Reliability and Construct Validity of the Persian Version of the ALPHA-Fitness Test Battery in Iranian Children

Introduction: School-based physical fitness (PF) assessments are widely used to monitor health-related fitness in children. However, evidence regarding the measurement properties of internationally recognized fitness batteries remains limited in some cultural contexts, including Iran.
Objective: To evaluate the reliability and construct validity of the Iranian adaptation of the ALPHA-Fitness Test Battery among Iranian children.
Methods: A methodological study was conducted with 458 Iranian schoolchildren (241 boys, 217 girls; mean age=10.45 years). Participants completed the Iranian adaptation of the ALPHA-Fitness Test Battery. Test–retest reliability was evaluated over a 7-day interval using ICC, SEM, MDC95, CV, and Bland–Altman analyses. Construct validity was assessed through EFA and CFA, while measurement invariance across sex was examined using multi-group CFA.
Results: All fitness tests demonstrated good-to-excellent reliability (ICC=0.84–0.95), with low measurement error and acceptable agreement between testing sessions. EFA identified a three-factor structure representing muscular fitness, functional/cardiorespiratory fitness, and flexibility, explaining 71.8% of the total variance. CFA supported the proposed model (χ²/df=2.14, CFI=0.96, TLI=0.95, RMSEA=0.051, SRMR=0.043). Multi-group CFA confirmed configural, metric, and scalar invariance across sex.
Conclusion: The Iranian adaptation of the ALPHA-Fitness Test Battery demonstrated satisfactory reliability and strong construct validity, supporting its use for school-based assessment of PF in Iranian children.