Tourism sector has been one of the most affected sectors by the COVID-19 pandemic. One of the sectors that comprises economies in many countries is ski sector. However, the winter season 2020/2021 was suspended in many ski destinations all over the world. The aim of this research is to investigate the adaptation of downhill skiers to ski area closures in the Czech Republic during the COVID-19 pandemic. The methodology draws upon an online discussion forum which provides good data for a content analysis, a method used for both quantitative and qualitative approaches. By utilizing both approaches a good comprehension of downhill skiers' adaptation to ski area closures in the Czech Republic during the COVID-19 pandemic is provided. Particularly, four key findings can be concluded based on this research. Firstly, both the quantitative and qualitative analyses have shown that information substitution was the most frequent one among all discussion forum users. Secondly, involuntary/forced substitution proved to be a significant form of behavioural adaptation and should be considered especially when assessing the implications of the COVID-19 pandemic or dealing with other threats and challenges such as natural disasters, wars, terrorist attacks or another pandemic. Thirdly, the great number of non-substitutional responses mentioned in the discussions' posts was attributed to the COVID-19 pandemic. Fourthly, female downhill skiers do not participate in online discussion forums as much as male downhill skiers. Potential reasons for this are also discussed.