Today shows four vitals from Apple Health, each on its own tile, and a tap on any tile opens the Vitals screen with their history. This article explains what each number means, how the latest day, baseline, and shaded range differ, and which readings depend on how your watch is set up.
01The four readings
The tiles show HRV in milliseconds, RHR for resting heart rate in beats per minute, RR for respiratory rate in breaths per minute, and SpO₂ for blood oxygen as a percentage. All four show as whole numbers on Today.
HRV is the average of the HRV readings Apple Health recorded during last night's sleep. Without a sleep session, Titan uses your HRV average over the past 24 hours, then your most recent HRV reading. Resting heart rate is today's resting heart rate from Apple Health. If today has none, Titan uses your average over the last 3 days, then the last 7 days. Respiratory rate and blood oxygen are the most recent samples in Apple Health.
Under each value, a status word compares the reading with your range over the last 30 days. Usual means the reading falls inside that range. Above and Below mean it falls outside it. The bar on the side of the tile draws the range as a band with a dot for the reading. Green marks a reading inside the range or on the better side of it, such as HRV above its range or resting heart rate below it. Red marks the other side. Respiratory rate turns red on either side. Until Titan has enough days to set a range, the tile reads Range needs more days.
02Latest day, baseline, and shaded range
The Vitals screen opens at the vital you tapped. A period picker with 7 Days, 30 Days, 60 Days, and 6 Months sits at the top, and it starts on 30 Days. Under it, four tiles repeat your most recent value for each vital with its status for the selected period. Tap a tile to jump to that vital's section.
Each section has three numbers and a chart.
| Label | What it shows |
|---|---|
| Latest day | Your most recent reading in the period |
| 30-day baseline | The median of your daily values across the period. The label follows the period you pick |
| Change | Latest day minus baseline |
If your most recent reading is from an earlier day, the Latest day label shows that date instead.
For HRV, resting heart rate, and respiratory rate, the shaded band on the chart covers the 20th to 80th percentile of your daily values in the period. That is the middle 60% of your days. The line under the chart names your status, such as Within usual range, followed by the low and high ends of the range.
Titan sets the baseline and range only when the period has at least 7 days with readings and those readings cover at least 60% of its days. A 7-day period therefore needs a reading on all 7 days. If HRV, resting heart rate, or respiratory rate falls short, its section reads Range needs more days. When some days in the period have no reading, a line such as "4 days missing" appears under the chart. A section with no readings at all reads No readings in this period.
03The blood oxygen chart
Blood oxygen uses a fixed scale in place of your personal band. The chart shades a Normal band from 95 to 100% and plots each day as a dot. Days below 95% turn red. A dashed line marks your baseline for the period. The chart gives the 95 to 100% range most of its height, so small changes inside the normal range stay visible.
04The range is personal
For HRV, resting heart rate, and respiratory rate, the band describes your own history. It is not a clinical reference range. A reading outside it means the value is unusual for you in that period. It does not diagnose a condition.
The range moves when you change the period. A 7 Days range reflects last week. A 6 Months range reflects half a year, so one hard week barely shifts it.
05How Vitals differs from the Recovery baseline
Recovery keeps its own baselines for overnight HRV and sleeping heart rate. They are the median of your measured nights within the Recovery window, which defaults to 60 nights. The Vitals period picker has no effect on Recovery, and the Recovery window has no effect on the Vitals baseline or range. The two numbers can differ on the same day because they measure different things over different days. See personal baselines and how the Recovery score works for the Recovery side.
06Add a reading by hand
Tap Add Reading at the top of the Vitals screen to log a measurement you took yourself, such as a reading from a pulse oximeter. The sheet opens on the vital in view. Tap its title to switch between HRV, Resting Heart Rate, Respiratory Rate, Blood Oxygen, and Weight. Enter the value, set the time, and tap Save. The sheet shows your last reading from Apple Health for comparison.
Titan writes the reading to Apple Health, marked as entered by hand, and the chart updates with it. If Titan can't write that type, the sheet says so. Allow it in Settings > Health > Data Access & Devices > Titan on your iPhone, then try again.
07Readings that depend on settings
Use RMSSD for HRV switches every HRV value on the tiles and charts from SDNN, Apple's default, to RMSSD. It sits under Settings > Recovery & Sleep. Reach Settings from the avatar on Today, then You > Settings.
Respiratory rate and blood oxygen come from your watch. Apple Watch records respiratory rate while it tracks your sleep, so you need to wear it to bed with sleep tracking on. Blood oxygen needs the Blood Oxygen measurement turned on in the Watch app on iPhone, and only some Apple Watch models measure it.
A gap in a chart means Apple Health had no reading for that day. Check that the reading exists in the Health app and that Titan has read access. For missing HRV, see HRV not showing. For watch setup, see Apple Watch support.
