Contrast Training and Volleyball Players' Jumping Ability

NCT07799701 | Completed

• 1 other identifier: AWFiS/2026_3_WG
• Study Type: interventional
• Target: 42
• Locations: 1 country
• Sites: 1

Brief Summary

The aim of the study was to compare the effects of three 10-week training interventions on vertical jump performance in volleyball players. Jump performance was assessed using the countermovement jump with arm swing (CMJ+AS) and drop jumps from heights of 20 cm (DJ20) and 60 cm (DJ60). Forty-two male volleyball athletes were recruited, of whom 38 completed the intervention protocol. Participants were assigned to one of three training groups: (i) contrast training with elastic-band assistance (G-CNT), (ii) traditional contrast training (CNT), or (iii) complex training (CTRL). The interventions lasted 10 weeks and included two training sessions per week. Pre- and post-intervention testing was performed using a Kistler 9286BA force platform. During CMJ+AS, jump height (JH), relative peak power (RPP), countermovement time (CMT), and modified reactive strength index (RSImod) were assessed. During DJ20 and DJ60, jump height (JH), relative peak power (RPP), ground contact time (CT), and reactive strength index (RSI) were assessed. Based on the smallest worthwhile change (SWC) in the tested variables, participants were categorized as positive responders, non-responders, or negative responders.

Conditions

Physical Performance

Keywords

Contrast training; Assisted plyometric training; Plyometric training; Elastic bands; Volleyball performance; Volleyball; Neuromuscular performance

Outcome Measures

Primary Outcomes (2)

• Relative Peak Power (RPP)

  Relative peak power (RPP, W/kg) was assessed during the countermovement jump with arm swing (CMJ+AS) and drop jumps from 20-cm (DJ20) and 60-cm (DJ60) heights using a Kistler 9286BA force platform. RPP was expressed relative to body mass. Participants performed repeated trials of each jump test, and data from the trial with the greatest jump height were retained for analysis.

  3-5 days before the start of the intervention and 3-5 days after completion of the 10-week intervention.

• Jump Height

  Jump height (JH, cm) was assessed during the countermovement jump with arm swing (CMJ+AS) and drop jumps from 20-cm (DJ20) and 60-cm (DJ60) heights using a Kistler 9286BA force platform. Participants performed two trials of each jump test, and the trial with the greatest jump height was retained for analysis.

  3-5 days before the start of the intervention and 3-5 days after completion of the 10-week intervention.

Secondary Outcomes (4)

• Countermovement Time

  3-5 days before the start of the intervention and 3-5 days after completion of the 10-week intervention.

• Reactive Strength Index

  3-5 days before the start of the intervention and 3-5 days after completion of the 10-week intervention.

• Modified Reactive Strength Index

  3-5 days before the start of the intervention and 3-5 days after completion of the 10-week intervention.

• Contact Time

  3-5 days before the start of the intervention and 3-5 days after completion of the 10-week intervention.

Study Arms (3)

Elastic Band-Assisted Contrast Training (G-CNT)

EXPERIMENTAL

Participants performed a 10-week contrast training program twice per week. High-intensity resistance exercises (conditioning activities) were paired with biomechanically similar high-velocity exercises (post-conditioning activities). Selected plyometric exercises were performed with elastic-band assistance to partially reduce body mass load and enable higher movement velocities.

Behavioral: Elastic Band-Assisted Contrast Training (G_CNT)

Contrast Training (CNT)

EXPERIMENTAL

Participants performed a 10-week traditional contrast training program twice per week. High-intensity resistance exercises (conditioning activities) were paired with biomechanically similar high-velocity exercises (post-conditioning activities). The plyometric exercises were performed without elastic-band assistance.

Behavioral: Contrast Training (CNT)

Complex Training (CTRL)

ACTIVE COMPARATOR

Participants performed a 10-week complex training program twice per week. The program included both high-intensity resistance exercises and high-velocity exercises; however, these exercises were not alternated in contrast pairs. Resistance exercises were performed first, followed by high-velocity exercises later in the same training session.

Behavioral: Complex Training (CTRL)

Interventions

Contrast Training (CNT) BEHAVIORAL

Participants completed a 10-week traditional contrast training program with two weekly sessions (Tuesday and Thursday), divided into three progressive phases (weeks 1-4, 5-7, and 8-10). High-intensity resistance exercises were paired with biomechanically similar high-velocity exercises. Tuesday included back squat-vertical jumps, lat pulldown-medicine ball throws, and barbell hip thrust-broad jumps. Thursday included power cleans, split squats-split-stance vertical jumps, bench press-medicine ball chest throws, and hex-bar deadlift-drop jumps. Resistance intensity was individualized based on 1RM and progressively increased (approximately 60-92.5% 1RM), while repetitions decreased. Depending on the exercise and phase, 3-5 sets were performed. High-velocity exercises generally included 5-6 repetitions. Unlike G-CNT, all jumping exercises were performed without elastic-band assistance. Rest intervals were 60 s after resistance and 120 s after high-velocity exercises.

