Caffeine reduces symptoms of exercise-induced asthma
An Indiana University study found that the ingestion of caffeine within an hour of exercise can reduce the symptoms of exercise induced asthma (EIA).
A large dose -- 9 milligrams of caffeine per kilogram of body weight -- was as effective as the use of an albuterol inhaler, which is commonly used to treat or prevent exercise-induced asthma. Smaller amounts of caffeine -- for example, 3 and 6 milligrams of caffeine per kilogram of body weight -- also reduced the wheezing, coughing and other symptoms of EIA.
The average cup of coffee contains around 80 to 135 milligrams of caffeine.
Timothy Mickleborough, an associate professor in the Department of Kinesiology and co-investigator of the study, said no additional benefit was found when caffeine was combined with an albuterol inhaler. Mickleborough and his research colleagues have been investigating the efficacy of a number of nutritional factors, and his research to date has shown that a diet high in fish oil and antioxidants and low in salt has the potential to reduce the severity of EIA and perhaps reduce the reliance on pharmacotherapy. This is especially important since prolonged use of daily medications can result in reduced effectiveness, and there is growing concern about the potential side effects of inhaled corticosteroid use.
With EIA, vigorous exercise triggers an acute narrowing of the airway afterward, making breathing difficult. Around 80 percent of people with asthma have this condition, also called exercise-induced bronchoconstriction. EIA also is found in an estimated 10 percent or more of elite athletes and as much as 10 percent of the general population without asthma.
- Background: The caffeine study involved 10 asthmatic subjects who also had EIA, in a randomized, double-blind double-dummy crossover study. They ingested 3, 6, or 9 milligrams of caffeine per kilogram of body weight or a placebo an hour before running on a treadmill. Pulmonary function tests were conducted 15 minutes before the a eucapnic voluntary hyperpnea challenge (a surrogate for an exercise challenge) and then again 1, 5, 10, 15 and 30 minutes afterward.
For someone weighing 150 pounds, 3 to 9 milligrams of caffeine per kilogram of body weight equals around 205 to 610 milligrams of caffeine. Earlier research has found that caffeine can reduce the symptoms of EIA. This study extends this earlier work and is the first to examine any synergistic effect of caffeine use along with an albuterol inhaler.
The study, "Comparative and Synergistic Effects of Caffeine and Albuterol on The Severity of Exercise-Induced Bronchoconstriction," was presented during the Respiratory Session on Friday, May 29. Co-authors include lead author Timothy A. VanHaitsma, now at the University of Utah; Martin R. Lindley, Loughborough University, United Kingdom; and David Koceja and Joel Stager, IU's Department of Kinesiology.
To read more articles from the Department of Kinesiology in the School of Health, Physical Education and Recreation, visit http://newsinfo.iu.edu/cat/page/normal/356.html.
