(1) Background: The aim was to explore the impact of adaptive responses (resilience factors) on student-athletes’ behaviors during a stressful period of life during the SARS-CoV-2-pandemic of 2020 and 2021. (2) Methods: A constructivist-based grounded theory (CGT) was used guided by a biopsychosocial approach. Based on purposeful sampling, 22 male and female student-athletes were divided into four focus group interviews (FGI) seven months after the outbreak of the SARS-CoV-2-pandemic (October 2020) and 18 of these were followed up by FGI seven months later (May 2021). The mean age was 17.65 and they represented golf and handball. (3) Results: The CGT contained four main categories seven months after the SARS-CoV-2-pandemic outbreak: Social support, Self-discipline, Physical practice and recovery and Management of everyday life. Fourteen months after the SARS-CoV-2-pandemic outbreak, four additional main categories emerged: More extensive social support, Belief in the future, Self-awareness and Responsibility and problem-solving. (4) Conclusions: The CTG suggests that student-athletes’ favorable adaptations to the stressful SARS-CoV-2-pandemic period 2020–2021 are based on a gradually developed ability to take responsibility for one’s own actions, insight into the importance of deepened social interaction, belief in a positive post-COVID future and increased awareness of physical activity and its relation to perceived health. © 2022 by the authors.