Staying on the ball during COVID-19 pandemic: impact on training modalities in football players.

BACKGROUND: COVID-19 pandemic has affected worldwide sports competitions and training in both amateur and professional leagues. We thus aimed to investigate changes in different training modalities in elite and amateur football players following COVID-19 lockdown in March 2020. METHODS: In this cross-sectional study, we applied a Likert Scale-based questionnaire with 20 items to quantify and classify time spent at standard training methods in 47 professional and 54 amateur football players from 12 Austrian clubs before and during lockdown. Additionally, McLean Score was calculated to assess perceived training fatigue. RESULTS: Weekly amount of training time at endurance exercises (cycling) increased in both professional (37.5 [IQR 46.5] min/week vs. 187.5 [IQR 127.5] min/week, P<0.001), and amateur players (0.0 [IQR 45.0] min/week vs. 37.5 [IQR 112.5] min/week, P=0.015) during COVID-19 lockdown. Time on diverse muscle strengthening workouts was significantly elevated in both cohorts. Total training time at ball declined for professionals (from 472.5 [IQR 150] min/week to 15.0 [IQR 112.5] min/week, P<0.001) and amateurs (from 337.5 [IQR 285] min/week to 0.0 [IQR 37.5] min/week, P<0.001). Video-guided training was intensified in both groups (P<0.001 each). Location shifted from football fields and gyms to home and outdoors. Overall McLean Score remained unchanged in amateurs (P=0.42) while elite players showed a trend towards an increase (P=0.056). CONCLUSIONS: COVID-19 lockdown compromised football training, especially training concepts with ball. Consequently, resulting changes in exercise loads and muscular burden might impact susceptibility for injuries and impair performances especially in amateur players, especially as they lacked training supervision and professional training plans. Minimum effective dose of training workload to maintain endurance- and neuromuscular-related performance parameters should be prescribed.

Effects of Medical Face Masks on Physical Performance in Patients With Coronary Artery Disease or Hypertension.

In this randomized, prospective monocentric study, 40 subjects with coronary artery disease or hypertension (cardiovascular disease [CVD] group) were assigned to either surgical mask (SM) or class 2 filtering facepiece mask (FFP2). They performed cycle ergometry exercise tests with progressive intensity until exhaustion with the assigned mask and another test with no mask (NM) in random order. A control group of 10 healthy subjects randomly performed 3 exercise tests with NM, SM, and FFP2, respectively. Blood pressure, heart rate, 12-lead electrocardiogram, exertion, shortness of breath, and capillary blood gases from the earlobe were documented. Across all groups, exercise testing with face masks resulted in a significantly reduced peak power output in watts compared with testing with NM (CVD group: SM vs NM: -5.0 ± 7.0%, p = 0.005; FFP2 vs NM: -4.7 ± 14%, p = 0.03; control group: SM vs NM: -6.8 ± 4.4%, p = 0.008; FFP2 vs NM: -8.9 ± 6.3%; p = 0.01) without differences in hemodynamic parameters, such as maximum heart rate and systolic blood pressure. Wearing an FFP2 compared with NM resulted in significant higher carbon dioxide partial pressure (CVD group: FFP2: 36.0 ± 3.2 mm Hg vs NM: 33.3 ± 4.4 mm Hg, p = 0.019; control group: FFP2: 32.6 ± 2.8 mm Hg vs NM: 28.1 ± 1.7 mm Hg, p <0.001) with corresponding differences in hydrogen carbonate and base excess, but not to a clinically critical extent. In conclusion, exercise testing with SM and FFP2 resulted in a significant reduction of peak power output without differences in hemodynamic parameters in subjects with preexisting CVD and in healthy subjects.

COVID-19 in German Competitive Sports: Protocol for a Prospective Multicenter Cohort Study (CoSmo-S).

