What is the difference between % HRmax and Karvonen (HRR) method?

Both methods calculate training zones, but they use different reference points: % of HRmax (simpler): - Zones are a direct percentage of your maximum heart rate - Example: Zone 2 = 60-70% of HRmax 185 = 111-130 bpm - Does not account for fitness level - Same zones for a fit person (HRrest 45) and an unfit person (HRrest 80) at the same HRmax - Used by most consumer apps and GPS watches Karvonen / Heart Rate Reserve method (more individualised): - Uses Heart Rate Reserve (HRR) = HRmax - HRrest - Target HR = HRrest + (HRR × intensity%) - Example: HRmax 185, HRrest 58, HRR = 127 Zone 2 (60-70% HRR): 58 + 127×0.60 to 58 + 127×0.70 = 134-147 bpm - Fitter people (lower HRrest) get higher absolute zones for the same percentage - More physiologically accurate because two people with the same HRmax but different fitness levels have very different cardiovascular capacity at the same absolute heart rate Which to use: - Beginner or casual exerciser: % HRmax is fine - Athlete, competitive training, wants precision: Karvonen is recommended - Karvonen zones are typically 10-20 bpm higher than % HRmax zones for fit individuals with low resting HR

What is Zone 2 training and why is it so popular?

Zone 2 training (60-70% HRmax, or 60-70% HRR in Karvonen) is long, easy, aerobic exercise performed at a pace where you could hold a full conversation. It has become widely discussed due to research showing it is the foundation of elite endurance performance. What happens physiologically in Zone 2: - Primary fuel: fat oxidation (80-90% of fuel from fat vs carbs) - Mitochondrial biogenesis: creation of new mitochondria — the cellular powerhouses - Increased capillary density in muscles - Improved cardiac stroke volume (heart pumps more blood per beat) - Lactate stays low (< 2 mmol/L), fully cleared at this intensity Why it matters: - The aerobic base determines how hard and how long you can sustain intensity - All elite endurance athletes do 75-85% of training volume in Zone 2 or below - Zone 2 produces adaptations that no other zone can efficiently replicate - It is recovery-friendly: you can do more volume, with less muscle damage, with faster recovery Common mistake: Grey zone (Zone 3) training - Many recreational athletes train at moderate effort (Zone 3) because it 'feels productive' - Zone 3 is hard enough to create significant fatigue but not intense enough to produce VO2 max stimulus - This is the 'grey zone' — too hard to do a lot of, not hard enough for the key adaptations - Result: constant moderate fatigue, limited improvement Practical Zone 2 test: if you can't hold a full conversation comfortably, you're above Zone 2. Reduce pace.

What is polarised training and what does the 80/20 split mean?

Polarised training (Seiler 2009) is a training intensity distribution where athletes do approximately 80% of their training volume at low intensity (Zone 1-2) and 20% at high intensity (Zone 4-5), with very little time in the middle zones (Zone 3). The evidence: Dr Stephen Seiler at the University of Agder analysed the training diaries of world-class endurance athletes across rowing, cross-country skiing, cycling, and running. He found consistently: - 75-80% of sessions at low intensity (conversational pace) - 15-20% at high intensity (intervals, hard efforts) - Less than 10% in the 'tempo' zone (lactate threshold) Randomised trials comparing training approaches: - Polarised (80/20) vs Threshold (mostly Zone 3): polarised produced greater VO2 max gains in 9-week RCTs in recreational runners - Reason: Zone 4-5 intervals produce the strongest VO2 max stimulus; Zone 1-2 allows recovery and builds aerobic base; Zone 3 creates chronic fatigue without maximising either Practical implementation for a 5-day training week: - 4 easy days (Zone 1-2): long runs, easy runs, recovery sessions - 1 hard day (Zone 4-5): interval session, hill repeats, tempo intervals at race pace - Week 2: 3 easy + 2 hard Note: polarised is not a rigid rule. Most athletes do 'threshold-polarised' — some Zone 3 work is included, especially for shorter distance specialists (1500m-5K runners).

What is the Maffetone MAF heart rate and when should I use it?

