Heart rate variability (HRV) is a vital measure of the autonomic nervous system’s resilience, reflecting how well you can balance stress responses. Research suggests HRV can predict mortality and help control stress reactions. But what does your HRV reading mean, and how can you improve it?
Technically, HRV measures the millisecond-by-millisecond change in heart beat intervals. It’s a proxy of stress and reflects our autonomic nervous system’s interaction between the sympathetic (fight-or-flight) and parasympathetic (chill) systems.
Ideally, these dueling systems interact and balance to keep us ready to react but not overreact to stress. A higher HRV indicates a healthier stress response, with more input from the parasympathetic system. However, HRVs can vary greatly by age, with some people having average ranges as low as 5 milliseconds or as high as 230 milliseconds.
To determine your typical HRV, use several months’ worth of data from your smartwatch or other wearable device. Be aware that HRVs spike and drop precipitously during a single day, so knowing your average range over months provides a baseline.
A substantial, prolonged HRV decline may signal something is wrong, such as illness, overtraining, or work-related strains. To raise your HRV, focus on finding and facing the issue causing the decline. This can involve adjusting training regimens, managing stress through meditation and slow breathing, or addressing lifestyle habits like exercise, eating well, and sleeping enough.
By understanding and improving your HRV, you’ll be better equipped to handle stress and maintain overall quality of life. Make HRV a key metric in tracking your health program and watch your journey towards improved resilience and wellness.
Source: https://www.washingtonpost.com/wellness/2025/08/19/heart-rate-variability-stress-longevity