Heart-rate variability (HRV) is a measure of the small beat-to-beat variation in your resting heart rate, captured overnight by wearables like the Ring AIR and Ring PRO. Understanding your HRV helps assess autonomic nervous system balance \u2014 and a low or steadily declining HRV can signal accumulated stress, poor recovery, or developing cardiovascular risk.<\/p>\n\n\n\n
This guide shows median HRV by age decade for both men and women, drawn from over 510,000 Ring users across 77 million nights of sleep, and explains how to read your own number against your gender and age peers.<\/p>\n\n\n\n
HRV is the variation in time between consecutive heartbeats, measured in milliseconds. A higher HRV means the autonomic nervous system can switch smoothly between active and rest states. A lower HRV signals that the parasympathetic (rest-and-digest) arm is dampened, often by stress, poor sleep, illness, or aging.<\/p>\n\n\n\n
Most Ring users see HRV reported as RMSSD<\/strong> (root mean square of successive differences), measured overnight during sleep. RMSSD is one of the most commonly used time-domain HRV metrics; HRV norms vary substantially by the measurement window used (ultra-short, short-term, or 24-hour readings are not directly interchangeable) (Shaffer F, Ginsberg JP, Front Public Health<\/em> 2017, PMID: 29034226<\/a>).<\/p>\n\n\n\n Two factors consistently predict baseline HRV in overnight RMSSD studies \u2014 age and gender. The decade-by-decade decline with age is well-established (Umetani K et al., J Am Coll Cardiol<\/em> 1998, PMID: 9502641<\/a>). The gender effect, with men typically showing higher HRV than women in younger years, has been documented across multiple cohorts (Voss A et al., PLoS One<\/em> 2015, PMID: 25822720<\/a>). The Ring dataset confirms both at scale, with one finding the older literature didn’t quite show: the male-female gap stays roughly constant into older age.<\/p>\n\n\n\n The table below shows overnight HRV by age decade, split by gender, in the Ultrahuman Ring user population.<\/p>\n\n\n\nHRV by age and gender \u2014 the chart<\/h3>\n\n\n\n