How has the run prediction changed for you?

The last software update (20.26) listed the following change: 

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

For me the prediction was already optimistic before but kind of in range (like a this could be the time if you have the most optimal day), but with the newest change it got even faster it jumped from 41:38 -> 30:29 for 10k and from 3:23 -> 3:18 for a marathon. How has the software update changed your prediction?

  • For me there was hardly any change. My estimated race times are getting gradually slower, and it started before the new version. My VO2Max is dropping, and the watch says my training is unproductive because of it. I blaim it on a minor muscular injury (hip flexors) that the watch does not know about.

  • My VO2max is flat for the same time ... which makes the prediction change even more mysterious.

  • Mine went absolutely nuts: it predicts a faster pace for 10k vs 5k!

    Actual recent PRs: 5k: 23:20, HM 1:51

    Predictions on 11 Sept.: 5k: 21:46, 10k: 46:46, HM: 1:45:58 (reasonable, slightly optimistic)

    Predictions on 12 Sept.: 5k: 20:23, 10k: 38:45(!), HM: 1:36:18 (crazy)

  • I have a Forerunner 265, and I've been using the update since the beta. The race prediction was optimist before, and the update lowered the times even more. I saw as low as 21:16 for a 5k and my PR is 22:47.

    I knew why it was off: my watch thought my max HR was 176 (auto-detect) and the most I've ever seen, at the end of an all-out 5k, was 165 (I use a chest strap.) I was in the middle of training for my first marathon, using the daily suggested workouts, so I didn't want to mess with heart rate settings until that was behind me. It said I could do a marathon in 3:36:00 and I came in about 30 seconds under 4 hours.

    Since then, I've set my HR max to 170 (max 5k HR + 5) and lowered my training volume. It's still optimistic (21:45 5k) but not insanely so any more.