Effects of intravenous N-acetylcysteine infusion on time to fatigue and potassium regulation during prolonged cycling exercise.

@article{Medved2004EffectsOI,
  title={Effects of intravenous N-acetylcysteine infusion on time to fatigue and potassium regulation during prolonged cycling exercise.},
  author={Ivan Medved and Malcolm J Brown and Andrew R. Bjorksten and Michael J. McKenna},
  journal={Journal of applied physiology},
  year={2004},
  volume={96 1},
  pages={
          211-7
        }
}
The production of reactive oxygen species in skeletal muscle is linked with muscle fatigue. This study investigated whether the antioxidant compound N-acetylcysteine (NAC) augments time to fatigue during prolonged, submaximal cycling exercise. Seven men completed a double-blind, crossover study, receiving NAC or placebo before and during cycling exercise, comprising 45 min at 70% of peak oxygen consumption (Vo2 peak) and then to fatigue at 90% Vo2 peak. NAC was intravenously infused at 125 mg… 
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NAC improved performance in well-trained individuals, with enhanced muscle cysteine and GSH availability a likely mechanism.

Influence of N-acetylcysteine administration on pulmonary O2 uptake kinetics and exercise tolerance in humans

Effects of N-acetylcysteine on respiratory muscle fatigue during heavy exercise

Effects of oral N-acetylcysteine on fatigue, critical power, and W′ in exercising humans

N-acetylcysteine alters substrate metabolism during high-intensity cycle exercise in well-trained humans.

It is suggested that NAC alters substrate metabolism and muscle fibre type recruitment during HIIE, which is detrimental to time-trial performance.

ffects of oral N-acetylcysteine on fatigue , critical power , and W ′ in exercising umans

It is demonstrated that oral NAC was successful in extending time to fatigue at 80% Pmax but not at higher work rates, and there were no significant differences in V̇O2 kinetics.

N‐Acetylcysteine infusion does not affect glucose disposal during prolonged moderate‐intensity exercise in humans

Unlike findings in mouse muscle ex vivo, NAC does not attenuate skeletal muscle glucose disposal or AMPK activation during moderate‐intensity exercise in humans.

Acute supplementation of N‐acetylcysteine does not affect muscle blood flow and oxygenation characteristics during handgrip exercise

It is concluded that acute NAC supplementation does not alter oxygen delivery during exercise in men and the underlying mechanisms are unknown.

Effect of N-acetylcysteine on cycling performance after intensified training.

Oral NAC supplementation improved cycling performance via an improved redox balance and promoted adaptive processes in well-trained athletes undergoing strenuous physical training.

N‐acetylcysteine attenuates the decline in muscle Na+,K+‐pump activity and delays fatigue during prolonged exercise in humans

It is confirmed that the antioxidant NAC attenuates muscle fatigue, in part via improved K+ regulation, and point to a role for ROS in muscle fatigue.
...

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