With both oral and intravenous administration, most side effects are associated with the initial bolus loading period. With intravenous infusion, "anaphylactoid" reactions are more common and potentially more serious than with oral administration. As a result, an intravenous loading protocol was developed by McKenna's research group specifically to safely study acute effects of NAC in skeletal muscle. In this protocol, subjects receive an initial bolus infusion of 125 mg/kg/h NAC for 15 minutes, followed by constant infusion at 25 mg/kg/h thereafter; this protocol is well-tolerated with minimal side effects. As no established protocol exists for the chronic infusion of NAC with the aim of improving skeletal muscle redox homeostasis and anabolic sensitivity during hospitalization in older adults, the investigators propose to administer NAC orally, to reduce the likelihood of anaphylactoid reactions, in 50 mg/kg boluses administered 3 times each day. Our rationale is as follows: 1) As opposed to the setting of acute acetaminophen toxicity, oxidative stress is not expected to develop suddenly during hospitalization-induced inactivity; thus, a more gradual approach to a plateau in systemic NAC levels should be satisfactory and should minimize the likelihood of NAC-induced side effects, 2) based on a recent study of NAC effects on exercise-induced oxidative stress, such an infusion should affect redox status in vivo, 3) the total NAC dose per day will be 150 mg/kg, which is approximately half of the total amount administered over the first 24 hours following acetaminophen overdose or in a previous study of NAC effects in healthy young controls (~320 mg/kg).