The primary benefit of Zone 2 training is that it builds aerobic base and endurance. Increased aerobic capacity enhances your ability to sustain a sub-threshold pace for a longer period of time. In conjunction with higher intensity efforts, Zone 2 is the foundation from which to begin to build threshold fitness.
To get an accurate value for your Zone 2 Heart Rate Range, use these calculations:
Calculate your HRR (Heart Rate Reserve)
220 – Your Age – RHR (Resting Heart Rate)
Calculate your Zone 2 Heart Rate Range
Minimum: RHR + 0.5(HRR)
Maximum: RHR + 0.75(HRR)
If you are 40 years old, subtract that number from 220. Your maximum heart rate is 180.
Then, subtract your resting heart rate (you can measure it using a heart rate device).
If, for example it’s 80, your heart rate reserve is 100 beats per minute. (180 – 80)
The Zone 2 range will lie between 50 and 75 percent of your heart-rate reserve.
Using the example above, 50 percent of 100 beats per minute is 50. And 75 percent of 100 is 75.
Next, add your resting heart rate to both numbers: 50 + 80 = 130 and 75 + 80 = 155.
Therefore, your Zone 2 heart rate range is between 130 and 155 beats per minute.