Why you shouldn't wear your One on your ankle or foot

[Mary]

I know a lot of people like to wear their One on their shoe or ankle, to capture more steps or capture cycling 'steps'.  I figured this was giving them inflated calorie burn data so decided to do a little test today.  

I did the same walk today with my One on my shoe as I did Thurs. with it on my torso.  My calorie burn was over double with it on my shoe.  On my torso, it was around 5 calories/minute, on my shoe, around 12 calories/minute.  The green bars below are walking with it on my shoe.  The yellow ones on my torso, just a short sample from today.  The yellow ones are the more accurate values, which is what you'd expect.  The One assigns calories based on the motion it detects assuming it's worn on the torso.  If you wear it on your ankle or foot for long or often, I wouldn't trust that your calorie burn is anywhere near as high as it says.  For just a 40 minute walk, it credits me almost 300 more calories on my foot than my torso (187 vs. 476).  If I wore it all day on my foot and tried to eat those extra calories, I would gain weight fairly quickly.  

[Colinm39]

@MaryYou have replicated my tests from last year and it's good to add to the research and confirm. I did the tests with a pair of Fitbits, one on the waist and the other on the ankle and next day I reversed the Fitbits. I also did the tests waist and wrist. Recently I ran tests on a stationary bike, and the further the Fitbit was from the waist the calories increased. The positions were, mid thigh, top of knee and ankle.

Here are the results for the ankle and waist while walking

[Mary]

Wow, Colin, that's some serious data!  I was proud of myself for posting a simple screen grab.  

[Colinm39]

@Mary I'm glad someone else has come up with the same result as I did and now we have it in the new Community.

He There were so many suggestions in the old forums and because I happened to have my superglued Classic and my insurance policy Ultra I decided to test.  I had already tested the pair for step accuracy so I knew the results would be accurate. 

I will post the stationary bike link in a few hours.  

[Colinm39]

Stationary Bike tests for ankle and knee mounting of a clip on Fitbit

I have just finished some more testing, and if you are strongly into your calories I would test your relevant Fitbit and compare calories on a walk with it mounted where Fitbit suggest, and on the areas where you feel it will help you.

The clip on Fitbits are extremely accurate with steps whether it be worn on the ankle or waist, but as I have mentioned in many posts the calorie burn will nearly double on the ankle mounting.

Because I have a pair of Fitbits it allows me to test simultaneously and then swap the Fitbits so I get two tests and I was surprised by the cycling results so the inbuilt accelerometer has other "tricks" other than impact.

This set of tests which embraced the ankle mounting and waist mounting on both walking and stationary bike. I also included knee mounting on the stationary bike. I kept the speed on the stationary bike at my walking Heart Rate Monitor speed, about 72-75% of maxHR so that we can have accurate comparative results. I doubled the single cadence on the bike because it was 62 and 63 steps/minute on the right leg. But, the calories were as generated by the Tracker.

The Fitbits used were the Classic and Ultra which are both accurate on previous tests and as you can see from the walking there was only 3 steps different overall and I keep both updated with my activities and wear them both. Results were.

Activity....... Cals/5 mins... Steps/Minute

Walk Ankle........57..................121 *

Bike Ankle.........48..................126 **

Bike Knee.........53..................126

Bike Waist........19..................124 **

Walk Waist.......35..................121 *

Bike HRM..........35

Walk HRM.........34

* 6212 and 6215 steps respectively.

** The waist mounting on the bike was nestled in where your waist and groin meet and it detected the step count perfectly, but the "effort" at 19 calories/5 minutes was nearly sedentary. Both the knee and the waist mounting showed significant difference, but not the near doubling effect of ankle walking because of the lack of impact but still significantly higher.

The 34 calories walking and the HRM 35 calories are spot on giving me the assurance of the walking speed @ 3.8+ mph (5.8+ kmh) and titled VAM in the activities database. So you are comparing the 34 calories/5 minutes to the other activities.

CFM October 5th 2013 results.

[Pril]

AMAZING data,, knowing I want to do this as well. I feel everyone is different and I"m a hard walker. so it has me thinking more steps. 103 step difference to me isn't to bad. I don't worry about the calories burn personaly I dont pay much attention to all that jazz. I need to worry about a healthy heart and activity more then calorie intake as I eat realtively healthy. 

Is this done with the  fitbit one? 

I am going to do the same test and with different equipment. I don't know why it motivates me to do more and I apperciate this post due to the added motiviation it gives me. 

Thank you! 

[Colinm39]

@Pril@MaryMary's test was done with a One, mine was done with an Ultra and a Classic in unison. The Classic has been replaced with a One, and I have checked that they are accurate on steps and calories as a pair so I would expect the same results.

[SunsetRunner]

I'm thinking the reason the hip wearing numbers showed accurate step count and not calories is because the SPEED at which the fitbit was moving????? Made the 121 steps count as 'lightly active', whereas when it was lower on your leg it had greater speed with the exaggerated movements of a pedal cycle ???