Variable ResistanceNCT07846774
Acute Effects of Variable-Resistance and Free-Weight Bench Pull Exercise in Resistance-Trained Men
A study testing High-Load Variable-Resistance Bench Pull and High-Load Free-Weight Bench Pull in people with Variable Resistance and Free Weight, run by South China Normal University at 1 site in China.
Trial summary
This study used a randomized, counterbalanced crossover design to compare high-load chain-based variable-resistance (VR) and free-weight (FW) bench pulls. Resistance-trained men completed two experimental sessions separated by 72 hours, with the order of the VR and FW conditions randomized. Read more about this study
- Who is it for?
- Ages 18 to 30 years, men onlyHealthy volunteers can take part
- Conditions the study is for
- Variable Resistance, Free Weight
- What is being tested?
- High-Load Variable-Resistance Bench Pull and High-Load Free-Weight Bench Pull
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 15 participants
- Where
- 1 siteChina
- Study dates
- 15 Apr 2026to 1 Sep 2026
- 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
- Men only
- Healthy volunteers accepted
- Adult
Who may be able to join
- Male adults aged 18-30 years.
- At least 1 year of resistance-training experience.
- Proficiency in the bench-pull technique.
- Bench-pull one-repetition maximum (1RM) of at least 1.0 × body mass.
- No current use of medications that could affect neuromuscular performance.
- No history of cardiovascular, neurological, or metabolic disease.
- No upper-body musculoskeletal injury within the previous year.
- Willing and able to provide written informed consent.
Who cannot join
- Consumption of caffeine within 12 hours before testing.
- Consumption of alcohol within 24 hours before testing.
- Performance of any upper-body pulling exercise within 48 hours before testing.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Acute Comparison of High-Load Variable-Resistance and Free-Weight Bench Pulls: A Randomized Crossover Study of Exercise Responses and Residual Effects
This study used a randomized, counterbalanced crossover design to compare high-load chain-based variable-resistance (VR) and free-weight (FW) bench pulls. Resistance-trained men completed two experimental sessions separated by 72 hours, with the order of the VR and FW conditions randomized.
Before each experimental condition, participants completed a standardized general and bench pull-specific warm-up followed by a 10-minute rest period. In each session, participants performed one set of three bench pull repetitions at approximately 85% of their free-weight one-repetition maximum (1RM). In the VR condition, the external resistance was provided by a combination of barbell load and chains, with chains contributing approximately 20% of the effective mean total load. In the FW condition, the external resistance was provided entirely by the barbell.
Read more
Following the high-load bench pull, participants rested for 3 minutes and then completed three standardized sets of free-weight bench pulls at approximately 75% 1RM, with 3-minute rest intervals between sets. Each subsequent set was terminated when the mean velocity of a repetition fell below 0.65 m·s-¹ or when the participant was unable to complete the prescribed range of motion.
Direct exercise responses during the high-load bench pulls were assessed using movement velocity and surface electromyography. Residual effects during the subsequent free-weight sets were assessed using repetition count, movement velocity, and surface electromyography. The crossover design allowed each participant to complete both loading conditions and therefore serve as his own control.
Read the detailed description
This study used a randomized, counterbalanced crossover design to compare the acute effects of high-load chain-based variable resistance (VR) and free-weight (FW) resistance during the bench pull exercise. Resistance-trained men completed both experimental conditions in separate sessions, with the order of conditions randomized and the sessions separated by 72 hours.
Before each experimental condition, participants completed a standardized general warm-up and a bench pull-specific warm-up, followed by a 10-minute rest period. In each session, participants performed one set of three bench pull repetitions at approximately 85% of their free-weight one-repetition maximum (1RM). In the VR condition, external resistance was provided by a combination of barbell load and chains, with chains contributing approximately 20% of the effective mean total load. In the FW condition, external resistance was provided entirely by the barbell.
After the high-load bench pull, participants rested for 3 minutes and then completed three standardized sets of free-weight bench pulls at approximately 75% 1RM, with 3-minute rest intervals between sets. Each subsequent set was terminated when the mean velocity of a repetition fell below 0.65 m·s-¹ or when the participant was unable to complete the prescribed range of motion.
