NAC Supplementation and Skeletal Muscle Performance
- Conditions
- Skeletal Muscle DamageSkeletal Muscle PerformanceInflammatory StatusIntgracellular Signaling in Skeletal Muscle
- Registration Number
- NCT01778309
- Lead Sponsor
- Democritus University of Thrace
- Brief Summary
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.
- Detailed 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.
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- Male
- Target Recruitment
- 20
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.
a) a known NAC intolerance or allergy, b) a recent febrile illness, c) history of muscle lesion, d) lower limb trauma
Study & Design
- Study Type
- INTERVENTIONAL
- Study Design
- SINGLE_GROUP
- Primary Outcome Measures
Name Time Method Change in reduced glutathione in blood one hour before exercise, 5 minutes post-exercise, 2 hours post-exercise, daily for 8 days post-exercise Concentration of reduced glutathione in red blood cells
Change in reduced glutathione in muscle one hour before exercise, 2 hours post-exercise, 2 days post-exercise, 8 days post-exercise concentration of reduced glutathione in quadriceps skeletal muscle group
Change in protein carbonyls in red blood cells and serum one hour before exercise, 5 minutes post-exercise, 2 hours post-exercise, daily for 8 days post-exercise concentration of protein carbonyls
Change in protein carbonyls in muscle one hour before exercise, 2 hours post-exercise, 2 days post-exercise, 8 days post-exercise protein carbonyl concentration in vastus lateralis skeletal muscle
Change in thiobarbituric acid reactive substances in red blood cells and serum one hour before exercise, 5 minutes post-exercise, 2 hours post-exercise, daily for 8 days post-exercise thiobarbituric acid reactive substances concentration in serum and red blood cells
Change in thiobarbituric acid reactive substances in muscle one hour before exercise, 2 hours post-exercise, 2 days post-exercise, 8 days post-exercise thiobarbituric acid reactive substances concentration in vastus lateralis skeletal muscle
Change in oxidized glutathione in red blood cells and blood one hour before exercise, 5 minutes post-exercise, 2 hours post-exercise, daily for 8 days post-exercise Concentration of oxidized glutathione in red blood cells and whole blood
Change in total antioxidant capacity in serum one hour before exercise, 5 minutes post-exercise, 2 hours post-exercise, daily for 8 days post-exercise Change in oxidized glutathione in muscle one hour before exercise, 2 hours post-exercise, 2 days post-exercise, 8 days post-exercise concentration of oxidized glutathione in vastus lateralis skeletal muscle
Change in catalase activity in red blood cells and serum one hour before exercise, 5 minutes post-exercise, 2 hours post-exercise, daily for 8 days post-exercise Change in glutathione peroxidase activity in red blood cells one hour before exercise, 5 minutes post-exercise, 2 hours post-exercise, daily for 8 days post-exercise Change in creatine kinase activity in plasma one hour before exercise, 5 minutes post-exercise, 2 hours post-exercise, daily for 8 days post-exercise Change in C-reactive protein in plasma one hour before exercise, 5 minutes post-exercise, 2 hours post-exercise, daily for 8 days post-exercise Change in macrophage infiltration in muscle one hour before exercise, 2 hours post-exercise, 2 days post-exercise, 8 days post-exercise Change in white blood cell count in blood one hour before exercise, 5 minutes post-exercise, 2 hours post-exercise, daily for 8 days post-exercise Change in neutrophil count in blood one hour before exercise, 5 minutes post-exercise, 2 hours post-exercise, daily for 8 days post-exercise Change in fatty acid binding protein in plasma one hour before exercise, 5 minutes post-exercise, 2 hours post-exercise, daily for 8 days post-exercise Change in cortisol concentration in blood one hour before exercise, 5 minutes post-exercise, 2 hours post-exercise, daily for 8 days post-exercise Change in testosterone concentration in plasma one hour before exercise, 5 minutes post-exercise, 2 hours post-exercise, daily for 8 days post-exercise Change in cytokine concentration in plasma one hour before exercise, 5 minutes post-exercise, 2 hours post-exercise, daily for 8 days post-exercise Measurement of IL-1β, IL-4, IL-6, TNF-α, IL-8, IL-10, IL-12p70 concentrations in plasma
Change in adhesion molecule concentration in blood one hour before exercise, 5 minutes post-exercise, 2 hours post-exercise, daily for 8 days post-exercise Measurement of ICAM-1, VCAM-1, sP-selectin, sE-selectin concentrations in plasma
Change in intracellular signalling proteins in muscle one hour before exercise, 2 hours post-exercise, 2 days post-exercise, 8 days post-exercise Measurement of phosphorylation levels of protein kinase B (Akt), mammalian target of rapamycin (mTOR), serine/threonine kinase (p70S6K), ribosomal protein S6 (rpS6), nuclear factor κB (NFκB), serine⁄threonine mitogen activated protein kinase (p38-MAPK) in vastus lateralis muscle.
Change in myogenic determination factor (MyoD) protein levels in muscle one hour before exercise, 2 hours post-exercise, 2 days post-exercise, 8 days post-exercise MyoD expression in vastus lateralis muscle
Change in tumor necrosis factor α in muscle one hour before exercise, 2 hours post-exercise, 2 days post-exercise, 8 days post-exercise Protein levels of TNF-α in vastus lateralis muscle
- Secondary Outcome Measures
Name Time Method Change in muscle function of knee extensor and flexor muscle one hour before exercise, 5 minutes post-exercise, 2 hours post-exercise, daily for 8 days post-exercise assessment of muscle peak and mean torque of knee extensors and flexors on an isokinetic dynamometer at 0, 90 and 180 degrees/sec
Body composition One day before exercise Assessment of percent (%) lean body mass.
Maximal aerobic capacity One day before exercise Assessment of maximal oxygen consumption, an indice of cardiovascular conditioning
Change in profile of dietary intake one hour before exercise, daily for 8 days post-exercise Assessment of dietary intake with emphasis on antioxidant element intake
Change in side effect occurence one hour before exercise, daily for 8 days post-exercise The prevalence of potential side-effects (such as headaches or abdominal pain or any other discomfort) was monitored using a subjective 0-10 side-effects scale on a daily bases by an unblinded investigator (for ethical reasons).
Trial Locations
- Locations (1)
Laboratory of Physical Education & Sport Performance
🇬🇷Komotini, Thrace, Greece
Laboratory of Physical Education & Sport Performance🇬🇷Komotini, Thrace, Greece