Exploring Acceptability, Feasibility, and Impact of Heart Rate Variability to Provide Physical Activity Guidance Postpartum

ABSTRACT Introduction Women report lower levels of physical activity (PA) postpartum due to numerous barriers to engagement such as lack of time, energy, motivation, social support, and fatigue. Despite these noted barriers, PA recommendations are universal and do not allow for a tailored PA approach. Therefore, we assessed the acceptability, feasibility, and impact of individualized postpartum PA guidance. Method Participants measured heart rate variability (HRV) for 3 min every morning for 2 wk. These baseline measures were used to create individualized HRV-guided PA recommendations. The goal was to create HRV-based zones with appropriate options for PA. Participants were instructed to measure and record their HRV daily for the 8-wk intervention period and choose a daily activity that was appropriate to their reading. A mixed-methods approach of pre- and post-intervention questionnaires and qualitative interviews were used to assess the impact of the intervention on participants and whether they felt the intervention was acceptable and feasible. Results The average age of women in the study was 33 (3.7) yr, and participants were, on average, 29 (7.4) wk (7.2 (1.9) months) postpartum. Participants reported recording their daily HRV on an average of 49 of the 56 d (88%) comprising the 8-wk intervention period. Participants reported completing, on average, 27 sessions (48%) in the correct categories (i.e., the zone indicated by the daily HRV reading). From baseline to post-intervention, there were significant improvements in PA, fatigue, and sleep. Participants noted high acceptability but low feasibility of the HRV method for individualized PA guidance. Conclusions Although a relatively simple intervention (i.e., daily HRV readings) may enhance PA and other outcomes, this intervention was only somewhat feasible and left women desiring greater support and accountability.