If you find that your body becomes a fountain of phlegm when you go running, you're not alone. In fact, major phlegm action is such a common occurrence that runners devote whole blogs to the etiquette of getting rid of it. If you would rather not have to deal with phlegm at all, understanding more about respiratory congestion and exercise could help you find a solution.
Read More: What Is the Right Way to Breath When Running
Cold or Dry Air
Nasal airways and the trachea warm and humidify the air to make it easier for the lungs to pump oxygen into your system. Air that is very cold, very dry or both may give the airways' filtering mechanisms, the cilia, more than they can handle. This, in turn, can trigger an immune response that prompts the secretion of mucus. To prevent this from occurring — or, at least, slow it down a little — wearing a scarf or face mask to pre-warm the air that you breathe.
Allergies are one of the most likely triggers for phlegm production when running. It's quite possible that you don't suffer much from allergies under normal conditions, but running brings on the mucus. That could be because running increases the volume of air you circulate in and out of your respiratory system, so any sensitivities you have are likely to be revealed. If the air contains pollen, dust, mold or other contaminants such as particulate solution, you get the news in the form of phlegm.
Antihistamines may provide relief, especially the non-drowsy formulations such as Zyrtec, Allegra or Claritin (Benadryl, may make it hard to stay awake through your run). They should be taken at least one hour before running. Wearing a surgical mask or covering your nose and mouth with a scarf may also help.
Asthma and Exercise
Asthma is an inflammation of the airways and lungs that can cause difficulty breathing. Mucus, which is a frequent symptom of asthma, is part of what makes it harder to get your breath during an attack.
If you already have asthma, running can definitely make it worse. Exposure to allergens as well as cold or dry air can trigger asthma for many, but vigorous exercises such as running can also cause asthma in people who don't otherwise experience it. This is called exercise-induced asthma or bronchoconstriction.
Asthma medication is sold over the counter both in pill and inhaler form, but if the problem is chronic or severe, an allergist may prescribe a steroidal anti-inflammatory inhaler, in addition to a rescue inhaler. If you have been prescribed a short-acting inhaler, using it a few minutes before running may help prevent phlegm, as well as asthma.
Another method for desensitizing yourself to environmental triggers is nasal irrigation. It involves flushing the nasal passages with a salt water solution. Nasal irrigation also flushes phlegm-invoking pollen and other irritants out of your nasal passages after your run is over.
Read More: Long Distance Running Breathing Techniques