Return to football training and competition after lockdown caused by the COVID-19 pandemic: medical recommendations

Wrestling injuries during the 2016 Rio and 2020 Tokyo Olympic Games

OBJECTIVES

To evaluate and compare the injuries of Olympic wrestlers during the 2016 Rio and 2020 Tokyo Olympic Games held in August 2021 due to the COVID-19 pandemic.

METHODS

In this descriptive epidemiological study, injury report forms were used to collect and analyse injury data during the competitions.

RESULTS

During 410 matches in the Rio Olympic Games, 21 injuries were recorded among 346 wrestlers (112=women), a rate of 5.1 injuries/100 bouts and 6.1 injuries/100 athletes. During 322 matches in the Tokyo Olympic Games, 28 injuries were recorded among 287 wrestlers (96=women), with 8.7 injuries/100 bouts and 9.8 injuries/100 athletes. However, these apparent differences in injury rates between Tokyo and Rio were not statistically significant (injuries/bout: p=0.057, 95% CI: 0.31 to 1.02; injuries/athlete: p=0.087, 95% CI: 0.33 to 1.08). Mild injuries comprised the greatest proportion of injuries in both Olympic Games. Severe injuries accounted for 0%, 16.7% and 36.4% of injuries in Greco-Roman, Freestyle and Women's wrestling, respectively.

CONCLUSION

Most wrestling injuries in the 2016 Rio and 2020 Tokyo Olympic Games were mild skin injuries in the head and face regions due to direct body contact during standing positions in the 1/8-final round of wrestling competitions. No critical injury was observed during the recent Olympic Games. Attention should be drawn to preventing upper limb joint dislocations as common severe injuries in both Olympic Games. While not statistically significant, the Tokyo Games, after the COVID-19 pandemic, witnessed a higher injury occurrence than the Rio Games.

Epidemiology of Injury and Illness in North American Professional Men's Soccer: Comparing COVID-19 Lockdown With Previous Seasons

BACKGROUND

After COVID-19 lockdown, studies across Europe and Asia examined its effect on professional soccer injury rates and severity; however, COVID-19 lockdown influence on injuries in United States men's professional soccer has not been evaluated.

HYPOTHESIS

Injury and illness rates during the 2020 season were higher than the previous 2 seasons.

STUDY DESIGN

Retrospective observational cohort study.

LEVEL OF EVIDENCE

Level 3.

METHODS

Medical staff from participating Major League Soccer (MLS) clubs entered injuries and athletic exposures during the study period into a league-wide electronic medical record system. Injury rate and severity were analyzed to examine differentials between the 2020 COVID season and historical controls.

RESULTS

The injury incidence rate per 1000 hours in 2020 was 10.8, ie, higher than 2018 (5.4) and 2019 (5.0) (P < 0.05). Training injury incidence rate increased in 2020 (8.9) compared with 2018 (2.5) and 2019 (2.6) (P < 0.05), whereas match injury incidence decreased in 2020 (18.3) compared with 2018 (24.0) and 2019 (22.7) (P < 0.05). Incidence rates of lower extremity muscle injuries (6.04), anterior cruciate ligament (ACL) injuries (0.17), and concussions (0.49) were also higher in 2020 compared with 2018 (2.5, 0.07, 0.27) and 2019 (2.36, 0.05, 0.22) (P < 0.05). More injured players in 2020 missed >90 days (17.7%) than in 2018 (10.2%) and 2019 (10.1%) (P < 0.05). Incidence of all non-COVID-19 illness was higher in 2020 (3.93) than 2018 (1.53) and 2019 (1.32) (P < 0.05).

CONCLUSIONS

During 2020, there were significant increases in incidence rates of overall injuries, training injuries, lower extremity muscular injuries, ACL injuries, concussions, and non-COVID illness, along with a higher percentage of players missing >90 days compared with the 2 previous seasons.

CLINICAL RELEVANCE

These results may help clarify the effects of future MLS inseason work stoppages and periods of restricted training.

The Surgical Management of NCAA Division 1 College Football Injuries Post COVID-19: A Single Institution Retrospective Review

ABSTRACT

Cohen, JL, Cade, WH, Harrah, TC, Costello II, JP, and Kaplan, LD. The surgical management of NCAA Division 1 college football injuries post COVID-19: A single institution retrospective review. J Strength Cond Res 38(5): 906-911, 2024-The unprecedented COVID-19 pandemic had a significant impact on college football operations, including athletes' training regimens. As a result of these changes, concern for increased injury susceptibility post COVID-19 regulations has become a point of discussion. The current study sought to evaluate the incidence of surgical injury among NCAA Division 1 college football players at the authors' institution during the first full season after start of the COVID-19 pandemic compared with previous years. Retrospective chart review was performed for all players who sustained injuries requiring surgery while a member of the NCAA Division 1 football program during the 2009-2021 seasons. A p -value of ≤0.05 was used to determine significance. A total of 23 surgical injuries occurred in 22 players during the 2021 season compared with 121 in 118 players in the 12 previous seasons combined ( p = 0.0178; RR = 1.47). There was a significant increase in shoulder injuries ( n = 13 vs. n = 31; p = <0.0001; RR = 3.05) and specifically a significant increase in labral tears ( n = 10 vs. n = 30; p = 0.0003; RR = 2.74). No difference was seen in knee injuries ( n = 10 vs. n = 77; p = 0.27; RR = 1.35) and specifically no difference in anterior cruciate ligament injuries ( n = 3 vs. n = 31; p = 0.77; RR = 1.17). This phenomenon is multifactorial in nature, but alterations to players' training and preparations because of the COVID-19 pandemic likely resulted in suboptimal conditioning, leading to the increased incidence of surgical injuries emphasizing the importance of adequate strength training and conditioning.

Impact of COVID-19 on football attacking players' match technical performance: a longitudinal study

This study examined the impact of COVID-19 on 28 indicators of match technical performance (MTP) for football attacking players upon their return to play. Analyzing data from 100 players in the Big Five European football leagues, covering 1500 matches each before and after COVID-19 over 3 years (2020-2023), revealed significant differences in 76% of players' MTP indicators. Notably, 14 indicators, particularly the five indicators linked to scoring, significantly decreased post-COVID-19. On average, players needed 3.09 matches to regain pre-infection MTP levels. The impact varied across player groups, with those in the elite group showing a milder effect; they required an average of 2.64 matches for recovery, compared to the control group's 3.55 matches. We found that, with increasing age, the majority of players' MTP indicators did not exhibit significant changes, both before and after they contracted COVID-19. In conclusion, the study highlighted the negative impact of COVID-19 on football attacking players' MTP. Players in the elite group experienced fewer adverse effects than those in the control group. This insight assisted coaches and managers in evaluating the impact of COVID-19 and similar virus-induced illnesses on players' MTP, enabling them to formulate training regimens for recovery and specific match tactics upon players' return to play.

The impact of COVID-19 on national hockey league players' return to play

OBJECTIVE

Evaluate the on-ice performance and return to play (RTP) rate following COVID-19 for National Hockey League (NHL) players during the 2020-21 season.

METHODS

Players with COVID-19 during the abbreviated 2020-21 season were identified using publicly accessible online sources. Demographics and on-ice metrics were accessed using the NHL's online statistics website. The length of time, rate of RTP, and games missed due to COVID-19 were analyzed. Primary outcomes included average time on ice (TOI) per game (TOI/G), average TOI per shift (TOI/S), and points per game (PPG) compared at different timepoints including pre- and post-COVID-19.

RESULTS

A total of 73 players (47 forwards, 18 defensemen, 8 goalies) had a documented COVID-19 diagnosis during the abbreviated 2020-21 season. Players missed an average of 5.6 games (14.7 days) due to COVID-19. The post-COVID-19 RTP rate was 97.3%, including playoffs. No differences were found in TOI/G between the pre- (15.7 ± 3.9 min) and post-COVID-19 (15.8 ± 3.4 min, p = 0.874) or in the first (15.8 ± 4.0 min) and second week (15.9 ± 3.8 min, p = 0.925) returned. TOI/shift did not change from pre- (45.6 ± 5.3 sec) to post-COVID-19 (46.7 ± 4.6 sec, p = 0.035) or in first (46.2 ± 5.4 sec) and second week post-COVID-19 (46.2 ± 4.8 sec, p = .854). No differences were identified for PPG between career, pre-COVID-19, and post-COVID-19 (0.44 vs 0.38 vs 0.41; p = 0.274).

CONCLUSION

RTP post-COVID was markedly high for NHL players. While the effects of COVID-19 on specific physiological measures remains to be elucidated, this study found NHL players do not have reduced performance following COVID-19.

