The prevalence of asthma is higher in elite athletes than in the general population and the risk of developing asthmatic symptoms is highest in endurance athletes and swimmers. Asthma also seems particularly widespread in winter-sport athletes such as cross-country skiers, where the drying effects of cold air on the upper respiratory tract may be a factor.

The most common treatment for asthmatic athletes is the inhalation of beta(2)-agonists via the use of an inhaler, which are prohibited by the World Anti Doping Agency (WADA) unless a therapeutic use exemption has been granted, in which case formoterol, salbutamol, salmeterol and terbutaline can be used. Recently, however, some researchers and sports administrators have questioned whether even these should be allowed, fearing that they might offer an unfair advantage, even in asthmatic athletes. But a new meta-study (a study looking at all the studies in a particular research area) carried out by German researchers indicates that these fears are unfounded.

In 17 of 19 randomised placebo-controlled trials in non-asthmatic competitive athletes included in the meta-study, the performance-enhancing effects of the inhaled beta(2)-agonists formoterol, salbutamol, salmeterol and terbutaline could not be proved. This was particularly true for endurance performance, anaerobic power and strength performance. Moreover, in three of four studies, even doses well above the herapeutic dose of salbutamol (800-1,200mcg) had no ergogenic effect whatsoever. This was in contrast to oral administration of salbutamol, which does seem to be able to improve muscle strength and endurance performance.

The researchers concluded however that [on the evidence of their study], ‘there appears to be no justification to prohibit inhaled beta(2)-agonists on the basis of any ergogenic effects they might confer’.

Sports Med 2007; 37(2):95-102