Calculate your personalised training zones using one of five methods — from simple age-based estimates to lactate threshold calculations.
⚠️ These are estimates only. Heart rate zones vary significantly between individuals of the same age and fitness level. Max HR formulas carry an error margin of ±10–12 bpm for many people, which can shift all five zones considerably. Use these zones as a starting point and refine them over time based on how you feel at each effort level.
About the methods
1. Karvonen (Heart Rate Reserve) — the most commonly recommended method for runners. Uses your resting HR as well as your max HR to calculate your usable heart rate range (HRR). More personalised than simple percentage because it accounts for your individual fitness level. Formula: Target HR = Resting HR + (% × (Max HR − Resting HR)).
2. Max HR percentage — the simplest method. Zones are calculated as a straight percentage of your maximum heart rate. Less accurate than Karvonen as it ignores resting HR, but quick and widely used. The 220−age max HR formula has a standard deviation of ±10–12 bpm so actual zones may differ significantly.
3. Joe Friel (lactate threshold) — used by many triathlon and endurance coaches. Zones are based on your lactate threshold heart rate (LTHR) — the HR at which lactate begins to accumulate faster than it can be cleared. This removes the uncertainty of max HR estimation entirely. To find your LTHR, run a flat 30-minute time trial at maximum sustainable effort and record your average HR for the final 20 minutes.
4. Garmin / Polar 5-zone — the zone model used by most sports watches. Based on simple max HR percentages but with slightly different zone boundaries to the standard model. Useful if you want your zones to match what your watch displays.
5. Maffetone (MAF method) — developed by Dr Phil Maffetone, used widely in ultra-endurance and barefoot running communities. Focuses entirely on aerobic base building. Your MAF heart rate = 180 − age (with adjustments for training history and health). All easy running is done at or below this number. The philosophy aligns closely with OYF — build a huge aerobic base at low intensity before adding speed work.
How to find your true max HR:
The 220−age formula is an estimate only. More accurate approaches: run hard up a steep hill for 2–3 minutes at maximum effort and note your peak HR; use the highest HR recorded during a recent all-out race effort; or complete a formal max HR test on a treadmill with progressive intensity increases. Your highest recorded HR during any hard effort is a reliable lower bound.
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