AbstractAssessing changes in functional exercise capacity is highly relevant in the treatment of people with Chronic Obstructive Pulmonary Disease (COPD), as lung function is often static. In Denmark, most people with COPD are followed in general practice where traditional functional tests, like six-minute walk test, require too much time and space. Therefore, there is an urgent need for a quick functional exercise capacity test that can be performed in a limited setting, such as general practice. This study aimed to identify a quick test to measure functional exercise capacity in people with COPD and identify which factors could affect the implementation of such a test in general practice. A mixed method feasibility study composed of a literature review and qualitative interviews was used. Quick functional tests for people with COPD were identified and evaluated through the COSMIN methodology. For the interviews, 64 general practices were included, and 50 staff members and 14 general practitioners (GPs) participated in the interviews. Responses were categorized and thematically analyzed. The 1 min sit-to-stand-test (1 M STST) was found suitable for a general practice setting. The COSMIN methodology rated it “sufficient” in reliability (ICC 0.90–0.99), measurement error (MID 2.5–3), construct validity and responsiveness (AUC 0.72), and found a moderate to strong correlation in criterion validity (r = 0.4–0.75). Several GPs wished for a quick functional test and emphasized evidence, information, and limitations as essential when deciding on implementation. Other factors identified included time, other tests, and economy. 1 M STST is a valid test to assess functional exercise capacity in people with COPD. The test is quick and can easily be performed in a standard consultation, and several GPs wished for such a test.