Jump as a Fatigue Indicator
The monitoring of neuromuscular fatigue in athletes is very relevant when planning training sessions and competitions.
The arrival of Johan Cruyff as FC Barcelona’s coach in 1988 caused a revolution in the way the game is understood and footballers are trained. One of his best-remembered comments was that: “All coaches talk about movement, about running a lot. I don’t think players need to run that much. Football is a game that’s played with the brain. You have to be in the right place at the right time, not too early and not too late”.1 His focus on possession of the ball and the use of space and superiority in numbers reduced the importance of physical performance in the game. In another quote, he noted: “My forwards should only run 15 metres”.
Scientific research seems to prove him right. A recent publication2 analysed how ball possession influences physical performance in high-level players. The study, published in Science and Medicine in Football in 2020, was based on an analysis of the 380 games played in the Spanish LaLiga in the 2018-2019 season. In total, it examined the competitive behaviour of 412 players who played the full ninety minutes to obtain 8,468 observations. The footballers were classified into 5 different positions: Central Defenders (CD, number of observations = 2,452), Full Backs (FB, number of observations = 1,822), Defensive Midfielders (DM, number of observations = 2,022), Attacking Midfielders (AM, number of observations = 1,020) and Forwards (FW, number of observations = 1,152). Physical performance was analysed considering the following categories: total distance covered, low intensity running (0–14.0 km/h), medium intensity running (14.1–21.0 km/h), high intensity running (21.0 km/h), very high intensity running (21.1–24.0 km/h) and sprint (>24.0 km/h). All these variables were calculated taking into account the actual playing time and were normalised to metres per minute. Actual playing time refers to the duration of the match after deducting the time used for stoppages, substitutions, goals and injuries, in other words, time when the ball is not in play. A cluster analysis divided the teams into four categories based on the percentage of possession they had in each game: teams with very low possession (35.2 ± 4.2% ball possession, with a range of 20.7 –40.3%, n=1648), teams with low possession (45.5 ± 2.8% ball possession, with a range of 40.4–50.0%, n=2594), teams with high possession (54.5 ± 2.8% ball possession, with a range of 50.1–59.7%, n=2589) and teams with very high possession (64.9 ± 4.2% ball possession, with a range of 59.8–79.3%, n=1637). Physical performance was recorded using the TRACAB tracking system used by Mediacoach.
The results suggest some remarkable conclusions:
These results are described in the Figure below.
Although these results should be viewed with caution due to the complex nature of football, they can help coaches to better understand the physical demands of the game and to develop models that can predict the physical performance of players depending on the kind of football played by each team. Having the ball is the most important thing in football.
Carlos Lago Peñas
2 Lorenzo-Martínez, M.; Kalén, A.; Rey, E.; López-Del Campo, R.; Resta, R. & Lago-Peñas, C. (2020). Do elite soccer players cover less distance when their team spent more time in possession of the ball? Science and Medicine in Football, ahead of print. (https://www.tandfonline.com/doi/abs/10.1080/24733938.2020.1853211?journalCode=rsmf20).
Although there are several studies on this topic, many of them have analyzed these demands by looking at just a few variables or using very broad timeframes. A new study completed by physical trainers from F.C. Barcelona has analyzed several of these details more closely.
The understanding of the modifying variables of the game, based on the degrees of freedom.
Training using eccentric exercises is important to prevent possible damage. However, intensive training can also cause muscle damage, so it is critical to be vigilant in order to keep injury risk to an absolute minimum.
The importance of building a game model in football.
Cardiovascular endurance manifests as a moderator of the load result to which the athlete is exposed.