Heart rate zones explained
Heart rate zones split your effort into five bands, from an easy spin to an all-out sprint. Here is what each zone means, how the bands are set, and how to train with them.
What heart rate zones are
A heart rate zone is a range of beats per minute that matches a level of effort. Most systems split your range into five bands, each defined as a percentage of your maximum heart rate. Staying in a chosen zone lets you train at the effort you planned, instead of guessing.
Zones work because heart rate follows effort: the harder your muscles work, the more oxygen they need, and the faster your heart beats to deliver it. Heart rate also reacts to heat, sleep, caffeine, stress and fatigue, so treat it as a guide, not a verdict.
The five zones
These are the bands Motionry uses. They start at 60, 70, 80 and 90% of your max heart rate.
| Zone | % of max | Feels like | Used for |
|---|---|---|---|
| Z1 Recovery | Under 60% | Very easy. You can chat without thinking. | Warm-ups, cool-downs and rest days |
| Z2 Endurance | 60 to 70% | Easy. Full sentences. | Long, steady sessions that build your aerobic base |
| Z3 Tempo | 70 to 80% | Comfortably hard. Shorter sentences. | Steady work you can sustain for a while |
| Z4 Threshold | 80 to 90% | Hard. A few words at a time. | Intervals near the effort you could hold for about 20 minutes |
| Z5 Max | 90% and up | Very hard. Talking is a struggle. | Short sprints, under a minute |
The “feels like” column follows the talk test, a rough guide that varies from person to person. Other systems use three, six or seven zones, or base them on power or pace, and draw the lines in slightly different places.
Where the numbers come from
Everything starts with your max heart rate, the highest rate your heart can reach in an all-out effort. You can measure it or estimate it from your age. If it is 10 beats off, every zone is 10 beats off too. Our guide to max heart rate formulas covers how accurate each estimate is, and the heart rate zone calculator does the maths for you.
Two other approaches are common. Heart rate reserve, the Karvonen method, sets each zone as a share of the gap between your resting and max heart rate. Some coaches base zones on lactate threshold heart rate instead of max, which suits athletes who have tested it.
Using zones in training
- Keep most sessions easy. A common rule of thumb in endurance coaching is about 80% of training time at easy effort, in Zones 1 and 2, and about 20% hard. Many recreational athletes drift into the middle and train too hard on easy days.
- Make hard days count. Zones 4 and 5 are demanding. Use them for planned intervals, and leave time to recover afterwards.
- Use zones for steady efforts. Heart rate takes a minute or so to catch up with a change in effort, so it suits long, steady sessions better than short intervals. For those, pace, power or how hard it feels is a better guide.
- Watch the trend. The same easy pace at a lower heart rate over a few weeks is a good sign. One high reading on a hot day is not a problem.
When heart rate misleads
Heat, dehydration, poor sleep, illness, caffeine, stress and altitude can all push heart rate up at the same effort. Some medications, including beta blockers, hold it down. Wrist sensors can also lag or misread during hard intervals, where a chest strap is more reliable. When the number and the feeling disagree, trust the feeling and look for the cause.
This guide is general fitness information, not medical advice. If you have a heart condition, take medication that affects your heart rate, or are unsure whether hard exercise is safe for you, talk to a doctor first.
Zones in Motionry
Motionry sets your five zones from your age or from a max you enter. It then fills the screen with your zone colour as your heart rate arrives from an Apple Watch or a Bluetooth chest strap. Rides, runs and walks share the same zones. See how it works for Zone 2 training.