As defined by Drugs.com, phlegm is a type of mucus, traditionally expelled from the mouth. While phlegm can be undesirable at any time, it is especially distressing during a run. To avoid phlegm during exercise, runners should be sure to maintain adequate hydration, consider allergic reactions, and limit mouth and nose exposure in cold weather. Those who do not experience beneficial results with these techniques should consult with an experienced health care professional.
Maintain adequate hydration. According to the National Institute of Health, maintaining adequate hydration is key when it comes to limiting the development of thick, sticky mucus. US News says runners should drink at least half their body weight in ounces per day -- or around 100 ounces of liquid for a 200-pound individual. These fluid requirements may be greater in very warm climates, or when water losses through perspiration are increased.
Avoid allergy-causing compounds. Monterey County Herald states that runners who develop mucus may be suffering from a specific type of allergic reaction. This reaction may be related to the consumption of certain foods, medications or even substances in the air. Keeping a diary of foods eaten and medications used on specific days can be useful when it comes to identifying the causes of mucus during a run.
Limit mouth and nose exposure in cold weather. The American College of Sports Medicine reports that cold weather can sometimes lead to the sudden shock of the airways, resulting in the production of significant amounts of mucus. Runners who live in northern climates should consider the use of a scarf or neck gaiter when exercising outdoors in inclement weather. Scarves and neck gaiters can be stuffed in a pocket or shirt sleeve if temperatures rise and protection is no longer a necessity.
Consult an experienced health care professional. In some cases, runners who develop phlegm during physical activity are actually suffering from a specific medical condition -- and if diagnosed quickly, may experience a complete recovery. Talk with friends and family members to identify a qualified medical provider who is experienced in the treatment of this condition. Though it can be embarrassing to discuss phlegm with an outsider, it may be crucial for the promotion of optimal health.