NCT07310251

Brief Summary

Considering the importance of an optimal warm-up to enhance performance in key soccer-related variables such as jump height, sprint speed, and ball kicking velocity, most available evidence to date has focused on youth and adult players, with limited studies conducted in children. Therefore, this study aimed to assess and compare the effects of a conventional warm-up and warm-ups including static stretching condition (SSC), dynamic stretching condition (DSC), and ball-specific condition (BSC) on jump performance countermovement jump (CMJ), squat jump (SJ), and drop jump (DJ) as well as on curve sprint speed, the Illinois change of direction test (ICODT), and ball kicking speed in male child soccer players. We hypothesized that the dynamic stretching warm-up would produce superior performance across most variables compared with the other conditions, due to its potential benefits for neuromuscular activation and optimization of the stretch shortening cycle.

Trial Health

63
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Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
20

participants targeted

Target at below P25 for not_applicable

Timeline
4mo left

Started Feb 2026

Shorter than P25 for not_applicable

Geographic Reach
1 country

1 active site

Status
not yet recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

Study Progress41%
Feb 2026Aug 2026

First Submitted

Initial submission to the registry

December 1, 2025

Completed
29 days until next milestone

First Posted

Study publicly available on registry

December 30, 2025

Completed
2 months until next milestone

Study Start

First participant enrolled

February 26, 2026

Completed
3 months until next milestone

Primary Completion

Last participant's last visit for primary outcome

May 18, 2026

Expected
3 months until next milestone

Study Completion

Last participant's last visit for all outcomes

August 20, 2026

Last Updated

December 30, 2025

Status Verified

December 1, 2025

Enrollment Period

3 months

First QC Date

December 1, 2025

Last Update Submit

December 15, 2025

Conditions

Keywords

Childsoccersportsplayers

Outcome Measures

Primary Outcomes (6)

  • Bipedal height

    Bipedal height was measured using the Frankfort plane in a horizontal position, with a tape measure (Bodymeter 206, SECA, Germany; accuracy to 0.1 cm) attached to the wall

    8 Weeks

  • Body mass

    Body mass was measured using an electronic scale (Omron HBF 514, Osaka, Japón; accuracy to 0.1 kg), while BMI was calculated by dividing body mass by bipedal height squared (kg/m2).

    8 weeks

  • Jump performance

    All jump tests were performed according to previous recommendations. For the CMJ, soccer players performed maximum effort jumps on an Ergojump® Globus mobile contact platform (ErgoTest, Codogne, Italy) with their arms resting on their iliac crests. Takeoff and landing were standardized at the exact location, and players performed full knee and ankle extensions during the flight phase. For the SJ, players stepped onto the contact platform with their arms on the iliac crest and knees semi-flexed at a 90° angle and the "stop" signal; the player maintained this posterior position, performing the maximum jump. Takeoff and landing were standardized at the exact location, and players performed full knee and ankle extensions during the flight phase. In the DJ test, participants were instructed to minimize ground contact time (\<250 ms) after stepping off a 20 cm box. The best of three jumps (with a 1-

    8 weeks

  • Curve sprint speed

    Sprint time was assessed to the nearest 0.01s using single-beam timing gates Brower® Timing System, (Salt Lake City, Utah, United States of America). The test consisted of placing a "semicircle" at a distance of 17 m outside the large area of the soccer field, which is standardized as follows: a radius of 9.15 m from the penalty spot, a distance of 14.6 m from the starting point to the end in a straight line, an angle of 105.84° measured from the penalty spot, and a total distance of 17 m (determined by trigonometric analysis). Photocells were installed at both ends of the semicircle to determine the time it took the players to run the curve. The test started from the left side, and the participant had to run at maximum speed until crossing the finish line. Two attempts were evaluated in both directions of the curve (left and right), recording the results as "dominant side" and "non-dominant side," depending on the dominance of the children soccer player's lower

    8 weeks

  • Agility

    The dimensions and route markings for the Illinois Change of Direction Test (ICODT) were adjusted to established methods. The ICODT consists of placing four markers to indicate an area of 10 m by 5 m. In the center of the area, four markers are placed at 3.3 m from each other. The children soccer players start in a prone position with their chin touching the surface of the starting line. They accelerate for 10 m, turn around, return to the starting line, zigzag in and out of the four markers, and finally complete a second 10 m sprint to finish the ICODT speed test. Players were instructed to run around the markers rather than cross them. If a participant did not follow these instructions, the test was terminated and restarted after a 3-minute recovery period. Performance results were collected using Brower® Timing System single-beam timing gates (Salt Lake City, Utah, United States of America).

    8 weeks

  • Ball kicking speed

    Participants performed a maximal instep ball strike with their dominant and non-dominant legs after a two-stride run using a size five soccer ball (Molten Vantaggio 5000®, FIFA PRO certified, Hiroshima). Maximum speed was measured with a radar gun Speed (Gun SR3600, Sports Radar®, Homosassa, Florida, United States of America). Three attempts were carried out, recording the best of the three with a 1-min rest between each attempt. The data obtained for ball kicking speed was determined to have high reliability of 0.92.

