Isometric Muscle StrengthKRAFTNCT07277335
Neuromuscular Variables and Performance in Mexican Weightlifters
An observational study of Isometric Muscle Strength and Jumping Performance, run by Ángel Rodríguez at 1 site in Mexico.
Trial summary
This study aims to determine whether, within each weight and sex category, higher isometric pull force or greater vertical jump impulse is associated with better final placement in the competition. Read more about this study
- Who is it for?
- Ages 13 to 23 yearsHealthy volunteers can take part
- Conditions the study is for
- Isometric Muscle Strength, Jumping Performance, Weightlifting
- What is being tested?
- Isometric start position pull (ISPP), Vertical impulse and Performance
- How many people
- 50 participants
- Where
- 1 siteMexico
- Study dates
- 27 Dec 2025to 31 Dec 2025
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
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 13 to 23 years
- All sexes
- Healthy volunteers accepted
- Child, Adult
Study population: Weightlifters younger than 15 years old and older than 18 years old (up to 23 years), who will participate in the 2025 edition of the annual national tournament "El Pavo," organized by the Mexican Weightlifting Federation, will be evaluated
Who may be able to join
- Weightlifters younger than 15 years old and older than 18 years old (up to 23 years), registered to compete in the 2025 "El Pavo" National Tournament with no declared health issues.
Who cannot join
- Weightlifters registered for the 2025 "El Pavo" National Tournament who present any declared health issues.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Mexico1 site, 1 recruiting
- Recruiting
Hotel María Dolores
San Luis Potosí City, San Luis Potosí, 78390
Leoncio Moreno Leoncio, Event Coordinator, 8124066707, leo.intensity@gmail.com
About this study
Official title: Association Between Neuromuscular Variables and Competitive Performance in Weightlifting: an Observational Study With Mexican Athletes [The Kraft Project]
This study aims to determine whether, within each weight and sex category, higher isometric pull force or greater vertical jump impulse is associated with better final placement in the competition.
Read the detailed description
This cross-sectional observational study will be conducted during the 2025 "El Pavo" National Tournament, held in San Luis Potosí, Mexico, with athletes officially registered with the Mexican Weightlifting Federation (FMLP). Vertical jump impulse will be assessed using the Deep Squat Jump (DSJ) approximately two hours after each athlete's last valid attempt, followed by the Isometric Pull Start Position (IPSP) test to measure isometric pull force. Competitive performance data-best Snatch (SN), Clean \& Jerk (CJ), and Total (TOT)-will be obtained from official competition records, along with the athlete's final placement within their sex and body mass category.
The study will analyze athletes from two age groups (U-15 and Over-18) and both sexes, selecting one light and one heavy body mass division per group. The included divisions are: U-15, Female: -44 kg (light), -63 kg (heavy) and Male: -56 kg (light), -79 kg (heavy); Over-20, Female: -53 kg (light), -77 kg (heavy) and Male: -65 kg (light), -94 kg (heavy)
- Being tested
- Isometric start position pull (ISPP), Vertical impulse, Performance
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Isometric start position pull (ISPP)Other
The participants' force production capacity will be assessed. The test will be conducted on a force platform. Each athlete will perform general and specific warm-up and familiarization with three isometric attempts with CJ grip (~50%, 80% and 100% perceived effort). For measurement, each participant will execute two 3-s maximum attempts with CJ grip, with 1 minute rest between efforts.
Vertical impulseOther
A force platform will be used to measure the lower-limbs vertical impulse during a The Deep Squat Jump (DSJ). Participants will execute the DSJ without any countermovement, ensuring maintenance of the full squat position for 3-4 seconds before takeoff to avoid any contribution from elastic energy storage.
PerformanceOther
Performance indicators will be obtained from official competition records, extracting the best valid loads in Snatch (SN), Clean \& Jerk (CJ), and Total (TOT)
| Study group | Role | What they receive |
|---|---|---|
| Junior weightlifters younger than 15 years old | Not described Receives: Other: Isometric start position pull (ISPP); Other: Vertical impulse; Other: Performance | |
| Elite weightlifters older than 18 years old (up to 23 years) | Not described Receives: Other: Isometric start position pull (ISPP); Other: Vertical impulse; Other: Performance |
What is being measured
The primary outcome is the main question the study is designed to answer.
