Calories burned estimate changed significantly after syncing

[caeliter]

I went for a long ride today. (100km) When I get back, my surge says "calories burned" are 5800 or so.

After I sync the watch to my phone, it changes and is now showing 4183 calories burned.

So I just did a quick google:

http://www.fitnessforweightloss.com/how-many-calories-do-i-burn-biking/

Using the values from that page (I weight 215, but my average speed was just under 10mph so using the 200lb values I should be between 3230 and 4845 for just my 510 minute ride.) Now those values don't account for wind or hills, so I'm just feeling like 4183 for the whole day is probably not right.

I'm not sure if this is related or not, but due to the low battery life in the surge when using GPS, I had to switch devices during my ride. (It didn't die completely though, so it was still tracking my HR) After both rides were uploaded to Strava, I found a tool online for merging activities so I downloaded them, merged them then manually re-uploaded the new merged version to strava then deleted the old rides. This uploaded a duplicate of my original ride (though 22 miles further) to fitbit so I deleted the duplicate off the fitbit app as well. My Surge was showing over 5000 before the duplicate ride was created. I'm wondering if deleting the duplicate deducted those calories from the total.

Anyway, this is especially frustrating because I was just about to go out and grab some dinner and but I don't even have a ballpark value for how much I still need to eat today.

[MarreFitbit · Accepted solution]

It's nice to see you around the Community @caeliter ! Typically, your steps will be recalculated if you manually log an activity as the manually logged activity takes precedence over the data tracked while wearing your tracker at that point in time. For example, if I am wearing my Surge and walking and I reach 500, then I go to the computer and manually log an activity that starts and ends at that point in time for say 1 hour, Fitbit will calculate how many calories you burned and it may bring my calories count to something below 500. To clarify, activities should only be manually logged when you forget to wear your tracker. 

Your Fitbit activities will now appear on Strava, and your runs and rides tracked by Strava will contribute to your Fitbit all-day stats. If you're interested in exporting your GPS data from your Fitbit Surge to Strava, see Can I export my fitness data to my computer?

Keep in mind that the following types of activities won't sync to Strava:

• Non-GPS activities 
• Previously completed activities
• Duplicate activities—that is, if you already recorded an activity with Strava, a Fitbit activity that occurs at the same time won't sync.

Note that after linking your accounts you may see some differences in the way data is calculated for your exercises on each site. For more information, refer to Strava'sCalorie Calculation article.

Hope this helps!