Simon P. Roberts

The physical demands of elite English rugby union

Abstract The aim of this study was to assess the physical demands of elite English rugby union match-play. Player movements were captured by five distributed video cameras and then reconstructed on a two-dimensional plane representing the pitch. Movements based on speeds were categorized as standing, walking, jogging, and medium-intensity running (low-intensity activity), and high-intensity running, sprinting, and static exertion (scrummaging, rucking, mauling, and tackling) (high-intensity activity). Position groups were defined as forwards (tight and loose) and backs (inside and outside). Backs travelled more total distance than forwards (6127 m, s = 724 vs. 5581 m, s = 692; P < 0.05) and greater distances in walking (2351 m, s = 287 vs. 1928 m, s = 2342; P < 0.001) and high-intensity running (448 m, s = 149 vs. 298 m, s = 107; P < 0.05). Forwards performed more high-intensity activity than backs (9:09 min:s, s = 1:39 vs. 3:04 min:s, s = 1:01; P < 0.001), which was attributable to more time spent in static exertion (7:56 min:s, s = 1:56 vs. 1:18 min:s, s = 0:30; P < 0.001), although backs spent more time in high-intensity running (0:52 min:s, s = 0:19 vs. 1:19 min:s, s = 0:26; P = 0.004). Players travelled a greater distance in the first 10 min compared with 50–60 and 70–80 min, but there was no difference in the amount of high-intensity activity performed during consecutive 10-min periods during match-play. These results show the differing physical demands between forwards and backs with no evident deterioration in high-intensity activity performed during match-play.

Effects of carbohydrate and caffeine ingestion on performance during a rugby union simulation protocol.

Abstract In this study, we investigated the effect of ingesting carbohydrate alone or with caffeine on performance of a rugby union-specific shuttle running protocol. On three occasions, at least one week apart in a counterbalanced trial order, eight male rugby union forwards ingested either placebo or carbohydrate (1.2 g · kg−1 body mass · h−1) before and during a rugby union-specific protocol, with pre-exercise caffeine ingestion (4 mg · kg−1) before one of the carbohydrate trials (carbohydrate + caffeine). The intermittent exercise protocol included walking, jogging, and cruising at pre-determined intensities, simulated contact events, a sustained high-intensity test of speed and agility (Performance Test), and a 15-m sprint. Ratings of perceived exertion (RPE) were recorded every 5 min and a motor skills test was performed after each 21-min block. Performance Test times were not significantly different between trials but the likelihood of 2% improvements for carbohydrate + caffeine over placebo and carbohydrate were 98% and 44%, respectively. For carbohydrate + caffeine, 15-m sprints were faster than for placebo (P=0.05) and the motor skills test was performed faster in the carbohydrate + caffeine trial than the carbohydrate and placebo trials (P < 0.05), while RPE was lower in the carbohydrate + caffeine trial than the carbohydrate and placebo trials (P < 0.05). The results indicate a likely benefit to rugby performance following co-ingestion of carbohydrate and caffeine.

Epidemiology of time-loss injuries in English community-level rugby union

Objectives Using a prospective cohort study design, to establish the incidence and nature of time-loss injuries in English community rugby and to assess the differences between different playing levels. Setting English community rugby clubs. Participants Injury information for 4635 matches was collected during seasons 2009/2010 (46 clubs), 2010/2011(67 clubs) and 2011/2012 (76 clubs). Clubs were subdivided into groups A (semiprofessional), B (amateur) and C (recreational) for analysis. Primary and secondary outcome measures Any injury resulting in 8 days or greater absence from match play was reported by injury management staff at the clubs. The primary outcome measure was injury incidence (per 1000 player match-hours) and the secondary outcome measure was severity (ie, days absence). Results Overall match injury incidence was 16.9 injuries per 1000 player match-hours. Incidence was higher for group A (21.7; 95% CI 19.8 to 23.6) compared with group B (16.6; 95% CI 15.2 to 17.9) and C (14.2; 95% CI 13.0 to 15.5, both p<0.001). The mean time-loss was 7.6 weeks absence, with knee and shoulder injuries the most severe with mean absences of 11.6 and 9.3 weeks, respectively. Half of all injuries occurred to the lower limb, with knee and ankle joint/ligament injuries the most common diagnoses. Shoulder joint/ligament injuries were the most common and severe upper limb injuries. Contact events accounted for 80% of all injuries and tackles accounted for 50%. Running was the most common non-contact injury event, of which 56% were hamstring injuries. Conclusions More time-loss injuries occur at higher levels of community rugby. Injury prevention strategies should focus on good technique in the tackle and conditioning exercises for the knee, ankle, hamstrings and shoulder.