Isometric start position pull (ISPP)
The participants' force production capacity will be assessed. The test will be conducted on a force platform
Measured: <5 minutes
Vertical impulse
A force platform will be used to measure the lower-limbs vertical impulse during a The Deep Squat Jump (DSJ)
Measured: <5 minutes
Performance
The final placement of each athlete in their category
Measured: <1 minutes
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted11 Dec 2025
- Study start27 Dec 2025 (estimated)
- Primary completion30 Dec 2025 (estimated)
- Study completion31 Dec 2025 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for Isometric Muscle StrengthStudies 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
- Observational
- Observational model
- Other
- Time perspective
- Cross-sectional
- Enrolment
- 50 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Ángel Rodríguez
- Sponsor type
- Research network
- Responsible party
- Sponsor-investigator, Ángel Rodríguez, Dynamical Business and Science Society - DBSS International SAS
- Investigators
- Diego A Bonilla, Study director, Research Division, Dynamical Business & Science Society-DBSS International SASRodrigo D Merlo, PhD, Study chair, Research Division, Dynamical Business & Science Society-DBSS International SASÁngel Rodríguez-Chávez, Mg, Principal investigator, Research Division, Dynamical Business & Science Society-DBSS International SASJorge L Petro, Study chair, Research Division, Dynamical Business & Science Society-DBSS International SASLeoncio Moreno, Study chair, Federación Mexicana de Levantamiento de PesasShyam Chavda, Study chair, London Sports Institute, Middlesex University, West Stand, Stone X Stadium, Greenlands Lane, London NW4 1RL, UKMarcos A Soriano, Study chair, Centre for Sport Studies, Rey Juan Carlos University, 28943 Madrid, Spain; miguel.delolmo@urjc.es
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07277335
- Sponsor's protocol ID
- Kraft2025_DBSS
- Other IDs
- Kraft2025_DBSS
- Acronym
- KRAFT
- Status last verified
- Dec 2025
- First submitted
- 26 Nov 2025
- Last updated
- 11 Dec 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Joffe SA, Chavda S, Gilham J, Sandercock GRH, Tallent J. A comparison of maximal isometric force in the first pull, transition and second pull of the clean and their contribution to predict performance in national and international level weightlifters. Sports Biomech. 2026 Feb;25(2):281-297. doi: 10.1080/14763141.2025.2458478. Epub 2025 Jan 30.
PubMed 39882780Soriano MA, Flores FJ, Alonso-Aubin DA, Garcia-Sanchez C, Ceniza-Villacastin JA, Jimenez-Ormeno E, Lama-Arenales J, Comfort P. Associations Between Maximum Isometric Strength and Weightlifting Performance in Youth Weightlifters. J Strength Cond Res. 2025 May 1;39(5):570-578. doi: 10.1519/JSC.0000000000005052.
PubMed 40266638Vizcaya FJ, Viana O, del Olmo MF, Acero RM. Could the deep squat jump predict weightlifting performance? J Strength Cond Res. 2009 May;23(3):729-34. doi: 10.1519/JSC.0b013e3181a04dc3.
PubMed 19387408
Study at a glance
From the registry record, last updated by the sponsor on 11 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Association Between Neuromuscular Variables and Competitive Performance in Weightlifting: an Observational Study With Mexican Athletes [The Kraft Project]
- ClinicalTrials.gov ID
- NCT07277335
- Acronym / sponsor ID
- KRAFT / Kraft2025_DBSS
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 50 participants (estimated)
- Lead sponsor
- Ángel RodríguezResearch network
- Study start
- 27 Dec 2025 (estimated)
- Primary completion
- 30 Dec 2025 (estimated)
- Study completion
- 31 Dec 2025 (estimated)
- First posted
- 11 Dec 2025 (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 aims to determine whether, within each weight and sex category, higher isometric pull force or greater vertical jump impulse is associated with better final placement in the competition.
Detailed description
This cross-sectional observational study will be conducted during the 2025 "El Pavo" National Tournament, held in San Luis Potosí, Mexico, with athletes officially registered with the Mexican Weightlifting Federation (FMLP). Vertical jump impulse will be assessed using the Deep Squat Jump (DSJ) approximately two hours after each athlete's last valid attempt, followed by the Isometric Pull Start Position (IPSP) test to measure isometric pull force. Competitive performance data-best Snatch (SN), Clean \& Jerk (CJ), and Total (TOT)-will be obtained from official competition records, along with the athlete's final placement within their sex and body mass category.
