To assess the impact of a 16-week, supervised exercise training intervention on Heart Rate Variability (HRV) during sleep in individuals with Parkinson’s Disease (PD), compared to a sleep hygiene (SH) control.

HRV analysis serves as a non-invasive tool to monitor the balance between the sympathetic and parasympathetic arms of the autonomic nervous system. Prior studies have reported nocturnal autonomic imbalance in PD with significantly reduced sympathetic influence. In individuals with PD, exercise improves subjective and objective sleep, motor symptoms, and quality of life. However, little is known about the impact of exercise on nocturnal HRV and autonomic dysfunction in PD.

In a randomized, controlled clinical trial, individuals with PD were randomized to exercise (N=14) or SH (N=9). The exercise intervention involved a combination of resistance training and bodyweight functional exercises. We analyzed baseline demographics, sleep architecture, disease characteristics, and polysomnography-derived ECG data. We conducted frequency-domain analysis of HRV from 2-minute, abutting NREM and REM segments. Changes in HRV outcomes, including low-frequency (LF) power, high-frequency (HF) power, and LF/HF ratio, from pre- to post-intervention were compared between groups.

Age, sex, education, sleep architecture, and disease characteristics were similar between groups at baseline. The exercise group exhibited significantly increased REM LF power (p=0.025), significantly decreased REM HF power (p=0.025), and insignificantly increased REM LF/HF ratio (p=0.154) at 16-weeks compared to baseline. The group x time interaction was not significant (REM LF p=0.402, REM HF p=0.396, REM LF/HF p=0.718). HRV did not change in the SH group.

After exercise training, individuals with PD exhibited increased sympathetic influence on REM-related HRV. This suggests that exercise may have a role in addressing nocturnal autonomic imbalance in PD. Further study in a larger cohort is needed to better characterize the extent of exercise’s effect on sleep-related HRV.