Tour de France winner Contador tests positive for clenbuterol

For years, I had a picture of Olympic cycling from 1976 in Montreal on my bedroom wall. I tore down bikes and rebuilt them. I still have fantasies of regularly cycling again (the bike trailer with the kid is helping).

As a sport, cycling seems hopeless with all the doping. While investigators are stepping up their case against Lance Armstrong, three-time Tour de France winner Alberto Contador, tested positive for clenbuterol during the Tour.

The veterinarians in the readership know clenbuterol is a non-steroidal β2 adrenergic agonist[1] with some structural and pharmacological similarities to epinephrine and salbutamol, but its effects are more potent and longer-lasting as a stimulant and thermogenic drug. It causes an increase in aerobic capacity, central nervous system stimulation, and an increase in blood pressure and oxygen transportation. It increases the rate at which fats are metabolized, simultaneously increasing the body’s BMR. It is commonly used for smooth muscle relaxant properties. This means that it is a bronchodilator and tocolytic. It is usually used in dosages anywhere from 20-60 micrograms a day when prescribed. A dose of about 120 μg should never be exceeded in a day[citation needed]. It is also prescribed for treatment of horses; however, equestrian usage is usually the liquid form of clenbuterol. Clenbuterol is also a sympathomimetic in the peripheral nervous system.

Clenbuterol is used worldwide for the treatment of allergic respiratory disease in horses, as it is a bronchodilator. A common trade name is Ventipulmin. Particularly in North America it is also known by the slang term ‘bute.’ It can be used both orally and intravenously. It is also a non-steroidal anabolic and metabolism accelerator, through a mechanism not well understood. Its ability to increase the muscle-to-fat body ratio makes its illegal use in livestock popular to obtain leaner meats.

As of fall, 2006, clenbuterol is not an ingredient of any therapeutic drug approved by the U.S. Food and Drug Administration[2] and is now banned for IOC-tested athletes.