Clenbuterol and Cycling

Published: May 10, 2010Posted in: News
Clenbuterol and Cycling

Have you ever found difficulty riding in cold weather; your chest feeling so tight that you can hear your lungs wheezing? How long does it take for your body to warm up and your breathing to feel natural? Have you ever exercised at altitude for the first time and noticed that you can’t ride as hard or as long? How many days does it take for you to acclimatize where you can workout like you do at sea level? These scenarios give you a glimpse of what a person with asthma feels before and after taking a prescribed inhaler to treat their symptoms. Do you remember how your body feels on that first ride of the Spring season, or after a long layoff? Your arms and torso feel unnatural on the handle bars and saddle, and your legs feel heavy. Contrast that a few months later when you are in midseason peak form. Your technique is smooth, your waist and hips are slim, and your quadriceps generate more power and show more definition.

If there was a super drug that could make you breath easier, workout longer and harder, trim your body fat, and enhance your muscles, would you take it? Those are the effects of Clenbuterol (street name, “Clen”), and athletes have been abusing it for years. It is banned by the World Anti-Doping Association, International Olympic Committee, and United Cycling International as an illegal performance enhancing drug.

Clenbuterol is not approved for use by the United States Food and Drug Administration, but is commonly prescribed in other countries to treat asthma patients. It can also be purchased on the internet in tablet, syrup, or injectable forms. Its biochemical mechanism of action is as a beta-agonist that helps open up the airways, similar to other common inhalers like Proventil. Another effect through an unclear mechanism of action shows that is reduces body fat by lipolysis and enhances muscle growth through protein synthesis. Although it is not a steroid, its anabolic steroid-like effects place it on the banned substance list. Clenbuterol levels decay in the human body by 50% every 36 hours (i.e., “half-life”), so the levels take a few weeks to become undetectable and its effects can be long-lasting.

Historically, Clenbuterol’s effect on increasing lean muscle mass was capitalized upon by many countries that raised food-producing animals such as cattle, sheep, and swine. While the drug produced few adverse effects to the animals, food poisoning has occurred in humans known to have ingested meat contaminated with high doses of Clenbuterol. Symptoms of nausea, headaches, tremors, palpitations, convulsions and even heart attacks have been seen in these cases. Over the past two decades, outbreaks of food poisoning from Clenbuterol-tainted meat have been seen in Europe, the United States, and most recently in China.

Therein lies a dilemma in finding an athlete who tests for abnormally high doses of Clenbuterol in his urine test. Could the athlete have ingested tainted meat that caused his high sample levels?  If so, one would think that the athlete would have suffered the symptoms of food-poisoning. Also, within a few weeks, his system would have been rid of the drug. Does food poisoning provide a convenient alibi for the accused athlete, or is it the culprit of an innocent act? As with all alleged cases of performance enhancing drug use, the governing sports bodies have a difficult responsibility in weighing the scientific origin of an abnormal test result.

By Jerome Enad, MD, staff writer