Accuracy of "Race Predictor"

So my new Fenix 5S gives me some "race predictor" values. They are fairly fast race times in my case, specially the marathon prediction looks awesome :cool:. But I've never run a marathon (yet).

What do you guys/girls think of these values, how closely do they reflect your current race results?

0 MalcolmLavery over 8 years ago

All mine look pretty spot on apart from the marathon one, which I also have never done. Says 3:11!!! lol :) ....i do my first one this year and will be happy under 4 :)

0 chunkywizard over 8 years ago

The race predictor times are based on your VO2Max. There's a table of all values in the FR620 forum. For me they are all a bit keen. If I take 3 off of my VO2Max then they line up with current PBs

CW

0 MalcolmLavery over 8 years ago

The race predictor times are based on your VO2Max. There's a table of all values in the FR620 forum. For me they are all a bit keen. If I take 3 off of my VO2Max then they line up with current PBs

CW

Im 50 years old and my VO2Max is 52. All predictions are my PBs. Apart from the marathon one obviously. Maybe I can do it in 3:11. Maybe I need to believe lol :)

0 chimpware over 8 years ago

I am also 52, with a slightly lower VO2Max and all Race Predictor Times are also very close to my PBs except the marathon (and I run 1 to 2 a year). The marathon seems to over predict by quite a bit, the rest seems reasonable. I have looked at race predictions for race planning a number of ways including very recently using Stryd Power data and all generally agree except the Garmin VO2Max Marathon number.

0 chunkywizard over 8 years ago

If you look at race predictor websites they all match Garmin in that the marathon seems hopefully optimistic. I think the key point here is you need to train more for a marathon to reach your full potential.

CW

0 FlipStone over 8 years ago

Well, the fact that it predicts a time for my half marathon which is slower then the one I actually ran using the same watch I'm not quite sure what to think ;)

But yeah, believe for me they were actually pretty much in the ballpark... Have to take them with a large grain of salt of course and they do all assume you have put in the necessary training for the related distances I believe.

0 NeilJonesOnline over 8 years ago

Well, the fact that it predicts a time for my half marathon which is slower then the one I actually ran using the same watch I'm not quite sure what to think ;)

But yeah, believe for me they were actually pretty much in the ballpark... Have to take them with a large grain of salt of course and they do all assume you have put in the necessary training for the related distances I believe.

Same here, my predicted 5k time is slower than my regular 5k runs logged on GC. It's the same on Strava, my estimated fastest miles, 5ks, 1/2 marathons etc are in some cases slower than my recent PBs.

0 JRMiler over 8 years ago

For 99% of people, a marathon race prediction will be too optimistic. Only very highly trained athletes are capable of running a marathon that's in line with their aerobic potential.

0 Former Member over 8 years ago

That's the whole point behind these numbers, they are "potential" based on your VO2 Max & training to your maximum potential. It's the second part that trips most people up, including myself. I'm slow, I have never done interval training etc., I often just train by distance or overall pace and my results (or lack of) sadly has always shown... I have a consistent VO2 Max of 43 and here are my (slow) PRS vs. predicted...

5K: 27:06 PR vs. 24:12
10K: 1:01:31 vs. 50:13 (wow)
HM: 2:12:34 vs. 1:51:19 (wow)

While I know the numbers are predictions and may never be achievable (or perhaps could be exceeded) that make it fairly obvious I have something left in the genetic tank if I just trained properly, maybe this year will be the year.