title: 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.affiliation: Department of Health Sciences, University of Rome IUSM, Rome, Italy. luigi.diluigi@iusm.it
authors.forename: L
authors.initials: L
authors.lastname: Di Luigi
authors.forename: C
authors.initials: C
authors.lastname: Baldari
authors.forename: F
authors.initials: F
authors.lastname: Pigozzi
authors.forename: G P
authors.initials: GP
authors.lastname: Emerenziani
authors.forename: M C
authors.initials: MC
authors.lastname: Gallotta
authors.forename: F
authors.initials: F
authors.lastname: Iellamo
authors.forename: E
authors.initials: E
authors.lastname: Ciminelli
authors.forename: P
authors.initials: P
authors.lastname: Sgrò
authors.forename: F
authors.initials: F
authors.lastname: Romanelli
authors.forename: A
authors.initials: A
authors.lastname: Lenzi
authors.forename: L
authors.initials: L
authors.lastname: Guidetti
mesh_terms: D000328:Adult; D015308:Anaerobic Threshold / Q000187:drug effects*; D002243:Carbolines / Q000008:administration & dosage / Q000494:pharmacology*; D018592:Cross-Over Studies; D003692:Delayed-Action Preparations / Q000494:pharmacology*; D004311:Double-Blind Method; D005080:Exercise Test / Q000379:methods; D006801:Humans; D007558:Italy; D008297:Male; D010101:Oxygen Consumption / Q000187:drug effects* / Q000502:physiology; D010726:Phosphodiesterase Inhibitors / Q000008:administration & dosage / Q000494:pharmacology*; D010807:Physical Endurance; D010919:Placebos / Q000008:administration & dosage / Q000494:pharmacology; D000068581:Tadalafil
chemical_list: D002243:Carbolines; D003692:Delayed-Action Preparations; D010726:Phosphodiesterase Inhibitors; D010919:Placebos; D000068581:Tadalafil