Quick Answer
Heart rate zone training divides effort into five zones based on your maximum heart rate. Zone 1 (50–60%) is recovery. Zone 2 (60–70%) is aerobic base — where most of your training should happen. Zone 3 (70–80%) is tempo. Zone 4 (80–90%) is threshold. Zone 5 (90–100%) is maximum effort. The 80/20 rule: 80% of training in Zones 1–2, 20% in Zones 3–5. To find your zones, estimate max HR with 220 minus your age, then multiply by the zone percentages. One important note: cycling zones run 5–10 bpm lower than running zones — you need a separate set for each sport.
The 5 Heart Rate Zones Explained
| Zone | % Max HR | How it feels | Training purpose | Typical session type |
|---|---|---|---|---|
| Zone 1 | 50–60% | Effortless; full conversation without effort; could go for hours | Active recovery; promotes blood flow without training stress | Recovery run/ride, warm-up, cool-down |
| Zone 2 | 60–70% | Comfortable; can speak in full sentences; feels like sustained work | Aerobic base building; fat oxidation; mitochondrial development | Long runs, easy rides, base endurance (2–5 hrs) |
| Zone 3 | 70–80% | Moderate; breathing deeper; short sentences; noticeably working | Aerobic capacity; comfortably hard; bridges base and threshold | Tempo runs, steady-state rides (20–60 min efforts) |
| Zone 4 | 80–90% | Hard; breathing laboured; few words possible; sustainable for 10–40 min | Lactate threshold; raises FTP/race pace; FTP/threshold intervals | Threshold intervals: 2–4 × 10–20 min |
| Zone 5 | 90–100% | Maximum; cannot speak; unsustainable beyond a few minutes | VO2max; aerobic ceiling; top-end speed | VO2max intervals: 5–8 × 3–5 min; short sprints |
Some coaching systems and platforms (TrainingPeaks, Garmin) subdivide Zone 5 into 5a, 5b, and 5c, or use 6- and 7-zone models for more granular intensity control at higher efforts. Joe Friel’s widely-used system uses 7 zones. For most recreational runners and cyclists, five zones provide sufficient resolution for effective training structure.
The single most important principle: 80% of your total training time should be in Zones 1 and 2. Only 20% in Zones 3–5. This applies whether you run three times a week or train for an Ironman. Elite athletes at every level follow this distribution — and most recreational athletes do the opposite.
How to Find Your Maximum Heart Rate
All percentage-based zone calculations depend on an accurate maximum heart rate. There are three main approaches, ranging from convenient to precise:
Method 1: Age-Based Formula (Quick Estimate)
The simplest approach: 220 − your age. A 40-year-old estimates 180 bpm; a 55-year-old estimates 165 bpm. This formula has a standard deviation of approximately ±10–12 bpm — meaning a 40-year-old’s actual max HR might reasonably be anywhere from 168 to 192 bpm. It is adequate for beginners and as a starting point, but should not be relied upon for precise zone training.
A more accurate age-based formula — particularly for athletes over 40 — is the Tanaka formula: 208 − (0.7 × age). A 40-year-old estimates 180 bpm (same in this case); a 55-year-old estimates 169.5 bpm (vs 165 bpm with 220-age). The Tanaka formula was developed from a meta-analysis of 351 studies and performs better for older athletes where the 220-age formula tends to underestimate max HR.
Method 2: Field Test (More Accurate)
A field test produces a more personalised max HR than any formula. The standard running test: warm up thoroughly for 15–20 minutes including several short accelerations. Find a hill that takes approximately 2 minutes to run up. Run the hill twice at near-maximum effort, with 3 minutes recovery between. Attempt a final sprint at the base of the second hill at truly maximum effort. The highest HR recorded during or immediately after this effort is your approximate maximum.
For cycling: a ramp test on a smart trainer (power increases every minute until failure) will typically produce a max HR reading at the point of failure. The highest HR from any race or hard ride in the previous 6 months is also a valid reference point.
Method 3: Lactate Threshold HR (Most Accurate for Zone Setting)
Joe Friel’s preferred method for setting training zones is not maximum heart rate at all — it is Lactate Threshold Heart Rate (LTHR). To find LTHR: warm up, then run or ride at race-like effort (as hard as you can sustain for a full 30 minutes without blowing up early). At 10 minutes into the effort, press the lap button on your watch. After 30 minutes, check average HR for the last 20 minutes. This figure is your LTHR.
LTHR-based zones are more individually precise than max HR-based zones because lactate threshold varies significantly between athletes of similar ages — it is more sensitive to training status and individual physiology. Our cycling training plan guide and lactate threshold cycling guide cover how LTHR applies specifically to cycling zones and FTP-based training.
The Karvonen Formula: More Accurate Zone Calculation
Standard zone calculation uses max HR alone. The Karvonen formula (also called the Heart Rate Reserve method) uses both maximum and resting heart rate to produce more individualised zones. It is particularly useful for trained athletes, who tend to have lower resting heart rates — a 35-year-old runner with a resting HR of 45 bpm trains very differently from one with a resting HR of 72 bpm, even with identical max HRs.
