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Physiology & Biochemistry
| Int J Sports Med 2008; 29: 110-115
DOI: 10.1055/s-2007-965131 |
© Georg Thieme Verlag KG Stuttgart · New York |
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The Long-Acting Phosphodiesterase Inhibitor Tadalafil does not Influence Athletes' V·O2max, Aerobic, and Anaerobic Thresholds in Normoxia |
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| L. Di Luigi1, C. Baldari1, F. Pigozzi1, G. P. Emerenziani1, M. C. Gallotta1, F. Iellamo2, E. Ciminelli1, P. Sgrò1, F. Romanelli3, A. Lenzi3, L. Guidetti1 |
1 Department of Health Sciences, University of Rome IUSM, Rome, Italy
2 Department of Internal Medicine, University of Rome Tor Vergata, Rome, Italy
3 Department of Medical Pathophysiology, University of Rome La Sapienza, Rome, Italy |
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 (V·O2), blood lactate, respiratory exchange ratio, rate of perceived exertion, arterial blood pressure (BP), heart frequency (HR) and oxygen pulse (V·O2/HR) were evaluated before exercise, at individual ventilatory and anaerobic thresholds (IVT and IAT), at V·O2max and during recovery. Compared to placebo, a single tadalafil administration significantly reduced systolic BP before and after exercise (p < 0.05), decreased V·O2/HR at IVT (13.3 ± 1.8 vs. 14.5 ± 2.1 mL · beat-1; p = 0.03), but did not modify individual V·O2max, 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.
Key words
erectile dysfunction - sport - nitric oxide - doping - exercise - PDE‐5
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