1. University of Birmingham
MSc Exercise and Sports Medicine (Football)
NEUROMUSCULAR ADAPTATION TO TRAINING
THE EFFECTS OF FIXTURE
CONGESTION IN FOOTBALL:
A CRITICAL APPRAISAL OF THE LITERATURE
Mattia Zambaldi
Birmingham, 29th
April 2014
2. INTRODUCTION
AIM
FIXTURE CONGESTION:
No effect on physical performance
Carling & Dupont, 2010; Carling et al., 2012; Dellal et al., 2013;
Dupont et al., 2010; Rey et al., 2010
Increased injury rates
Bengtsson et al., 2013; Carling et al., 2012;
Dellal et al., 2013; Dupont et al., 2010 ✔
?
To appraise the studies on fixture congestion in football
• Post-match fatigue
• Performance recovery
• Injury rates
3. POST-MATCH FATIGUE
• Glycogen depletion
– most important energy substrate Bangsbo et al., 2007
– 43% and 73% of control at 0 and 24 hrs Krustrup et al., 2011
• Exercise induced muscle damage (EIMD)
– biochemical markers: CK, Mb, UA
– physical performance markers: sprint, CMJ, knee strength
– subjective markers perceived soreness (DOMS)
4.
5. POST-MATCH FATIGUE
• Biochemical markers
– many opportunities but consensus is needed Nédélec et al., 2012
• Physical performance markers
– more consistent tests have not been used
- repeated sprint ability Mohr et al., 2004; Rampinini et al., 2007
- changes of directions Silva et al., 2013
• Subjective markers
– DOMS evaluation limited to intra-individual comparisons
Limitations
6. THE ROLE OF THE BRAIN
• Fatigue is a sensation produced by the brain...
– collation of past experiences, mental fatigue, motivation, sleep quality, feedback from
the environment... and indeed the perceived state of recovery
• Perceived efficacy of an intervention (i.e. recovery) can
influence subsequent performance Beedie and Foad, 2009
...which ultimately down-regulates the motor output Noakes, 2012
• In football...
– post-match performance seems to be more influenced by central rather than peripheral
fatigue mechanisms Rampinini et al., 2011
– mental fatigue: perceptual skills, decision-making, stress, ... Nédélec et al., 2012
– mental fatigue impairs physical performance Marcora et al., 2009
• CNS likely to influence fatigue recovery but currently insufficient
evidence Minett & Duffield, 2014
7. FIXTURE CONGESTION
• Increased injury rates during congested periods
Bengtsson et al., 2013; Carling et al., 2012; Dellal et al., 2013; Dupont et al., 2010
• Higher muscle and ligament injury rates with recovery
≤4 days vs. ≥6 days Bengtsson et al., 2013; Carling et al., 2012
• Higher injury rates suggest that ≤4 days recovery
between consecutive matches is insufficient
• Injuries affect team performance negatively Hägglund et al., 2013
8. FIXTURE CONGESTION
• No differences in athletic performance throughout consecutive
games Carling & Dupont, 2010; Carling et al., 2012; Dellal et al., 2013; Dupont et al., 2010; Rey et al., 2010
– football is not all about physical abilities...
- players involved in more matches prior to the World Cup 2002 were judged to
underperform in that competition Ekstrand et al., 2004
- mid-week international matches negatively affect subsequent domestic league
performance i.e. less points yielded Verheijen, 2012
• ...but some relevant limitations!
– only total and different speed ranges distances were considered (video analysis)
– accelerations can occur at any speed Dwyer and Gabbett, 2012
– number of sprints is underestimated Dwyer and Gabbett, 2012
– need to account for accelerations high energy cost!➔ Osgnach et al., 2010
• at present no conclusions can be drawn on the effects of fixture
congestion on physical performance across consecutive games
• need for more appropriate and sensitive measures of performance
– video analysis not sensitive to vertical forces i.e. jumping Dellaserra et al., 2014
9. FIXTURE CONGESTION
• Use of GPS-accelerometer devices offer great potential
– accurate analysis of jumping, heading and CODs Dellaserra et al., 2014
– reliable if sampling ≥ 10Hz Cummins et al., 2013
– ...but currently not permitted in official competitions
Need for more appropriate and sensitive
measures of performance and recovery
• Still many confounding factors difficult to control for
– players rotation, level of the opponent team, result of the game, climatic and
environmental variables, recovery strategies used... Carling et al., 2012
• Need to focus on acceleration profiles
– new definition of sprinting Dwyer and Gabbett, 2012
– energy cost and metabolic power approach Osgnach et al., 2010
• High quality studies need large samples
– video analysis systems are therefore likely to be more feasible
• Monitoring of recovery markers throughout congested periods
• Investigation of central fatigue mechanisms
– potential for TMS and EMG technologies Goodall et al., 2012; Rampinini et al., 2011
• Comprehensive scale for perceived recovery Kenttä and Hassmén, 1999
