Athletic PerformanceNCT07785778
Cluster Training in Female Volleyball Players
A study testing Traditional Resistance Training, Standard Cluster Resistance Training and Undulating Cluster Resistance Training in people with Athletic Performance and Volleyball Players, run by Birjand University of Medical Sciences at 1 site in Iran.
Trial summary
This study compares the effects of three different resistance training methods-traditional training, standard cluster training, and undulating cluster training-on strength, hormonal responses, and inflammation in female volleyball players aged 18-30 years. Read more about this study
- Who is it for?
- Ages 18 to 30 years, women onlyHealthy volunteers can take part
- Conditions the study is for
- Athletic Performance, Volleyball Players, Resistance Training
- What is being tested?
- Traditional Resistance Training, Standard Cluster Resistance Training and Undulating Cluster Resistance Training
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 30 participants
- Where
- 1 siteIran
- Study dates
- 20 Nov 2022to 30 Dec 2022
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 30 years
- Women only
- Healthy volunteers accepted
- Adult
Who may be able to join
- Female volleyball players aged 18 to 30 years
- At least 2 years of continuous training in volleyball and resistance training
- Complete health status (based on health and wellness questionnaire results)
- No anterior cruciate ligament injury or other upper-/lower-extremity injuries in the past 6 months
- Familiarity with basic resistance training techniques
- Non-pregnant, with regular menstrual cycles
- No regular use of medications (including oral contraceptives)
- No use of ergogenic supplements affecting muscle mass (e.g., anabolic steroids, growth hormone, or insulin-like substances) in the 6 months prior to the study
Who cannot join
- Absence from more than three consecutive training sessions
- Any musculoskeletal injury that prevented continuation of the training program
Trial locations and contacts
1 site in 1 country.
Iran1 site
Faculty of Sport Sciences, University of Birjand
Birjand, South Khorasan Province, 9717434765
About this study
Official title: Comparison of Traditional, Standard Cluster, and Undulating Cluster Resistance Training on Hormonal, Inflammatory, and Performance Outcomes in Female Volleyball Players: A Randomized Controlled Trial
This study compares the effects of three different resistance training methods-traditional training, standard cluster training, and undulating cluster training-on strength, hormonal responses, and inflammation in female volleyball players aged 18-30 years. Thirty participants with at least two years of volleyball and resistance training experience were randomly assigned to one of three groups. All participants performed resistance training three times per week and volleyball-specific training two times per week for eight weeks. Blood samples were taken before and after the first session (acute response) and after eight weeks (chronic adaptation) to measure testosterone, cortisol, IGF-1, progesterone, and C-reactive protein (CRP). Performance tests included upper-body and lower-body strength (bench press and squat), speed, agility, and vertical jump. The main finding was that undulating cluster training produced significantly greater improvements in upper-body strength compared to standard cluster training, while all three methods were equally effective for lower-body strength and other performance measures. No significant differences were found between groups for hormonal or inflammatory changes. The study provides practical guidance for coaches seeking to optimize upper-body strength gains in female volleyball players.
Read the detailed description
This study compares the effects of three different resistance training methods-traditional training, standard cluster training, and undulating cluster training-on strength, hormonal responses, and inflammation in female volleyball players aged 18-30 years. Thirty participants with at least two years of volleyball and resistance training experience were randomly assigned to one of three groups. All participants performed resistance training three times per week and volleyball-specific training two times per week for eight weeks. Blood samples were taken before and after the first session (acute response) and after eight weeks (chronic adaptation) to measure testosterone, cortisol, IGF-1, progesterone, and C-reactive protein (CRP). Performance tests included upper-body and lower-body strength (bench press and squat), speed, agility, and vertical jump. The main finding was that undulating cluster training produced significantly greater improvements in upper-body strength compared to standard cluster training, while all three methods were equally effective for lower-body strength and other performance measures. No significant differences were found between groups for hormonal or inflammatory changes. The study provides practical guidance for coaches seeking to optimize upper-body strength gains in female volleyball players.