Academic and healthcare efforts from Cessation to complete resumption of professional football tournaments during COVID-19 pandemic: A narrative review

The Coronavirus disease 2019 (COVID-19) caused by the SARS-CoV-2 virus led to over 626 million infections and 6.5 million deaths worldwide and forced to cancel or postpone several sporting events. Effective control techniques are therefore urgently required to avoid COVID-19 spread at these local and global events. This narrative review addressed the healthcare and research efforts on the intersections between COVID-19 and major professional sports leagues worldwide, with special reference to the FIFA World Cup football 2022. This explained how the broader transformation of COVID-19 from being a potential risk to an urgent pandemic public health emergency, caused the world of Football to halt between February and March 2020. This review could add to the growing literature on the importance of scientific research in understanding the relationship between mass sports events and COVID-19 trajectory, concerning studies conducted globally and particularly for the recommencement of major professional football competitions. The information outlined in the article may help sports organizations understand the risks associated with sports and their settings and improve their preparedness for future events under unprecedented circumstances. There were tremendous global healthcare and research efforts to deal with this unprecedented pandemic. The successful FIFA World Cup football tournament was an indicator of the success of these efforts.

Clinical and Biochemical Implications of Hyaluronic Acid in Musculoskeletal Rehabilitation: A Comprehensive Review

Hyaluronic acid (HA) naturally occurs as a biopolymer in the human body, primarily in connective tissues like joints and skin. Functioning as a vital element of synovial fluid, it lubricates joints, facilitating fluid movement and diminishing bone friction to protect articular well-being. Its distinctive attributes encompass notable viscosity and water retention capacities, ensuring flexibility and absorbing shock during motion. Furthermore, HA has gained significant attention for its potential benefits in various medical applications, including rehabilitation. Ongoing research explores its properties and functions, especially its biomedical applications in several clinical trials, with a focus on its role in improving rehabilitation outcomes. But the clinical and biochemical implications of HA in musculoskeletal rehabilitation have yet to be fully explored. This review thoroughly investigates the properties and functions of HA while highlighting its biomedical applications in different clinical trials, with a special emphasis on its role in rehabilitation. The presented findings provide evidence that HA, as a natural substance, enhances the outcomes of musculoskeletal rehabilitation through its exceptional mechanical and biochemical effects.

Epidemiology of injuries in elite Women's Artistic Gymnastics: a retrospective analysis of six seasons

Background

Women's Artistic Gymnastics (WAG) is a sport well known for requiring a heavy and difficult training load from a younger age to reach a high level of performance. This also is associated with an injury risk. Epidemiological studies are thus needed to improve injury prevention strategies.

Objective

We aimed to determine the injury epidemiology in French high-level WAG.

Methods

We conducted a retrospective analysis of injury data collected prospectively over six seasons from the 2014-2015 season to the 2019-2020 season among French high-level Women's Artistic Gymnasts from the France Gymnastics National Centre of Saint-Etienne. We performed descriptive analyses, including the calculation of the 1-year injury prevalence.

Results

43 gymnasts were included in this study, representing 111 gymnast-seasons. A total of 285 injuries were collected over the study period, that was, an average of 2.6 injuries per gymnast per season. On average, 91.4% of gymnasts had at least one injury per season. The estimated injury incidence rate was 1.8 injuries per 1000 hours of gymnastics practice. The knee was the most affected joint (16%), followed by the elbow (12%) and the ankle (12%). The most frequent injury type was physis pathologies (16%) and bone injuries (15%). Eighty-eight per cent of injuries required a modification of the gymnastics practice.

Conclusions

The results of this study allowed a description of the epidemiology of injuries in this population of young and elite gymnasts. This very high injury prevalence supports the need to improve injury risk reduction strategies in WAG.

Soccer's AI transformation: deep learning's analysis of soccer's pandemic research evolution

Introduction

This paper aims to identify and compare changes in trends and research interests in soccer articles from before and during the COVID-19 pandemic.

Methods

We compared research interests and trends in soccer-related journal articles published before COVID-19 (2018-2020) and during the COVID-19 pandemic (2021-2022) using Bidirectional Encoder Representations from Transformers (BERT) topic modeling.

Results

In both periods, we categorized the social sciences into psychology, sociology, business, and technology, with some interdisciplinary research topics identified, and we identified changes during the COVID-19 pandemic period, including a new approach to home advantage. Furthermore, Sports science and sports medicine had a vast array of subject areas and topics, but some similar themes emerged in both periods and found changes before and during COVID-19. These changes can be broadly categorized into (a) Social Sciences and Technology; (b) Performance training approaches; (c) injury part of body. With training topics being more prominent than match performance during the pandemic; and changes within injuries, with the lower limbs becoming more prominent than the head during the pandemic.

Conclusion

Now that the pandemic has ended, soccer environments and routines have returned to pre-pandemic levels, but the environment that have changed during the pandemic provide an opportunity for researchers and practitioners in the field of soccer to detect post-pandemic changes and identify trends and future directions for research.

Injury Rates at an NCAA Division I Institution After the COVID-19 Lockdown: A Descriptive Epidemiological Study

Background

The coronavirus 2019 (COVID-19) pandemic led to frequent schedule changes, abbreviated seasons, and disrupted training at all levels of organized sports.

Purpose/Hypothesis

The purpose of this study was to investigate the epidemiology of sports-related injuries at a single National Collegiate Athletic Association (NCAA) Division I institution during the 2020 COVID lockdown season when compared with pre-COVID seasons. It was hypothesized that there would be an increase in the overall injury rate and an increase in the number of days missed because of injury during the 2020 season when compared with the previous seasons.

Study Design

Descriptive epidemiology study.

Methods

The injury surveillance database at a single NCAA Division I institution was queried for injuries that resulted in time loss (missed game or practice) for a student-athlete or for injuries that persisted >3 days. Injuries were categorized by anatomic area. Days unavailable because of injury were recorded as total days that a student-athlete was listed as "out of activity." Injury incidence and days unavailable, per 1000 athlete-exposures (AEs), were calculated for 3 pre-COVID seasons (2017-2019) and the 2020 season. The authors calculated the injury rate ratio (IRR) and its associated 95% CI of the 2020 season in comparison with those for the pre-COVID seasons.

Results

Compared with the pre-COVID seasons, the total injury incidence increased by 10.5% in the 2020 season (68.45 vs 75.65 injuries/1000 AEs; IRR, 1.11 [95% CI, 1.08-1.13]). Total days unavailable decreased by 20.7% in the 2020 season (1374 vs 1089 days/1000 AEs; IRR, 0.79 [95% CI, 0.77-2.26]). Compared with women's teams, men's teams had a larger increase in total injury incidence (16.4% vs 6.5%) and larger decrease in days unavailable (23.7% vs 10.75%). There were no clear trends to changes in anatomic distribution of injuries, either by sport or between the sexes.

Conclusion

Compared with the pre-COVID seasons, the injury incidence was higher and the number of days missed because of injury lower among collegiate student-athletes at a single NCAA Division I school in the season immediately after the COVID-19 lockdown.

Bone Stress Injuries at the Ankle and Foot

Bone stress injuries (BSIs) are a frequent finding in athletes, particularly of the foot and ankle. A BSI is caused by recurring microtrauma to the cortical or trabecular bone exceeding the repair capacity of normal bone. The most frequent fractures at the ankle are low risk, characterized by a low risk for nonunion. These include the posteromedial tibia, the calcaneus, and the metatarsal diaphysis. High-risk stress fractures have a higher risk for nonunion and need more aggressive treatment. Examples are the medial malleolus, navicular bone, and the base of the second and fifth metatarsal bone.Imaging features depend on the primary involvement of cortical versus trabecular bone. Conventional radiographs may remain normal up to 2 to 3 weeks. For cortical bone, early signs of BSIs are a periosteal reaction or the "gray cortex sign," followed by cortical thickening and fracture line depiction. In trabecular bone, a sclerotic dense line may be seen. Magnetic resonance imaging enables early detection of BSIs and can differentiate between a stress reaction and a fracture. We review typical anamnestic/clinical findings, epidemiology and risk factors, imaging characteristics, and findings at typical locations of BSIs at the foot and ankle that may help guide treatment strategy and patient recovery.

Achilles Tendon Repair after Tenorraphy Imaging and the Doughnut Metaphor

After Achilles tendon tenorraphy, tendon tissue undergoes a long period of biological healing. During this period, tissue turnover shows heterogeneity between its peripheral and central regions. This case report concerns the description of the tendon healing process of an athlete who underwent an Achilles tendon tenorraphy. As the reparative processes progressed, magnetic resonance imaging (MRI) showed centralization of the hyperintensity area and the tendon assumed a doughnut-like appearance. At the same time, ultrasound (US) assessment showed a progressive reorganization of the tendon fibrillar structure. Therefore, for the athlete, MRI and US assessment together represent a useful tool for the decision-making process after Achilles tendon tenorraphy.