Movement velocity and surface electromyography were recorded during the high-load bench pulls to evaluate direct exercise responses. During the subsequent free-weight sets, repetition count, movement velocity, and surface electromyography were assessed to evaluate residual effects of the preceding high-load condition. The crossover design allowed each participant to complete both loading conditions and therefore serve as his own control.
- Conditions
- Variable Resistance, Free Weight
- Being tested
- High-Load Variable-Resistance Bench Pull, High-Load Free-Weight Bench Pull
- Keywords
- Variable Resistance Training, Chain Resistance, Bench Pull
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
High-Load Variable-Resistance Bench PullOther
Participants performed one set of three bench-pull repetitions at approximately 85% of their free-weight one-repetition maximum. External resistance was provided by a combination of barbell load and chains, with the chains contributing approximately 20% of the effective mean total load. Participants were instructed to perform the concentric phase with maximal intended velocity. After the high-load bench pull, participants rested for 3 minutes and then completed three standardized free-weight bench-pull sets at approximately 75% of one-repetition maximum, with 3-minute rest intervals between sets. Each subsequent set was terminated when mean repetition velocity fell below 0.65 m·s-¹ or when the prescribed range of motion could not be completed.
High-Load Free-Weight Bench PullOther
Participants performed one set of three bench-pull repetitions at approximately 85% of their free-weight one-repetition maximum, with the external resistance provided entirely by the barbell. Participants were instructed to perform the concentric phase with maximal intended velocity. After the high-load bench pull, participants rested for 3 minutes and then completed three standardized free-weight bench-pull sets at approximately 75% of one-repetition maximum, with 3-minute rest intervals between sets. Each subsequent set was terminated when mean repetition velocity fell below 0.65 m·s-¹ or when the prescribed range of motion could not be completed.
| Study group | Role | What they receive |
|---|---|---|
| Variable Resistance, Then Free Weight | Experimental | Participants completed the high-load variable-resistance bench-pull condition during the first experimental session and the high-load free-weight bench-pull condition during the second experimental session. The two sessions were separated by 72 hours. In each session, the high-load bench pull was followed after 3 minutes by three standardized free-weight bench-pull sets at approximately 75% of one-repetition maximum. Receives: Other: High-Load Variable-Resistance Bench Pull; Other: High-Load Free-Weight Bench Pull |
| Free Weight, Then Variable Resistance | Experimental | Participants completed the high-load free-weight bench-pull condition during the first experimental session and the high-load variable-resistance bench-pull condition during the second experimental session. The two sessions were separated by 72 hours. In each session, the high-load bench pull was followed after 3 minutes by three standardized free-weight bench-pull sets at approximately 75% of one-repetition maximum. Receives: Other: High-Load Variable-Resistance Bench Pull; Other: High-Load Free-Weight Bench Pull |
What is being measured
The primary outcome is the main question the study is designed to answer.
Average Mean and Peak Velocity During the High-Load Bench Pull
Movement velocity was measured using a linear position transducer sampling at 100 Hz. Mean velocity and peak velocity were obtained for each of the three repetitions performed during the high-load bench-pull set. For each loading condition, average mean velocity and average peak velocity were calculated by averaging the corresponding values across the three repetitions. Velocity was expressed in meters per second (m·s-¹).
Measured: Day 1 and Day 4, during the high-load bench-pull set
Normalized Surface Electromyography Amplitude During the High-Load Bench Pull
Surface electromyography was recorded from the right latissimus dorsi, teres major, posterior deltoid, and middle trapezius. Root mean square amplitudes were normalized to the maximal root mean square amplitude obtained during maximal voluntary isometric contraction testing and expressed as a percentage of maximal voluntary isometric contraction (%MVIC). Mean and peak electromyography amplitudes were obtained for each repetition and averaged separately across the three high-load repetitions.
