Nocturnal HRV
milliseconds
HRV recorded during sleep, used as the primary autonomic input to the Recovery Score.
Typical optimal range 45 ms - 105 ms
Population median 58 ms
Key factors
- Prior day exertion and stress
- Nutrition timing and quality
- Sleep environment quality
What affects this metric
- Menstrual cycle phase shifts it across the month.
- Alcohol, late meals, and late training all suppress overnight HRV.
- Illness and psychological stress lower it.
- It is the most heavily weighted input to Recovery.
References
Peer-reviewed sources supporting the key factors, contributing factors, and typical optimal range shown above.
- Shaffer F, Ginsberg JP. An overview of heart rate variability metrics and norms. Frontiers in Public Health. 2017;5:258. doi.org/10.3389/fpubh.2017.00258
- Plews DJ, Laursen PB, Stanley J, Kilding AE, Buchheit M. Training adaptation and heart rate variability in elite endurance athletes: opening the door to effective monitoring. Sports Medicine. 2013;43(9):773–781. doi.org/10.1007/s40279-013-0071-8
- Pietilä J, Helander E, Korhonen I, Myllymäki T, Kujala UM, Lindholm H. Acute effect of alcohol intake on cardiovascular autonomic regulation during the first hours of sleep. JMIR Mental Health. 2018;5(1):e23. doi.org/10.2196/mental.9519
- Schmalenberger KM, Eisenlohr-Moul TA, Jarczok MN, et al.. Menstrual cycle changes in vagally-mediated heart rate variability are associated with progesterone: evidence from two within-person studies. Journal of Clinical Medicine. 2020;9(3):617. doi.org/10.3390/jcm9030617
This guide is general information, not medical advice. Talk to your clinician about your own results.