Covid 19 is a systemic infection that particularly affects the process of hematopoiesis and hemostasis. The coronavirus invades blood cells and increases their apoptosis. In addition, the differentiation of these cells is also disrupted during the autoimmune process by causing infection in the bone marrow. So the production and their amount are gradually reduced and their function also is disrupted. These include an initial increase in white blood cells (leukocytosis) and then a gradual decrease in leukocytes, lymphocytes, and an increase in the neutrophil/lymphocyte ratio, resulting in impaired immune function. Also, coagulation dysfunction has been reported. Actually, there is an initial increase in platelets, coagulation, markers such as fibrinogen, D-dimer, platelet to lymphocyte ratio (PLR), and then a gradual decrease in platelets (thrombocytopenia) disordered coagulation process. Coronavirus is also effective in reducing blood oxygen saturation by attacking the heme part of the hemoglobin beta chain. And immune hemolysis have also been reported in patients with covid 19. On the other hand, studies are indicated that the high intensity exercises are associated with similar hematologic changes, such as primary leukocytosis and secondary immunosuppression, increased platelet and coagulation, increased hemolysis, and decreased oxygen delivery capacity of hemoglobin. Therefore, due to the similarities in the hematological changes caused by the coronavirus and high-intensity exercise, it is recommended to avoid high-intensity exercise until the end of the corona virus prevalence period. Instead, moderate-intensity exercise is recommended.