 and U20 international rugby union competition during matches, and specifically during peak match-play phases using short rolling epochs and continuous ball-in-play (BIP) sequences. 20 international matches from French national teams were analysed in the U18 and U20 Six Nations Tournament respectively and World Rugby U20 Championship. Running loads were quantified using global positioning devices (16 Hz) and contact loads via video match analysis software. Players were split into forward (U18, n = 29; U20, n = 32) and back positional groups (U18, n = 20; U20, n = 24). Compared with U20 peers, U18 players covered a higher total distance (effect size (ES) = -0.76 ± 0.25) and at high-speeds per minute (> 4 m · s-1; ES = -0.55 ± 0.25) and performed more accelerations (ES = -0.71 ± 0.25). While a greater frequency of BIP sequences > 90 s duration was observed in U20s versus U18s match-play, U18s covered more total distance and high-speed distance (ES = -0.42 ± 0.13 and -0.33 ± 0.13 respectively) per minute during these longer sequences. During peak rolling phases shorter than 4 minutes, no clear differences existed between age categories in running activity, while U20 forwards performed more contact actions than U18 peers. The match-play loads observed in the present international U18 players suggest that they are ready to respond to the overall and peak demands observed in U20 competition. Moreover, the present information on peak activity phases can aid design of overload high-intensity conditioning sessions to respond to the running- and contact-demands identified in those competitions.

A multi-nation examination of the fatigue and recovery time course during the inaugural Under-18 Six Nations rugby union competition.

The purpose of this study was to investigate the neuromuscular and perceptual fatigue responses of elite rugby players during the inaugural Under-18 (U18) Six Nations Festival. One hundred and thirty-three male players from five national squads (73 forwards, 60 backs) were examined during the competition. Each national squad was involved in three matches separated by 96 h each. Over the competition, players completed a daily questionnaire to monitor perceived well-being (WB) and performed daily countermovement jumps (CMJ) to assess neuromuscular function (NMF). Reductions in WB were substantial 24 h after the first and second match in forwards (d=0.77±0.21, p<0.0001; d=0.84±0.22, p< 0.001) and backs (d=0.89±0.22, p <0.0001; d=0.58±0.23, p<0.0001) but reached complete recovery in time for the subsequent match. Reductions in CMJ height were substantial 24 h after the first and second match for forwards (d=0.31±0.15, p=0.001; d=0.25±0.17, p=0.0205) and backs (d=0.40±0.17, p=0.0001; d=0.28±0.17, p=0.0062) and recovered at 48 h after match-play. Average WB and CMJ height attained complete recovery within matchday cycles in the investigated international competition. The findings of this study can be useful for practitioners and governing bodies involved with fixture scheduling and training prescription during competitive periods.

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.

In-Match Physical Performance Fluctuations in International Rugby Sevens Competition.

It is widely recognised that the physical demands in rugby sevens are high especially in comparison to the 15-aside version. The aim of this study was to assess fluctuations in physical performance (running and contact loads) in international rugby sevens competition. Altogether, 32 matches played by an international team in the HSBC World Sevens Series were analyzed (63 match-observations). Players wore a validated GPS device (SensorEverywhere, France) sampling at 16Hz while an operator coded every contact action (tackles, collisions, mauls, scrums) using video analysis software (SportsCode, USA). Running load was assessed using total distance travelled (m), individually determined high-speed distance (covered at velocities > maximal aerobic speed, m) and very-high speed distance (covered at velocities > 85% maximal sprinting speed, m). The frequency of accelerations (actions > 2.5 m·s-2) and high-intensity actions (HIA, sum of high-velocity runs, accelerations and contact-related actions, n) were also calculated. A magnitude-based inferential approach to statistics was adopted and effect sizes quantified. Findings showed: 1) a small decrease in high-speed distance and number of accelerations performed during the second- versus the first-half of play suggesting a decline in running performance. (2) a moderately higher total distance and high-speed distance covered during the first and final 1-min period compared to the average for other 1-min periods, suggesting a specific reverse 'J-shape' pacing profile 3) a most likely decrease in total distance, high-speed running, and to a lesser extent the number of accelerations declined following the peak 1-min period of the game. These findings provide pertinent information on changes in running performance over the course of international sevens and have implications for physical conditioning strategies.

