What workouts can you do to determine each threshold between your heart rate zones?

For example a lactate threshold pace can be determined by running as fast as possible for 30 minutes at a even pace.

Is there something similar for each heart rate threshold and what is it? Right now Im using 90 minute runs to determine any heart rate as being aerobic versus anaerobic, but I dont know how accurate this is nor feel that it is a very good measure. Really need something like this for knowing the threshold between aerobic and fat burning (or easy) zones.

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    A 90 minute run is absolutely aerobic. A 400 meter run is aerobic. About the only runs that could possibly be classified as anaerobic in running are less than 200m and 20 seconds (ish) in length.
    – JohnP
    Commented Feb 8, 2016 at 22:20

3 Answers 3


There is a rule of thumb that anything below 80%HRMax is working within the aerobic zone, whereas above you are heading towards threshold and anaerobic zones (being able to sustain these harder efforts for less and less time). Personally, when training aerobically, I aim for roughly 75% and not higher, even when it comes to hills. There is thought within the coaching communities that if even a slight fraction of the run goes above the aerobic zone threshold, then the aerobic training effect is greatly diminished.

As stated by Julii above, there is no easy way to determine your own heart rate zones, lactate threshold etc, as they are all based on rules of thumb, and averages, and the fact is that everybody reacts differently to the exercise stimulus.

However, there are options available, depending on how keen you are to determine your true zones - a wide number of sports institutions carry out VO2 testing, and with that they will help you determine your heart rates zones. This isn't cheap, however, and I imagine a good 12 months training and you would need to have undergo testing again.

For most casual runners, the algorithms carried out by Garmin, Strava, TomTom etc., will be good enough. Whilst these seem to be arbitrary to begin with (as in fact, they are often just percentages of your HRMax), you can start to adjust them by running by feel - which is something that seems to be lost nowadays with the masses of information available at our wrists.

If you are interested in a slightly more involved method of determining heart rate zones, and/or heart rate zone training, I point you in the direction of Hadd's Approach to Distance Training. If nothing else, it makes for a very good read for the more competitive casual runner, that is looking for a different way to train [I had started following this training method in November, just before I broke my collarbone, but intend to embark on it again!]


I hope this has offered some insight, and I wish you the best of luck!


As Julii alludes to, "zones" are pretty much arbitrary, as you are burning fat as a fuel in all zones, just the percentage to which it contributes to the whole is different for different effort levels. As you get higher in intensity, the more you rely on stored carbohydrates (glucose), and the lower in intensity, the more you rely on fat. They are both still utilized, however, except in very short burst, 100% efforts.

Your best bet is to do a couple of different stress tests to determine your approximate maximum heart rate, and use that with various charts to determine effort and fat utilization.

You can use a few different formulae to approximate your maximum heart rate from run data, but it's not going to be as accurate as a couple of stress tests. Also realize that dehydration, sleep, muscle fatigue, many factors can affect the heart rate to where you think you are working hard but are actually not.


I suppose those are really good questions, because most the formulae just work on rules of thumb & probably we're all too individual for the formulae to work perfectly for everyone reliably.

But the question makes me wonder if the whole idea of zones is just a bit hokey, since the transition points are probably not fixed even for individuals; probably depends on how you feel on the day, even. So then I wonder if it makes more sense to go with "feel" for each zone, rather than relying on precise numbers. There's a description below of what each zone feels like. You'd have to really know yourself to know when you were in each zone, I suppose, so then people go back to inflexible numbers.


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