ChildrenNCT07552844
Effects of 8-Week CrossFit-Based Concurrent Training on Fitness, Body Composition, and Psychological Outcomes in Schoolchildren
A study testing CrossFit training in people with Children and Crossfit, run by Maimónides Biomedical Research Institute of Córdoba at 1 site in Spain.
Trial summary
This study examines the effects of an 8-week CrossFit-based concurrent training program in boys and girls aged 7 to 11 years, comparing an experimental group (n=15) with a control group (n=15). Read more about this study
- Who is it for?
- Ages 7 to 11 yearsHealthy volunteers can take part
- Conditions the study is for
- Children, Crossfit, Psychology, Child
- What is being tested?
- CrossFit training
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 30 participants
- Where
- 1 siteSpain
- Study dates
- Jun 2026to Jul 2026
- Phase
- Interventional
- 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 7 to 11 years
- All sexes
- Healthy volunteers accepted
- Child
Who may be able to join
- Age: 7-11 years.
- Students enrolled at CEIP Pablo García Baena (Córdoba).
- For the experimental group:
- Availability to attend the Triple XXX Box (Polígono Pedroches, C. los Alfareros, Parcel 119, 14014 Córdoba), where both assessments and training sessions will be conducted.
- Availability to attend training sessions twice per week for the 8-week intervention period.
- No participation in extracurricular physical activity prior to the start of the CrossFit program.
- For the control group:
- No participation in extracurricular physical activity. Informed consent signed by parents or legal guardians. No medical, psychological, or behavioral contraindications that would prevent participation in physical activity.
Who cannot join
- Children with musculoskeletal injuries, diseases, or medical, psychological, or behavioral conditions that limit physical activity or interfere with the assessment of outcomes.
- Inability or anticipated difficulty in regularly attending training sessions.
- Refusal of parents or legal guardians to provide informed consent.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
About this study
Official title: Effects of an 8-Week CrossFit-Based Concurrent Training Program on Physical Fitness, Body Composition, and Psychological Outcomes in Schoolchildren: A Randomized Controlled Trial Protocol
This study examines the effects of an 8-week CrossFit-based concurrent training program in boys and girls aged 7 to 11 years, comparing an experimental group (n=15) with a control group (n=15). The aim is to assess changes in strength, cardiorespiratory fitness, body composition, and psychological variables such as anxiety, stress, and self-esteem, using field-based physical tests (CMJ, Course Navette, handgrip strength, etc.) and validated questionnaires. The study follows a randomized controlled trial design with pre- and post-intervention assessments. The experimental group will complete two weekly CrossFit sessions adapted for children, while the control group will maintain their usual routine without structured physical training. The hypothesis states that the intervention will significantly improve both physical performance and psychological well-being in the experimental group compared to the control group.
Read the detailed description
This study is a randomized controlled trial designed to examine the effects of an 8-week CrossFit-based concurrent training program on both physical fitness and psychological well-being in school-aged children (boys and girls aged 7 to 11 years). The sample will be drawn from a primary school in Córdoba (Spain) and will be randomly assigned to either an experimental group (n=15) or a control group (n=15).
The experimental group will participate in a supervised CrossFit Kids program, consisting of two weekly sessions of 50 minutes each. These sessions will include functional, age-appropriate high-intensity exercises structured into four parts: warm-up (mobility and games), strength work (technical and developmental exercises), metabolic conditioning (METCON), and a final cool-down or game-based activity. The control group will continue with their usual daily routine without any structured physical training during the intervention period.
The study will assess changes in physical fitness variables, including muscular strength (countermovement jump, handgrip strength, standing long jump, and medicine ball throw), cardiorespiratory fitness (Course Navette test, burpees, abdominal endurance tests, and step tests), and body composition indicators such as BMI, waist circumference, and waist-to-height ratio. In addition, psychological outcomes will be evaluated using validated instruments measuring state and trait anxiety (State-Trait Anxiety Inventory), daily stress (Children's Daily Stress Inventory) and self-esteem (Rosenberg Self-Esteem Scale).