- Being tested
- Traditional Resistance Training, Standard Cluster Resistance Training, Undulating Cluster Resistance Training
- Keywords
- Cluster, Configuration
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Traditional Resistance TrainingBehavioural
Eight weeks of traditional resistance training, 3 sessions per week. Each session includes 8 exercises: dumbbell thruster, power clean, back squat, deadlift, knee flexion curl, bench press, military p
Standard Cluster Resistance TrainingBehavioural
Eight weeks of standard cluster resistance training, 3 sessions per week. Same exercises and intensity progression as TRT, but with intra-set rest intervals (10-30 seconds between clusters) to maintain movement quality, repetition velocity, and power output across multiple sets.
Undulating Cluster Resistance TrainingBehavioural
Eight weeks of undulating cluster resistance training, 3 sessions per week. Combines intra-set rest intervals (10-30 seconds between clusters) with systematic weekly variations in load and repetition schemes. Intensity and volume undulate across weeks to balance neural drive and load tolerance while preserving high-quality repetitions.
| Study group | Role | What they receive |
|---|---|---|
| Traditional Resistance Training (TRT) | Active comparator | Eight weeks of traditional resistance training, 3 sessions per week. Linear progression with 240s inter-set rest (weeks 1-3), 200s (weeks 4-5), 180s (weeks 6-8). Exercises: dumbbell thruster, power clean, back squat, deadlift, knee flexion curl, bench press, military press, lat pulldown Receives: Behavioral: Traditional Resistance Training |
| Standard Cluster Resistance Training (SCRT) | Experimental | Eight weeks of standard cluster resistance training, 3 sessions per week. Similar to TRT but with intra-set rest intervals (10-30s between clusters) to maintain movement quality and power output. Receives: Behavioral: Standard Cluster Resistance Training |
| Undulating Cluster Resistance Training (UCRT) | Experimental | Eight weeks of undulating cluster resistance training, 3 sessions per week. Combines intra-set rest with systematic weekly variations in load and repetition schemes, balancing neural drive and load tolerance Receives: Behavioral: Undulating Cluster Resistance Training |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Relative Peak Power
Relative peak power derived from the CMJ height and body mass, calculated using the Sayers equation: Peak power (W) = 60.7 × jump height (cm) + 45.3 × body mass (kg) - 2055.
Measured: baseline and after 8- week
Secondary outcomes (10)
Change in Lower-Body Strength (Squat 1-RM)
Maximum dynamic strength of the lower body, measured using the estimated 1-repetition maximum (1-RM) test for the squat exercise. The 1-RM was estimated using the Brzycki formula based on the maximum weight participants could lift for 1-9 repetitions.
Measured: Baseline and 8 weeks
Change in Speed (20-m Sprint)
Sprint performance measured over a distance of 20 meters. Participants performed a maximal sprint, and the time was recorded in seconds.
Measured: baseline and after 8- week
Change in Agility
Agility performance measured using a standard agility test (e.g., T-test or similar). Participants performed the test, and the completion time was recorded in seconds.
Measured: baseline and after 8- week
Change in Countermovement Jump (CMJ) Height
Vertical jump height measured using a countermovement jump (CMJ) test. Participants performed 3 maximal jumps with 30-second rest intervals. The highest jump height (in centimeters) was recorded using a wall-mounted graduated tape. Peak power was then calculated using the Sayers equation.
Measured: baseline and after 8- week
Change in Relative Peak Power
Relative peak power derived from the CMJ height and body mass, calculated using the Sayers equation: Peak power (W) = 60.7 × jump height (cm) + 45.3 × body mass (kg) - 2055.
Measured: baseline and after 8- week
Change in Serum Testosterone
Serum levels of testosterone measured using commercial chemiluminescence immunoassay kits. Samples were collected before and after the first session (acute) and after eight weeks (chronic).
Measured: Baseline, immediately after the first session, and 48 hours after the last session (week 8)
Change in Serum Cortisol
Serum levels of cortisol measured using commercial chemiluminescence immunoassay kits. Samples were collected before and after the first session (acute) and after eight weeks (chronic).
Measured: Baseline, immediately after the first session, and 48 hours after the last session (week 8)
Change in Serum IGF-1
Serum levels of insulin-like growth factor-1 (IGF-1) measured using commercial chemiluminescence immunoassay kits. Samples were collected before and after the first session (acute) and after eight weeks (chronic).
