University of Miami, Department of Kinesiology and Sport Sciences, Coral Gables, Florida 33146, USA.
High Alt Med Biol. 2011 Fall;12(3):215-22. doi: 10.1089/ham.2011.0011.
Sildenafil improves maximal exercise capacity at high altitudes (∼4350-5800 m) by reducing pulmonary arterial pressure and enhancing oxygen delivery, but the effects on exercise performance at less severe altitudes are less clear.
To determine the effects of sildenafil on cardiovascular hemodynamics (heart rate, stroke volume, and cardiac output), arterial oxygen saturation (SaO2), and 6-km time-trial performance of endurance-trained men and women at a simulated altitude of ∼3900 m.
Twenty men and 15 women, endurance-trained, completed one experimental exercise trial (30 min at 55% of altitude-specific capacity +6-km time trial) at sea level (SL) and two trials at simulated high altitude (HA) while breathing hypoxic gas (12.8% FIo2) after ingestion of either placebo or 50 mg sildenafil in double-blind, randomized, and counterbalanced fashion.
Maximal exercise capacity and SaO2 were significantly reduced at HA compared to SL (18%-23%), but sildenafil did not significantly improve cardiovascular hemodynamics or time-trial performance in either men or women compared to placebo and only improved SaO2 in women (4%). One male subject (5% of male subjects, 2.8% of all subjects) exhibited a meaningful 36-s improvement in time-trial performance with sildenafil compared to placebo.
In this group of endurance trained men and women, sildenafil had very little influence on cardiovascular hemodynamics, SaO2, and 6-km time-trial performance at a simulated altitude of ∼3900 m. It appears that a very small percentage of endurance-trained men and women derive meaningful improvements in aerobic performance from sildenafil at a simulated altitude of ∼3900 m.
确定西地那非对心血管血液动力学（心率、每搏量和心输出量）、动脉血氧饱和度（SaO2）和 6 公里计时赛表现的影响，在模拟海拔约 3900 米的环境中对耐力训练的男性和女性的影响。
20 名男性和 15 名女性耐力训练者在海平面（SL）完成一项实验性运动试验（55%的海拔特定能力+6 公里计时赛 30 分钟），并在服用安慰剂或 50mg 西地那非后在模拟高海拔（HA）进行两次试验，以双盲、随机和平衡方式进行。
与 SL 相比，HA 时最大运动能力和 SaO2 明显降低（18%-23%），但与安慰剂相比，西地那非并没有显著改善男性或女性的心血管血液动力学或计时赛表现，仅在女性中提高了 SaO2（4%）。一名男性受试者（男性受试者的 5%，所有受试者的 2.8%）在服用西地那非时与安慰剂相比，计时赛表现有了有意义的 36 秒提高。
在这组耐力训练的男性和女性中，西地那非对模拟海拔约 3900 米时的心血管血液动力学、SaO2 和 6 公里计时赛表现影响非常小。似乎只有一小部分耐力训练的男性和女性从模拟海拔约 3900 米的西地那非中获得了有意义的有氧运动表现的改善。