Are Football Players More Prone to Muscle Injury after COVID-19 Infection? The "Italian Injury Study" during the Serie a Championship

INTRODUCTION

Football was the first sport to resume competitions after the coronavirus disease 2019 (COVID-19) lockdown and promptly the hypothesis was raised of a potential relationship between the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and musculoskeletal injuries in athletes. This study aimed to confirm the association between SARS-CoV-2 infection and muscle strain injury in a large population of elite football players and to investigate if the COVID-19 severity level could affect the risk of injury.

METHODS

A retrospective cohort study involving 15 Italian professional male football teams was performed during the Italian Serie A 2020-2021 season. Injuries and SARS-CoV-2 positivity data were collected by team doctors through an online database.

RESULTS

Of the 433 included players, we observed 173 SARS-CoV-2 infections and 332 indirect muscle strains. COVID-19 episodes mostly belonged to severity level I and II. The injury risk significantly increased after a COVID-19 event, by 36% (HR = 1.36, CI_95% 1.05; 1.77, p-value = 0.02). The injury burden demonstrated an 86% increase (ratio = 1.86, CI_95% 1.21; 2.86, p-value = 0.005) in the COVID-19 severity level II/III versus players without a previous SARS-CoV-2 infection, while level I (asymptomatic) patients showed a similar average burden (ratio = 0.92, CI_95% 0.54; 1.58, p-value = 0.77). A significantly higher proportion of muscle-tendon junction injuries (40.6% vs. 27.1%, difference = 13.5%, CI_95% 0.002%; 26.9%, p-value = 0.047) was found when comparing level II/III versus Non-COVID-19.

CONCLUSIONS

This study confirms the correlation between SARS-CoV-2 infection and indirect muscle injuries and highlights how the severity of the infection would represent an additional risk factor.

Impact of the COVID-19 Pandemic on Injury Incidence in Japanese Male Professional Soccer Players

Background

The outbreak of the 2019 novel coronavirus disease (COVID-19) led to an enforced quarantine period and limited training and match activities for athletes.

Purpose

To report the influence of the COVID-19 pandemic on the occurrence of injury in Japanese male professional soccer players.

Study Design

Descriptive epidemiology study.

Methods

In total, 21 clubs in the 2019 season and 28 clubs in the 2020 season from the Japan Professional Football League were prospectively followed, and 16 clubs in 2019 and 24 clubs in 2020 were analyzed in this study. Individual training, match exposure, and time-loss injuries were recorded using an electronic data capture system. The influence of COVID-19-related suspension during the 2020 season was retrospectively investigated via comparisons with the 2019 season.

Results

Total activity time included 114,001 hours in training and 16,339 hours in matches in 2019 and 170,798 hours in training and 25,411 hours in matches in 2020. The mean training interruption period caused by COVID-19 in 2020 was 39.9 days (range, 3-65 days), and the mean game-interruption period was 70.1 days (range, 58-79 days). The total number of injuries was 1495 in 2019 and 1701 in 2020. The overall injury incidence per 1000 hours of exposure was 5.7 in 2019 and 5.8 in 2020. The overall injury burden per 1000 hours of exposure was 155.5 days in 2019 and 130.2 days in 2020. The muscle injury incidence was highest in May 2020, immediately after the suspension period.

Conclusion

The overall injury incidence did not differ between 2019 and 2020. However, muscle injury incidence notably increased in the 2 months after the COVID-19 pandemic suspension period.

A Study on the Injury Rate of Spanish Competitive Athletes as a Consequence of the COVID-19 Pandemic Lockdown

The COVID-19 lockdown may have had collateral effects on the conditions of athletes, with possible increases in injury risks upon the return to sports. Due to the existence of multiple factors of injury risks based on the lockdown and the return to sports, the aim of this study was to analyze the injury rates after the lockdown in competitive athletes. A non-experimental quantitative design based on a survey was carried out, and 94 athletes (42 males and 52 females; 23.57 ± 6.20 years) participated. Statistical analyses were carried out using non-parametric tests. Injury rates did not increase significantly after the lockdown, and there were no statistical differences between performance levels, types of sports, the design of a specific training program by sports professionals during the lockdown, the moment of injury, and the mechanism of injury. It is important to develop injury prevention protocols to prepare athletes after such a long period of detraining.

Bio-secure bubble during the COVID-19 pandemic to host the Asian Football Confederation (AFC) Champions League: A retrospective observational study

Background and Aims

To describe the COVID-19 positivity rate among football players, team staff, and local organizing committee members participated in the Asian Football Confederation (AFC) Champions League (West) tournament organized with the Bio-secure bubble protocol in place.

Methods

A retrospective observational study was carried out to include a total of 2184 participants during the AFC-West tournament in Qatar, which was a 3-week event (September 14-October 3, 2020). This event was undertaken under the Bio-secure bubble protocol, which was developed and implemented for sports events in Qatar during the pandemic. Within 72 h of departure and upon arrival in Qatar, all participants underwent reverse-transcriptase polymerase chain reaction testing (RT-PCR) to diagnose COVID-19. The test was considered positive based on the cycle threshold (cT) value which was <30, whereas, reactive if cT value was ≥30 and <40, and negative (cT > 40).

Results

Of the 2184 participants (528 players, 388 team staff, and 1268 local staff), 916 international participants were tested for COVID-19 PCR upon arrival at the Hamad International Airport, whereas the local staff (n = 1268) were tested 2 days before entering the bubble. The mean age of the players was 27.5 ± 9.8. Fifteen teams participated and as many as 60 matches were played over 3 weeks. Most participants tested negative (95.3%) and 3.9% tests were inconclusive. During the entire tournament, the positivity rate was 2.7% among all participants. Of the total positive cases, 0.8% were positive before entering the bubble system. The remaining (1.9%) tested positive during the tournament phase (19 players, 16 team officials, and 8 organizing committee staff).

Conclusion

Bio-secure bubble protocol operated in a controlled environment presents a minimal risk of COVID-19 infection for hosting international football events. This framework could be benchmarked to resume professional football competitions under unprecedented pandemic situations.

COVID-19 modifications of offseason and preseason training for NFL athletes are associated with increased risk of regular season injuries

OBJECTIVES

COVID-19 altered National Football League (NFL) player and team training during the 2020 offseason. All preseason games were cancelled resulting in absence of game play before the first week of the regular season. Thus, concerns exist regarding injury susceptibility of players during regular season games. The purpose of this study was to evaluate and compare injury rates during the 2020 NFL season versus injury rates from the unaffected 2017-2019 seasons. We hypothesized there would be an increased injury rate and an increased rate of season ending injuries during the modified 2020 season.

METHODS

The NFL's public injury database was queried to identify players placed on the injury lists throughout the 2017-2020 seasons. All players listed as "out" and on the injured reserve due to physical injury were included in the data set. For further stratification, injury incidence was separated based on position. Time missed due to COVID-19 illness was not included. Injury rates were expressed as injuries per 1000 athlete exposures (AE).

RESULTS

Overall, 893 individual players missed games due to injury during the 2020 NFL regular season compared to an average of 743 over the 2017-2019 seasons. Defensive players at all positions had a statistically significant increase in injury incidence from an average of 7.54 to 10.20 injuries per 1000 AE. Defensive backs were most affected with a 46% increase in players injured. There was no statistically significant difference in season ending injuries for any position.

CONCLUSIONS

The COVID-19 stricken 2020 NFL regular season saw an increased rate and incidence of injuries. Specifically, defensive players had a higher incidence of injury overall with defensive backs experiencing the greatest increase in injury rates.

Exploring the impact of the COVID-19 pandemic in Euroleague Basketball

The aim of this study was to understand how training and playing conditions during the COVID-19 pandemic affected the performance of Euroleague Basketball players. Using a non-participant observation analysis, the study compared the seasons before the lockdown (2018-2019 and 2019-2020; pre-pandemic) with the season after restart (2020-2021; pandemic). Paired t-tests and Wilcoxon tests were applied for variables with normal and non-normal distributions, respectively. The results revealed significant changes (p < 0.05) in several offensive and defensive performance-related variables during pandemic times (without attendance): free throw attempts, free throw percentage, turnovers, three-point attempt rate, fouls (small effect sizes, ESs), points, and possessions (trivial ES). The pre-pandemic HA (70%) significantly decreased after the lockdown, with games played with no crowd (∼51%; p = 0.018, large ES). The one-sample t-test showed that the HA after the COVID-19 interruption was not significantly greater than 50%, indicating that the HA did not endure during the pandemic condition. Although significant differences between home and away teams were found for most performance-related variables (excepting turnovers) in both pre-pandemic and pandemic conditions, variations of the relative HA were only significant for free throw attempts (large ES), points (medium ES), and turnovers (medium ES). The results of this study showed that performance variables were affected by the COVID-19 lockdown. Thus, these findings may help coaches, players, and referees to counteract unwanted competitive events and improve their overall performance, regardless of the contextual/situational circumstances encountered.

