Cardio Fitness Score accurate?

[emmasawr]

Hi there! I've had the Charge 2 for a few months now (got it back in December) and I've been wondering how accurate the Cardio Fitness score is, and how exactly it is calculated. I currently have a 33 (which is poor for my age) but I don't think I have poor fitness. I'm 19 y/o female and I exercise regularly, as I'm a pretty avid runner. I'm also currently in college living on a big campus, so on a regular day I take at least 10K steps without exercise, and up to 30k with exercise. I run 4-5 times a week, running 3-10 miles per day depending on my training schedule, usually averaging out to 20-35 miles per week. I know the score is based on VO2 max, however, and I do have exercise-induced asthma. My HR to get pretty high during exercise, especially when running up hills (I take a couple of puffs of my inhaler before I go out for runs). Thanks for any insight! 🙂

[WavyDavey]

Hi @emmasawr, take a look at this article on Cardio Fitness Score. I think it will answer your questions.

[Beccabooski]

I had the same problem. I had to go on a run with my Bluetooth on so that my phone was tracking my location for my score to change. Hope that helps:) 

[adetcherRN]

Hi, 

i just thought I would share a bit of insight as a nurse. I believe this score is also taking into account out heart rate. Did you know that ventolin/salbutamol puffers actually increases heart rate? I'm a nurse and also have asthma myself. 

[roxy031]

I also have exercise induced asthma and a higher than average heart rate due to medications I take. My cardio fitness score goes back and forth between 38-39, which is considered "good". I run several times a week (4 miles minimum, 10 mile long runs), and also do strength training, cardio and yoga a few times a week. I consider myself to be in good shape. I think maybe the cardio fitness score is an estimate based on the factors they're evaluating but I've come to believe it doesn't mean much. Mine says it could be increased with more exercise, but I don't possibly see how I could exercise any more without it being my full-time job. It used to bother me that's mine wasn't at least in the "very good" range but I'm chalking it up to a combination of asthma/high heart rate and fitbit just guessing. 

It is interesting that several of us have asthma in common though. 

[Myshkinla]

I don't think the fitness score is necessarily accurate. As far as I can tell, it estimates VO2 max using your resting heart rate, age, and BMI.  This may be a statistically good proxy in general, but it is not the same thing as actually measuring VO2 max. So if your resting heart rate tends to be higher, you will have a lower Fitbit fitness score.  I got my Charge 2 a couple weeks ago, am not in particularly good shape, but I have an "excellent" fitness score for my age range.  I don't think I could run as much you do, however.  That will take me a while. I think the reason my score is high is that I seem to have a naturally low resting heart rate, currently 52. I hope this means I have a strong, "athletic" heart, but I kind of doubt that.  

My current score is 51-55. I set a goal in the app to lose 5 pounds and the app says my Fitness Score will go up if get to that goal weight. This leads me to believe it takes BMI into account too. 

If the asthma medicine makes your heart beat faster or if you have a naturally faster resting heart rate or if your BMI is high, I believe the Fitbit will give you a fairly low Fitness Score.  You sound very fit to me, though. The score is just an educated guess based on a few parameters. 

As someone said, you can probably get a better estimate by tracking your runs with GPS, but that will only be an estimate too because the Charge 2 can't truly measure VO2 Max. You would need to be wearing a mask for that in a lab environment, I think. 

[RenoRichard]

The Fitbit score is only an rough approximation and, as noted above in other replies, seems to be quite highly reliant on resting heart rate. I have a very high BMI (obese), but a low resting heart rate (58 bpm) for an older guy (64 years old), and a very good to excellent cardio score (35-39 for my age) on the Fitbit, but overall I am really only in marginal shape. When it comes to exercise, I bicycle a few times a week and walk on average 5K-8K steps a day. My cardio score is higher than my wife's on the device, although she is a very active ski instructor who gets far more exercise than me. She just has a higher resting heart rate, but all her other stats are better than mine. If your doctor says you are in good shape, be happy and please don't let a tech device's estimate trouble you. 

[StevenADK]

I would say that the score is not good at measuring your fitness compared to another person's, but is reasonably good at measuring your October fitness compared to your June fitness. your 49 would mean little compared to my 49, but it would mean a lot compared to a score of 45 that you recorded months earlier. 

[Paddymaree]

I have run a marathon a few months ago, can run a 5k in 25 mins and it tells me I'm at the bottom of average. Seems like a completely inaccurate waste of time for me.

[Amyleightaco]

Heeeeyyyyy!

I was just reading this thread and was like "I know that girl"!! 

Ccsux4lif! 

❤️ AmyLeigh

[Amanda2020]

I also have exercise induced asthma that seems to have gotten worse recently.  I use an albuterol inhaler which also increases my heart rate, and I don't feel like it helps with my breathing.  Are there any other inhalers or medications others have used that seem to help more? I am currently waiting to get an appointment with my doctor so that I can hopefully get some relief from this. Just looking for other opinions and suggestions from those with similar issues? 

