• Change from baseline quality of life at 12 weeks: King's Brief Interstitial Lung Disease Questionnaire (K-BILD) [ Time Frame: baseline and 12 week follow-up ]
  Quality of life will be measured with King's Brief Interstitial Lung Disease Questionnaire (K-BILD). It is a 15-item validated questionnaire assessing health status in patients with an interstitial lung disease. Questions are related to three domains: breathlessness and activities, psychological aspects, and chest symptoms. Each question has 7 possible answers. The questionnaire has a scale from 0 - 100, in which 100 means highest quality of life.
• Change in physical capacity [ Time Frame: baseline and 12 week follow-up ]
  Physical capacity will be measured by the 6 miuntes walking test
• Feasibility of a yoga class in patients with fibrosing interstitial lung diseases: focus group interview [ Time Frame: 12 week follow-up ]
  Evaluation of the study by a focus group interview
• Change from baseline quality of life at 12 weeks: Hospital Anxiety and Depression Scale (HADS) [ Time Frame: baseline and 12 week follow-up ]
  Quality of life will be measured with the Hospital Anxiety and Depression Scale (HADS). It is a 14-item questionnaire, 7 items are related to depression and 7 items are related to anxiety. Each question has 4 different answer options, each scored from 0-3. Scores are summed up for each field (depression or anxiety) with 0 points as lowest possibility and 21 scores as highest (0-7 = normal, 8-10 = borderline abnormal, and 11-21 = abnormal).
• Change from baseline quality of life at 12 weeks: Interstitial Lung Disease Anxiety-questionnaire [ Time Frame: baseline and 12 week follow-up ]
  Quality of life will be measured with Interstitial Lung Disease Anxiety-questionnaire. This is a 37-item questionnaire with 5 answer possibilities for each question (never, rare, sometimes, often, always). Total scores are a sum of all questions. Lowest score = 0, highest score = 136. The higher the score the better is the patients' quality of life.
• Expectations of study by participants [ Time Frame: baseline ]
  Evaluation of the study by a focus group interview

• Change from baseline quality of life at 12 weeks [ Time Frame: baseline and 12 week follow-up ]
  Quality of life will be measured with K-BILD-questionnaire
• Change in physical capacity [ Time Frame: baseline and 12 week follow-up ]
  Physical capacity will be measured by the 6 miuntes walking test
• Feasibility of a yoga class in patients with fibrosing interstitial lung diseases [ Time Frame: 12 week follow-up ]
  Evaluation of the study by a focus group interview
• Change from baseline quality of life at 12 weeks [ Time Frame: baseline and 12 week follow-up ]
  Quality of life will be measured with HADS-questionnaire
• Change from baseline quality of life at 12 weeks [ Time Frame: baseline and 12 week follow-up ]
  Quality of life will be measured with ILD-questionnaire
• Expectations of study by participants [ Time Frame: baseline ]
  Evaluation of the study by a focus group interview

Fibrosing interstitial lung diseases are characterized by loss of lung function, which leads to a decrease in quality of life and physical capacity. Several studies have shown an increase in quality of life and physical capacity after increasing physical activity in patients. There is evicence that yoga has a positive influence in patients with chronic obstructive pulmonary diseases, but so far, studies examining the effect of yoga in patients with fibrosing interstitial lung diseases are missing.

Study aims are to determine the feasibilty of this study, and to determine the effects of yoga to patients' quality of life and physical capacity.

Twenty patients with a fibrosing interstitial lung disease will be recruited and randomly assigned to the intervention or control group. Several questionnaires regarding quality of life will be conducted. Furthermore, the 6 minutes walking test, a lung function test and a biomarker analysis will be conducted at baseline and follow-up. The intervention group will participate in a 12 week yoga class, whereas the controll group will not participate. Yoga classes will be offered to the control group after the study.

In addition, focus group interviews will be conducted at baseline and follow-up with the intervention group.

Patients with a fibrosing interstitial lung disease will be recruited. In total 20 patients will be recruited, 10 for the intervention group and 10 for the control group.

The Intervention group will participate in a 12 week yoga class with classes twice a week for about 1 hour. The control group will not participate in a yoga class.

At baseline all patients will conduct a 6 minutes walking test, a lung function test, several surveys to measure health related quaility of life (King's Brief Interstitial Lung Disease Questionnaire (K-BILD), Hospital Anxiety and Depression Scale (HADS), Interstitial Lung Disease Anxiety questionnaire), and some blood will be drawn for biomarker analysis.

Furthermore, participants in the Intervention group will participate in two focus group interviews, one at baseline and the second one at 12 week follow-up.

• Fibrosing Interstitial Lung Diseases
• Idiopathic Pulmonary Fibrosis

• Experimental: Intervention group
  Intervention will be a 12 week yoga class
  Intervention: Other: 12 week yoga class
• No Intervention: Control group
  Control group will not participate in the 12 week yoga class but will participate in Surveys, 6 minute walking test, lung function test, and biomarker analysis. Furthermore, they will be offered a yoga class after the study.

Inclusion Criteria:

• ability to understand study and study procedure
• diagnosis of fibrosing interstitial lung disease
• Age: > 18 years
• Ability to consent

Exclusion Criteria:

• Forced Vital Capacity < 50%
• Oxygen therapy
• diagnosis of pulmonary hypertension
• participant does not understand the study
• pulmonary infection within the last 4 weeks
• acute exacerbation within the last 4 weeks
• other respiratory decline within the last 4 weeks
• co-morbidities which make yoga training impossible