Cardio fitness score drops overnight

[Sesquiterpene]

Hello!

I have had my Charge5 for almost 2 years, doing lots of activity including multiple runs (30 to 70 min) per week. I always had GPS turned on, and the device usually uses my phone's GPS. My cardio score has always been a range of 58 to 62, seldomly shifting the range one point up or down.

In the last weeks I have been running a lot. Nothing changed. Last week I did another run in the morning. Nothing changed. Then in the afternoon I tried to do a different run - I ran about 15 min barefoot on the beach. Running on the sand was obviously harder but I ended up running rather fast. I didn't take my phone so I used the device's GPS. The signal broke at some point, and it is now recorded in the app without GPS tracking but at a speed that is higher than my average.

That evening, my cardio fitness score dropped by almost 10 points to 51. 

I since did a few of my "standard" runs (40 min, GPS via phone) and it no stabilized on 52.

How could it be that a single "weird" run, that was actually fast but lost GPS signal (a) led to a permanent drop in the cardio fitness score; and (b) after almost 2 years, changed the estimate from a range to a single point estimate.

This behavior seems completely erratic and weird to me. Anyone else noticed something similar?

Thanks!

[Ingrjc1]

Same thing for me happened on 7/23.  Mine went from 63 to 67 to 50 literally overnight.  Still at 50 this morning also.  Not sure what is going on, but it does not even give a range now, just a single score of "50". 

Interesting that I also took a very light run on the evening of 7/23.  My Charge 5 was trying to log it as a workout, but I kept stopping the tracking.  Odd.  maybe this has something to do with the reset, but I worked out really hard the last two days with two hours of basketball and recorded over 20K steps each day. 

Not that this score means that much, but I was taking pride on moving it higher and higher over the past several months.  Mine has never been as low as 50.  I might hard reset my Charge 5 to see if that has any effect.

[Sesquiterpene]

Thanks! Sounds suspicuosly similar and it's clearly a malfunction. 

I agree that the scores in the end don't mean that much; but in the end, that's why we're using these devices - to get an idea and a record of our activity. If the numbers aren't to be trusted at all, I might as well drop it and return to the Casio I had when I was 8.

Please update if a hard reset improved anything.