Fitbit added 908 cals this can't be right

Im getting back into MFP after an illness I've put on 2 stone so lots to loose
I went down the gym did a 30 min interval train for C25k which put my heart rate in cardio. then hit the weight machines which kept my heart rate in fat burn for about 1:30.

synced everything up and seen its awarded me 908 calories this can't be right, don't plan to eat them but nice to have a buffer I suppose 🤷

Replies

  • Lietchi
    Lietchi Posts: 6,841 Member
    Interval training and strength training are two types of exercise that are very susceptible to artificially high calorie burns if the estimates are based on heart rate. Without knowing anything about you (your height and weight) I agree that it sounds very high.
  • thanks for the reply I'm 5'8" and 15stone 6 so well into obese on BMI
  • Lietchi
    Lietchi Posts: 6,841 Member
    edited September 2022
    I like this calculator for running and walking:
    https://exrx.net/Calculators/WalkRunMETs
    If you ran the full 30 minutes (instead of intervals) at 8kph/5mph, that would have been 392 net calories. Walking at 6kph/3.2mph would be 147 net calories for 30 minutes.

    As for strength training, it's harder to estimate and depends on what you're doing precisely, but I'd guess perhaps 300 or so for an hour.
  • Retroguy2000
    Retroguy2000 Posts: 1,848 Member
    ^ The above estimate sounds reasonable, and since weights were for 1:30 you could estimate 450, gets you to potentially 850 total. That's the same estimate MFP gives for me for weights of that duration, and I'm just a fraction heavier.

    However...

    Those are gross calories, not net.

    You'd have burned (at 98kg) about 100 calories per hour sitting doing nothing for two hours, so the net add to MFP that you could eat back would be your exercise estimate minus 200. So a total of 650, or maybe a bit less if that C25K estimate is too generous. Which is still a very good workout and a great result.
  • AnnPT77
    AnnPT77 Posts: 34,234 Member
    What they said, plus: Is that 908 what you're seeing on the device as the calories just for exercise, or is it the total MFP calorie adjustment from synching your device to MFP?

    If it's the calorie adjustment from a synched device, it's not just reflecting exercise. It'd be including an estimate for any other movement (calorie burn) in your day that was in excess of MFP's estimate for you based on the activity level and what-not that you put in your MFP profile settings. Loosely speaking, if your MFP activity level setting is lower than your actual activity, you'll get a bigger calorie adjustment.

    Also, if it's from a synch, MFP and the tracker have theoretically reconciled any issues concerning gross vs. net estimates for the exercise per se. If it's you manually inputting the exercise calories from the workouts, using the individual workout calorie totals on your device, the gross vs. net distinction matters.