Effects of an ACWR-Guided Load Management Intervention on Time-Loss Injury Incidence in Chinese Elite Youth Footballers: A Cluster Randomised Controlled Trial
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: ACWR-guided load management.
- Who it may be relevant to
- Registry conditions: Time-Loss Injury Incidence. Basic parameters: 13 years — 19 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- Center list to be confirmed — check the primary protocol.
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Overview
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.
Interventions
- Behavioral ACWR-guided load management
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 R
Primary outcome measures
- Time-loss injury incidence rate per 1000 athlete-exposure hours. [Time frame: From enrolment to the end of the 10-month competitive season]
Eligibility criteria
Inclusion criteria
- 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)
Exclusion criteria
- Injury precluding full participation at enrolment Failure to provide informed consent Age outside 13-19 years
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: Yes
Study design
- Allocation
- N/A
- Model
- Single group
- Masking
- Open label
- Primary purpose
- Prevention
Study locations
Center list to be confirmed — check the primary protocol.
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. PMID 31452129
Identifiers
NCT: NCT07727382 · XYAFUAE2026021