HOW is hill strength calculated?

Derek said:

just the best 10% of hills? 

Being better than 90% of others is not that bad, or is it? Especially assuming that there are huge numbers of trail runners among Garmin users. At trail, the climbs are often very steep and very long. Trails with 1,000 to 10,000 meters of positive denivelation are rather common, so it may be more difficult to get to the same scores on the terrain you described. Being among top 10% without actually doing any trail running looks rather like a success, not a failure, to me.

What is actually your Hill Score? Do you use a HRM chest strap in order to get accurate HR readings? 

Otherwise, some details about the Hill Score are available here 

garmin.com/en-US/garmin-technology/running-science/running-dynamics/hill-score/ 

I didn't mean I was better than 90%, what I was saying does it take MY best 10% hills or ALL my hills or something else?

I use a Stryd + HRM strap.

I'm coming back from a long break (with a bit of sporadic running) so scores are generally poor (I've previously been sub 19min 5k, sub 40min 10k and sub 1h30 HM at 50yo, just 2 years ago)

VO2max, it thinks it's 46 (it still say's that's good.. but I've been a lot fitter)

5k race estimate; it thinks it's 26min, I know from a ton of experience it's around 23min.  I gently cruised a 28min parkrun on Saturday.

I have natural speed, I have to work on my endurance, so most of my runs are slow.. currently 11min/mile over rolling hills to keep the HR at or below 70% of HRmax, that's roughly what works for me..  I got the cue for moving to that sort of training from lab treadmill tests, that's what got me under 19min 5k.

When I do 10second hill sprints for strength I'm touching 3:50/mile up a 7% grade (twice a week), Stryd has my sprint power to weight at about 8W/kg

All my stats (even if they're off) are moving in a positive direction.  At some point I'll throw in a race to see where I am, but I'm looking towards the marathon at some point in '25 or '26..   first I have to rebuild my base.

Endurance score is 5500 (dire, but that's not a surprise given the current low mileage, only 16 miles last week, adding around a mile per week)

Hill score 44

Hill endurance 33

Hill strength 9  - this is the one that's really out of step, thus why I'm asking HOW it's calculated..  is it 2~5minute effort?.. does it penalise you for keeping HR down on the easy runs?,  does it give any kudos for hill sprints (I'm pretty sure it doesn't)

The text about Hill Strength in the previously mentioned article is AFAIK all what is known about the feature:

HILL STRENGTH

Hill strength expresses your ability to run uphill with power. It is about your capacity to attack uphill segments with a mix of high-intensity aerobic and anaerobic efforts. Building hill strength requires regular hard, high-intensity uphill efforts. Keep the relationship between grade and speed in mind as you work to enhance hill strength. Maintaining a slower pace on a steeper hill can require the same effort as a faster pace on a more gradual incline. Focus on consistent hard effort rather than pace. Hard uphill running can be extremely taxing on your body, so be sure to incorporate plenty of recovery time between efforts.

Maybe this is example of odd metric. But people want numbers, colors :-). I´m recreational runner, about 7-11km (70-150m climbed) 3 to 4-times per week and I got:

Hill score 44

Hill endurance 21

Hill strength 22

It seems, that you are too good for this metric :-). Try to run some hills easy in zone2.

RE: Since the metrics is dependent on the Running Power, I would also try some hill runs without the Stryd

Now that really IS a thought. Stryd do give lower power numbers than garmin, IIRC about 30% or more lower, which could explain the wayward stat..  I'll give it a try and report back.

Derek said:

Stryd do give lower power numbers than garmin

To be pedantic, Stryde uses a different method to estimate running power that results in different outcomes to Garmin. This would be true of most power estimates provided from different sources. If IRC there is a toggle somewhere to select to use 3rd party power but I’m old so I could be wrong!

Since the metrics is dependent on the Running Power, I would also try some hill runs without the Stryd, using the native Running Power of the watch (or of the strap, if it is the HRM-Pro). I am not telling Garmin is more accurate than Stryd, but Stryd may be using a different algorithm leading to results skewing other metrics.

Contrary to popular misconception, which has been repeated in the forums over and over again, Garmin will never use a third party power sensor for any built-in running power-related features.

