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Performance RecoveryNCT07690124

S-Acetyl Glutathione and Performance Recovery in Soccer

A study testing 200 mg S-Acetyl Glutathione and 500 mg S-Acetyl Glutathione in people with Performance Recovery and Exercise-induced Inflammation, run by University of Thessaly at 1 site in Greece.

Not yet recruiting

Opening soon. The study is approved but enrolment has not started yet. Sites may already take enquiries.

Sites and contacts
Official record
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Trial 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… Read more about this study

Who is it for?
Ages 19 to 29 yearsHealthy volunteers can take part
What is being tested?
200 mg S-Acetyl Glutathione and 500 mg S-Acetyl Glutathione
Type of treatment
Pill or oral medicine
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
20 participants
Where
1 siteGreece
Study dates
1 Sep 2026to 20 Jan 2027
Phase
Interventional
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 19 to 29 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • 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

Who cannot join

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

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

Dimitrios Draganidis, PhD contact

+30 2431047078

ddraganidis@uth.gr

Athanasios Poulios, PhD contact

+30 2431047053

athanpoul@gmail.com

Greece1 site
  • Department of Physical Education and Sport Science, University of Thessaly

    Trikala, Karies, 42100

    Ioannis G Fatouros, PhD, +30 2431047047, ifatouros@uth.gr

    Athanasios Z Jamurtas, PhD, +30 24310 47054, ajamurt@uth.gr

Other trials in Greece

About this study

Official title: Pharmacodynamics & Pharmacokinetics Study of S-Acetyl Glutathione in Highly Trained Soccer Players

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.

Read the detailed description

Following baseline testing [including assessment of anthropometrics, body composition (via DXA instrumentation) and physical performance (cardiorespiratory fitness, drop jump and countermovement jump performance, repeated sprint anility, isokinetic peak torque)], 20 well-trained, soccer players will participate in three trials, receiving daily (i) 200 mg SAG, (ii) 500 mg SAG or (iii) Placebo, according to a randomized, double-blind, crossover, repeated-measures design. The duration of each trial will be 11 days, including a 7-day pre-loading period (days 1 -7), a match day (day 8) and 3 consecutive recovery days after the match (days 9-11). Between trials a 3-week washout period will be implemented.

Pre-loading period: During the 7-day pre-loading period players will participate daily in training sessions according to a soccer-specific weekly training schedule, while receiving the respective supplement. Blood samples will be collected on day 1 and day 7 while daily nutrient intake (via 7-day diet recalls), physical activity level (via accelerometry) and training load (via global positioning system instrumentation during training sessions) will be monitored daily.

Match day: On match day, players will participate in an official 90-min soccer match. Field activity (total distance, average and maximum speed, high intensity running, high speed running, accelerations, decelerations) and heart rate (mean and maximum heart rate) will be continuously monitored using global positioning system (GPS) and heart rate monitors, respectively.

Recovery days: During the 3-day recovery period after the match, players will participate daily in (i) morning testing sessions and (ii) training sessions in the evening. Testing sessions will include blood sampling and performance measurements including drop jump and countermovement jump performance, repeated sprint anility, isokinetic peak torque and muscle soreness (DOMS). Dietary intake (via a 3-day diet recalls), physical activity level (via accelerometry) and training load (via GPS instrumentation during training sessions) will be monitored daily.

Being tested
200 mg S-Acetyl Glutathione, 500 mg S-Acetyl Glutathione, Placebo Supplementation
Keywords
S-Acetyl Glutathione, Glutathione, soccer, recovery

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • 200 mg S-Acetyl GlutathioneDietary supplement

