How the test works
Zone Work sets your heart-rate zones from one number: your threshold heart rate, roughly the highest heart rate you could hold for an hour. It finds it with a standard field test, and it uses the same test every time so each result compares with the last.
The test
30 minutes hard and steady, with 15 minutes easy before and 10 easy after (Zone Work adds those). The 30 minutes is as hard as you can hold evenly from start to finish, on your own: not a race, and not with others, which pushes your heart rate higher than you could hold alone. Do the bike and the run on separate days; each sport has its own threshold.
Your threshold is your average heart rate over the last 20 minutes. The first 10 are left out because heart rate is still climbing. This is the 30-minute test described by coach Joe Friel, and published in TrainingPeaks' guides.
You can change the times behind "Adjust times". A test of 20 to 29 minutes still gives a threshold, marked approximate: it averages what's left after the first 10 minutes. Under 20 minutes gives none, and so does a test paused for more than 30 seconds, because heart rate restarts low after a stop.
The zones
Zones follow Joe Friel's tables, which differ a little between cycling and running. Threshold is where zone 5 begins.
| Zone | Bike | Run |
|---|---|---|
| 1 | under 81% | under 85% |
| 2 | 81–89% | 85–89% |
| 3 | 90–93% | 90–94% |
| 4 | 94–99% | 95–99% |
| 5 | 100% and up | 100% and up |
Percentages are of your threshold heart rate.
How often to retest
Every four to eight weeks is common. Zone Work suggests a retest six weeks after your last one. Threshold heart rate tends to move slowly, so a change of a few beats is normal.
Before you start
The test is a hard effort. If you have a heart condition, are returning from illness or injury, or are unsure whether hard exercise is right for you, check with your doctor first.
References
- Joe Friel, Determining your LTHR and The 30-minute test is easy, really.
- TrainingPeaks, Joe Friel's quick guide to setting zones (the zone tables).
- TrainingPeaks, Thresholds 411.
Zone Work is not affiliated with or endorsed by Joe Friel or TrainingPeaks. Questions: support@zonework.app.