20.26 firmware sudden race predictor and endurance score spike

Hi all,

955 user here just updated to 20.26 yesterday (rest day), first run after upgrade today. Normal 12-13km VO2 max mile repeats session. Got back and watch showing absolutely nonsense dive in race prediction times. 5km time dived from 18:09-ish to 17:22. Marathon time dive from 3:01:00-ish to 2:53:52.

These numbers are ridiculous and it’s ruined any sense of achievement I’ve gotten by slowly improving these times during my recent marathon training block. I know these aren’t super accurate anyway but that’s beside the point; they were at least stable before.

Is anyone else experiencing this problem?

I must say, first the optical HR sensor issue and now this? Are you actively trying to drive your customers away, Garmin?

Edit: for context my current half PB is 1:27 and change and 3:20:xx marathon, 37:55 10km. All from a few years back but fitness very similar in this block, same reported VO2 max figure. Recent half training run have been slower and probably not at sub 38 10km pace either but prediction is 36:40 which is nonsense.

Endurance score jumped a huge amount too, fwiw. Somewhere in the neighbourhood of 400 points.

- Seriously annoyed runner

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0 mastriae 2 months ago

I have the same issue. Similarly, I didn't put much stock in the numbers themselves, but enjoyed seeing the steady progress. Sudden changes undercut the feeling of accomplishment.

0 Grumpy from dawn till dusk 2 months ago in reply to mastriae

It is intentional, read the release notes:

“Improvements to race time predictions based on fitness level and recent efforts.“

https://forums.garmin.com/sports-fitness/running-multisport/f/forerunner-955-series/383109/forerunner-955-software-version-20-26---20-phased-rollout

For me, mostly the 5K value chanced noticeable, the others not so much.

0 rundad86 2 months ago in reply to Grumpy from dawn till dusk

I know it’s intentional. I was reporting it because it’s now wildly inaccurate vs only a little inaccurate before.

I see one resolved report of it returning to 'normal' a few days after spiking the other way (worse times) on the 255 forum. Here's hoping it does the same here in a few days' time.

0 Saro 2 months ago

Same here, the predictions for all the distances suddenly jumped to extremely optimistic values

0 Miky 2 months ago

Before this release race predictions were optimistic.

Now they are simply fool!

My PB are 18:21 for 5k, 38:24 for 10k and 1:25:36 on HM done 1 year ago at 47yo

0 3333981 2 months ago

Same here - I set a 5k PB a few weeks ago of ~18 mins, when my watch predicted high 17s. Suddenly I’m apparently capable of 15:xx which is just ridiculous. Really frustrating regression from this update that renders that feature completely useless

0 2087417 2 months ago

I raced a 5k in 17:30 last week. Garmin predicted mid 18's. Now Garmin predicts 17:01. Same vo2max of 58.

0 965guy 2 months ago

Lol. I was just going to create a post stating the exact opposite reaction to the same problem.

The update came in as I synced after my morning run. On my second run today I noticed an improvement from 2:56 to 2:48 in the marathon which is a huge jump in one reading, especially considering I've run 2:38.

I've never ever put much stock in this, and in fact I've had my fastest race predictions only when I took 3 months off for injury in the last year (why does running zero for 3 months improve fitness? was I THAT over-trained? )

- seriously happy runner

For real though I really don't put much stock in these numbers. It's a meme between my friends as who can beat their marathon predictor the most. On average we're 20-30 minutes faster than the old predictor.

0 965guy 2 months ago in reply to Miky

Myself and many of my friends are dramatically faster than Garmin, so this is much better for us. We often joked say we ran a 34:xx 10km and garmin would say'...err. 37? 38?' we'd say, 'what, like right now? post run?'

0 rundad86 2 months ago in reply to 965guy

lol. Yeah, I definitely don’t put value in it either. Hilarious that it was underestimating your marathon times so badly before when lots of us probably had the opposite. You’re not doing a 3 month taper? You’re doing it wrong. You’ll probably break the world record once you correct that hahaha. Clearly not a great algorithm.

Tbh I only checked it to see what it was estimating approaching the last marathon I did, as sort of a comparison to the same point in this training block. Maybe it’s just using VO2 and not factoring in that I’m probably an inefficient runner at my VO2 max

Yeah, seriously annoyed maybe over the top. Definitely annoyed by the OHR mess though. That’s a joke and they should be fixing that