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NCT Number: NCT07714057

Effect of Hydrogen-rich Water During Tapering on Recovery After Functional Overreaching in Basketball Players

The goal of this clinical trial is to evaluate whether hydrogen-rich water supplementation during tapering improves recovery after functional overreaching in competitive male basketball players aged 18-35 years. The main questions it aims to answer are:

* Does hydrogen-rich water improve autonomic recovery after functional overreaching? * Does hydrogen-rich water improve recovery in biochemical, performance, and subjective feeling outcomes during tapering?

Researchers will compare hydrogen-rich water to placebo (water containing no molecular hydrogen) to determine whether molecular hydrogen improves recovery after accumulated fatigue has been induced by functional overreaching. Participants will:

* Complete a training cycle including normal training, functional overreaching, and tapering. * Consume hydrogen-rich or placebo water daily during the one-week tapering period. * Undergo repeated testing of autonomic nervous system, blood biochemical markers, performance, and subjective soreness.

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Key information

Age range

18 year–35 year

Sex eligibility

Male

Study type

Interventional

Phase

Not applicable

Primary location

Palacky University, Faculty of Physical Culture

Olomouc, 77111, Czechia

Location status: Recruiting

Location contact

About this study

The study consists of an initial screening and entry testing phase, followed by one week of normal training, two weeks of functional overreaching, and one week of tapering. During the functional overreaching period, training load is increased to approximately 120-130% of normal training load to induce accumulated fatigue. During the tapering period, training volume is reduced to approximately 50-60% of normal training volume to support recovery and performance rebound.

The molecular hydrogen is administered only during the tapering period. Participants in the experimental group consume 2.5 L per day of hydrogen-rich water. The total daily dose is divided into 0.5 L in the morning, 1.5 L around training, and 0.5 L in the evening. Participants in the placebo group consume visually matched placebo water according to the same total daily intake and timing schedule. Supplementation adherence is monitored using logs, dose counts, and attendance records. Participants are randomly assigned in a 1:1 ratio to either the experimental group or the placebo group. Randomization is performed using a block scheme and a computer random number generator.

Testing is performed at multiple time points: entry laboratory testing, baseline after normal training, post-functional overreaching, and post-taper. The primary interval for evaluation is the change from post-functional overreaching to post-taper. Statistical analysis is based on a t-test or analysis of variance. Data that not follow a normal distribution are treated using a logarithmic transformation or analyzed using nonparametric tests. The significance level is set at 0.05.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Competitive male basketball players.
  • Signed informed consent.
  • Completion of entry medical and laboratory screening.

Exclusion criteria

  • Acute injury or infection.
  • History or presence of relevant cardiovascular, respiratory, metabolic, or other disease that may affect the study results.
  • Use of medication affecting recovery markers or study results.

Treatment and study plan

Hydrogen-rich water

Dietary Supplement

Hydrogen-rich water with molecular hydrogen concentration >1.0 ppm.

Other names: Tirtan generator (Nutristamina, Ostrava, Czech Republic)

Placebo Water

Dietary Supplement

Tap water without molecular hydrogen.

Primary outcomes

  1. RMSSD

    Time frame: One-week change between post-overreaching and post-taper.

    The root mean square of successive differences of RR intervals (RMSSD) is used as an index of parasympathetic activity and is calculated from an ECG using heart rate variability analysis.

Secondary outcomes

  1. Creatine kinase

    Time frame: One-week change between post-overreaching and post-taper.

    Blood creatine kinase concentration is used as a marker of muscle damage.

  2. High-sensitivity C-reactive protein

    Time frame: One-week change between post-overreaching and post-taper.

    High-sensitivity C-reactive protein concentration is used as a marker of systemic inflammatory.

  3. Cortisol

    Time frame: One-week change between post-overreaching and post-taper.

    Blood cortisol concentration is used as a marker of physiological stress response.

  4. Testosterone

    Time frame: One-week change between post-overreaching and post-taper.

    Blood testosterone concentration is used as a marker related to anabolic-catabolic balance.

  5. Urea

    Time frame: One-week change between post-overreaching and post-taper.

    Blood urea concentration is used as a marker related to metabolic and protein-turnover stress.

  6. Leukocytes

    Time frame: One-week change between post-overreaching and post-taper.

    Blood leukocyte count is used as a marker of immune-related response to training.

  7. Lymphocytes

    Time frame: One-week change between post-overreaching and post-taper.

    Blood lymphocyte count is used as a marker of immune-related response to training.

  8. Neutrophils

    Time frame: One-week change between post-overreaching and post-taper.

    Blood lymphocyte count is used as a marker of imflammatory response to training.

  9. Reactive strength index

    Time frame: One-week change between post-overreaching and post-taper.

    Reactive strength index is used as an marker of neuromuscular function of the lower limbs and is measured using a drop jump.

  10. Hangrip test

    Time frame: One-week change between post-overreaching and post-taper.

    Handgrip test is used as a marker of forearm muscle strength and is measured using a dynamometer.

  11. 20-m sprint

    Time frame: One-week change between post-overreaching and post-taper.

    20-m sprint test is used to assess linear speed.

  12. Repeated sprint

    Time frame: One-week change between post-overreaching and post-taper.

    20 x 15 m repeated sprint test is used to asses repeated sprint ability.

  13. Agility T-test

    Time frame: One-week change between post-overreaching and post-taper.

    Agility T-test is used to assess planned change-of-direction performance.

  14. Basketball jump shot accuracy test

    Time frame: One-week change between post-overreaching and post-taper.

    Basketball jump shot accuracy test is used to assess basketball-specific performance.

  15. Muscle soreness

    Time frame: One-week change between post-overreaching and post-taper.

    Muscle soreness is assessed subjectively using a visual analog scale, which is represented by a 100 mm line marked 0 (no pain) and 100 (worst imaginable pain).

Study contacts

Contact information is provided by the study sponsor or research team.

Jakub Krejci, PhD

CONTACT

[email protected]

Jan Kvas

CONTACT

[email protected]

+420774678756

Sponsors and collaborators

Lead sponsor

Palacky University

Other

Registry information

Official study title

Effect of Hydrogen-rich Water Supplementation During Tapering on Recovery After Functional Overreaching in Competitive Male Basketball Players: A Randomized, Double-blind, Placebo-controlled Paralel-group Trial

Important dates

Study start
2026
Primary completion
2026
Study completion
2026
First posted
Jul 20, 2026
Registry last updated
Jul 28, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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