Physical exercise, immune response, and susceptibility to infections-current knowledge and growing research areas

This review presents state-of-the-art knowledge and identifies knowledge gaps for future research in the area of exercise-associated modifications of infection susceptibility. Regular moderate-intensity exercise is believed to have beneficial effects on immune health through lowering inflammation intensity and reducing susceptibility to respiratory infections. However, strenuous exercise, as performed by professional athletes, may promote infection: in about half of athletes presenting respiratory symptoms, no causative pathogen can be identified. Acute bouts of exercise enhance the release of pro-inflammatory mediators, which may induce infection-like respiratory symptoms. Relatively few studies have assessed the influence of regularly repeated exercise on the immune response and systemic inflammation compared to the effects of acute exercise. Additionally, ambient and environmental conditions may modify the systemic inflammatory response and infection susceptibility, particularly in outdoor athletes. Both acute and chronic regular exercise influence humoral and cellular immune response mechanisms, resulting in decreased specific and non-specific response in competitive athletes. The most promising areas of further research in exercise immunology include detailed immunological characterization of infection-prone and infection-resistant athletes, examining the efficacy of nutritional and pharmaceutical interventions as countermeasures to infection symptoms, and determining the influence of various exercise loads on susceptibility to infections with respiratory viruses, including SARS-CoV-2. By establishing a uniform definition of an "elite athlete," it will be possible to make a comparable and straightforward interpretation of data from different studies and settings.

Football in Times of COVID-19: A Recapitulation of Preventive Measures and Infection Control Policies Aiming at a Safe Game Environment

Coronavirus disease 2019 (COVID-19) resulted in sporting event suspensions and cancellations, affecting competition calendars worldwide during 2020 and 2021. This challenged high-performance athletes' capacity to complete physical, technical, or tactical training during restricted movement measures (lockdown). With the Football World Cup organized in the last quarter of 2022, the past period of training and match disturbances challenged footballers concerning their performance and potential higher risk of injury at official matches' resumption. There has been considerable debate about the management of resuming professional football (soccer) during the COVID-19 pandemic. Governing bodies worldwide implemented measures to ensure a safe resumption of football. These precautionary measures aimed to protect the health of players, their support staff, and officials around the pitch and ensure the enjoyment of the event by spectators in the football stadiums. We have therefore narratively reviewed scientific papers about how football has resumed on the pitch and in the stands with special focus on the COVID-19 infection control strategies allowing footballers to perform again and supporters to enjoy the game after the 2020 global stop to sport.

Sleep behavior and training load in adolescent elite basketball players during COVID-19 pandemic development

The COVID-19 pandemic caused strong restrictions in organized sports. Specifically, adolescent athletes, whose daily routine is usually determined by school and practice schedules, experienced a sudden lifestyle change. The aim of this study was to examine sleep and training patterns of German elite adolescent basketball players (N = 115, 15.70 ± 1.22 years, female = 32.17%) during different phases of the 2021 lockdown. Sleep and training behavior were documented by a subjective monitoring over 10 days at three different lockdown phases in February, April, and June/July. A linear mixed model approach was conducted for the statistical analyses. Sleep duration and time in bed decreased between phase 1 (prohibition of organized sports) and phase 3 (normal training conditions), while sleep efficiency and quality increased. There was no change in training duration over time, but in training intensity, which peaked in the third phase. This study contains meaningful evidence to analyze the lockdown-related return to practice process. Athletes were able to maintain training duration with alternative protocols during pandemic conditions. Interestingly, athletes slept less under non-lockdown conditions, but reported a better sleep quality. It is recommended to consider athletes' individual preferences when planning training and recovery schedules.

Injury Characteristics among Young Adults during and Immediately after the COVID-19 Lockdown

The lockdown due to the COVID-19 pandemic inherently changed people’s lifestyles. Forty-eight days of isolation led to worsening physical fitness in addition to the development of other unhealthy habits. The aim of this study was to describe sport-related injuries in the active general population. Physical therapy centres and sports medicine clinics were contacted via e-mail, seeking patients who had sustained an injury during or immediately (up to two weeks) after the lockdown. Patients who agreed to participate completed an online survey that followed the International Olympic Committee Statement. The questionnaire focused on physical exercise habits, type of injury, location and tissue affected. A total of 51 females and 67 males (30.5, SD = 8.8 years) participated in the study. Eighty percent of the participants performed aerobic training sessions, while the rest dedicated their workouts to strength training. Two in every three injuries were located in the lower limbs, and 80% affected the musculoskeletal tissue. Of all the injuries recorded, 67% occurred during the first week after lockdown. The number of aerobic exercise sessions was positively correlated with lower limb injuries (χ2 = 17.12, p < 0.05). Exercise habits should be considered when planning to return to a sport after a period of confinement to avoid injury.

Leadership experiences of elite football team physicians during the COVID-19 pandemic: a pilot study

Objectives

The purpose of this study was to explore the leadership experiences of elite football team physicians during the COVID-19 pandemic.

Methods

A pilot-study based on a cross-sectional design by means of an electronic survey was conducted. The survey relied on 25 questions divided into distinct sections including among others professional and academic experience, leadership experiences and perspectives.

Results

A total of 57 physicians (91% male; mean age: 43 years) gave their electronic informed consent and completed the survey. All participants agreed that the demands of their role had increased during the COVID-19 pandemic. Fifty-two (92%) participants reported that they felt they were expected to take more of a leadership role during the COVID-19 pandemic. Eighteen (35%) reported feeling under pressure to make clinical decisions which were not in keeping with best clinical practice. Additional roles, duties and demands expected of team doctors during the COVID-19 pandemic were subdivided into communication, decision-making, logistical, and public health demands.

Conclusion

The findings from this pilot study suggest that the way in which team physicians at professional football clubs operate has altered since the onset of the COVID-19 pandemic, with greater demands placed on leadership skills including decision-making, communication and ethical stewardship. This has potential implications for sporting organisations, clinical practice and research.

Recommencement of football competition with spectators during the active phase of the COVID-19 pandemic in a Middle Eastern country

Background

With the global spread of COVID-19 infection caused by the severe acute respiratory syndrome coronavirus-2 virus (SARS-CoV-2), all the national and international sports events were ceased early in 2020. The sport activities have been reinstated since then, albeit without spectators. However, several governments have established a variety of risk-mitigation measures to gradually reintroduce the spectators to stadiums.

Objectives

We aimed to evaluate the implementation of a strict health protocol to ensure the resumption of professional football with spectators and to access its effectiveness in limiting the spread of COVID-19 infections within the community.

Methods

This was a retrospective, observational study involving football players, match officials, local organizing committee members, working in close coordination, and over 16,000 spectators in the state of Qatar. We examined data from the Amir Cup final (December 18th, 2020), which was played under a strict protocol that included extensive reverse transcription-Polymerase chain reaction (RT-PCR) testing for players and match officials, as well as the utility of COVID-19 rapid antigen and antibody testings as screening tools for spectators to ensure their safe return to the stadiums. In addition, we reviewed the guidelines and protocols that were put in place to organize Qatar's Amir Cup Football Final, which drew over 16,000 spectators in the stadium.

Results

A total of 16,171 spectators undertook rapid antigen and antibody tests for the Amir cup final (from December16-December18, 2020). Fifteen Spectators (n = 15) returned with a positive result for COVID-19 infection during the final event (positivity rate = 0.12%). All players underwent RT-PCR testing 48 h before the match. None of the players tested positive for COVID-19 infections. 1311 individuals reported having symptoms related to COVID-19 post final of Amir Cup. These spectators were tested for COVID-19 RT-PCR with an overall positivity rate (positive/reactive) to be 0.42% (69/16171).

Conclusion

This report shows a meagre incidence rate of COVID-19 infections during and post-Amir Cup football final. Based on the low infectivity rate reported during and post the Amir Cup, we propose that supervised and controlled resumption of football matches with spectators can be carried out safely following a strict testing and tracing protocol. Similar infection control policies can be replicated with a higher number of spectators.