Measurements will be taken before and after the intervention to compare intra- and inter-group changes. The study also explores potential relationships between improvements in physical fitness and psychological outcomes.
The main hypothesis is that participation in the CrossFit-based concurrent training program will lead to significant improvements in strength, endurance, body composition, and psychological well-being (reduced anxiety and stress and improved self-esteem) compared to the control group, highlighting the potential of this training approach as an effective and comprehensive intervention for children.
- Conditions
- Children, Crossfit, Psychology, Child, Physical Fitness, Body Composition
- Being tested
- CrossFit training
- Keywords
- children, stress, anxiety, exercise training, crossfit, self-esteem, Physical Fitness, body composition
- Medical subject headings
- Anxiety Disorders
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
CrossFit trainingOther
Also called Body composition, Psychological Outcomes
The experimental arm will receive an 8-week concurrent training intervention based on a CrossFit program adapted for children, with a frequency of two 50-minute sessions per week. Each session will be structured into a warm-up (mobility exercises and games), strength training (technical and functional exercises), metabolic conditioning (METCON), and a cool-down phase. The program will be supervised by qualified professionals to ensure safety and proper execution of the exercises.
| Study group | Role | What they receive |
|---|---|---|
| Crossfit training | Experimental | Not described Receives: Other: CrossFit training |
| Control | No intervention | The control arm will not receive any structured exercise intervention during the study period and will continue with their usual daily school routine. This will allow comparison of changes in physical and psychological outcomes between both groups. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Countermovement Jump Test (CMJ) - Explosive Strength Test
The countermovement jump (CMJ), is used to assess explosive strength of the lower limbs. In this test, participants begin in an upright standing position with their hands placed on their hips to avoid arm swing contribution. They are instructed to perform a maximal vertical jump following a rapid downward countermovement, descending to approximately 90° of knee flexion, and then immediately jumping as high as possible.
Measured: Week 1 (Day 1), Week 8 (Day 16)
Standing Long Jump
This test consists of performing a horizontal jump using both feet simultaneously, starting from the same level. A preliminary jump is not allowed. The maximum horizontal distance achieved is recorded, measuring from the starting line to the rearmost point of the shoe closest to that line. Upon landing, the participant must maintain balance and remain stationary.
Measured: Week 1 (Day 1), Week 8 (Day 16)
Medicine Ball Throw Test
The medicine ball throw test (2 kg) is performed from an upright standing position, holding the ball with both hands above the head. Participants are required to throw the ball as far as possible by performing a flexion-extension movement of the legs, with or without trunk extension.
Measured: Week 1 (Day 1), Week 8 (Day 16)
20 m Shuttle Run Test (Course-Navette)
In the 20 m shuttle run test, participants run back and forth between two lines set 20 m apart, with progressively increasing speed. The initial running speed is 8.5 km/h and increases by 0.5 km/h every minute. Each increase in speed corresponds to a new level.
Measured: Week 1 (Day 1), Week 8 (Day 16)
Plank Hold Time
The plank protocol requires participants to maintain a static prone position, with only the forearms and toes in contact with the ground. Proper form requires feet together with toes pointing downward, elbows positioned under the shoulders at forearm width, and hands clasped together on the floor.
Measured: Week 1 (Day 1), Week 8 (Day 16)
Burpess
To perform a burpee, participants begin with feet shoulder-width apart and lower into a squat by bending the knees. They then place their palms on the floor and jump back into a plank position with arms extended, ensuring hands face forward, feet rest on the toes, and the back remains straight. Next, they perform a push-up by bending the elbows and returning to the plank position. Then, they jump forward into a squat position, keeping hands on the ground, hips lowered, thighs parallel to the floor, and knees positioned between the elbows. Finally, they jump vertically from the squat position, extending the arms overhead during the jump.
Measured: Week 1 (Day 1), Week 8 (Day 16)
Step Test
This test consists of stepping up and down on a platform approximately 30 cm in height, maintaining a constant speed and rhythm.
Measured: Week 1 (Day 1), Week 8 (Day 16)
State-Trait Anxiety Inventory for Children
State-Trait Anxiety Inventory for Children is a psychological instrument designed to measure two dimensions of anxiety in children: state anxiety, referring to temporary or situational anxiety, and trait anxiety, which assesses the general tendency to experience anxiety.
