SomviaThe four parts
A recovery score is not a measurement of anything. It is a summary of four things your devices measured while you were asleep or resting, put on one scale so they can be read in a second:
- Overnight heart rate variability. The night's HRV against what your own nights usually look like.
- Resting heart rate. Same comparison, opposite direction: above your usual is the unfavourable side.
- Sleep. How long you slept and how broken the night was.
- Recent training load. What you have asked of yourself in the last few days, so a hard Saturday still counts on Sunday morning.
Somvia computes this on your iPhone from data already in Apple Health, and every part is visible: open the score and each line says what it was, what your usual is, and which side of it you are on.
Other recovery apps read a different set. Athlytic uses overnight HRV and resting heart rate, and Bevel adds wrist temperature, respiratory rate and blood oxygen. Five recovery apps compared lists what each one reads.
Why the baseline is yours, not a population's
An HRV of 44 ms means nothing on its own. It can be an excellent night for one person and a poor one for another, and the same person's numbers move with age, season and stress. What carries information is the distance between last night and your own recent nights.
The score compares your readings with a rolling baseline built from your own history. Existing Apple Health records count toward that history. A new installation can therefore show results without waiting to collect every night again, if enough suitable records are already available.
Recovery, sleep and HRV status have different data requirements. Recovery needs valid overnight readings and personal comparisons. Sleep duration can use a recorded night, while bedtime and sleep-stage comparisons need more history. HRV status compares recent nights with a longer reference period. The app shows which records are missing.
What Apple Health has to contain
| Reading | Written by | Without it |
|---|---|---|
| Overnight HRV | Apple Watch worn overnight, or another wearable that writes HRV to Apple Health | No recovery score and no HRV status |
| Resting heart rate | Apple Watch, or a device that writes a daily resting figure | Recovery loses one of its parts |
| Sleep | Any app or device that writes sleep to Apple Health | No sleep score |
| Workouts | Any workout in Apple Health, whoever recorded it | Load is not counted |
Somvia reports what Apple Health contains and never invents a measurement that is not there. If your watch spent the night on the charger, the morning has no recovery score, and it says so rather than carrying yesterday's forward.
Reading a low score
A low score is a description, not an instruction. It says the night's numbers sat below your usual, which happens after a hard session, a short night, alcohol, illness, travel or a stressful week. Two useful habits:
- Read the parts, not just the number. HRV low with resting heart rate normal after a hard Saturday reads differently from both moving together for four days.
- Read the run of days. One night below your usual is noise. Four in a row is a pattern, and Somvia raises it as an alert when it sees one.
Connected over MCP, the same numbers are readable by an AI Agent, so you can ask why the score moved and get an answer built from your own nights rather than from a general article.
Where the method comes from
The four parts, the baseline window and the way they are weighted follow the published sport-science literature on heart-rate variability monitoring and training load. The models Somvia uses, and what each one needs, are listed on how the scores work.
Questions
Do I need an Apple Watch for a recovery score?
You need a wearable that writes overnight heart rate, HRV and sleep to Apple Health. Apple Watch does this; some third-party wearables write sleep but not HRV, and in that case the recovery score cannot be estimated. Training load, session detail and training status work from any workout in Apple Health.
Why is my recovery score missing this morning?
Because the night has no record. Somvia reads what Apple Health contains and does not carry a previous day forward or fill a gap with an estimate. If the watch was off the wrist or the sleep was not recorded, the morning has no score.
How is this different from Apple's own Health app?
Apple Health stores the measurements. It does not combine overnight HRV, resting heart rate, sleep and recent training load into one daily reading, and it does not compare them against your own rolling baseline. That is what Somvia adds.
Is a recovery score a medical measurement?
No. It is an estimate built from consumer-wearable data, useful for training decisions and nothing more. Somvia is not a medical device and does not provide medical advice, diagnosis or treatment.