Measured: Day 1 and Day 4, during the high-load bench-pull set
Number of Valid Repetitions Completed During Subsequent Free-Weight Bench-Pull Sets
Participants completed three subsequent free-weight bench-pull sets at approximately 75% of one-repetition maximum. Each set was terminated when the mean velocity of a repetition fell below 0.65 m·s-¹ or when the participant was unable to complete the prescribed range of motion. The number of valid repetitions completed in each of the three sets was recorded.
Measured: Day 1 and Day 4, beginning 3 minutes after the high-load bench-pull set
Movement Velocity During Subsequent Free-Weight Bench-Pull Sets
Mean and peak velocity were measured during each of the three subsequent free-weight bench-pull sets. For the repetition-matched analysis, velocity outcomes included average velocity, fastest-repetition velocity, matched-final velocity, velocity maintenance, and velocity decline. Repetition matching was performed separately for each participant and corresponding set using the smaller number of valid repetitions completed across the two experimental conditions.
Measured: Day 1 and Day 4, beginning 3 minutes after the high-load bench-pull set
Normalized Surface Electromyography Amplitude During Subsequent Free-Weight Bench-Pull Sets
Mean and peak surface electromyography amplitudes were assessed for the right latissimus dorsi, teres major, posterior deltoid, and middle trapezius during each of the three subsequent free-weight bench-pull sets. Electromyography amplitudes were normalized to maximal voluntary isometric contraction and expressed as %MVIC. For the repetition-matched analysis, mean and peak amplitudes were averaged separately across all included repetitions within each set.
Measured: Day 1 and Day 4, beginning 3 minutes after the high-load bench-pull set
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 Sep 2026
- Study start15 Apr 2026
- Primary completion30 Jun 2026
- Study completion1 Sep 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Variable ResistanceStudies 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
- Crossover
- Model description
- Participants completed both high-load variable-resistance and free-weight bench-pull conditions in a randomized, counterbalanced order. The two experimental sessions were separated by 72 hours. Participants assigned to one sequence completed the variable-resistance condition first followed by the free-weight condition, whereas participants assigned to the other sequence completed the conditions in the reverse order.
- Masking
- None (open label)
- Enrolment
- 15 participants (actual)
Sponsor and investigators
- Lead sponsor
- South China Normal University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Zongwei Chen, South China Normal University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07846774
- Sponsor's protocol ID
- TJUS 2025-117
- Status last verified
- Sep 2026
- First submitted
- 17 Sep 2026
- Last updated
- 29 Sep 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 29 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Acute Comparison of High-Load Variable-Resistance and Free-Weight Bench Pulls: A Randomized Crossover Study of Exercise Responses and Residual Effects
- ClinicalTrials.gov ID
- NCT07846774
- Acronym / sponsor ID
- TJUS 2025-117
- Conditions
- Variable Resistance, Free Weight
- Keywords
- Variable Resistance Training, Chain Resistance, Bench Pull
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 15 participants (actual)
- Lead sponsor
- South China Normal UniversityUniversity, hospital or other
- Study start
- 15 Apr 2026 (actual)
- Primary completion
- 30 Jun 2026 (actual)
- Study completion
- 1 Sep 2026 (actual)
- First posted
- 29 Sep 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 used a randomized, counterbalanced crossover design to compare high-load chain-based variable-resistance (VR) and free-weight (FW) bench pulls. Resistance-trained men completed two experimental sessions separated by 72 hours, with the order of the VR and FW conditions randomized.
Before each experimental condition, participants completed a standardized general and bench pull-specific warm-up followed by a 10-minute rest period. In each session, participants performed one set of three bench pull repetitions at approximately 85% of their free-weight one-repetition maximum (1RM). In the VR condition, the external resistance was provided by a combination of barbell load and chains, with chains contributing approximately 20% of the effective mean total load. In the FW condition, the external resistance was provided entirely by the barbell.
Following the high-load bench pull, participants rested for 3 minutes and then completed three standardized sets of free-weight bench pulls at approximately 75% 1RM, with 3-minute rest intervals between sets. Each subsequent set was terminated when the mean velocity of a repetition fell below 0.65 m·s-¹ or when the participant was unable to complete the prescribed range of motion.
