FSI Football Science Update

The effect of physical fatigue on the performance of soccer players: A systematic review.

Dambroz F, Clemente FM, Teoldo I.

PLoS One. 2022 Jul 14;17(7):e0270099. doi: 10.1371/journal.pone.0270099.

This systematic review on a total of 12 articles about the effect of physical fatigue on the performance of soccer players from any age group, competitive level or sex found that the studies on cognitive performance have shown divergent results; that there are negative on the technical performance of the pass, dribble and kick; and that studies have shown a reduction in sprint capacity and distances covered at high velocity. Finally, the only study that analyzed the tactical performance in the field showed an increase in the team’s collective tactical behavior but did not include analysis of the players’ individual tactical actions.



Carbohydrate fear, skinfold targets and body image issues: A qualitative analysis of player and stakeholder perceptions of the nutrition culture within elite female soccer.

McHaffie SJ, Langan-Evans C, Morehen JC, Strauss JA, Areta JL, Rosimus C, Evans M, Elliott-Sale KJ, Cronin CJ, Morton JP.

Sci Med Footb. 2022 Jul 14. doi: 10.1080/24733938.2022.2101143.

This qualitative study used semi-structured interviews with 47 participants, including elite female soccer players and their parents, coaches, sport scientists, nutritionists and medical staff. Data demonstrate that players tend to “under-fuel”, which is likely caused by misunderstandings about the impact of carbohydrate intake on body composition, a fear of weight gain and the associated impacts upon body image arising from social media, key stakeholders (e.g., coaches) and the skinfold culture surrounding measurement of body composition. Such cultural issues are amplified by the lack of infrastructure supporting the women’s game (e.g. staffing resource, on-site food provision, player education programmes etc.) that was considered incomparable to the men’s game.



Substitutions in football – what coaches think and what coaches do.

Wittkugel J, Memmert D, Wunderlich F.

J Sports Sci. 2022 Jul 13:1-10. doi: 10.1080/02640414.2022.2099177.

This paper presents two studies investigating substitutions in football: Study I, a survey reporting the opinions of 73 licensed coaches, and Study II, data-based analysis of a total of 41,301 substitutions from 7,230 matches in seasons 2014/15 to 2018/19 of the top four European football leagues. In Study I the coaches stated to prefer offensive substitutions over defensive substitutions and additionally indicated that changing the current score was more likely to be a reason for substitution than keeping the score. However, the Study II revealed that not offensive, but neutral substitutions, where the player is replaced by a player of the same playing position, were most frequent, and that offensive players were more frequently replaced. In addition, more than half of the defensive substitutions were made while winning with the objective of keeping the result, while more than half of the offensive substitutions were made while losing.



Cultural similarity and impartiality on voting bias: The case of FIFA’s World’s Best Male Football Player Award.

Johnson MR, McCarthy IP.

PLoS One. 2022 Jul 13;17(7):e0270546. doi: 10.1371/journal.pone.0270546.

This study evaluated the cultural similarity voting bias for the Best FIFA Men’s Player Award, according to cultural similarity factors (cultural distance, cultural clusters, and collectivism), in-group factors (nationality, club, league, geography, ethnicity, religion, and language) and the impartiality of the voter’s country, finding cultural similarity is associated with voting bias, with media voters less biased than coaches, and coaches less biased than captains.



Reduced performance after return to competition in ACL injuries: an analysis on return to competition in the ‘ACL registry in German Football’.

Szymski D, Achenbach L, Weber J, Huber L, Memmel C, Kerschbaum M, Alt V, Krutsch W.

Knee Surg Sports Traumatol Arthrosc. 2022 Jul 10. doi: 10.1007/s00167-022-07062-8.

This study analyzed the ‘ACL registry in German Football’ between 2014 and 2018 in professional (1st-3rd league), semi-professional (4th-6th league) and amateur leagues (7th league). A total of 607 ACL injuries were registered with a mean RTC time of 337.1 days. After primary ACL ruptures, the fastest RTC was found in professional football (247.3 days), while in semi-professional (333.5 d) and amateur football (376.2 d) a prolonged absence was detected. Re-ruptures occurred in 17.8% of the players. Within the first three seasons after injury, 20% of professional players and 36.7% of semi-professional had to end their career and keeping the level of play was only possible for 47.5% of professionals, 29.6% of semi-professionals and 28.1%) of amateurs.



Do players competing in the UEFA Champions League maintain running performance until the end of the match? Positional analysis between halves and 5-minute intervals.

Kołodziejczyk M, Chmura P, Modric T, Versic S, Andrzejewski M, Chmura J, Sekulic D, Rokita A, Konefał M.

J Sports Med Phys Fitness. 2022 Jul 11. doi: 10.23736/S0022-4707.22.14069-7.

This investigation on 179 soccer players during 20 UEFA Champions League (UCL) 2020/2021 group stage matches with the InStat Fitness semi-automatic video system found that all soccer positions achieved significantly higher average speed in the first half of the match than in the second half. In all 5-minute intervals Central Midfielders covered more total distance than Central Defenders, Wide Midfielders performed more high-intensity running than Central Defenders and Forwards performed more high-intensity running than all other playing positions.



The effect of pre-match sexual intercourse on football players’ performance: a prospective cross over study.

Peleg-Sagy T, Zeller L, Perelman Y, Bortnik L, Maman T, Sagy I.

J Sports Med Phys Fitness. 2022 Jul 11. doi: 10.23736/S0022-4707.22.14022-3.

Current research suggests that pre-competition sexual intercourse does not influence athletes’ performance. Yet, high-quality studies in this field are scarce. This prospective crossover study using post-game telephone interviews on 14 players of a team of the Israeli Football Premier League during the 2018-19 season identified sexual intercourses the night before the match in nine cases, in which the average speed during the match was significantly slower (6.5 vs. 6.0 Km/h).



Impact of technical and physical performance on match outcome over five elite European soccer seasons.

Morgans R, Orme P, DI Michele R.

J Sports Med Phys Fitness. 2022 Jul 11. doi: 10.23736/S0022-4707.22.14018-1.

This study using an optical tracking system in 1186 matches played in the Russian Premier League during the 2017 to the 2021 seasons found that shots on target and duels won were higher in won vs. drawn and lost matches. Sprint distance, counterattacks, shots, interceptions, recoveries, and successful tackles all showed small though significant favourable relationships with match outcomes, with crosses showing an opposite effect.



A complete season with attendance restrictions confirms the relevant contribution of spectators to home advantage and referee bias in association football.

Sors F, Grassi M, Agostini T, Murgia M.

PeerJ. 2022 Jul 4;10:e13681. doi: 10.7717/peerj.13681.

This study on 3,898 matches from the first and second divisions of the UEFA top five ranked countries England, Spain, Italy, Germany, and France on the pandemic 2020-21 season found fewer home victories and more away victories than the previous five complete seasons with spectators, with 54.95% of home points compared with 59.36% for the previous seasons. As no referee bias in terms of fouls, yellow cards, red cards, penalty kicks and extra time was observed, it can be concluded that the absence of spectators significantly reduced the home advantage but that a slight home advantage persisted in the 2020-21 season probably due to other factors, namely, learning and travel, according to the model by Courneya & Carron (1992).