Effect of COVID-19 on Injury Rates and Timing in the National Football League

Background:

The coronavirus 2019 (COVID-19) pandemic resulted in the cancellation of the 2020 National Football League (NFL) preseason and a decreased preseason roster size. The effect of this disruption on athlete injury rates is unknown.

Purpose/Hypothesis:

The purpose was to quantify the rates of anterior cruciate ligament (ACL), Achilles tendon, and hamstring tendon injuries in NFL players before and after the COVID-19 pandemic. We hypothesized that injury rates in the 2020 season would be higher than those seen prepandemic.

Study Design:

Descriptive epidemiology study. Level of evidence, 4.

Methods:

An online search using publicly available data was carried out to identify all NFL players who sustained an ACL, Achilles tendon, or hamstring tendon injury between April 1, 2017, and March 31, 2021. Data collected included player characteristics as well as career and season of injury workloads.

Results:

The number of Achilles tendon (27 vs 20; P = .024) and hamstring tendon (186 vs 149; P < .001) injuries, respectively, in the 2020 NFL season were significantly higher than the average of the 2017 to 2019 seasons. However, the number of ACL injuries sustained remained constant (43 vs 46; P = .175). More than half (52.9%) of ACL injuries in the 2017 to 2019 seasons occurred in the preseason, while most of the injuries (34.9%) in the 2020 season occurred in weeks 1 to 4. There was no player characteristic or career workload variable collected that was significantly different for players who sustained an ACL, Achilles tendon, or hamstring tendon injury in the 2020 NFL season compared with the 2017 to 2019 seasons.

Conclusion:

In the 2020 NFL season, the number of Achilles tendon and hamstring tendon injuries rose while the number of ACL injuries remained constant compared with the 2017 to 2019 seasons. Injuries that occurred during the first 4 games of the 2020 NFL season were consistent, with higher rates of injuries seen in the preseason in previous years.

COVID-19 Impact on the Sport Sector Economy and Athletic Performance

As COVID-19 continues to impact global health, and educational, financial, commercial institutions, sport, in particular, has not been spared [...]

COVID-19 Confinement Effects on Game Actions during Competition Restart in Professional Soccer Players

The main objective of the present study was to compare high-intensity actions in a week of three matches before and after the COVID-19 lockdown. The observational methodology was used. This study analysed 551 professional soccer players from 22 different Spanish teams (LaLiga Smartbank 2019−2020) by a multi-camera tracking system and associated software (Mediacoach®, Spain). Variables of distances per minute and totals, travelled at High Intensity (HIR), Very High Intensity (VHIR), Sprint (HSR), player’s maximum speed, average speed, and the number of efforts in VHIR and HSR were analysed in the first and second half of the games, the full match, as well as in relation to the playing position. Players who participated in the same number of matches pre- and post-COVID-19 showed an increase in the total minutes played, p < 0.05, and small decreases in game actions, p < 0.05, with an effect size between 0.21 and 0.45, while players who participated in different number of matches pre- and post-COVID-19 showed a performance decrease, p < 0.05, with a size effect between 0.13 and 0.51; this was evident, particularly, for midfielders, p < 0.05, with a size effect between 0.39 and 0.75. The results seem to show that the playing intensity after COVID-19 confinement did not lead to large performance losses, except for midfielders who were the most involved players and showed a higher decrease in performance. The main findings of this study could provide insight to football coaches for rotations in starting line-ups and game substitutions, so as not to affect the intensity levels of the competitions.

LaLiga Lockdown: Conditioning Strategy and Adaptation to In-Game Regulations during COVID-19 Pandemic Prevented an Increase in Injury Incidence

The first division of Spanish professional football (LaLiga) was suspended for 12 weeks as part of the policies enforced by health authorities during the first wave of COVID-19. During this period, players were confined to home for 8 weeks, followed by a club-based retraining period of 4 weeks. Afterwards, LaLiga’s teams completed 11 matches, with approximately 3 days of recovery between matches, to finish the competition. The aim of this investigation was to determine whether there is a difference in mean injury incidence in LaLiga players between the pre-lockdown period and post-lockdown period. A total of 277 players belonging to 11 teams competing in LaLiga were monitored during the 2019–2020 season. Injury incidence in the 27 matchdays completed before the lockdown was compared to the last 11 matchdays completed after the resumption of the competition. In comparison to the period before the suspension, the resumption of the championship did not significantly affect the injury incidence (4.2 vs. 5.4 injuries per 1000 h of exposure, p = 0.338). Injury incidence before suspension and after resumption of the competition was similar for muscle (2.6 vs. 3.4 injuries per 1000 h of exposure, p = 0.152) and ligament injuries (0.8 vs. 0.4 injuries per 1000 h of exposure, p = 0.062). The resumption of the competition also did not modify the distribution of injury according to body location (p = 0.948), injury type (p = 0.766), mode of onset (p = 0.614), severity (p = 0.065), or player position (p = 0.295). In summary, mean injury incidence in LaLiga players was similar before and after the lockdown. It is probable that the conditioning strategy adopted by clubs before the resumption of LaLiga and the adaptation of some in-game regulations helped to avoid an increased injury rate after the lockdown.

Impact of Prolonged Absence of Organized Training on Body Composition, Neuromuscular Performance, and Aerobic Capacity: A Study in Youth Male Soccer Players Exposed to COVID-19 Lockdown

The aim of this study is to examine how physical performance has changed after 15 weeks (109 days) long-term absence of organized training in youth soccer players imposed by the stay at home orders. A total of sixty-eight young male soccer players from different age categories (U15, U16, U17 and U19) voluntarily participated in the prospective cohort study. Body fat percentage (BF%), counter-movement jump (CMJ), 30 m sprint, change-of-direction (COD) and yo-yo intermittent recovery test level-1 (YYIRTL-1) were evaluated twice (before and after the detraining period). Subsequently, 2 × 2 repeated measures ANOVA was used to investigate group and time differences in repeated measurements. A significance level of p < 0.05 was implemented. CV and SWC values were calculated to test the reliability of the tests performed at different times. Statistical analysis was performed using the IBM SPSS statistics software (v.25, IBM, New York, NY, USA). Significant increments in BF%, 30 m sprint, and COD (left and right), and also significant decrements in CMJ and YYIRTL-1, were found after the detraining period. A long-term detraining period due to the stay at home orders has a detrimental effect on body composition, neuromuscular performances, and aerobic capacity in youth soccer players.

Neuromuscular Impairment of Knee Stabilizer Muscles in a COVID-19 Cluster of Female Volleyball Players: Which Role for Rehabilitation in the Post-COVID-19 Return-to-Play?

COVID-19 athletes reported persistent and residual symptoms many weeks after initial infection, including cough, fatigue, and neuromuscular disorders. Poor neuromuscular control may cause inefficient movement strategies increasing anterior cruciate ligament load. This is particularly relevant in female athletes, who show a 3-time higher risk than male counterparts. Aim is to evaluate the impairment in thigh muscles activation, body composition, and physical performance after COVID-19 in volleyball athletes. We recruited a cohort of female professional players from the same team. We assessed the pre-activation time of Rectus Femoris (RF), Vastus Medialis (VM), Medial Hamstring (MH), and Lateral Hamstring (LH) before (T0) and after (T1) COVID-19 infection, bioelectrical impedance analysis (BIA), and jump tests. We included 12 athletes with COVID-19 infection diagnosis in January 2021. At T1 we found a significant (p < 0.05) delay (ms) of the activation time of RF (426 ± 188 vs. 152 ± 106); VM (363 ± 192 vs. 140 ± 96); BF (229 ± 60 vs. 150 ± 63); MH (231 ± 88 vs. 203 ± 89), and a significant reduction of body composition at BIA. The neuromotor imbalance of the knee stabilizer muscle in female athletes after COVID-19 infection determines a deficit of knee stabilization. Physicians should consider neuromuscular and metabolic sequelae to identify athletes at higher risk of injury and set up specific neuromuscular rehabilitation protocols.