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

  • 500 mg S-Acetyl GlutathioneDietary supplement

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

  • Placebo SupplementationDietary supplement

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

Study groups in NCT07690124
Study groupRoleWhat they receive
SAG-200 TrialExperimentalOral administration of S-Acetyl Glutathione (SAG)
Receives: Dietary Supplement: 200 mg S-Acetyl Glutathione
SAG-500 TrialExperimentalOral administration of S-Acetyl Glutathione (SAG)
Receives: Dietary Supplement: 500 mg S-Acetyl Glutathione
Placebo TrialPlacebo comparatorOral administration of placebo
Receives: Dietary Supplement: Placebo Supplementation

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Change in creatine kinase levels

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

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

  2. Change in myoglobin levels

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

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

  3. Change in reduced glutathione

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

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

  4. Change in oxidized glutathione

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

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

  5. Change in glutathione reductase activity

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

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

  6. Change in glutathione peroxidase activity

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

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

  7. Change in catalase activity

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

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

  8. Change in superoxide dismutase activity

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

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

  9. 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

    Measured: Day 1, day 9, day 10 and day 11

  10. 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

    Measured: Day 1, day 9, day 10 and day 11

  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

    Measured: Day 1, day 9, day 10 and day11

  12. 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

    Measured: Day 1, day 9, day 10 and day 11

  13. Change in delayed onset muscle soreness (DOMS)

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

    Measured: Day 1, day 9, day 10 and day 11

Secondary outcomes (10)
  1. Change in total distance covered

    Total distance (km) covered during training and match play will be monitored using Global Positioning System (GPS)

    Measured: Daily throughout the 11-day experimental period

  2. Change in internal load

    Heart rate during training sessions and the match will be monitored using heart rate monitors

    Measured: Daily throughout the 11-day experimental period

  3. Change in dietary intake

    Dietary intake will be assessed using diet recalls

    Measured: Daily throughout the 11-day experimental period

  4. Change in time spent in moderate-to-vigorous physical activity

    The time (minutes) spent in moderate-to-vigorous physical activity on a daily basis will be monitored using accelerometers

    Measured: Daily throughout the 11-day experimental period

  5. Change in distance covered with high-intensity running

    Distance (km) covered with high-intensity running during training and match play will be monitored using Global Positioning System (GPS)

    Measured: Daily throughout the 11-day experimental period

  6. Change in distance covered with sprinting

    Distance (km) covered with high-intensity sprinting during training and match play will be monitored using Global Positioning System (GPS)

    Measured: Daily throughout the 11-day experimental period

  7. Change in accelerations

    The number of accelerations performed during training and match play will be monitored using Global Positioning System (GPS)

    Measured: Daily throughout the 11-day experimental period

  8. Change in decelerations

    The number of decelerations performed during training and match play will be monitored using Global Positioning System (GPS)

    Measured: Daily throughout the 11-day experimental period

  9. Change in total step count

    The total number of steps performed daily will be monitored using accelerometers

    Measured: Daily throughout the 11-day experimental period

  10. Change in physical activity-related energy expenditure

    Energy expenditure (kcal) related to habitual physical activity will be assessed using accelerometers

    Measured: Daily throughout the 11-day experimental period

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted8 Jul 2026
  2. Study start1 Sep 2026 (estimated)
  3. Primary completion20 Dec 2026 (estimated)
  4. Study completion20 Jan 2027 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Other
Allocation
Randomised
Intervention model
Crossover
Masking
Triple blind
Who is masked
Participant, Investigator, Outcomes assessor
Enrolment
20 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07690124
Sponsor's protocol ID
UTH-06/13.02.2026
Status last verified
May 2026
First submitted
9 Jun 2026
Last updated
8 Jul 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

A study testing 200 mg S-Acetyl Glutathione and 500 mg S-Acetyl Glutathione in people with Performance Recovery and Exercise-induced Inflammation, run by University of Thessaly at 1 site in Greece.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 5 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: opening soon, as of the sponsor's last update on 8 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Greece. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Dimitrios Draganidis, PhD (+30 2431047078, ddraganidis@uth.gr), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Change in creatine kinase levels (time frame: Day 1, day 7, day 9, day 10 and day 11). The study lists 13 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 8 Jul 2026.

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