Associations Between Sedentary Behavior And Steps With Heart Rate Variability In Desk Workers

Abstract

PURPOSE: More sedentary behavior (SB) has been associated with reduced heart rate variability (HRV) in blue-collar workers; however, this association has not yet been examined in desk workers who engage in high levels of SB. This study explored associations between SB and steps/day with HRV in desk workers. METHODS: This analysis of baseline data of a subsample of participants from an ongoing clinical trial included thirty-three insufficiently active adults (age: 43.7 ± 11.6 yr; BMI: 30.0 ± 6.3 kg/m2) with desk jobs and elevated blood pressure. An activPAL3 micro device was placed on the anterior midpoint of the thigh for one week to measure SB and steps. Total and prolonged (≥30 continuous minutes) SB and total steps/day were averaged across valid days for participants with ≥10 hr/day on ≥4 days. For HRV, beat-to-beat intervals were collected during a 10-min supine rest using a Polar V800 monitor, with the last 5 min analyzed using Kubios software to measure parasympathetic-related HRV parameters including: mean R-R intervals, root mean square of successive differences (RMSSD), standard deviation of normal R-R intervals (SDNN) and high frequency (HF). Natural-log (ln) transformation was applied for skewed HRV variables. Simple and partial Pearson’s correlations between SB, steps/day and HRV parameters were calculated before and after controlling for age. RESULTS: Correlations were not statistically significant between total or prolonged SB with any of the HRV parameters (Table 1.). Steps/day were correlated with mean R-R intervals (r = .371; p = .034), with the correlation attenuated when controlling for age (r = .320; p = .075). No other significant correlations were detected between steps/day and other HRV parameters. CONCLUSION: While SB was not correlated to HRV, more steps/day were related to greater parasympathetic-related HRV in adults with desk jobs. These results may suggest that movement rather than SB should be the focus of approaches to enhance HRV.