A waist-to-height ratio of 0.50 marks declining physical performance in active adults

BACKGROUND: For physically demanding job standards, simple anthropometric screening tools are useful. Using military personnel as a model, this study evaluated waist-to-height ratio (WHtR) for its relationship with health and performance indicators. METHODS: Data were analyzed from 2153 active-duty U.S. Marines (1421 men; 732 women). Relationships were assessed between WHtR, a circumference-based "tape test" (TT), body mass index (BMI), and a criterion measure of dual-energy X-ray absorptiometry (DXA)-derived percent body fat (%BF). Associations between WHtR and physical readiness were evaluated using composite scores from the Physical and Combat Fitness Tests (PFT, CFT), and individual performance metrics (pull-ups, crunches, 880-yard sprint time, 3-mile run time, ammo can overhead lifts). RESULTS: WHtR was strongly correlated with DXA %BF (r = 0.754, p < 0.001, men; r = 0.677, p < 0.001, women) and moderately negatively with PFT (r = -0.33, p < 0.001) and CFT (r = -0.30, p < 0.001) scores for men. A graded decline in physical fitness scores was observed with increasing WHtR, with a clear inflection in performance outcomes occurring between WHtR values of approximately 0.48-0.50. Receiver Operating Characteristic (ROC) analysis to identify high %BF showed the TT (AUC: 0.889 men, 0.876 women) performed better than WHtR (AUC: 0.851 men, 0.848 women) and BMI. CONCLUSIONS: WHtR is a simple and effective screening tool to identify personnel at potential risk for poor performance outcomes. These findings support use of WHtR as a screening metric and a potential replacement for traditional height-weight screening tables, with a pragmatic threshold of 0.50 to identify individuals who may benefit from secondary assessment, such as from multi-frequency bioelectrical impedance analysis.