Time-Loss Injury IncidenceACWR InjuryNCT07727382
Effects of an ACWR-Guided Load Management Intervention on Time-Loss Injury Incidence in Chinese Elite Youth Footballers: A Cluster Randomised Controlled Trial
A study testing ACWR-guided load management in people with Time-Loss Injury Incidence, run by Xinyang Agriculture and Forestry University.
Trial summary
This cluster-randomised controlled trial aims to evaluate whether a multi-component load management intervention-incorporating real-time acute:chronic workload ratio (ACWR) feedback, automated alerts, coach education, and structured load adjustment protocols-reduces time-loss injury incidence in Chinese elite… Read more about this study
- Who is it for?
- Ages 13 to 19 yearsHealthy volunteers can take part
- Conditions the study is for
- Time-Loss Injury Incidence
- What is being tested?
- ACWR-guided load management
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 847 participants
- Where
- No sites listed yet
- Study dates
- 1 Jul 2026to 30 Apr 2027
- 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 13 to 19 years
- All sexes
- Healthy volunteers accepted
- Child, Adult
Who may be able to join
- Age 13-19 years Member of a participating U15, U17, or U19 team No injury precluding full participation at enrolment Provided written informed consent (parental consent for minors)
Who cannot join
- Injury precluding full participation at enrolment Failure to provide informed consent Age outside 13-19 years
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
About this study
This cluster-randomised controlled trial aims to evaluate whether a multi-component load management intervention-incorporating real-time acute:chronic workload ratio (ACWR) feedback, automated alerts, coach education, and structured load adjustment protocols-reduces time-loss injury incidence in Chinese elite mixed-gender adolescent football players compared with routine training practices.
Read the detailed description
Background: Injury prevention in elite youth football is a public health and performance priority. Approximately two-thirds of players sustain at least one time-loss injury annually, with lower extremity injuries predominating. The acute:chronic workload ratio (ACWR) is widely used in sport science as a practical decision-support tool, yet experimental evidence for its effectiveness in reducing injury incidence remains limited and conflicting, particularly in Asian adolescent populations.
Objectives: This cluster-randomised controlled trial evaluates whether a multi-component ACWR-guided load management intervention reduces time-loss injury incidence in Chinese elite youth football players compared with routine practice.
Study Design: A prospective, two-arm, parallel-group, cluster-randomised controlled trial with 1:1 allocation, stratified by age group (U15/U17/U19).
Participants: Twenty-eight elite youth football teams (U15-U19, n=774, 45.2% female) from 28 academies in Henan Province.
Intervention: The intervention comprises real-time ACWR feedback, automated alerts for values outside the 0.8-1.3 range, coach education workshops, and structured load-adjustment protocols. Control teams follow routine practice without ACWR-derived feedback.
Primary Outcome: Time-loss injury incidence rate per 1000 athlete-exposure hours.
Secondary Outcomes: (1) Severe injury incidence (≥28 days lost); (2) Injury burden (days lost per 1000 h); (3) Proportion of lower-extremity injuries; (4) Proportion of non-contact injuries.
Sample Size: 28 teams (14 per arm) with 774 players (median 27 per team, range 22-31), providing 80% power to detect a 25% reduction in injury incidence (IRR=0.75) with α=0.05 and ICC=0.05.
Statistical Analysis: Mixed-effects Poisson regression with ICC adjustment, Fine-Gray competing risk models, shared frailty Cox models, Kaplan-Meier survival analysis, and E-value sensitivity analysis.
Ethics: The study protocol was approved by the Xinyang Agriculture and Forestry University Ethics Committee (XYAFUAE2024021). Written informed consent was obtained from all participants and their parents/legal guardians.
- Conditions
- Time-Loss Injury Incidence
- Being tested
- ACWR-guided load management
- Keywords
- acute: chronic workload ratio(ACWR), training load management, injury prevention, soccer, adolescent athletes
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
ACWR-guided load managementBehavioural
Intervention teams implement a structured ACWR-guided load management protocol for the entire season. The protocol comprises four components:
Component 1 - Load Monitoring: After each training session and match, players rate perceived exertion on the Borg CR-10 scale. Session-RPE (sRPE) is calculated as duration (minutes) × RPE score. Data are recorded using a dedicated mobile application (CoachMe v3.2). Research staff provide technical support and weekly reminders.
Component 2 - Weekly ACWR Reports: The research team generates weekly ACWR reports for each player. Reports are emailed to head coaches each Monday morning, covering the preceding week's data.
