Zones based on thresholds
Zones based on thresholds hang on your athlete's thresholds instead of fixed numbers. After a new test you only update the thresholds, and every zone moves along. No more typing seven zones again after each test.
Fixed values or thresholds
In the window of a zone set you choose how to fill in the bounds:
- Fixed values: each zone gets a lower and an upper bound in bpm, watt or km/h. When the athlete changes, you update every zone.
- Based on thresholds: tick Based on thresholds. The columns become % From and % To, and each bound is a percentage of a threshold you fill in at the bottom.
What a bound hangs on
Next to each percentage you choose in the dropdown what that bound hangs on:
| Choice | Meaning |
|---|---|
| Ana | Percentage of the anaerobic threshold (lactate threshold or FTP) |
| Aer | Percentage of the aerobic threshold |
| VO2 | Percentage of VO2max |
| CP or CS | Percentage of Critical Power (power) or Critical Speed (speed), see Zones on Critical Power |
| 0 | The zone starts at 0. Useful for the lower bound of your first zone |
| ∞ | Open end. Useful for the upper bound of your last zone |
| Start or end value of the previous step | Takes the bound of the zone above, optionally minus or plus 1 (1 bpm or watt, 0.1 km/h). Zones line up without repeating the number |
You can mix these choices within one zone set. For example, put your recovery and endurance zones on the aerobic threshold and your intensive zones on the anaerobic threshold. While you type, you see right away which values follow.
Which thresholds you fill in
The bottom of the window holds the thresholds for the type of the zone set:
- Aerobic threshold and Anaerobic threshold are required for zones based on thresholds.
- VO2max and Max. may stay empty. Coachbox then works them out from the anaerobic threshold and shows that value in grey in the field.
If you leave the aerobic threshold empty while a CP is filled in, Coachbox works that one out from the anaerobic threshold too.
Zones on Critical Power
Limited access
Zones on Critical Power belong to the Metabolic Performance Profile test and are enabled per team by Coachbox. Want to start using them? Let us know at support@coachbox.app.
Critical Power (CP) is the highest power an athlete can sustain for a long time without tiring out. W' is the amount of work the athlete can still do above it. For running they are called Critical Speed (CS) and D'.
A zone set for power or speed has two extra fields next to the other thresholds:
- CP or CS: you fill it in yourself, or a test fills it in. Zones set to CP are a percentage of this value.
- W' (in kJ) or D' (in metres): kept with the zones and shown in the overview. Nothing calculates with it yet.
CP and the anaerobic threshold complement each other:
- Leave the anaerobic threshold empty and CP counts as the anaerobic threshold. The stress score, workouts as a percentage of FTP and the FTP in your exports to Garmin, Zwift or Coros keep working.
- Leave CP empty and zones on CP use the anaerobic threshold.
From a Metabolic Performance Profile test
When you export the zones of a Metabolic Performance Profile test, Coachbox fills in CP and W' (or CS and D') with the values of that test, and the zone set gets the Lab test label. The zones then hang on the thresholds of the test: the lower three on the aerobic threshold, from intensive endurance up on CP. If you adjust CP later, the upper zones move along.
The mobile app shows CP and W' with the zones, but you edit a zone set with CP on the web.
Good to know
- Zones are kept with the date from which they apply. A new zone set after a test changes nothing about earlier workouts, see Setting up training zones.
- A template keeps the percentages and the choice per bound, but no thresholds. Those belong to each athlete.
- Hashtags and exportable segments always use the worked-out values, also for zones based on thresholds.