Heart Rate Variability (HRV) is a way to measure how your body is handling stress and adapting to the world around you.
Even though we often think of our heart beating at a steady pace, the time between each heartbeat is always changing slightly. For example, if your heart is beating at 60 beats per minute, the beats are not exactly one second apart—some may be a little shorter, others a bit longer. This is completely normal and actually a sign of good health!
HRV is measured in milliseconds using special devices. With some proper analysis you can use it to understand how well your body is responding to different situations.
HRV varies from person to person—what’s normal for you might be different from someone else. It also changes over time based on factors like stress, fitness, and recovery. That’s why the most useful way to interpret HRV is by tracking your own trends rather than comparing to others. Establishing your personal baseline helps you understand what’s typical for you and makes your HRV data more meaningful and actionable.
Once you find your own personal baseline, you can compare the day to day data. In general, a higher HRV status means that your body is relaxed and recovering, while a lower HRV status usually signals stress or a fight-or-flight state.
HRV is calculated by measuring the time between heartbeats, or R-R intervals.
This can be done using a electrocardiogram (EKG) or by using a smartwatch (fitness tracker).
Fitness watches use time-domain methods to track your HRV. SDNN and RMSSD are the two most common ways smart watches track your HRV.
SDNN - is the square root of the variance of all normal R-R intervals during a set period. It is often calculated over a 24-hour period. SDNN is normally measured in milliseconds (ms).
RMSSD - is the square root of the average of the differences between successive heartbeats. RMSSD is typically measured over a shorter period of time. RMSSD is normally measured in milliseconds (ms).
Improving your HRV requires a well-rounded approach that supports your body, mind and emotions.
Here are some tips on improving your HRV Status:
Regular Exercise - Regular exercise, especially high-intensity interval training, boosts HRV and improves heart health. However, over-training can lower HRV, so balancing exercise and rest is key.
Quality Sleep - Quality sleep boosts HRV, while poor sleep lowers it. Aim for 7-9 hours nightly to support recovery and improve HRV.
Healthy Diet - A balanced diet with whole foods boosts HRV. Omega-3s from fish and nuts help, while processed foods and sugar can lower it.
Manage Stress - Stress lowers HRV by activating the sympathetic nervous system. Techniques like meditation, yoga, and deep breathing can help increase HRV by promoting relaxation. Regular stress management improves HRV and overall well-being.
Limit Alcohol and Caffeine - Too much alcohol and caffeine can lower HRV. Caffeine boosts heart rate, while alcohol slows the parasympathetic system. Limiting both can help.
Meditate - Meditation boosts HRV by reducing stress and activating the body's relaxation system. It lowers heart rate, balances the nervous system, and improves well-being. Regular practice makes the heart more adaptable to stress.