{"id":6782,"date":"2026-09-01T22:23:43","date_gmt":"2026-09-01T22:23:43","guid":{"rendered":"https:\/\/www.ahmetozyigit.com\/?p=6782"},"modified":"2026-09-01T22:47:07","modified_gmt":"2026-09-01T22:47:07","slug":"kalp-hizi-degiskenligi-hrv","status":"publish","type":"post","link":"https:\/\/www.ahmetozyigit.com\/en\/kalp-hizi-degiskenligi-hrv\/","title":{"rendered":"Heart Rate Variability (HRV): Balance of Nervous System Stress and Recovery"},"content":{"rendered":"
\"\"<\/figure>\n\n\n\n

\n HRV, or heart rate variability., <\/strong>It is a measurement that shows how variable the time between our heartbeats is.\n<\/p>\n\n\n\n

\n Our hearts don't beat at perfectly fixed intervals like a metronome. For example, if your heart beats 60 times a minute, that doesn't mean there's exactly one second between each heartbeat. There might be 0.9 seconds between one beat and 1.1 seconds between the next.\n<\/p>\n\n\n\n

\n These millisecond variations between heartbeats are what we call HRV (Heart Rate of Viability).\n<\/p>\n\n\n\n

So why is this figure so important?<\/strong>\n<\/p>\n\n\n\n

\n Because HRV gives us important information about the regulatory activity of our autonomic nervous system on the heart.[1,2] The sympathetic side of our autonomic nervous system prepares us for situations such as stress, intense exercise or danger. The parasympathetic system, on the other hand, plays an important role in regulating the heart during periods of relaxation, rest, and recovery, especially via the vagus nerve.\n<\/p>\n\n\n\n

\n What we expect from a healthy autonomic nervous system is not that it is constantly parasympathetic or constantly sympathetic. What is important is its capacity to switch from one system to another when necessary and to adapt to changing conditions.\n<\/p>\n\n\n\n

Is a higher HRV always better?<\/strong>\n<\/p>\n\n\n\n

\n In general, within a person's own physiological conditions, higher HRV is associated with stronger vagal modulation and better cardiac autonomic adaptation.[1,2] However, it is important to make a crucial distinction here. There is no universal rule that the higher your HRV, the healthier you are.\n<\/p>\n\n\n\n

\n HRV can be affected by many factors such as age, genetic makeup, physical condition, respiratory rate, heart rate, medications used, alcohol consumption, sleep, illnesses, and even the time of day the measurement is taken. Furthermore, not all devices measure HRV using the same method. Some use different HRV parameters such as RMSSD, others SDNN. Therefore, directly comparing two HRV values obtained from different devices may not always be accurate. The effect of age is particularly significant. Large population studies have shown that HRV generally decreases with age.[3] Thus, an HRV of 30 milliseconds may be quite low for a young and very fit person, while it may be a perfectly normal value for another 75-year-old. Therefore, reference ranges vary depending on age and health status. The important thing is for individuals to base their average level on their own performance rather than comparing themselves to others, and to be able to improve upon it. \n<\/p>\n\n\n\n

What does a low HRV tell us?<\/strong>\n<\/p>\n\n\n\n

\n One of the most valuable aspects of HRV is that it helps us track changes in the body's stress and recovery load. We see a decrease in HRV during periods of intense psychological stress, insufficient sleep, illness, excessive exercise, and inadequate recovery.\n<\/p>\n\n\n\n

\n For example, a meta-analysis of randomized studies examining sleep deprivation published in 2025 evaluated 11 studies and 549 individuals. It was shown that sleep deprivation significantly reduces the RMSSD value, which is closely related to parasympathetic activity.[4] In other words, we can observe that HRV is low in people who have poor sleep quality, do not get enough hours of sleep, or have insufficient deep and REM sleep even if they spend enough hours in bed.\n<\/p>\n\n\n\n

\n The relationship between chronic inflammation and HRV is also quite remarkable. A comprehensive meta-analysis published in 2019 showed that parameters such as SDNN and high-frequency HRV were inversely related to inflammation markers: in general, as HRV decreased, inflammatory markers tended to increase.[5]\n<\/p>\n\n\n\n

