Influence of an intensified competition on fatigue and match performance in junior rugby league players

Johnston, Rich D. and Gabbett, Tim J. and Jenkins, David G. (2013) Influence of an intensified competition on fatigue and match performance in junior rugby league players. Journal of Science and Medicine in Sport, 16 (5). pp. 460-465. ISSN 1878-1861

Abstract

Objectives: The aim of this study was to assess the physiological responses to an intensified rugby league competition and explore the relationships between fatigue and match performance. Design: Prospective cohort study. Methods: Fifteen junior rugby league players (n= 8 forwards, 7 backs; mean ± SE, age 16.6 ± 0.2 years; body mass 81.6 ± 3.0. kg; and height 178.9 ± 1.8. cm) competed in five 40. min games over 5 days (two games each on days 1 and 2, one game on day 4, and no games on days 3 and 5). Over the competition, players performed a countermovement jump to assess neuromuscular fatigue, provided a fingertip blood sample to measure blood creatine kinase, and completed a questionnaire to monitor perceived wellbeing; ratings of perceived effort were recorded following each game. Global positioning system and video analysis of each game were used to assess match performance. Results: Over the first 3 days, there were progressive and large increases in neuromuscular fatigue which peaked 12. h after game 4 (forwards ES = 4.45, p= 0.014; backs ES = 3.62, p= 0.029), and muscle damage which peaked 1. h post game 4 (forwards ES = 4.45, p= 0.004; backs ES = 3.94 p= 0.012), as well as reductions in perceived wellbeing. These measures gradually recovered over the final 2 days of the competition. Compared to the backs, the forwards experienced greater increases in creatine kinase following game 2 (ES = 1.30) and game 4 (ES = 1.24) and reductions in perceived wellbeing (ES = 0.25-0.46). Match intensity, high-speed running, and repeated-high intensity effort bouts decreased in games 4 and 5 of the competition. Small to large associations were observed between the changes in fatigue, muscle damage and match performance, with significant correlations between creatine kinase and repeated high-intensity effort bout number (r= -0.70, p= 0.031) and frequency (r= 0.74, p= 0.002) and low-speed activity (r= -0.56, p= 0.029). Conclusions: Fatigue and muscle damage accumulate over an intensified competition, which is likely to contribute to reductions in high-intensity activities and work rates during competition.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Published version cannot be displayed due to copyright restrictions.
Faculty / Department / School: No Faculty
Date Deposited: 19 May 2017 03:49
Last Modified: 19 May 2017 03:49
Uncontrolled Keywords: game intensity; GPS; muscle damage; neuromuscular fatigue; team sports; physiology; work and sport; physiology; muscle physiology; occupational health and industrial medicine; work environment; physical factors; occupational health and industrial medicine; work and health; musculoskeletal system and the back; occupational health and industrial medicine; life style; sport and leisure
Fields of Research : 11 Medical and Health Sciences > 1106 Human Movement and Sports Science > 110699 Human Movement and Sports Science not elsewhere classified
Socio-Economic Objective: C Society > 92 Health > 9299 Other Health > 929999 Health not elsewhere classified
Identification Number or DOI: 10.1016/j.jsams.2012.10.009
URI: http://eprints.usq.edu.au/id/eprint/32331

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