Effects of the Corona Pandemic on Competitive Sports – an Online Survey Amongst 2981 German and Austrian Elite Athletes

Between April 21st 2020 and February 16th 2021, a total of 2981 questionnaires could be recruited. 2144 questionnaires were collected until September 30th 2020, 837 between October 1st 2020 and February 16th 2021.The athletes’ characteristics are set out in table 1. Mean training years were 16.2±2.0 SE.

Number of Confirmed infections and Quarantine During the Inquiry Period
78 athletes, or 2.62%, reported having a positive PCR test result for SARS-CoV-2. In addition, 67 (2.25%) athletes reported that they had experienced the disease but were self-diagnosed (e.g. due to loss of smell, but without a positive test having been carried out or a doctor having been consulted). In 19 athletes (0.64%), infection was suspected by a physician but without testing. Of the remaining athletes, 444 (14.89%) reported that they had a negative test. A total of 841 athletes (28.2%) stated that they were in quarantine at least once during the query period. In 81 people due to a positive test, 254 people (8.52%) due to contact with a positive person, 198 (6.64%) due to stay in a risk area. Self-initiated quarantine was performed by 308 athletes (10.33%). The percentage of athletes who were not in quarantine decreased from 78.2% during the first survey period to 64.5% during the second survey period (p<0.0001).

Possible Symptoms of COVID-19 during Query Period
Symptoms that might be associated with COVID-19 were observed in a high percentage of athletes. 38.7% reported to have had at least one symptom possibly indicating an infection with SARS-CoV-2. The most prevalent symptoms were rhinitis, sore throat and cough (see table 2).

Athletes with PCR Confirmed COVID-19
From the 78 athletes with PCR confirmed COVID-19, 38 (48.7%) were older than 18 but younger than 30 years, 23 (29.4%) younger than 18 years and 17 (21,8%) older than 30 years. 44/78 (56.4%) were female athletes. Age had a significant influence on the likelihood of having had a positive test (Chi² 0.0001), as did the type of sport practiced with most infections in endurance athletes (Chi² 0.0051), whereas no influence of gender could be detected (Chi² 0.2756). Athletes of Austrian nationality had indicated a positive test significantly more often than athletes of German nationality (42/720 vs. 35/2204 or 5.83% vs. 1.59%, p>0.0001). Symptom duration differed by infection status (Chi²<0.0001): While only about 1% had a history of a confirmed infection with SARS-CoV-2 at the first period of the survey, this increased to 6.5% at the second period of the survey. Further details and symptoms are given in table 3.

Cardiac Symptoms in Athletes with and without COVID-19
Cardiac symptoms were reported significantly more often in PCR positive athletes than in the group of athletes without confirmed infection or no infection (odds ratio 3.57 [2.48-5.13], palpitations p=0.0063, dizziness p=0.0038. tachycardia p<0.0001, chest pain p<0.0001, table 4). In terms of syncopes no difference could be observed.

Duration of Symptoms, Hospitalization and Training Interruption
Most athletes recovered from symptoms (cardiac or non-cardiac) within one week. However, 186 athletes were symptomatic for more than one week. Athletes with confirmed infection had significantly longer symptoms than athletes without confirmed infection (more than 7 days of symptoms 45.5% vs. 16.0%). Despite symptoms training was not interrupted by 516 athletes, whereas training interruption in the others was predominantly at least 6 days. 15 athletes (0.5%) were admitted to hospital due to COVID-19, 8 of them were hospitalized for more than 1 week.

Concerns due to the Pandemic and Impairment of Sports Activity
The percentage of athletes who were not concerned about the pandemic decreased from 31% (first survey period) to 14% (second survey period). Worries about their own health in particular increased significantly over the course of the study. table 6 shows the type of worries by survey period.
Training was considerably affected by the pandemic. 29.5% indicated in the first query period that they were strongly or very strongly (39.6%) impacted in their exercise. This percentage decreased to 24.9% and 15.7% percent respectively in the second query period. The reporting of concerns was significantly lower at the second query time point than at the first query time point (p<0.001). Details are given in table 7.

The results of the online survey show several findings. Firstly, the high willingness to fill out the questionnaire was surprising although of course we do not know how many people the questionnaire was actually sent to. A population of almost three thousand competitive and professional athletes is certainly unique in this context and indirectly shows the relevance of the topic for competitive sports.

Infection with SARS-CoV-2 in Elite Athletes
As might be expected, the proportion of confirmed infections with SARS-CoV-2 was initially very low. This can be explained by the low testing capacity, especially at the beginning of the pandemic. Therefore, questions were also asked about suspected infections. These could be either physician-diagnosed or self-diagnosed. Diagnosis by a physician or self-diagnosis was based on the appearance of typical clinical symptoms, first and foremost a loss of smell (8). Thus, a total of about 5.5% of the participants assumed to have been infected.

However, there is probably a high number of unreported cases, because an infection can be asymptomatic (3, 6), with younger age being associated with a higher likelihood of an asymptomatic course (7). In our study, 15% of those with confirmed infection remained asymptomatic. The proportion of asymptomatic infected individuals varies depending on the population studied. For example, in a study of health professionals, the proportion of asymptomatic infections was reported to be 2.4% (6). In contrast, a model describing the dynamics of COVID-19 assumes 10% asymptomatic infections (1). Both figures are thus lower than the proportion we documented. There are several possible explanations for this:

First, among infected athletes, the proportion of athletes under 18 years of age was relatively high at nearly 30 percent, favoring an asymptomatic course. Second, it can be assumed that asymptomatically infected athletes were discovered in the course of routine tests, as they were performed relatively early in competitive sports. Thus, the transferability of these findings to the general population is limited, respectively not possible.

