An interventional study of Morning Complex-Contrast Training and Time-Matched Walking Control Condition in Athletic Performance, sponsored by The Jerzy Kukuczka Academy of Physical Education in Katowice. Completed at 1 site in Poland. Open to participants aged 18 Years to 22 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-08-10.
Sponsored by The Jerzy Kukuczka Academy of Physical Education in Katowice · Not applicable, Interventional, and Basic science
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.
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.
Exclusion Criteria:
Participants performed a morning complex-contrast training (CCT) session designed to induce a delayed priming effect on afternoon judo-specific and neuromuscular performance. The session consisted of lower- and upper-body contrast exercise pairs combining heavy resistance exercises with biomechanically related ballistic exercises. Following the intervention, participants completed a 6-hour passive recovery period before the afternoon performance assessment.
Behavioral: Morning Complex-Contrast Training
Participants completed the same standardized morning warm-up and baseline measurements as in the experimental condition. Following the baseline measurements, participants walked for a period corresponding to the duration of the complex-contrast training protocol. No resistance or ballistic exercises were performed. After the walking period, participants underwent a 6-hour recovery interval before completing the afternoon performance assessments.
Behavioral: Time-Matched Walking Control Condition
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.
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.
Special Judo Fitness Test Index
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.
Time frame: Approximately 6 hours post-intervention
Total Number of Throws During the Special Judo Fitness Test
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.
Time frame: Approximately 6 hours post-intervention
Number of Throws During Individual Special Judo Fitness Test Periods
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.
Time frame: Approximately 6 hours post-intervention
Left-Hand Maximum Isometric Handgrip Strength
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).
Time frame: Baseline and approximately 6 hours post-intervention
Right-Hand Maximum Isometric Handgrip Strength
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).
Time frame: Baseline and approximately 6 hours post-intervention
Countermovement Jump Height
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).
Time frame: Baseline and approximately 6 hours post-intervention
Heart Rate Immediately After the Special Judo Fitness Test
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).
Time frame: Immediately after the Special Judo Fitness Test performed approximately 6 hours post-intervention
Heart Rate One Minute After the Special Judo Fitness Test
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).
Time frame: One minute after the Special Judo Fitness Test performed approximately 6 hours post-intervention
Plan to share: Yes — De-identified individual participant data will be shared upon reasonable request after publication of the study results. Requests should be directed to the corresponding author.
Supporting information: Study protocol, Sap
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The Jerzy Kukuczka Academy of Physical Education in Katowice