Component 3-Automated Alerts and Load-Adjustment Recommendations: Coaches receive automated alerts when a player's ACWR falls below 0.8 or exceeds 1.3. When ACWR < 0.8, a progressive increase in training load (10-20% weekly) is suggested. When ACWR > 1.3, coaches are instructed to implement a 10-20% load reduction at the next session,
| Study group | Role | What they receive |
|---|---|---|
| ACWR Intervention vs Control Trial | Active comparator | Coaches in this group will plan and adjust all training sessions based on published Acute:Chronic Workload Ratio (ACWR) load management principles. Player training load data will be monitored using a commercially available athlete management system. The intervention will be implemented for the duration of the complete season. The ACWR will be used to guide training prescription, with the goal of managing the players' acute and chronic workloads to reduce injury risk Receives: Behavioral: ACWR-guided load management |
What is being measured
The primary outcome is the main question the study is designed to answer.
Time-loss injury incidence rate per 1000 athlete-exposure hours.
Definition: Consistent with the football injury consensus statement, a time-loss injury is defined as any physical impairment sustained during structured football training or competitive matches that prevents a player from full participation in subsequent training sessions or matches. Injuries occurring outside football activities are not recorded.
Measured: From enrolment to the end of the 10-month competitive season
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted27 Jul 2026
- Study start1 Jul 2026 (estimated)
- Primary completion30 Apr 2027 (estimated)
- Study completion30 Apr 2027 (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 Time-Loss Injury IncidenceStudies 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
- Prevention
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 847 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Xinyang Agriculture and Forestry University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Jun Li, Xinyang Agriculture and Forestry University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07727382
- Sponsor's protocol ID
- XYAFUAE2026021
- Acronym
- ACWR Injury
- Status last verified
- Jul 2026
- First submitted
- 20 Jul 2026
- Last updated
- 27 Jul 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: All of the individual participant data collected during the trial, after deidentification. This will include, but is not limited to: baseline demographic and anthropometric data, training load metrics (e.g., acute:chronic workload ratio \[ACWR\] and its components), time-loss injury incidence and severity data, and exposure hours. Additional documents to be made available: Study Protocol, Statistical Analysis Plan (SAP), and Informed Consent Form (ICF). Time frame: Data will be available beginning 9 months and ending 36 months following publication of the primary results. Access criteria: Data will be made available to researchers who provide a methodologically sound proposal for the purpose of achieving the aims in the approved proposal. Proposals should be directed to the Principal Investigator. To gain access, data requesters will need to sign a data access agreement
Publications
Jones S, Almousa S, Gibb A, Allamby N, Mullen R, Andersen TE, Williams M. Injury Incidence, Prevalence and Severity in High-Level Male Youth Football: A Systematic Review. Sports Med. 2019 Dec;49(12):1879-1899. doi: 10.1007/s40279-019-01169-8.
PubMed 31452129
Study at a glance
From the registry record, last updated by the sponsor on 27 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of an ACWR-Guided Load Management Intervention on Time-Loss Injury Incidence in Chinese Elite Youth Footballers: A Cluster Randomised Controlled Trial
- ClinicalTrials.gov ID
- NCT07727382
- Acronym / sponsor ID
- ACWR Injury / XYAFUAE2026021
- Conditions
- Time-Loss Injury Incidence
- Keywords
- acute: chronic workload ratio(ACWR), training load management, injury prevention, soccer, adolescent athletes
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 847 participants (estimated)
- Lead sponsor
- Xinyang Agriculture and Forestry UniversityUniversity, hospital or other
- Study start
- 1 Jul 2026 (estimated)
- Primary completion
- 30 Apr 2027 (estimated)
- Study completion
- 30 Apr 2027 (estimated)
- First posted
- 27 Jul 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 cluster-randomised controlled trial aims to evaluate whether a multi-component load management intervention-incorporating real-time acute:chronic workload ratio (ACWR) feedback, automated alerts, coach education, and structured load adjustment protocols-reduces time-loss injury incidence in Chinese elite mixed-gender adolescent football players compared with routine training practices.
Detailed description
Background: Injury prevention in elite youth football is a public health and performance priority. Approximately two-thirds of players sustain at least one time-loss injury annually, with lower extremity injuries predominating. The acute:chronic workload ratio (ACWR) is widely used in sport science as a practical decision-support tool, yet experimental evidence for its effectiveness in reducing injury incidence remains limited and conflicting, particularly in Asian adolescent populations.
Objectives: This cluster-randomised controlled trial evaluates whether a multi-component ACWR-guided load management intervention reduces time-loss injury incidence in Chinese elite youth football players compared with routine practice.
Study Design: A prospective, two-arm, parallel-group, cluster-randomised controlled trial with 1:1 allocation, stratified by age group (U15/U17/U19).
Participants: Twenty-eight elite youth football teams (U15-U19, n=774, 45.2% female) from 28 academies in Henan Province.
Intervention: The intervention comprises real-time ACWR feedback, automated alerts for values outside the 0.8-1.3 range, coach education workshops, and structured load-adjustment protocols. Control teams follow routine practice without ACWR-derived feedback.