Pediatric orthopedic injury prevention for team sports post COVID-19

Queries of youth orthopedic sports injuries from the U.S. National Electronic Surveillance System, a database from the Consumer Product Safety Commission, demonstrate decreased orthopedic injuries related to team sports during the COVID-19 pandemic, indicative of reduced sports participation. Multiple articles have shown that COVID-19 had a marked effect on the physical and psychological wellbeing of the youth. The lockdown resulted in a cessation in school attendance and sports activities, especially team sports. Though increased emphasis has been placed on children infected by COVID-19, less attention has been given to healthy children. Numerous articles discussed the physical and psychological benefits for the youth returning to physical activity and sports; however, few have addressed detraining and deconditioning concerns postpandemic. This article discusses a safe return to team sports for the youth experiencing physical and psychological changes related to the pandemic. Orthopedic injuries are anticipated to increase as restrictions are relaxed. A multidisciplinary team presents a review of common youth sports orthopedic injuries, a discussion of psychological issues youths have experienced during COVID and why sports participation is beneficial for youth, and a risk assessment for pain and limited range of motion for youth returning to sports. The intent of this article is to increase awareness of the physical and psychological changes experienced by youth due to their inability to participate in team sports during the pandemic. Family medicine and primary care providers need to recognize the increased risks for injury and proactively encourage the youth to return to sports in a safe manner.

ACL injury prevention: Where have we come from and where are we going?

Anterior cruciate ligament (ACL) injuries are one of the most common and severe knee injuries across sports. As such, ACL injury prevention has been a focus of research and sports medicine practice for the past three-plus decades. Examining the current research and identifying both clinical strategies and research gaps, the aim of this review is to empower clinicians and researchers with knowledge of where the ACL injury prevention literature is currently and where it is going in the future. This paper examines the mechanism of ACL injury prevention, screening, implementation, compliance, adherence, coronavirus, and areas of future research. Clinical significance: The time lag between research and practical implementation in general healthcare settings can be as long as 17 years; however, athletes playing sports today are unable to wait that long. With effective programs already established, implementation and adherence to these programs is essential. Strategies such as coaching education, increasing awareness of free programs, identifying barriers, and overcoming implementation obstacles through creative collaboration are just a few ways that could help improve both ACL injury prevention implementation and adherence.

Organising football matches with spectators during the COVID-19 pandemic: What can we learn from the Amir Cup Football Final of Qatar 2020? A call for action

The COVID-19 pandemic is a potential threat to professional sporting events when they eventually return to their usual calendar with spectators’ capacity of football stadiums usually exceeding 40,000 seats for important events. Hence, a strategy for safe return to sporting events is needed in the COVID-19 pandemic to pave the way towards a new normalcy. We reviewed the guidelines and policies implemented in organising the Amir Cup Football Final of Qatar, which hosted about 20,000 fans. The authors evaluated the publicly available information on the official websites of the various organizations involved and highlight the importance and usefulness of the Covid-19 Rapid Antigen Assay-Kit as a tool for screening sports spectators as well as the importance of a rigorous spectator pathway, including their accurate traceability thanks to a specific mobile phone application. Despite the surging of COVID-19 all over the world, a big football event with around 20,000 spectators in the same stadium has been hosted under strongly controlled preventative measures. These preventative measures show that it is possible to organize a major football match held outdoors, with the presence of thousands of supporters. This article is a call for action for the organisers of such events where the supporters’ health status is traceable to provide the scientific community with actual data of post-event infection rates. Therefore, it is suggested to consider using procedures like the ones described in the present article as a potential model in the process of organizing big sporting events with spectators in times of COVID-19.

Are elite track and field athletes on track? The impact of COVID-19 outbreak on sleep behavior and training characteristics

The Covid-19 outbreak forced many governments to enter a nationwide lockdown. The aim of this study was to evaluate, by means of a survey, changes in sleep parameters and physical activity characteristics of elite track and field athletes in three periods: before the lockdown (T0), during the lockdown (09th March – 03rd May 2020, T1) and the first month after the lockdown (T2). This study was conducted from May 2020 to June 2020 and data were collected using an offline survey with 89 elite track and field athletes (mean age: 24.7 ± 5.4; n = 43 males; n = 46 females). The survey consisted of demographic data and questions on physical activity and sleep behavior at T0, T1 and T2. Athletes reported lower sleep quality scores at T1 compared to T0 and T2 (p < 0.0001) and registered delayed bedtime, wake-up time and longer sleep latency during the lockdown compared to pre-lockdown and post-lockdown whereas no changes in total sleep time were reported. No inter-group differences were detected in sleep characteristics between short- and long-term disciplines and between genders. The weekly training volume decreased from 16.1 ± 5.7 hours at T0 to 10.7 ± 5.7 hours at T1 (p < 0.0001) whereas no significant differences were detected in training volume during the lockdown in relation to the square footage of the house (p = 0.309). Alcohol (p = 0.136) and caffeine intake (p = 0.990) and use of electronic devices (p = 0.317) were similar pre-, during, and post-lockdown. The unprecedented circumstances of the Covid-19 pandemic had negative impacts on the Italian track and field athletes’ sleep and training volumes.

The effects of COVID-19 lockdown on jumping performance and aerobic capacity in elite handball players

The aim of this research was to analyse the capacity of a home-based training programme to preserve aerobic capacity and jumping performance in top-level handball players during the COVID-19 lockdown. Eleven top-level male handball players from the same team participated in the study. A submaximal shuttle run test and a counter-movement jump test were used to measure the players’ aerobic fitness and lower limb explosive strength, respectively. A 9-week home-based training programme was followed during lockdown. Pre-test measurements were assessed before the pandemic on 29 January 2020 and ended on 18 May 2020. Moderate significant mean heart rate increases were found in the late stages of the submaximal shuttle run test after the lockdown (stage 5, 8.6%, P = 0.015; ES = 0.873; stage 6, 7.7%, P = 0.020; ES = 0.886; stage 7, 6.4%, P = 0.019; ES = 0.827). Moderate significant blood lactate increases were observed immediately after the submaximal shuttle run test following the lockdown (30.1%, P = 0.016; ES = 0.670). In contrast, no changes were found in jump performance. A structured home-based training programme during the COVID-19 lockdown preserved lower limb explosive strength but was an insufficient stimulus to maintain aerobic capacity in top-level handball players.

The impact of COVID-19 lockdown on professional soccer players' body composition and physical fitness

During the COVID-19 lockdown, professional soccer players ceased their regular team training sessions and were provided with exercise programs to follow independently. This investigation assessed the impact of a 7-week COVID-19 lockdown and home-based individual physical training on professional soccer players’ body composition and physical fitness. The study consisted of nineteen division 1 elite soccer players (age 27.68 ± 5.99 years, height 178.47 ± 5.44 cm) and compared the anthropometric and physical fitness parameters obtained post-transition period to those obtained post-COVID-19 lockdown. The statistical analysis indicated that body fat percentage was significantly higher after the lockdown period [t(18) = -5.59, p < 0.01, d = 0.56]. Furthermore, VO_2max [t(17) = -11.54, p < 0.01, d = 0.57] and running time [t(17) = 3.94, p < 0.01, d = 0.76] values were significantly higher after the COVID-19 lockdown than those obtained after the transition period. In addition, significantly higher level of performance was demonstrated on squat jump [t(18) = -4.10, p < 0.01, d = 0.30], countermovement jump [t(18) = -7.43, p < 0.01, d = 1.11] and sit and reach tests [t(19) = -5.33, p < 0.01, d = 0.32]. Concurrently, lower body strength was indicated to be significantly greater (p < 0.01) following the COVID-19 lockdown. The training protocol provided during the confinement, due to the COVID-19 outbreak, was effective in keeping physical fitness at a significantly higher level compared to the transition period. Coaches and trainers are encouraged to examine the effectiveness of this protocol, as it may help them develop effective periodization programs during the transition period. This protocol may aid in the development of effective periodization programs that require minimal equipment and can be followed in similar situations.

The Effect of the COVID-19 Lockdown on the Position-Specific Match Running Performance of Professional Football Players; Preliminary Observational Study

The COVID-19 pandemic interrupted professional football in the 2019/2020 season, and football experts anticipate that the consequences of lockdown measures will negatively affect the physical performance of players once competition restarts. This study aimed to evaluate position-specific match running performance (MRP) to determine the effect of COVID-19 lockdowns on the physical performance of professional football players. Players’ MRPs (n = 124) were observed in matches before and after the COVID-19 lockdown in the 2019/2020 season of the highest level of national competition in Croatia and were classified according to player position: central defenders (CD; n = 42), fullbacks (FB; n = 20), midfielders (MF; n = 46), and forwards (FW; n = 16). The MRPs were measured using Global Positioning System, and included the total distance covered, low-intensity running (≤14.3 km/h), running (14.4–19.7 km/h), high-intensity running (≥19.8 km/h), total accelerations (>0.5 m/s²), high-intensity accelerations (>3 m/s²), total decelerations (less than –0.5 m/s²), and high-intensity decelerations (less than –3 m/s²). The results indicated that, in matches after the COVID-19 lockdown, (i) CDs and FBs featured lower running and high-intensity running (t-value: from 2.05 to 3.51; all p < 0.05; moderate to large effect sizes), (ii) MFs covered a greater distance in low-intensity running and achieved a lower number of total accelerations, and total and high-intensity decelerations (t-value: from –3.54 to 2.46; all p < 0.05, moderate to large effect sizes), and (iii) FWs featured lower high-intensity running (t-value = 2.66, p = 0.02, large effect size). These findings demonstrate that the physical performances of football players from the Croatian first division significantly decreased in matches after the COVID-19 lockdown. A combination of inadequate adaptation to football-specific match demands and a crowded schedule after the competition was restarted most likely resulted in such an effect.

