Marathon / Half-Marathon world record (or how technology makes you faster)

Today was just one of those days when I had scheduled a structured workout, nothing fancy .. using the Stryd half marathon plan as a inspiration, but modelling it in Polar Flow. Nothing unusual here .. though I wish that Polar would be more open and connect with the outside world … I mean syncing with other third party platforms like Training Peaks, Final Surge or Stryd Power Center to make better use of their hardware in a wider context of the training platforms.

Anyway … the plan was simple – 14 mins in power zones 1-2 followed by 3 repeats of (10 min in power zone 3 and 4 mins of recovery in zones 1-2) and last cool down in zones 1-2. When I started the workout I noticed that my zones were way higher than expected … that can only happen if something is wrong with the zone definition and/or the MAP (Critical Power). Since I’m using Stryd (more consistent in distance, pace measuring than GPS), I also use their power values so for simplicity I edited the Running profile to have the MAP value equal to CP (in my case now 297W).

To my surprise, because I don’t remember changing it, the MAP value was the Polar calculated one (450W) which created a mess with all the zones and everything. I updated the value in the Polar Flow mobile app, re-synced the device and started the workout again. I only made some steps and the watch notified me that the first Lap is done (already ?) … I didn’t paid enough attention, it was -4 Celsius and I already spent too much time with redoing the settings, I continued my workout. All the rest of the workout was nice and fine, but when I got back home I was amazed by the fact that the watch was showing that I run 38.75km(?). Then I correlated this with the first automatic lap anomaly and dug a bit deeper.

Yes, the first automatic lap was a mess, somehow Polar measured the first steps as being a long distance … that in theory should come from Stryd (distance, pace, power, cadence) [the references from Polar here and Stryd here] and somehow the communication was weird. Looking in the Polar Flow on web you can see the mess .. the distance measured for the first lap is actually 1.13km but reported 27km, the power also is collected from two streams of data .. one average is 224W (which is close to my reality) and the other is 48W ..

First lap anomaly – you can see the diffs in AVG power and distance

In Stryd Power Center, the data reported by Polar looks also a bit weird, but at least the distance and average values are kind of there.

The same workout reported by Stryd Power Center after collecting it from Polar Flow

At the moment, I don’t know how to edit a workout in Flow .. there might be ways with third party tools, but it’s too complicated so I’ll live with the fact that my distance stats will be unreal and that I was so close to break the world record on marathon distance should I have continued to run for another 3.5 km 🙂

I don’t expect this situation to happen again (I hope not), it didn’t happen until now and I’ve been using my Vantage V2 and Stryd for a while without any issues – this post is only for those who might run into the same situation and think of throwing one of the devices away [you might be more inclined to do so, if that would happen in an official event].

With that, stay healthy and run happy!

PS: with Strava, things are simpler since there is a feature allowing you to “Correct distance” and you’ll show your friends the “real” you, instead of insane values.

Stryd FW 2.1.16 
Polar Vantage V2 - FW 3.1.1

Author: Liviu Nastasa

Passionate about software development, sociology, running...definitely a geek.

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