Polar Heart Rate Zone Calculator
Your Training Results
Based on your age and resting heart rate, here are your personal Polar training zones:
| Zone | Intensity | Range (BPM) |
|---|
Estimated Max HR: BPM
Heart Rate Reserve (HRR): BPM
Understanding Your Polar Heart Rate Zones
Polar heart rate training is based on five specific intensity zones. These zones are calculated using your Maximum Heart Rate (MHR) and often refined using the Karvonen formula, which incorporates your Resting Heart Rate (RHR). By training within specific zones, you can target different energy systems and physiological adaptations.
Zone 1: Very Light (50–60%)
This zone is ideal for warm-ups, cool-downs, and active recovery. Training here improves overall health and helps you recover from harder sessions. It feels easy and you can hold a conversation without any effort.
Zone 2: Light (60–70%)
The "fat-burning" zone. Zone 2 training builds aerobic endurance and improves the body's ability to use fat as an energy source. This is the foundation of any endurance training program.
Zone 3: Moderate (70–80%)
In Zone 3, you improve your aerobic power and cardiovascular efficiency. It's slightly more challenging, and your breathing will be deeper, but you should still be able to speak in short sentences.
Zone 4: Hard (80–90%)
Training in Zone 4 increases your anaerobic capacity and moves your lactate threshold higher. This is "speed endurance" training. You will feel significant muscle fatigue and heavy breathing.
Zone 5: Maximum (90–100%)
This is all-out effort. Zone 5 training improves your maximal oxygen uptake (VO2 max) and peak performance. It is very taxing and should only be performed in short intervals by well-trained athletes.
How the Calculation Works
This calculator uses the Karvonen Formula, which is widely considered more accurate than simple percentages because it accounts for your fitness level through your resting heart rate. The formula is:
Example Calculation
If you are 40 years old with a resting heart rate of 60 BPM:
- Max HR: 220 – 40 = 180 BPM
- Heart Rate Reserve: 180 – 60 = 120 BPM
- Zone 2 (60% Lower Limit): (120 × 0.60) + 60 = 132 BPM
- Zone 2 (70% Upper Limit): (120 × 0.70) + 60 = 144 BPM
Your Zone 2 target range would be 132 to 144 BPM.