Analysis of the COVID-19 Lockdown Impact on Biological Parameters and Physical Performance in Football Players

The COVID-19 pandemic has caused significant changes in global sustainability, but specifically, this study analyses the impact of lockdown on health and behavior in the game of football. The 2020/2021 Italian football competitive season (indicated as "post-COVID”), taking place following an obliged lockdown and longer than the normal summery season break, was characterized by very short recovery times and was compared to the 2018–2019 "pre-COVID” season, which had a regular course. The comparisons were about anthropometric and hormonal responses, muscle damage, and the physical performance of players in the major league (Serie A), and were made considering two extreme points of the competitive seasons: before the preparatory period (T0) and at the end of the season (T1). Turning to the results, it is significant to note the following: (1) body fat percentage was lower at the start (T0) of the post-COVID season than at the start of the pre-COVID season. During both seasons, serum CK and LDH increased in T1 and were significantly higher in both T0 and T1 of the post-COVID season. (2) Cortisol and testosterone concentrations increased in both seasons from T0 to T1;however, in the post-COVID season, concentrations of both were higher than in the previous season. The testosterone to cortisol ratio increased at the end of the pre-COVID season, whilst strongly decreasing at T1 of the post-COVID season. (3) Blood lactate concentrations significantly decreased during the pre-COVID season but remained unchanged during the post-COVID season. We may conclude that the enforced suspension period and the consequent rapid resumption of all activities influenced the physical and physiological state of professional footballers.

Racial Bias in Fans and Officials: Evidence from the Italian Serie A

Recent scholarship studying the impact of race-based prejudice has emphasized its rampant persistence throughout all aspects of modern society, including the world of sports. Prior research from American leagues has shown that even referees, trained officials intended to enact neutral judgements, are subject to bias against Black and dark-skinned players. To extend these studies and inform policies aimed at combating racial bias in public spaces more broadly, we report results from a unique dataset of over 6500 player-year observations from the Italian Serie A to examine whether these biases persist in European football. Our results show that darker-skinned players receive more foul calls and more cards than lighter-skinned players, controlling for a range of potential confounders and productivity-relevant mediators. By exploiting an absence of fans induced by the COVID-19 pandemic, we also present preliminary evidence that fans may play a key role in inducing poor calls against darker-skinned players. © The Author(s) 2023.

COVID-19 as a Potential Cause of Muscle Injuries in Professional Italian Serie A Soccer Players: A Retrospective Observational Study.

The COVID-19 pandemic has shocked the entire planet. The soccer world has also suffered major upheavals, and many professional soccer players have been infected with the virus. The aim of this study was to evaluate the incidence of injuries in Italian Serie A professional soccer players before and during the COVID-19 pandemic. Methods: We evaluated the incidence of muscle injuries between four competitive seasons of the Italian Serie A (2016-2017, 2017-2018, and 2018-2019 pre-COVID-19 vs. 2020/2021 post-COVID-19) in professional soccer players. Results: Significant differences were found in muscular injuries between the post-COVID-19 season and the previous seasons (p < 0.001). The median split of the players' positivity duration was of 15 days. The players' long positivity (PLP) group showed a significant number of muscular injuries compared to the players' short positivity (PSP) group (p < 0.0014, ES = 0.81, Large). The total teams' days of positivity were significantly related to the total team number of muscular injuries (r = 0.86; CI 95% 0.66 to 0.94; p < 0.0001). In conclusion, this data showed that the competitive season post-COVID-19 lockdown has a higher incidence of muscle injuries in Italian Serie A soccer players compared to the pre-pandemic competitive season.

Biological, Psychological, and Physical Performance Variations in Football Players during the COVID-19 Lockdown: A Prospective Cohort Study.

This prospective cohort study aimed to evaluate whether COVID-19 lockdown caused biological, psychological, and/or physical performance variations in footballers. We compared the 2018/2019 and 2019/2020 seasons evaluating the plasma volume, hematological parameters, iron/ferritin, creatine kinase, vitamin D, cortisol, testosterone, and physiological state of players of the Italian football major league (Serie A). Measurements were performed before the preparatory period (T0), at the beginning (T1) and in the middle (T2) of the championship, and in March (T3) and at the end of season (T4). The results showed that in the 2019/2020 season affected by the lockdown, the weight, BMI, and fat mass percentage were higher than in the previous season. Hematocrit, hemoglobin, red blood cells, and ferritin decreased during both seasons, more significantly than in the regular season. During both seasons, creatine kinase increased from T2 whilst iron concentrations decreased in T3. Testosterone increased in both seasons from T0 to T3 and returned to initial levels at T4; cortisol increased in T2 and T3 during the 2018/2019 season but not during the COVID-19 season. Physical performance tests revealed differences associated with lockdown. Thus, although from a medical point of view, none of the evaluated changes between the two seasons were clinically relevant, training at home during lockdown did not allow the players to maintain the jumping power levels typical of a competitive period.

Impact of COVID-19 lockdown on professional soccer players' match physical activities.

AIM: The COVID-19 pandemic forced the 2019-20 Italian Serie A competition to stop and players went into lockdown. During lockdown, players only trained at home, likely having a detrimental effect on players' physical fitness and capacity. This study investigated the effect of the COVID-19 lockdown on professional soccer players' match physical activities. METHODS: Match activities of 265 male professional soccer players were assessed in two periods prior to (PRE1 and PRE2) and one period following the lockdown (POST) using a video tracking system. Linear mixed models were used to examine differences between-periods in total (TD), very high-speed (VHS), sprint (SPR), high-acceleration (ACC) and high-deceleration (DEC) distances, considering full match data and data from six 15-min intervals. RESULTS: TD and VHS during POST were lower than the two other competitive periods (p < 0.001, d small-moderate). SPR did not show differences between periods (p > 0.636). ACC and DEC during POST were lower than PRE2 (p < 0.015, d small). Declines in most 15-min intervals after lockdown were observed in TD and VHS. CONCLUSIONS: There were small differences in the temporal distribution of SPR, ACC and DEC at POST. After the COVID-19 lockdown, soccer players' higher-intensity running activities were similar to those of games played before the lockdown, but TD and VHS decreased, both considering the entire match and 15-min intervals. The temporal distribution of running activities was mostly stable throughout the season.