Anthropometric and physical characteristics in U16, U18 and U20 elite French youth rugby union players.

The aims of this study in elite youth French players were to 1) describe the anthropometric and physical characteristics of international and non-international players from U16 to U20, and 2) compare these characteristics across age categories and playing standard (international or non-international). Altogether, 1423 players from the French Rugby Federation's academies participated in a physical testing battery, part of its national young player development pathway. From seasons 2010 to 2020, players were assessed for anthropometric (body mass and height), off-field (bench press; isometric squat, vertical jump) and on-field physical characteristics (aerobic capacity: maximal aerobic speed [MAS]; speed: 10-m, 50-m sprint). A 2-way mixed model analysis of variance (ANOVA) was used to compare physical characteristics across age categories and playing standards. Two separate models were used for forwards and backs. A main statistical effect was observed for age category and playing standard (range p < 0.05 -p < 0.001). Pair-wise category comparisons showed that older players were generally taller, heavier, stronger, faster and demonstrated better aerobic qualities than younger peers. The same results were observed for INT compared with NI players while INT forwards were also taller and heavier than NI peers (range p < 0.01 -p < 0.001). Findings revealed a clear progression in anthropometric characteristics and physical qualities throughout the age development pathway in elite young French rugby players. Findings also identified certain physical qualities (strength, power and speed) necessary at younger levels to achieve international standard.

Concurrent Validity and Reliability of Sprinting Force-Velocity Profile Assessed With GPS Devices in Elite Athletes.

PURPOSE: The aims of this study were to (1) assess the concurrent validity of global positioning systems (GPSs) against a radar device to measure sprinting force-velocity (F-v) profiles and (2) evaluate the interunit reliability of 10-Hz GPS devices (Vector S7, Catapult Innovations). METHODS: Sixteen male elite U18 rugby union players (178.3 [7.6] cm; 78.3 [13.2] kg) participated. Two 50-m sprints interspersed with at least 5 minutes of recovery were completed to obtain input (maximal sprint speed and acceleration time constant τ) and output (theoretical maximal horizontal force, sprinting speed, and horizontal power) F-v profile variables. Sprint running speed was concurrently measured with a radar and 2 GPS units placed on the upper back of each player. Concurrent validity and interunit reliability analyses were performed. RESULTS: Moderate to nearly perfect correlations were observed between radar and GPS-derived F-v variables, with small to large typical errors. Trivial to small coefficients of variation were found regarding the GPS interunit reliability. CONCLUSION: The GPS devices tested in this study represent a valid and reliable alternative to a radar device when assessing sprint acceleration F-v profiles in team-sport players.

Does perceived wellness influence technical-tactical match performance? A study in youth international rugby using partial least squares correlation analysis.

The purpose of this study was to determine the relationship between matchday wellness status and a technical-tactical performance construct during rugby match-play. One hundred and thirty-three male rugby union players (73 forwards and 60 backs) from five under-18 national squads who participated in the under-18 Six Nations competition completed a subjective wellness questionnaire on each matchday morning. Players subjectively rated each item (sleep quality, fatigue, muscle soreness, stress and mood) on a five-point Likert scale to calculate their daily wellness status (i.e. difference between matchday and baseline perceived wellness). Technical-tactical performance during match-play was quantified by coding individual key performance indicators (e.g. number of carries, number of tackles). Partial least squares correlation analysis (PLSCA) was employed to compute the latent variables of perceived wellness status (X matrix) and technical-tactical performance (Y matrix) for each player observation (n = 271). The latent variables are a construct of each variable group, enabling higher dimensional data to be visualised more simply. Linear mixed-effect models were later conducted to assess the relationships between the latent variables. The effect of perceived wellness status on technical-tactical performance was statistically significant in forwards (p = .042), not statistically significant in backs (p = .120) and accounted for 4.9% and 1.9% variance in the technical-tactical performance construct, respectively. The findings of this study suggest that perceived wellness status can influence technical-tactical match performance, but the practical significance of these findings should be interpreted with caution given the amount of variance in technical-tactical performance accounted by the models.