Yes, the activity running power source setting has the following options: Smart Mode [accessory or wrist], Accessory Only and Wrist Only. But in this context, accessory only ever refers to Garmin accessories: e.g. HRM-RUN chest strap, running dynamics pod (RD-POD).

But don't take my word for it. You can verify or disprove what I said as follows:

- set the running power source to Accessory Only in your Run activity

- pair your Stryd (or other third-party running power sensor) as a power meter. Note that when you do so, the sensor is actually being paired a cycling power meter, since there is no standard ANT+ support for running power meters

- add the built-in [running] power field to your activity

- if testing with Stryd, add the Stryd Zones CIQ data field to your activity. This will be a good way to demonstrate that the manufacturer's data field is ofc able to read power from the Stryd sensor, even if the built-in power data field [and other power-related features] will not read power from the Stryd

- do not pair a Garmin chest strap or RD-POD to your watch. If one is already paired, temporarily disable the connection for this test

After doing all of the above, you should be confident that:

- Garmin running power will *not* come from the wrist

- Garmin running power will *not* come from a Garmin accessory

- The only possible source for Garmin running power must be your Stryd (or other 3rd-party sensor)

But again, I'm fairly certain that Garmin will never use a 3rd party sensor for built-in running power.

If I'm right, then the built-in power field will display --, indicating that there's no power value at all, and therefore no running power source.

If I'm wrong, then the built-in power field will display a number [even if it's zero], and that number should be equal to what the Stryd Zones data field is displaying.

I just did this test on my watch, and it indicates that I'm right about this. Every time I've done this test in the past, I've had the same results, too. But I'd love to hear if anyone else sees something different.

So what that means is the presence or absence of Stryd power in itself should never affect any Garmin metrics. (This is separate from whether built-in running power is enabled or disabled ofc, and it's separate from the running power source setting. For example, if you happen to completely disable built-in running power bc you are using Stryd, then it's conceivable that would lead to different results than if you had built-in running power enabled, but only bc of the presence or absence of built-in running power.)

[Note to Garmin / mods: I had to edit this post like 50 times for it to be finally accepted by the forum, in its entirety]

To be pedantic, Stryde uses a different method to estimate running power that results in different outcomes to Garmin.

To be even more pedantic, there's no well-accepted definition for running power [*], so it's completely unsurprising that different vendors (e.g. Garmin, Stryd, Apple and COROS) would produce different values for running power estimates, even going beyond the fact that these are just estimates and not measurements.

As there's apparently no objective standard to adhere to, it seems impossible to say which of the estimates/algorithms is more "correct". Ofc, it makes a lot of sense that if you're using Garmin running power features (including any metrics which are based on Garmin running power), you would want to stick with Garmin running power estimates. And indeed, Garmin won't accept running power data from 3rd-party sensors.

In contrast, cycling power has an objective definition, and cycling power meters actually measure power, as opposed to estimating it.

[*]

www.dcrainmaker.com/.../running-comparison-garmin.html

The challenge with running power is that scientists disagree about what aspects should be included. Specifically, whether or not the elastic recoil effect should be included within the power figures. And thus, whether or how to account for it. The super-short oversimplified version is that Garmin and Polar include the elastic recoil/rebound output in their power numbers, whereas Stryd doesn’t (and it doesn’t appear Apple does either). There are pros and cons to both methods, and all these companies will show off results on a force-plate treadmill showing alignment and their righteousness. But again, they each differ on what they want to account for.

pmc.ncbi.nlm.nih.gov/.../

A variety of methods for measuring or estimating running power have been explored. In these methods different assumptions were made when calculating power and the power calculations required ground reaction force data or kinematic data for input. Due to these differences in assumptions and input data, the values resulting from the power calculations varied widely. A well-accepted definition of running power does not exist. However, a few recent wearables for runners include estimates of running power.

I did this text the next day my Enduro 2. And it worked the way  as you surmised.

I also tested the short term power values of Stryd and wrist based, side by side using a fake weight for Stryd, and the watch was more reactive, both at acceleration an deceleration.

Note: forums.garmin.com/.../1854842