Heart rate zones for running: a practical guide

What zones are for

Heart rate zones are ranges of beats that correspond to different intensities of effort. They solve a practical problem: pace lies. On a hot day, uphill or when tired, the same pace demands much more from the body — and heart rate shows it right away. Training by zone is training by real effort, not by the number on the watch.

The five zones

Zone 1 (50–60% of max HR): very easy, recovery and warm-up. Zone 2 (60–70%): easy, conversational — where most of the volume should sit. Zone 3 (70–80%): moderate, the "grey zone" many people train in without meaning to. Zone 4 (80–90%): threshold, tempo-run pace. Zone 5 (90–100%): maximal, the pace of short intervals.

A well-distributed week has 75 to 80% of time in zones 1 and 2, almost nothing in zone 3, and 15 to 20% in zones 4 and 5. If your watch shows most of your time in zone 3, you're running your easy runs too fast.

How to find your max heart rate

The "220 minus age" formula is off by up to 15 beats for many people — enough to put your zones in the wrong place. Better: use the highest HR you've ever seen on the watch at the end of a race or a hard interval, or do a simple test after a thorough warm-up: 3 × 2 minutes uphill, hard, jogging back down; max HR shows at the end of the last rep. Only do this if you're healthy and used to hard workouts.

A more precise alternative for zone 2 is the talk test: the point at which saying a full sentence starts to get hard marks the top of zone 2. Note the HR at that moment and use it as the ceiling for your easy runs.

Limitations and caveats

HR takes a minute or two to respond to a change of pace, so it's no use for controlling short intervals — for those, use pace. It rises with heat, dehydration, caffeine, poor sleep and stress; an easy run with higher-than-usual HR is information, not an error. Wrist sensors misread on cold days or with a loose strap; a chest strap is more reliable.

And most importantly: zones are a tool, not an obligation. Anyone without a monitor can train very well by perceived effort — the two scales say almost the same thing.

How PaceOn helps

Every workout in the plan shows the target HR zone next to the pace range and the effort, so you can pick the reference that makes sense on the day. When you import an activity with heart rate, the system compares the average zone with the workout's purpose and comments — an easy run done in zone 3 shows up as an alert, with the explanation.