S-Acetyl Glutathione and Performance Recovery in Soccer

NCT07690124 | Not Yet Recruiting

• 1 other identifier: UTH-06/13.02.2026
• Study Type: interventional
• Target: 20
• Locations: 1 country
• Sites: 1

Brief Summary

Soccer players display elevated inflammatory and oxidative stress markers combined with reduced soccer specific performance over a 72-hour period. However, in modern soccer, players participate very often in 2 or 3 matches within a week, with a recovery period of 72 hours between successive matches, that is insufficient to restore skeletal muscle homeostasis and performance. Of note, reduced glutathione (GSH) levels, a tripeptide consisting of the amino acids cysteine, glycine and glutamic acid, are substantially reduced during the 72-hour recovery period after a match because of the trauma-related acute inflammatory and oxidative stress response. GSH availability is a crucial regulator of cellular redox status, affecting numerous intracellular and physiological processes such as redox signalling, immunoregulation and muscle metabolism. Indeed, enhanced GSH availability following muscle damaging exercise has been shown to be beneficial for skeletal muscle and performance recovery by mitigating the inflammatory and oxidative stress response. Thus, the enhancement of GSH availability through dietary interventions would be a promising strategy to accelerate skeletal muscle and performance recovery following a soccer game. S-Acetyl Glutathione (SAG) is a glutathione precursor with enhanced absorption kinetics due to chemical S-acetylation of the thiol group on the cysteinyl amino acid of GSH and oral administration of SAG has been shown to be more effective in restoring intracellular glutathione levels compared to oral glutathione. The aim of this study is to (i) perform a pharmacokinetic assessment of 200 mg/day vs 500 mg/day of SAG during a 7-day supplementation period (pre-loading) and (ii) to establish the pharmacodynamic effect of the two dosages at 24, 48 and 72h following a 90-minute official soccer match.

Conditions

Performance Recovery; Exercise-induced Oxidative Stress; Exercise-induced Inflammation

Keywords

S-Acetyl Glutathione; Glutathione; soccer; recovery

Outcome Measures

Primary Outcomes (13)

• Change in creatine kinase levels

  Creatine kinase concentration will be measured in serum using a Clinical Chemistry Analyzer

  Day 1, day 7, day 9, day 10 and day 11

• Change in myoglobin levels

  Myoglobin concentration will be measured in serum using a Clinical Chemistry Analyzer

  Day 1, day 7, day 9, day 10 and day 11

• Change in reduced glutathione

  Reduced glutathione will be photometrically determined in red blood cell lysates using a spectrophotometer

  Day 1, day 7, day 9, day 10 and day 11

• Change in oxidized glutathione

  Oxidized glutathione will be photometrically determined in red blood cell lysates using a spectrophotometer

  Day 1, day 7, day 9, day 10 and day 11

• Change in glutathione reductase activity

  Glutathione reductase activity will be photometrically determined in red blood cell lysates using a spectrophotometer

  Day 1, day 7, day 9, day 10 and day 11

• Change in glutathione peroxidase activity

  Glutathione peroxidase activity will be photometrically determined in red blood cell lysates using a spectrophotometer

  Day 1, day 7, day 9, day 10 and day 11.

• Change in catalase activity

  Catalase activity will be photometrically determined in red blood cell lysates using a spectrophotometer

  Day 1, day 7, day 9, day 10 and day 11

• Change in superoxide dismutase activity

  Superoxide dismutase activity will be photometrically determined in red blood cell lysates using a spectrophotometer

  Day 1, day 7, day 9, day 10 and day 11

• Change in maximal voluntary isometric contraction

  Maximal voluntary isometric contraction will be assessed at a 60o knee joint angle, in both dominant and non-dominant limb, using an isokinetic dynamometer

  Day 1, day 9, day 10 and day 11

• Change in maximal peak torque

  Maximal concentric and eccentric peak torque at 60o/s of the knee extensors and flexors in both dominant and non-dominant limb, will be assessed on an isokinetic dynamometer

  Day 1, day 9, day 10 and day 11

• Change in jumping performance

  Countermovement jump and drop jump performance will be tested using an optical measurement system consisting of a transmitting and receiving bar

  Day 1, day 9, day 10 and day11

• Change in repeated sprint ability

  Repeated sprint ability will be assessed by performing 5x25 m sprints interspersed by a 25-seconds recovery period using infrared photocells

  Day 1, day 9, day 10 and day 11

• Change in delayed onset muscle soreness (DOMS)

  DOMS will be assessed using a 10-scale visual analogue scale

  Day 1, day 9, day 10 and day 11

Secondary Outcomes (10)

• Change in total distance covered

  Daily throughout the 11-day experimental period

• Change in internal load

  Daily throughout the 11-day experimental period

• Change in dietary intake

  Daily throughout the 11-day experimental period

• Change in time spent in moderate-to-vigorous physical activity

  Daily throughout the 11-day experimental period

• Change in distance covered with high-intensity running

  Daily throughout the 11-day experimental period

Study Arms (3)

SAG-200 Trial

EXPERIMENTAL

Oral administration of S-Acetyl Glutathione (SAG)

Dietary Supplement: 200 mg S-Acetyl Glutathione

SAG-500 Trial

EXPERIMENTAL

Oral administration of S-Acetyl Glutathione (SAG)

Dietary Supplement: 500 mg S-Acetyl Glutathione

Placebo Trial

PLACEBO COMPARATOR

Oral administration of placebo

Dietary Supplement: Placebo Supplementation

Interventions

200 mg S-Acetyl Glutathione DIETARY_SUPPLEMENT

Participants will be supplemented daily with 200 mg of S-acetyl glutathione, orally, over the 11-day experimental period.

SAG-200 Trial

500 mg S-Acetyl Glutathione DIETARY_SUPPLEMENT

Participants will be supplemented daily with 500 mg of S-acetyl glutathione, orally, over the 11-day experimental period.

SAG-500 Trial

Placebo Supplementation DIETARY_SUPPLEMENT

Participants will be supplemented daily with placebo, orally, over the 11-day experimental period.

Placebo Trial

Eligibility Criteria

• Age: 19 Years - 29 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• participation at elite (top three division leagues) for ≥ 4 years
• no recent history of febrile illness, musculoskeletal problems and metabolic diseases
• no consumption of medications and performance-enhancing supplements (including anti-inflammatory, antioxidants, vitamins and multivitamin supplements) for at least 6 months prior to the study
• participation in at least 5 training sessions and 1 match per week
• non-smokers

You may not qualify if:

• musculoskeletal injury
• consumption of medication and performance-enhancing supplements
• illness during the course of the study
• loss of follow-up measurements

Sponsors & Collaborators

• University of Thessaly: lead
• Lesaffre International: collaborator

Study Sites (1)

Department of Physical Education and Sport Science, University of Thessaly

Trikala, Karies, 42100, Greece

Location

Study Officials

• Dimitrios Draganidis, PhD

  University of Thessaly, Department of Physical Education and Sport Science

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Dimitrios Draganidis, PhD

CONTACT

+30 2431047078; ddraganidis@uth.gr

Athanasios Poulios, PhD

CONTACT

+30 2431047053; athanpoul@gmail.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: OTHER
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor

Study Record Dates

• First Submitted: June 9, 2026
• First Posted: July 8, 2026
• Study Start (Estimated): September 1, 2026
• Primary Completion (Estimated): December 20, 2026
• Study Completion (Estimated): January 20, 2027
• Last Updated: July 8, 2026

Record last verified: 2026-05

Data Sharing

• IPD Sharing: Will not share

Locations

GR (1)