Direct exercise responses during the high-load bench pulls were assessed using movement velocity and surface electromyography. Residual effects during the subsequent free-weight sets were assessed using repetition count, movement velocity, and surface electromyography. The crossover design allowed each participant to complete both loading conditions and therefore serve as his own control.
Detailed description
This study used a randomized, counterbalanced crossover design to compare the acute effects of high-load chain-based variable resistance (VR) and free-weight (FW) resistance during the bench pull exercise. Resistance-trained men completed both experimental conditions in separate sessions, with the order of conditions randomized and the sessions separated by 72 hours.
Before each experimental condition, participants completed a standardized general warm-up and a bench pull-specific warm-up, followed by a 10-minute rest period. In each session, participants performed one set of three bench pull repetitions at approximately 85% of their free-weight one-repetition maximum (1RM). In the VR condition, external resistance was provided by a combination of barbell load and chains, with chains contributing approximately 20% of the effective mean total load. In the FW condition, external resistance was provided entirely by the barbell.
After the high-load bench pull, participants rested for 3 minutes and then completed three standardized sets of free-weight bench pulls at approximately 75% 1RM, with 3-minute rest intervals between sets. Each subsequent set was terminated when the mean velocity of a repetition fell below 0.65 m·s-¹ or when the participant was unable to complete the prescribed range of motion.
Movement velocity and surface electromyography were recorded during the high-load bench pulls to evaluate direct exercise responses. During the subsequent free-weight sets, repetition count, movement velocity, and surface electromyography were assessed to evaluate residual effects of the preceding high-load condition. The crossover design allowed each participant to complete both loading conditions and therefore serve as his own control.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- Participants completed both high-load variable-resistance and free-weight bench-pull conditions in a randomized, counterbalanced order. The two experimental sessions were separated by 72 hours. Participants assigned to one sequence completed the variable-resistance condition first followed by the free-weight condition, whereas participants assigned to the other sequence completed the conditions in the reverse order.
| Arm | Type | Receives |
|---|---|---|
| Variable Resistance, Then Free Weight | Experimental | Other: High-Load Variable-Resistance Bench Pull, Other: High-Load Free-Weight Bench PullParticipants completed the high-load variable-resistance bench-pull condition during the first experimental session and the high-load free-weight bench-pull condition during the second experimental session. The two sessions were separated by 72 hours. In each session, the high-load bench pull was followed after 3 minutes by three standardized free-weight bench-pull sets at approximately 75% of one-repetition maximum. |
| Free Weight, Then Variable Resistance | Experimental | Other: High-Load Variable-Resistance Bench Pull, Other: High-Load Free-Weight Bench PullParticipants completed the high-load free-weight bench-pull condition during the first experimental session and the high-load variable-resistance bench-pull condition during the second experimental session. The two sessions were separated by 72 hours. In each session, the high-load bench pull was followed after 3 minutes by three standardized free-weight bench-pull sets at approximately 75% of one-repetition maximum. |
Who may qualify
- Ages
- 18 to 30 years
- Sex
- Male only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (8 listed)
- Male adults aged 18-30 years.
- At least 1 year of resistance-training experience.
- Proficiency in the bench-pull technique.
- Bench-pull one-repetition maximum (1RM) of at least 1.0 × body mass.
- No current use of medications that could affect neuromuscular performance.
Key exclusion criteria (3 listed)
- Consumption of caffeine within 12 hours before testing.
- Consumption of alcohol within 24 hours before testing.
- Performance of any upper-body pulling exercise within 48 hours before testing.
