What Is Target Heart Rate?
Target heart rate (THR) is the range of beats per minute at which you should train to get the maximum benefits from your exercise. Training in the right zone allows you to burn fat efficiently, improve cardiovascular endurance, or reach peak performance, depending on your goals.
The Karvonen Formula
THR = ((Max HR - Resting HR) × Intensity %) + Resting HR
Where: Max HR = 220 - age HR Reserve = Max HR - Resting HR
The Karvonen formula is more accurate than simply using a percentage of maximum heart rate because it incorporates your resting heart rate (RHR), which is an indicator of your current fitness level. A lower RHR generally indicates better cardiovascular fitness.
The 5 Training Zones
Zone 1: Warm Up (50-60%)
This zone is perfect for warm-up and recovery. Here your body prepares for more intense exercise. It's also ideal for beginners starting their fitness journey.
Zone 2: Fat Burn (60-70%)
The preferred zone for weight loss. At this intensity, your body primarily uses fat reserves as energy. It's an intensity you can maintain for extended periods without excessive fatigue.
While the "fat burn zone" uses a higher percentage of fat as fuel, higher-intensity exercise burns more total calories and more fat in absolute terms. The best zone is the one you can maintain consistently.
Zone 3: Cardio (70-80%)
Significantly improves cardiovascular endurance. Your body becomes more efficient at using oxygen and transporting nutrients. This is the most commonly used zone for endurance training.
Zone 4: Peak Performance (80-90%)
High-intensity intervals and advanced training. Here you improve speed and power. You should only work in this zone if you already have a solid fitness base.
Zone 5: Maximum (90-100%)
Maximum effort reserved for experienced athletes and short sprints. You shouldn't spend more than a few minutes in this zone.
If you're a beginner, have pre-existing heart conditions, or haven't exercised in a long time, consult with a doctor before training in high-intensity zones (Zone 4 and 5).
How to Measure Your Resting Heart Rate
For the most accurate results with the Karvonen formula, you need to know your resting heart rate:
- Measure upon waking: Before getting out of bed, place two fingers on your wrist or neck.
- Count for 60 seconds: Or count for 15 seconds and multiply by 4.
- Repeat for 3 days: Average the results for better accuracy.
- Normal values: 60-100 BPM for adults; 40-60 BPM for athletes.
Practical Application
| Goal | Recommended Zone | Typical Duration | |------|-----------------|------------------| | Weight loss | Zone 2 (60-70%) | 30-60 minutes | | Endurance | Zone 3 (70-80%) | 20-45 minutes | | Speed | Zone 4 (80-90%) | 5-20 min intervals | | Recovery | Zone 1 (50-60%) | 15-30 minutes |
Not necessarily. The 220 - age formula is a population estimate. Your actual MHR can vary by 10-20 BPM. For more precision, perform a supervised stress test with a healthcare professional.
Different manufacturers may use different formulas or zone definitions. Our calculator uses the Karvonen formula, which is more personalized by considering your resting heart rate.
Yes, you can use the "talk test": if you can talk but not sing, you're in zone 2-3. If talking is difficult, you're in zone 4-5. If you can sing comfortably, you're in zone 1.