Training During the COVID-19 Lockdown: Knowledge, Beliefs, and Practices of 12,526 Athletes from 142 Countries and Six Continents

Objective

Our objective was to explore the training-related knowledge, beliefs, and practices of athletes and the influence of lockdowns in response to the coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Methods

Athletes (n = 12,526, comprising 13% world class, 21% international, 36% national, 24% state, and 6% recreational) completed an online survey that was available from 17 May to 5 July 2020 and explored their training behaviors (training knowledge, beliefs/attitudes, and practices), including specific questions on their training intensity, frequency, and session duration before and during lockdown (March–June 2020).

Results

Overall, 85% of athletes wanted to “maintain training,” and 79% disagreed with the statement that it is “okay to not train during lockdown,” with a greater prevalence for both in higher-level athletes. In total, 60% of athletes considered “coaching by correspondence (remote coaching)” to be sufficient (highest amongst world-class athletes). During lockdown, < 40% were able to maintain sport-specific training (e.g., long endurance [39%], interval training [35%], weightlifting [33%], plyometric exercise [30%]) at pre-lockdown levels (higher among world-class, international, and national athletes), with most (83%) training for “general fitness and health maintenance” during lockdown. Athletes trained alone (80%) and focused on bodyweight (65%) and cardiovascular (59%) exercise/training during lockdown. Compared with before lockdown, most athletes reported reduced training frequency (from between five and seven sessions per week to four or fewer), shorter training sessions (from ≥ 60 to < 60 min), and lower sport-specific intensity (~ 38% reduction), irrespective of athlete classification.

Conclusions

COVID-19-related lockdowns saw marked reductions in athletic training specificity, intensity, frequency, and duration, with notable within-sample differences (by athlete classification). Higher classification athletes had the strongest desire to “maintain” training and the greatest opposition to “not training” during lockdowns. These higher classification athletes retained training specificity to a greater degree than others, probably because of preferential access to limited training resources. More higher classification athletes considered “coaching by correspondence” as sufficient than did lower classification athletes. These lockdown-mediated changes in training were not conducive to maintenance or progression of athletes’ physical capacities and were also likely detrimental to athletes’ mental health. These data can be used by policy makers, athletes, and their multidisciplinary teams to modulate their practice, with a degree of individualization, in the current and continued pandemic-related scenario. Furthermore, the data may drive training-related educational resources for athletes and their multidisciplinary teams. Such upskilling would provide athletes with evidence to inform their training modifications in response to germane situations (e.g., COVID related, injury, and illness).

Supplementary Information

The online version contains supplementary material available at 10.1007/s40279-021-01573-z.

Return to competitive gymnastics training in the UK following the first COVID-19 national lockdown

Following the outbreak of COVID-19 (coronavirus), the UK entered a national lockdown, and all sport was suspended. The study aimed to explore the process of returning to gymnastics training after several months away from the gym, with a particular interest towards training load and injury. Twenty-six, national programmed gymnasts from Men's artistic, Women's artistic and Trampoline gymnastics recorded training load and injury whilst returning to training. At the end of data collection, three coaches were interviewed to further explore the experiences and practices of returning to training. Home-based training during lockdown was seen as beneficial in maintaining a level of fitness. Coaches described a gradual increase in training to reduce the risk of injury, and this partly explains a non-significant association between training load and a substantial injury (p = 0.441). However, week-to-week changes in training load following periods of additional restrictions (additional lockdown, periods of isolation, or substantial restrictions) were not always gradual. There was a significant association between an injury in the preceding week (niggle or substantial injury to a different body part) and a substantial injury in the subsequent week (RR: 5.29, p = 0.011). Monitoring training was described to be a useful practice during the process of returning to training. Coaches believed that although the short-term development of their gymnasts was affected, the long-term development would not be impacted from COVID-19. It is anticipated that learnings from this study can be applied to future practices and situations, particularly when gymnasts are away from the gym for an extended period.

Impact of COVID-19 lockdown on the epidemiology of soccer muscle injuries in Italian Serie A professional football players

OBJECTIVE

To evaluate the influence that COVID-19 lockdown had on the epidemiology of soccer musculoskeletal injuries during 2019/2020 Italian First Football League Serie A in professional football players.

METHODS

In this retrospective study we analyzed records from media-based platform (Trasfermarkt, https://www.transfermarkt.com), describing the epidemiology of muscle injuries before and after the first COVID-19 lockdown phases in Italian professional football players. We also classified the severity of the injury as the number of missing days from participation.

RESULTS

We assessed a lower prevalence of post-lockdown injuries, albeit showing a similar injury rate at 1000 game-hours (pre-lockdown: 16.9 [13.0-20.7], post-lockdown: 15.5 [9.9-21.1]; RR: 0.92 [0.46-1.8]). All risk ratios for injury rate were not significantly different (p> .05) between pre- and post-lockdown.

CONCLUSIONS

The incidence of muscle injuries has not significantly changed after the first COVID-19 lockdown in Italian professional soccer players. Recognizing injury rates might be crucial for physician to evaluate adequate preventive measures.

Effect of COVID-19 on Ulnar Collateral Ligament Reconstruction in Major League Baseball Pitchers

Background:

The coronavirus disease of 2019 (COVID-19) pandemic led to the suspension and shortening of the 2020 Major League Baseball (MLB) season from 162 to 60 regular season games. The effect of this disruption on injury rates, specifically injury to the ulnar collateral ligament (UCL), has not been quantified.

Purpose/Hypothesis:

The purpose of this study was to compare the rate of UCL reconstruction (UCLR), surgery timing, and pitching workload in MLB pitchers from before and after the COVID-19 pandemic lockdown. We hypothesized that UCLR rates relative to games played would be increased and pitching workload would be decreased in 2020 compared with previous seasons.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

An extensive online search using publicly available data was conducted to identify all MLB pitchers who underwent UCLR between January 1, 2017, and December 31, 2020. Only pitchers who were competing at the MLB level when undergoing reconstruction were included. Player characteristics and surgery date, as well as career and season of surgery pitching workload, were collected for all included pitchers. All data were compared as a pooled sample (2017-2019 vs 2020).

Results:

A similar number of pitchers underwent UCLR during or after the 2020 regular season (n = 18) compared with the 2017-2019 seasons (n = 16, 20, and 16, respectively). However, after accounting for the decrease in games played during the 2020 regular season, an MLB pitcher was 2.9 times more likely to undergo surgery per game after the COVID-19 lockdown compared with the previous years (P < .001). MLB pitchers who underwent surgery in 2020 threw fewer preseason innings than did pitchers who underwent surgery between 2017 and 2019 (5.98 vs 9.39; P = .001).

Conclusion:

MLB pitchers were almost 3 times more likely to undergo UCLR per game after the COVID-19 lockdown. A decreased preseason pitching workload because of the COVID-19 lockdown may have had an effect on per game UCLR rates.

The Influence of COVID-19 Pandemic Lockdown on the Physical Performance of Professional Soccer Players: An Example of German and Polish Leagues

The purpose of this study was to investigate whether the in-season pandemic lockdown influenced physical match performance in professional soccer players who participated in the competition of German Bundesliga and Polish Ekstraklasa. The data from 306 games for German Bundesliga and 296 games for Polish Ekstraklasa were divided into before- and after-lockdown periods. The physical performance of German Bundesliga teams after the 63-day COVID-19 lockdown did not differ significantly from that in the first part of the season. In contrast, Polish Ekstraklasa teams, after the 81-day lockdown, displayed significantly shorter total distances (p < 0.001), shorter high-intensity running distances (p = 0.03), and fewer high-intensity actions (p = 0.02). Moreover, when the effective playing time was considered, teams covered significantly less relative total distance (p < 0.001) and relative high-intensity running distance (p = 0.02). The results of the current study suggest that physical performance during the matches of the German Bundesliga was not influenced by the COVID-19 lockdown, contrary to those of the Polish Ekstraklasa. This difference could have been caused by different break lengths and different restrictions implemented in these countries during the pandemic lockdown.

