Resting heart rate and heart rate variability in long COVID: what the patterns show - and what they don't
Why resting heart rate and HRV often shift in long COVID, what recent research shows about autonomic nervous system regulation, and where wearable data reaches its limits.
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If you live with long COVID and track your health with a wearable, you have probably noticed patterns in your data: a resting heart rate that's higher than it was before your infection, or heart rate variability (HRV) that looks lower than it used to be. This is not random - and you are not imagining it. Sam reads these values from Apple Health and shows them against your personal baseline, giving you a concrete reference point instead of just a feeling.
What might be behind these changes
One explanation that appears repeatedly in long COVID and ME/CFS research is dysregulation of the autonomic nervous system. This system manages heart rate, digestion, temperature control, and the shifts between activation (sympathetic) and recovery (parasympathetic) that happen without conscious effort. When this balance goes wrong, resting heart rate can become persistently elevated and your capacity to recover can diminish.
Important note: this is one plausible explanation among several active lines of research, not a proven cause of all long-COVID symptoms. Research is ongoing - including work at Charité Fatigue Centre in Berlin, led by Prof. Carmen Scheibenbogen, which specialises in diagnosing ME/CFS following infection.
What current research shows about HRV
A 2025 study published as a preprint continuously measured heart rate and HRV in 127 long-COVID patients and 21 healthy controls during everyday life. The findings: HRV was lower during sleep in the affected group and remained noticeably suppressed for longer after moderate-to-heavy exertion compared to controls - a pattern linked to post-exertional malaise (PEM).
To put this in context: this is a preprint, not yet through formal peer review at the time this article was written. The results show evidence of a real, measurable pattern - a signal, not a validated diagnostic measure and not a basis for self-diagnosis.
Why your own baseline matters more than population norms
Population averages don't tell you much when it comes to long COVID. What matters far more is comparison with your own data from before infection or from recent weeks: Is your resting heart rate drifting up over several days? Is your HRV dropping sharply after a more active day and recovering more slowly than before?
This kind of trend-watching is exactly what a wearable can do in daily life - without you having to manually track numbers every morning.
Heart racing and dizziness on standing: when circulation signals matter
Some long-COVID patients report that their heart rate spikes unusually on standing or that they feel dizzy when they get up. This may indicate orthostatic intolerance - best known as Postural Orthostatic Tachycardia Syndrome (POTS), where the circulation no longer adjusts normally when you shift from lying or sitting to standing.
An Apple Watch can make such heart-rate spikes visible over time - for instance, if the reading right after standing is noticeably higher than when lying down. But a reliable POTS diagnosis requires more: a clinical standing test or tilt-table exam where heart rate and blood pressure are monitored over several minutes. If you find yourself repeatedly experiencing heart racing, dizziness, or near-fainting on standing, that is a good reason to talk to your primary care doctor.
Where Sam Health fits in
Sam reads resting heart rate, HRV, sleep, and activity from Apple Health and compares them with your personal baseline. You get a clear view of your trends without having to keep manual logs - especially valuable on days when you simply don't have the energy to track things yourself. The article on pacing in long COVID describes how some patients use such trends in their own pacing decisions - not to predict PEM, but as one of several signals.
Try Sam HealthDisclaimer
Sam is a wellness companion, not a medical device. Sam does not diagnose, treat, or prevent any illness and cannot predict post-exertional malaise. If you experience persistent or troubling symptoms, talk to a qualified medical professional, ideally one experienced in post-COVID or ME/CFS care.
Sources
- Robert Koch Institute: Long COVID - A Challenge for Public Health and Health Research
- Charité Fatigue Centre: Post-COVID Syndrome with Fatigue and Exercise Intolerance
- German Heart Foundation (Deutsche Herzstiftung): Post-COVID - Effects on Heart and Vessels
- medRxiv (Preprint, 2025): Wearable heart rate variability monitoring identifies autonomic dysfunction and thresholds for post-exertional malaise in Long COVID
Frequently Asked Questions
Why does resting heart rate often increase with long COVID?+
One mechanism researchers frequently discuss is dysregulation of the autonomic (nervous) system - the system controlling heart rate, digestion, and recovery in the background. Studies point to an imbalance between the sympathetic and parasympathetic branches of this system. This is one plausible explanation among several, not a definitively proven cause.
What does a low HRV reveal in long COVID?+
A 2025 study of 127 long-COVID patients and 21 healthy controls found HRV was lower during sleep and remained suppressed longer after moderate-to-heavy exertion compared to controls. This is a preprint, not yet peer-reviewed - it's evidence of a real, measurable pattern, not a validated diagnostic marker or basis for self-diagnosis.
Can I diagnose long COVID by tracking my HRV?+
No. A long COVID or post-COVID diagnosis depends on how long your symptoms last and how they present, based on RKI and AWMF criteria - not on individual wearable readings. HRV and resting heart rate can provide context, but they don't replace medical evaluation.
Is low HRV in long COVID dangerous?+
An abnormal HRV is a signal, not a diagnosis. If you experience persistent or troubling symptoms - especially heart racing, dizziness when standing, or chest pain - talk to your primary care doctor, ideally with a referral to a post-COVID clinic or ME/CFS specialist centre.
Why does my heart race when I stand up after long COVID?+
This may indicate orthostatic intolerance, most commonly Postural Orthostatic Tachycardia Syndrome (POTS) - a pattern where your heart rate climbs unusually sharply upon standing because your circulation no longer adjusts the way it used to. An Apple Watch can show this pattern in your trend data, but a POTS diagnosis requires a clinical standing test or tilt-table examination.
How long does it take for resting heart rate to normalise after COVID infection?+
There is no standard timeline. For some people it drops within weeks; for others it stays elevated for months. This variability reflects the RKI's own definitions: symptoms from four weeks onward are called long COVID, from twelve weeks onward post-COVID.