It is reported about the preliminary results of a first clinical examination of O2MT in 46 patients. The "regeneration effect of O2MT" (v. Ardenne) is represented as an increase of resting values of arterial oxygen tension (PO2a), which demonstrable in about 2/3 of the patients. This effect continues more than 3 months after the end of O2MT. It is succeeded by "prophylactic and therapeutic effects, which were discussed as an improvement of cardiorespiratory and cardiovascular efficiency. The O2MT is suggested as a new treatment-method in premorbidities, who evolved out a "latent hypoxemia", especially for the use of preventive-treatment and gerontology-therapy.