Exertion is Titan's measure of the effort you accumulate in a day, on a scale from 0 to 10. Workouts add most of it, weighted by the heart rate zones you trained in, and steps add a little on top.
01The 0 to 10 scale
Exertion appears on Today as a ring with one decimal place. Tap it to open the Exertion screen. It shows today's score with its band, your target range, workout suggestions, an Exertion history chart with 7, 30, and 60 day windows, and your heart rate across the day with workouts marked.
The score is a daily total. It climbs as workouts and steps reach Apple Health, and it stops at 10. Two parts feed it. Workout points come from heart rate recorded during your workouts. Step points come from how far you walked across the whole day. Titan adds the two and caps the sum at 10. Apple Watch rates each workout on a separate 1 to 10 effort scale, covered in Apple Watch effort ratings compared with Titan.
02Zone weights
Titan builds a raw load number from the minutes you spend in each heart rate zone during recorded workouts. Titan multiplies each minute by its zone number.
| Zone | Name | Load per minute |
|---|---|---|
| Zone 1 | Very Light | 1 |
| Zone 2 | Light | 2 |
| Zone 3 | Moderate | 3 |
| Zone 4 | Hard | 4 |
| Zone 5 | Maximum | 5 |
Thirty minutes in Zone 2 gives a load of 60. The same thirty minutes in Zone 4 gives 120. Only heart rate inside a workout counts toward load. A high heart rate during a stressful meeting adds nothing to Exertion. Your zone boundaries come from your max heart rate, and heart rate zones explains how to check and edit them.
03How load becomes workout points
Titan converts load to points on a curve that flattens as it rises. Workout points equal 10 multiplied by one minus e raised to the power of negative load divided by 100. Each extra minute of effort adds fewer points than the minute before it.
| Raw load | Example session | Workout points |
|---|---|---|
| 25 | 25 minutes in Zone 1 | 2.2 |
| 50 | 25 minutes in Zone 2 | 3.9 |
| 100 | 25 minutes in Zone 4 | 6.3 |
| 150 | 50 minutes in Zone 3 | 7.8 |
| 200 | 50 minutes in Zone 4 | 8.6 |
| 300 | 60 minutes in Zone 5 | 9.5 |
Thirty minutes in Zone 2 lifts you from nothing to 4.5. Going from 8 to 9 takes a long, hard session. Workout points approach 10 without reaching it. Steps can close the last gap, and the total stops at 10.
The same daily raw load feeds your short-term and long-term averages. See training load.
04What steps add
Steps add up to 1.2 points on any day, with or without a workout. Below 700 steps they add nothing. Between 700 and 12,000 steps the contribution rises in a straight line, so 6,350 steps adds 0.6. At 12,000 steps and above you get the full 1.2.
05Why a rest day shows 1
A day without a workout still scores 1.0 as long as you moved. Titan applies a floor of 1.0 when at least one of these is true for the day.
- You took 700 or more steps.
- You burned 90 kcal or more of active energy.
- A workout added load.
A rest day with 4,000 steps earns 0.35 step points, and the floor lifts it to 1.0. The score reads 0 only when all three are missing. That means fewer than 700 steps, under 90 kcal of active energy, and no workout. A 0 on a day you were active usually means your watch data has not reached Apple Health yet.
06Workouts without heart rate
A workout with no heart rate still counts. Titan estimates its load from duration, multiplying the workout's minutes by a factor for its activity type.
| Activity type | Examples | Load per minute |
|---|---|---|
| Endurance | Run, walk, cycle, swim, row, hike, elliptical, stairs | 1.0 |
| Mixed | HIIT | 0.95 |
| Strength | Traditional strength, functional strength, cross training | 0.9 |
| Mobility | Yoga, Mind & Body | 0.65 |
| Other with distance | Any other activity type that recorded distance | 0.95 |
| Other | Other, tennis, soccer, and every type not listed above | 0.8 |
| Sauna or steam | Other activity types without distance, when your Other label contains "sauna" or "steam" | 0.5 |
A factor of 1.0 counts each endurance minute the same as a minute in Zone 1. A 60 minute strength session without heart rate gives a load of 54, which is about 4.2 workout points.
To mark your Other workouts as sauna sessions, tap your avatar on Today to open You, then tap the Your Training tile and choose Rename Other Workout. Enter a label that contains "sauna" or "steam". For workout recording and sync, see watch-based workouts.
07Exertion bands
The label under the ring on the Exertion screen places your score in one of four bands.
| Band | Score |
|---|---|
| Low | Under 2.5 |
| Moderate | 2.5 to under 5.5 |
| High | 5.5 to under 7.5 |
| Very High | 7.5 and above |
A band describes effort alone. Whether that effort suits today depends on your training goal and Recovery, which set the range covered in exertion target.
