Nowadays our global society faces big challenges and threats in the times of the first major pandemic. The outbreak of COVID-19 has forced governments to impose lock-down policies around the world. Social isolation became a new normal form of living. After the first confirmed case on the 8th of March in Bulgaria, the government announced on the 14th of March the lock-down as a preventive strategy for the whole Bulgarian population. Under such circumstances, the big issue became the question of how to maintain the physical and mental health of people, and how to cope with the new reality. Based on this evidence the aim of the joint research study with Ohio State University, USA, entitled "Psychological Responses, Coping Strategies, and Physical Activity during the COVID - 19 Pandemic" has been proposed from the Bulgarian perspective as follows:1. Investigate psychological responses, coping strategies, and physical activity during the COVID - 19 lock-down periods.2. Examine the influence of physical activity as a coping strategy in psychological health hand overall well-being during social isolation.