Measured: Baseline, immediately after the first session, and 48 hours after the last session (week 8)
Change in Serum Progesterone
Serum levels of progesterone measured using commercial chemiluminescence immunoassay kits. Samples were collected before and after the first session (acute) and after eight weeks (chronic) to verify menstrual cycle phase.
Measured: Baseline, immediately after the first session, and 48 hours after the last session (week 8)
Change in Serum C-Reactive Protein (CRP)
Serum levels of C-reactive protein (CRP), an inflammatory marker, measured using an enhanced turbidimetric assay. Samples were collected before and after the first session (acute) and after eight weeks (chronic).
Measured: Baseline, immediately after the first session, and 48 hours after the last session (week 8)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Aug 2026
- Study start20 Nov 2022
- Primary completion20 Dec 2022
- Study completion30 Dec 2022
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Athletic PerformanceStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 30 participants (actual)
Sponsor and investigators
- Lead sponsor
- Birjand University of Medical Sciences
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Mohsen mohammadnia ahmadi, Birjand University of Medical Sciences
- Investigators
- Mohsen Mohammadnia Ahmadi, PhD, Principal investigator, university of birjand
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07785778
- Sponsor's protocol ID
- IR.BIRJAND.REC.1401.004
- Status last verified
- Aug 2026
- First submitted
- 17 Aug 2026
- Last updated
- 25 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 25 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Comparison of Traditional, Standard Cluster, and Undulating Cluster Resistance Training on Hormonal, Inflammatory, and Performance Outcomes in Female Volleyball Players: A Randomized Controlled Trial
- ClinicalTrials.gov ID
- NCT07785778
- Acronym / sponsor ID
- IR.BIRJAND.REC.1401.004
- Keywords
- Cluster, Configuration
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 30 participants (actual)
- Lead sponsor
- Birjand University of Medical SciencesUniversity, hospital or other
- Study start
- 20 Nov 2022 (actual)
- Primary completion
- 20 Dec 2022 (actual)
- Study completion
- 30 Dec 2022 (actual)
- First posted
- 25 Aug 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study compares the effects of three different resistance training methods-traditional training, standard cluster training, and undulating cluster training-on strength, hormonal responses, and inflammation in female volleyball players aged 18-30 years. Thirty participants with at least two years of volleyball and resistance training experience were randomly assigned to one of three groups. All participants performed resistance training three times per week and volleyball-specific training two times per week for eight weeks. Blood samples were taken before and after the first session (acute response) and after eight weeks (chronic adaptation) to measure testosterone, cortisol, IGF-1, progesterone, and C-reactive protein (CRP). Performance tests included upper-body and lower-body strength (bench press and squat), speed, agility, and vertical jump. The main finding was that undulating cluster training produced significantly greater improvements in upper-body strength compared to standard cluster training, while all three methods were equally effective for lower-body strength and other performance measures. No significant differences were found between groups for hormonal or inflammatory changes. The study provides practical guidance for coaches seeking to optimize upper-body strength gains in female volleyball players.
