How Strava Calculates Your Heart Rate Zones
Strava estimates your maximum heart rate as 220 − age and draws your zones from it. If it has no age on file it assumes a maximum of 190 bpm, a number attached to nobody in particular. And unless you have set a maximum manually, your zones move every year on your birthday, without telling you.
That last part matters more than it sounds, because Strava is where most people actually look at their training.
Your watch decided, then Strava decided again
Your Garmin, COROS or Polar has its own maximum heart rate and its own zones. Strava has a separate set. The activity uploads with raw heart rate data, and Strava re-buckets it using Strava's numbers.
So a run that your watch called zone 2 can appear as zone 3 on Strava, with neither device wrong. They are two different reference numbers applied to the same data. If you have never touched Strava's settings, the reference is an age formula that carries roughly ±10 to 12 bpm of individual error and is biased high for the young and low for the old.
Maximum heart rate
185bpm
| Zone | Range | What it trains |
|---|---|---|
| Z1 | Recovery 93–111 bpm | Active recovery and warm-up; promotes blood flow without adding fatigue. Very easy, RPE 1–2. Full conversation, barely breathing hard. |
| Z2 | Endurance 111–130 bpm | Aerobic base, fat oxidation and capillary density, the bread-and-butter zone. Comfortable, RPE 3–4. Can hold full sentences. |
| Z3 | Tempo 130–148 bpm | Aerobic capacity and muscular endurance; 'moderately hard' steady work. Working, RPE 5–6. Short sentences only. |
| Z4 | Threshold 148–167 bpm | Lactate threshold, your sustainable race-pace ceiling. Hard, RPE 7–8. A few words at a time. |
| Z5 | VO₂max 167–185 bpm | Maximal aerobic power and VO₂max via short, hard intervals. Very hard to maximal, RPE 9–10. No talking. |
Z1 · Recovery. Active recovery and warm-up; promotes blood flow without adding fatigue. Very easy, RPE 1–2. Full conversation, barely breathing hard.
Z2 · Endurance. Aerobic base, fat oxidation and capillary density, the bread-and-butter zone. Comfortable, RPE 3–4. Can hold full sentences.
Z3 · Tempo. Aerobic capacity and muscular endurance; 'moderately hard' steady work. Working, RPE 5–6. Short sentences only.
Z4 · Threshold. Lactate threshold, your sustainable race-pace ceiling. Hard, RPE 7–8. A few words at a time.
Z5 · VO₂max. Maximal aerobic power and VO₂max via short, hard intervals. Very hard to maximal, RPE 9–10. No talking.
- Zones are simple percentages of maximum heart rate (Z1 50–60% up to Z5 90–100%). They are easy to set but assume your HRmax is accurate.
- Heart rate lags effort by 1–3 minutes and drifts upward in heat or dehydration ('cardiac drift'), so treat short, hard efforts by feel.
A PDF of your personalized results, with a QR code to reopen them anytime.
Work out what your zones should be from a tested maximum, then go and make Strava agree with them.
The birthday problem
Because 220 − age changes every year, Strava recalculates your zones annually unless you have set a maximum yourself. Nothing announces it. Your zone boundaries drop by one beat, your historical comparisons shift underneath you, and the "zone 2" you ran last year is a slightly different band this year.
Setting a manual maximum stops this. It also means you own the number, which is the point: a real maximum falls by about 0.7 beats a year, not a clean one, and the way to track that is to retest every couple of years rather than to let a formula guess. Gesa Krause's post covers what that decline does and does not mean.
How to take control
- Test your maximum. Build to hard over 10 to 15 minutes, finish with an all-out 60 to 90 second effort, take the highest reading off a chest strap, repeat within two weeks and keep the higher number. Not for anyone with cardiac risk or new to hard training. Protocol in finding your maximum heart rate.
- Enter it in Strava under your training zone settings, rather than leaving the age estimate.
- Edit the zone boundaries directly if you prefer a different model to Strava's default split.
- Set sport-specific zones if you subscribe. Running and cycling maximums differ by several beats, because more muscle is working when you run.
- Make your watch match. Two systems disagreeing is worse than either one being slightly off.
If you have a tested threshold heart rate, that is a better anchor than any maximum, and LTHR zones will tell you where the boundaries belong before you type them in.
FAQ
How does Strava calculate heart rate zones? From your maximum heart rate, estimated as 220 − age unless you set your own. With no age on file it defaults to 190 bpm.
Why are my Strava zones different from my Garmin zones? They use separate maximum heart rate settings. Strava re-buckets the uploaded data with its own number, so the same run gets different zone labels.
Do Strava zones update automatically? Yes. If you have not set a manual maximum, Strava recalculates on your birthday as 220 − age changes.
Can I set custom heart rate zones on Strava? Yes. Set your own maximum or edit the boundaries directly, and subscribers can keep separate zones for running and cycling.
What is Strava's default max heart rate? 220 − age, or 190 bpm if no birth date is on file.
Other brands
- Garmin uses Tanaka and auto-raises HRmax from peaks.
- COROS recommends Gellish and runs three zone models.
- Wahoo is the outlier that anchors to threshold instead.
- Apple Watch publishes no formula at all.
Sources
- Strava Help Center on heart rate zones
- Strava Help Center on training zones
- Tanaka, Monahan & Seals (2001), the 208 − 0.7 × age formula
Cover photo by Snora2020, CC BY-SA 4.0, via Wikimedia Commons.