\n This doesn't mean that low HRV causes inflammation. However, it shows that the physiological relationship between the autonomic nervous system, immunity, and inflammation is much closer than we thought. In short, these studies show that when our body's immune system is under stress, our transitions between stress and relaxation modes may also be problematic. \n<\/p>\n\n\n\n

The relationship between HRV and the risk of premature death.<\/strong>\n<\/p>\n\n\n\n

\n HRV is not just a \u201cwellness\u201d statistic used for stress or sleep monitoring. There is also extensive data investigating its relationship with long-term health outcomes. A systematic review and meta-analysis published in 2022 evaluated 32 studies, two individual participant datasets, a total of 37 samples, and 38,008 individuals.[6] As a result of these studies, it was found that low HRV was associated with a higher risk of death. Moreover, this relationship continued to be observed in different age groups, in women and men, in different populations, and at different HRV measurement times.[6] In short, it is not a coincidental finding or a finding specific to a particular group. \n<\/p>\n\n\n\n

\n Therefore, viewing HRV solely as a measure answering the question "Am I stressed today?" would be incomplete. HRV is also a biological marker carrying long-term prognostic information about our cardiac and autonomic nervous system health. Of course, here we must distinguish between correlation and causality. We cannot say that low HRV alone causes premature death. Low HRV can also be seen as a reflection of underlying cardiovascular, metabolic, or systemic problems. But in any case, what cannot be measured cannot be managed. Therefore, knowing our HRV is meaningful information for managing underlying problems. \n<\/p>\n\n\n\n

Can we increase HRV?<\/strong>\n<\/p>\n\n\n\n

\n The aim should not be to artificially increase the HRV number, but to improve the health of the physiological system reflected by HRV. Regular exercise is one of the best examples of this. In a meta-analysis of randomized controlled trials published in 2024, 16 studies and 623 healthy adults were evaluated. Regular exercise resulted in significant improvement in all parameters of SDNN, RMSSD and high-frequency HRV. The standardized effect size was calculated as 0.84 for RMSSD and 0.89 for high-frequency HRV.[7] In other words, regular exercise is quite beneficial for the autonomic nervous system.\n<\/p>\n\n\n\n

\n However, there is a paradox here. While exercise can improve HRV in the long term, very intense exercise and insufficient recovery can lower your HRV in the short term. Therefore, the goal is not just to exercise more; it is to strike the right balance between exercise and recovery. For example, if your HRV is low and you aim to improve it through exercise, it may be important that your exercise load is appropriate for your current health status, that there is sufficient recovery time between exercises, and perhaps that you exercise early in the morning rather than close to bedtime. This last point is especially important for people who have sleep problems. \n<\/p>\n\n\n\n

\n Regular physical activity, adequate sleep, good metabolic health, stress management, avoiding excessive alcohol consumption, and allowing sufficient recovery time after exercise are important for a healthier autonomic profile in the long term.\n<\/p>\n\n\n\n

Is HRV a longevity score?<\/strong>\n<\/p>\n\n\n\n

\n It would be inaccurate to view HRV alone as a "longevity score." Cardiorespiratory capacity, muscle strength and mass, metabolic health, blood pressure, cardiovascular risk factors such as ApoB, sleep, and many other variables determine a long and healthy life.\n<\/p>\n\n\n\n

\n HRV is just one of them.\n<\/p>\n\n\n\n

\n It allows us to monitor the dynamic balance between stress and recovery in our bodies on a daily basis. It's important to be able to activate when stress is needed and return to recovery mode when the stress is gone. HRV is one of the measurable windows into this adaptive capacity.\n<\/p>\n\n\n\n

Sources<\/strong>\n<\/p>\n\n\n\n

1. Gullett N, et al. (2023).<\/strong> Heart rate variability (HRV) as a way to understand associations between the autonomic nervous system (ANS) and affective states: A critical review of the literature. International Journal of Psychophysiology, 192<\/em>35\u201342.\n
\n DOI: https:\/\/doi.org\/10.1016\/j.ijpsycho.2023.08.001<\/a>\n<\/p>\n\n\n\n

