Dr Dale Read, Manchester Metropolitan University, expert in how player tracking devices, heart rate monitoring and video analysis is used within team sports, explains how technology is crucial in the battle to win the league.
Friday night marked the start of the 2022-23 Premier League season, and brings to an end weeks of gruelling pre-season training. With a World Cup-affected campaign causing a packed domestic schedule, the importance of data and technology in monitoring performance has never been greater.
Sports science has been at the heart of football for many years now as clubs jostle for the ‘marginal gains’ that will help them beat opponents. A key responsibility of the sport scientist is to monitor the physical performance of the players using technology. And as the new season approaches, this data will become ever more crucial in the battle to win the league – and avoid the dreaded relegation.
Premier League clubs use data to maximise the team’s physical performance and give players the opportunity to best showcase their technical and tactical skills.
The technology that enables us to measure and analyse a player’s physical performance during training has been around for a while – elite Premier League clubs have used GPS tracking for well over a decade, and that’s since filtered down to EFL clubs and even at a semi-pro level now.
But what is relatively new is how these tracking devices can be used during matches. It’s only a couple of years since FIFA permitted footballers to wear GPS devices in matches – those sports bras worn underneath their jerseys contain GPS devices, that are a similar size to a mobile phone.
Long before GPS, you’d have someone with a video camera, but they could only follow one player and then you had to manually digitise them moving around the pitch. Now, we have access to satellites via GPS devices – just like you have on your phone – to pick up where a player is on the pitch, taking measurements ten times a second.
There are a million and one different things you could analyse with data that sport scientists collect, and it is their job to maximise the impact of this data, particularly during this pre-season leading up to what will be an incredibly busy campaign.
For starters, all players will wear a GPS device that monitors how far they run and at what speeds. Backroom staff can use it to monitor their maximum speed, work-to-rest ratio, how often they accelerate/decelerate and much more.
There are a million and one different things you could analyse with data that sport scientists collect, and it is their job to maximise the impact of this data, particularly during this pre-season leading up to what will be an incredibly busy campaign.
For instance, if someone sprints 500 metres during a match, then during the week the coaches might want to replicate or even overload that level of training to help them improve. Next game, they could look to push this to 550 metres of sprinting and to get to a higher level of physical performance. Of course, two matches are never the same and context is king in these situations.
But you can tip athletes over the edge and injure them by doing too much. The technology is there to improve performance but also reduce the risk of injury. Here the heart rate monitor is undervalued. While GPS shows how far and fast a player has run, the heart rate data shows us the physiological cost of that exercise. While some of us might be able to run at the same speed as a Premier League star for a short period of time, their heart rate is likely to be lower, and thus it’s costing them less physiologically.
Good backroom staff will make use of both GPS and heart rate data. But then they’ll also collect information on a player’s wellbeing. They might ask each athlete in the squad every day how they slept last night, how sore or tired they are. You marry that with the other data and you should be able to maximise physical performance while also managing injury risk.
There are many aspects within a game that can’t be controlled by coaches, but they can dictate what happens between matches and maximise the impact of data in this period. For example, if a team has a week to recover and prepare between games, coaches and sports scientists can use the data to help plan when to train, how much to train, what time of day and what drills to do.
There are many aspects within a game that can’t be controlled by coaches, but they can dictate what happens between matches and maximise the impact of data in this period.
Attitudes towards data are changing too. A traditional criticism by sports scientists of head coaches is that they sometimes don’t understand the physical cost of their training on players.
In the past you’d get coaches, especially in pre-season, repeatedly killing the players until they were exhausted. Some coaches would say – ‘well I didn’t need rest when I was a player’. There is a lot to be said for the ‘coach’s eye’, but the data is becoming more and more accepted every year as coaches are appointed who utilised it when they were players.
Players are taking more of an interest too. In years gone by, they might have just thought ‘well, we won on Saturday didn’t we?’ and not care if their running stats were lower than normal. Some players just want to play football – they don’t care for the gym or speed training. But that’s becoming increasingly untenable.
Look at someone like Cristiano Ronaldo, he cares about stats, physical performance data, looking after himself to prolong his career at the highest level. And there’s more and more of those players coming along – because they can’t now just rely on talent. They’ve got to build up their physical performance too.
If I tell a player that they completed 50 sprints in a game, it means little if they were second to the ball every time. We’ve now got software that will overlay the GPS and heart rate data on top of the video analysis. A player or coach will be able to see how one type of sprint, or sprinting in a particular area of the field, was really important because it led to a turnover of possession or a goal.
That could change the way teams set up and players go about their game. It is also extremely impactful for a coach to use this data to convince players that their tactical plans and physical efforts they put in are paying off.
A player or coach will be able to see how one type of sprint, or sprinting in a particular area of the field, was really important because it led to a turnover of possession or a goal. That could change the way teams set up and players go about their game.
Looking into the future, the potential for this information to be used even more by clubs is huge. Sport scientists have historically tended to look at the physical performance in isolation. We haven’t really put it alongside the technical aspects of the game – passing, controlling the ball, heading – or the tactical side, for instance whether the team is playing the high press or sitting deep. This integration will give far more rich data and context into all aspects of the game.
The sports scientist role is evolving too: data analytics is a growing area. There is likely to be a much bigger demand for people who are skilled at understanding, collecting, analysing, visualising and interpreting large data sets.
Big clubs are really investing in this area, and it could yet make the difference as to who wins the Premier League title in the years to come.
