Running Demands and Heart Rate Response in Rugby Sevens Referees

Olympic Sports Science-Bibliometric Analysis of All Summer and Winter Olympic Sports Research

Introduction: The body of scientific literature on sports and exercise continues to expand. The summer and winter Olympic games will be held over a 7-month period in 2021-2022. Objectives: We took this rare opportunity to quantify and analyze the main bibliometric parameters (i.e., the number of articles and citations) across all Olympic sports to weigh and compare their importance and to assess the structure of the "sport sciences" field. The present review aims to perform a bibliometric analysis of Olympic sports research. We quantified the following topics: (1) the most investigated sports; (2) the main journals in which the studies are published; (3) the main factors explaining sport-specific scientific attractiveness; (4) the influence of being in the Olympic programme, economic weight, and local influences on research output; and (5) which research topic is the most investigated across sports. Methods: We searched 116 sport/exercise journals on PubMed for the 40 summer and 10 winter Olympic sports. A total of 34,038 articles were filtered for a final selection of 25,003 articles (23,334 articles on summer sports and 1,669 on winter sports) and a total of 599,820 citations. Results and Discussion: Nine sports [football (soccer), cycling, athletics, swimming, distance & marathon running, basketball, baseball, tennis, and rowing] were involved in 69% of the articles and 75% of the citations. Football was the most cited sport, with 19.7 and 26.3% of the total number of articles and citations, respectively. All sports yielded some scientific output, but 11 sports (biathlon, mountain biking, archery, diving, trampoline, skateboarding, skeleton, modern pentathlon, luge, bobsleigh, and curling) accumulated a total of fewer than 50 publications. While ice hockey is the most prominently represented winter sport in the scientific literature, winter sports overall have produced minor scientific output. Further analyses show a large scientific literature on team sports, particularly American professional sports (i.e., baseball, basketball, and ice hockey) and the importance of inclusion in the Olympic programme to increasing scientific interest in "recent" sports (i.e., triathlon and rugby sevens). We also found local/cultural influence on the occurrence of a sport in a particular "sport sciences" journal. Finally, the relative distribution of six main research topics (i.e., physiology, performance, training and testing, injuries and medicine, biomechanics, and psychology) was large across sports and reflected the specific performance factors of each sport.

Physical Demands of Refereeing Rugby Sevens Matches at Different Competitive Levels

Sant'Anna, RT, Roberts, SP, Moore, LJ, and Stokes, KA. Physical demands of refereeing rugby sevens matches at different competitive levels. J Strength Cond Res XX(X): 000-000, 2019-The aim of this study was to compare the physical demands of officiating across different competitive levels in rugby sevens. An observational design was used involving 27 referees (26 men and 1 woman, age: 27 ± 6 years, body mass [mean ± SD]: 78.5 ± 9.3 kg, and height: 179 ± 5 cm). Global Navigation Satellite Systems data were collected across a total of 114 matches during 5 separate rugby sevens tournaments played in England-between May and July 2018-categorized into 4 competitive levels: (a) international, (b) professional, (c) semiprofessional, and (d) amateur. Compared with referees officiating at the international, professional, and semiprofessional levels, referees officiating at the amateur level covered less total (p < 0.001) and relative distance (p < 0.001). In addition, these referees covered more distance walking and jogging (p < 0.001). Amateur referees also completed fewer sprints (p = 0.006), repeated high-intensity efforts (RHIEs) per game (p < 0.001), and spent longer between RHIEs (p = 0.015). Finally, for the amateur referees, the duration of the longest repeated high-intensity bout (i.e., worst case scenario) was lower (p < 0.001), with less distance covered (p < 0.001) and fewer high-intensity accelerations (p < 0.001). Refereeing rugby sevens is therefore more physically demanding at higher competitive levels, particularly in terms of high-intensity efforts. The results provide vital information for practitioners involved in the physical preparation of rugby sevens referees.

Physical and Physiological Demands of Elite Rugby Union Officials

PURPOSE

To examine the movement and physiological demands of rugby union officiating in elite competition.

METHODS

Movement demands of 9 elite officials across 12 Super Rugby matches were calculated, using global positioning system devices. Total distance (in m), relative distance (in m·min^-1), and percentage time spent in various speed zones were calculated across a match. Heart-rate (HR) responses were also recorded throughout each match. Cohen d effect sizes were reported to examine the within-match variations.

RESULTS

The total distance covered was 8030 (506) m, with a relative distance of 83 (5) m·min^-1 and with no differences observed between halves. Most game time was spent at lower movement speeds (76% [2%]; <2.0 m·s^-1), with large effects for time spent >7.0 m·s^-1 between halves (d = 2.85). Mean HR was 154 (10) beats·min^-1 (83.8 [2.9]%HR_max), with no differences observed between the first and second halves. Most game time was spent between 81%HR_max and 90%HR_max (40.5% [7.5%]) with no observable differences between halves. Distances covered above 5.1 m·s^-1 were highest during the first 10 min of a match, while distance at speeds 3.7 to 5 m·s^-1 decreased during the final 10 min of play.

CONCLUSIONS

These findings highlight the highly demanding and intermittent nature of rugby union officiating, with only some minor variations in physical and physiological demands across a match. These results have implications for the physical preparation of professional rugby union referees.

Match analysis and temporal patterns of fatigue in rugby sevens

Rugby sevens is a rapidly growing sport. Match analysis is increasingly being used by sport scientists and coaches to improve the understanding of the physical demands of this sport. This study investigated the physical and physiological demands of elite men's rugby sevens, with special reference to the temporal patterns of fatigue during match play. Nine players, 4 backs and 5 forwards (age 25.1 ± 3.1 years) participated during 2 "Roma 7" international tournaments (2010 and 2011). All the players were at the professional level in the highest Italian rugby union, and 5 of these players also competed at the international level. During the matches (n = 15), the players were filmed to assess game performance. Global positioning system, heart rate (HR), and blood lactate (BLa) concentration data were measured and analyzed. The mean total distance covered throughout matches was 1,221 ± 118 m (first half = 643 ± 70 m and second half = 578 ± 77 m; with a decrease of 11.2%, p > 0.05, Effect Size [ES] = 0.29). The players achieved 88.3 ± 4.2 and 87.7 ± 3.4% of the HRmax during the first and second halves, respectively. The BLa for the first and second halves was 3.9 ± 0.9 and 11.2 ± 1.4 mmol·L, respectively. The decreases in performance occurred consistently in the final 3 minutes of the matches (-40.5% in the distance covered per minute). The difference found in relation to the playing position, although not statistically significant (p = 0.11), showed a large ES (η = 0.20), suggesting possible practical implications. These results demonstrate that rugby sevens is a demanding sport that places stress on both the anaerobic glycolytic and aerobic oxidative energy systems. Strength and conditioning programs designed to train these energy pathways may prevent fatigue-induced reductions in physical performance.