(both cases and controls) 1. patients requiring active ventilator support 2. anticoagulant/antiplatelet therapy (for those in the biopsy arm, see randomization schema. if clinically feasible, patients will be asked to hold their anticoagulants for the muscle biopsy after physician review), 3. recent gastrointestinal bleeding (\<3 months) 4. advanced organ diseases: congestive heart failure (nyha class 3 and 4), chronic obstructive pulmonary diseases (copd) (gold stage 3 and 4), chronic kidney disease (cr\>3), metastatic malignancy 5. medications that alter muscle protein metabolism except systemic corticosteroids 6. pregnancy 7. unwillingness/ inability to sign informed consent

(both cases and controls) 1. patients requiring active ventilator support 2. anticoagulant/antiplatelet therapy (for those in the biopsy arm, see randomization schema. if clinically feasible, patients will be asked to hold their anticoagulants for the muscle biopsy after physician review), 3. recent gastrointestinal bleeding (\<3 months) 4. advanced organ diseases: congestive heart failure (nyha class 3 and 4), chronic obstructive pulmonary diseases (copd) (gold stage 3 and 4), chronic kidney disease (cr\>3), metastatic malignancy 5. medications that alter muscle protein metabolism except systemic corticosteroids 6. pregnancy 7. unwillingness/ inability to sign informed consent

(both cases and controls) patients requiring active ventilator support anticoagulant/antiplatelet therapy (for those in the biopsy arm, see randomization schema. if clinically feasible, patients will be asked to hold their anticoagulants for the muscle biopsy after physician review), recent gastrointestinal bleeding (<3 months) advanced organ diseases: congestive heart failure (nyha class 3 and 4), chronic obstructive pulmonary diseases (copd) (gold stage 3 and 4), chronic kidney disease (cr>3), metastatic malignancy medications that alter muscle protein metabolism except systemic corticosteroids pregnancy unwillingness/ inability to sign informed consent

(both cases and controls) patients requiring active ventilator support anticoagulant/antiplatelet therapy (for those in the biopsy arm, see randomization schema. if clinically feasible, patients will be asked to hold their anticoagulants for the muscle biopsy after physician review), recent gastrointestinal bleeding (<3 months) advanced organ diseases: congestive heart failure (nyha class 3 and 4), chronic obstructive pulmonary diseases (copd) (gold stage 3 and 4), chronic kidney disease (cr>3), metastatic malignancy medications that alter muscle protein metabolism except systemic corticosteroids pregnancy unwillingness/ inability to sign informed consent

(both cases and controls) 1. patients requiring active ventilator support 2. anticoagulant/antiplatelet therapy (for those in the biopsy arm, see randomization schema. if clinically feasible, patients will be asked to hold their anticoagulants for the muscle biopsy after physician review), 3. recent gastrointestinal bleeding (<3 months) 4. advanced organ diseases: congestive heart failure (nyha class 3 and 4), chronic obstructive pulmonary diseases (copd) (gold stage 3 and 4), chronic kidney disease (cr>3), metastatic malignancy 5. medications that alter muscle protein metabolism except systemic corticosteroids 6. pregnancy 7. unwillingness/ inability to sign informed consent

(both cases and controls) 1. patients requiring active ventilator support 2. anticoagulant/antiplatelet therapy (for those in the biopsy arm, see randomization schema. if clinically feasible, patients will be asked to hold their anticoagulants for the muscle biopsy after physician review), 3. recent gastrointestinal bleeding (<3 months) 4. advanced organ diseases: congestive heart failure (nyha class 3 and 4), chronic obstructive pulmonary diseases (copd) (gold stage 3 and 4), chronic kidney disease (cr>3), metastatic malignancy 5. medications that alter muscle protein metabolism except systemic corticosteroids 6. pregnancy 7. unwillingness/ inability to sign informed consent