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[PaddyJPG]

Purely for your comparison and not to brag, my Cardio Fitness Score is 56 (Very Good), I'm 25, play 5hrs volleyball per week, and run twice (around 15 - 20mi per week). I average 9,700 steps per day (desk job). My BMI is 23.6 and Resting HR is currently 64 BPM. From reading previous posts, the Fitbit takes all of this into account. I've a Fitbit Blaze, so I run with the GPS on my runs. This also takes into account my HR compared to the pace which I'm running and creates the Cardio Score from that.

[puchatek22ch]

My cardio Fitness Score is absolute opposite of what I would expect. I have fitbit that measures HR for ~2 years. At the beginning when I was less active and my Score was excellent, without activity! I decided to loose weight, which I log into the fitbit. I lost 10 pounds, I started to run, I feel better, I run faster and longer without being tired. My fitbit Fitness score went from excellent to good, and recently to even average <lol> despite of my progress, and lower resting HR! It does not make any sense. I just believe more in what I see when running.

[Paddymaree]

Yeah I know what you mean. I finally got an ionic and thought my score would be more accurate at first it said above average, then I did a 21k/13 mile run at a pretty decent pace, less than 2 hours and my score went down to average. I'm totally confused!

[JohnnyRow]

After you do a connected-GPS run, or it might take a few runs, fitbit uses that data to give a more accurate fitness score.  Before that it is a less accurate estimate.   So if you improve your conditioning and start running, even if you see a drop in your score, it is more accurate after, and it just means it was overestimating your score before it had any data from running.

[WavyDavey]

Some people have reported that longer runs have decreased their score. Do a run on a flat surface for 10-20 minutes, and the score should reset.

[PeteG-1]

I found this thread, trying to figure out how in the heck my Charge2 was actually "measuring" my VO2 max (which I have had done officially, back in the 90's), it was a bit too much to expect.

I think it takes a lot of your resting HRM into account though, and how you "average" during intense exercise.  I'm an avid (ex-racer, but still riding with a fast group, except recently, recovering from a surgery so I'm riding "slow" for a while), and my score has ranged from about 53-67, over 7 months of riding/walking/resting.  Right now it's at 54, and I've had about 3.5 months of "relaxed riding", just now starting to take things back up a notch.

I do have an unusually low resting HRM though, I've ridden pretty much my whole life (except when I used to run, for ski team training, knees are past that now), and it will often "fall" into the upper 40's, sitting around, and seems to average around 53-56, or thereabouts (I'm 51).

There might be something to the "long exercise periods" too, most of my rides are at least 1.5 hours, and will range into 3-5 hours, once ski season is over.  My ride-times are (obviously) a lot longer than runs would be (unless you were an ultra-marathoner, I suppose), for most.

[WavyDavey]

@PeteG-1, when you had the official test done, how long were the working periods?

[PeteG-1]

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wrote:

@PeteG-1, when you had the official test done, how long were the working periods?

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It's been a long time, back in the mid-90's, when I had this tested, a couple of times, I don't even remember my scores (but I do remember I was doing pretty well, even compared to my teammates who were training a lot more "bulk" miles).

I do recall they started out pretty short, maybe 30-45 seconds, and got into the seemingly insane-long range towards the end, maybe 3-4 minutes, with what NEVER seemed like enough recovery ;-]

I still use this quite a bit, say when I've been skiing well into spring cycling season, and need to "catch up" with the fast crew for group rides.  Doing my own approximated VO2 max intervals really boosts my fitness, a LOT, even though it's insanely hard to do "right", when I'm out there solo, it's easy to cheat a bit.  

I basically start low, and work to threshold (intervals), and try to have corresponding recoveries, and do as many as I can at my (approximated) max, and then work my way back down the ladder.  Even a 45-60 minute set of these is incredibly hard, and a great way to get a solid workout, when I'm pressed for time...

I did a cardio stress test for my 40th, and the cardiologist said I had the fitness and heart-health of a 20 year-old, so I guess it hasn't been entirely bad for me, necessarily.

Of course I had to do treadmill, no bike available, which was really tough on me, but I still ran to the end of the test, full-tilt, I was pretty determined ;-]

I'm not a TypeA athlete, really, I ride with enough to know.  I might have been borderline, ski racing in college and road (bike) racing after, but I was truly never in "that crowd".

[OldMike]

In my case I hope it’s right. It’s 53 which if I’m reading the tables right is excellent for a male in his 20’s. I’m a male turning 67 next month. 

My resting heart rate is 52 and peak is 200. I weight 173 and 6ft tall. I’ve been in martial arts for a long time. So for 25 years it’s been high intensity interval training 5 times a week.