Karvonen Formula (Recommended – Uses Resting HR)
Standard Formula (Percentage of Max HR Only)
Your Personalized Training Zones
Zone
Intensity
Range (BPM)
Purpose
How to Calculate Your Heart Rate Zones for Running
Understanding your heart rate (HR) zones is essential for any runner looking to train efficiently. Whether you are training for your first 5K or chasing a Boston Qualifying marathon time, running at the correct intensity ensures you are stimulating the right physiological systems while minimizing the risk of overtraining.
The Karvonen Formula vs. Standard Percentages
Most basic calculators use the standard formula (220 – Age) to determine your maximum heart rate and then apply simple percentages. However, the Karvonen Formula is widely considered more accurate for athletes because it incorporates your Heart Rate Reserve (HRR). HRR is the difference between your maximum heart rate and your resting heart rate. By including your resting pulse, the formula accounts for your current cardiovascular fitness level.
The Five Running Zones Explained
Zone 1: Very Light (50-60%) – Used for warm-ups, cool-downs, and active recovery days. You should be able to hold a full conversation easily.
Zone 2: Light/Aerobic (60-70%) – The "fat-burning" zone. This is where most of your base mileage should occur. It builds endurance and strengthens the heart.
Zone 3: Moderate/Tempo (70-80%) – Improves aerobic power and efficiency. This pace is "comfortably hard."
Zone 4: Hard/Threshold (80-90%) – Enhances anaerobic capacity and raises your lactate threshold. Your breathing will be heavy, and you can only speak in short phrases.
Zone 5: Maximum (90-100%) – Used for high-intensity intervals and sprints. This effort is only sustainable for very short bursts.
Calculation Example
Imagine a 30-year-old runner with a resting heart rate of 60 BPM. Using the Tanaka formula for a more precise Max HR estimate (208 – 0.7 * Age), their estimated Max HR is 187 BPM.
Using the Karvonen method for Zone 2 (60% to 70%):