Calories burned differs if I "Select an Exercise" instead of letting it auto-detect a workout

[Weinbagel]

There are two ways to record a workout:

1. Tell Fitbit you are going to start working out by choosing an exercise on the device.

2. Let Fitbit auto-detect a workout after 15 minutes of activity.

I have done the same exercise routine for 70 minutes, and the calories burned varies greatly between the two methods. When I tell Fitbit I am going to workout before I start, it will tell me I burn over 600 calories. If I let it auto-detect my workout, it will tell me I burn under 200 calories. My daily calories also vary greatly.

I feel like it should be the same regardless of whether or not Fitbit knows I'm exercising, since it is supposed to be based on heart rate. I am NOT manually adding a workout after I finish.

I would like to get the most accurate reading, and I'm not sure which is the better route to go?

[JohnnyRow]

When you use auto-detect, check what it has for the length of the workout.  Sometimes that does not detect the full length of the workout, which would fit with it being fewer calories in less duration.  Perhaps short rest breaks were interpreted breaking it into separate workouts, some not meeting the required time.

That's one reason I prefer the Exercise App, telling it when I start and stop (your method 1), to be sure the full time of the workout is credited.

[Weinbagel]

Good suggestion, thank you! But it still doesn't make sense regarding my total calories burned for the day! 😞

[JohnnyRow]

Iif your workout was just recorded for a shorter duration, the calories would still be getting counted in daily total, just not as part of an "exercise".

Check the fitbit.com dashboard.  On the wide graph with 2 drop-down menus at right, select 'calories' and 'daily' to look at the calories burned throughout the day.  Check if you are still credited higher calories during the time you say you were exercising but didn't get included as an "exercise".

[Weinbagel]

Thanks! I checked the dashboard, and on the day when I told it I was exercising, it claimed I was burning over 100 calories (sometimes up to 140 calories!) in each 15 minute increment. When I let it auto detect, it claimed I was burning 60 - 75 calories in each 15 minute increment. So, something definitely isn't adding up.

Also, when I told it I was working out yesterday, I started by only walking (for about 8 minutes), it said my heart rate was over 175bpm. I'm 33, 5'6, and 145lbs, so that is not accurate. This makes me think maybe it is overcompensating on my heart rate, which makes it think I'm burning more calories. I would love to find a solution to this!

[rew11510]

Mine definitely overcompensates on HR. I'll do a brisk walk on the treadmill and it will say my heartrate is 203.. lol I seriously doubt that. 

[JohnnyRow]

@Weinbagel   The higher heart rate definitely explains the difference in calories.

But my guess would be that it was not related to how the exercise was recorded, rather just that sometimes optical heart rate monitors get it wrong.  However, it would be interesting to see if you continue to see that difference in how you record the workout.

[Weinbagel · Accepted solution]

True, but, as far as I can tell, it only goes wonky when it knows I'm working out. So I guess I will avoid the "record workout" feature from now on.