What is Heart-Rate Variability and What’s a Good Score?

Heart-rate variability – it’s the health metric of 2025 and if you wear a tracking device, it’s likely you’ve experienced a little of the obsession first-hand. But what actually is it, why does it matter and what’s a good score?

HRV reflects the small differences in the time intervals between each heartbeat. If your heart beats 60 times per minute, it doesn’t necessarily mean one beat lands every exact second. Instead, the intervals fluctuate — sometimes a little longer, sometimes shorter. That variability is controlled by the autonomic nervous system, which constantly balances your body between sympathetic activity (the "fight or flight" response) and parasympathetic activity (the "rest and digest" state).

A higher HRV generally signals that your nervous system is adaptable and resilient. This adaptability is linked with better cardiovascular health, physical fitness and a greater capacity to recover from both physical and mental stress. On the other hand, a consistently low HRV can point toward fatigue, chronic stress, or a need for better recovery.

Unlike step counts or blood pressure readings, HRV doesn’t have a universal "healthy" number. It is profoundly individual, influenced by age, gender, fitness level, genetics, and even environmental factors such as altitude or climate.

Wearable companies like WHOOP and Oura have published large-scale population data to provide benchmarks. WHOOP’s research shows that HRV tends to peak in the mid-20s and declines gradually with age. The average 25-year-old sees an HRV around 78 milliseconds (ms). By the mid-30s, that number drops closer to 60 ms, and by the mid-40s, averages fall around 48 ms. By the time someone reaches their mid-50s, averages typically hover near 44 ms.

Context is everything — comparing your number against a single threshold doesn’t provide the full picture.

Unlike some health metrics that change only gradually, HRV can rise or fall overnight depending on the choices you make.

Poor sleep, irregular sleep patterns, or eating heavy meals close to bedtime can all lower HRV. Overtraining is another common factor: pushing hard in the gym without allowing for adequate recovery often results in suppressed HRV, a signal that your nervous system is under strain.

Alcohol, however, may be the single most influential lifestyle factor. WHOOP’s analysis of millions of nights of data found that even one drink can significantly lower HRV, and its effects can linger for up to five days. That means your Friday night out might still be affecting your recovery scores well into the following week.

Because HRV is so sensitive to daily fluctuations, experts recommend focusing less on individual numbers and more on long-term trends. A single night of poor sleep might drop your HRV significantly, but that doesn’t necessarily mean your overall health is deteriorating. Instead, look at the bigger picture: is your baseline moving upward over weeks and months? That’s where meaningful improvements show up.

Improving HRV comes down to supporting the body’s ability to recover and adapt. Consistent, good-quality sleep is the foundation. Training regularly while building in adequate recovery days helps balance load and resilience.

Stress-management practices — from meditation and breathing exercises to simply carving out downtime — can help shift the nervous system toward parasympathetic activity, raising HRV over time.

Nutrition also plays a role. A diet rich in whole foods, micronutrients, and healthy fats supports heart health and autonomic function. Certain supplements, including magnesium, omega-3 fatty acids, and adaptogens like ashwagandha, have been studied for their positive influence on stress and recovery systems, and may contribute to higher HRV in the long run.

Lifestyle is always the biggest driver, but targeted supplementation can offer support. In an independent study of NIGHT POWDER, 88% of participants who tracked their recovery with wearables reported improvements in recovery scores after just two weeks. While supplements are never a replacement for sleep or stress management, they can be a valuable tool in nudging HRV in the right direction.

When it comes to HRV, what matters most is not how your number compares to a generic benchmark but how it compares to your own baseline.

HRV is best used as a compass, not a competition. Pay attention to the trends and use your HRV as a guide to better understand how your body responds to stress, recovery, and lifestyle.

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