Fixture Congestion and the Physical Response to Soccer: Implications for Knee Flexor Injury Risk

Student thesis: Doctoral Thesis


Congested activity schedules are common in soccer, with implications for impaired performance and increased injury risk. It has recently been suggested that valid soccer-specific exercise protocols (SSEP's) may offer a unique opportunity to assess the physical demands associated with periods of fixture congestion. Fixture congestion in the current thesis is defined as a high frequency of soccer-specific activity performed with less than or equal to seventy-two hours of recovery interspersing successive bouts. Study one describes the development of a novel treadmill-based SSEP characterised by clusters of high intensity (HI) efforts. The SSEP was validated against the velocity profile and total distance (TD) covered, and elicited a physical response comparable to match-play. Study two utilised the same SSEP to consider the physical response associated with successive bouts of soccer-specific activity interspersed with either 48 or 72h recovery. There was no difference in the fatigue response associated with two soccer simulations, with 48 h sufficient for full recovery of the physiological and PlayerLoadTM data. The 48 h recovery was therefore applied in Study three, where three games in a week is typically the worst case scenario for fixture congestion. Study three quantified the cumulative and residual physiological and biomechanical response associated with the completion of three successive bouts of the SSEP, completed with 48 hrs recovery between each trial. Study three also assessed the physical response associated with successive bouts of different exercise modalities (continuous, repeat-sprint, and intermittent), specific to the demands of the SSEP. The physical response was specific to each activity modality, but the volume of work and number of HI efforts performed across the three SSEP's elicited a mechanical and muscular emphasis with residual fatigue. Study four attempted to assess the effectiveness of an interchange rule on reducing the cumulative and residual physical fatigue response associated with the completion of the SSEP. The interchange rule appeared to elicit a positive effect on the physiological and perceptual response to, and rate of mechanical recovery following the completion of the SSEP. Study five focused on developing and assessing the effectiveness of a novel post-match active recovery protocol on aiding the rate of post-trial mechanical and perceptual recovery. The active recovery protocol had a positive effect on the eccentric knee flexor angle of peak torque data recorded at 300 deg·s-1. The current series of studies offers a mechanistic understanding of the physical response associated with periods of short-term fixture congestion in soccer. The current studies have implications for the design and micro management of training and competition schedules, and the contemporary use of biomechanical analyses to quantify markers of performance and injury
Date of Award7 Oct 2015
Original languageEnglish
Awarding Institution
  • Edge Hill University
SupervisorMATT GREIG (Director of Studies) & KELLY MARRIN (Supervisor)


  • Biomechanics
  • fatigue
  • Fixture Congestion
  • injury
  • physiology
  • recovery
  • soccer

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