Get your 5 training zones — the HR ranges that separate recovery from threshold from VO₂ max. Pick the method that fits your data: max HR, Karvonen reserve (most recommended), or lactate threshold HR (most accurate).
Measure first thing in the morning, lying down, before caffeine.
Estimated max HR: 184 bpm(Tanaka formula: 208 − 0.7 × age)
Recovery
Warmup, cooldown, active recovery
120 - 132
50-60% bpm
Aerobic
Long runs, base building, fat oxidation
132 - 145
60-70% bpm
Tempo
Steady aerobic effort, marathon pace
145 - 158
70-80% bpm
Threshold
Lactate threshold, tempo intervals
158 - 171
80-90% bpm
VO₂ Max
Hard intervals, maximal efforts
171 - 184
90-100% bpm
Threshold prescribes workouts by zone — and watches you hit them
Your workouts come with zone targets. Your Apple Watch or Garmin alerts you in real time when you drift out of zone. The coach reviews the session and adjusts your plan based on what you actually held.
Try Threshold freeZones as a percentage of max HR. We use the Tanaka formula (208 − 0.7 × age) rather than the classic 220 − age, because Tanaka is measurably more accurate for athletes over 40 and across the broader population. Good default if you don't have any other data.
Zones as a percentage of heart rate reserve — the gap between your resting HR and max HR. This accounts for individual cardiovascular fitness: a fit athlete with a low RHR gets appropriately lower zone thresholds than a less-conditioned person with the same max HR.
HR = ((MHR − RHR) × %intensity) + RHR
If you know your lactate threshold HR — usually from a 30-minute all-out time trial (average HR of the last 20 minutes) — use it. Joe Friel's LTHR-anchored zones are more physiologically specific than any MHR-based method because LTHR reflects your actual metabolic crossover point, not a population-average estimate.
The classic 220 − age formula is still the most widely-cited, but it's been shown to over-estimate max HR in older adults (by up to 10 bpm at age 60+) and under-estimate in younger adults. Tanaka is based on a 2001 meta-analysis of 351 studies and has much better real-world accuracy. We use Tanaka here; your Garmin and most other modern tools do too.
Threshold prescribes every workout with a target zone. Your Watch buzzes when you drift out. The coach reviews what you held and adjusts your next session based on reality, not what you planned.
See Threshold