Long-Term Impact of Physical Activity Levels After High-Speed Resistance Training on Cardiac Autonomic Control in Independent Older Adults.

This study investigated the influence of physical activity (PA) levels on the long-term retention of the effects on cardiac autonomic control, assessed by heart rate variability (HRV), following a 16-week high-speed resistance training (HSRT) program over a 12-month follow-up period. At 12-month follow-up period, 36 participants who completed the measurements were categorized into light activity group (LAG) and moderate-to-vigorous activity group (MVAG) based on their PA levels. HRV data were recorded over a 6-min period. Significant within-group differences were observed over time. In MVAG, systolic blood pressure was significantly lower at the 6-month follow-up compared to pre-intervention (  = -0.87), while in LAG, diastolic blood pressure was lower at the 12-month follow-up compared to post-intervention (  = -0.66). Additionally, MVAG demonstrated significantly higher mean RR values at the 12-month compared to the 6-month follow-up (  = 0.49). Moreover, minimum and mean heart rate values were significantly higher at the 6-month compared to the 12-month follow-up (  = -0.39 and  = -0.42, respectively) in MVAG. Lastly, Sample Entropy was significantly higher in LAG compared to MVAG at 12-month follow-up (  = -0.89). In conclusion, participants who maintained moderate-to-vigorous PA during the 12-month follow-up demonstrated better retention of parasympathetic-related indices effects, as well as overall autonomic nervous system markers.