The Relationship Among Peak Power Output, Lactate Threshold, and Short-Distance Cycling Performance: Effects of Incremental Exercise Test Design

The purpose of this study was to compare the physiological results of 2 incremental graded exercise tests (GXTs) and correlate these results with a short-distance laboratory cycle time trial (TT). Eleven men (age 25 ± 5 years, &OV0312;O2max 62 ± 8 ml·kg−1·min−1) randomly underwent 3 laboratory tests performed on a cycle ergometer. The first 2 tests consisted of a GXT consisting of either 3-minute (GXT3-min) or 5-minute (GXT5-min) workload increments. The third test involved 1 laboratory 30-minute TT. The peak power output, lactate threshold, onset of blood lactate accumulation, and maximum displacement threshold (Dmax) determined from each GXT was not significantly different and in agreement when measured from the GXT3-min or GXT5-min. Furthermore, similar correlation coefficients were found among the results of each GXT and average power output in the 30-minute cycling TT. Hence, the results of either GXT can be used to predict performance or for training prescription.

Collapsed scrums and collision tackles: what is the injury risk?

Aim To establish the propensity for specific contact events to cause injury in rugby union. Methods Medical staff at participating English community-level rugby clubs reported any injury resulting in the absence for one match or more from the day of the injury during the 2009/2010 (n=46), 2010/2011 (n=67) and 2011/2012 (n=76) seasons. Injury severity was defined as the number of matches missed. Thirty community rugby matches were filmed and the number of contact events (tackles, collision tackles, rucks, mauls, lineouts and scrums) recorded. Results Of 370 (95% CI 364 to 378) contact events per match, 141 (137 to 145) were tackles, 115 (111 to 119) were rucks and 32 (30 to 33) were scrums. Tackles resulted in the greatest propensity for injury (2.3 (2.2 to 2.4) injuries/1000 events) and the greatest severity (16 (15 to 17) weeks missed/1000 events). Collision tackles (illegal tackles involving a shoulder charge) had a propensity for injury of 15 (12.4 to 18.3) injuries/1000 events and severity was 92 (75 to 112) weeks missed/1000 events, both of which were higher than any other event. Additional scrum analysis showed that only 5% of all scrums collapsed, but the propensity for injury was four times higher (2.9 (1.5 to 5.4) injuries/1000 events) and the severity was six times greater (22 (12 to 42) weeks missed/1000 events) than for non-collapsed scrums. Conclusions Injury prevention in the tackle should focus on technique with strict enforcement of existing laws for illegal collision tackles. The scrum is a relatively controllable event and further attempts should be made to reduce the frequency of scrum collapse.

