A study from a University of Oregon researcher and published in the Journal of Applied Physiology, finds that antihistamines may inhibit muscle growth and recovery from endurance exercise.
While histamine is commonly associated with allergic reactions ranging from a runny nose to anaphylaxis, its place in the body goes beyond that, said study author John Halliwill, a professor of human physiology at UO. It helps the body heal injuries from scrapes to the tiny muscle fiber tears that occur with strenuous exercise.
“Histamine gets released from injured tissue and it plays a primary role in bringing more blood flow to that area, making the blood vessels leak a bit more so that the immune cells can get to where they need to get to repair the injuries,” he told KLCC.
Study participants were split into two groups: a control and a group that took a dose of fexofenadine–a generic of the brand name Allegra–that is roughly triple the over-the-counter dosage. They also took ranitidine, a drug that helps with another histamine response, heartburn and indigestion.
Participants completed 21 endurance training sessions over the course of six weeks, being given either the drugs or placebo afterwards. The control group outperformed those who took the drug at peak power output.
Halliwill said he would like to see further research done to more closely examine what smaller doses do both for allergies and athletic performance.
“We know that allergy symptoms themselves are really disruptive for training and performance,” he said. “So doing some comparisons of how bad it is to suffer the allergies versus taking the minimally needed level of antihistamines to be able to combat that discomfort and perform better without getting into these higher doses.”
Halliwill said he's also curious to test the reaction of antihistamines in non-endurance forms of exercise such as high intensity or strength-based workouts.
