Priming Using Contrast Training Exercise

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.

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.

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.

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.

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).

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).

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).