Athletic PerformanceNCT07853235
Core Stability Training and Breaststroke Performance in University Students Learning to Swim
A study testing Isometric Core-Stability Training and Low-Intensity Stretching and Relaxation in people with Athletic Performance, run by Rongxuan Hu at 1 site in China.
Trial summary
The purpose of this study was to find out whether adding core stability exercises to regular swimming lessons could improve breaststroke performance in university students learning to swim. These exercises involve holding the body in set positions to train muscles that help maintain posture and stability. Read more about this study
- Who is it for?
- Ages 18 to 20 yearsHealthy volunteers can take part
- Conditions the study is for
- Athletic Performance
- What is being tested?
- Isometric Core-Stability Training and Low-Intensity Stretching and Relaxation
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 136 participants
- Where
- 1 siteChina
- Study dates
- 27 Feb 2026to 24 Jun 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 20 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- University students aged 18 to 20 years enrolled in the compulsory swimming course at Chongqing College of Mobile Communication.
- Beginner breaststroke swimmers or non-swimmers with no history of systematic swimming training.
- In good health, with no disease or injury that would prevent participation in regular physical education, swimming lessons, or low- to moderate-intensity land-based isometric exercise.
- Able to understand the study information and willing to provide written informed consent.
- Available to participate in the intervention during course Weeks 2 through 15 and the scheduled assessments in Week 16.
Who cannot join
- Recent bone, joint, muscle, or ligament injury, or another condition that makes aquatic activity or land-based support exercises unsuitable.
- Participation in additional swimming-specific training at least twice per week, or membership on a university or departmental sports team.
- A chronic disease or acute health condition for which a physician has explicitly advised avoiding swimming or resistance/isometric exercise.
Trial locations and contacts
1 site in 1 country.
China1 site
Chongqing College of Mobile Communication
Chongqing, Chongqing Municipality, 401420
About this study
Official title: Effects of 14-Week Supplementary Isometric Core-Stability Training on Breaststroke Efficiency in Beginner College Swimmers: An Assessor- and Analyst-Blinded Randomized Controlled Trial
The purpose of this study was to find out whether adding core stability exercises to regular swimming lessons could improve breaststroke performance in university students learning to swim. These exercises involve holding the body in set positions to train muscles that help maintain posture and stability.
The study included 136 university students aged 18 to 20 years. Participants were assigned by chance to one of two groups. Both groups attended the same 90-minute breaststroke lesson each week. After each lesson, one group completed 30 minutes of core stability exercises, while the other group completed 30 minutes of low-intensity stretching and relaxation activities. These additional sessions took place once a week for 14 weeks.
The main comparison was the time needed to swim 25 meters using breaststroke after the training period. Other assessments measured kicking performance, the number of swimming strokes, distance traveled per stroke, and muscle endurance during exercises performed on land.
Read the detailed description
The study was conducted within a 16-week university swimming course. Baseline assessments took place during Weeks 1 and 2, and the supplementary activities were delivered during Weeks 2 through 15. Postintervention testing was scheduled for Week 16. Participants who could not complete testing at that time could attend a prespecified makeup session in Week 17 using the same assessment procedures.
Because participants were beginner swimmers, baseline water skills were assessed using face immersion and breathing control, streamlined gliding distance, and distance traveled while kicking with a kickboard. These measures characterized initial water ability; the complete 25-meter breaststroke performance test was conducted after the intervention. Land-based muscle endurance was assessed at baseline and after the intervention.
Outcome assessors and data analysts were blinded to group assignment. Attendance and adverse events were recorded during the intervention. The study also explored whether the effects of the intervention differed between male and female participants.
- Conditions
- Athletic Performance
- Being tested
- Isometric Core-Stability Training, Low-Intensity Stretching and Relaxation
- Keywords
- Swimming, Breaststroke, Core Stability, Isometric Exercise, Muscular Endurance, Novice Swimmers, University Students
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Isometric Core-Stability TrainingBehavioural
A 30-minute supplementary exercise session delivered once weekly for 14 weeks during Weeks 2 through 15, immediately after the routine breaststroke lesson. The program comprised six isometric exercises: wall sit, side bridge, dead bug hold, single-leg glute bridge hold, Bulgarian split squat hold, and standard plank.
