Jump as a Fatigue Indicator
The monitoring of neuromuscular fatigue in athletes is very relevant when planning training sessions and competitions.
Globalization –the process driven by the increase in cross-border flows of goods, services, money, people, information and culture1– has dramatically affected western societies and football is not isolated from this phenomenon. The free circulation of players has increased substantially during the last 25 years, because the limit of foreign players in the European leagues has been banned or more permissive as well as clubs developing more of a entrepreneurial mentality.2
According to the CIES Football Observatory data, 3 the percentage of foreign players in the main 31 European leagues increased to a record 41.8% in 2019, while 10 years before the percentage was 34.7% (Figure 1). Likewise, the percentage of players trained in the club itself has decreased notoriously in the period 2009-2019: 10 years ago the percentage was 23.2%, and in 2019 it was 17.2% (Figure 2).
In 2018, there were 13,383 expatriate football players for the 2120 clubs which compete in 152 leagues of 98 national associations around the world4. On average, a team has 5.7 expatriate football players, which means that foreign players represent 21.4% of the team members. If we only consider the clubs that play in the UEFA confederation, the percentage reaches 26.0%. This shows the importance of foreign players in their respective teams is increasingly higher. The percentage of minutes played by the expatriate football players is 64.7% in the Premier League, 61% in the Serie A, 51.5% in the Bundesliga, 39% in La Liga, and 37.3% in the Ligue 1.
A recent research5 has analyzed the relationship between the migration of players and the annual ranking of the national teams of each country according to the World Football Elo Rating. The study, published in the magazine Frontiers in Psychology in 2019, was based on the annual analysis of 243 countries in the period 1994-2018. The migration was measured collecting the number of emigrant players from each country that played in some of the following competitions: Spanish La Liga, Italian Serie A, English Premier League, German Bundesliga, and the French Ligue 1 (all together known as the “Big-Five”). The results showed that the outstanding performance of a national team in a championship causes a high number of players from this country to immediately migrate to another competition with a higher football level. The best football players are quickly signed by wealthy clubs. However, the impact of the players from the national team that emigrate, doesn’t have such a big impact and it isn’t that fast. The positive impact of these emigrant players for the position of their national team in the World Football Elo Rating takes place 4 years after their departure to another country.
It seems that the future of football is attached to an increasing globalization phenomenon. Player migration is becoming a key aspect to explain the performance of the teams. The data indicates that having players trained in home clubs is becoming less important. The challenge for the teams may be to combine both strategies: support training good players in the home club and reinforce the team with football players from other clubs when their own players aren’t that good for a given position.
Carlos Lago Peñas
1 Held, D., McGrew, A., Goldblatt, D., and Perraton, J. (1999). Global Transformations. Politics, Economics, and Culture. Oxford: Polity Press
2 Milanovic, B. (2005). Globalization and goals: does soccer show the way? Rev. Int. Polit. Econ. 12, 829–850. doi: 10.1080/09692290500339818
3 Poli, R., Ravenel, L., and Besson, R. (2019). The demographics of football in the European labour market. Avaliable at: http://www.football-observatory.com/IMG/sites/mr/mr49/en/
4 Poli, R., Ravenel, L., and Besson, R. (2019). World football expatriate: global study 2019. Avaliable at: http://www.football-observatory.com/IMG/sites/mr/mr45/en/
5 Lago-Peñas C, Lago-Peñas S and Lago I (2019) Player Migration and Soccer Performance. Front. Psychol. 10:616. doi: 10.3389/fpsyg.2019.00616
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.