Heart rate variability are a measurement of the intervals between heartbeats, and heart rate variability is a way to monitor the state of you’re autonomic nervous system. One specific way to measure heart rate variability is through an metric called RMSSD. RMSSD measure the variation in time between each individual heartbeat.
A person will see high heart rate variability when the intervals between heartbeats are inconsistent, and high heart rate variability indicate that the nervous system is flexible and responsive to the environment. Conversely, a person will see low heart rate variability when the intervals between heartbeats are very consistent, and low heart rate variability indicates that the nervous system is in a defensive or stress state. Many people attempt to compare their heart rate variability to universal standard, but comparing heart rate variability to a universal standard is not an effective method because heart rate variability are personal.
What Heart Rate Variability Means and How It Changes
DISCLOSURE: This post may contain affiliate links, meaning when you click the links and make a purchase, I receive a commission. As an Amazon Associate I earn from qualifying purchases.
A persons baseline heart rate variability changes based off age, and a person in their twenties will have different heart rate variability then a person in their fifties. Additionally, a person’s heart rate variability change because the autonomic nervous system undergoes naturally shifts as a person ages. Therefore, you should focus on your own personal trend in heart rate variability rather than focusing on an abstract or universal number.
Hormonal change also cause heart rate variability to fluctuate, and the menstrual cycle often drives these hormonal changes. During the follicular phase of the menstrual cycle, estrogen level rise, and rising estrogen levels often cause heart rate variability to increase. Because heart rate variability increase during the follicular phase, the follicular phase is often a good time for high intensity training.
However, when a person enter the luteal phase of the menstrual cycle, progesterone levels increase, and increasing progesterone levels can cause heart rate variability to decrease. A decrease in heart rate variability during the luteal phase doesnt mean you are losing fitness, but rather it means your body is shifting it’s metabolic priority. Pregnancy and the postpartum period also causes significant changes to heart rate variability.
During the first and second trimesters of pregnancy, a person may see elevated heart rate variability, but during the third trimester, the physical demand of pregnancy and a higher resting heart rate will cause heart rate variability to decrease. After a person give birth, the nervous system may take many month to stabilize, and heart rate variability will reflect the physiological rebuilding that occurs during the postpartum period. Furthermore, during perimenopause, estrogen withdrawal can cause heart rate variability to appear erratic.
During perimenopause, you should prioritize consistent habit like sleep and moderate movement because consistent habits helps to provide stability when heart rate variability is unpredictably. You can use heart rate variability to decide how hard you should train. If your heart rate variability are in a healthy zone, you can perform heavy lifting or high-intensity interval training.
However, if your heart rate variability drop significantly below your average, you should choose lower-intensity activities such as walking or restorative yoga. Pushing yourself to train intense when your heart rate variability is low can be counterproductive, and pushing yourself when heart rate variability is low can lead to overtraining or hormonal imbalance. To ensure that your heart rate variability measurements is accurate, you should take your measurements at the same time every day.
For example, you should take your heart rate variability measurements in the morning while you are in a fasted state and before you consume caffeine. Whether you use a smartwatch or a chest strap, you must maintain consistency in how you measure heart rate variability. Consistency in measurement allow you to use heart rate variability as a tool to understand your biology.
