Your five training zones in bpm, Karvonen method
| Zone | % of reserve | ≈ % of max HR | Feels like | Trains |
|---|---|---|---|---|
| Zone 1 · Recovery | 50–60% | ~60–70% | Very easy; could sing | Warm-ups, active recovery, blood flow |
| Zone 2 · Aerobic base | 60–70% | ~70–77% | Conversational, all-day pace | Fat oxidation, endurance base, mitochondria |
| Zone 3 · Tempo | 70–80% | ~77–85% | Sentences get short | Aerobic power, race pace for long events |
| Zone 4 · Threshold | 80–90% | ~85–93% | Hard; single words | Lactate threshold, VO2 base work |
| Zone 5 · VO2 max | 90–100% | ~93–100% | Maximal; no talking | Top-end speed, VO2 max intervals |
Zone boundaries follow the widely used five-zone heart-rate-reserve model (ACSM-style intensity bands). The ≈% of max HR column assumes a typical resting rate near 60 bpm; your exact equivalents shift with your resting HR.
| Age | Classic (220 − age) | Tanaka (208 − 0.7 × age) | Zone 2 floor (60%, RHR 60) |
|---|
Both formulas carry a standard deviation of roughly 10–12 bpm versus a true measured max, so treat yours as a center, not a ceiling. Tanaka tends to fit better past age 40; the classic overestimates for younger adults.
Training by heart rate turns "run easy" into a number. The Karvonen method is the version that respects your physiology, because it keys off heart-rate reserve, the gap between your max and your resting rate, rather than a raw percentage of max that ignores how fit you already are.
HRmax = 220 − age (or Tanaka's 208 − 0.7 × age). Heart-rate reserve (HRR) = HRmax − resting HR. Zone boundaries = HRR × intensity + resting HR, with intensities 50/60/70/80/90/100% marking the edges of the five zones. Two people with the same max but different resting rates get different zones; that's the point.
Take your resting HR over three mornings and average it; one morning after bad sleep or strong coffee will skew every zone. Pick the classic formula unless you're over 40 or have reason to distrust 220 − age, in which case Tanaka is the better default. If you've ever seen your heart rate in a hard 10-minute effort or a race finish, that reading beats both formulas: choose custom and enter it.
Age 35, resting 60 bpm. HRmax = 220 − 35 = 185; reserve = 185 − 60 = 125. Zone 2 spans (125 × 0.60) + 60 = 135 bpm to (125 × 0.70) + 60 = 147.5 ≈ 148 bpm. Zone 3 tops at (125 × 0.80) + 60 = 160; Zone 4 tops at 172.5 ≈ 173; Zone 5 runs to 185. On a run, 135–148 is where full sentences live.
Age 52, resting 70 bpm. HRmax = 168; reserve = 98. Zone 2 = (98 × 0.60) + 70 = 128.8 ≈ 129 bpm up to (98 × 0.70) + 70 = 138.6 ≈ 139 bpm. Note how much lower that sits than the generic "140–155 Zone 2" charts: ignoring the higher resting rate would push this runner out of the aerobic base they're trying to build. Under Tanaka, max becomes 208 − 36.4 = 171.6 ≈ 172 and every zone shifts up about 4 bpm.
Target heart rate = (HRmax − resting HR) × intensity% + resting HR. The heart-rate reserve (HRmax minus resting) is the range your heart can actually expand into during exercise, so the formula gives more personalized zones than plain percentages of max. For a 35-year-old with a 60 bpm resting rate, Zone 2 at 60% intensity is (185 − 60) × 0.60 + 60 = 135 bpm.
Zone 2 is 60 to 70% of heart-rate reserve: the conversational, all-day-possible pace that builds aerobic base and fat oxidation. For a 35-year-old with a 60 bpm resting heart rate that's 135 to 148 bpm. You should be able to speak full sentences; if you can sing, you're drifting into Zone 1.
Measure it first thing in the morning before getting out of bed, counting your pulse for 60 seconds (or 30 seconds and doubling). Average three to five mornings. Typical adults rest between 60 and 100 bpm; regular exercisers often sit in the 50s and endurance athletes in the 40s. Caffeine, poor sleep, stress, and illness all elevate it, so ignore outlier mornings.
None of them, individually: measured max has a standard deviation of 10 to 12 bpm no matter the equation. Tanaka (208 − 0.7 × age) fits adults over 40 better than the classic 220 − age, which skews high for younger people. If you have a lab test or a hard-effort reading from a race, enter it as a custom max; real data always beats an estimate.
Yes, but it's widely misread. At Zone 2 intensity fat supplies a larger share of the fuel, but a smaller share of a bigger total; higher zones burn more absolute fat AND more total calories. The practical value of Zone 2 is that you can do lots of it, recovering quickly, which builds the machinery that burns fat at every intensity.
The polarized pattern most endurance coaches use is roughly 80% of weekly training time in Zones 1–2 and 20% in Zones 4–5, with Zone 3 used sparingly. For general health, 150 minutes of moderate (Zone 2–3) activity a week plus two strength sessions matches the physical-activity guidelines and needs no high-intensity work at all.