Albuterol / Salbutamol Doping Works! Cyclists Just Have to Take One Pill For a 4.1% Increase in Peak Power. Plus: Its Chronic (Ab)Use Makes Their Training More Efficient

Inhaling salbutamol, which is the most appropriate way to combat asthma, will not provide the same beneficial effects to athletes as taking a much higher doses pill and thus "going systemic" will (Norris. 1996; Koch. 2013)

Salbutamol (INN) or "albuterol", as it is called in the US, is a short-acting β2-adrenergic receptor agonist. Just like its longer-acting brother clenbuterol, it has been developed to be used for the relief of bronchospasm in conditions such as asthma and chronic obstructive pulmonary disease; and just like its brother clenbuterol, it has been and still is abused by athletes all around the world as a doping agent. For good reasons?

Well, a recent study from the University of Copenhagen would suggest just that. After all, the scientists from the Department of Nutrition, Exercise & Sports, Section of Integrated Physiology found acute and long(er) term beneficial effects of salbutamol (ab)use on peak power in their subjects, 20 male endurance athletes competing in classic cycling (n = 6), mountain biking (n = 7), and triathlon (n  = 7).
The subjects were competitive at highest national level of their class. Included subjects had a weekly training volume of 14.9 ± 1.0 h/week and a VO_2max of 69.4 ± 1.8 mL/min/kg. The athletes had no history of asthma or airway symptoms and had never used anti-asthmatic medication such as beta₂-agonists. Needless to say that this changed with the onset of the study, in the course of which the subjects were randomized to either a salbutamol (SAL) (n = 10) or a placebo "supplement" (PLA) (n = 10).
At the beginning of the study, there were no differences in subject characteristics between the groups. Just like the "drug free status", this changed after only one day (!) on 8 mg salbutamol (Ventoline®, GlaxoSmithKline, Brentford, UK).

Figure 1: Effects of acute and chronic (2 week) administration of salbutamol / albuterol on peak power during wingate tests (left) and maximal voluntary contractile force in competitive cyclists (Hostrup. 2014)

As you can see in Figure 1, the drug increased the peak power during the first Wingate test by 4.1 ± 1.7% (P < 0.05). Its "chronic" ingestion for two weeks, lead to increases of 6.4 ± 2.0 and 4.2 ± 1.0% in peak power during the first and second Wingate test. Unfortunately, we don't know if a complete month would have brought about even greater increases in peak power, which would then not necessarily have been due to accumulating effects of the drug, but rather the result of an increased training efficacy (~15h of training per week). Interestingly, the provision of salbutamol did not have an effect on maximal voluntary contractile force (MVC), exercise performance at 110% of VO2max or isometric endurance (all could have been accomplished by adding caffeine, though).

Due to the short study duration, it would have been stupid to measure increases in muscle size or reductions in body fat, as they have repeatedly been observed in rodent studies with albuterol's longer-acting beta-agonist cousin, clenbuterol (you can read up on the less-known muscle building effects beta agonists and their relation to myostatin in "The Myostatin <> Clenbuterol Connection - More Muscle, Less Fat: Is an Orphan Nuclear Receptor the Missing Link?" | more).
Reference:

• Hostrup, M., Kalsen, A., Auchenberg, M., Bangsbo, J. and Backer, V. "Effects of acute and 2-week administration of oral salbutamol on exercise performance and muscle strength in athletes." Scandinavian Journal of Medicine & Science in Sports (2014). Accepted Manuscript.
• Koch, Sarah, et al. "Inhaled salbutamol does not affect athletic performance in asthmatic and non-asthmatic cyclists." British journal of sports medicine (2013): bjsports-2013.
• Norris, S. R., S. R. Petersen, and R. L. Jones. "The effect of salbutamol on performance in endurance cyclists." European journal of applied physiology and occupational physiology 73.3-4 (1996): 364-368.
• Weiler, John M., Teresa Layton, and Margaret Hunt. "Asthma in United States Olympic athletes who participated in the 1996 Summer Games." Journal of Allergy and Clinical Immunology 102.5 (1998): 722-726.