💗 What Happens to HRV in Midlife

What is happening to my HRV? It seems so low now. My doctor says it’s because I’m “getting old.” Is that right??

How can I get my HRV higher?

These are just a couple of the many messages I get from women in the community who are concerned that their HRV numbers from their Oura Ring, Whoop Strap, or other wearable are lower than they like. And I get it. HRV is held up as a metric of how “fit and ready” you are for everything you do. No one wants to see a “low” number. But it’s also important to put this number (and all numbers really) in context.

What is HRV

Let’s start at the beginning. HRV is simply the tiny variation in time between each of your heartbeats, measured in milliseconds. Though we tend to think of our heartbeats as metronomic–thump, thump…thump, thump–we actually want it to be a bit more variable, because that reflects adaptability. A higher HRV generally reflects a nervous system that can shift smoothly between “go” (sympathetic) and “slow” (parasympathetic, or recovery) modes, while lower HRV often shows that your body is dealing with more stress and has less flexibility to adapt. So, the number you see on any given morning isn’t a “grade” on your fitness, but a readout of how your whole system is coping with training and life.

Importantly, HRV is highly individual. It’s influenced by age and sex, and also by training history, genetics, and lifestyle. There is no single “good” number. Statistics from WHOOP show that the average heart rate variability for women is 62 milliseconds, with the average range for 25 year old females being around 45ms to 90ms and the average range for 45 year olds being 30ms to 55ms.

The best strategy is to look at your trend over time—is the number you’re seeing higher or lower than your usual baseline—rather than chasing a specific value or assuming your HRV should match your running buddy’s.

How Does it Change Across a Woman’s Lifespan

A new systematic review investigated HRV in women across reproductive life stages using real‑world wearables like Oura, Whoop, chest straps, and HRV apps. The authors pulled together 16 studies of more than 19,000 women, most of which focused on menstrual cycle phases and hormonal contraceptives with a smaller subset on perimenopause and postmenopause. For our purposes, that last piece is the most interesting, even though the evidence is less robust.

So what did they see? One study using Oura ring data found that women in their 40s and 50s, who were in the late reproductive or menopausal transition years, had lower nighttime HRV compared to younger women in their late teens to mid‑30s. In particular, a key HRV marker linked to “rest and recovery” nervous system activity (parasympathetic/vagal tone) was lower in the midlife group.

Another study of women in their mid‑40s to late 50s saw a similar pattern. The women who were still premenopausal had the strongest recovery‑side HRV signal, while both early and late postmenopausal women showed weaker recovery‑side HRV. At the same time, that study did not find big differences in some of the other standard HRV metrics, and a few of the more technical measures even looked a bit better in early postmenopause. A larger data set that included menstruating, perimenopausal, postmenopausal, and pregnant women also did not see big differences in a common “balance” ratio between stress and recovery across these groups.

The author’s ultimate takeaway is nuanced: on average, younger premenopausal women show a stronger recovery signal in their HRV than peri‑ and postmenopausal women, which tracks with what many women experience. Estrogen seems to support higher vagal tone, and life stages or phases with higher estrogen (e.g., premenopause, follicular phase) tend to show higher HRV, whereas low‑estrogen contexts (post‑menopause) show lower HRV in many, but not all, metrics. But still, it is hard to say how much of the 40+ changes are due to getting older and how much are due to changing hormones. HRV naturally drifts down with age in both women and men, and this review is a reminder that a 52‑year‑old’s numbers are not necessarily supposed to look like a 28‑year‑old’s. 

That said, training and other lifestyle factors also play a role here, and the authors of this systematic review acknowledge that variables like training load, psychological stress, alcohol intake, and sleep quality were rarely measured or reported in a standardized manner, so the findings may not perfectly reflect an active population.

That’s important because a small study of master sprinters and endurance athletes found that these active midlife women had resting HRVs that looked much more like that of young untrained adults than age‑matched non‑athletes—suggesting that regular training can largely offset the usual age‑related drop in autonomic function. In other words, if you see a number that is significantly lower than your baseline, it’s worth looking at the whole picture rather than chalking it up to age alone.

Menopause Symptoms and Life Load Matter

HRV is also affected by stress–and remember, stress is stress, whether from training or a night filled with sheet soaking sweats. During peri‑ and post‑menopause, changes in estrogen, sleep disruptions, hot flashes, mood shifts, and midlife stress piles can all nudge HRV lower or make it more volatile, reflecting increased autonomic strain.

If you have a lot of symptoms and/or stress, you’re bound to see some downward trends. So, the goal is to stabilize and improve it by addressing the root cause. Studies in athletes show that rest days and lower‑intensity training tend to raise HRV the next day, while heavy stress can push it down. For 40+ athletes, that means:

• If HRV is trending down over several days and you feel flat, it’s a good cue to dial down intensity and/or stressful volume and prioritize sleep and fueling.

• If HRV is stable or improving normally within your baseline and you feel good, that supports pushing harder days.

You can help give your HRV a boost by following generally healthy lifestyle behaviors. Practicing stress management, eating early and limiting alcohol so you can get quality, restorative sleep, and staying hydrated, all help.

HRV can be a useful metric to monitor your recovery after a big athletic event, but remember that an HRV score by itself doesn’t give the full picture of your “readiness”. While HRV is a proxy for global physiological stress, it is not specific to the muscles. HRV cannot reliably detect: local muscle fatigue or soreness, glycogen depletion in your muscles, or neuromuscular function decline (i.e. how well your muscles and nervous system are coordinating for strength and power output). 

Treat your HRV as just one data point of many–and never forget the most important metric: how you feel!