Measured: Week 1 (Day 1), Week 8 (Day 16)
Children's Daily Stress Inventory
This test aims to assess daily stress in children by evaluating how common experiences, such as school, family, and social issues, contribute to stress levels.
Measured: Week 1 (Day 1), Week 8 (Day 16)
Rosenberg Self-Esteem Scale
The Rosenberg Self-Esteem Scale assesses an individual's self-worth through a series of statements reflecting overall self-evaluation.
Measured: Week 1 (Day 1), Week 8 (Day 16)
Secondary outcomes (2)
Body composition
Body composition will be assessed using bioelectrical impedance analysis, with particular emphasis on body fat percentage. Measurements will be conducted in accordance with the protocol established by the International Society for the Advancement of Kinanthropometry (ISAK).
Measured: Week 1 (Day 1), Week 8 (Day 16)
Perceived Exertion
Perceived exertion will be measured using a pictorial and verbal category-ratio scale designed for children.
Measured: Week 1 (Day 1), Week 8 (Day 16)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted27 Apr 2026
- Study startJun 2026 (estimated)
- Primary completionJun 2026 (estimated)
- Study completionJul 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for ChildrenStudies 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
- Non-randomised
- Intervention model
- Parallel groups
- Model description
- Randomized clinical trial
- Masking
- None (open label)
- Enrolment
- 30 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Maimónides Biomedical Research Institute of Córdoba
- Sponsor type
- University, hospital or other
- Collaborators
- Universidad de Córdoba, Escuela Universitaria de Osuna
- Responsible party
- Principal investigator, Jose Manuel Jurado Castro, Maimónides Biomedical Research Institute of Córdoba
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07552844
- Sponsor's protocol ID
- SICEIA-2025-000408
- Status last verified
- Apr 2026
- First submitted
- 20 Apr 2026
- Last updated
- 30 Apr 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Duran-Lopez N, Gomez-Garcia C, Ranchal-Sanchez A, Lucena-Jurado V, Moyano-Ortega V, Lara-Barahona Ostos A, Jurado-Castro JM. High-Intensity Functional Concurrent Training for Physical Fitness, Body Composition, and Psychological Outcomes in Schoolchildren: Protocol for a Randomized Controlled Trial. Sports (Basel). 2026 Jul 3;14(7):279. doi: 10.3390/sports14070279.
PubMed 42506821
Study at a glance
From the registry record, last updated by the sponsor on 30 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of an 8-Week CrossFit-Based Concurrent Training Program on Physical Fitness, Body Composition, and Psychological Outcomes in Schoolchildren: A Randomized Controlled Trial Protocol
- ClinicalTrials.gov ID
- NCT07552844
- Acronym / sponsor ID
- SICEIA-2025-000408
- Conditions
- Children, Crossfit, Psychology, Child, Physical Fitness, Body Composition
- Keywords
- children, stress, anxiety, exercise training, crossfit, self-esteem, Physical Fitness, body composition
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 30 participants (estimated)
- Lead sponsor
- Maimónides Biomedical Research Institute of CórdobaUniversity, hospital or other
- Collaborators
- Universidad de Córdoba, Escuela Universitaria de Osuna
- Study start
- Jun 2026 (estimated)
- Primary completion
- Jun 2026 (estimated)
- Study completion
- Jul 2026 (estimated)
- First posted
- 27 Apr 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 examines the effects of an 8-week CrossFit-based concurrent training program in boys and girls aged 7 to 11 years, comparing an experimental group (n=15) with a control group (n=15). The aim is to assess changes in strength, cardiorespiratory fitness, body composition, and psychological variables such as anxiety, stress, and self-esteem, using field-based physical tests (CMJ, Course Navette, handgrip strength, etc.) and validated questionnaires. The study follows a randomized controlled trial design with pre- and post-intervention assessments. The experimental group will complete two weekly CrossFit sessions adapted for children, while the control group will maintain their usual routine without structured physical training. The hypothesis states that the intervention will significantly improve both physical performance and psychological well-being in the experimental group compared to the control group.