"Road to Rio": A Case Study of Workload Periodization Strategy in Rugby-7s During an Olympic Season.

The objective of this manuscript was to examine the periodization strategy of an international Rugby-7s team during an Olympic season. Training load data were collected in 14 elite male players over a 48-week period during the 2015-2016 Olympic season. The season consisted of 3 macrocycles including: preseason (12-weak duration), in-season (25-weak) fragmented into four 4-7 weeks mesocycles (In-1-4) and the final preparation for the Rio 2016 Olympic Games (Olympic preparation, 11-weak). External training load (TL) such as the total distance (TD), the high-intensity distance (HID) and the number of accelerations performed, was monitored in training and competition over the entire duration of the season using a global positioning system (GPS) devices. The rating of perceived exertion (RPE) was multiplied by the session duration (min) to provide an internal TL (session-RPE) value for all training sessions and competitions. The Olympic preparation may enable planning of higher external TL compared to the preseason (TD, 21 ± 13%, moderate; total accelerations, 27 ± 4%, moderate) whereas no difference was observed for internal TL values between these two periods. High-intensity distance (HID) and internal TL (session-RPE) were lower (-11.0 ± 7.8%, small and -38 ± 3%, moderate, respectively) during the in-season compared to preseason. Internal TL, TD as well as HID were lower in the third in-season mesocycle (In-3) compared with the first in-season mesocycle (In-1) (-25 ± 12%, moderate; -32 ± 4%, moderate; -49 ± 8%, moderate, respectively). The staff managed the workload considering the in-season as the main part of the "Road to Rio." The strategy to reduce the workload at the middle of the season and to induce weeks of regeneration at the end of the in-season was highlighted by the training availability of 100% of the squad at the beginning of the Olympic preparation. The workload periodization strategy of an Olympic season differs from the strategy previously described during a non-Olympic season.

Preconditioning Strategy in Rugby-7s Players: Beneficial or Detrimental?

PURPOSE: Preconditioning strategies are considered as opportunities to optimize performance on competition day. While investigations conducted in rugby players on the effects of a morning preconditioning session already exist, additional work is warranted. The aim of this study was to monitor changes in physical and psychophysiological indicators among international Rugby-7s players following a priming exercise. METHODS: In a randomized crossover-design, fourteen under-18 international Rugby-7s players completed, at 8:00am, a preconditioning session consisting of a warm-up followed by small-sided games, accelerations and 2 x 50-m maximal sprints (Experimental) or no pre-loading session (Control). Following a 2-hour break, the players performed a set of six 30-m sprints and a Rugby-7s match. Recovery-stress state and salivary stress-markers levels were assessed before the preloading session (Pre), immediately after (Post-1), before the testing session (Post-2) and after (Post-3). RESULTS: Experimental-Control differences in performance across a repeated sprint test consisting of six 30-m sprints were very likely trivial (+0.2 ±0.7%, 3/97/1%). During the match, the total distance covered and the frequency of decelerations were possibly lower (small) in Experimental compared to Control. Differences observed in the other parameters were unclear or possibly trivial. At Post-2, the perceived recovery-stress state was improved (small difference) in Experimental compared with Control. No difference in salivary cortisol response was observed while the preconditioning session induced a higher stimulation of salivary testosterone and alpha-amylase. CONCLUSIONS: The players' ability to repeat sprints and physical activity in match-play did not improve but their psychophysiological state was positively affected after the present pre-conditioning session.

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.