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Completed

NCT Number: NCT07754669

Priming Using Contrast Training Exercise

This study investigated the effects of a morning complex-contrast training session on afternoon sport-specific and physical performance in competitive judokas. The study focused on identifying whether a stimulus targeting both force and velocity components of the force-velocity curve could induce a "delayed potentiation" effect 6 hours later and whether these responses differed by sex.

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Key information

Conditions

Athletic Performance

Age range

18 year–22 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Academy of Physical Education in Katowice

Katowice, Silesian Voivodeship, 40-065, Poland

About this study

A randomized, counterbalanced crossover design was utilized to evaluate the efficacy of a morning priming protocol (using complex-contrast training exercises) compared to a control condition. Competitive male and female judo athletes performed a low-volume, high-intensity priming session consisting of heavy resistance and ballistic exercises in a set-by-set fashion. Physical performance was assessed using the Special Judo Fitness Test, handgrip strength, and countermovement jump height. Results were analyzed to determine the fatigue-potentiation balance over a 6-hour recovery window and to examine sex-based interactions in the priming response.

Who can participate

Healthy volunteers accepted: Yes

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

Inclusion criteria

  • age between 18 and 22 years;
  • competitive male or female judo athlete;
  • minimum of 3 years of experience in structured judo training;
  • previous experience with and technical proficiency in resistance and ballistic training exercises;
  • ability to correctly perform the back squat, bench press, countermovement jump, and wall ball slam;
  • technical proficiency in performing the Ippon Seoi-Nage throwing technique; previous experience with the Special Judo Fitness Test;
  • absence of musculoskeletal injuries or medical conditions that would restrict participation in maximal physical exercise;
  • ability to complete both experimental conditions and all required performance assessments;
  • provision of written informed consent before participation.

Exclusion criteria

  • less than 3 years of structured judo training experience;
  • insufficient technical proficiency in the back squat, bench press, countermovement jump, or wall ball slam;
  • inability to correctly perform the Ippon Seoi-Nage technique;
  • no previous experience with the Special Judo Fitness Test;
  • current musculoskeletal pain or injury that could affect resistance exercise, jumping, handgrip assessment, or judo-specific performance;
  • presence of a medical condition that could restrict maximal physical effort or - make participation in the intervention unsafe;
  • inability to complete either experimental condition or the required testing procedures

Treatment and study plan

Morning Complex-Contrast Training

Behavioral

At approximately 9:00 AM, participants completed a standardized warm-up consisting of a 10-minute self-paced jog followed by dynamic stretching. Baseline countermovement jump and maximum isometric handgrip strength measurements were subsequently performed.

The CCT intervention consisted of:

3 lower-body contrast sets, with 6 repetitions of the back squat paired with 6 maximal countermovement jumps; 3 upper-body contrast sets, with 6 repetitions of the bench press paired with 6 maximal wall ball slams.

After completing the morning session, participants underwent a 6-hour passive recovery period. At approximately 3:00 PM, they repeated the standardized warm-up and completed the countermovement jump, maximum isometric handgrip strength, and Special Judo Fitness Test assessments.

Time-Matched Walking Control Condition

Behavioral

At approximately 9:00 AM, participants completed a standardized warm-up consisting of a 10-minute self-paced jog followed by dynamic stretching. Baseline countermovement jump and maximum isometric handgrip strength measurements were then performed.

Following the baseline measurements, participants walked for the duration required to complete the CCT protocol in the experimental condition. After the 6-hour recovery interval, participants returned at approximately 3:00 PM, repeated the standardized warm-up, and completed the countermovement jump, maximum isometric handgrip strength, and Special Judo Fitness Test assessments.

Primary outcomes

  1. Special Judo Fitness Test Index

    Time frame: Approximately 6 hours post-intervention

    Judo-specific performance efficiency assessed using the Special Judo Fitness Test (SJFT). The test consisted of three work periods: one 15-second period followed by two 30-second periods, separated by 10-second recovery intervals.