2. Maki KA, et al. (2024).<\/strong> An Integrative Literature Review of Heart Rate Variability Measures to Determine Autonomic Nervous System Responsiveness Using Pharmacological Manipulation. Journal of Cardiovascular Nursing, 39<\/em>(1), 58\u201378.\n
\n DOI: https:\/\/doi.org\/10.1097\/JCN.0000000000001001<\/a>\n<\/p>\n\n\n\n

3. Tegegne BS, et al. (2020).<\/strong> Reference values of heart rate variability from 10-second resting electrocardiograms: the Lifelines Cohort Study. European Journal of Preventive Cardiology, 27<\/em>(19), 2191\u20132194.\n
\n DOI: https:\/\/doi.org\/10.1177\/2047487319872567<\/a>\n<\/p>\n\n\n\n

4. Zhang S, et al. (2025).<\/strong> Effects of sleep deprivation on heart rate variability: a systematic review and meta-analysis. Frontiers in Neurology<\/em>.\n
\n DOI: https:\/\/doi.org\/10.3389\/fneur.2025.1556784<\/a>\n<\/p>\n\n\n\n

5. Williams DP, et al. (2019).<\/strong> Heart rate variability and inflammation: A meta-analysis of human studies. Brain, Behavior, and Immunity, 80<\/em>219\u2013226.\n
\n DOI: https:\/\/doi.org\/10.1016\/j.bbi.2019.03.009<\/a>\n<\/p>\n\n\n\n

6. Jarczok MN, et al. (2022).<\/strong> Heart rate variability in the prediction of mortality: A systematic review and meta-analysis of healthy and patient populations. Neuroscience & Biobehavioral Reviews, 143<\/em>, 104907.\n
\n DOI: https:\/\/doi.org\/10.1016\/j.neubiorev.2022.104907<\/a>\n<\/p>\n\n\n\n

7. Amekran Y, El Hangouche AJ. (2024).<\/strong> Effects of Exercise Training on Heart Rate Variability in Healthy Adults: A Systematic Review and Meta-analysis of Randomized Controlled Trials. Cureus, 16<\/em>(6), e62465.\n
\n DOI: https:\/\/doi.org\/10.7759\/cureus.62465<\/a>\n<\/p>\n\n\n\n

<\/p>","protected":false},"excerpt":{"rendered":"

HRV, yani kalp h\u0131z\u0131 de\u011fi\u015fkenli\u011fi veya heart rate variability, kalp at\u0131\u015flar\u0131m\u0131z aras\u0131ndaki s\u00fcrenin ne kadar de\u011fi\u015fken oldu\u011funu g\u00f6steren bir \u00f6l\u00e7\u00fcmd\u00fcr. Kalbimiz bir metronom gibi tamamen sabit aral\u0131klarla atmaz. \u00d6rne\u011fin kalbiniz dakikada 60 kez at\u0131yorsa, bu her iki kalp at\u0131\u015f\u0131 aras\u0131nda tam olarak 1 saniye oldu\u011fu anlam\u0131na gelmez. Bir at\u0131m aras\u0131nda 0,9 saniye, bir sonrakinde 1,1 saniye […]<\/p>","protected":false},"author":2,"featured_media":6787,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-6782","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-genel"],"blocksy_meta":[],"_links":{"self":[{"href":"https:\/\/www.ahmetozyigit.com\/en\/wp-json\/wp\/v2\/posts\/6782","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.ahmetozyigit.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.ahmetozyigit.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.ahmetozyigit.com\/en\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ahmetozyigit.com\/en\/wp-json\/wp\/v2\/comments?post=6782"}],"version-history":[{"count":4,"href":"https:\/\/www.ahmetozyigit.com\/en\/wp-json\/wp\/v2\/posts\/6782\/revisions"}],"predecessor-version":[{"id":6789,"href":"https:\/\/www.ahmetozyigit.com\/en\/wp-json\/wp\/v2\/posts\/6782\/revisions\/6789"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.ahmetozyigit.com\/en\/wp-json\/wp\/v2\/media\/6787"}],"wp:attachment":[{"href":"https:\/\/www.ahmetozyigit.com\/en\/wp-json\/wp\/v2\/media?parent=6782"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ahmetozyigit.com\/en\/wp-json\/wp\/v2\/categories?post=6782"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ahmetozyigit.com\/en\/wp-json\/wp\/v2\/tags?post=6782"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}