A pilot investigation into the effects of acute normobaric hypoxia, high altitude exposure and exercise on serum angiotensin-converting enzyme, aldosterone and cortisol.

Introduction: Aldosterone decreases at high altitude (HA) but the effect of hypoxia on angiotensin-converting enzyme (ACE), a key step in the renin-angiotensin-aldosterone system, is unclear.

Methods: We investigated the effects of exercise and acute normobaric hypoxia (NH, ~11.0% FiO) on nine participants and six controls undertaking the same exercise at sea level (SL).