    During each period, the participant moved between two partners positioned 3 meters apart and performed the Ippon Seoi-Nage throwing technique as many times as possible. Heart rate was measured immediately after the test and 1 minute after test completion using a chest strap-based heart rate monitor.

    The SJFT index was calculated using the total number of completed throws and the heart rate values recorded immediately and 1 minute after the test. A lower SJFT index represents better judo-specific performance efficiency.

Secondary outcomes

  1. Total Number of Throws During the Special Judo Fitness Test

    Time frame: Approximately 6 hours post-intervention

    The total number of successfully completed Ippon Seoi-Nage throws during all three periods of the Special Judo Fitness Test. The result was calculated as the sum of throws completed during the 15-second period and the two 30-second periods. A higher number of throws indicates better judo-specific performance.

  2. Number of Throws During Individual Special Judo Fitness Test Periods

    Time frame: Approximately 6 hours post-intervention

    The number of successfully completed Ippon Seoi-Nage throws was recorded separately during each of the three SJFT periods:

    Set 1: 15 seconds; Set 2: 30 seconds; Set 3: 30 seconds.

    The work periods were separated by 10-second recovery intervals. Results were reported as the number of completed throws in each set.

  3. Left-Hand Maximum Isometric Handgrip Strength

    Time frame: Baseline and approximately 6 hours post-intervention

    Maximum isometric handgrip strength of the left hand measured using a handheld Jamar dynamometer (Lafayette, California, USA).

    Participants were seated upright with their feet flat on the floor, the upper arm positioned close to the torso, the elbow flexed to 90°, and the wrist maintained in a neutral position. During each trial, participants exerted maximal force against the dynamometer for 5 seconds. Attempts were alternated between the left and right hands, with a 1-minute recovery interval between trials.

    Handgrip strength was reported in kilograms (kg).

  4. Right-Hand Maximum Isometric Handgrip Strength

    Time frame: Baseline and approximately 6 hours post-intervention

    Maximum isometric handgrip strength of the right hand measured using a handheld Jamar dynamometer (Lafayette, California, USA).

    Participants were seated upright with their feet flat on the floor, the upper arm positioned close to the torso, the elbow flexed to 90°, and the wrist maintained in a neutral position. During each trial, participants exerted maximal force against the dynamometer for 5 seconds. Attempts were alternated between the left and right hands, with a 1-minute recovery interval between trials.

    Handgrip strength was reported in kilograms (kg).

  5. Countermovement Jump Height

    Time frame: Baseline and approximately 6 hours post-intervention

    Vertical jump height measured during a countermovement jump using a portable force platform sampling at 2000 Hz.

    Participants performed three maximal-effort countermovement jumps with their hands positioned on their hips and were allowed to use a self-selected countermovement depth. A 1-minute recovery interval was provided between trials. Jump height was reported in centimeters (cm).

  6. Heart Rate Immediately After the Special Judo Fitness Test

    Time frame: Immediately after the Special Judo Fitness Test performed approximately 6 hours post-intervention

    Heart rate measured immediately following completion of the Special Judo Fitness Test using a chest strap-based heart rate monitor. Heart rate was reported in beats per minute (bpm).

  7. Heart Rate One Minute After the Special Judo Fitness Test

    Time frame: One minute after the Special Judo Fitness Test performed approximately 6 hours post-intervention

    Heart rate measured 1 minute following completion of the Special Judo Fitness Test using a chest strap-based heart rate monitor. Heart rate was reported in beats per minute (bpm).

Sponsors and collaborators

Lead sponsor

The Jerzy Kukuczka Academy of Physical Education in Katowice

Other

Registry information

Official study title

Effects of Morning Contrast Training Exercise on the Afternoon Priming of Judoka's Athletic and Sport-specific Performance

Important dates

Study start
2026
Primary completion
2026
Study completion
2026
First posted
Aug 10, 2026
Registry last updated
Aug 10, 2026

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

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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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