Concussions and Head Injuries in English Community Rugby Union Match Play

Background: Previous research has described general injury patterns in community-level rugby union, but specific information on time-loss head injuries has not been reported. Purpose: To establish the incidence and nature of significant time-loss head injuries in English community rugby match play, and to identify the injury risk for specific contact events. Study Design: Descriptive epidemiology study. Methods: Over 6 seasons, injury information was collected from 46 (2009-2010), 67 (2010-2011), 76 (2011-2012), 50 (2012-2013), 67 (2013-2014), and 58 (2014-2015) English community rugby clubs (Rugby Football Union levels 3-9) over a total of 175,940 hours of player match exposure. Club injury management staff reported information for all head injuries sustained during match play whereby the player was absent for 8 days or greater. Clubs were subdivided into semiprofessional (mean player age, 24.6 ± 4.7 years), amateur (24.9 ± 5.1 years), and recreational (25.6 ± 6.1 years) playing levels. Contact events from a sample of 30 matches filmed over seasons 2009-2010, 2010-2011, and 2011-2012 provided mean values for the frequency of contact events. Results: The overall incidence for time-loss head injuries was 2.43 injuries per 1000 player match hours, with a higher incidence for the amateur (2.78; 95% CI, 2.37-3.20) compared with recreational (2.20; 95% CI, 1.86-2.53) (P = .032) playing level but not different to the semiprofessional (2.31; 95% CI, 1.83-2.79) playing level. Concussion was the most common time-loss head injury, with 1.46 per 1000 player match hours. The tackle event was associated with 64% of all head injuries and 74% of all concussions. There was also a higher risk of injuries per tackle (0.33 per 1000 events; 95% CI, 0.30-0.37) compared with all other contact events. Conclusion: Concussion was the most common head injury diagnosis, although it is likely that this injury was underreported. Continuing education programs for medical staff and players are essential for the improved identification and management of these injuries. With the majority of head injuries occurring during a tackle, an improved technique in this contact event through coach and player education may be effective in reducing these injuries.

Incidence and Nature of Medical Attendance Injuries in English Community Rugby Union

Background: Previous research has identified injury patterns during community-level rugby union match play, but none have investigated the frequency and reasons for on-field injury management. Purpose: To establish the frequency, reasons, and patterns of on-field injury management in English community rugby, including differences between different levels of play. Study Design: Descriptive epidemiology study. Methods: Over 3 seasons, injury information was collected from 46 (2009-2010), 67 (2010-2011), and 76 (2011-2012) English community clubs (Rugby Football Union [RFU] levels 3-9). Club injury management staff reported information for all medical attendances during match play, including details on the injury site and type, playing position (seasons 2010-2011 and 2011-2012 only), and whether the player was removed from play. Clubs were subdivided into groups A (RFU levels 3 and 4 [mainly semiprofessional]; n = 39), B (RFU levels 5 and 6 [mainly amateur]; n = 71), and C (RFU levels 7-9 [social and recreational]; n = 79) to differentiate playing levels. Results: The overall medical attendance incidence was 229 per 1000 player-match hours (95% CI, 226-232), with 45 players removed per 1000 player-match hours (95% CI, 44-46). Attendance incidence for group A (294 per 1000 player-match hours; 95% CI, 287-301) was higher compared with group B (213; 95% CI, 208-218; P < .001) and C (204; 95% CI, 200-209; P < .001). There was a higher incidence of attendances to forwards (254; 95% CI, 249-259) compared with backs (191; 95% CI, 187-196; P < .001). The head was the most common specific site of injury (55 per 1000 player-match hours; 95% CI, 53-57) but the lower limb region overall accounted for most attendances (87; 95% CI, 85-89) and the greatest chance of removal from the pitch (22; 95% CI, 21-23). Conclusion: With the likelihood of 1 injury for each team per match severe enough for the player to leave the pitch and with at least 1 attendance for a head injury per match, there is clear evidence that pitch side staff should be trained to recognize potentially serious injuries.

Effect of combined carbohydrate-protein ingestion on markers of recovery after simulated rugby union match-play

Abstract In this study, we investigated the effect of ingesting carbohydrate alone or carbohydrate with protein on functional and metabolic markers of recovery from a rugby union-specific shuttle running protocol. On three occasions, at least one week apart in a counterbalanced order, nine experienced male rugby union forwards ingested placebo, carbohydrate (1.2 g · kg body mass−1 · h−1) or carbohydrate with protein (0.4 g · kg body mass−1 · h−1) before, during, and after a rugby union-specific protocol. Markers of muscle damage (creatine kinase: before, 258 ± 171 U · L−1 vs. 24 h after, 574 ± 285 U · L−1; myoglobin: pre, 50 ± 18 vs. immediately after, 210 ± 84 nmol · L−1; P < 0.05) and muscle soreness (1, 2, and 3 [maximum soreness = 8] for before, immediately after, and 24 h after exercise, respectively) increased. Leg strength and repeated 6-s cycle sprint mean power were slightly reduced after exercise (93% and 95% of pre-exercise values, respectively; P < 0.05), but were almost fully recovered after 24 h (97% and 99% of pre-exercise values, respectively). There were no differences between trials for any measure. These results indicate that in experienced rugby players, the small degree of muscle damage and reduction in function induced by the exercise protocol were not attenuated by the ingestion of carbohydrate and protein.