The Maffetone Method, developed by Dr Phil Maffetone, uses the MAF (Maximum Aerobic Function) heart rate as the ceiling for all aerobic base-building training. The formula: MAF HR = 180 - age With adjustments: - Subtract 10: if recovering from illness, injury, or on medication - Subtract 5: if new to training (less than 2 consistent years) or returning after a break - No change: if training consistently for 2+ years without injury - Add 5: if training has been consistent and improving for 2+ years Example: age 38, consistent training for 3 years: MAF HR = 180 - 38 = 142 bpm (no adjustment) MAF range: 132-142 bpm (work in the 10-bpm window below MAF) What happens when you stay below MAF: - You stay fully aerobic — primarily fat-burning metabolism - Lactate remains negligible - No sympathetic nervous system stress that accumulates over repeated sessions - You can recover fully before the next session When to use Maffetone: - For aerobic base-building phases (pre-season, early season) - If you frequently get injured or overtrained - For high training volume blocks (marathon preparation) - For runners who want to improve efficiency and fat oxidation Limitation: MAF pace is often much slower than expected — especially for recreational athletes. At MAF HR, many people run 6-8 min/km. This requires patience. MAF pace improves over 3-6 months of consistent base training. Note: Maffetone is not evidence-based in the clinical sense — it is practitioner-derived from decades of coaching. The physiological rationale is sound but no RCTs have validated the 180-age formula specifically.

How do I find my true maximum heart rate?

Estimated HRmax formulas (like 220-age or Tanaka 208-0.7×age) have a standard deviation of ±7-12 bpm. This means your actual HRmax could be 15 bpm higher or lower than the formula predicts. For precision training, measuring your actual HRmax is better. Methods to measure HRmax (safest to most effort): 1. Maximal exercise test (lab) — most accurate: - Graded treadmill or cycle ergometer test to volitional exhaustion - Monitored by a doctor or exercise physiologist - Provides HRmax + VO2 max simultaneously - Best option for those with cardiac risk factors 2. Field test — running: - Warm up 15 min at easy pace - Run up a long hill at maximal effort for 2-3 min - Sprint flat out for the last 30 seconds - Recorded peak = HRmax (requires chest strap HR monitor — wrist optical is too slow) - Repeat 3x with 3 min recovery; take the highest value 3. Race data: - Your peak HR during the final sprint of a hard 5K or 10K race - Accurate if you truly emptied the tank - Wrist HR monitor often underestimates at very high HR — chest strap preferred 4. Wearable device peak: - Some devices (Garmin, Polar) record all-time peak HR - Check workout history for the highest value ever recorded - Only reliable if device has documented your hard efforts Important: do NOT test HRmax if you have known or suspected cardiac conditions, recent illness, or are over 45 without regular training history. Consult a doctor first.

Which zone system should I use — 5-zone, 7-zone, or 3-zone?

All three zone systems are valid — they divide the same heart rate spectrum differently. The best choice depends on your sport and purpose. 5-Zone System (recommended for most people): - Used by Garmin, Polar, Suunto, Strava, TrainingPeaks - Well-understood; most training plans reference it - Broad enough zones to be practical with natural HR variation - Best for: general fitness, running, cycling, multi-sport 7-Zone System (Coggan — more nuanced): - Originally designed for cycling power zones, adapted for HR - Separates Neuromuscular (Z7) from Anaerobic (Z6) - Better for: advanced cyclists, structured high-intensity programming - Drawback: zones are so narrow (5-7%) that natural HR variation often crosses zone boundaries 3-Zone System (Scandinavian research model): - Based on physiological thresholds: aerobic threshold (VT1) and anaerobic threshold (VT2) - Zone 1 = below VT1 (fully aerobic), Zone 2 = between thresholds, Zone 3 = above VT2 - The simplest model supported by the most research - Best for: pure endurance athletes (marathon, triathlon, cross-country skiing) - The 80/20 (polarised) model is best applied with the 3-zone framework Practical recommendation: - Start with 5-zone — it aligns with your GPS watch zones - If you do structured intervals or race preparation, switch to 7-zone for more precision - For polarised training understanding, use 3-zone to keep it simple

Heart Rate Training Zones Calculator — 3 Zone Systems

The Heart Rate Training Zones Calculator calculates personalised training zones using three HRmax formulas (Tanaka 2001, Fox 1971, Gellish 2007) and two zone calculation methods (% of HRmax and Karvonen Heart Rate Reserve). Supports three zone systems: 5-Zone (Garmin/Polar/Strava standard), 7-Zone (Coggan), and 3-Zone ..

