There are quite a few methods used to calculate your zone 2 training zone, which builds optimal aerobic capacity.
The 4 methods I’ve tried are:
Calculate your zone 2 training zone using percentage of Maximum heart rate
This method calculates your Zone 2 as 60% to 70% of your maximum hear rate. You obviously need to know what your maximum heart rate is for this calculation. There are a number of tests you can do to work this out. I use the the max heart rate I’ve seen on my heart rate monitor during very hard interval training.
For most of my training over many years I’ve used this method. The highest I’ve seen on my heart rate monitor in the last year is 191 bpm (beats per minute). Following this method my Zone 2 HR would be 115bpm to 134bpm.
Calculate your zone 2 training zone using percentage of Anaerobic Threshold
Anaerobic Threshold is the point at which the lactate in the blood equals the amount being produced. Above this rate the body can’t clear lactate as quickly as it’s produced. This is why Anaerobic Threshold is also known as Lactate Threshold.
To establish your Anaerobic Threshold you can do a best (but steady) effort for 30 minutes on a bike or run. Then take your average heart rate over the last 20 minutes as your Anaerobic Threshold.
To calculate your Zone 2, multiply your Anaerobic Threshold by 85% to 89%
I did a full 30 min best effort on an indoor trainer and came out with an average heart rate of 153bpm. Using this as my Anaerobic Threshold my Zone 2 would be 130 to 136bpm
Calculate your zone 2 training zone using the MAF Method
The MAF 180 formular calculation subtracts your age from 180bpm. Subtract 5 bpm if in the last year you’ve been injured, had minor infections or are overfat. If you’ve had a major illness, are in rehab, on regular medication or chronically overtrained subtract 10.
If you’ve been training regularly for more than two years, add 5.
My calculation would be 124bpm (180 minus 51 years minus 5.
The Talk Test
This is a simple but amazingly accurate method that anyone can do. Once warmed up, slowly increase exercise intensity while monitoring your hear rate. If you can talk and hold a conversation, but are slightly laboured, you are likely in Zone 2. If you can talk but struggle to complete a sentence, you have probably exceeded Zone 2.
I carried out this test on an indoor training, after warming up for 10 mins I ramped up 10 watts at a time and held at this pace for 10 mins. When at 155 Watts I could talk easily and my heart rate was 122bpm. At 165 watts talking was slightly laboured, heart rate was 133bpm. Then at 175 watts heart rate wat 148bpm and my conversation was really laboured. From this test I assume my optimal heart rate is 133bpm
Summary
All of the test above have their own merit and based on my results all broadly fall into the same ballpark.
| Method | Zone 2 |
| % Maximum Heart Rate | 115 bpm to 134 bpm |
| % Anaerobic Threshold | 130 bpm to 136 bpm |
| MAF Method | 124 bpm |
| Talk Test | 133 bpm |
To get the most out of your Zone 2 training you need to try and not exceed your Anaerobic Threshold. I err on the side of caution when training at Zone 2 and take the lower of the levels as the ceiling with which to work below. I try to keep my Zone 2 training at 125bpm.
Interestingly, I recently did a sub-optimal VO2Max ramp test in a test facility. It’s described as sub-optimal because it only takes you just above Anaerobic Threshold then uses that to calculate heart rate zones. The test results showed my Anaerobic Threshold to be 135 bpm and my Zone 2 to be 115 bpm to 126 bpm.
Below is a graph from the test, you can see this shows my aerobic threshold (green vertical line) to be roughly 115bpm and my Aerobic Threshold (purple vertical line) to be at 135bpm. In my case it looks like the Talk Test, percentage of max heart rate and the MAF Test are all good methods, giving fairly accurate results.
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