Training Zones Calculator — Heart Rate, Pace and Power
Training zones are the backbone of structured endurance planning. They translate "easy", "tempo" and "hard" into measurable ranges — in heart rate, pace, or power. Athletes who train in the right zones build form deliberately. Athletes stuck in the grey middle ground between Z2 and Z4 accumulate training hours without much to show for it.
Use the calculator below to get your zones for running, cycling and swimming in seconds. Then we'll explain where the models come from, which method fits which sport — and where the most common pitfalls hide.
Why training zones?
Most hobby athletes train by feel — which on long sessions tends to be too fast and on hard sessions too slow. The result: too much time in the middle intensity (often called "tempo" or "junk miles") that creates a lot of stress with little adaptation.
Zones give you a tool to control that intensity distribution. They enable what sports scientists call polarized training: 70-80% of time very easy (Z1-Z2), 10-20% very hard (Z4-Z5), little in the middle. This distribution isn't a marketing slogan — it's been documented consistently in world-class endurance athletes for two decades.
Threshold: where the foundation comes from
Every zone model is built on a threshold value — an intensity you can sustain for about an hour before physiology breaks down. Depending on discipline and method, this threshold goes by different names:
- FTP (Functional Threshold Power) — cycling with a power meter, in watts
- LTHR (Lactate Threshold Heart Rate) — HR at threshold, in bpm
- Threshold Pace — running speed, in min/km or min/mile
- CSS (Critical Swim Speed) — swim speed, in min/100m
How to determine these values is a story of its own — see our articles on FTP testing and lactate threshold without a lab. Here we assume you already know your threshold.
Threshold is not your maximum heart rate or your 5-minute power. It's the highest sustained value you can hold for an hour under race conditions. Deriving zones from max values (the typical sportwatch default like "220 minus age") almost always produces inflated numbers — and then training that's too hard.
The models, compared
Coggan (cycling, power)
The de facto standard for power-based cycling, published by Andrew Coggan in 2003. Seven zones, defined as a percentage of FTP:
| Zone | % FTP | Character |
|---|---|---|
| Z1 Active Recovery | <55% | Very easy, active recovery |
| Z2 Endurance | 56-75% | Aerobic base training |
| Z3 Tempo | 76-90% | Sweet spot, "comfortably hard" |
| Z4 Threshold | 91-105% | Threshold work |
| Z5 VO2max | 106-120% | Intervals 3-8 min |
| Z6 Anaerobic | 121-150% | Short hard intervals 30s-3 min |
| Z7 Neuromuscular | >150% | Sprints, accelerations |
Friel (all sports, HR and pace)
Joe Friel's "Training Bible" established a model based on lactate threshold heart rate (LTHR) or threshold pace. The zones are tighter than Coggan's power zones, because HR and pace respond more slowly than power.
Friel uses slightly different LTHR percentages for cycling and running — running tends to run at higher LTHR percentages because the mechanics differ. The calculator above accounts for that automatically.
Daniels VDOT (running, pace)
Jack Daniels' VDOT system derives training zones from a race performance rather than a threshold test. You enter a known PR (5k, 10k, HM, Marathon) and get back "Easy Pace", "Marathon Pace", "Threshold Pace", "Interval Pace" and "Repetition Pace".
Pro: no separate test required. Con: assumes your race performance is current and well-paced. In the calculator above you can use Daniels pace as an alternative to classic threshold pace.
CSS (swimming)
Critical Swim Speed, developed by Wakayoshi, is the standard in triathlon. CSS corresponds to sustainable threshold swim speed. You determine it from a 400m and a 200m time trial:
The calculator above does that conversion automatically and gives you swim zones as pace per 100m.
HR vs. pace vs. power — which method for whom?
This question determines which zones you can sensibly use at all. The short version:
- Cycling with a power meter: always power. Power is the only metric that reflects your actual mechanical output in real time — no lag, no interference from heat, hydration, or wind.
- Cycling without a power meter: HR. Pace is practically useless on the bike because of wind, gradient and traffic.
- Running, flat courses: pace is more precise than HR, because HR lags (up to 2-3 minutes during intervals).
- Running, hilly or long distance: HR, because pace fluctuates dramatically with terrain and cumulative fatigue.
- Swimming: pace via CSS. HR is hard to measure underwater and is heavily distorted by the dive reflex.
Pros often use multiple in parallel
A classic bike threshold workout: power as the primary anchor (e.g. 4×8 min at 95-100% FTP), HR as a sanity check (should reach Z4 by the end of each interval), pace/speed ignored. Long run, opposite approach: HR cap as the limit ("never above Z2"), pace secondary, actual speed allowed to drift with fatigue.
Common mistakes when calculating zones
1. Wrong threshold value
By far the most common error. If your FTP estimate is 15% too high, every zone shifts — your planned Z2 session actually happens in Z3. Cumulative load goes up, recovery suffers, and long-term progression stalls.
2. Max HR from "220 minus age"
This formula has a standard deviation of about ±12 bpm. A 40-year-old with a "real" max HR of 195 gets 180 from the formula — an error that shifts every HR zone down by roughly one zone. If your sportwatch auto-calculated zones from a 220-minus-age max HR, don't trust them.
3. Pace zones on hilly courses
Pace is linear — but running uphill is exponentially harder. A "tempo pace" of 4:30/km becomes physiologically Z5 at 5% gradient, even if you hold the pace. On undulating terrain, always anchor on HR and treat pace as informational.
4. Zones from old fitness
Your threshold changes with training. An athlete who tested FTP at 220 W in spring and is still riding those zones in summer is training to outdated values — usually too easy, sometimes too hard. Rule of thumb: retest every 6-8 weeks, or at least review the assumption.
5. Zone creep
If you run Z2 every day and consistently drift to the upper end (or just over), the load sneaks up. Discipline yourself to stay in the lower half of the zone — this is the core of Friel's doctrine and the reason elite coaches insist on a HR cap.
For long Z2 sessions, set an HR cap on your watch (e.g. alert at LTHR × 0.85) and accept that you'll slow down when it's hot or you're tired. That's not failure — that's exactly the point of zone-based training.
How you use zones in practice
Three concrete use cases:
- Training planning: every session has a target zone. "60 min Z2" is a clear instruction — stay between 134 and 152 bpm. Without zones it becomes "60 min easy run", which ten different athletes would execute at ten different intensities.
- Post-session analysis: time-in-zone distribution tells you whether what you actually did matches what you planned. Was that long run really Z2 or did you spend 75% of it in Z3?
- Weekly polarization: look at total weekly time in Z1-2 vs. Z4-5. If more than 25-30% sits in Z3, your training is too "grey" and won't produce peak form long-term.
Yama does this automatically
In Yama you enter your thresholds once — or let them be estimated automatically from your Strava data. Every workout is mapped to your current zones, the weekly time-in-zone distribution is computed, and a polarization index is displayed. Plus: plans export in your personal zones.
Try Yama freeBottom line
Training zones aren't an end in themselves — they're a tool that turns vague "training feel" into reproducible control. What matters isn't picking the perfect model, but using one model consistently, keeping your thresholds current, and being honest enough to actually go easy on easy days.
The calculator above covers the most important models. If you want to dive deeper, read our articles on lactate threshold testing and the FTP test.