Inaccurate treadmill distance reading

[jirose]

Hi gang, just got finished running a 5k on the treadmill. I selected the exercise treadmill option before I started, and hit the stop button just after I finished. The treadmill itself recorded three miles run in 24 minutes, but the Blaze only recorded 1.7 miles. Anyone know why? This isn't a deal-breaker or anything...I really like the watch, but that's a pretty big disparity.

[04Dbacks]

Yeah-I had an Alta, as well, till it died. I loved it, but used the “One” for the treadmill. Worked well.
Alta was accurate when I jogged outside, unlike the “Blaze.” I thought “upgrading” would really BE “upgrading...” Nope...

Sent from my iPhone

[Rich_Laue]

See my post here.

Basically confirm step count then set the stride. 

Problem solved. 

[Viper13]

I found out that when I run faster on the treadmill is will not show the same milage also. So I just try to run the same amount of time that I run a race in, problem solve. Still show heart rate.

[Rich_Laue]

@Viper13 that makes sense. When the speed of the run changes, the persons stride also changes. This is so that the body can stay over the center of balance. 

[Viper13]

Glad you agree.

[Rich_Laue]

Since the treadmill walk is a virtual walk, the body is not moving, distance will be calculated by math. If Fitbit doesn't know the true stride then the distance will be off. 

[MissZphoto]

I have a Fitbit HR 2 and I do not hold onto the sides and I swing my arms freely. I’ve set my pace manually and made sure my dominant hand was set up correctly. Yet the miles and steps are way off when I walk on the treadmill. If I log my workout manually, it doesn’t count for challenges or anything else. This is very disappointing.  I do 90 minutes at 4.0 every day and so I get 6 miles on my treadmill but only 4.07 miles on my Fitbit. That’s a huge disparity. If it can’t be fixed then at least allow for manually logged workouts to be counted in challenges, etc. 

[Rich_Laue]

Then we will use this formula .

CorrectStride = CurrentStrideSetting " TreadmillDistance /  

Are for simpler math 

Correct stride = CurrentStrideSetting * 1.47

So lets take the stride setting in Fitbit and multiply it by 1.47, this should be your true stride on the treadmill

Please note if the speed is changed .the stride usually will also change. and it most likely not match your stride while on a free walk .

[MissZphoto]

I will try that. Thank you. 

[WJW_3]

I don't know if this problem has been resolved.  When I run, or walk, on the treadmill I lose about 30-40% of the distance.  I don't hold onto the rails.  I still have some loss when I run on the street, but only about 10%.  Arm motion is consistent in both cases. This leads me to believe that the device is sensing impacts and not motion.  This would be consistent with the suggestion that holding your arm close to your body would provide a better count.  

[meresydotes]

@WJW_3 It's not even clear if it's a problem, because distance is a little too squishy. Unless you're using GPS, the distance is just calculated by multiplying the number of steps taken by the stride length. And who really takes exactly the same strides all the time in all circumstances? I started off by doing entire workouts with my Fitbit hand on my body in order to ensure that I knew the correct step count for a typical workout. You are correct, though, in the hand close to the body bit. I stopped using a Blaze a while ago, and I'm using a Versa now, but I've found that the Fitbit really forces me to use what is, for me, perfect form when running on my treadmill (I have arthritis in my knee and the only cardio it wants to do is slow running for some reason). Leaning forward a bit, shoulders back and down, elbows close to sides, only a little swing in my arms. If I deviate, it starts dropping steps. Now, a Fitbit's one real job is counting steps, and it should be able to count all the steps, regardless of whether they're taken with perfect form or not, but here we are.

[Rich_Laue]

There really is nothing for Fitbit to resolve. 

When it comes to treadmills before we can look at the distance, we first have to check the steps counted .

Fitbit has no physical way to measure distance while on a treadmill, at best it can only make an educated guess. 

Steps walked X distance travelled per step = Guess of total distance. 

One problem is physics, as the sipped a person walls at changes, so does their stride. Therefore your stride will depend on the speed of the treadmill and most likely not match the free walk stride. 

As for the way the counter tracks your steps, it is looking at the movement of the arms, not the impact of the feet. 

[WJW_3]

and this is why I'm thinking that the problem is that the accelerometer
(measuring impact) isn't geared to working out on the treadmill. If it, is
indeed, doing what I think it's doing then holding your arm close to your
body increases the level of vibration/impact transfer to the fitbit. Also,
because treadmills are designed to reduce impact forces you get what we're
getting...problematic readings on distance.

As to why it matters: IF you are paying attention to calories (and who
isn't?) then distance matters. You can't rely on a treadmill's estimate of
calories burned, and I am not exactly sanguine about fitbit's accuracy in
this area. That leaves you with doing manual calculations.

I am also using the Blaze...but I'm thinking of moving to a different
product when the unit I have stops working.

I've been running for awhile, and as I don't know you I can't speak to your
experience. If I end up telling you stuff you already know, I apologize.

Your argument about the speed at which a person runs kind of falls apart
when one looks at the dynamics of running. There are two methods of
increasing running speed: Increase the frequency of turnover or increase
stride length. Arguing that increasing one's running speed means that one
MUST have increased one's stride length (and thus created the demonstrated
error) isn't necessarily so. Further to the point, if I run at a 7.25 min
mile pace on the road, and the same pace on the treadmill, and the
conditions are reasonably the same, then the results should remain
consistent within a very narrow range. In other words my stride length
doesn't increase by 30% (or more) on the treadmill just because I'm on the
treadmill.

Moderator edit: merged reply

[Rich_Laue]

ImI'not sure what is meant by impact. The Fitbit has an XYZ sensor that measures acceleration, both positive and negative. 

It is only able to detect changes in speed and direction .

[MikoGenee]

This is not true, because even when walking in the park there is a distance discrepancy. At the gym today, I did 10 miles on the treadmill, but my fitbit ionic registered 8.5 miles. Also, at the Park when I walk the trail, my Samsung Health app on my cellphone registers 10 miles and the fitbit Ionic registers 8.5 miles. Both my fitbit Ionic and my Galaxy Note 9 have built in GPS, so they should read the same, because both traveled with me the SAME distance. Fitbit needs to figure this out!

[Rich_Laue]

But does Samsung health use GPS?

On a treadmill the GPS can not be used, since the user is standing still. So the tracker needs to use the users perceived stride and step count and come up with an estimated distance.

Also as the user changes walking speed, so will their stride change.

[BigBrewer]

I hold the bars on the treadmill so to make it more accurate I take it off wrist and put it in my pocket.... if I think of it.. works pretty well for me!

[Rich_Laue]

@BigBrewer please be cautious and do some research, holding onto the bars can cause damage to the knees and unlearn the art of ballancing making a a person more prone to tripping while outside. Not to mention the other night ways it may damage the body. 

[04Dbacks]

I have vertigo, so, holding onto the bars on the treadmill is better than falling off...

Sent from my iPhone

[Wigs4]

Stride length is the issue. It’s simple to adjust. Here’s the Engineer in me coming through. I ran 3.1miles on the treadmill and my Fitbit said 2.63 miles....16% off. I increased my stride length by 16% and ran it again...now it was 3.02miles on my Fitbit. Tweaked it up a little again and was spot on !  Easier than counting steps/strides !