Karvonen formula: Target HR = [(Max HR − Resting HR) × % intensity] + Resting HR
Example: A 40-year-old with max HR of 180 bpm and resting HR of 52 bpm calculating Zone 2 (60–70%):
Zone 2 lower = [(180 − 52) × 0.60] + 52 = [128 × 0.60] + 52 = 76.8 + 52 = 129 bpm
Zone 2 upper = [(180 − 52) × 0.70] + 52 = [128 × 0.70] + 52 = 89.6 + 52 = 142 bpm
Compare this to the simple % max HR method for the same athlete:
Zone 2 lower = 180 × 0.60 = 108 bpm
Zone 2 upper = 180 × 0.70 = 126 bpm
The Karvonen method produces a significantly higher Zone 2 ceiling for this well-trained athlete with a low resting HR. Training at 108–126 bpm (simple method) might feel too easy and produce minimal adaptation; 129–142 bpm (Karvonen) better reflects the actual training stimulus needed. Use our heart rate training zones calculator to calculate both sets automatically from your personal data.
Zone-by-Zone Guide: What Each Zone Actually Does
Zone 1 — Active Recovery
Zone 1 feels almost embarrassingly easy. Many athletes skip it entirely or push it toward Zone 2. But genuine Zone 1 work — easy spinning, a gentle jog, a recovery walk — serves a specific purpose: it promotes blood flow and metabolite clearance after hard sessions without adding meaningful training stress. The day after a hard interval session, a Zone 1 ride or jog accelerates recovery compared to complete rest, at no cost to the training load.
Zone 2 — The Foundation
Zone 2 is the most important training zone for any endurance athlete. At 60–70% max HR, the body works primarily aerobically using fat as its main fuel source. The primary adaptation driven by Zone 2 training is mitochondrial density — the number and size of mitochondria (the energy-producing organelles) in muscle cells. More mitochondria means more capacity to produce energy aerobically, faster recovery between hard efforts, and improved fat oxidation efficiency. These adaptations form the foundation that makes all higher-intensity training more effective.
The problem most athletes face: Zone 2 feels too easy. A genuinely easy Zone 2 run often feels uncomfortably slow compared to normal training pace. Runners who are used to pushing pace find it feels wrong to slow down enough to stay in Zone 2. But this is precisely the point — if Zone 2 training feels comfortably challenging rather than genuinely easy, you are most likely training in Zone 3, which is the grey zone that produces neither the aerobic base benefits of Zone 2 nor the quality adaptations of Zone 4.
The talk test is the simplest field check: if you cannot comfortably speak in complete sentences without pausing for breath, you are above Zone 2. This simple check matches laboratory measurements of Zone 2 upper limits surprisingly well. Our Zone 2 running pace guide covers the specific pace and effort targets for Zone 2 running at different fitness levels.
Zone 3 — The Grey Zone
Zone 3 is where most recreational athletes unknowingly spend the majority of their training time. It feels productive — you are working, sweating, breathing harder — but it is the least efficient training zone for endurance development. Zone 3 is hard enough to accumulate significant fatigue and require recovery, but not hard enough to drive the specific adaptations of Zone 4 (lactate threshold improvement) or the aerobic base of Zone 2. Many coaches describe Zone 3 as “too hard to be easy, too easy to be hard.”
Zone 3 has legitimate uses — race-pace efforts for 5km and 10km runners, sustained climbing for cyclists, and specific aerobic capacity work. But as the dominant training intensity, it produces the plateau effect most recreational athletes experience after their initial fitness gains.
Zone 4 — Threshold
Zone 4 targets the lactate threshold — the intensity at which lactate accumulates faster than it can be cleared. Training regularly at this intensity raises the threshold, meaning you can sustain harder efforts before lactate-driven fatigue sets in. This is what produces meaningful improvements in 10km through half marathon pace for runners, and FTP for cyclists. Typical Zone 4 sessions: 2–4 × 10–20 minute intervals at threshold HR with 3–5 minutes recovery. One Zone 4 session per week is the typical prescription for most endurance athletes. Our interval training guide covers the specific session structures that develop threshold most effectively.
Zone 5 — VO2 Max
Zone 5 intervals raise the aerobic ceiling — the maximum rate at which your cardiovascular system can deliver oxygen to working muscles. They are the hardest sessions in any training plan, require the most recovery (48–72 hours before the next hard session), and should make up a small fraction of total training volume. Typical Zone 5 sessions: 5–8 × 3–5 minutes at 90–100% max HR with equal or longer recovery. These should only be introduced after a strong Zone 2 base is established — attempting Zone 5 work without aerobic base typically produces overtraining rather than adaptation.
