Modern training is zone-based. Whether you run, cycle, row or just want to make cardio feel intentional, learning the five heart-rate zones turns "go hard" into a system you can actually plan and recover from. This guide explains what each zone is, how to calculate it for your age and fitness, and how to put them together in a week.
Quick Answer
- Max Heart Rate (HRmax) is the ceiling. The Tanaka formula —
208 − 0.7 × age— is more accurate than the classic 220 − age. - Zones are percentages of HRmax (or of heart-rate reserve, HRR, if you know your resting HR).
- Most weekly volume should sit in Zones 1–2 (easy aerobic). Hard work in Zones 4–5 is the spice, not the meal.
Get your personalised zones in seconds with our Heart Rate Zone Calculator.
Max Heart Rate: Two Formulas
The textbook 220 − age overestimates HRmax for younger adults and underestimates it for older ones. The Tanaka equation is the modern default:
HRmax (bpm) ≈ 208 − (0.7 × age)
Age 30 → ~187 bpm. Age 50 → ~173 bpm.
Both formulas are population averages. Your actual max can be 5–10 bpm higher or lower. If you have a tested max from an all-out effort, use that.
%HRmax vs. Karvonen (Heart Rate Reserve)
Two methods translate HRmax into zones.
%HRmax — Simple
Target HR = HRmax × intensity %. No resting HR needed. Easy to compute, slightly less personalised.
Karvonen — More Personalised
Target HR = (HRmax − HRrest) × intensity % + HRrest
Karvonen accounts for fitness: fitter people have lower resting HRs, so the gap between rest and max is wider — and so are the absolute bpm windows for each zone.
If you've ever measured your resting HR (first thing in the morning, 60 seconds before getting out of bed), use Karvonen. Otherwise %HRmax works fine.
The Five Zones
The standard five-zone model maps to training purposes most coaches share.
| Zone | % HRmax | What it feels like | Training purpose | |---|---|---|---| | Z1 — Recovery | 50–60% | Easy chat, "could go for hours" | Warm-up, cool-down, active recovery | | Z2 — Endurance | 60–70% | Comfortable, conversational | Aerobic base, fat oxidation, capillary growth | | Z3 — Aerobic | 70–80% | Steady but talking gets clipped | Aerobic stamina, "tempo" work | | Z4 — Threshold | 80–90% | Hard, short phrases only | Lactate threshold, race pace | | Z5 — Max | 90–100% | All-out, can barely speak | VO₂max, top-end power |
A 30-year-old (HRmax ≈ 187):
- Z1 ≈ 94–112 bpm
- Z2 ≈ 112–131 bpm
- Z3 ≈ 131–149 bpm
- Z4 ≈ 149–168 bpm
- Z5 ≈ 168–187 bpm
Our calculator does this with both %HRmax and Karvonen.
How to Use Zones in a Week
The most-supported approach for endurance is polarised or pyramidal training:
- ~70–80% of weekly volume in Zones 1–2 (easy)
- ~10–15% in Zone 3 (steady tempo)
- ~10–20% in Zones 4–5 (hard)
For a 5-hour-per-week runner, that might look like:
- 3 easy runs of 45–60 minutes in Z1–Z2
- 1 tempo run with 20 minutes of Z3 sandwiched in easy
- 1 interval session — 5 × 3 min Z4 with full recoveries
Easy days are the spine. Hard days are the spike. Skipping the easy days is the most common mistake in amateur cardio plans.
Why Zone 2 Gets So Much Attention
Zone 2 is the sweet spot where:
- Mitochondrial density improves — more energy machinery in your muscles
- Fat oxidation peaks — you spare glycogen for harder efforts
- Aerobic enzymes ramp up — your "base" gets thicker
You can do a lot of Z2 without breaking down. It is the volume that makes Z4/Z5 work productive instead of injurious. Even strength athletes benefit from 1–2 Z2 sessions per week for general health and recovery capacity.
Watches, Chest Straps and Reality
Wrist-based optical sensors are getting better but still drift in cold weather, with tattoos, and during high-intensity intervals where blood flow shifts. Chest straps are noticeably more accurate for true zone work. If you train by HR, the strap is worth it.
Two practical pointers:
- HR lags effort. When you start running, HR climbs over 30–60 seconds. Don't speed up just because HR is "still in Z2" at the first minute.
- Cardiac drift. Long sessions push HR up at the same pace; that's normal. Slow down a little to stay in your zone, or use perceived effort as the second anchor.
Sample Weeks by Goal
A few weekly templates to make the volume distribution concrete.