    8 weeks

Study Arms (4)

Conventional warm-up condition

EXPERIMENTAL

The CC performed a traditional soccer warm-up for 10 minutes, consisting of 4 minutes of jogging in different directions at moderate to vigorous intensities, measured using the 10-point perceived exertion scale (RPE) scale, starting between 3 and 5 points and ending between 6 and 8 points, followed by movements performed in matches (jumps, ball kicks, changes of direction) distributed in three sets of 60 seconds each with a 60-second rest between sets. This condition did not include flexibility exercises.

Other: conventional warm-up regarding to stretching warm-up

Static stretching condition

EXPERIMENTAL

The SSC consisted of a warm-up with static stretching for 10 minutes. Four stretching exercises were performed, one for each lower body muscle group (quadriceps, glutes, hamstrings, and triceps sural), distributed in two sets of 30 seconds each with a 45-second rest per exercise, performing progressive increases in joint range of motion. The intensity started between 3 and 5 points, ending between 6 and 8 points on the RPE scale

Other: conventional warm-up regarding to stretching warm-up

Dynamic stretching condition

EXPERIMENTAL

The DSC consisted of a 10-min warm-up with dynamic stretching. Four stretching exercises were performed, one for each lower body muscle group (quadriceps, gluteus, hamstrings and triceps surae) distributed in two series of 30 s each with a rest of 45 s per exercise, dynamically executing oscillatory stretching movements with progressive increases in speed. The intensity started between 3 and 5 points, ending between 6 and 8 points of RPE.

Other: conventional warm-up regarding to stretching warm-up

Ballistic stretching condition

EXPERIMENTAL

The BSC consisted of a warm-up with ballistic stretching for 10 min. Four stretching exercises were performed, one for each muscle group of the lower body (quadriceps, gluteus, hamstrings and triceps surae) distributed in two series of 30 s each with a rest of 45 s per exercise in which an elongated position was maintained for 5 s then 5 s of oscillation with progressive increments until completing the 30 s of each series. The intensity started between 3 and 5 points, ending between 6 and 8 points of RPE.

Other: conventional warm-up regarding to stretching warm-up

Interventions

The warm-up protocol was based on the guidelines of a previous study conducted on adolescent players in Chile. The CC performed a traditional soccer warm-up for 10 minutes, consisting of 4 minutes of jogging in different directions at moderate to vigorous intensities, measured using the 10-point perceived exertion scale (RPE) scale, starting between 3 and 5 points and ending between 6 and 8 points, followed by movements performed in matches (jumps, ball kicks, changes of direction) distributed in three sets of 60 seconds each with a 60-second rest between sets. This condition did not include flexibility exercises. The SSC consisted of a warm-up with static stretching for 10 minutes. Four stretching exercises were performed, one for each lower body muscle group (quadriceps, glutes, hamstrings, and triceps surae), distributed in two sets of 30 seconds each with a 45-second rest per exercise, performing progressive increases in joint range of

Also known as: usual care
Ballistic stretching conditionConventional warm-up conditionDynamic stretching conditionStatic stretching condition

Eligibility Criteria

Age8 Years - 13 Years
Sexmale
Healthy VolunteersYes
Age GroupsChild (0-17)

You may qualify if:

  • Male children aged 8 - 13 years, enrolled in a soccer school affiliated with amateur clubs in Chile.
  • Regular participation in organized soccer training (≥2 sessions per week) for at least six months prior to the study.
  • Absence of musculoskeletal or neurological injuries that could limit the ability to perform the warm-up or physical performance assessments.
  • Availability of appropriate sports clothing and footwear for testing sessions.
  • No concurrent participation in other soccer schools or competitive teams during the study period.
  • No official matches or competitions scheduled on the same days as the experimental sessions.
  • Signed assent and informed consent provided by the participant and a parent or legal guardian, respectively.

You may not qualify if:

  • Sustain an injury or illness during the study period that prevents participation in testing.
  • Fail to complete all four experimental conditions or physical assessments.
  • Demonstrate non-compliance with the warm-up instructions or assessment procedures.

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Universidad Católica del Maule

Talca, Talca, 3465548, Chile

Location

Central Study Contacts

Pablo Valdes-Badilla, Doctor

CONTACT

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
QUADRUPLE
Who Masked
PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
Purpose
TREATMENT
Intervention Model
CROSSOVER
Model Details: This randomized crossover trial will investigate the acute effects of four different warm-up protocols on physical performance in male child soccer players
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
PhD. in Physical activities science

Study Record Dates

First Submitted

December 1, 2025

First Posted

December 30, 2025

Study Start

February 26, 2026

Primary Completion (Estimated)

May 18, 2026

Study Completion (Estimated)

August 20, 2026

Last Updated

December 30, 2025

Record last verified: 2025-12

Locations