Metabolic and Arterial Stiffness Correlates of Aerobic Capacity in Male Occupational Personnel

To examine associations between body composition, physical performance, and inflammatory/oxidative stress biomarkers with aerobic capacity, indexed by VO₂peak, among tactical personnel, and to develop predictive models for health, performance, and readiness assessment. Complete case data were available for 102 occupational personnel. Variance inflation factors assessed multicollinearity. Linear models tested associations with VO₂peak, while generalized additive models explored nonlinear relationships. A 10-fold cross-validation procedure evaluated model performance, and diagnostic and sensitivity analyses assessed robustness. Variance Inflation Factors (VIFs) indicated no problematic multicollinearity. The baseline linear model explained moderate variance in VO₂peak, and adding estimated pulse wave velocity and HDL cholesterol modestly improved fit. Fat mass remained a strong negative predictor, while HDL cholesterol showed an independent positive association with VO₂peak. The generalized additive model provided better fit and identified nonlinear relationships for fat mass and estimated pulse wave velocity. Cross-validation also supported better predictive performance for the generalized additive model than the linear model. Overall, higher fat mass and estimated arterial stiffness were associated with lower aerobic capacity, whereas HDL cholesterol was positively associated with VO₂peak. Modeling nonlinear relationships improved prediction, suggesting that adiposity, estimated arterial stiffness, and metabolic health jointly contribute to aerobic capacity beyond age in occupational personnel.