Cisneros, I. E., Bettencort, J., Joy, R., Zierke, J., Parker, D., & Quintana, R. (2009). Effects of sildenafil on VO2max in trained women with moderate normobaric hypoxia. ACSM 56th Annual Meeting, Seattle, Washington. Presentation number 1096.

This study determined if sildenafil, a pulmonary vasodilator, would reduce the decrement in VO2max in moderately trained women at a simulated altitude of ~3,818 m. Moderately trained women (N = 16) participated in three VO2max running tests, consisting of one sea level and two normobaric hypoxia (~3,818 m) trials with a 72-hour washout period between each. Treatment consisted of 50 mg of sildenafil and 50mg of a cellulose placebo given one hour prior to the hypoxic trials in a randomized double blind fashion. Ss acclimatized for an hour in the altitude chamber before hypoxic trials. Variables collected for each exercise test were: VO2max, resting and maximum oxygen saturation, resting and maximum heart rate, resting and maximum blood pressure, maximum O2 pulse, maximum ventilation, respiratory exchange ratio, rating of perceived exertion, end test time, and symptoms.

VO2max, resting and maximum oxygen saturation, O2 pulse, and maximum heart rate declined with normobaric hypoxia while resting heart rate, resting and maximum systolic blood pressure, resting diastolic blood pressure, ventilation, respiratory exchange ratio, rating of perceived exertion, and end test time showed no significant changes. There were no significant differences between sildenafil and placebo in any of the variables except maximum diastolic blood pressure was significantly lower in the sildenafil trial. There were no significant differences in frequencies of symptoms between sildenafil and placebo treatments.

Implication. Sildenafil did not reduce the decrement in VO2max in moderately trained women at a simulated altitude of ~3,818 m. The insignificant differences between oxygen saturation and O2 pulse for both the sildenafil and placebo trials support these findings.

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