Premium
Effects of N‐acetylcysteine on glutathione oxidation and fatigue during handgrip exercise
Author(s) -
Matuszczak Yves,
Farid Mehran,
Jones Jeffrey,
Lansdowne Samme,
Smith Melissa A.,
Taylor Addison A.,
Reid Michael B.
Publication year - 2005
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.20385
Subject(s) - acetylcysteine , isometric exercise , glutathione , medicine , placebo , muscle fatigue , forearm , oxidative stress , hand strength , physical therapy , physical medicine and rehabilitation , grip strength , surgery , antioxidant , electromyography , chemistry , biochemistry , pathology , enzyme , alternative medicine
Fatigue of hand and forearm muscle groups can limit task performance by astronauts wearing space suits. Countermeasures to delay fatigue would therefore be useful to the space program. N‐acetylcysteine (NAC) has been shown to inhibit fatigue during other tasks so we tested its effects during handgrip exercise. Volunteers practiced isometric handgrip maneuvers until performance was reproducible over three successive sessions (baseline). Performance then was retested after ingesting NAC (150 mg.kg −1 ) or saline. Drug administration increased NAC and cysteine blood levels ( P < 0.001). Performance of sustained maximal efforts was unaffected. During repetitive submaximal efforts, NAC delayed fatigue (130% baseline) and inhibited glutathione oxidation. Saline did not alter glutathione status or performance of sustained maneuvers; repetitive task performance was increased by 15% ( P < 0.05), a placebo effect. These data indicate that NAC supports glutathione homeostasis in exercising humans and may delay muscle fatigue during repetitive handgrip exercise. Our findings support oxidative stress as a causal factor in human muscle fatigue and argue for larger translational studies to define NAC effects on human performance. Muscle Nerve, 2005