HADD's 2400m test - big difference between HR zones

I don't understand what the HADD test does. Taking pace at 10-beat intervals is such a wide range as to be nearly useless.

If the purpose is to determine LTHR, then the Joe Friel method would be a better approach, in my opinion. It's also less strenuous and can determine LTHR within a beat or so if done correctly. Here it is in a nutshell.

Warm up for a couple of miles.

Without stopping (so your HR doesn't drop), start your HRM and run for 30 minutes at the pace you would run in a 1-hour race. Take a split at the 10, 20, and 30 minute finish. (You can take more splits if you like.)

Disregard average HR over the first ten minutes. Look at your HR over the last 20 minutes of this 30-minute run. Your HR should be relatively consistent over the last 20 minutes.

If your results were something like 147, 155, 156. Then your LTHR is 156, give or take a beat.

If your results were more like 147, 155, 167, then you ran too fast and went anaerobic. You have to take a few rest days and repeat the test.

Once you have your LTHR, it's your maximum tempo and LT run HR.

Your slow pace is 30-45 beats slower.

You don't need to know Max HR to use the Friel method.

As a side note, HR vs time doesn't give a linear progression of speed. HR increases linearly with speed up to the LTHR. After LTHR, HR increases faster than speed until it plateaus at/near Max HR. To see the deflection caused by running faster than LTHR, the chart would have to be HR vs speed (in mph, kph, m/sec).

fisky wrote:I don't understand what the HADD test does. Taking pace at 10-beat intervals is such a wide range as to be nearly useless.

Hadd's idea was that it would tell you something about how you respond to variations in intensity. Something, which LTHR, VO2Max, etc. doesn't. This could then be used to analyse your aerobic base fitness.

However, I think Hadd's conclusions from the test were based on a false premise. He would look into how much the pace changed for each heart rate step, and when he saw a large pace difference at low heart rate, he would interpret it as low base aerobic fitness.

The reason that I think this premise was false is that it fails to consider the linear dependency between speed and HR, which you and I have both pointed out in this thread.

I once converted his Joe example paces into speeds and - at least as I remember it - the apparently non-linear pace differences could be fully explained by linear speed changes. And likewise, Joe's later improvements could be fully explained by the linear HR/speed trend moving down.

What I have often wondered is, if given a large set of Hadd test data from various runners with various base aerobic fitness, would it be possible to plot their results in a diagram with speed on the horisontal axis and HR on the vertical axis, find the linear trend, and then draw valid conclusions from the slope and Y intercept of that trend?

(*: Above LTHR, the dependency can actually go both ways or just continue! That is a well-known weakness of the Conconi test.)

fisky wrote:

..
If the purpose is to determine LTHR, then the Joe Friel method would be a better approach, in my opinion. It's also less strenuous and can determine LTHR within a beat or so if done correctly. Here it is in a nutshell.Warm up for a couple of miles.Without stopping (so your HR doesn't drop), start your HRM and run for 30 minutes at the pace you would run in a 1-hour race.

I believe Joe Friel says 30 minutes "all out": https://joefrielsblog.com/determining-your-lthr/ .. Which one is it, or would you say it's the same thing?

Also, the confusion will happen, I think, when you don't know your current fitness and try to run either, "30 min all out", or "30 min for 1-hour race pace"....

Maybe you should do the test several times to find your true LHTR, or at least as close as possible, as the test results may differ?

However, I think Hadd's conclusions from the test were based on a false premise. He would look into how much the pace changed for each heart rate step, and when he saw a large pace difference at low heart rate, he would interpret it as low base aerobic fitness.

Interesting! Do your conclusions change anything about the athletes aerobic fitness, and how to look at it? Is there another, better way to track improvements over time?

Hoek wrote:Do your conclusions change anything about the athletes aerobic fitness, and how to look at it? Is there another, better way to track improvements over time?

I lack the data material to draw any conclusions of my own. I only had the data from his example, which was enough to see the assumption error I pointed out.

Anyway, I think the test itself - or any other kind of ramped test following a constant protocol - is interesting.

But to get a true image, I would plot the results in a HR vs. Speed diagram instead of a HR vs. Pace diagram, and then I would watch the development of that curve - does the slope decrease, and does the intercept point on the vertical axis move down? Both would be sign of improvement, but as I wrote, I don't know if one improving before the other would say anything about your aerobic base.

(I should probably add that I am an engineer and number cruncher, with absolutely nothing running related on my CV.)

It appears that Friel has changed his approach from the former, as I described it, to the latter of the average HR over a 30-min all-out run.

Perhaps it's because the 30-minute "all-out" test is one and done. You just take the average HR. There's nothing to mess up. Whereas, the 30-min @ 1-hour race pace would result in some (many? most?) runners going too hard, getting invalid results, and thus having to repeat the test.

Regardless, you're going to get an exact number using Friel's method. Now, LTHR probably varies a couple of beats depending on heat, humidity, overtraining, etc, but it's still a precise number to use for your training until you need to tweet it up or down a beat or so.

Typo "tweek" it up or down...

Thanks sincerely, all you guys! You've straightened out a few question marks for me on these extremely interesting, but not always so simple and clear, subjects!

Hoek wrote:

However, I think Hadd's conclusions from the test were based on a false premise. He would look into how much the pace changed for each heart rate step, and when he saw a large pace difference at low heart rate, he would interpret it as low base aerobic fitness.

Interesting! Do your conclusions change anything about the athletes aerobic fitness, and how to look at it? Is there another, better way to track improvements over time?

There is a lot of very scientific approaches discussed here. I have a much simpler approach. I like to run a lot of long tempos similar to what Hadd prescribes only I do them by feel rather than by the HRM. Interestingly enough, my HR almost always falls in the ranges Hadd prescribed Joe unless I decide to "release the hounds" at the end of the tempo.

Anyway, how do I track fitness improvements? During one of those long tempos, I will run up until the point that my breathing starts to shift gears and then drop it down a notch. Basically, as fast as I can without breathing hard and as slow as needed to avoid getting out of breath. As long as my fitness is improving, my pace at this effort gets faster. It's that simple. A few years ago, this pace was about 7:30 and today it is about 6:10.

BHViking wrote:

There is a lot of very scientific approaches discussed here.

Not really. It is simple math:

If Y is a linear function of X, then Y can't also be a linear function of 1/X.

Hadd's problem was that he tried to find linearity in 1/X.