Fish Oil and HMB Supplementation in COPD

Inclusion criteria * Ability to walk, sit down and stand up independently * Ability to lie in supine or slightly elevated position for 8.5 hours * Age 45 - 100 * Clinical diagnosis of COPD, including moderate to very severe chronic airflow limitation, and an FEV1 \< 70% of reference FEV1 (GOLD II-III). If subjects are on β2 agonists, only those subjects with \<10% improvement in FEV1 will be included. * Clinically stable condition and not suffering from a respiratory tract infection or exacerbation of their disease (defined as a combination of increased cough, sputum purulence, shortness of breath, systemic symptoms such as fever, and a decrease in FEV1 \> 10% compared with values when clinically stable in the preceding year) at least 4 weeks prior to the first test day * Shortness of breath on exertion * Willingness and ability to comply with the protocol, including: * Refraining from intense physical activities (72h) prior to each study visit * Adhering to fasting state and no smoking from 10 pm ± 2h onwards the day prior to each study visit Exclusion Criteria * Participants 86 and older that fail to get physician approval * Established diagnosis of malignancy * Established diagnosis of Insulin Dependent Diabetes Mellitus * History of untreated metabolic diseases including hepatic or renal disorder * Presence of acute illness or metabolically unstable chronic illness * Recent myocardial infarction (less than 1 year) * Any other condition according to the PI or nurse…