Detailed description
This study compares the effects of three different resistance training methods-traditional training, standard cluster training, and undulating cluster training-on strength, hormonal responses, and inflammation in female volleyball players aged 18-30 years. Thirty participants with at least two years of volleyball and resistance training experience were randomly assigned to one of three groups. All participants performed resistance training three times per week and volleyball-specific training two times per week for eight weeks. Blood samples were taken before and after the first session (acute response) and after eight weeks (chronic adaptation) to measure testosterone, cortisol, IGF-1, progesterone, and C-reactive protein (CRP). Performance tests included upper-body and lower-body strength (bench press and squat), speed, agility, and vertical jump. The main finding was that undulating cluster training produced significantly greater improvements in upper-body strength compared to standard cluster training, while all three methods were equally effective for lower-body strength and other performance measures. No significant differences were found between groups for hormonal or inflammatory changes. The study provides practical guidance for coaches seeking to optimize upper-body strength gains in female volleyball players.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Traditional Resistance Training (TRT) | Active comparator | Behavioral: Traditional Resistance TrainingEight weeks of traditional resistance training, 3 sessions per week. Linear progression with 240s inter-set rest (weeks 1-3), 200s (weeks 4-5), 180s (weeks 6-8). Exercises: dumbbell thruster, power clean, back squat, deadlift, knee flexion curl, bench press, military press, lat pulldown |
| Standard Cluster Resistance Training (SCRT) | Experimental | Behavioral: Standard Cluster Resistance TrainingEight weeks of standard cluster resistance training, 3 sessions per week. Similar to TRT but with intra-set rest intervals (10-30s between clusters) to maintain movement quality and power output. |
| Undulating Cluster Resistance Training (UCRT) | Experimental | Behavioral: Undulating Cluster Resistance TrainingEight weeks of undulating cluster resistance training, 3 sessions per week. Combines intra-set rest with systematic weekly variations in load and repetition schemes, balancing neural drive and load tolerance |
Who may qualify
- Ages
- 18 to 30 years
- Sex
- Female only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (8 listed)
- Female volleyball players aged 18 to 30 years
- At least 2 years of continuous training in volleyball and resistance training
- Complete health status (based on health and wellness questionnaire results)
- No anterior cruciate ligament injury or other upper-/lower-extremity injuries in the past 6 months
- Familiarity with basic resistance training techniques
Key exclusion criteria (2 listed)
- Absence from more than three consecutive training sessions
- Any musculoskeletal injury that prevented continuation of the training program
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Traditional Resistance TrainingEight weeks of traditional resistance training, 3 sessions per week. Each session includes 8 exercises: dumbbell thruster, power clean, back squat, deadlift, knee flexion curl, bench press, military p | Behavioural | Traditional Resistance Training (TRT) |
| Standard Cluster Resistance TrainingEight weeks of standard cluster resistance training, 3 sessions per week. Same exercises and intensity progression as TRT, but with intra-set rest intervals (10-30 seconds between clusters) to maintain movement quality, repetition velocity, and power output across multiple sets. | Behavioural | Standard Cluster Resistance Training (SCRT) |
| Undulating Cluster Resistance TrainingEight weeks of undulating cluster resistance training, 3 sessions per week. Combines intra-set rest intervals (10-30 seconds between clusters) with systematic weekly variations in load and repetition schemes. Intensity and volume undulate across weeks to balance neural drive and load tolerance while preserving high-quality repetitions. | Behavioural | Undulating Cluster Resistance Training (UCRT) |
Primary outcome
Change in Relative Peak Power
Time frame: baseline and after 8- week
Relative peak power derived from the CMJ height and body mass, calculated using the Sayers equation: Peak power (W) = 60.7 × jump height (cm) + 45.3 × body mass (kg) - 2055.
10 secondary outcomes
Change in Lower-Body Strength (Squat 1-RM)
Time frame: Baseline and 8 weeks
Change in Speed (20-m Sprint)
Time frame: baseline and after 8- week
Change in Agility
Time frame: baseline and after 8- week
Change in Countermovement Jump (CMJ) Height
Time frame: baseline and after 8- week
Change in Relative Peak Power
Time frame: baseline and after 8- week
Change in Serum Testosterone
Time frame: Baseline, immediately after the first session, and 48 hours after the last session (week 8)
Change in Serum Cortisol
Time frame: Baseline, immediately after the first session, and 48 hours after the last session (week 8)
Change in Serum IGF-1
Time frame: Baseline, immediately after the first session, and 48 hours after the last session (week 8)
Change in Serum Progesterone
Time frame: Baseline, immediately after the first session, and 48 hours after the last session (week 8)
Change in Serum C-Reactive Protein (CRP)
Time frame: Baseline, immediately after the first session, and 48 hours after the last session (week 8)
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 25 Aug 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Mohsen Mohammadnia Ahmadi, PhD principal investigator
university of birjand
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Traditional Resistance Training, Standard Cluster Resistance Training and Undulating Cluster Resistance Training in people with Athletic Performance and Volleyball Players, run by Birjand University of Medical Sciences at 1 site in Iran.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 8 inclusion and 2 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 25 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Iran. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in Relative Peak Power (time frame: baseline and after 8- week). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 25 Aug 2026.