The Myth of the “Supermom” Debunked by Data

Three months after giving birth, I insisted on doing “everything myself”: feeding the baby 2–3 times a night, taking care of the baby, doing housework, and working remotely during the day. I felt like I “could still handle it.”

But the smartwatch on my wrist didn’t see it that way. For seven consecutive days, it sent the same alert: “Your HRV (heart rate variability) has been 30% below your personal baseline for several days. We recommend increasing your rest time.”

What is HRV? Simply put, it’s a measure of the balance in the autonomic nervous system. High HRV indicates a “relaxed, recovered state,” while low HRV indicates a “stressed, fatigued state.” The normal HRV range for adult women is typically between 30 and 50 ms. Mine, however, had dropped to 19 ms.

According to a 2023 paper in 《Clinical Research in Obstetrics and Gynecology》, the average HRV of postpartum women in the first three months is 35% lower than before pregnancy, and for sleep-deprived mothers, HRV can drop to less than 50% of the normal range. Chronically low HRV is associated with an increased risk of postpartum depression and cardiovascular disease.

I adjusted my schedule based on the watch’s recommendations, and my HRV returned to 35 after three weeks.

I showed my OB-GYN the watch’s HRV data and sleep analysis report. She glanced at them and said, “Your body is telling you that you need help. It’s not a ‘suggestion’—it’s a ‘need.’”

Following the watch’s recommendations, I made three changes:

Change 1: Accepting Help—A “Rotation System” for Night Feedings

Before, I couldn’t bear to wake my husband. Now, I pump and store milk in the fridge at 10 p.m., and my husband bottle-feeds the baby between 1 and 3 a.m., while I handle the 5 to 7 a.m. feeding. The watch showed that my continuous sleep duration increased from 2 hours to 4.5 hours.

After implementing the shift system for a week, my HRV rose from 19 to 24.

Change 2: Taking “micro-breaks” during the day

The watch has a “relaxation reminder” feature—when it detects two consecutive hours of activity and consistently low HRV, it sends a notification suggesting “take three minutes to breathe deeply.” I used to ignore this reminder, but now I actually put down whatever I’m doing, close my eyes, and take deep breaths.

After each 3-minute deep-breathing session, my HRV instantly increases by about 10–15% and remains elevated for approximately 30 minutes.

Change 3: Reducing Exercise Intensity

I resumed running six weeks postpartum, but my watch consistently showed my “recovery status” as “poor.” My doctor advised me to switch from running to walking and reduce the intensity from “moderate” to “light.”

After reducing the exercise intensity, my HRV no longer experienced a “post-exercise plunge,” and my nighttime recovery accelerated.

Why does HRV decrease after childbirth? There are three main reasons:

Fragmented sleep: Waking up multiple times during the night keeps the sympathetic nervous system continuously activated

Hormonal changes: Elevated prolactin and decreased estrogen affect autonomic nervous system regulation

Physical recovery: Tissue damage caused by childbirth is still healing, consuming energy

The American College of Obstetricians and Gynecologists (ACOG) 2024 Postpartum Care Guidelines have, for the first time, included a recommendation for “using wearable devices to monitor postpartum fatigue,” recognizing that HRV can serve as an objective indicator to assist in assessing postpartum recovery status.

Three weeks later, my HRV had rebounded to 35. Although it’s still a ways off from the 45 I had before pregnancy, I’ve learned to stop trying to be a “supermom.” That number on my watch is my body’s honest reflection.

Postpartum isn’t a competition to see who can push themselves the hardest.

The Venus Smart Shop watch has helped me recognize my body’s distress signals and taught me to accept help.