Why do I always wheeze while running?

Possible Asthma. Sometimes exercise can cause the smooth muscle surrounding the airways to be "twitchy" and reactive. This narrowing of the airway lumen can cause turbulence of airflow and lead to wheezing. This is referred to as exercise-induced bronchospasm and can be treated with a bronchodilator like albuterol.
May have. Excercise induced asthma....See doctor..