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
Tap your avatar on Today to open You, then tap the Your Training tile. 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.
With the toggle off, the Max Heart Rate row shows the value Titan resolved and cannot be edited. 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
On Your Training, tap Heart Rate Zones. Each row shows the zone's percent range 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 shows "Using default zones until a new max heart rate". Titan already uses the new zones when the card appears. Tap Update Zones to close the sheet and remove the card from Today.
07How zone time is counted
The Heart Rate Zones card on Today shows your workout time in each zone for the selected day. A day without workouts shows "No workouts yet". Tap the card to open the Heart Rate Zones screen. A bar splits your workout zone time by zone, and each zone with time gets its own row.
Tap a zone to see its bpm range, its share of your workout zone time that day, and the workouts that 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. The screen also lists the day's workouts and steps, and your energy for the day.
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. Heart rate outside workouts does not count toward zone time.
08Cardio distribution leaves out Zone 1
On Trends, the Cardio distribution chart stacks your weekly minutes in Zones 2 through 5, one bar per week. It leaves out Zone 1.
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.
