(A) Salivary cortisol concentrations (nmol/L) measured at different sampling times during the day in high-fit (HF, n = 10) and low-fit (LF, n = 12) subjects. WSANOVA revealed a significant main group effect of aerobic fitness for cortisol levels overall [F(1,21) = 8.80, p < .05, Cohen’s d = -.54], as indicated by †. The effect was confirmed by ANCOVA testing, controlling for age and BMI as covariates [F(1,21) = 3.76, p < .05, Cohen’s d = -.54]. Significant group x time interaction (t-test; p < .05) is indicated by *. (B) The area under the curve values with respect to ground (AUC) for total cortisol output are lower in the HF participants (77.24±17.86 vs. 131.59±16.85 in HF and LF, respectively; t-test, p = .02). ANCOVA testing, adjusting for age and BMI, confirmed the effect [F(1,21) = 5.57, p < .05, Cohen’s d = -1.19]. In both (A) and (B), data are reported as mean values ± SEM. *, p < .05.