Primary Outcome: Time-loss injury incidence rate per 1000 athlete-exposure hours.
Secondary Outcomes: (1) Severe injury incidence (≥28 days lost); (2) Injury burden (days lost per 1000 h); (3) Proportion of lower-extremity injuries; (4) Proportion of non-contact injuries.
Sample Size: 28 teams (14 per arm) with 774 players (median 27 per team, range 22-31), providing 80% power to detect a 25% reduction in injury incidence (IRR=0.75) with α=0.05 and ICC=0.05.
Statistical Analysis: Mixed-effects Poisson regression with ICC adjustment, Fine-Gray competing risk models, shared frailty Cox models, Kaplan-Meier survival analysis, and E-value sensitivity analysis.
Ethics: The study protocol was approved by the Xinyang Agriculture and Forestry University Ethics Committee (XYAFUAE2024021). Written informed consent was obtained from all participants and their parents/legal guardians.
Study design
- Primary purpose
- Prevention
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| ACWR Intervention vs Control Trial | Active comparator | Behavioral: ACWR-guided load managementCoaches in this group will plan and adjust all training sessions based on published Acute:Chronic Workload Ratio (ACWR) load management principles. Player training load data will be monitored using a commercially available athlete management system. The intervention will be implemented for the duration of the complete season. The ACWR will be used to guide training prescription, with the goal of managing the players' acute and chronic workloads to reduce injury risk |
Who may qualify
- Ages
- 13 to 19 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult
Key inclusion criteria (1 listed)
- Age 13-19 years Member of a participating U15, U17, or U19 team No injury precluding full participation at enrolment Provided written informed consent (parental consent for minors)
Key exclusion criteria (1 listed)
- Injury precluding full participation at enrolment Failure to provide informed consent Age outside 13-19 years
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 |
|---|---|---|
| ACWR-guided load managementIntervention teams implement a structured ACWR-guided load management protocol for the entire season. The protocol comprises four components: Component 1 - Load Monitoring: After each training session and match, players rate perceived exertion on the Borg CR-10 scale. Session-RPE (sRPE) is calculated as duration (minutes) × RPE score. Data are recorded using a dedicated mobile application (CoachMe v3.2). Research staff provide technical support and weekly reminders. Component 2 - Weekly ACWR Reports: The research team generates weekly ACWR reports for each player. Reports are emailed to head coaches each Monday morning, covering the preceding week's data. Component 3-Automated Alerts and Load-Adjustment Recommendations: Coaches receive automated alerts when a player's ACWR falls below 0.8 or exceeds 1.3. When ACWR < 0.8, a progressive increase in training load (10-20% weekly) is suggested. When ACWR > 1.3, coaches are instructed to implement a 10-20% load reduction at the next session, | Behavioural | ACWR Intervention vs Control Trial |
Primary outcome
Time-loss injury incidence rate per 1000 athlete-exposure hours.
Time frame: From enrolment to the end of the 10-month competitive season
Definition: Consistent with the football injury consensus statement, a time-loss injury is defined as any physical impairment sustained during structured football training or competitive matches that prevents a player from full participation in subsequent training sessions or matches. Injuries occurring outside football activities are not recorded.
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 27 Jul 2026.
- Results publication: PubMed 31452129Jones S, Almousa S, Gibb A, Allamby N, Mullen R, Andersen TE, Williams M. Injury Incidence, Prevalence and Severity in High-Level Male Youth Football: A Systematic Review. Sports Med. 2019 Dec;49(12):1879-1899. doi: 10.1007/s40279-019-01169-8.
- Individual participant dataSharing planned: Yes. All of the individual participant data collected during the trial, after deidentification. This will include, but is not limited to: baseline demographic and anthropometric data, training load metrics (e.g., acute:chronic workload ratio [ACWR] and its components), time-loss injury incidence and severity data, and exposure hours. Additional documents to be made available: Study Protocol, Statistical Analysis Plan (SAP), and Informed Consent Form (ICF). Time frame: Data will be available beginning 9 months and ending 36 months following publication of the primary results. Access criteria: Data will be made available to researchers who provide a methodologically sound proposal for the purpose of achieving the aims in the approved proposal. Proposals should be directed to the Principal Investigator. To gain access, data requesters will need to sign a data access agreement
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.
Questions about this trial
What is this clinical trial studying?
A study testing ACWR-guided load management in people with Time-Loss Injury Incidence, run by Xinyang Agriculture and Forestry University.
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: opening soon, as of the sponsor's last update on 27 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
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 Jun Li (13526075609, 2005210010@xyafu.edu.cn), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Time-loss injury incidence rate per 1000 athlete-exposure hours. (time frame: From enrolment to the end of the 10-month competitive season). 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 NCT07727382, 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 27 Jul 2026.