CNN  — 

Walking through the corridors of Bayer Leverkusen’s BayArena, you get the sense this is a club proud of its past.

Trophies take pride of place in glass cabinets, framed shirts of club legends adorn the walls and artistic graffiti depicts famous nights in the club’s history.

But it’s something going on in the rooms deeper inside the stadium that is ensuring Leverkusen is keeping its eye very much on the future.

The Bundesliga side are one of several top level European clubs, as well as NBA and NFL teams, using Catapult Sports technology to help analyze player performance.

Using a highly sensitive GPS tracker – inserted into a training vest between the shoulder blades – the data provides a detailed breakdown of an individual’s top speed, acceleration, distance covered, deceleration and weight distribution, among other statistics.

Gone are the days of slacking off in training. Players can be held accountable for their performances – and how they look after their bodies in between.

“The focus on fitness now is absolutely huge, there’s just no other way,” Kevin Volland, Leverkusen’s club record signing, tells CNN.

“Maybe 10-20 years ago, you could have a beer or two,” he quips.

LEVERKUSEN, GERMANY - MARCH 06: Tayfun Korkut  the newly appointed head coach of Bayer Leverkusen leaves after the training on March 6, 2017 in Leverkusen, Germany. (Photo by Maja Hitij/Bongarts/Getty Images)
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The why? and the what?

The data is used to devise specific training and recovery plans to cater for a player’s strengths and weaknesses.

“It’s pretty incredible what’s (technology) out there these days,” Volland says. “It can be a little more stress for players and the whole team but it’s all part of it, everyone benefits from it.

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“All the fitness trainers then know where you stand, so you can build up your condition and get to what’s ideal for you in particular.”

For football clubs and in particular their players, the “why?” is becoming just as important as the “what?”

Volland says players are now no longer blindly following the advice of coaches, instead choosing to understand the reasoning behind their instructions.

“Every player is, in fact, quite interested to meet with the fitness trainer to take a look (at the data),” he explains. “You see the averages, you see your own results.”

Over two days club coaches set up a series of circuits designed to measure the individual skill sets of every player.

Balance, strength and endurance tests are at the forefront of the assessment process, with players then sorted into three groups – average or above and below – based on how well they perform.

“It helps you pinpoint what your weaknesses might be,” the 25-year-old says. “It gives you good feedback, in particular on the medical side of things.

“For me, for example, I realized that my balance when I’m on a see-saw board can lack a little – others I did better.”

Testing the Catapult

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As the afternoon sun beats down on the pristine training pitches adjacent to the BayArena, Leverkusen youth team coach Tim Riedel leads out a group of six journalists to test the technology.

Normally accustomed to commanding a group of elite athletes, the panting and wheezing after only two widths of the pitch provides him with an altogether different challenge.

After undergoing a rigorous and draining one-hour session – just a third of the time Leverkusen’s players spend training and the equivalent of their warmup – the data from the GPS tracker is downloaded and portrayed in bar graphs.

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This allows the coaches, but more importantly the players, to easily digest the data and subsequently plan their personalized training and recovery programs.

Unsurprisingly, the performance of Leverkusen’s professionals was often as much as 50% higher than that of the journalists.

Riedel says the players become very competitive when comparing results, which in turn gives them an added incentive to work that much harder.

One of the measured variables is distance covered at high intensity (over 25 km/h), something which the now departed midfielder Kevin Kampl – “the runner of the team,” as Riedel described him – was vastly superior at compared to the rest of his teammates. Kampl joined RB Leipzig on August 31.

Winger Karim Bellarabi, meanwhile, is by far the quickest member of the squad and is able to reach a top speed of 33 km/h.

“It (the data) helps you to see ‘OK, so I need to work harder here’ which you can then utilize when you’re doing some individual training workouts,” Volland says.

“It’s important though not just for the endurance aspect – but also in regards to the recovery.”

Catapult Technology is only used by Leverkusen during training and practice matches, as the Bundesliga uses Opta Sports’ data to analyze player performance during the season.

During one of these training sessions, Leverkusen opened its doors to hundreds of fans in an attempt to galvanize the players ahead of a crucial derby match against local rivals Cologne last season.

Hoards of supporters lined the pathway as the players made their way onto the training pitch, with the electric atmosphere more akin to that of a matchday than a pre-game practice.

Being innovators in technology has helped Leverkusen qualify for European football every year since 2009-10, though numerical data is always prone to throw up an anomaly.

The 2016-17 season was the first time in history that Cologne finished above Leverkusen in the league.

Despite going 2-0 down early in the second half, Leverkusen rallied to level the scores and secure their place in the Bundesliga after a season of teetering precariously on the brink of relegation.

Tactics and nutrition

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Being able to salvage a point from a two-goal deficit isn’t just the work of the players and head coach prowling the touchline.

Behind the scenes there are teams of dedicated tacticians prying over minute details and nutritionists who allow the players’ bodies to cope with 90 intense minutes.

During what in Germany is referred to as an “English Week” – teams playing on Saturday, midweek and Saturday again – the team of video analysts regularly work 12 hours a day.

Their job is to pore over hours of video footage and break it down into understandable chunks for the players and head coach.

Detailed analysis of the day’s match must be completed by that evening, while analysis of another five matches involving the upcoming opponent must be provided ahead of the next fixture.

This intense operation is headed up by Lars Kornetka, Leverkusen’s head of video analysis and assistant coach – the first time the club has combined these two positions.

On a match day, for the first 45 minutes of any match, Kornetka has a maximum of five minutes to relay this information in the dressing room at halftime.

If he has noticed five areas in which the team is under performing, he’ll need to choose the one he deems the most important.

As with their performance in training, different players take a varying amount of interest in the post-game analysis provided by Kornetka and his team.

He admits it is unlikely players will sit at their computer and studiously review the data, so it is up to Kornetka to provide a breakdown the players can quickly consume on their phones, apparently sometimes sat on the toilet.

For the players to put what they have learned into practice on match day, recovery from the previous fixture – in particular with only two days between matches – is vital.

In charge of ensuring the players are fueled for three matches in a week is Anna Lena Boeckel, Leverkusen’s team nutritionist and chef.

Buffets are provided for breakfast, lunch and dinner and always contain fresh, unprocessed foods, fruit and vegetables and, of course, plenty of healthy carbohydrates.

Boeckel says her life is made considerably easier as there are no vegans or vegetarians in the squad, but gluten-free and lactose-free products are provided for those with an intolerance.

Healthy cakes, fruit and homemade protein bars are left in the changing rooms for post and pre-match snacks, as well as halftime refueling.

Some players eat what they are told to, while others, Boeckel explains, take an interest in what to cook and how to cook it, often providing her with updates of meals they make at home.

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‘You still need to have a life’

Catapult Technology isn’t the only company providing data analysis to sports teams. South American company Kizanaro – which provides real-time data analysis – and Prozone – player-tracking software which has been around since 1998 – are also major players in the sector.

Having started in the youth ranks of 1860 Munich, Volland marvels at how the game has developed, in particular over the last few years.

Volland describes the trainers and coaches back then as “from the old school” but recognizes the necessity for footballers to now focus on fitness and technology, meaning today’s youth players have all had the highest possible level of training.

“It just isn’t possible anymore. Now you have to look at your nutrition, at your sleep and how you regulate that,” he says.

“But you still need to have a life.”