NAC Supplementation and Skeletal Muscle Performance

Democritus University of Thrace

Status: Completed

Conditions: Skeletal Muscle Performance; Intgracellular Signaling in Skeletal Muscle; Inflammatory Status; Skeletal Muscle Damage

Treatments: Dietary Supplement: n-acetylcysteine supplementation

Study type: Interventional

Funder types: Other

Identifiers

NCT01778309

CE-80739 (Other Identifier)

NACEXERCISE2011

Details and patient eligibility

About

In this investigation the investigators utilized NAC administration to foster GSH availability during an 8-day period following eccentric exercise-induced muscle damage in order to test our hypotheses: i) antioxidant supplementation does not disturb performance and adaptations induced by exercise-induced muscle injury and ii) redox status perturbations in skeletal muscle are pivotal for the regulation of muscle' inflammatory response and repair.

Full description

The major thiol-disulfide couple of reduced (GSH) and oxidized glutathione (GSSG) is a key-regulator of major transcriptional pathways regulating aseptic inflammation and recovery of skeletal muscle following aseptic injury. Antioxidant supplementation may hamper exercise-induced cellular adaptations.

Our objective was to examine how thiol-based antioxidant supplementation affects skeletal muscle's performance and redox-sensitive signalling during the inflammatory and repair phases associated with exercise-induced micro-trauma.In a double-blind, counterbalanced design, 12 men received placebo (PLA) or N-acetylcysteine (NAC, 20 mg/kg/day) following muscle-damaging exercise (300 eccentric contractions). In each trial, muscle performance was measured at baseline, post-exercise, 2h post-exercise and daily for 8 consecutive days. Muscle biopsies from vastus lateralis and blood samples were collected pre-exercise and 2h, 2d, and 8d post-exercise.

Enrollment: 20 patients

Sex: Male

Ages: 18 to 30 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

a) recreationally trained as evidenced by their maximal oxygen consumption levels (VO2max >45 ml/kg/min), b) were engaged in systematic exercise at least three times/week for ≥12 months), c) non-smokers, d) abstained from any vigorous physical activity during the study, e)abstained from consumption of caffeine, alcohol, performance-enhancing or antioxidant supplements, and medications during the study.

Exclusion criteria

a) a known NAC intolerance or allergy, b) a recent febrile illness, c) history of muscle lesion, d) lower limb trauma

Trial design

Primary purpose: Basic Science

Allocation: N/A

Interventional model: Single Group Assignment

Masking: Double Blind

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20 participants in 1 patient group

n-acetylcysteine/placebo supplementation

Experimental group

Description:

n-acetylcysteine supplementation, orally in three daily dosages, at 20 mg/kg/day, daily for eight days after exercise placebo, orally in three daily dosages, content: 500 mL drink that contained water (375 mL), sugar-free cordial (125 ml), and 2 g of low-calorie glucose/dextrose powder.

Treatment:

Dietary Supplement: n-acetylcysteine supplementation