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

The aim of this study was to examine the associations of body composition, physical performance, and inflammatory/oxidative stress biomarkers with aerobic capacity, indexed by peak oxygen uptake, 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 peak oxygen uptake, 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 indicated no problematic multicollinearity. The baseline linear model explained moderate variance in peak oxygen uptake, and adding estimated pulse wave velocity and high-density lipoprotein (HDL) cholesterol modestly improved fit. Fat mass remained a strong negative predictor, while HDL cholesterol showed an independent positive association with the peak oxygen uptake. 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 peak oxygen uptake. Modeling nonlinear relationships improved prediction, suggesting that adiposity, estimated arterial stiffness, and metabolic health jointly contribute to aerobic capacity beyond age in occupational personnel.