No change in my Cardio fitness score

[SunsetRunner]

Hello All,

I use to run outdoor consistently and I was selecting Run on my fitbit charge 2 and I have seen improvement in Cardio fitness score. This was two month back. However, after that I started running on treadmill (By selecting treadmill on my fitbit charge 2), I didn't see any change in my cardio fitness. 

Does cardio fitness score work only when I select run. Can I select run on treadmill.

[HokieHoo]

My understanding is that you have to be connected to GPS while you are selecting run/walking as an activity to affect your cardio fitness score. Thus, running on a treadmill will not affect your cardio fitness score because you are not moving in a route that fitbit could determine your actual distance traveled using GPS. 

GPS varies by device. I have the Charge 2 and it connects to GPS via my phone. I think the Ionic has GPS built in (it doesn't require a phone). So it would also depend on which device you are using how it connects to GPS to determine distance traveled. 

[Dominique]

Actually, running with GPS is for cardio fitness scores expressed as a single number, as opposed to a range. Fitbit can express your cardio fitness score as a range even if you never run, nor use GPS.

[SunsetRunner]

Thanks for your reply. I have selected option Run on fitbit today although I was running on treadmill.  I ran around 4.8KM. Surprisingly, fitbit recorded the distance I ran with starting point as my gym. The app recorded the distance I ran on treadmill and plotted the same on the GPS interface of the app(destination which is around 4.8KM from my gym). Thus, my cardio fitness score also improved. I am not sure whether this is expected behavior.

[SunsetRunner]

Oh is it! So fitbit is constantly tracking by cardio fitness and plotting it. Good to know that. Thanks

[HokieHoo]

If you don't use any GPS, it will calculate an "estimate" based on your resting heart rate and user profile (age, weight, height maybe). If your resting heart rate changes or your weight, it would update your score. If you use GPS it will give you a more accurate number based on your heart rate during your activity. Here is the link to the Cardio Fitness help. When I read it before, I assumed that it wouldn't give a more accurate estimate using a treadmill. When I read it again, now I am not so sure. It doesn't say you can't be on a treadmill. It just says you have to use GPS. So, based on what you are reporting, then I guess it doesn't matter.

[Dominique]

For best results, you should run at full speed for just above 10 minutes outdoors on flat ground. This will be very close to the conditions of Cooper’s test (maximum distance you can run in 12 minutes), one of the "gold standards" for VO2Max.

[Dominique]

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@HokieHoowrote:

If you don't use any GPS, it will calculate an "estimate" based on your resting heart rate and user profile (age, weight, height maybe). If your resting heart rate changes or your weight, it would update your score.

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Yes, it’s definitely the case with weight: when my weight was at its lowest (59-60 kg), cardio fitness score was at its highest (61-64). Now that I have gained weight (63-64 kg), on purpose, it has gone down to 55-59. I don’t feel like my cardio fitness has deteriorated, but carrying 3-5 more kilos could very well mean I’d not be able to run as fast in Cooper’s test, for instance.

[HokieHoo]

@Dominique 

First, let me say that I cannot run "full speed" for 10 minutes. Yikes. That would be painful for me. But I am working on it. Second, thanks for sharing the real-world example of your score going down when you gained weight. My display tells me how much better my cardio fitness score would be if I lost weight. But, even if you cannot run "as fast" as before, I would argue that "speed" and "fitness" are not the same. Before I had done a run with GPS, my fitness score was 39 I think. One run using GPS bumped it down to 32. I was surprised how much it moved down. It is interesting to see how your experience shows the influence of the weight component and mine shows the influence of the GPS/heart rate influence.

The fitness score isn't something I worry too much about, but I do still run with GPS to see if I can get my score to change. My measure of "fitness" is: Can I do the things I want to do? (Which are run, bike, play tennis, hike, kayak, garden, etc.) If I can do those things to the level that I want, then I am meeting my fitness goals. This isn't very scientific but it works for me. 

[Dominique]

By "full speed", I meant the maximum pace you can sustain for about 10 minutes. Obviously, even Usain Bolt cannot sprint at full speed for much more than 200 meters (for him, about 20 seconds). If he had to run for 10 minutes, the pace would be a lot lower. Just don’t jog gently at a pace you could easily keep for 30 minutes.

[justme49]

You just have make sure it is set to GPS or treadmill.... it will update accordingly. 

[Colinm39]

@SunsetRunnerI have found RHR is the clue... In this link we discuss RHR.. and Fitbit stress wearing your Fitbit 24/7 and I have found a correlation between Sleep HR and RHR..  My Cardio is 41-45 with an average RHR of 55..  Excellent for my age.

@Dominiquehas posted this relationship elsewhere