Heart Rate Reserve: Better Zones with the Karvonen Method
What heart rate reserve (HRR) is, the Karvonen formula that turns it into training zones, why it beats plain %HRmax, and how to measure the two inputs.
Heart rate reserve (HRR) is the gap between your maximum and resting heart rates. If your max is 190 and you rest at 50, your reserve is 140 beats. The Karvonen method takes a percentage of that reserve and adds your resting heart rate back on top. That one adjustment makes your zones more personal, especially if you are very fit or just starting out.
What is heart rate reserve?
Your heart rate never drops to zero, so not all of your 190 bpm is usable training range. Heart rate reserve is the part that is:
HRR = maximum heart rate − resting heart rate
A fitter heart pumps more blood per beat, so it beats slower at rest. A fitter person therefore has a larger reserve than an unfit person with the same maximum.
The Karvonen formula
The Karvonen method, published by Finnish physiologist Martti Karvonen in 1957, sets each zone boundary like this:
Target HR = resting HR + (intensity % × heart rate reserve)
Say your max is 190, your resting heart rate is 50, and you want the bottom of Zone 2 at 60% intensity:
- Heart rate reserve = 190 − 50 = 140 bpm
- 60% of 140 = 84 bpm
- Add resting back: 84 + 50 = 134 bpm
A plain "60% of max" would give 114 bpm, 20 beats lower.
Cadangan detak jantung
135bpm
185 − 50
Detak jantung maksimal
185bpm
Detak jantung istirahat
50bpm
| Zona | Rentang | Apa yang dilatih |
|---|---|---|
| Z1 | Pemulihan 118–131 bpm | Pemulihan aktif dan pemanasan; melancarkan aliran darah tanpa menambah kelelahan. Sangat ringan, RPE 1–2. Bisa mengobrol penuh, napas hampir tidak terengah. |
| Z2 | Daya Tahan 131–145 bpm | Basis aerobik, oksidasi lemak dan kepadatan kapiler, zona andalan sehari-hari. Nyaman, RPE 3–4. Bisa mengucapkan kalimat utuh. |
| Z3 | Tempo 145–158 bpm | Kapasitas aerobik dan daya tahan otot; kerja stabil yang 'cukup berat'. Berusaha, RPE 5–6. Hanya kalimat pendek. |
| Z4 | Ambang 158–172 bpm | Ambang laktat, batas atas kecepatan lomba yang bisa kamu pertahankan. Berat, RPE 7–8. Beberapa kata sekaligus saja. |
| Z5 | VO₂max 172–185 bpm | Daya aerobik maksimal dan VO₂max lewat interval pendek yang berat. Sangat berat hingga maksimal, RPE 9–10. Tidak bisa bicara. |
Z1 · Pemulihan. Pemulihan aktif dan pemanasan; melancarkan aliran darah tanpa menambah kelelahan. Sangat ringan, RPE 1–2. Bisa mengobrol penuh, napas hampir tidak terengah.
Z2 · Daya Tahan. Basis aerobik, oksidasi lemak dan kepadatan kapiler, zona andalan sehari-hari. Nyaman, RPE 3–4. Bisa mengucapkan kalimat utuh.
Z3 · Tempo. Kapasitas aerobik dan daya tahan otot; kerja stabil yang 'cukup berat'. Berusaha, RPE 5–6. Hanya kalimat pendek.
Z4 · Ambang. Ambang laktat, batas atas kecepatan lomba yang bisa kamu pertahankan. Berat, RPE 7–8. Beberapa kata sekaligus saja.
Z5 · VO₂max. Daya aerobik maksimal dan VO₂max lewat interval pendek yang berat. Sangat berat hingga maksimal, RPE 9–10. Tidak bisa bicara.
- Karvonen menetapkan zona berdasarkan cadangan detak jantungmu (HRmax − detak jantung istirahat), sehingga lebih mempersonalisasi zona sesuai kebugaranmu dibanding %HRmax biasa, atlet yang bugar dengan detak jantung istirahat rendah mendapatkan target yang lebih rendah pula.
- Ukur detak jantung istirahat pertama kali di pagi hari, sambil berbaring, sebelum kafein. Kesalahan 5 bpm pada RHR menggeser setiap zona.
PDF berisi hasil personalmu, plus kode QR untuk membukanya kembali kapan saja.
Why does Karvonen beat plain %HRmax?
Percent-of-maximum zones treat everyone with the same max identically. Karvonen folds in resting heart rate, a rough proxy for fitness:
- It accounts for your conditioning. A trained athlete resting at 45 and a beginner resting at 75 get different zones even with the same max.
- The zones track your fitness. As resting heart rate drops, your reserve grows and the zones update. A fixed %HRmax band never moves.
- It spreads the easy end out. Plain %HRmax puts easy efforts at implausibly low heart rates. Adding resting heart rate back lifts the low zones to numbers you can train at.
For how the different systems carve up the range, compare the heart-rate zone models.
How do I find the two numbers I need?
Resting heart rate (RHR). Measure it first thing in the morning, before you get up, averaged over several days. A chest strap or the overnight reading from a wearable both work. A daytime desk reading runs high.
Maximum heart rate (HRmax). Age formulas (220 − age, or the more accurate Tanaka, 208 − 0.7 × age) can be off by 10+ beats for any individual. A field test gives a far better number. See finding your maximum heart rate for both, or the max heart rate calculator for the estimate.
Karvonen vs. lactate-threshold zones
Karvonen is still anchored to your maximum, which barely responds to training and is hard to measure safely. The most individual anchor is your threshold. Zones set from your lactate-threshold heart rate sit where your physiology changes and rise as you get fitter. Many athletes start with Karvonen and move to LTHR zones after a 30-minute test.
For easy aerobic work, see Zone 2 heart rate, explained.
Sources
- Karvonen, M. J., Kentala, E., & Mustala, O. (1957), the original heart-rate-reserve study
- Tanaka, Monahan & Seals (2001), maximum-heart-rate estimation