Football after COVID — Match Congestion & Injury Risk

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Executive Summary:

  • Injury risk increases significantly when more than 6 matches are played over 30 days.
  • This ‘threshold’ should be taken into consideration by Football federations when planning the remainder of the 2020 season, if possible.
  • Lineup rotations can help by avoid playing over 6 matches per 30 days.
  • Personalized training is crucial to ensure recovery for players that play regularly and match readiness for those that don’t.
  • Data suggests that teams with high squad availability (associated with lower injury rates) will succeed beyond expectations. Tracking, analyzing and acting on performance data is a critical component of such success.

Suspension of all major football leagues due to the COVID-19 pandemic has the sport operating in uncharted territories. Players are resting or training at home for several weeks now, and will probably continue to do so for at least another month according to the most optimistic forecasts. For the European Football leagues, this situation creates a paradox, as some players haven’t enjoyed such a rest period in years. However, if football governing authorities decide to play out the season, they might have to face a schedule that’s more congested than ever before and play matches every two-three days during the hot summer.

If this scenario takes place, teams will need to monitor their players’ activities during the break, create short “preseason-like” training protocols to get players match-ready in time for the resume of play and form intelligent training routines to recover players as much as possible between games.

But before addressing each of these challenges, We believe it should be highly beneficial to understand how injury risk reacts during the season and how it’s expected to react during a consequent period of playing matches every three days.

This is where our work at Zone7 comes into play. Zone7 is an artificial intelligence platform that can detect 70% of injuries up to 7 days before they occur, whilst providing alerts for no more than 3 players (10%-15% of a squad) during the vast majority of days. Our deep-learning algorithms use inputs such as workload tracking from training and matches, injury history, sleep data, fitness tests, biomarkers, etc. Over the last three years, we’ve generated daily risk forecasts for over 30 different teams and integrated with the vast majority of wearable devices in the market. This enables us to provide insights regarding the seasonality of injury risk and how injury risk responds to highly congested periods.

To generate these insights, we’ve analyzed injury risk trends based on data from multiple teams from Spain, Italy, England, France, and the United States. All play in their respective top divisions. Overall, the analysis consists of 4000 different days. Risk levels are represented by a team-wide summary of the injury probabilities provided by Zone7 for each player on each given day (these probabilities represent the likelihood of a player to sustain an injury in the upcoming seven days).

Generally speaking, injury risk is a seasonal attribute and is sensitive to match congested periods and even more so to inconsistencies in a team’s playing schedule. In further detail, looking at the European teams, we see that risk levels rise from the beginning of the official match schedule and peaks at around late September- early October which is when playing minutes start to accumulate and the group stages of European competition begin. It is also a period of many fluctuations in teams’ schedules due to many international breaks that take place between September and November. We see another spike in risk levels around just before the Winter break that takes place in most leagues. Naturally, during the break risk levels drop. However, in English teams, such a reduction isn’t apparent, as they cope with a hectic schedule with many matches during this time. During the second half of the season, we see an additional increase in risk levels towards March, which is when the accumulated playing time induced by the resumption of European competitions, creates an effect.

Addressing the match congestion issue directly, we’ve examined the behavior of injury risk compared with the number of games a team played in the 30 days prior to each given day.

As we can see in the graph below, risk levels are almost non-existent in days that 2 matches or less were played in the 30 days preceding them. Looking at days that followed a 30 day period with 3 matches or more, we can see there’s a significant increase in risk levels following 7–8 games in 30 days compared to 3–5 games during this time period. In fact, a 30 day period with 8 matches can cause risk levels that are over 25% higher than a 30 day period with 3–5 matches. That’s highly worrying, assuming we’re looking at that type of schedule if the 19/20 season is to be completed.

Additionally, under the assumption our database is representative of schedules in professional football leagues, a situation in which 8 matches were played in the 30 days prior to a given day occurs only 4% of the time. Emphasizing further that players will deal with a situation they aren’t well prepared for.

UEFA published a few days ago a decision to postpone all European club competition-related deadlines until further notice (April 1). This decision presents a possibility to complete domestic leagues until July-August and if the COVID-19 situation will be brought under control sooner rather than later, insights regarding injury risk and fixture schedules like the ones presented above can be taken into account. If not, and teams will have to play their remaining 10–15 matches in a very short period of time, they will also have to find unique solutions to come out of a period they’re not necessarily prepared for as successfully and injury-free as possible.

Such solutions might have to require squad rotations when possible but they should also address training routines. A problem that comes along with match congested periods is the teams’ inability to perform some of the training sessions they do when they have more time between matches. Especially the more intense ones that help get players match ready. Therefore match congestion might have an effect on the readiness of players who won’t play regularly, alongside the risk inducing effect it has on those that will. It is a situation that will require teams to adapt and use highly personalized training regimes in order to have as many players healthy and match-ready as possible. The past shows that teams that do, will be more successful than those that don’t.

We at Zone7 believe we can help teams navigate such a reality and support decision making with the data-driven insights our AI platform provides — Objective injury risk assessments for every training session or match, performed or planned. We believe that we are in a unique position to do so, as we’ve analyzed more performance data from match congested periods, with respect to injury risk than any other company organization. These are challenging times for the world of football. As part of the football family, we intend to do our best to help clubs during the remainder of the season, if and when it resumes and in whichever form. If you’d like to hear more details, please contact us.