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.
予備心拍数
135bpm
185 − 50
最大心拍数
185bpm
安静時心拍数
50bpm
| ゾーン | 範囲 | 鍛えられるもの |
|---|---|---|
| Z1 | リカバリー 118–131 bpm | アクティブリカバリーとウォームアップ。疲労を加えずに血流を促進します。 非常に楽、RPE 1〜2。普通に会話でき、ほとんど息が上がりません。 |
| Z2 | エンデュランス 131–145 bpm | 有酸素的な土台、脂質酸化、毛細血管密度を養う、日々の基盤となるゾーンです。 快適、RPE 3〜4。完全な文章で話せます。 |
| Z3 | テンポ 145–158 bpm | 有酸素能力と筋持久力。「やや強い」定常的な運動です。 頑張っている、RPE 5〜6。短い文章のみ。 |
| Z4 | スレッショルド 158–172 bpm | 乳酸性作業閾値、持続可能なレースペースの上限です。 きつい、RPE 7〜8。一度に数語のみ。 |
| Z5 | VO₂max 172–185 bpm | 短く強いインターバルで最大有酸素パワーとVO₂maxを高めます。 非常にきつい〜最大、RPE 9〜10。会話不可。 |
Z1 · リカバリー. アクティブリカバリーとウォームアップ。疲労を加えずに血流を促進します。 非常に楽、RPE 1〜2。普通に会話でき、ほとんど息が上がりません。
Z2 · エンデュランス. 有酸素的な土台、脂質酸化、毛細血管密度を養う、日々の基盤となるゾーンです。 快適、RPE 3〜4。完全な文章で話せます。
Z3 · テンポ. 有酸素能力と筋持久力。「やや強い」定常的な運動です。 頑張っている、RPE 5〜6。短い文章のみ。
Z4 · スレッショルド. 乳酸性作業閾値、持続可能なレースペースの上限です。 きつい、RPE 7〜8。一度に数語のみ。
Z5 · VO₂max. 短く強いインターバルで最大有酸素パワーとVO₂maxを高めます。 非常にきつい〜最大、RPE 9〜10。会話不可。
- Karvonen法はゾーンを予備心拍数（HRmax − 安静時心拍数）に基づかせるため、単純な%HRmaxよりもあなたのフィットネスに合わせてゾーンを個別化します。安静時心拍数の低いフィットなアスリートには、それに応じて低い目標値が設定されます。
- 安静時心拍数は、朝起きてすぐ、横になったまま、カフェインを摂る前に測定してください。安静時心拍数の5 bpmの誤差がすべてのゾーンをずらします。
パーソナライズされた結果のPDFと、いつでも再表示できるQRコード付き。
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