NAC Supplementation and Soccer Specific Performance

Effects of NAC Supplementation on Immune Function, Inflammatory and Performance Responses of Elite Soccer Players Participated in Three Repetitive Games.

In this investigation the investigators utilized NAC supplementation to boost GSH availability during an one-week-microcycle consisting of three soccer games, in order to test the hypotheses that: i) antioxidant supplementation may enhance the recovery of performance and physiological stress variables following multiple match-plays and ii) redox status perturbations are critical in regulating the inflammatory response and repair in skeletal muscle, following repetitive exercise-induced muscle injuries.

Study Overview

• Status: Completed
• Conditions: Skeletal Muscle Performance; Skeletal Muscle Damage; Exercise-induced Aseptic Inflammation; Antioxidant Status
• Intervention / Treatment: Dietary supplement: N-acetylcysteine; Dietary supplement: Placebo

Detailed Description

After exercise-induced muscle microtrauma the thiol/disulfide couple of reduced (GSH) and oxidized glutathione (GSSG) is a key regulator of important transcriptional pathways that control the inflammatory response and recovery of skeletal muscle.

The objective was to examine how thiol-based antioxidant supplementation affects the muscle damage, oxidative stress, inflammatory and immune responses, as well as the level of post-game fatigue and muscle's recovery kinetics in response to three soccer games within a week. Participants were randomly assigned to one of four groups: i) Experimental-NAC [EXP-NAC, N=10, participated in daily training sessions and three games and received NAC (20 mg/kg/day)], ii) Experimental-Placebo (EXP-Pla, N=10, participated in daily training sessions and three games and received Placebo), iii) Control-NAC [CON-NAC, N=10, participated in daily training sessions only and received NAC(20 mg/kg/day)] and iv) Control-Placebo (CON-Pla, N=10, participated in daily training sessions only and received Placebo). Blood samples were collected at baseline, post-games and daily during recovery. Performance was assessed at baseline and daily during recovery.

• Study Type: Interventional
• Enrollment (Actual): 40
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Greece
  • Tríkala, Greece, 42100
    • Exercise Biochemistry Laboratory, School of Physical Education & Sports Sciences, University of Thessaly

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 16 years to 26 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Male

Description

Inclusion Criteria:

• Participation at elite level (top three division leagues) of soccer competition for at least five years
• Abstained from consumption of performance-enhancing supplements, antioxidant supplements and medications (for at least 6 months before and during the study)
• Participation in at least six two-hour training sessions and one match per week
• Non-smokers

Exclusion Criteria:

• A known NAC intolerance or allergy
• A recent febrile illness
• History of muscle lesion
• Lower limb trauma
• Metabolic diseases

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: EXP-NAC; Participated in daily training sessions and three games, and supplemented daily with N-acetylcysteine, orally in three daily dosages (morning-midday-evening),for seven consecutive days.	Dietary supplement: N-acetylcysteine; Orally in three daily dosages (morning-midday-evening), at 20 mg/kg/day, for seven consecutive days.; Other Names: NAC
Experimental: EXP-Pla; Participated in daily training sessions and three games, and supplemented daily with Placebo, orally in three daily dosages (morning-midday-evening), for seven consecutive days.	Dietary supplement: Placebo; 500 mL drink that contained water (375 mL), sugar-free cordial (125 ml), and 2 g of low-calorie glucose/dextrose powder. Orally in three daily dosages (morning-midday-evening), for seven consecutive days.
Active Comparator: CON-NAC; Participated in daily training sessions only and supplemented daily with N-acetylcysteine, orally in three daily dosages (morning-midday-evening),for seven consecutive days.	Dietary supplement: N-acetylcysteine; Orally in three daily dosages (morning-midday-evening), at 20 mg/kg/day, for seven consecutive days.; Other Names: NAC
Active Comparator: CON-Pla; Participated in daily training sessions only and supplemented daily with Placebo, orally in three daily dosages (morning-midday-evening), for seven consecutive days.	Dietary supplement: Placebo; 500 mL drink that contained water (375 mL), sugar-free cordial (125 ml), and 2 g of low-calorie glucose/dextrose powder. Orally in three daily dosages (morning-midday-evening), for seven consecutive days.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in total antioxidant capacity in serum		At baseline and daily throughout the study, up to 11 days
Change in protein carbonyls in serum		At baseline and daily throughout the study, up to 11 days
Change in thiobarbituric acid reactive substances in serum		At baseline and daily throughout the study, up to 11 days
Change in reduced glutathione in red blood cells		At baseline and daily throughout the study, up to 11 days
Change in oxidized glutathione in red blood cells		At baseline and daily throughout the study, up to 11 days
Change in creatine kinase in activity in plasma		At baseline and daily throughout the study, up to 11 days
Change in white blood cell count in blood		At baseline and daily throughout the study, up to 11 days
Change in repeated sprint ability	Players' repeated sprint ability was assessed via a repeared sprint test. Each player performed 5 x 30 meters sprints interspersed by 25 seconds of active recovery. Sprint time was recorded by using infrared photoelectrical gates.	At baseline and daily throughout the study, up to 11 days
Change in high intensity running during the game	High intensity running (i.e. > 14km/h) during the games was monitored by utilizing high time-resolution GPS devices.	During games 1, 2 and 3

Secondary Outcome Measures

Outcome Measure	Time Frame
Change in blood lactate concentration during the game	During games 1, 2 and 3
Change in average heart rate during the game	During games 1, 2 and 3

Collaborators and Investigators

• Sponsor: University of Thessaly
• Investigators: Principal Investigator: IOANNIS G FATOUROS, Ph.D., UNIVERSITY OF THESSALY, SCHOOL OF PHYSICAL EDUCATION & SPORTS SCIENCES

Study record dates

Study Major Dates

• Study Start (Actual): April 1, 2016
• Primary Completion (Actual): July 1, 2016
• Study Completion (Actual): December 1, 2016

Study Registration Dates

• First Submitted: June 22, 2020
• First Submitted That Met QC Criteria: August 20, 2020
• First Posted (Actual): August 21, 2020

Study Record Updates

• Last Update Posted (Actual): August 21, 2020
• Last Update Submitted That Met QC Criteria: August 20, 2020
• Last Verified: August 1, 2020

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Inflammation; Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Anti-Infective Agents; Antiviral Agents; Protective Agents; Respiratory System Agents; Antioxidants; Antidotes; Free Radical Scavengers; Expectorants; Acetylcysteine; N-monoacetylcystine
• Other Study ID Numbers: NAC-SOCCER-2016