Introduction. Hansen et al. (1) formerly showed a positive relationship between baseline vagally mediated Heart Rate Variability (HRV) and Executive Function (EF) in a sample of soldiers. Later studies have found similar results among young and older adults (2) and patients with panic disorder (3). At the same time, HRV have been related to older adults’ functional fitness (FF) (4). Therefore, our purpose was to evaluate whether resting HRV was related to EF and FF among older women.Methods. This study is a cross-sectional analysis of 103 older women (73±6 yrs) participating in a longitudinal functional training intervention. The Stroop Colour-Word test was employed to assess cognitive functioning. Performance was quantified by number of items completed in 45 s and colour-word task score (STR-C) served as measure of EF. FF was evaluated using the chair-stand test (CST), timed Up&Go test (TUGT) and handgrip strength (GRIP). Resting HRV was recorded (Polar RS800CX) in a lying position during 10 min and subsequently treated using KUBIOS HRV 2.0 software. The standard deviation of RR intervals (SDNN), root-mean square difference of successive RR intervals (RMSSD), low-frequency spectral power (LF), high-frequency spectral power (HF) LF/HF ratio and the short-term scaling exponent (DFA1) were retained for further analysis. After testing for normality (Shapiro-Wilks), all the HRV variables except from DFA1 were log transformed (ln). A partial correlation controlling for age, RRi, and total spectral power was used to assess possible relationships.Results from the correlational analysis are displayed in Table 1.Conclusions. Our outcomes coincide with previous studies in showing a relationship between HRV and both EF (1-3) and FF (4). However, unlike those earlier investigations, among our participants higher linear HRV (i.e., lnSDNN and lnRMSSD) was associated to a worse EF and FF. On the contrary, DFA1 was positively correlated to EF and FF. Overall, our study reinforce Stein et al. (5) suggestion that higher HRV is not always better HRV and nonlinear analysis (DFA1) are more suitable when assessing older adults. Nevertheless, the cross-sectional design of our study prevents us from concluding that the above shown relationship means that HRV and EF change in concert. Hence, further longitudinal studies are warranted to deepen into this association.