Rugby Science Update 13
The objective of this study was to describe the Head acceleration events (HAE) burden across various age groups, ranging from U13 to Senior Premier Club level, and the different playing positions during both matches and training. Data were gathered using Prevent Biometric instrumented mouthguards (iMG) throughout the 2023 community rugby season, involving 328 male rugby players in 48 matches and 113 training sessions across U13, U15, U19, and Senior Premier men levels. All iMGs were equipped with an embedding sensor, triaxial accelerometer and gyroscope to detect ‘on-tooth’ time, as well as linear and angular kinematics, respectively. Additionally, all rugby sessions were recorded. Despite similar rugby exposure time across age grades, the percentage of HAE exposure increased with higher age grade, reflecting elevated match intensity as players matured. Notably, 65% of HAEs occurred during matches for the Senior Premier level, with significantly smaller proportions during matches as age decreased. The study revealed a decline in HAE exposure during training with age. Furthermore, the relative risk of experiencing a high magnitude HAE was found to be is 1.36 times higher for U19 players compared to other levels. When analysing player positions, forwards exhibited a higher HAE exposure rate than backs, particularly in the tackle and ruck events, likely attributed to increased contact for forwards. Interestingly, at the U13 level, backs experienced more low-magnitude HAE during training sessions, presenting an opposite position incidence to Senior Premier players. Tackles accounted for 66–75% of HAE exposure in matches, emphasizing the authors recommendation for the importance of tackle and ruck technique training, particularly for higher grade players.
This study is published in Sports Medicine.
The purpose of this review is to discuss the current knowledge regarding the relationship between body composition (BC) and athletic performance across different ages and sports. Additionally, the review aims to survey the evolution of BC considerations in international sport over the last decade and provide best practice recommendations for BC considerations to prevent potential health and performance consequences. A review search was conducted on PubMed in August 2022 and December 2022, focusing on exploring the impact of athletes’ BC on performance outcomes. The review includes a total of 29 studies, with most of them involving well trained athletes in individual sports. To address the evolution of BC considerations over the last decade, an electronic questionnaire was developed and circulated via social media and email lists. The survey included 125 practitioners from 26 countries working within competitive sports. The findings of this review indicate limited evidence regarding the association between BC and competitive success. Notably, endurance athletes ten to benefit from leanness, and muscle mass is crucial across various sports. Overall, persistent training and experience are essential for talent development and performance success. The survey results highlight the necessity for a more holistic approach to using and reporting BC data over the past decade. Practitioners emphasize the need for awareness and education on how BC assessment affects both performance and health. The survey also highlights that methods have remained largely unchanged over the decades, with practitioners still comparing arbitrary sport-specific ideal BC. The authors emphasize the importance of approaching BC assessments and reporting BC data appropriately. They recommend assessing BC only when necessary and providing the necessary support for athletes to avoid potential health risks. To mitigate these risks, pre-screening should be conducted by the medical and performance team. Testing protocol should be chosen wisely, with a recommended frequency not exceeding 4-6 times a year. Additionally, BC assessment for athletes under the age of 18 is not recommended.
This study is published in British Journal of Sports Medicine.
The primary aim of this study was to investigate changes in player and referee behaviour following the implementation of the lowered (armpit) legal tackle height law variation intervention in amateur community rugby. Additionally, the study aimed to assess on-field referee sanctioning decisions for illegal high tackles. Building on a prior study which implemented the lowered (armpit) legal tackle height law intervention in the amateur community rugby, this research examined referee and player behaviour across three periods of the season. The study involved 42 teams participating in the university rugby club’s four-league, inter-residence competition with the inclusion of 16 referees from the South African Referees Academy. All matches were recorded and video footage from the mounted Go Pro on the referees was captured. Evaluation of on-field referee sanctioning was carried out by a professional South African Rugby Union (SARU) international-level referee, which assessed all videos coded as ‘high’ under the new law variation. The findings of the study revealed a positive on-field behaviour change in both players and referees following the new law variation. There was a significantly higher sanctioning rate by the referees in the middle period of the session, potentially contributing to a significant reduction in upright tackles in the last part of the season. Additionally, there was a fair agreement between the independent referee evaluation and the on-field sanctioning when reviewing the high tackles.
This study is published in the Journal of Science and Medicine in Sport.
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