Photo: Martin Meissner
After a 66-day hiatus, Germany’s Bundesliga became the first major sporting league to venture into the post-lockdown era, as the country’s top football tiers controversially returned to action over the weekend. Whether the move was bold or foolish is still up for debate, but the decision to opt for an economy-friendly approach comes as little surprise considering that half of Germany’s top clubs are depending on €300m in TV revenue for survival. Although the stands were empty aside from some cardboard cutout fans, games reached record viewership, attracting millions of sport-starved fans from around the globe. Some were watching more closely than others, as leagues and teams across the world plot comebacks of their own. With the AFL given the green light for a mid-June return, the resumption of the Bundesliga provided a cheat sheet on how to (or how not to) return, and some preliminary insight into what we can expect if and when the rest of the world kicks off over the next weeks.
A 51-page report by the German Football League (DFL) was enough to get the federal government onside with the restart. Protocols included substitutes being seated in the stands rather than on the bench, and players celebrating goals with their elbows or feet to avoid the typical embraces. However, most central to the ongoing strategy is the mass testing of players and staff, who undergo at least three tests per week. Similar to the setup for the AFL’s hub in southern Queensland, players have also been required to live in hotel quarantine for the week leading up to kick-off. Any doubts over how seriously they were taking things were quickly dispelled when Augsburg’s new head coach missed his first game in charge because he left quarantine to buy toothpaste and was subsequently removed from the team. Despite minor corona breakouts at some clubs, games went ahead largely uninterrupted, and it seems that Schalke took social distancing to heart, allowing Dortmund to bang home four goals without reply in the highly anticipated Revierderby.
Aside from the obvious fears regarding corona, key figures within the Bundesliga and beyond have raised additional concerns about a potential surge in injuries caused by rushing back into the season. Karlsruher’s Marc Lorenz made no attempt to veil his disapproval, declaring that the league “hadn’t considered the health of the players at all…. We can expect serious fatigue and injuries”. Fabio Capello, who steered teams to league titles in Italy and Spain, even claimed that he fears injuries more than the virus. Similar, though less dramatic, concerns have echoed across the world’s sporting leagues, including the NBA and the AFL.
Are the concerns about injuries valid?
Forget what they say about Kawhi Leonard - load management is king, but the relationship between training load and injury is fickle. As a general model, the balance between short-term training load and long-term training load is critical, with rapid increases in short-term load leaving athletes vulnerable to injury in the absence of appropriate longer-term load. Even under normal circumstances, injuries are an ever-present part of the game, and the risk is amplified under fatigue. For example, world football injuries occur more frequently later in games, and Bundesliga players suffer from injuries at greater rates later in the season. But when these existing risks are combined with limited pre-season preparation, the frequency of injury skyrockets. The most compelling evidence of this phenomenon comes courtesy of the 2011 NFL lockout. Following a league-wide pay dispute which prevented players from accessing team facilities for 136 days, pre-season training camps were cut from the typical 14 weeks to just 17 days. In the first 12 days of training camp, 10 players ruptured their Achilles tendon and the number of injuries recorded within the first month of the return was more than double the average typically observed over an entire season.
A fundamental problem when teams have little time to prepare is attempting to make up for lost time by slamming players with too much training load after a period of substantially reduced training load (i.e. lockdown). This rapid load slingshot is an easy trap to fall into. However, the injury equation takes into account not simply how long teams have to prepare, but also how they invest their limited preparation time. Coaches are forced to prioritise, and there’s a tendency for general physical preparation to take a backseat behind training that is more closely aligned with winning games, such as skill and tactical work.
The post-lockdown return of sport shares strikingly similar ingredients to the NFL lockout – an inability to access facilities for an extended period of time, the inevitable deterioration of physical qualities that protect against injury, and a shortened timeframe for structured physical preparation. The fate of the teams and their ultimate success relies on the ability of coaching staff to successfully manage the restart process. But organising bodies are also playing their part, with the usual limit of three substitutions in the Bundesliga temporarily increased to five in an attempt to reduce the burden on players.
Bundesliga by the numbers
So just how under or overdone were the players on their return? After trawling through the GPS statistics and crunching the numbers, a few interesting insights emerged from the first weekend of Bundesliga action:
It might come as a surprise but, on average, teams were able to preserve their pre-lockdown physical performances in the first game back. In fact, the league-wide averages for post-lockdown matches were within 1% of the pre-lockdown season averages for both team sprint volume and total team distance covered, which was likely facilitated by the increased substitution allowance. But just like I’m not Brad Pitt, this isn’t Moneyball. Crude GPS stats can provide a consumable narrative on the condition of players, but there are more advanced measures of game dynamics which provide contextual insight for clubs. Although teams were able to preserve their general physical outputs for now at least, it came at a high price.
