Asthma drug can boost sprint, strength performance in athletes, benefits greater when taken by mouth: Study
A type of asthma drug, known as ß2-agonists, can enhance sprint and strength performance in athletes who do not have the respiratory condition, according to a research team. The performance-enhancing qualities of ß2-agonists seem to be greater when taken by mouth rather than when inhaled, finds a review and pooled data analysis of the available evidence.
When the authors pooled data from 34 studies, the results showed that ß2-agonists acts as a class improved anaerobic exercise performance in those without asthma compared with a dummy treatment (placebo) by 5%. This is an improvement that would change the outcome of most athletic competitions, note researchers. Specifically, the improvements amounted to 3% for sprint performance and 6% for strength performance. But the impact was associated with dose size and administration route — tablet/syrup or inhaled, with the oral route more effective, say researchers in the study published in the British Journal of Sports Medicine.
The team includes experts from the Western Norway University of Applied Sciences, Sogndal, Vestlandet, Norway; and the Norwegian University of Sport and Physical Education, Oslo, Norway. The use of β2-agonists in sports is regulated by the World Anti-Doping Agency (WADA) due to possible performance-enhancing effects. Since 1972, the regulations regarding the use of inhaled β2-agonists in elite athletes have been revised on numerous occasions. According to the authors, it is, however, not clear if the ß2-agonists that have been officially approved for use by the WADA have the same effects as those that have been banned.
"We believe that the results from the present study should be of interest to the World Anti-Doping Agency and anyone who is interested in equal opportunities in competitive sports. It must be up to WADA and the governing bodies to conclude if the existing anti-doping rules regarding beta2-agonists should be revised, but we would recommend that WADA has criteria for the use of beta2-agonists in sports where anaerobic performance is essential for the outcome. The criteria should be based on objective tests for asthma and a doctor’s diagnosis," Dr Amund Riiser, Faculty of Teacher Education, Art and Sport, Western Norway University of Applied Sciences, tells MEA WorldWide (MEAWW).
"Beta2-agonists should not be prohibited in athletic completions, because they are a necessary treatment for athletes with asthma, but they should be regulated and controlled. The use of beta2-agonists in athletes should be controlled/regulated and limited to those with an asthma diagnosis documented with objective tests," Dr Riiser adds.
ß2-agonists relax the airways carrying oxygen to the lungs. They are recommended before exercise and for symptom relief in those with asthma, which is common among Olympic athletes. "Asthma is one of the world’s most common chronic diseases and affects people of all ages. Elite athletes, especially endurance athletes regularly performing heavily increased ventilation, have an increased risk of asthma."
"Asthma is the most common chronic disease in athletes participating in the Olympic Games. The gold standard for asthma therapy is inhaled glucocorticoids with inhaled β2-agonists pre-exercise and as a reliever of symptoms. But the use of inhaled ß2-agonists by elite athletes is highly controversial as athletes with asthma have consistently outperformed their peers who don't have the respiratory condition," write authors.
According to researchers, the potential performance-enhancing qualities of ß2-agonists have been the focus of numerous (often contradictory) studies and regulations as well as continuing controversy following recent anti-doping investigations involving world-class athletes. In light of the ongoing controversy, the team decided to analyze the effect of these drugs on anaerobic exercise performance.
This type of exercise requires a quick burst of energy at maximum effort for a short time and includes sprinting and weight-lifting. The authors looked at research databases looking for suitable clinical trials, published up to December 2019, and found 34 relevant studies, covering 44 different randomized controlled trials and involving a total of 472 participants.
"34 studies were included in the present meta-analysis. The studies include 44 different randomized and placebo-controlled comparisons with β2-agonists comprising 323 participants in crossover trials and 149 participants in parallel trials. In the overall analyses, ß2- agonists improved anaerobic performance by 5%, but the effect was related to the dose and administration route. Oral administration had a larger effect than inhalation even if both administration routes improved performance, and prohibited doses of ß2-agonists had a different effect than approved doses of ß2-agonists," the findings state.
In January this year, WADA updated its list of banned substances, which included all ß2-agonists except specific doses of inhaled salbutamol, formoterol, and salmeterol. When the analysis was further refined to a comparison of banned and approved ß2-agonists, the approved drugs did not boost anaerobic performance, while banned ß2-agonists did. But there was still a tendency towards an enhanced performance for approved ß2-agonists, and the effect was greater after several weeks of treatment, says the team. "This means that it is still uncertain whether approved doses improve anaerobic performance," say researchers.