Reasons Your HRV Is Low & How To Improve It Over Time

It's hard to remember a time before fitness trackers. These days, many people start the morning by reviewing their sleep score and end the night with a quick step count check. Recently, a new metric has gone mainstream on trackers: Heart rate variability (HRV). No longer reserved for athletes and biohackers, the masses are starting to use HRV to gauge recovery, stress, and healthspan. 

Unlike a metronome, your heart doesn’t beat in a perfect, regular rhythm. Heart rate variability is an important metric to track because it provides valuable insight into how your autonomic nervous system is doing. 

HRV is the time (measured in milliseconds) between each heartbeat and the variation in time between beat-to-beat intervals.

“For example, if your heart rate during a walk is 120 beats per minute, it’s not as if your heart is always beating twice every second with evenly spaced time between beats,” explains exercise physiologist Rachelle Reed, Ph.D. “Rather, there could be .15 seconds between two beats and .35 between others. You’re likely unaware of these small fluctuations.” 

A high HRV score means more variability between each heartbeat and indicates that your body responds and adapts well to stress and physical activity.

On the other hand, A low HRV score may indicate an imbalance in your autonomic nervous system1 and can be a predictor of risk disease and mortality2. A low HRV is associated with inflammation and inflammation-based diseases, chronic pain, fatigue, and other stress-related conditions. 

Because HRV is a highly personal metric influenced by many factors, some of which you can’t control, like sex and age, it’s hard to pinpoint an optimal HRV for everyone. 

“Generally speaking, a higher HRV is considered to be more favorable than a lower one,” says Reed. But she adds that it’s important to remember that ‘high’ or ‘low’ HRV is relative to the person.

“There is an association between lower HRV and lower fitness and/or older age—but even so, HRV is highly variable between people—so it's important not to get hung up on your number compared to someone else's,” says Deehan. “It's much more meaningful to track your HRV consistently over time (think months and years) and understand your own ranges and patterns and what this means.” 

Even with all the healthy practices in the world, your HRV may not massively jump up from this baseline. As longevity-focused doctor Peter Attia, MD notes on his podcast, The Drive, it's difficult to sway your number more than 50% (so if you start with an HRV of 40, 60 may be as high as you can reasonably go).

Healthy women typically have a lower HRV3 than their male counterparts, especially before age 30. This gender difference decreases with age and disappears after 50 years of age. 

All this said, WHOOP, a health and fitness tracker that monitors HRV, estimates that across its users, the middle 50% of 20-25-year-olds usually fall in the 55-105 millisecond range, while 60-65-year-olds are normally between 25-45 milliseconds.

The average heart rate variability for all WHOOP members is 65 for men and 62 for women. For 25-year-olds, it’s 78, for 35-year-olds it’s 60, for 45-year-olds it’s 48, and for 55-year-olds it’s 44.

Gabrielle Manto, D.C, a prenatal and pediatric chiropractor, collects HRV data from all her patients, including infants, active adults, and people with rare genetic disorders. She is currently collecting data on HRV trends during the perinatal period (around the time of conception, pregnancy, and postpartum) and during each phase of the menstrual cycle. 

In addition to longer-term factors, there are a few reasons your HRV could dip from day to day, including dehydration6, illness7, poor sleep8, and even flying9.

According to user data from WHOOP, when members report consuming alcohol, their HRV drops by an average of 22 milliseconds the next day. Their research has also discovered that the lingering effects of alcohol in your system may continue to suppress your heart rate variability for four to five days.

The good habits that form a healthy lifestyle, like exercise, hydration, a balanced diet, and sleep, are all associated with increased heart rate variability scores. 

“Generally speaking, maximizing health-promoting behaviors like the AHA’s Life’s Essential 811 is linked to improved health outcomes like lower risk for most chronic diseases and certain cancers, improved fitness levels, etc.,” says Reed. “So working to incorporate small changes day to day can add up to a big return on investment in the long run—improved HRV scores included."

While more research needs to be done in this area, one study found that higher intakes of leafy greens, especially spinach and kale, are associated with higher HRV scores. A Mediterranean diet, omega-3 fatty acids, B vitamins, probiotics, and polyphenols have been shown to benefit HRV acutely and in the longer term12. 

“Rather than focusing on a specific exercise or two, it’s important to zoom out and remember that increasing fitness levels overall is linked to improved health outcomes and better HRV measurements,” says Reed. “If you’re starting from scratch with an exercise program, my first and most important piece of advice is that all movement counts!”  

Slow-paced diaphragmatic breathing (less than 10 breaths per minute) has been shown to increase heart rate variability15. Another option is to inhale for four seconds, hold your breath for two seconds, and exhale for four seconds. 

The gold standard for measuring HRV is a multi-lead electrocardiogram (ECG). Obviously, ECGs are not accessible to the general public and are cost-prohibitive.

There are single-lead ECG or photoplethysmography (PPG) wearable devices you can purchase to measure your HRV at home, though these devices have varying degrees of accuracy16. Here are six heart rate variability monitors thought to be the most accurate.

“Wearable trackers like the Oura Ring and the WHOOP offer metrics surrounding HRV,” says Reed. Deehan also recommends the HRV4training app, which allows you to measure your HRV using your camera phone.

Reed says that because HRV reflects acute and longer-term health behaviors and stressors, it’s important to look for trends over time rather than obsessing over data on any given day.

It's also important to be consistent about when you're measuring HRV. “The key here is to... keep the same routine each day because very small changes can affect your HRV—like doing the dishes your kids left in the sink, or doom-scrolling, or consuming caffeine," says Deehan. She recommends measuring HRV right after you wake up to account for these shifts.

Deehan adds that if you do use multiple methods to measure HRV (e.g., a fitness tracker and a camera phone), it's best not to try and compare the numbers to each other. "Different algorithms and sensors can give different values," she says.

If you’ve noticed a lot more people talking about heart rate variability lately, you’re not alone.

Measuring heart rate variability (HRV) has become a trending topic over the last few years, with hashtags like #heartratevariability and #heartratevariabilitytraining having 1.9 million and 66.7 thousand views on TikTok, respectively. And according to Google Trends, there’s been a steady surge in popularity for this topic since 2016, with a significant jump in searches in 2022 and 2023. 

Xianghong Arakaki, MD, Ph.D., an Assistant Professor of Neuroscience and Head of the Cognition and Brain Integration Lab (CBIL) at Huntington Medical Research Institutes, says there are a few reasons for the increasing buzz around this metric.

“We are more aware of our health than before and are aware of improving overall health for prevention before symptomatic disease occurs,” Arakaki tells mindbodygreen. “And HRV has a tight link with cardiovascular condition, cognitive status, and overall health."

Arakaki adds that the tech developments around wearable devices also make it easy to monitor HRV non-invasively, and scientific publications on HRV have increased almost exponentially in recent years. 

Heart rate variability is likely being influenced by factors we don’t yet know about, Deehan notes. Researchers are currently looking to do more research on how our microbiome, diet, or environmental pollutants may influence HRV.

“I’ve been tracking mine for years on multiple devices, and sometimes I can understand the fluctuations (like my recent travel or if I have a few glasses of wine at dinner), but sometimes it goes up or down, and I am unable to tie it to anything specific,” explains Deehan.