Efficacy of a movement control injury prevention programme in adult men’s community rugby union: a cluster randomised controlled trial

Background Exercise programmes aimed at reducing injury have been shown to be efficacious for some non-collision sports, but evidence in adult men’s collision sports such as rugby union is lacking. Objective To evaluate the efficacy of a movement control injury prevention exercise programme for reducing match injuries in adult men’s community rugby union players. Methods 856 clubs were invited to participate in this prospective cluster randomised (single-blind) controlled trial where clubs were the unit of randomisation. 81 volunteered and were randomly assigned (intervention/control). A 42-week exercise programme was followed throughout the season. The control programme reflected ‘normal practice’ exercises, whereas the intervention focused on proprioception, balance, cutting, landing and resistance exercises. Outcome measures were match injury incidence and burden for: (1) all ≥8 days time-loss injuries and (2) targeted (lower limb, shoulder, head and neck, excluding fractures and lacerations) ≥8 days time-loss injuries. Results Poisson regression identified no clear effects on overall injury outcomes. A likely beneficial difference in targeted injury incidence (rate ratio (RR), 90% CI=0.6, 0.4 to 1.0) was identified, with a 40% reduction in lower-limb incidence (RR, 90% CI=0.6, 0.4 to 1.0) and a 60% reduction in concussion incidence (RR, 90% CI=0.4, 0.2 to 0.7) in the intervention group. Comparison between arms for clubs with highest compliance (≥median compliance) demonstrated very likely beneficial 60% reductions in targeted injury incidence (RR, 90% CI=0.4, 0.2 to 0.8) and targeted injury burden (RR, 90% CI=0.4, 0.2 to 0.7). Conclusions The movement control injury prevention programme resulted in likely beneficial reductions in lower-limb injuries and concussion. Higher intervention compliance was associated with reduced targeted injury incidence and burden.

Running demands and heart rate response in rugby union referees.

Abstract Suarez-Arrones, L, Portillo, LJ, García, JM, Calvo-Lluch, A, Roberts, SP, and Mendez-Villanueva, A. Running demands and heart rate response in rugby union referees. J Strength Cond Res 27(11): 2946–2951, 2013—The aim of this study was to examine the match physical demands and exercise intensity associated with men rugby union refereeing using global positioning system technology. Ten male rugby union referees (age, 37.1 ± 5.9 years; body mass, 83.7 ± 4.8 kg; height, 175.5 ± 6.2 cm) were analyzed 2–4 times during a total of 30 national level matches. The average total distance covered by the referees throughout the game was 6,322.2 ± 564.9 m. As a percentage of total distance, 37.3% (2,356.9 ± 291.3 m) was spent walking, 24.1% (1,524.4 ± 229.4 m) jogging, 10.4% (656.2 ± 130.7 m) running at low intensity, 17.6% (1,110.3 ± 212.2 m) at medium intensity, 5.5% (347.1 ± 27.1 m) at high intensity, and 5.2% (328.1 ± 230.3 m) at sprint. A significant decrease (p < 0.05) in running performance was observed between the first and the second halves in the last 3 speed zones. When the total distance traveled during consecutive 10-minute periods was compared, there was a significantly greater distance covered in the first 10 minutes of the game (876.3 ± 163 m) compared with 50–60 minutes (679.8 ± 117.6 m), 60–70 minutes (713.03 ± 122.3 m), and 70–80 minutes (694.2 ± 125.7 m; all p < 0.05). The average heart rate responses were similar (p > 0.05) in the first (157 ± 7 b·min−1; 85% HRmax) and second half (155 ± 7 b·min−1; 84% HRmax). This study provides evidence of reduced high-intensity running toward the end of the game. These findings offer important information to design better training strategies adapted to the requirements and demands of rugby union refereeing.