Heart rate training zones
Max HR, zones 1 to 5, heart rate reserve: how to calculate and use your training heart rate zones.
Estimating your maximum heart rate (max HR)
Max HR ≈ 220 − age
An approximate formula (Fox), simple but imprecise for some individuals — a supervised exercise test gives a more reliable figure.
The 5 training zones (% of max HR)
| Zone | % max HR | Feels like | Goal |
|---|---|---|---|
| Zone 1 | 50-60% | Very easy | Recovery |
| Zone 2 | 60-70% | Easy, can hold a conversation | Base endurance |
| Zone 3 | 70-80% | Moderate | Aerobic endurance |
| Zone 4 | 80-90% | Hard | Threshold |
| Zone 5 | 90-100% | Maximal | Power, sprint |
Most endurance training (often 70-80% of total volume) happens in zone 2, not zone 4-5 — counter-intuitive, but it's the basis of most polarised training methods.
Heart rate reserve (Karvonen method)
More precise than a plain %max HR, it accounts for resting heart rate (resting HR):
Target HR = ((max HR − resting HR) × %intensity) + resting HR
Example: age 30 (max HR ≈ 190), resting HR = 60, target at 70% intensity → ((190−60) × 0.70) + 60 = 151 bpm.
Measuring your resting heart rate
Ideally in the morning, right after waking, before getting up: taking your pulse over 60 seconds (or 15 seconds × 4) across several days and averaging gives a more reliable figure than a single measurement. A low resting HR (in a trained athlete, sometimes under 50 bpm) generally reflects good cardiovascular fitness.
Measured vs. estimated max HR
| Method | Reliability |
|---|---|
| 220 − age formula | Approximate, ±10-12 beat margin of error depending on the individual |
| Tanaka formula (208 − 0.7 × age) | Slightly more accurate for older adults |
| Supervised exercise test | The most reliable, measures the actual value rather than an estimate |
A maximal exercise test carries risks and should be supervised by a professional, especially with a known or suspected cardiovascular condition.
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