YOUR DETAILS

AGE

yrs

HRMAX FORMULA

ZONE CALCULATION METHOD

ZONE SYSTEM

Aerobic base training ceiling

YOUR HEART RATE ZONES

HRMAX

184

bpm

HRR

126

bpm reserve

METHOD

% HRmax

Z1 Recovery92–110 bpm

Z2 Aerobic110–129 bpm

Z3 Tempo129–147 bpm

Z4 Threshold147–166 bpm

Z5 Max166–184 bpm

ZONE BARS — 5ZONE · % HRmax · HRmax 184 bpm

Z1 Recovery92–110 bpm

50–60%

Fat oxidation, recovery, warm-up and cool-down

Z2 Aerobic110–129 bpm

60–70%

Aerobic base, mitochondrial density, fat burning

Z3 Tempo129–147 bpm

70–80%

Aerobic efficiency, sustained effort training

Z4 Threshold147–166 bpm

80–90%

Lactate threshold, race pace 10K–half marathon

Z5 Max166–184 bpm

90–100%

Maximum cardiac output, VO2 max stimulus

HRMAX FORMULA COMPARISON (age 35)

Tanaka (2001) (208 - 0.7×age)184 bpm

Gellish (2007) (207 - 0.7×age)183 bpm

Fox (1971) (220 - age)185 bpm

80/20 TRAINING DISTRIBUTION (Polarised)

80% Easy

20% Hard

EASY (Z1–Z2)

<129 bpm

80% of weekly volume

HARD (Z4–Z5)

>147 bpm

20% of weekly volume

Polarised training (Seiler 2009): 80% easy + 20% hard produces superior VO2 max gains vs threshold-only training in most studies.

FULL ZONE REFERENCE TABLE

Zone	BPM Range	%	Feel	Benefit
Z1 Recovery	92–110	50–60%	Very easy — can sing	Fat oxidation, recovery, warm-up and cool-down
Z2 Aerobic	110–129	60–70%	Easy — full conversation	Aerobic base, mitochondrial density, fat burning
Z3 Tempo	129–147	70–80%	Moderate — broken sentences	Aerobic efficiency, sustained effort training
Z4 Threshold	147–166	80–90%	Hard — few words only	Lactate threshold, race pace 10K–half marathon
Z5 Max	166–184	90–100%	Maximum — cannot speak	Maximum cardiac output, VO2 max stimulus

Created with ❤️ byeaglecalculator.com

HOW TO USE

1
Enter your age. All zone calculations begin with your maximum heart rate (HRmax), which is estimated from age using one of three validated formulas. Tanaka (2001) is the most accurate for most adults — it is selected by default. Alternatively, enter your measured HRmax from a maximal exercise test, a recent hard race, or a wearable device's recorded peak.
2
Choose your zone calculation method. The '% of HRmax' method divides your max into percentage bands — simple and widely used in apps like Garmin, Polar, and Strava. The Karvonen (Heart Rate Reserve) method is more individualised: it accounts for your fitness level via resting heart rate, spreading zones across the actual usable heart rate range. Enter your resting heart rate if using Karvonen — measure it in the morning lying still for 2-3 minutes.
3
Select a zone system: 5-Zone (most common, used by most GPS watches and apps), 7-Zone (more granular, used by some coaches and the Coggan system), or 3-Zone (Scandinavian research model — simple and widely supported by training science). All systems display the exact BPM range for each zone at your HRmax and the training benefit of each zone.
4
Optionally enable the Maffetone MAF HR. This is the ceiling heart rate for aerobic base building runs — staying below it ensures you stay fully aerobic and do not cross into anaerobic glycolysis. Select your fitness category (injured, beginner, consistent, improving) to apply the correct adjustment to the 180-minus-age formula.
5
Read the full results: the colour-coded zone bars on the right show each zone's position relative to your HRmax with exact BPM ranges. The HRmax formula comparison chart shows how all three formulas compare for your age. The 80/20 polarised training panel shows the easy and hard heart rate thresholds for optimal training distribution. The complete zone table appears below with BPM ranges, percentages, perceived effort, and training benefit for every zone.