Fat-loss focus, 5 hours/week
- 3 × 50 min Z1–Z2 walking, cycling or jogging
- 1 × 40 min Z3 tempo bike
- 1 × 30 min Z4 intervals (e.g., 6 × 3 min hard / 2 min easy)
Running 5K to 10K progression, 5 hours/week
- 4 easy runs 45–60 min in Z1–Z2
- 1 interval session 5 × 800 m at Z4 pace
- One day off, one day strength training
Cyclist building threshold, 7 hours/week
- 3 endurance rides 90 min in Z2
- 1 sweet-spot session 2 × 20 min at upper-Z3
- 1 short Z5 session 5 × 1 min max with 4 min easy
The exact intervals can flex. The shape — lots of easy, a little of hard — does not.
Sport-Specific Zone Differences
Heart-rate zones aren't fully portable between sports. The same person typically shows:
- Running — highest HRmax of all common sports
- Cycling — usually 5–10 bpm lower HRmax than running
- Rowing — between cycling and running
- Swimming — often 10–15 bpm lower than running due to horizontal posture and water cooling
Practical rule: test or estimate HRmax per sport, especially if you train in multiple disciplines. Carrying your run zones to the bike will under-shoot training intensity.
Lactate Threshold vs. Heart Rate Zones
For serious endurance athletes, lactate threshold (LT) pace or HR is the most informative single number — more so than HRmax-derived zones.
- LT often sits at Zone 4 / threshold pace
- A 20-minute time trial average HR approximates functional threshold HR
- Anchoring zones from LT instead of HRmax produces more precise interval targets
For most recreational athletes, the Tanaka HRmax + Karvonen zone approach is plenty. As you go deeper into structured training, LT-anchored zones become worth the extra testing.
Tracking Fitness Through Zones
A clean fitness marker over time:
- Zone 2 pace at the same HR should drift faster over weeks of base training
- Recovery HR (drop in HR 60 seconds after stopping a hard interval) should improve — 30 bpm drop in 60 s is a good benchmark
- Resting HR should trend down 5–10 bpm over months of consistent endurance work
Track these three monthly and you'll see real adaptation even when race times haven't moved yet.
Heart Rate Variability (HRV) — the Bonus Metric
HRV measures the variation in time between heartbeats. Higher HRV generally indicates better recovery; lower HRV flags accumulated fatigue or stress.
Most modern wearables (Whoop, Garmin, Oura, Apple Watch) track HRV overnight. Three rules:
- Use personal baseline, not population averages
- Trend matters — a drop relative to your 7-day average means rest is needed
- Single readings are noisy — don't overreact to one bad night
HRV doesn't replace zone training. It tells you how hard to train on a given day; zones tell you what hard means for that day.
Common Mistakes
- Treating Z3 as the default. It feels productive but is hard to recover from. Most cardio should be Z1–Z2.
- Using
220 − age. Use Tanaka or a tested max. - Comparing zones across sports. Cycling HRmax is typically 5–10 bpm lower than running HRmax for the same person. Use sport-specific maxes.
- Holding pace at the expense of zone. If pace pushes you into Z4 on an easy day, slow down. The plan is the plan.
- Ignoring perceived effort. RPE (1–10 scale) is a fine cross-check when your HR data looks weird.
Frequently Asked Questions
What if I don't know my resting heart rate?
Use the %HRmax method (no resting HR needed). Or measure it: 60 seconds of pulse counting first thing in the morning, three days in a row, then average.
Should I worry about a high resting heart rate?
A resting HR consistently above ~85 bpm in a healthy adult — or a sudden 10+ bpm rise without explanation — is worth flagging with a doctor. Lower is generally better but very low (<40 bpm) in untrained people also deserves a check.
Can I train in Zone 5 every day?
No. Zone 5 sessions need full recovery — typically 48–72 hours between hard sessions. Daily Z5 is a fast track to overreaching and injury.
How long does it take to see zone improvements?
Your Z2 pace at the same heart rate should start improving within 4–6 weeks of consistent base work. Race-pace gains in Z4 take 8–12 weeks of structured intervals.
Do strength athletes need zone training?
For health and recovery, yes — 1–2 sessions/week of Z2 cardio supports overall conditioning. For pure powerlifting performance the benefit is smaller, but the general-health case is strong.
Bottom Line
- Compute HRmax and zones with our Heart Rate Zone Calculator (Tanaka + optional Karvonen).
- Spend most weekly cardio volume in Zones 1–2.
- Use Zone 4–5 intentionally, with full recovery between sessions.
- Re-test or re-estimate every few months — fitness and resting HR both move.
Heart-rate zones turn cardio from a guess into a plan. The plan beats the guess almost every time.
Health and fitness calculations are estimates only and not medical advice. If you have a heart condition, take medication that affects heart rate (e.g., beta-blockers), or experience chest pain or unusual symptoms while exercising, consult a healthcare provider before training by zones.