Detailed description
This study is a randomized controlled trial designed to examine the effects of an 8-week CrossFit-based concurrent training program on both physical fitness and psychological well-being in school-aged children (boys and girls aged 7 to 11 years). The sample will be drawn from a primary school in Córdoba (Spain) and will be randomly assigned to either an experimental group (n=15) or a control group (n=15).
The experimental group will participate in a supervised CrossFit Kids program, consisting of two weekly sessions of 50 minutes each. These sessions will include functional, age-appropriate high-intensity exercises structured into four parts: warm-up (mobility and games), strength work (technical and developmental exercises), metabolic conditioning (METCON), and a final cool-down or game-based activity. The control group will continue with their usual daily routine without any structured physical training during the intervention period.
The study will assess changes in physical fitness variables, including muscular strength (countermovement jump, handgrip strength, standing long jump, and medicine ball throw), cardiorespiratory fitness (Course Navette test, burpees, abdominal endurance tests, and step tests), and body composition indicators such as BMI, waist circumference, and waist-to-height ratio. In addition, psychological outcomes will be evaluated using validated instruments measuring state and trait anxiety (State-Trait Anxiety Inventory), daily stress (Children's Daily Stress Inventory) and self-esteem (Rosenberg Self-Esteem Scale).
Measurements will be taken before and after the intervention to compare intra- and inter-group changes. The study also explores potential relationships between improvements in physical fitness and psychological outcomes.
The main hypothesis is that participation in the CrossFit-based concurrent training program will lead to significant improvements in strength, endurance, body composition, and psychological well-being (reduced anxiety and stress and improved self-esteem) compared to the control group, highlighting the potential of this training approach as an effective and comprehensive intervention for children.
Study design
- Primary purpose
- Other
- Allocation
- Non-randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- Randomized clinical trial
| Arm | Type | Receives |
|---|---|---|
| Crossfit training | Experimental | Other: CrossFit training |
| Control | No intervention | –The control arm will not receive any structured exercise intervention during the study period and will continue with their usual daily school routine. This will allow comparison of changes in physical and psychological outcomes between both groups. |
Who may qualify
- Ages
- 7 to 11 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child
Key inclusion criteria (8 listed)
- Age: 7-11 years.
- Students enrolled at CEIP Pablo García Baena (Córdoba).
- Availability to attend the Triple XXX Box (Polígono Pedroches, C. los Alfareros, Parcel 119, 14014 Córdoba), where both assessments and training sessions will be conducted.
- Availability to attend training sessions twice per week for the 8-week intervention period.
- No participation in extracurricular physical activity prior to the start of the CrossFit program.
Key exclusion criteria (3 listed)
- Children with musculoskeletal injuries, diseases, or medical, psychological, or behavioral conditions that limit physical activity or interfere with the assessment of outcomes.
- Inability or anticipated difficulty in regularly attending training sessions.
- Refusal of parents or legal guardians to provide informed consent.
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 |
|---|---|---|
| CrossFit trainingAlso: Body composition, Psychological OutcomesThe experimental arm will receive an 8-week concurrent training intervention based on a CrossFit program adapted for children, with a frequency of two 50-minute sessions per week. Each session will be structured into a warm-up (mobility exercises and games), strength training (technical and functional exercises), metabolic conditioning (METCON), and a cool-down phase. The program will be supervised by qualified professionals to ensure safety and proper execution of the exercises. | Other | Crossfit training |
Primary outcome
Countermovement Jump Test (CMJ) - Explosive Strength Test
Time frame: Week 1 (Day 1), Week 8 (Day 16)
The countermovement jump (CMJ), is used to assess explosive strength of the lower limbs. In this test, participants begin in an upright standing position with their hands placed on their hips to avoid arm swing contribution. They are instructed to perform a maximal vertical jump following a rapid downward countermovement, descending to approximately 90° of knee flexion, and then immediately jumping as high as possible.
