Movement Patterns and Muscle Damage During Simulated Rugby Sevens Matches in National Team Players

• Lucas A. Pereira ; Fábio Yuzo Nakamura ^[1] ; José E. Moraes ^[2] ; Katia Kitamura ; Solange de Paula Ramos ; Irineu Loturco
  1. [1] State University of Londrina
  2. [2] Brazilian Rugby Confederation, São Paulo
• Localización: Journal of strength and conditioning research: the research journal of the NSCA, ISSN 1064-8011, Vol. 32, Nº. 12, 2018, págs. 3465-3474
• Idioma: inglés
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• Resumen

  • The aim of this study was to analyze the match performance (i.e., distance covered in different intensities), signs of muscle damage (assessed by means of creatine kinase [CK] activity and rate of force development [RFD]), and neuromuscular fatigue (using linear sprint and vertical jump performances) after 3 single-day simulated matches performed by rugby sevens players from the Brazilian National team. Ten male rugby sevens players (25.2 ± 3.6 years; 88.7 ± 7.1 kg; 182.2 ± 6.3 cm) participated in this study. On the day before the matches, the athletes performed a 40-m sprint, a vertical jump assessment, and a maximal isometric force test. In the morning of the match day, blood samples were collected to analyze the CK activity. Afterward, 3 simulated rugby sevens' matches were performed with 2-hour intermission periods. The match performance (encompassing total distance and distance covered in different velocity ranges and body loads [BLs]) was obtained from global positioning system units. The statistical analysis was performed using a mixed model approach and the effect sizes (ESs) of the differences. The statistical significance level was set at p <= 0.05. Players were capable of maintaining the match performance when comparing the first and last games. Large (ES > 0.8) and significant (p <= 0.05) reductions were demonstrated in the total distance and BL when comparing the second with the first halves. Decrements in the explosive force capacity (assessed by means of RFD) and the squat jump (SJ) were noticed (ES varying from 0.55 to 1.14; p <= 0.05). The CK activity increased after the matches (ES = 1.29; p <= 0.05). The rugby sevens players were able to maintain the physical performance across 3 successive matches simulating the first day of a tournament. The augmented CK activity and the decreases in the SJ and RFD suggest that increased levels of muscle damage were experienced on the day after the matches. Therefore, the technical staff are encouraged to implement recovery strategies and planned substitutions during multiday tournaments to reduce the impact of accumulated fatigue and muscle damage on subsequent match performance. In addition, specific training strategies aimed at better simulating the match demands need to be implemented in the players' training routines.