The most remarkable observation of the Bundesliga return is perhaps also the least surprising. In the 2019/2020 pre-lockdown season, the league saw around .27 injuries per game, whereas the first week of post-lockdown Bundesliga action produced .88 injuries per game. That’s a 226% increase in the rate of injuries, although it’s an inevitably small sample size, and the number is inflated by teams taking a cautious approach to injury classification on the weekend. The common media assertion that eight muscle injuries occurred within the first six games is ambitious, given that a number of these muscle issues were simply fatigue-related cramp. However, adding insult to injury is that match stats don’t reveal the true extent of the injuries – issues were piling up long before the first whistle and, although you wouldn’t know it if you checked the scoreboard, Dortmund were the hardest hit. Since the start of May, four regular starters have succumbed to injuries, and were all absent from the starting line-up against Schalke. And, in what was meant to be a day of celebration for 17-year old sensation Gio Reyna, his first gig as a starter was foiled by a minor injury during warm-up. His replacement in the team, Thorgan Hazard, limped off with cramp in the 79th minute. Dortmund’s spate of injuries may reflect an ambitious return to post-lockdown loading in a bid to win their first league title since 2012, after missing out by just two points last season and sitting four points shy of Bayern München in the current one. As a clash with Bayern looms next week, trying to play catch up on load may catch up with them as the season continues, but that’s the price they pay for not reading Trackademic’s post on loading under lockdown. Of course, the other option is that it’s all an elaborate ploy to buy their stars some more time to get back into match shape ahead of their top of the table clash. Astutely aware of Schalke’s on-field woes before the break, Dortmund were comfortable sending in their B-squad (plus the prolific Haaland) to dispatch of them in the first game back. In support of this conspiracy theory is that Dortmund posted their lowest sprint volume for the season, down by a staggering 24% on their 2019/2020 season average, and were also down 7% on their season average for distance covered. This is likely the product of an active pacing strategy designed to save the next gear for when it matters most against Bayern. I was definitely joking when I started to write this last section, but I may have just stumbled across and exposed an elaborate Dortmund ruse (not to be confused with Reus, Dortmund’s captain who is conveniently also injured) to buy some valuable loading time and lull Bayern into a false sense of security. We won’t have to wait long to find out.
The use of substitutions by teams was a beacon of load management, as most coaches capitalised on the increased allowance. Teams playing in games decided by less than a goal were more reluctant to use their full quota, which may reflect a belief that a fatigued star provides more match-winning value than a fresh bloke who is a perpetual benchwarmer. Leipzig for example, only used three subs on their way to a draw with Freiburg, dropping valuable points in a game they were favoured to win. While the AFL likely won’t suffer from as much bench anxiety as Leipzig, recent history suggests that the NBA might.
The verdict: what does this mean for other sports?
The results offer a clear warning to other teams plotting their own returns that will likely get louder in the coming weeks - preserving physical performance comes at a cost if the retraining process isn’t carefully managed.
Some teams handled the process better than others, and the success of the restart depends on the approach to the uncertain timeframe of the lockdown. For example, some teams took measures to ensure that training rhythms during lockdown mirrored a typical training week, whereas others used the opportunity to take a step back, recover and rebuild. But the good news is that if other codes didn’t like what they saw when they gazed into the crystal ball of the Bundesliga, they have some time up their sleeve to alter their trajectory. The AFL is slated for a June 11th return with a blockbuster clash between Collingwood and Richmond, and the return of players to team facilities this week gives coaches three weeks to nail the process. Although the transition to full contact training is not ideal, it’s better than the circumstances afforded to some Bundesliga clubs. The bad news, however, is that footy has an inherently higher injury rate than world football.
What can teams do? Teams needs to resist the urge to blindly jump straight into regular programming to make up for lost time. Acquiring baseline measures of physical capacities when players return to team facilities should be a priority in order to appropriately assess the damage and evaluate injury risk on an individual basis. Promptly reinstating any training load monitoring processes is also essential, and since tolerance to external load has likely shifted, measures such as heart rate variability and ratings of perceived exertion will be particularly valuable in making sensible load prescription and progression decisions. Importantly, this includes appropriate exposures to general physical preparation like sprinting and strength work alongside skill and tactical training. It’s notoriously difficult to squeeze in meaningful load during the season once the ball is rolling, and the typical 48-hour post-game recovery window may be further extended under the current circumstances, so teams need to be prepared to be flexible with their typical structures. Finally, coaches should note that appropriate management of substitutions allows them more control over the fatigue status of their players, and this may have facilitated a preservation of physical output in the first week of the Bundesliga.
What can leagues do? Just like the Bundesliga’s substitution update, the AFL will introduce a series of rule tweaks that will dampen the physical burden on players, said to include the shorter quarters we saw in round 1, and the addition of longer breaks between quarters and between goals. The traditional rolling substitutions allowance of the AFL will also give teams more control over the fatigue status of their players than world football. But perhaps the most important consideration for returning leagues is fighting the temptation to congest the schedule in order to cram in a certain number of games – an idea already floated by the AFL when corona was first emerging. Even under regular circumstances, a congested match schedule elevates injury occurrence. Across the remainder of the season, the Bundesliga have two mid-week rounds, and if their cup campaign goes to plan, Frankfurt could be facing 12 matches within 49 days – that’s a game every four days on a base of limited physical preparation. Let’s hope the powers of the AFL are tuning in, because in the post-lockdown season, where physical preparation has been severely limited, unnecessary match congestion ensures that nobody wins.
At the end of the day, we’re lucky to be at the point where we’ve escaped the wrath of corona enough to be switching our attention to sports again. We’re not in the clear yet, and some players understandably have concerns about returning to work. But if leagues successfully navigate the post-lockdown challenges and seasons continue to completion, we may be in for a wild ride considering the impact of injuries on the odds of winning a championship. For now, it’s only the tip of the iceberg, and the true impact of the lockdown will only be unmasked as the seasons roll on.