Objective: It is unclear whether and to what extent COVID-19 infection poses health risks and a chronic impairment of performance in athletes. Identification of individual health risk is an important decision-making basis for managing the pandemic risk of infection with SARS-CoV-2 in sports and return to play (RTP). Methods: This study aims 1) to analyze the longitudinal rate of seroprevalence of SARS-CoV-2 in German athletes, 2) to assess health-related consequences in athletes infected with SARS-CoV-2, and 3) to reveal effects of the COVID-19 pandemic in general and of a cleared SARS-CoV-2 infection on exercise performance. CoSmo-S is a prospective observational multicenter study establishing two cohorts: 1) athletes diagnosed positive for COVID-19 (cohort 1) and 2) federal squad athletes who perform their annual sports medical preparticipation screening (cohort 2). Comprehensive diagnostics including physical examination, laboratory blood analyses and blood biobanking, resting and exercise electrocardiogram (ECG), echocardiography, spirometry and exercise testing added by questionnaires are conducted at baseline and follow-up. Results and Conclusion: We expect that the results obtained, will allow us to formulate recommendations regarding RTP on a more evidence-based level.

A video-based analysis of situations bearing the risk of respiratory disease transmission during football matches

We aimed to analyze the number and type of contacts involving the risk of respiratory disease transmission during football match play. We analysed 50 matches from different playing levels. Two reviewers evaluated the contacts of all players in each match. We focused on between-player contacts, crowding, actions with potentially increased aerosol and droplet production and within-player hand-to-head contacts. We categorized the duels with direct contact into frontal and other ones and measured contact duration. The number of between-player contacts were similar between playing levels (median 28.3 [IQR 22.6, 33] contacts per player-hour). Frontal contacts summed up to 8% of all contacts. Contacts involving the head occurred less than once per player and match with none lasting longer than 3 s. Crowding included between two and six players and the duration was mostly less than 10 s. Aerosol and droplet producing activities were three to four times more frequent in adult compared to youth players. Our results suggest that the risk of respiratory pathogen transmission is low during football matches. This conclusion is based on the finding that most close contact situations are of short duration and on the fact that it is an outdoor sport.

COVID-19 in German Competitive Sports: Protocol for a Prospective Multicenter Cohort Study (CoSmo-S)

Objective: It is unclear whether and to what extent COVID-19 infection poses health risks and a chronic impairment of performance in athletes. Identification of individual health risk is an important decision-making basis for managing the pandemic risk of infection with SARS-CoV-2 in sports and return to play (RTP). Methods: This study aims 1) to analyze the longitudinal rate of seroprevalence of SARS-CoV-2 in German athletes, 2) to assess health-related consequences in athletes infected with SARS-CoV-2, and 3) to reveal effects of the COVID-19 pandemic in general and of a cleared SARS-CoV-2 infection on exercise performance. CoSmo-S is a prospective observational multicenter study establishing two cohorts: 1) athletes diagnosed positive for COVID-19 (cohort 1) and 2) federal squad athletes who perform their annual sports medical preparticipation screening (cohort 2). Comprehensive diagnostics including physical examination, laboratory blood analyses and blood biobanking, resting and exercise electrocardiogram (ECG), echocardiography, spirometry and exercise testing added by questionnaires are conducted at baseline and follow-up. Results and Conclusion: We expect that the results obtained, will allow us to formulate recommendations regarding RTP on a more evidence-based level.

Risk of SARS-CoV-2 transmission from on-field player contacts in amateur, youth and professional football (soccer).