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 |
|---|---|---|
| High-Load Variable-Resistance Bench PullParticipants performed one set of three bench-pull repetitions at approximately 85% of their free-weight one-repetition maximum. External resistance was provided by a combination of barbell load and chains, with the chains contributing approximately 20% of the effective mean total load. Participants were instructed to perform the concentric phase with maximal intended velocity. After the high-load bench pull, participants rested for 3 minutes and then completed three standardized free-weight bench-pull sets at approximately 75% of one-repetition maximum, with 3-minute rest intervals between sets. Each subsequent set was terminated when mean repetition velocity fell below 0.65 m·s-¹ or when the prescribed range of motion could not be completed. | Other | Free Weight, Then Variable Resistance, Variable Resistance, Then Free Weight |
| High-Load Free-Weight Bench PullParticipants performed one set of three bench-pull repetitions at approximately 85% of their free-weight one-repetition maximum, with the external resistance provided entirely by the barbell. Participants were instructed to perform the concentric phase with maximal intended velocity. After the high-load bench pull, participants rested for 3 minutes and then completed three standardized free-weight bench-pull sets at approximately 75% of one-repetition maximum, with 3-minute rest intervals between sets. Each subsequent set was terminated when mean repetition velocity fell below 0.65 m·s-¹ or when the prescribed range of motion could not be completed. | Other | Free Weight, Then Variable Resistance, Variable Resistance, Then Free Weight |
Primary outcome
Average Mean and Peak Velocity During the High-Load Bench Pull
Time frame: Day 1 and Day 4, during the high-load bench-pull set
Movement velocity was measured using a linear position transducer sampling at 100 Hz. Mean velocity and peak velocity were obtained for each of the three repetitions performed during the high-load bench-pull set. For each loading condition, average mean velocity and average peak velocity were calculated by averaging the corresponding values across the three repetitions. Velocity was expressed in meters per second (m·s-¹).
Normalized Surface Electromyography Amplitude During the High-Load Bench Pull
Time frame: Day 1 and Day 4, during the high-load bench-pull set
Surface electromyography was recorded from the right latissimus dorsi, teres major, posterior deltoid, and middle trapezius. Root mean square amplitudes were normalized to the maximal root mean square amplitude obtained during maximal voluntary isometric contraction testing and expressed as a percentage of maximal voluntary isometric contraction (%MVIC). Mean and peak electromyography amplitudes were obtained for each repetition and averaged separately across the three high-load repetitions.
Number of Valid Repetitions Completed During Subsequent Free-Weight Bench-Pull Sets
Time frame: Day 1 and Day 4, beginning 3 minutes after the high-load bench-pull set
Participants completed three subsequent free-weight bench-pull sets at approximately 75% of one-repetition maximum. Each set was terminated when the mean velocity of a repetition fell below 0.65 m·s-¹ or when the participant was unable to complete the prescribed range of motion. The number of valid repetitions completed in each of the three sets was recorded.
Movement Velocity During Subsequent Free-Weight Bench-Pull Sets
Time frame: Day 1 and Day 4, beginning 3 minutes after the high-load bench-pull set
Mean and peak velocity were measured during each of the three subsequent free-weight bench-pull sets. For the repetition-matched analysis, velocity outcomes included average velocity, fastest-repetition velocity, matched-final velocity, velocity maintenance, and velocity decline. Repetition matching was performed separately for each participant and corresponding set using the smaller number of valid repetitions completed across the two experimental conditions.
Normalized Surface Electromyography Amplitude During Subsequent Free-Weight Bench-Pull Sets
Time frame: Day 1 and Day 4, beginning 3 minutes after the high-load bench-pull set
Mean and peak surface electromyography amplitudes were assessed for the right latissimus dorsi, teres major, posterior deltoid, and middle trapezius during each of the three subsequent free-weight bench-pull sets. Electromyography amplitudes were normalized to maximal voluntary isometric contraction and expressed as %MVIC. For the repetition-matched analysis, mean and peak amplitudes were averaged separately across all included repetitions within each set.
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 29 Sep 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.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing High-Load Variable-Resistance Bench Pull and High-Load Free-Weight Bench Pull in people with Variable Resistance and Free Weight, run by South China Normal University at 1 site in China.
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 3 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 29 Sep 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 China. 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?
Average Mean and Peak Velocity During the High-Load Bench Pull (time frame: Day 1 and Day 4, during the high-load bench-pull set). The study lists 5 primary outcomes in all. 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 29 Sep 2026.