Logging non-step, non-distance exercise in FitBit?

sarahmichelef

I've been using RunKeeper for ages (long before I had a fitbit) to log my actual exercise and have had both RK and FB syncing to MFP. That setup works well. But lately RK has been wonky for me so I have been experimenting with logging my exercise in FB.

Which brings us to this morning. I logged my 45 minute spin class as no distance (the spin bikes at my gym don't have any sort of data output) and it gave me a whopping 140 calories (I'm 5'4", 170). That's less than I would get from simply walking at a comfortable pace for 45 minutes, about 350 less than Runkeeper gives me for the same class, and 260 less than MFP would give me if I entered it there.

Am I doing something wrong? I had logged class the class on RK, too (disconnected from MFP, so I won't be getting double credit for it), so I just overrode the automatic calorie burn, but given that everybody always claims that FitBit is better than MFP for tracking exercise, I'm wondering what the story is.

heybales

I'll mention that distance on spin bikes are worthless, actually any inside bike, as it relates to calories burned.

Because there is no air or rolling resistance, so speed is totally calculated out of the air value if based on the wheel turning. But calorie burn for biking is expecting those things, so you'd get badly inflated calorie burn anyway.

For spin bike HR-based is best bet, next Fitbit database with options of intensity.

So you created an Activity Record based on button push, and you are using a step-based model I'm guessing.
So you got estimate based on what Fitbit saw in steps and thinking you were walking or running based on impact seen.
How much impact you got during biking?

And steps are usually highly inaccurate for one thing on bikes, and the walking/running steps that are assumed in the formula for calorie burn have no relation at all to biking calorie burn.

Hence the reason you must manually log any non-step based workouts when using a step-based Fitbit.

My last outdoor bike ride stats:
Fitbit saw - 15890 steps - 8.34 miles - 2:41 - 1374 cal
Reality - didn't calculate based on cadence seen but could - 41.82 miles - 2:41 - 2269 cal

As you might guess, Fitbit's pace based on steps and impact would have been walking, slower than 4 mph, so not that intense. So for what it saw and can only assume was going on - probably a good estimate.
Totally incorrect for what happened though.

sarahmichelef

Forgot to mention that I'm using a Flex, so it's not even like I toggled an activity on the device - I logged it manually using the iPhone app after the fact.

I definitely think that you're on the right track with the steps versus actual effort problem, though. My Flex logged about 1000 steps during the class.

This does bring us back to the "fitbit (app) is not necessarily the best way to log non-step-based exercise" issue, though.