Continuously measured oxygen uptake during constant work exercise (15′ 50W) reveals increasing oxygen consumption in individuals with elevated blood viscosity parameters, indicating persistent contribution of anaerobic glycolysis during steady state exercise far below expected “anaerobic threshold”. Improvement of viscosity parameters by prostaglandin E1 infusion (Prostavasin®) 40 μg i.v., naftidrofurylhydrogenoxalat (Dusodril® pi) 400 mg i.v. or hemodilution with 500 ml 6% hydroxyethylamylum MW 40000(Onkohaes®) in 5 patients results in significant reduction of this oxygen gradient in subsequent exercise test. Integrated VO2 during exercise above the mean value at rest or the quotient of VO2 during 15 min by VO2 during 30 min (including recovery time) are not differing significantly due to high variations inter- and intraindividually. Oxygen gradient during submaximal constant exercise permits direct clinical determination of microcirculatory performance in involved muscle tissue as a function of blood viscosity.
