SAYA
What evening resting heart rate means
Your evening resting heart rate (eRHR) is how low your heart rate settles in the last hour before you fall asleep. It reflects how much load your body is still carrying at bedtime: digestion, a late workout, alcohol, stress — or, on a good evening, very little.
Why the hour before sleep matters
The state you go to bed in shapes the start of the night:
- A heart rate that stays elevated at night is linked to less restorative sleep and, in long-term studies, to worse health outcomes [1].
- Pre-sleep heart-rate variability can carry a lot of information: in a 2025 study of national-level athletes, pre-sleep HRV measures distinguished chronic insomnia with high accuracy and predicted measures of sleep continuity [2].
The evening resting heart rate is a simple way to read that pre-sleep state every day, without an extra measurement.
How SAYA measures it
SAYA reads your heart rate from your Garmin — no button to press:
- Window: from 70 to 10 minutes before your usual sleep onset.
- Smoothing: a 5-minute rolling average removes short spikes, such as getting up for a glass of water.
- Value: the lowest settled value in that window is your evening resting heart rate.
- Comparison: SAYA compares it with your personal 7-day resting heart rate baseline — not with a population table.
How it relates to overnight recovery
In SAYA, the evening resting heart rate plays two roles:
- In the Recovery Score (10%). Up to 3% above your baseline counts as full marks. At 20% above, the component drops to 40 of 100 points; at 40% above, to zero.
- As a habit signal. SAYA compares your evening resting heart rate with your sleep and recovery outcomes, so you can see how strongly it goes along with your nights.
An elevated evening value often goes together with a larger HRV-Incline: a body that is still running hot at bedtime needs longer to switch into recovery.
Evening vs. morning resting heart rate
| Evening resting heart rate | Morning resting heart rate | |
|---|---|---|
| When | Last hour before sleep | During the night / on waking |
| Describes | The load you take to bed | How the night went |
| Can you act on it? | Yes, the same evening | Only the next evening |
Both are useful, and SAYA uses both. The morning value summarizes the result; the evening value shows where the night starts.
What you can do with it
A high evening value isn't a verdict — it's a prompt. A single session of slow, paced breathing measurably raises parasympathetic activity [3]. Over time, your data shows which evening habits go along with a lower evening resting heart rate for you: an earlier dinner, a lighter workout, less screen time, no nightcap. See personal sleep analytics.
Limitations and individual differences
- Absolute values differ widely. 44 bpm can be excellent for one person and unusual for another. Only your own baseline gives the number meaning.
- It needs a calm phase. If you are active until you fall asleep, there's no settled value to read.
- Sensor quality matters. A loose watch or a lot of movement makes readings less reliable.
- Associations, not causes. A high value shows that your body is under load — not what caused it.
Sources
- Strüven et al., 2025, Nutrients — alcohol, nocturnal resting heart rate and sleep, with background on night-time heart rate and mortality. PMC12073130
- Li et al., 2025, Frontiers in Physiology — pre-sleep HRV predicts chronic insomnia and sleep continuity in national-level athletes. fphys.2025.1627287
- You et al., 2021, Int. J. Environ. Res. Public Health — a single slow-paced breathing session raises cardiac vagal activity. PMC8656666
Keep reading
SAYA is a wellness product, not a medical device. Nothing here is a diagnosis or medical advice — if you suspect a sleep or heart condition, please talk to a professional.
See these patterns in your own Garmin data.
SAYA is in private beta with a first group of Garmin athletes. Join the waitlist — invites go out in order.
Get early access