Also known as: CNT

Contrast Training (CNT)

Complex Training (CTRL) BEHAVIORAL

Participants completed a 10-week complex training program with two weekly sessions (Tuesday and Thursday), divided into three progressive phases (weeks 1-4, 5-7, and 8-10). Unlike the G-CNT and CNT groups, resistance and high-velocity exercises were not alternated in contrast pairs. Resistance exercises were performed first, followed by high-velocity exercises. The program included back squats, hip thrusts, lat pulldowns, power cleans, split squats, hex-bar deadlifts, and bench press, followed by vertical jumps, broad jumps, drop jumps, split-stance vertical jumps, and medicine ball throws. Resistance intensity was individualized based on 1RM and progressively increased (approximately 60-92.5% 1RM), while repetitions decreased. Depending on the exercise and phase, 3-5 sets were performed. High-velocity exercises included 5-6 repetitions. Rest intervals ranged from 60-180 s after resistance exercises and were 120 s after high-velocity exercises.

Complex Training (CTRL)

Elastic Band-Assisted Contrast Training (G_CNT) BEHAVIORAL

Participants completed a 10-week contrast training program with two weekly sessions (Tuesday and Thursday), divided into three progressive phases (weeks 1-4, 5-7, and 8-10). High-intensity resistance exercises were paired with biomechanically similar high-velocity exercises. Tuesday included back squat-vertical jumps, lat pulldown-medicine ball throws, and barbell hip thrust-broad jumps. Thursday included power cleans, split squats-split-stance vertical jumps, bench press-medicine ball chest throws, and hex-bar deadlift-drop jumps. Resistance intensity was individualized based on 1RM and progressively increased (approximately 60-92.5% 1RM), while repetitions decreased. Depending on the exercise and phase, 3-5 sets were performed. High-velocity exercises generally included 5-6 repetitions. In G-CNT, selected vertical jumps were performed with elastic-band assistance. Rest intervals were 60 s after resistance and 120 s after high-velocity exercises.

Also known as: G-CNT

Elastic Band-Assisted Contrast Training (G-CNT)

Eligibility Criteria

• Age: 17 Years - 22 Years
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Child (0-17), Adult (18-64)

You may qualify if:

• Male volleyball players.
• Age between 17 and 22 years.
• At least 12 months of regular high-intensity resistance training experience.
• At least 12 months of technical volleyball training experience.

You may not qualify if:

• Injury sustained within the 3 months preceding enrollment that could affect participation in training or testing.
• Training absence exceeding 4 consecutive weeks during the previous 12 months.

Sponsors & Collaborators

• Gdansk University of Physical Education and Sport: lead

Study Sites (1)

Gdansk University of Physical Education and Sport

Gdansk, 80-336, Poland

Location

Related Publications (2)

• Sheppard JM, Dingley AA, Janssen I, Spratford W, Chapman DW, Newton RU. The effect of assisted jumping on vertical jump height in high-performance volleyball players. J Sci Med Sport. 2011 Jan;14(1):85-9. doi: 10.1016/j.jsams.2010.07.006. Epub 2010 Sep 9.

  PMID: 20829109 BACKGROUND

• Argus CK, Gill ND, Keogh JW, Blazevich AJ, Hopkins WG. Kinetic and training comparisons between assisted, resisted, and free countermovement jumps. J Strength Cond Res. 2011 Aug;25(8):2219-27. doi: 10.1519/JSC.0b013e3181f6b0f4.

  PMID: 21654341 BACKGROUND

MeSH Terms

Interventions

Chymases

Intervention Hierarchy (Ancestors)

Serine Endopeptidases; Endopeptidases; Peptide Hydrolases; Hydrolases; Enzymes; Enzymes and Coenzymes; Serine Proteases

Study Officials

• Wojciech Grzyb, MSc

  Gdansk University of Physical Education and Sport

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Masking Details: Due to the nature of the exercise interventions, blinding of participants and coaches was not feasible. Participants and coaches were not informed of the study hypotheses. Statistical analysis was performed by a statistician who was blinded to group allocation.
• Purpose: OTHER
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: MSc

Model Details: A three-arm parallel-group study with cluster randomization at the team level. Three volleyball teams were randomly assigned to one of three 10-week training interventions: elastic band-assisted contrast training (G-CNT), traditional contrast training (CNT), or complex training (CTRL). Each team followed its assigned intervention throughout the study, with no crossover between groups.

Study Record Dates

• First Submitted: August 20, 2026
• First Posted: September 2, 2026
• Study Start: April 4, 2023
• Primary Completion: June 6, 2023
• Study Completion: June 6, 2023
• Last Updated: September 2, 2026

Record last verified: 2026-08

Data Sharing

• IPD Sharing: Will not share

Locations

PL (1)