Heart Rate Zone Calculator, Fat Burn, Cardio & Peak Training Zones

What Each Zone Does

• Zone 1 (Recovery): Very light effort. Used for warm-ups, cool-downs, and recovery between hard workouts. Builds the foundation of aerobic fitness without fatigue.
• Zone 2 (Fat Burn): Comfortable effort where you can hold a full conversation. Builds aerobic base, improves fat metabolism, and is sustainable for long durations. This is where most endurance training should occur.
• Zone 3 (Aerobic): Moderate effort, slightly harder to hold a conversation. Improves overall cardiovascular efficiency and is the transition zone between easy and hard training.
• Zone 4 (Anaerobic): Hard effort, can only speak in short phrases. Builds lactate threshold, increases speed and power. Typically sustained for 10-30 minutes in intervals.
• Zone 5 (VO2 Max): All-out effort, cannot speak. Builds maximum cardiovascular capacity. Only sustainable for 30 seconds to 3 minutes. Used sparingly in training.

Measuring Resting Heart Rate

For the most accurate resting heart rate:

• Measure first thing in the morning before getting out of bed
• Use a chest strap or pulse oximeter for accuracy
• Take readings for 3-5 days and use the average
• Avoid caffeine and alcohol the evening before

Training by Goal

• Weight loss: Focus on Zones 2-3 with occasional Zone 4 intervals
• Endurance: Spend 80% of time in Zones 1-2, 20% in Zones 3-4
• Performance: Structured mix of all zones with emphasis on Zone 4-5 intervals and Zone 1-2 recovery
• General health: 150 minutes per week in Zones 2-3

Standard vs. Karvonen Method

The Standard method calculates zones as simple percentages of max heart rate (220 - age). It is simpler but less personalized.

The Karvonen method uses your heart rate reserve (max HR minus resting HR) and adds back your resting HR. This produces more accurate zones because it accounts for your individual fitness level. A lower resting heart rate generally indicates better cardiovascular fitness.

Disclaimer: This calculator provides estimates for informational purposes only. Consult your healthcare provider before starting a new exercise program, especially if you have a heart condition or other health concerns.