A new study says that consuming caffeine within an hour of exercise can reduce the symptoms of exercise-induced asthma (EIA).
In the study, researchers at Indiana University found that 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.
Timothy Mickleborough, an associate professor in the Department of Kinesiology and co-author of the study, said no additional benefit was found when caffeine was combined with an albuterol inhaler.
The 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. Previous 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 was presented at the American College of Sports Medicine conference.