Swimming competitions in the era of COVID-19: Lessons from successfully hosting the International Swimming League.

Background: Organization of mass sport events in the COVID-19 era is utterly complicated. Containments measures, required to avoid a virus outbreak, force athletes to compete under circumstances they never experienced before, most likely having a deleterious effect on their performance. Purpose: We aimed to design a so-called athlete-friendly bubble system for the International Swimming League 2020 event, which is strict enough to avoid a COVID-19 outbreak, but still provides a supportive environment for the athletes. Methods: To avoid the feeling of imprisonment, athletes were permitted to spend a certain amount of time in the parks surrounding the hotels. Such alleviations were possible to apply with strict adherence to the hygienic and social distancing protocols and regular COVID-19 testing. Evaluation of every COVID-19 positive case was key, and if prolonged PCR positivity or false positive PCR result was identified, the unnecessary quarantine was planned to be lifted. Return to play protocol (RTP) was planned, in case of a COVID-19 infection of an athlete inside the bubble. To test, if the athlete-friendly system provided a supportive environment, we evaluated athlete performance. Results: 11,480 PCR tests were performed for 1,421 individuals. 63 COVID-19 positive cases were detected, of which 5 turned out to be clinically insignificant, either because of prolonged PCR positivity or because of a false positive result. 93.1% of the positive cases were detected in the local crew, while no athlete got infected inside the bubble, as the two infected athletes were tested positive upon arrival. RTP was provided for two athletes. 85% of the athletes showed improvement during the bubble and 8 world records were broken. Conclusion: The applied protocol proved to be effective, as no athlete got infected inside the bubble, moreover, the athlete-friendly system supported the athletes to improve their performance.

Effect of extracellular volume expansion and surgical stress on splanchnic blood flow and cardiac output in anesthetized rats: role of nitric oxide.

In a normal volume state, surgical stress decreases rather than increases nitric oxide (NO) production in the vascular system. In our studies, the effect of minor and major surgical stress and three different degrees of volume expansion on systemic and splanchnic circulatory parameters and on the NO dependence of the circulation have been investigated. When the degree of volume expansion was increased, cardiac output and organ blood flow increased without significant change in vascular resistances. Major surgical stress reduced the increase in cardiac output and organ blood flow elicited by the volume expansion. NO synthase (NOS) inhibition significantly increased blood pressure and total peripheral resistance (TPR) and decreased cardiac output in all groups of animals. As the degree of volume expansion was increased, the NO dependence of the circulation in the surgically less- and more-stressed animals was inversely influenced in some cases. With the three degrees of volume expansion (20, 40, and 60 ml/kg), the NOS inhibition increased the TPR from 30.7 R/kg +/- 1.90 to 73.6 R/kg +/- 5.00, from 20.7 R/kg +/- 1.43 to 66.7 R/kg +/- 3.88, and from 19.9 R/kg +/- 1.25 to 49.1 R/kg +/- 3.84 in the surgically less-stressed animals and from 38.6 R/kg +/- 2.14 to 59.8 R/kg +/- 5.62, from 31.9 R/kg +/- 2.70 to 81.7 R/kg +/- 9.89, and from 29.1 R/kg +/- 2.49 to 91.1 R/kg +/- 6.36 in the surgically more-stressed animals. Volume expansion increases the NO dependence of the vascular resistance in the surgically more-stressed animals but decreases it in the surgically less-stressed animals.