Find your maximum heart rate: 220 minus your age
Choose your target intensity: 50% to 85% of your maximum heart rate
Multiply your maximum heart rate by 0.50 for the lower target
Multiply your maximum heart rate by 0.85 for the upper target
Use the result as your target heart rate range
Example: age 30
Maximum heart rate: 220 – 30 = 190
Target range: 190 × 0.50 = 95 bpm
Target range: 190 × 0.85 = 162 bpm
Heart rate zone: 95 to 162 bpm