Low-Intensity Stretching and RelaxationBehavioural
A 30-minute supplementary session of low-intensity stretching, breathing relaxation, and cool-down activities delivered once weekly for 14 weeks during Weeks 2 through 15, immediately after the routine breaststroke lesson. Session frequency and duration were matched to those of the experimental group.
| Study group | Role | What they receive |
|---|---|---|
| Isometric Core-Stability Training | Experimental | Participants attended a 90-minute beginner breaststroke lesson once weekly within a 16-week university swimming course. In addition, they completed 30 minutes of isometric core-stability training immediately after each lesson during Weeks 2 through 15, for a total of 14 supplementary sessions. Receives: Behavioral: Isometric Core-Stability Training |
| Stretching and Relaxation | Active comparator | Participants attended the same 90-minute beginner breaststroke lesson once weekly within a 16-week university swimming course. In addition, they completed 30 minutes of low-intensity stretching, breathing relaxation, and cool-down activities immediately after each lesson during Weeks 2 through 15, for a total of 14 time-matched supplementary sessions. Receives: Behavioral: Low-Intensity Stretching and Relaxation |
What is being measured
The primary outcome is the main question the study is designed to answer.
25-Meter Breaststroke Swimming Time
The fastest valid time, in seconds, to complete a 25-meter swim using coordinated breaststroke after the intervention. Lower values indicate better swimming performance.
Measured: Postintervention at course Week 16, with prespecified makeup testing at Week 17 if needed.
Secondary outcomes (9)
25-Meter Breaststroke Kick-Only Swimming Time
The fastest valid time, in seconds, from two 25-meter breaststroke kick-only trials after the intervention. Two blinded timekeepers independently timed each trial, with video adjudication when their readings differed by more than 0.30 second. Lower values indicate better kicking performance.
Measured: Postintervention at course Week 16, with prespecified makeup testing at Week 17 if needed.
Breaststroke Stroke Count Over 25 Meters
The number of complete breaststroke cycles used to swim 25 meters after the intervention. Two blinded observers independently counted the strokes, and disagreements were resolved from the corresponding video by a third blinded reviewer.
Measured: Postintervention at course Week 16, with prespecified makeup testing at Week 17 if needed.
Derived Breaststroke Stroke Length
Average distance traveled per complete breaststroke cycle, calculated as 25 meters divided by the adjudicated stroke count for the 25-meter breaststroke swim. The result is expressed in meters per stroke. Higher values indicate a greater distance traveled per stroke.
Measured: Postintervention at course Week 16, with prespecified makeup testing at Week 17 if needed.
Wall-Sit Hold Time
Duration, in seconds, of a single wall-sit hold, assessed at baseline and after the intervention. Timing ended when the participant could no longer maintain the prescribed position or voluntarily stopped. Longer hold times indicate better performance.
Measured: Baseline during course Weeks 1-2 and postintervention at course Week 16, with prespecified makeup testing at Week 17 if needed.
Side-Bridge Hold Time
Mean duration, in seconds, of the left- and right-side bridge holds, assessed at baseline and after the intervention. Each hold ended when the participant could no longer maintain the prescribed position or voluntarily stopped. Longer mean hold times indicate better performance.
Measured: Baseline during course Weeks 1-2 and postintervention at course Week 16, with prespecified makeup testing at Week 17 if needed.
Dead-Bug Hold Score
Dead-bug hold performance assessed at baseline and after the intervention using a total score ranging from 0 to 3 points. Three positions were assessed: the starting position, the right-arm/left-leg position, and the left-arm/right-leg position. Each position received 1 point if maintained correctly for 15 seconds and 0 points otherwise. The three scores were summed. Higher total scores indicate better performance.
Measured: Baseline during course Weeks 1-2 and postintervention at course Week 16, with prespecified makeup testing at Week 17 if needed.
Single-Leg Glute-Bridge Hold Time
Mean duration, in seconds, of the left- and right-leg glute-bridge holds, assessed at baseline and after the intervention. Each hold ended when the participant could no longer maintain the prescribed position or voluntarily stopped. Longer mean hold times indicate better performance.
Measured: Baseline during course Weeks 1-2 and postintervention at course Week 16, with prespecified makeup testing at Week 17 if needed.
Bulgarian Split-Squat Hold Time
Mean duration, in seconds, of the left- and right-side Bulgarian split-squat holds, assessed at baseline and after the intervention. Each hold ended when the participant could no longer maintain the prescribed position or voluntarily stopped. Longer mean hold times indicate better performance.
Measured: Baseline during course Weeks 1-2 and postintervention at course Week 16, with prespecified makeup testing at Week 17 if needed.
Standard Plank Hold Time
Duration, in seconds, of a single standard plank hold, assessed at baseline and after the intervention. Timing ended when the participant could no longer maintain the prescribed position or voluntarily stopped. Longer hold times indicate better performance.
