Exercise is an important clinical feature in cystic fibrosis. Better exercise capacity has been associated with better patient outcomes and quality of life. Exercise-induced bronchospasm is a condition, often associated with asthma, which may make exercise difficult. The role that exercise-induced bronchospasm has in people with cystic fibrosis is unknown. This study is designed to determine how often exercise-induced bronchospasm occurs in cystic fibrosis.

We anticipate that Visit 1 will take approximately three hours. This will include obtaining informed consent, completing baseline demographic and quality of life questionnaires, brief physical exam, measuring exhaled nitric oxide level, skin allergy testing, obtaining blood and sputum samples, and performing pulmonary function testing before and after bronchodilators.

Visit 2 will take approximately two and one-half hours. This will include performing Eucapnic Voluntary Hyperventilation, measuring exhaled nitric oxide levels, and obtaining blood and sputum samples.

Visit 3 will take approximately two and one-half hours. This will include performing Cardiopulmonary exercise testing followed by serial spirometry, measuring exhaled nitric oxide levels, and obtaining blood and sputum samples.

Inclusion Criteria:

1. Males and females with confirmed diagnosis of Cystic Fibrosis:

   • 2 positive sweat chloride tests (or)
   • genetic testing

2. Age 12 years and older

3. Baseline FEV1 ≥70% predicted

4. Clinically stable over past 28 days:

   • no change in chronic respiratory symptoms
   • no need for antibiotics other then chronic maintenance therapies
   • no need for oral steroids
   • no increased use of bronchodilators

5. Visit 1 FEV1 within 10% of baseline

Exclusion Criteria:

1. History of Allergic Bronchopulmonary Aspergillosis (ABPA)
2. Chronic airway colonization with Burkholderia cepacia (defined as 2 or more prior positive sputum or BAL cultures)
3. Pregnancy
4. Chronic oral corticosteroid use
5. Febrile illness within two weeks of Visit 1
6. Unable to provide consent (patients under age of 18 will require both parental consent AND patient assent)
7. Current cigarette smoking, cessation of smoking within 6 weeks of Visit 1, or more than 10 pack-years of prior smoking

Forty patients with cystic fibrosis and mild lung disease (defined by FEV1≥ 70% predicted), age 12 years and older, are our target enrollments.