Relationship between Training Load Management and Immunoglobulin A to Avoid Immunosuppression after Soccer Training and Competition: A Theoretical Framework Based on COVID-19 for Athletes' Healthcare

Immunoglobulin A (IgA), which is the main effector against upper respiratory tract viruses such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been related to training load management. The aim of this systematic review was to establish the relationship between training load and salivary IgA based on current evidence in order to avoid immunosuppression after exercise and players´ vulnerability to virus contagion. A systematic review of relevant articles was carried out using two electronic databases (PubMed and Web of Science) until 19 May 2021. From a total of 127 studies initially found, 23 were included in the qualitative synthesis. These studies were clustered depending on stress level. The salivary IgA was analysed considering soccer-specific treadmill exercise and repeated sprint drills (n = 5), matches (n = 7), and during certain periods during the season or pre-season (n = 11). Repeated sprint ability tests and treadmill exercises are suitable exercises for the first steps on return to play periods yet still maintain social distance. A rest or moderate training sessions (technical/tactical) are suggested after official matches to ensure 16-18 h to recover IgA levels, while periods with multiple matches per week with limited recovery time should be avoided. Weekly training load should assume a small increment (<10%) to ensure IgA immune responses, especially, during the post coronavirus disease 2019 (COVID-19) season.

Competitive anxiety or Coronavirus anxiety? The psychophysiological responses of professional football players after returning to competition during the COVID-19 pandemic

OBJECTIVE

This study aimed to examine the relationship between competitive anxiety, fear/anxiety of COVID-19, and autonomic and endocrine stress responses in professional football players after returning to competition during the COVID-19 pandemic.

METHODS

Ninety male professional football players (age: 26.33 ± 2.48 yr) volunteered to participate in this study, which included an official competition. Psychophysiological responses, including the Fear of COVID-19 Scale, the Coronavirus Anxiety Scale, and the Competitive State Anxiety Inventory-2 Revised, were collected 30 min before the competition. In addition, salivary alpha-amylase (sAA) and salivary cortisol (sCort) were collected at 8 a.m. and 15 min before the competition.

RESULTS

The main findings, based on the Pearson correlation, showed significant positive correlations between COVID-19 anxiety and somatic competitive anxiety (p = 0.01), cognitive competitive anxiety (p = 0.01), and competition response of sCort and sAA (p = 0.01). Moreover, fear of COVID-19 was positively correlated with COVID-19 anxiety (p = 0.01). On the contrary, the awakening response of sCort and sAA was not found to be correlated with psychological parameters (all p > 0.05). The analysis also indicated that there was no significant correlation between self-confidence with other psychological and physiological variables (all p > 0.05). The regression analysis showed that cognitive anxiety was a relevant predictor for the competition response of sCort and sAA (p < 0.05). Moreover, COVID-19 anxiety was the only predictor of somatic and cognitive anxiety (p < 0.05).

CONCLUSIONS

The present study provides the first preliminary evidence that COVID-19 anxiety and competitive anxiety might pose a negative impact on the athletic performance of professional football players during COVID-19 pandemic competitions. Thus, research is needed to build a strategy to reduce the psychophysiological stress related to COVID-19 and competition response.

Running Patterns in LaLiga Before and After Suspension of the Competition Due to COVID-19

In the first wave of the COVID-19 outbreak (spring 2020), the first division of professional soccer in Spain (LaLiga) was suspended for 12 weeks as part of the lockdown imposed by the Spanish health authorities. Professional soccer players were confined to home for 8 weeks and then a retraining period of 4 weeks was set before the first competitive match. When competition was resumed, professional soccer teams competed in a congested calendar (11 matchdays in 39 days) while some in-game regulations were altered (up to 5 substitutions, refreshment pauses). The current research presents an analysis of running patterns before suspension and after resumption of LaLiga to determine how the lockdown affected players’ physical performance. To aid in this purpose, a pairwise comparison was performed of running patterns of the 2019–2020 vs. 2018–2019 season (i.e., control season). Using a two-way ANOVA (season x matchday), it was found that there was no main effect of the season on total running distance per match (P = 0.288) nor in the distances covered < 14.0 km/h (P = 0.294), at 21.0–23.9 km/h (P = 0.266), and at ≥ 24.0 km/h (P = 0.112). Only the distance at 14.0–20.9 km/h was affected by the season (P = 0.019) with a lower running distance on matchday 34 in the 2019–2020 vs. 2018–2019 season. The number of substitutions (from 2.9 to 4.5 substitutions per game; P < 0.001) and match duration (96 vs. 100 min; P < 0.001) significantly increased after resumption respect to the previous season. These data suggest that high-intensity running performance of professional soccer teams was maintained after the resumption of the competition while the alterations likely aided in the in-game regulations facilitated the maintenance of soccer physical performance.

Comparative Analysis of Soccer Performance Intensity of the Pre-Post-Lockdown COVID-19 in LaLiga™

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) forced a stoppage in the 2019/2020 season of LaLiga™, possibly influencing performance indicators in the return to competition. Therefore, here, we evaluated whether the stoppage due to the coronavirus 2019 disease (COVID-19) lockdown influenced physical performance compared to the start of LaLiga^TM in terms of high-intensity efforts. Using a semi-automatic, multiple-camera system, running activities during 22 matches were analyzed. We compared the first 11 matches of the season (pre-lockdown) with the 11 matches just after the restart of LaLiga™ (post-lockdown). The results showed higher (p < 0.05) performance in the pre-lockdown period compared with the post-lockdown period, including in medium-speed running (14.1–21 km/h), high-speed running (21.1–24 km/h), and sprinting speed running distances (>24 km/h). However, the number of accelerations/min and decelerations/min were significantly higher during the post-lockdown period. Therefore, we conclude that the stoppage due to the COVID-19 lockdown generated lower physical performance in the post-lockdown period compared with the pre-lockdown period, most likely due to the accumulation of matches (congested schedules).

Case Report: Return to Sport Following the COVID-19 Lockdown and Its Impact on Injury Rates in the German Soccer League

The Bundesliga made headlines for becoming the first major sports league to return to sport worldwide following COVID-19 lockdown. To-date, there lacks retrospective studies on longitudinal injury rates to elucidate the effect isolation measures had on the health and safety of professional athletes. This study sought to compare injury rates experienced by Bundesliga athletes before and after the COVID-19 lockdown. Data was collected from public injury and player reports regarding the Bundesliga, with injury defined as trauma resulting in loss of game time. Descriptive statistics were used to present differences in injury incidence between all Bundesliga Match days pre- and post-lockdown. Between the league's resumption and completion on May 16 and June 27, 2020, injuries occurred in 21 forwards (FW), 11 central midfielders (CM), 12 wide midfielders (WM), 16 central defenders (CD), 6 fullbacks (FB), and 2 goalkeepers. Players had 1.13 (95% CI 0.78, 1.64) times the odds of being injured following the COVID-19 lockdown, with a 3.12 times higher rate of injury when controlling for games played compared to injury rates pre-lockdown (0.84 injuries per game vs. 0.27 injuries per game). The most frequent injury group was muscular injuries with 23 injuries total, with 17% of athletes experiencing injury during their first competitive match following lockdown. Injury rate increased over 3-fold following COVID-19 lockdown. Athletes did not experience an increased rate of injury with more cumulative competitive matches played. High injury incidence for players yet to complete their first competitive match may imply suboptimal sport readiness following home confinement.

Playing Non-Professional Football in COVID-19 Time: A Narrative Review of Recommendations, Considerations, and Best Practices

The coronavirus disease (COVID-19) pandemic in 2020 resulted in widespread interruption of team sports training and competitions. Our aim was to review the recommendations and best practices in return to play in non-professional football after activity lockdown. The authors searched two electronic databases (PubMed, Web of Science) to extract studies published before September 15 2020. Twenty studies explained recommendations, considerations, or best practices in return to play in football, and all of them were clustered into three groups: (1) training load management (n = 10), (2) medical recommendations (n = 9), and (3) recovery related issues (n = 5). The way to establish a progression in training process should be based on training load management and managing the number of stimuli per time. Following the studies, this training process should be divided into three phases: phase 1-physical distancing should be maintained; phases 2 and 3-group training should start. Medical considerations were clustered into different groups: general, pre- and post- training, during training, education, planning to return to competition, and suggestions for post confinement weeks. In particular, social issues, strict hygiene questions, and continuous PCR testing should be considered in return to play over football season. Finally, since a correlation has been found between high-intensive training loads and immunoglobulin A, nutritional and lifestyle recovery strategies should be performed. Moreover, since immunosuppression has been related to congested schedules (<72 h between matches), football federations should avoid this situation.