Titan sorts your heart rate into five zones, each a band of percentages of your max heart rate. Titan can set that max from your Apple Health data, or you can enter your own and adjust where each zone starts. Time in each zone appears on Today and in Trends.
01Where the settings live
Open Settings from the avatar on Today, then You > Settings. Tap Training & Heart Rate. The Your Training tile on You opens the same screen. The Heart Rate section holds the Use Custom Max Heart Rate toggle, the Max Heart Rate value, the Heart Rate Zones editor, and a summary of each zone in bpm.
02How Titan sets your max heart rate
With Use Custom Max Heart Rate off, Titan compares two numbers. The first is the highest heart rate recorded in Apple Health over the last 30 days. The second is 220 minus your age, with your age taken from the date of birth in Apple Health. Titan uses whichever is higher. The age estimate works as a floor, so a quiet month with no hard efforts does not drag your zones down. If only one of the two numbers exists, Titan uses that one.
Turn on Use Custom Max Heart Rate to set the value yourself. The stepper moves in 1 bpm steps from 80 to 240 and starts at 180. Titan uses a custom max for your zone boundaries and for training load metrics.
Titan keeps the resolved max and your zone thresholds for up to seven days. It recalculates right away when you change the custom max or edit a zone.
03Default zones
Each zone starts at a set percentage of your max and runs up to 1% below the start of the next zone. Zone 5 runs to 100%. The example column uses a max of 190 bpm.
| Zone | Name | Default range | Example at 190 bpm max |
|---|---|---|---|
| 1 | Very Light | 53% to 73% | up to 139 bpm |
| 2 | Light | 74% to 80% | 140 to 152 bpm |
| 3 | Moderate | 81% to 86% | 153 to 163 bpm |
| 4 | Hard | 87% to 92% | 164 to 175 bpm |
| 5 | Maximum | 93% to 100% | 176 to 190 bpm |
Titan rounds each boundary to the nearest whole bpm. Heart rate below the Zone 1 start still counts as Zone 1, so every reading lands in one of the five zones. Anything above the top of Zone 4 counts as Zone 5, including readings above your max.
04Editing your zones
Go to Settings > Training & Heart Rate > Heart Rate Zones. Each row shows the zone percent and bpm range, with a stepper that moves its start 1% at a time. Each zone must start at least 1% above the zone before it, and Zone 1 cannot start below 1%. Raising one zone pushes later zones up when needed to keep that order. Tap the checkmark to save. Titan rebuilds the bpm thresholds from your max as soon as you save.
05Fallback zones
If Titan cannot work out a max heart rate, it uses fixed thresholds. That happens when custom max is off, Apple Health has no heart rate from the last 30 days, and no date of birth is set.
| Zone | Fallback range |
|---|---|
| 1 | up to 132 bpm |
| 2 | 133 to 145 bpm |
| 3 | 146 to 156 bpm |
| 4 | 157 to 167 bpm |
| 5 | 168 bpm and above |
Adding a date of birth in Apple Health, or turning on a custom max, moves you back to percentage-based zones.
06The Heart Rate Zones Updated card
When your saved thresholds change, a Heart Rate Zones Updated card appears on Today with the date of the change. A new 30-day max, an edit in the zone editor, or a change to your custom max can all trigger it. Tap the card to see why the zones changed and a table of the previous and new upper threshold for each zone in bpm. The sheet gives one of two reasons. Either Titan recalculated from your max heart rate and zone percentages, or it could not compute a fresh max and reset to the fallback thresholds. Tap Update Zones to accept the change and clear the card.
07How zone time is counted
The Heart Rate Zones card on Today shows minutes per zone for the selected day. Tap it for the detail screen, which splits time into workouts and time outside workouts.
For each workout, Titan reads the heart rate samples recorded during the session. If the samples linked to a workout cover less than 70% of its duration, Titan also reads samples between the workout's start and end times. Tap a zone to see which workouts added time to it. Tap a workout to open its detail screen, which shows the same zone breakdown for that session. See workouts for the rest of that screen.
For time outside workouts, Titan reads your heart rate for the day in 5-minute intervals. Each reading counts toward its zone until the next reading, up to 5 minutes. A longer gap adds no time, because a missing sample cannot show which zone you were in. Titan subtracts any part of an interval that overlaps a workout. The detail screen labels each zone's share as a percentage of recorded time, not of the whole day.
08Weekly Cardio Load leaves out Zone 1
On Trends, open the Training group and scroll to Cardio distribution. It charts daily minutes in Zones 2 through 5 and a Weekly totals bar chart for the same zones. Both charts leave out Zone 1. Choose Grouped or Stacked bars under Settings > App Preferences > Appearance > Trends Weekly Cardio Load Chart.
Your daily effort and longer-term load are covered in Exertion score and training load. Questions about your zones can go through the contact page.