Measured: Baseline during course Weeks 1-2 and postintervention at course Week 16, with prespecified makeup testing at Week 17 if needed.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Oct 2026
- Study start27 Feb 2026
- Primary completion24 Jun 2026
- Study completion24 Jun 2026
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
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Single-center, two-arm, parallel-group randomized controlled trial. Participants were individually randomized in a 1:1 ratio, stratified by sex, to supplementary isometric core-stability training or time-matched low-intensity stretching and relaxation. Both groups received the same routine breaststroke instruction.
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 136 participants (actual)
Sponsor and investigators
- Lead sponsor
- Rongxuan Hu
- Sponsor type
- University, hospital or other
- Collaborators
- Chongqing College of Mobile Communication
- Responsible party
- Sponsor-investigator, Rongxuan Hu, Chongqing College of Mobile Communication
- Investigators
- Rongxuan Hu, Principal investigator, Chongqing College of Mobile Communication
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07853235
- Sponsor's protocol ID
- CQYTXY2026011501
- Status last verified
- Sep 2026
- First submitted
- 26 Sep 2026
- Last updated
- 5 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Deidentified individual participant data underlying the published study results, together with a data dictionary, will be deposited in Science Data Bank (ScienceDB) and made available through controlled access. The shared dataset will include the baseline characteristics, group allocation, and outcome measurements needed to reproduce the reported analyses. Direct identifiers, the participant identification key, signed consent forms, and identifiable recordings will not be shared.
Study at a glance
From the registry record, last updated by the sponsor on 5 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of 14-Week Supplementary Isometric Core-Stability Training on Breaststroke Efficiency in Beginner College Swimmers: An Assessor- and Analyst-Blinded Randomized Controlled Trial
- ClinicalTrials.gov ID
- NCT07853235
- Acronym / sponsor ID
- CQYTXY2026011501
- Conditions
- Athletic Performance
- Keywords
- Swimming, Breaststroke, Core Stability, Isometric Exercise, Muscular Endurance, Novice Swimmers, University Students
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 136 participants (actual)
- Lead sponsor
- Rongxuan HuUniversity, hospital or other
- Collaborators
- Chongqing College of Mobile Communication
- Study start
- 27 Feb 2026 (actual)
- Primary completion
- 24 Jun 2026 (actual)
- Study completion
- 24 Jun 2026 (actual)
- First posted
- 1 Oct 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.
The purpose of this study was to find out whether adding core stability exercises to regular swimming lessons could improve breaststroke performance in university students learning to swim. These exercises involve holding the body in set positions to train muscles that help maintain posture and stability.
The study included 136 university students aged 18 to 20 years. Participants were assigned by chance to one of two groups. Both groups attended the same 90-minute breaststroke lesson each week. After each lesson, one group completed 30 minutes of core stability exercises, while the other group completed 30 minutes of low-intensity stretching and relaxation activities. These additional sessions took place once a week for 14 weeks.
The main comparison was the time needed to swim 25 meters using breaststroke after the training period. Other assessments measured kicking performance, the number of swimming strokes, distance traveled per stroke, and muscle endurance during exercises performed on land.
Detailed description
The study was conducted within a 16-week university swimming course. Baseline assessments took place during Weeks 1 and 2, and the supplementary activities were delivered during Weeks 2 through 15. Postintervention testing was scheduled for Week 16. Participants who could not complete testing at that time could attend a prespecified makeup session in Week 17 using the same assessment procedures.
Because participants were beginner swimmers, baseline water skills were assessed using face immersion and breathing control, streamlined gliding distance, and distance traveled while kicking with a kickboard. These measures characterized initial water ability; the complete 25-meter breaststroke performance test was conducted after the intervention. Land-based muscle endurance was assessed at baseline and after the intervention.
Outcome assessors and data analysts were blinded to group assignment. Attendance and adverse events were recorded during the intervention. The study also explored whether the effects of the intervention differed between male and female participants.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
- Model description
- Single-center, two-arm, parallel-group randomized controlled trial. Participants were individually randomized in a 1:1 ratio, stratified by sex, to supplementary isometric core-stability training or time-matched low-intensity stretching and relaxation. Both groups received the same routine breaststroke instruction.
| Arm | Type | Receives |
|---|---|---|
| Isometric Core-Stability Training | Experimental | Behavioral: Isometric Core-Stability TrainingParticipants attended a 90-minute beginner breaststroke lesson once weekly within a 16-week university swimming course. In addition, they completed 30 minutes of isometric core-stability training immediately after each lesson during Weeks 2 through 15, for a total of 14 supplementary sessions. |
| Stretching and Relaxation | Active comparator | Behavioral: Low-Intensity Stretching and RelaxationParticipants attended the same 90-minute beginner breaststroke lesson once weekly within a 16-week university swimming course. In addition, they completed 30 minutes of low-intensity stretching, breathing relaxation, and cool-down activities immediately after each lesson during Weeks 2 through 15, for a total of 14 time-matched supplementary sessions. |
Who may qualify
- Ages
- 18 to 20 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- University students aged 18 to 20 years enrolled in the compulsory swimming course at Chongqing College of Mobile Communication.
