On average, yes, for all three. Across pooled studies, people with post-traumatic stress disorder (PTSD) had lower RMSSD RMSSD Root mean square of successive differences: an HRV metric built from how much each heartbeat interval differs from the next, in milliseconds. It mainly reflects vagal activity. More about RMSSD and high-frequency heart rate variability (HRV) at rest and a higher heart rate (Schneider and Schwerdtfeger, 2020). In 410 adults, the exhaustion part of burnout went with lower RMSSD (Kanthak and colleagues, 2017). In myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), a meta-analysis drawing on 64 studies found a resting heart rate Resting heart rate How many times your heart beats per minute while you are fully at rest. For adults it is usually 60 to 100 beats per minute, and lower in well-trained athletes. More about Resting heart rate about 4 beats a minute higher and lower high-frequency HRV (Nelson and colleagues, 2019). Each is a pattern across groups, not a test for anyone.
PTSD
The 2020 meta-analysis pooled studies comparing people with PTSD and healthy controls:
- At rest: lower RMSSD and high-frequency power HF power The variance of the heartbeat intervals that falls in the 0.15 to 0.40 Hz band, in ms²: the range of normal breathing. It mainly reflects vagal activity when breathing is 9 to 24 breaths a minute. More about HF power , which the authors read as lower parasympathetic Parasympathetic nervous system The "rest and digest" branch of the autonomic nervous system. It slows the heart, mainly through the vagus nerve, and drives most of the beat-to-beat variation in HRV. More about Parasympathetic nervous system activity; a medium-sized drop in SDNN SDNN The standard deviation of all NN intervals in a recording, in milliseconds. It measures overall variability, and its value depends strongly on how long the recording lasts. More about SDNN , meaning less variability overall; a small drop in low-frequency power LF power The variance of the heartbeat intervals that falls in the 0.04 to 0.15 Hz band, in ms²: rhythms repeating every 7 to 25 seconds. Once read as sympathetic activity, which is now disputed. More about LF power ; a higher LF/HF ratio LF/HF ratio LF power divided by HF power, with no unit. It was proposed as a gauge of balance between the sympathetic and parasympathetic systems, but research shows it cannot measure that reliably. More about LF/HF ratio ; and a higher heart rate.
- Under stress: a higher heart rate and lower high-frequency HRV than controls, both small effects.
The authors concluded that PTSD is linked with autonomic dysfunction. The size of the differences varied with study design, how PTSD was assessed and who was studied, which is a reminder that “PTSD” covers very different people and histories.
Burnout
Burnout is usually described as three things: emotional exhaustion, cynicism about work, and a sense of reduced accomplishment. The Dresden Burnout Study measured RMSSD in 410 adults (average age 42) during a blood draw, a recovery period and seated rest. Only exhaustion was linked with lower RMSSD, during the blood draw and at rest, after allowing for age and body mass. Cynicism and reduced accomplishment were not. The same analysis found RMSSD linked with the burnout-like symptoms of depression but not with its core features such as low mood. The authors suggested that reduced vagal function tracks exhaustion itself, whatever label the exhaustion carries (Kanthak and colleagues, 2017).
That matters for reading your own data. A low HRV with exhaustion fits burnout, but it fits short sleep, overtraining, illness and depression too. See does depression lower HRV? and HRV and stress.
ME/CFS
The 2019 meta-analysis gathered 64 studies of heart measures in ME/CFS against healthy controls. People with ME/CFS had:
- a resting heart rate about 4 beats a minute higher
- a larger heart rate rise on standing and during head-up tilt
- a lower high-frequency share of resting HRV and a higher LF/HF ratio
- a lower maximum heart rate during exercise, by about 14 beats a minute
The authors concluded that ME/CFS goes with altered autonomic control of the heart, and that these changes may be part of the condition rather than a cause. The orthostatic findings overlap with what is seen in postural tachycardia syndrome; see can HRV track long COVID or POTS?
How to read your own data
- Treat the number as a way to watch, not a verdict. Lower vagal HRV is common to many kinds of overload. It cannot tell PTSD from burnout from a bad month.
- Use weekly averages over months. Day-to-day noise is large. A slow rise alongside treatment, better sleep and less load is the fair comparison; the lesson on building your HRV baseline shows how.
- Pace, if you have ME/CFS. Many people with ME/CFS use heart rate and HRV to avoid overexertion and the crash that follows it. A morning reading well below your usual range is one input into a quieter day, alongside how you feel.
- Consider slow breathing. Across 58 randomised trials, HRV biofeedback HRV biofeedback A breathing practice in which you watch your heart rate live and breathe slowly, often near 6 breaths a minute, to make the heart's rise and fall with each breath as large as possible. More about HRV biofeedback had a small to moderate pooled effect, largest for anxiety and depression and smallest for PTSD (Lehrer and colleagues, 2020). It can sit alongside treatment, not replace it. See can breathing exercises raise HRV?
When to talk to a doctor
If flashbacks, nightmares, constant alertness, exhaustion that rest does not fix, or a crash after small efforts have lasted weeks, talk to a doctor or a mental health professional. Do not change any treatment because of a wearable reading. Get help straight away if you have thoughts of harming yourself. HRV cannot diagnose anything, and this page is not medical advice.