Running vs Cycling Heart Rate Zones: The Critical Difference
Heart rate zones are sport-specific. Cycling zones are typically 5–10 beats per minute lower than running zones. The reason: cycling is non-weight-bearing and recruits fewer total muscle groups than running. With less total muscle mass working, the cardiovascular system is under less demand to deliver oxygen at any given perceived effort — so heart rate is lower at equivalent intensity.
| Zone | Running HR (example: 180 max HR) | Cycling HR (−7 bpm typical) | Note |
|---|---|---|---|
| Zone 1 | 90–108 bpm | 83–101 bpm | Recovery rides feel even easier than recovery runs |
| Zone 2 | 108–126 bpm | 101–119 bpm | Long ride pace is lower HR than equivalent run pace |
| Zone 3 | 126–144 bpm | 119–137 bpm | Tempo efforts feel similar but show lower HR |
| Zone 4 | 144–162 bpm | 137–155 bpm | Threshold intervals — use sport-specific zones on your device |
| Zone 5 | 162–180 bpm | 155–173 bpm | VO2max — HR may not reach running max on bike |
Triathletes and athletes who train across both sports must set separate zone profiles for running and cycling in their training watch or platform. Using running zones during a bike ride will push cycling effort too high — the watch will tell you that you’re in Zone 2 when you’re actually in Zone 3. Our cycling training plan and Zone 2 running guide both reference sport-specific zones for this reason. For cyclists wanting to benchmark where their heart rate sits against typical performance levels, our typical cycling speed guide provides context across fitness levels and age groups.
Heart Rate Drift: What It Is and Why It Happens
Cardiac drift is the gradual rise in heart rate during a constant-pace effort — a Zone 2 run at consistent pace will show a higher HR at kilometre 15 than at kilometre 3. This is normal and expected, driven by progressive dehydration reducing stroke volume (the heart beats faster to compensate), rising core temperature, and muscle fatigue. Heart rate drift is more pronounced in heat and humidity.
Practical implication: on long Zone 2 runs or rides, allow HR to drift upward naturally rather than slowing pace to keep HR artificially capped. The effort level (pace) is more representative of actual training stimulus on long sessions than trying to maintain an exact HR target throughout. Our guide on building a cardio base covers how aerobic fitness development over months reduces cardiac drift at the same pace — one of the clearest markers of improving Zone 2 fitness.
Signs You're Training in the Wrong Zone
You’re probably spending too much time in Zone 3 (the grey zone) if: You feel tired but not properly challenged. Your easy runs never feel easy. Your performance has plateaued despite consistent training. You struggle to complete hard interval sessions with quality. You feel chronically fatigued but not improving. These are the hallmarks of an athlete who has drifted into medium-intensity training for most sessions.
The fix: Make your easy days genuinely easy (Zone 1–2, pass the talk test) and make your hard days genuinely hard (Zone 4–5, structured intervals at target HR). The discipline required to slow down on easy days is harder than the discipline to push on hard days — but it is the more important habit. Our running frequency science guide covers how training intensity distribution across a week affects injury rates and adaptation, specifically addressing the grey zone problem.
For older athletes, the same principles apply but the recovery margins are tighter. Zone 2 training remains as important at 60 as at 30, but Zone 4–5 sessions require more recovery spacing. Our sprint training for older athletes guide covers how to maintain high-intensity capability while respecting longer recovery needs.
Train Smarter With Structured Coaching
A SportCoaching coach sets your precise training zones and ensures every session hits the right intensity — so your easy days are truly easy, your hard days produce real adaptation, and your fitness improves consistently. AUD $143/month, no lock-in, 90-day performance guarantee.
FAQ: Heart Rate Zone Training
What are the 5 heart rate zones?
Zone 1 (50–60% max HR): recovery. Zone 2 (60–70%): aerobic base/endurance. Zone 3 (70–80%): tempo/moderate. Zone 4 (80–90%): threshold. Zone 5 (90–100%): VO2max. The 80/20 rule: 80% of training in Zones 1–2, 20% in Zones 3–5.
How do I calculate my heart rate zones?
Step 1: find max HR (220 − age, or Tanaka: 208 − 0.7 × age). Step 2: multiply by zone percentages. For more accuracy, use the Karvonen formula (which uses resting HR too) or test LTHR directly with a 30-minute time trial. Use the heart rate zone calculator on this site to calculate your zones automatically.
Why is Zone 2 training so important?
Zone 2 builds mitochondrial density and fat oxidation — the aerobic foundation all hard training depends on. Most athletes train too hard on easy days (Zone 3), which accumulates fatigue without building aerobic base. Zone 2 at 80% of training volume is the consistent finding across elite endurance coaches worldwide.
Are cycling heart rate zones the same as running zones?
No — cycling zones are typically 5–10 bpm lower than running zones. Set separate zone profiles for each sport in your training watch or platform.
How do I know if I’m in Zone 2?
The talk test: you can speak in full sentences comfortably. If you have to pause mid-sentence to breathe, you are above Zone 2. This simple check matches laboratory Zone 2 measurements well for most athletes.
