The long-acting phosphodiesterase inhibitor tadalafil does not influence athletes' VO2max, aerobic, and anaerobic thresholds in normoxia.

Abstract

Whereas experimental studies showed that in healthy trained subjects, the phosphodiesterase-5 inhibitor (PDE-5i) sildenafil improves exercise capacity in hypoxia and not in normoxia, no studies on the effects of the long half-life PDE-5i tadalafil exist. In order to evaluate whether tadalafil influences functional parameters and performance during a maximal exercise test in normoxia, we studied 14 healthy male athletes in a double-blind cross-over protocol. Each athlete performed two tests on a cycle ergometer, both after placebo or tadalafil (at therapeutic dose: 20 mg) administration. Oxygen consumption (VO2), blood lactate, respiratory exchange ratio, rate of perceived exertion, arterial blood pressure (BP), heart frequency (HR) and oxygen pulse (VO2/HR) were evaluated before exercise, at individual ventilatory and anaerobic thresholds (IVT and IAT), at VO2max and during recovery. Compared to placebo, a single tadalafil administration significantly reduced systolic BP before and after exercise (p < 0.05), decreased VO2/HR at IVT (13.3 +/- 1.8 vs. 14.5 +/- 2.1 mL . beat (-1); p = 0.03), but did not modify individual VO2max, IVT, or IAT. In healthy athletes, 20 mg of tadalafil does not substantially influence physical fitness-related parameters, exercise tolerance, and cardiopulmonary responses to maximal exercise in normoxia; it remains to be verified if higher doses/prolonged use influence health and/or sport performance in field conditions.

• Authors: L Di Luigi, C Baldari, F Pigozzi, G P Emerenziani, M C Gallotta, F Iellamo, E Ciminelli, P Sgrò, F Romanelli, A Lenzi, L Guidetti
• Journal: International journal of sports medicine (Int J Sports Med) Vol. 29 Issue 2 Pg. 110-5 (Feb 2008) ISSN: 0172-4622 [Print] Germany
• PMID: 17614028 (Publication Type: Journal Article)

Chemical References

• Carbolines
• Delayed-Action Preparations
• Phosphodiesterase Inhibitors
• Placebos
• Tadalafil

Topics

• Adult
• Anaerobic Threshold (drug effects)
• Carbolines (administration & dosage, pharmacology)
• Cross-Over Studies
• Delayed-Action Preparations (pharmacology)
• Double-Blind Method
• Exercise Test (methods)
• Humans
• Italy
• Male
• Oxygen Consumption (drug effects, physiology)
• Phosphodiesterase Inhibitors (administration & dosage, pharmacology)
• Physical Endurance
• Placebos (administration & dosage, pharmacology)
• Tadalafil