Oxygen itself can react with unsaturated fatty acids without enzyme catalysis, and can destroy phospholipids, which are the main components of cell biofilm, and eventually lead to cell death. This process is called lipid peroxidation. In addition, oxygen is harmful to cells because it can produce free radicals and induce cancer.

Ordinary people should control the oxygen concentration and don't exercise too hard. If the intensity is low, it means there is something wrong with the body.