OBJECTIVE: To investigate the risk of transmission among potentially infectious SARS-CoV-2-positive football players while participating in training or matches at amateur, youth and professional levels. METHODS: Between August 2020 and March 2021, football players who tested positive for SARS-CoV-2 and participated in matches or training during the period of potential contagiousness were identified through media search (professional level) and a nationwide registry in Germany (amateur and youth level) to determine symptoms, source of infection and hygiene measures adopted. The definition of potentially infectious players was based on the time of a positive PCR testing and symptom onset. Transmission-relevant contacts on the pitch were evaluated through doubly reviewed video analysis. RESULTS: Out of 1247 identified football matches and training sessions (1071 amateur and youth level, 176 professional level), 104 cases (38 training sessions, 66 matches) with 165 potentially infectious players were detected. Follow-up PCR testing at the professional level (44 cases) revealed no transmission. At the amateur and youth level, the combination of partial PCR testing (31 of 60 cases) and symptom monitoring within 14 days post-exposure (46 of 60 cases) identified 2 of 60 matches in which follow-up infections occurred that were attributed to non-football activities. This is consistent with the video analysis of 21 matches demonstrating frontal contacts were <1 per player-hour (88%, 30 of 34 players), each lasting no longer than 3 s. CONCLUSION: On-field transmission risk of SARS-CoV-2 in football is very low. Sources of infections in football players are most likely not related to activities on the pitch.

Effects of face masks on performance and cardiorespiratory response in well-trained athletes.

BACKGROUND: During the COVID-19 pandemic, compulsory masks became an integral part of outdoor sports such as jogging in crowded areas (e.g. city parks) as well as indoor sports in gyms and sports centers. This study, therefore, aimed to investigate the effects of medical face masks on performance and cardiorespiratory parameters in athletes. METHODS: In a randomized, cross-over design, 16 well-trained athletes (age 27 ± 7 years, peak oxygen consumption 56.2 ± 5.6 ml kg-1 min-1, maximum performance 5.1 ± 0.5 Watt kg-1) underwent three stepwise incremental exercise tests to exhaustion without mask (NM), with surgical mask (SM) and FFP2 mask (FFP2). Cardiorespiratory and metabolic responses were monitored by spiroergometry and blood lactate (BLa) testing throughout the tests. RESULTS: There was a large effect of masks on performance with a significant reduction of maximum performance with SM (355 ± 41 Watt) and FFP2 (364 ± 43 Watt) compared to NM (377 ± 40 Watt), respectively (p < 0.001; ηp2 = 0.50). A large interaction effect with a reduction of both oxygen consumption (p < 0.001; ηp2 = 0.34) and minute ventilation (p < 0.001; ηp2 = 0.39) was observed. At the termination of the test with SM 11 of 16 subjects reported acute dyspnea from the suction of the wet and deformed mask. No difference in performance was observed at the individual anaerobic threshold (p = 0.90). CONCLUSION: Both SM and to a lesser extent FFP2 were associated with reduced maximum performance, minute ventilation, and oxygen consumption. For strenuous anaerobic exercise, an FFP2 mask may be preferred over an SM.

Does playing football (soccer) lead to SARS-CoV-2 transmission? - A case study of 3 matches with 18 infected football players.

The risk of viral transmission of SARS-CoV-2 associated with football (soccer) training and match play is unknown. Therefore, studies on infection-relevant contacts in football are of utmost importance.A retrospective video-based analysis was performed over 3 matches with 18 SARS-CoV-2 positive players (age: 17.6 ± 3.1 years; 2 professional, 2 semi-professional and 14 youth academy players) during the pre-season in August and September 2020 in Germany. Repeated RT-PCR tests were performed in 5 of 6 teams and pre-match RT-PCR tests in 4 of 6 teams. The last RT-PCR test ranged between 5 - 14 days post-match. The most important result was that no case of virus transmission was found as documented by RT-PCR tests (and symptom monitoring up to 14 days post-match). Physical contact between contagious and non-infected players never lasted longer than 3 seconds each and the position of players during duels was almost exclusively laterally or behind each other.In conclusion, very low risk of SARS-CoV-2 transmission during football match play has been documented. Nevertheless, due to the observational retrospective design of the study, which was based on ethical reasons, inconsistent RT-PCR testing should be regarded as limitation and larger studies are needed to confirm a low probability of virus transmission.