Do you use HR to monitor you effort? If so, the Karvonen Formula will help you get more accurate HR values.
To determine target heart rate using the Karvonen formula
• Subtract age from 220 to get Maximum Attained Heart Rate (MAHR)
• Subtract Resting Heart Rate (RHR) from MAHR to get Heart Rate Reserve (HRR)
• Multiply HRR by exercise intensity and then add RHR to get Target Heart Rate (THR)
Take your Resting Heart Rate before getting out of bed in the morning for three to five consecutive days and use the average in this calculation.
The Karvonen method for determining training heart rate is superior to the traditional method of simply subtracting age from 220 and then multiplying by the level of intensity of the workout to determine your target heart rate.
The Karvonen formula takes into account resting heart rate to determine the Heart Rate Reserve. Since resting heart rate is reduced as the level of conditioning improves the Karvonen formula is a more accurate method for determining Training Heart Rate (THR). As resting heart rate goes down the Heart Rate Reserve (HRR) – the difference between Resting Heart Rate and Maximum Heart Rate – increases, and is a reflection of the heart’s increased efficiency in pumping blood.
For example, use the Karvonen formula for a 38-year old client with a Resting Heart Rate of 52.
• 220 – 38 = 182 MAHR
• 182 – 52 = 130 HRR
• 130 x 80% = 104 + 52 = 156 THR
For the same person, look at the Target Heart Rate using the old school, simple method.
• 220 – 40 = 180 MAHR
• 180 x 80% = 144 THR
Using the traditional method for determining Target Heart Rate puts you well below your capacity for work and using this lower heart rate as a guide results in a less effective and efficient workout.