Going High: Countermeasures to Mitigate Altitude Effects on Performance

It is well established that aerobic exercise performance is impaired at altitude when compared to sea level. The decrement in performance is a result of lower partial pressure of oxygen (O 2 ) at altitude which reduces arterial partial pressure of O 2 and arterial O 2 saturation. Altitude exposure induces integrative physiological responses by the cardiovascular system to attenuate hypoxemia, but those responses are insufficient to mitigate performance decrements. Aside from altitude acclimatization which can be costly and logistically challenging to implement, there are no known countermeasures to mitigate altitude-induced impairment in performance. Using an integrative physiological approach we experimentally tested whether recombinant human erythropoietin (rEPO) or iron administered intravenously (IV-iron), which have different physiological mechanisms to potentially attenuate the altitude-induced hypoxemia, can mitigate performance decrements. First, recombinant human erythropoietin (rEPO) increases hemoglobin mass and O 2 carrying capacity which effectively improves performance at sea level. We reasoned that the physiological and ergogenic benefits of rEPO would carry over to high altitude environments. We will discuss the effect of rEPO on hemoglobin mass, O 2 carrying capacity, and performance at high altitude. Second, previous literature has shown that IV-iron alleviates hypoxic pulmonary vasoconstriction attenuating O 2 desaturation at high altitude particularly during resting conditions. Moreover, the physiological effects of IV-iron persist for prolonged period of time (~ 6 weeks). We will discuss IV-irons effect on resting and exercise O 2 saturation as well as performance at high altitude 24 hours and two weeks after iron administration. Our work leverages the physiological effects induced by pharmacological countermeasures to augment physiology and performance at high altitude. Supported by USAMRDC; author views not official US Army or DoW policy. This abstract was presented at the American Physiology Summit 2026 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.