- Beginner breaststroke swimmers or non-swimmers with no history of systematic swimming training.
- In good health, with no disease or injury that would prevent participation in regular physical education, swimming lessons, or low- to moderate-intensity land-based isometric exercise.
- Able to understand the study information and willing to provide written informed consent.
- Available to participate in the intervention during course Weeks 2 through 15 and the scheduled assessments in Week 16.
Key exclusion criteria (3 listed)
- Recent bone, joint, muscle, or ligament injury, or another condition that makes aquatic activity or land-based support exercises unsuitable.
- Participation in additional swimming-specific training at least twice per week, or membership on a university or departmental sports team.
- A chronic disease or acute health condition for which a physician has explicitly advised avoiding swimming or resistance/isometric exercise.
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 |
|---|---|---|
| Isometric Core-Stability TrainingA 30-minute supplementary exercise session delivered once weekly for 14 weeks during Weeks 2 through 15, immediately after the routine breaststroke lesson. The program comprised six isometric exercises: wall sit, side bridge, dead bug hold, single-leg glute bridge hold, Bulgarian split squat hold, and standard plank. | Behavioural | Isometric Core-Stability Training |
| Low-Intensity Stretching and RelaxationA 30-minute supplementary session of low-intensity stretching, breathing relaxation, and cool-down activities delivered once weekly for 14 weeks during Weeks 2 through 15, immediately after the routine breaststroke lesson. Session frequency and duration were matched to those of the experimental group. | Behavioural | Stretching and Relaxation |
Primary outcome
25-Meter Breaststroke Swimming Time
Time frame: Postintervention at course Week 16, with prespecified makeup testing at Week 17 if needed.
The fastest valid time, in seconds, to complete a 25-meter swim using coordinated breaststroke after the intervention. Lower values indicate better swimming performance.
9 secondary outcomes
25-Meter Breaststroke Kick-Only Swimming Time
Time frame: Postintervention at course Week 16, with prespecified makeup testing at Week 17 if needed.
Breaststroke Stroke Count Over 25 Meters
Time frame: Postintervention at course Week 16, with prespecified makeup testing at Week 17 if needed.
Derived Breaststroke Stroke Length
Time frame: Postintervention at course Week 16, with prespecified makeup testing at Week 17 if needed.
Wall-Sit Hold Time
Time frame: Baseline during course Weeks 1-2 and postintervention at course Week 16, with prespecified makeup testing at Week 17 if needed.
Side-Bridge Hold Time
Time frame: Baseline during course Weeks 1-2 and postintervention at course Week 16, with prespecified makeup testing at Week 17 if needed.
Dead-Bug Hold Score
Time frame: Baseline during course Weeks 1-2 and postintervention at course Week 16, with prespecified makeup testing at Week 17 if needed.
Single-Leg Glute-Bridge Hold Time
Time frame: Baseline during course Weeks 1-2 and postintervention at course Week 16, with prespecified makeup testing at Week 17 if needed.
Bulgarian Split-Squat Hold Time
Time frame: Baseline during course Weeks 1-2 and postintervention at course Week 16, with prespecified makeup testing at Week 17 if needed.
Standard Plank Hold Time
Time frame: Baseline during course Weeks 1-2 and postintervention at course Week 16, with prespecified makeup testing at Week 17 if needed.
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 5 Oct 2026.
- Individual participant dataSharing planned: Yes. Deidentified individual participant data underlying the published study results, together with a data dictionary, will be deposited in Science Data Bank (ScienceDB) and made available through controlled access. The shared dataset will include the baseline characteristics, group allocation, and outcome measurements needed to reproduce the reported analyses. Direct identifiers, the participant identification key, signed consent forms, and identifiable recordings will not be shared.
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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.
Rongxuan Hu principal investigator
Chongqing College of Mobile Communication
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Isometric Core-Stability Training and Low-Intensity Stretching and Relaxation in people with Athletic Performance, run by Rongxuan Hu 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 5 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 5 Oct 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?
25-Meter Breaststroke Swimming Time (time frame: Postintervention at course Week 16, with prespecified makeup testing at Week 17 if needed.). 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 5 Oct 2026.