https://www.hammernutrition.com/knowledge/endurance-library/diet-for-increasing-natural-epo
https://sci-hub.se/10.1080/026404199365795
Does exercise intensity increase EPO?
It’s complicated. Roberts & Smith measured the effects of exercise-induced hypoxia on the physiological production of erythropoietin. Twenty athletes exercised for 3 min at 106-112% maximal oxygen consumption. The fitness of these athletes provides a physiological environment for increasing EPO naturally from short 3-minute all-out intervals. Estimated oxyhemoglobin saturation was measured by reflective probe pulse oximetry (Nellcor N200) and was validated against arterial oxyhemoglobin saturation by CO-oximetry in eight athletes. Serum erythropoietin concentrations, as measured using the INCSTAR Epo-Trac radioimmunoassay, increased significantly by 19-37% at 24 hours post-exercise in 11 participants who also had an arterial oxyhemoglobin saturation < or = 91%. Decreased ferritin levels and increased reticulocyte counts were observed at 96 hours post-exercise. However, no significant changes in EPO levels were observed in nine non-desaturating athletes and eight non-exercise controls. Good agreement was shown between arterial oxyhemoglobin saturation and percent estimated oxyhaemoglobin saturation (limits of agreement = -3.9 to 3.7. They concluded that a short 3 minutes supramaximal exercise period could induce both hypoxemia and increased erythropoietin levels in well-trained individuals. The decline of arterial hypoxemia levels below 91% during exercise appears to be necessary for the exercise-induced elevation of serum erythropoietin levels. Furthermore, reflective probe pulse oximetry was found to be a valid predictor of percent arterial oxyhemoglobin saturation during supramaximal exercise when percent estimated oxyhemoglobin saturation > or = 86%
