The number of matches played each season varies greatly from one league to another. English and Spanish clubs play no average 65 to 76 matches per season while French clubs play around 50. The risk of overplaying is therefore real, which may lead to a decrease in motivation, concentration and an increased risk of injury and low performance.

Star players must play numerous important matches toward the end of the season, this intense period increases the risk of fatigue, the risk of injury and the risk of under-performing.

266 players among the greatest European clubs, including 65 who played the 2002 World Cup

Arsenal, Manchester United, Real Madrid, Juventus, Inter Milan, Ajax Amsterdam, PSV Eindhoven, Paris Saint-Germain, Stade Rennais and RC Lens all transmitted their data concerning time of play, type and severity of injuries, number of matches… to researchers of this study (1). In addition, a group of three international experts (coach or ex-coach of European national teams) estimated the performances of each player following three criteria: overperformance (above expectations), expected performance and underperformance (below expectations) during the 2002 World Cup that would take place at the end of the season.

The end of the season, a critical period…

During the end of the season, importance of each match increases, especially with the finals of national and European competitions as well as the final phases of European or World cups, every 2 years. The 65 analyzed players, who participated in the 2002 World Cup, played significantly more matches during the season, especially the last 10 weeks, which means that their personal calendar was dense, both physically and emotionally, before and during the cup.

… that impacts performances during the World Cup

29% of the players participating in the World Cup got injured and 32% underperformed. The latter were those who played at least 12 matches during the past 10 weeks. This may indicate that the series of intense matches in short periods increase fatigue, and thus the risk of both injury and underperformance. The link seemed so strong that UEFA modified the Champions League calendar as of 2003/2004 to enable longer end-of-season recovery before European and World cups.  

What about COVID?

Not only did the various lockdowns and restrictions impacted fatigue in addition to physical and mental preparation (2), but they also strongly impacted schedules of competition, with frequent periods of important matches close together. In this context, the use of an accurate predictive tool, anticipating fatigue states up to weeks in advance, is more important than ever for professional football clubs. And inCORPUS® is the only tool capable of providing such accuracy, specifically for elite sport and particularly football.

Scientific references

(1)          Ekstrand, J.; Waldén, M.; Hägglund, M. A Congested Football Calendar and the Wellbeing of Players: Correlation between Match Exposure of European Footballers before the World Cup 2002 and Their Injuries and Performances during That World Cup. Br. J. Sports Med. 2004, 38 (4), 493–497.

(2)          Bourdillon, N.; Yazdani, S.; Schmitt, L.; Millet, G. P. Effects of COVID-19 Lockdown on Heart Rate Variability. PloS One 2020, 15 (11), e0242303.

article author image
Nicolas Bourdillon
Chief Research Officer – PhD in Physiology