We used the mixed-models analysis main effect for age to examine the effects of age on physiologic variables, across all treatment conditions. With age treated, respectively, as a dichotomous (> 40 years or < 40 years) and continuous variable, values among older subjects were lower than among younger subjects, thus indicating poorer cardiovascular regulation, for LF HRV (p < 0.002, p < 0.0001), high-frequency (HF) HRV (p < 0.002, p < 0.0001), SD of normal R-R intervals (p = not significant [NS], p < 0.011), coefficient of variation in R-R intervals (p = NS, p < 0.0085), and cross-spectral α LF baroreflex gain (p < 0.0001, p < 0.0001). Values were higher for forced oscillation measures, indicating poorer pulmonary function, for frequency dependence (p < 0.006, p < 0.009) and resonant frequency of the lung (p < 0.01, p = NS). With the exception of resonant frequency, the significance of differences was greater when examining age as a continuous variable than as a dichotomous variable, indicating that age continues to affect these physiologic variables past age 40 years. There were no age differences in forced oscillation resistance at 6 Hz.