Hormones are powerful chemicals in your body that influence just about everything. Your nervous system is no exception. Research has shown higher sympathetic nervous system activation in menopause. Put in simpler terms, there’s a higher amount of stress in menopause.
The sympathetic nervous system is part of your autonomic nervous system that regulates most unconscious bodily processes such as breathing, heart rate, blood pressure, digestion, and sexual function. Your autonomic system is divided into sympathetic and parasympathetic branches.
The sympathetic system keeps you alert and triggers the “flight or fight” response. This is balanced by the parasympathetic system that promotes rest. When you are eating, you want to be in a parasympathetic or relaxed state as that supports digestion, actually directing blood flow to your digestive tract.
In contrast, when you are stimulated or stressed, your sympathetic system is activated making you more alert, raises your heartrate, blood pressure and respiration while diverting blood away from your digestive tract. It’s preparing you to fight a predator or run away.
I share that to better explain why heartrate variability or HRV can be more nuanced in peri and postmenopause. HRV is the variation in heart beats, your heart does not beat at the exact same rate. Your rate may be 60 beats per minute, but you may have 1 second between beats, then 3 or 4 seconds between beats, averaging out to 60 beats a minute.
When you are stressed, or your sympathetic system is activated your heartrate may go up but the variation between beats goes down, lowering your HRV score. When you are at rest or in a more relaxed state, your HRV will increase.
HRV can be a great tool in assessing recovery and overall impacts of stress on your body. The trends are more important than the individual days typically. If you see your HRV trending down, you know to back off your training load as your recovery is not matching your training. Or maybe other life stress is ramping up and together with your training, you need more sleep or general recovery than normal.
Understanding that your hormones influence your nervous system, it makes sense that your HRV will fluctuate alongside hormonal changes. When you are in a high hormone or luteal phase – the week or so before your period, you might see your HRV decrease as progesterone lowers HRV. This drop in HRV is real, high progesterone (and high estrogen) leads to more inflammation and decreases recovery while increasing respiratory rate. That said, it’s important to remember that it’s a normal decline and may not indicate overreaching or poor recovery. I encourage every woman to adjust her training throughout her cycle, ideally adding a deload week during the high hormone week to account for this natural shift. This brings in an essential deload week every month that’s best aligned with natural physiology.
There’s not a lot of research currently on HRV in peri and postmenopause but having identified higher sympathetic activity in these phases, it’s not surprising that a lowering of HRV is typical. Again, this doesn’t make HRV obsolete, it’s about understanding what’s normal so you can adjust your interpretation and utility of these recovery tools.
In perimenopause, everything become erratic. Your cycles may be irregular, short or long, and you may not ovulate every month (or cycle) contributing to estrogen dominance. If you’ve been tracking HRV and heartrate up to this point, you can still use those metrics and should add in respiration rate and sleep quality. Take the average of the markers, do an honest assessment of how you are feeling and if you’re still in doubt, do your work out and adjust as you go if you’re not warming up well or performing the way you expect.
Once you’re officially in menopause, things are more consistent as your hormones stay consistently low. Research has shown HRV to trend lower in menopause and many women see a new, lower HRV baseline be established. Again, you will want to observe trends over day-to-day numbers and combine your HRV score with your respiration rate and sleep quality.
It can be difficult in perimenopause and postmenopause to know what should be changed or adjusted when cycles, moods, energy, libido, and sleep all become temperamental. Tracking helps. Tracking mood, sleep, and any hormonal symptom along with HRV and resting heart rate will give you the tools and insights into how your body is recovering or managing stress.
Remember, there is more stress occurring in your body during menopause. This needs to be accounted for in your overall selfcare. You can still train, crush your career, and show up fully for your family and chase all your goals. Adjusting selfcare or recovery routines, protein intake, sleep quality, and using your “NO” button more will help you stay in pursuit for years and decades!