WORKED EXAMPLE

Heart Rate Zone calculation for age 35, male, HRrest 58 bpm: HRMAX FORMULAS: Tanaka (recommended): 208 - 0.7×35 = 208 - 24.5 = 183.5 → 184 bpm Fox (classic): 220 - 35 = 185 bpm Gellish: 207 - 0.7×35 = 207 - 24.5 = 182.5 → 183 bpm HEART RATE RESERVE (Karvonen): HRR = HRmax - HRrest = 184 - 58 = 126 bpm 5-ZONE SYSTEM — % HRmax method (HRmax 184): Zone 1 (50-60%): 92–110 bpm → Recovery, fat burning Zone 2 (60-70%): 110–129 bpm → Aerobic base, long runs Zone 3 (70-80%): 129–147 bpm → Aerobic efficiency Zone 4 (80-90%): 147–166 bpm → Lactate threshold Zone 5 (90-100%): 166–184 bpm → VO2 max 5-ZONE SYSTEM — Karvonen method (HRmax 184, HRrest 58, HRR 126): Target HR = 58 + 126 × intensity% Zone 1 (50-60% HRR): 58 + 63 to 58 + 75.6 = 121–134 bpm Zone 2 (60-70% HRR): 58 + 75.6 to 58 + 88.2 = 134–146 bpm Zone 3 (70-80% HRR): 58 + 88.2 to 58 + 100.8 = 146–159 bpm Zone 4 (80-90% HRR): 58 + 100.8 to 58 + 113.4 = 159–171 bpm Zone 5 (90-100% HRR): 58 + 113.4 to 58 + 126 = 171–184 bpm Note: Karvonen Z2 = 134-146 bpm vs % HRmax Z2 = 110-129 bpm This 5-17 bpm difference is significant — fitter athletes should use Karvonen. MAFFETONE MAF HR (consistent training 2+ years): MAF = 180 - 35 = 145 bpm (no adjustment) MAF range = 135-145 bpm This falls within Zone 2 (Karvonen) — consistent with the 80/20 model. 80/20 POLARISED DISTRIBUTION: Easy threshold (below Z3): <146 bpm (Karvonen Z2 top) Hard threshold (Z4-Z5): >159 bpm 80% of weekly training volume should stay below 146 bpm.

REFERENCE FORMULAS

FORMULA REFERENCE TABLE

Name	Formula	Description
HRmax — Tanaka (2001)	HRmax = 208 - 0.7 × age	Most accurate general formula. Meta-analysis of 351 studies, 18-81yr. SD ±7 bpm. Recommended default.
HRmax — Fox (1971)	HRmax = 220 - age	Classic formula. Overestimates for fit adults, underestimates for older. SD ±10-12 bpm.
HRmax — Gellish (2007)	HRmax = 207 - 0.7 × age	Validated on 132 adults. Similar to Tanaka; 1 bpm lower intercept.
% HRmax Zones	Zone HR = HRmax × zone_percentage	Simple. Zone 1=50-60%, Zone 2=60-70%, Zone 3=70-80%, Zone 4=80-90%, Zone 5=90-100%.
Karvonen (HRR method)	Target HR = HRrest + (HRmax - HRrest) × intensity%	Heart Rate Reserve method. More individualised — accounts for fitness level via resting HR. Recommended for athletes.
HRR (Heart Rate Reserve)	HRR = HRmax - HRrest	The usable range of heart rate. Fit adults have lower resting HR, so larger HRR, so Karvonen zones are spread wider.
Maffetone MAF HR	MAF HR = 180 - age (+ adjustment)	Aerobic base ceiling. Adjustments: −10 if injured, −5 if new, 0 if consistent 2+ yr, +5 if improving. Stay below MAF for 80%+ of runs.
Polarised distribution	80% volume ≤ Zone 2 + 20% volume ≥ Zone 4	Seiler (2009): most successful endurance athletes train polarised, not at lactate threshold. Superior VO2 max gains in RCTs.

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Last updated: April 29, 2026 — HRmax: Tanaka et al. (2001), Fox (1971), Gellish et al. (2007) — Karvonen (1957) — Maffetone (1999) — Seiler (2009)