Standing Long Jump
Time frame: Week 1 (Day 1), Week 8 (Day 16)
This test consists of performing a horizontal jump using both feet simultaneously, starting from the same level. A preliminary jump is not allowed. The maximum horizontal distance achieved is recorded, measuring from the starting line to the rearmost point of the shoe closest to that line. Upon landing, the participant must maintain balance and remain stationary.
Medicine Ball Throw Test
Time frame: Week 1 (Day 1), Week 8 (Day 16)
The medicine ball throw test (2 kg) is performed from an upright standing position, holding the ball with both hands above the head. Participants are required to throw the ball as far as possible by performing a flexion-extension movement of the legs, with or without trunk extension.
20 m Shuttle Run Test (Course-Navette)
Time frame: Week 1 (Day 1), Week 8 (Day 16)
In the 20 m shuttle run test, participants run back and forth between two lines set 20 m apart, with progressively increasing speed. The initial running speed is 8.5 km/h and increases by 0.5 km/h every minute. Each increase in speed corresponds to a new level.
Plank Hold Time
Time frame: Week 1 (Day 1), Week 8 (Day 16)
The plank protocol requires participants to maintain a static prone position, with only the forearms and toes in contact with the ground. Proper form requires feet together with toes pointing downward, elbows positioned under the shoulders at forearm width, and hands clasped together on the floor.
Burpess
Time frame: Week 1 (Day 1), Week 8 (Day 16)
To perform a burpee, participants begin with feet shoulder-width apart and lower into a squat by bending the knees. They then place their palms on the floor and jump back into a plank position with arms extended, ensuring hands face forward, feet rest on the toes, and the back remains straight. Next, they perform a push-up by bending the elbows and returning to the plank position. Then, they jump forward into a squat position, keeping hands on the ground, hips lowered, thighs parallel to the floor, and knees positioned between the elbows. Finally, they jump vertically from the squat position, extending the arms overhead during the jump.
Step Test
Time frame: Week 1 (Day 1), Week 8 (Day 16)
This test consists of stepping up and down on a platform approximately 30 cm in height, maintaining a constant speed and rhythm.
State-Trait Anxiety Inventory for Children
Time frame: Week 1 (Day 1), Week 8 (Day 16)
State-Trait Anxiety Inventory for Children is a psychological instrument designed to measure two dimensions of anxiety in children: state anxiety, referring to temporary or situational anxiety, and trait anxiety, which assesses the general tendency to experience anxiety.
Children's Daily Stress Inventory
Time frame: Week 1 (Day 1), Week 8 (Day 16)
This test aims to assess daily stress in children by evaluating how common experiences, such as school, family, and social issues, contribute to stress levels.
Rosenberg Self-Esteem Scale
Time frame: Week 1 (Day 1), Week 8 (Day 16)
The Rosenberg Self-Esteem Scale assesses an individual's self-worth through a series of statements reflecting overall self-evaluation.
2 secondary outcomes
Body composition
Time frame: Week 1 (Day 1), Week 8 (Day 16)
Perceived Exertion
Time frame: Week 1 (Day 1), Week 8 (Day 16)
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 30 Apr 2026.
- Derived from this study: PubMed 42506821Duran-Lopez N, Gomez-Garcia C, Ranchal-Sanchez A, Lucena-Jurado V, Moyano-Ortega V, Lara-Barahona Ostos A, Jurado-Castro JM. High-Intensity Functional Concurrent Training for Physical Fitness, Body Composition, and Psychological Outcomes in Schoolchildren: Protocol for a Randomized Controlled Trial. Sports (Basel). 2026 Jul 3;14(7):279. doi: 10.3390/sports14070279.
- 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.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing CrossFit training in people with Children and Crossfit, run by Maimónides Biomedical Research Institute of Córdoba at 1 site in Spain.
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: opening soon, as of the sponsor's last update on 30 Apr 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 Spain. 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?
Contact José Manuel Jurado Castro (+34 957 21 37 00, jose.jurado@imibic.org), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Countermovement Jump Test (CMJ) - Explosive Strength Test (time frame: Week 1 (Day 1), Week 8 (Day 16)). The study lists 10 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 NCT07552844, which also lists 1 linked publication.
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 30 Apr 2026.