The Effect of Inhaled Nitric Oxide on Maximal Oxygen Consumption During Exercise in Hypoxia
Status:
Recruiting
Trial end date:
2022-12-01
Target enrollment:
Participant gender:
Summary
During exercise in conditions of low oxygen (termed hypoxia), such as mountaineering at high
altitudes, the lung blood vessels constrict in an attempt to protect the body from the
negative effects of hypoxia. It appears that this blood vessel constriction may limit the
heart to pump blood during heavy exercise, leading to reductions in exercise performance.
Inhaled nitric oxide is a drug that is known to relax the lung blood vessels. Inhaled nitric
oxide has been used to relax lung blood vessels and improve exercise capacity in patients
with chronic disease. It is unknown if similar improvements would be observed during exercise
in healthy individuals when exposed to low levels of oxygen. The goal of this study is to
determine if inhaled nitric oxide can relax the lung blood vessels and improve the heart's
pumping ability during exercise in low oxygen conditions. Further, the investigators will
determine if these improvements in lung blood vessel and heart function increase exercise
performance. Participants will complete 6 sessions over a three week period where they will
perform exercise challenges while breathing low levels of oxygen with and without inhaled
nitric oxide. The low oxygen conditions will be comparable to being at an altitude of
14,000-17,000 feet. 17,000 feet would be equivalent to standing on the summit of King Peak in
the Yukon (the 4th tallest mountain in Canada).