Interestingly, a positive test was indicated more frequently in Austria than in Germany, which may have different reasons. Firstly, the questionnaire was made public later in Austria, so that there was a longer period of time between a potential infection and the completion of the questionnaire, which increases the probability of an infection. Of course, this also applies when considering the first and second query periods for the entire collective, which must be regarded as a limitation. On the other hand, PCR tests might have been available earlier in Austria (in competitive sports) than in Germany.
It remains to be noted that potential symptoms of infection with SARS-CoV-2 were reported relatively frequently (38% of participants). However, symptom duration was significantly longer in the group with confirmed infection with SARS-CoV-2 than in the group without confirmed infection, which would suggest that part of the group without proven infection had only experienced common viral or bacterial infections during the query period. Only the loss of smell already would be considered in this context as actually pathognomonic for COVID-19. However, it has also been shown that it is symptoms such as fever (present in 7.5% in our study), muscle pain (7.5%), and cough (17.7%) that increase the likelihood of being infected with SARS-CoV-2 (6). Thus, the determined incidence of approximately 5.5% in our sample should therefore only represent a lower limit of the actual contamination. On the other hand, it can be argued that especially in competitive athletes - at least in the professional field - testing was performed early in the course of the pandemic when symptoms occurred and thus the proportion of undetected infections could be reduced.

Cardiac Symptoms in Athletes with Confirmed COVID-19
Already in the early phase of the pandemic, there were reports that COVID-19 could also lead to cardiac symptoms or affections (5). This was initially observed mainly in hospitalized individuals. In the meantime, several studies have been conducted on smaller groups of athletes (2, 4), which, however, have come to very different conclusions. This is certainly also due to the fact that different examination methods were used in the studies. In addition, it is well known that symptoms and examination findings can vary over time following infection with SARS-CoV-2 (9). Unfortunately, the data we collected do not allow us to draw any conclusions about the time course of symptoms, as the questionnaire was deliberately designed to be simple in order to keep the response rate high. In any case, it remains to be noted that cardiac symptoms were reported more frequently in cases of confirmed infection than in the rest of the athletes.

Although the participating volunteers consisted of highly trained and obviously healthy competitive athletes, 15 persons had to be treated as inpatients due to the infection. This shows that despite a high level of fitness and a relatively young age, severe courses can occur. Thus, preventive measures such as hygiene concepts and vaccination, which was not yet widely available at the time of the survey, are also necessary in top-level sport.

Impact on Sporting Activity and Concerns of the Athletes
In addition to direct consequences due to infection, there was also a massive indirect impact on sporting activity. 28% of participants in the survey reported having been quarantined at least once. In addition to the (at least temporary) closure of sports facilities, this had a massive impact on training and athletic performance.

Supplementary questions were asked about concerns of the athletes. Whereas in the first survey period 31% said they were not worried, this proportion fell to 14% in the course of the survey. There was a significant increase in the number of concerns about their own health. This could have been due to cases in the personal environment with a more complicated course of COVID-19, but this remains speculative. Interestingly, financial concerns were not at the forefront. This may be due to the fact that in the youth sector, livelihoods are not financed by sport or that professional athletes, who made up a high proportion of the participants, were able to build up a financial cushion in advance. In addition, many top-level athletes receive support from the public sector (e.g., the Federal Armed Forces), which continued during the pandemic.

The study has some limitations. For example, it is unclear how high the response rate to the questionnaire was, as the number of emails sent with the link to the survey is not known. Furthermore, the motivation to participate in the survey might be higher among infected or symptomatic persons than among non-infected persons. Ultimately, the data only refer to the first year of the pandemic, in which wild-type virus and the alpha variant were predominant and vaccinations were not available until the beginning of 2021. Therefore, the data cannot be transferred to other virus variants or vaccinated athletes. Another limitation is that no medical records are available to verify the information and the impact of possible confounders was not evaluated by multi-variate analysis.

- The pandemic with SARS-CoV-2 has a massive impact on elite sports.
- At least 5.5% of elite athletes (PCR-diagnosed, self-diagnosed or diagnosed by a physician without testing) suffered from COVID-19 between February 2020 and February 2021.
- Potential symptoms of infection with SARS-CoV-2 were reported in 38% of all participating athletes.
- Cardiac symptoms were reported more frequently by infected athletes than by the rest of the athletes surveyed.
- Severe courses with hospitalization are rare among elite athletes, but not excluded.

Our online survey confirmed a massive impact of the pandemic on sports. More than 28% of the participants in the survey had been quarantined at least once. While only about 1% were confirmed to be infected during the first period of the survey, this increased to 6.5% at the second time. 15% of athletes who were tested positive had no symptoms, which could indicate a high number of unreported cases, especially at the beginning of the pandemic, when comprehensive testing was not yet available. Additionally, a high proportion of potential symptoms of infection with SARS-CoV-2 were also found in the overall collective. Despite symptoms, not all athletes have taken a break from training.

Cardiac involvement of infection seems likely, even in top-level athletes. Thus, a higher proportion of cardiac symptoms were found in confirmed infection. Although participants were competitive athletes who typically have high fitness and good health, hospitalization was required in approximately 0.5% of cases.
During the course of the survey, a smaller impact on training was found. This is most likely due to the fact that special arrangements were made for top athletes. Irrespective of this, a high number of competitive athletes were concerned about their health and athletic career, and these concerns even increased in the course of the survey.

This study was supported by a grant of the “Deutsche Herzstiftung e.V.”

Conflict of Interest
The authors have no conflict of interest.