The study will analyze athletes from two age groups (U-15 and Over-18) and both sexes, selecting one light and one heavy body mass division per group. The included divisions are: U-15, Female: -44 kg (light), -63 kg (heavy) and Male: -56 kg (light), -79 kg (heavy); Over-20, Female: -53 kg (light), -77 kg (heavy) and Male: -65 kg (light), -94 kg (heavy)
Study design
- Observational model
- Other
- Time perspective
- Cross-sectional
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Junior weightlifters younger than 15 years old | – | Other: Isometric start position pull (ISPP), Other: Vertical impulse, Other: Performance |
| Elite weightlifters older than 18 years old (up to 23 years) | – | Other: Isometric start position pull (ISPP), Other: Vertical impulse, Other: Performance |
Who may qualify
- Ages
- 13 to 23 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult
- Study population
- Weightlifters younger than 15 years old and older than 18 years old (up to 23 years), who will participate in the 2025 edition of the annual national tournament "El Pavo," organized by the Mexican Weightlifting Federation, will be evaluated
Key inclusion criteria (1 listed)
- Weightlifters younger than 15 years old and older than 18 years old (up to 23 years), registered to compete in the 2025 "El Pavo" National Tournament with no declared health issues.
Key exclusion criteria (1 listed)
- Weightlifters registered for the 2025 "El Pavo" National Tournament who present any declared health issues.
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 start position pull (ISPP)The participants' force production capacity will be assessed. The test will be conducted on a force platform. Each athlete will perform general and specific warm-up and familiarization with three isometric attempts with CJ grip (~50%, 80% and 100% perceived effort). For measurement, each participant will execute two 3-s maximum attempts with CJ grip, with 1 minute rest between efforts. | Other | Elite weightlifters older than 18 years old (up to 23 years), Junior weightlifters younger than 15 years old |
| Vertical impulseA force platform will be used to measure the lower-limbs vertical impulse during a The Deep Squat Jump (DSJ). Participants will execute the DSJ without any countermovement, ensuring maintenance of the full squat position for 3-4 seconds before takeoff to avoid any contribution from elastic energy storage. | Other | Elite weightlifters older than 18 years old (up to 23 years), Junior weightlifters younger than 15 years old |
| PerformancePerformance indicators will be obtained from official competition records, extracting the best valid loads in Snatch (SN), Clean \& Jerk (CJ), and Total (TOT) | Other | Elite weightlifters older than 18 years old (up to 23 years), Junior weightlifters younger than 15 years old |
Primary outcome
Isometric start position pull (ISPP)
Time frame: <5 minutes
The participants' force production capacity will be assessed. The test will be conducted on a force platform
Vertical impulse
Time frame: <5 minutes
A force platform will be used to measure the lower-limbs vertical impulse during a The Deep Squat Jump (DSJ)
Performance
Time frame: <1 minutes
The final placement of each athlete in their category
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 Dec 2025.
- Background: PubMed 39882780Joffe SA, Chavda S, Gilham J, Sandercock GRH, Tallent J. A comparison of maximal isometric force in the first pull, transition and second pull of the clean and their contribution to predict performance in national and international level weightlifters. Sports Biomech. 2026 Feb;25(2):281-297. doi: 10.1080/14763141.2025.2458478. Epub 2025 Jan 30.
- Background: PubMed 40266638Soriano MA, Flores FJ, Alonso-Aubin DA, Garcia-Sanchez C, Ceniza-Villacastin JA, Jimenez-Ormeno E, Lama-Arenales J, Comfort P. Associations Between Maximum Isometric Strength and Weightlifting Performance in Youth Weightlifters. J Strength Cond Res. 2025 May 1;39(5):570-578. doi: 10.1519/JSC.0000000000005052.
- Background: PubMed 19387408Vizcaya FJ, Viana O, del Olmo MF, Acero RM. Could the deep squat jump predict weightlifting performance? J Strength Cond Res. 2009 May;23(3):729-34. doi: 10.1519/JSC.0b013e3181a04dc3.
- Individual participant dataSharing planned: No
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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.
Diego A Bonilla study director
Research Division, Dynamical Business & Science Society-DBSS International SAS
Rodrigo D Merlo, PhD study chair
Research Division, Dynamical Business & Science Society-DBSS International SAS
Ángel Rodríguez-Chávez, Mg principal investigator
Research Division, Dynamical Business & Science Society-DBSS International SAS
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Isometric Muscle Strength and Jumping Performance, run by Ángel Rodríguez at 1 site in Mexico.
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 1 inclusion and 1 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: looking for participants now, as of the sponsor's last update on 11 Dec 2025. 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 Mexico. 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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Each site lists its own contact: choose the nearest one under Trial locations. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Isometric start position pull (ISPP) (time frame: <5 minutes). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07277335, which also lists 3 linked publications.
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 11 Dec 2025.