Calorie Confusion

geckstation
geckstation Posts: 8 Member
edited December 2024 in Getting Started
Hi All,
I have some confusion about the eating back all or half or none of the workout burned calories. I track my exercise with a Garmin Vivo. When I sync with the Garmin connect app I have the option to sync with MFP, which I do. MFP adjusts the amount of calories from the exercise that the Vivo reports, usually about 10-20% down. Say if I walk 4.5 miles and burn 755 calories according to Vivo, MFP will deduct somewhere between 75-150 carlories from the exercise. So do I now eat all the calories back because MFP has already made the adjustment? Do I still only eat half back of the new total? Do I ignore and don't eat any back?

Replies

  • sijomial
    sijomial Posts: 19,809 Member
    "Say if I walk 4.5 miles and burn 755 calories "
    That is incredibly high! How heavy are you? (You would have to be about 560lbs for that to be a net calorie burn for walking that distance.)
    Are you sure that number is just for the walk or is it more like a daily adjustment including exercise and activity?

    The aim when using MyFitnessPal as intended is to eat back ALL your ACTUAL exercise calories.
    Some people find some exercises in the database to be exceedingly high and recommend eating back a proportion. My personal view is that it makes more sense for people to make estimates that are at least reasonable and eat all of them back.

    Taking a random percentage off an estimate doesn't really make it more accurate - it just makes the number smaller.
  • geckstation
    geckstation Posts: 8 Member
    CW = 282, BMI = 35... Don't know I'm going by the Vivo app, for instance today I walked 4.97 miles in 97 minutes Average heart rate 100, Max heart rate 118 Garmin calculates that at 766 calories.

    I just plugged those into the Calorie Control Calculator and it returned 829 calories burned, Webmd has it at 786. Neither are using a heart monitor like the Vivo but are you sure that number is off?
  • MikePTY
    MikePTY Posts: 3,814 Member
    geckstation wrote: »
    CW = 282, BMI = 35... Don't know I'm going by the Vivo app, for instance today I walked 4.97 miles in 97 minutes Average heart rate 100, Max heart rate 118 Garmin calculates that at 766 calories.

    I just plugged those into the Calorie Control Calculator and it returned 829 calories burned, Webmd has it at 786. Neither are using a heart monitor like the Vivo but are you sure that number is off?

    If you are confident in them, especially with MFP adjusting it down a bit, I would eat all your calories back or close to it.
  • csplatt
    csplatt Posts: 1,231 Member
    edited April 2019
    100-118 seems really low if you are truly exercising. Mine gets up to 160-170. However that’s some good distance so who knows! I agree the calorie number seems too high for that kind of exertion (distance aside).
  • geckstation
    geckstation Posts: 8 Member
    I'm not confident in anything now.
  • kmfeig87
    kmfeig87 Posts: 1,990 Member
    I think it's pretty standard thought that a 180 pound person burns about 100 calories a mile. If you move faster you burn calories faster, in part because you finish the mile sooner! A lighter person burns fewer calories, a heavier person burns more. MFP may adjust the number down a little because instead of adding in the whole burn, maybe it adds the difference between what you say you burned and what it had already estimated you would burn during that time period if you hadn't exercised. So yes, eat back your exercise calories. (You can eat back 50-75% if you have set your MFP rate of loss to .5 or 1 pound a week and wanted to use those calories to lose 2 pounds a week. You probably don't want to aim to lose more than 2 pounds a week.)
  • deblcar
    deblcar Posts: 14 Member
    csplatt wrote: »
    100-118 seems really low if you are truly exercising. Mine gets up to 160-170. However that’s some good distance so who knows! I agree the calorie number seems too high for that kind of exertion (distance aside).
    The heart rate depends on age and physical condition. Basic formula is (220-age)x60-80%. So for myself at 60, 220-60=160, this should be my maximum heart rate. 60-80% for moderate to vigorous workouts would be approx 95-130. If someone is a beginner exerciser then they should work at 50-60% of max. I am an advanced exerciser, so I exercise at 80-90% of max.
    A basic way to guesstimate calorie burn for 1 mile is 100 calories for a 150 pound person. So, at 282 pounds the equation would look like this: 282-150=132, 132/282=47, 100+47=147 calories per mile, 147x4.97=730 calories burned. I hope this helps.
  • deblcar
    deblcar Posts: 14 Member
    edited April 2019
    Also, is that 4.97 your daily steps total or did you go for a 5 mile walk in addition to your normal routine? That makes a HUGE difference in whether to eat the calories back :smile: OOPS< just re-read that you did the walk in 97 minutes.
  • geckstation
    geckstation Posts: 8 Member
    It's a 5 mile walk, not daily steps.
  • sijomial
    sijomial Posts: 19,809 Member
    edited April 2019
    5 miles X 282 (weight in lbs) X 0.3 (efficiency ratio) = c. 423 net calories.
    That's using physics (mass moved over distance) to estimate energy expenditure rather than physiological data such as steps or HR.

    There's a good possibility that your Garmin is estimating gross calories (as many estimators do) but that doesn't account for the huge discrepancy.

    Personally I would eat back around 423 cals.
  • jlbtnc
    jlbtnc Posts: 725 Member
    Hi, i would eat a portion of calories back and not all. I am set at 1200 calories and with all my exercise it is sometimes well over 2,00 calories. I eat a portion of the calories back and eat up to 1500 calories. This may be wrong, but it works for me. I did see a video saying you should eat all calories back, but like others say the numbers can be somewhat exaggerated. Use your judgement and eat a certain amount if lose weight stick with that if not then adjust it some more. My amount of exercise changes daily but I always eat around 1500 calories. Sometimes late in the day and I stop eating at 6pm.
  • geckstation
    geckstation Posts: 8 Member
    I plugged the information into about 20 calorie counters and they all come back closer to the Garmin estimate than yours. Think I'll stick with the vivo measurement.
  • AnnPT77
    AnnPT77 Posts: 35,148 Member
    deblcar wrote: »
    csplatt wrote: »
    100-118 seems really low if you are truly exercising. Mine gets up to 160-170. However that’s some good distance so who knows! I agree the calorie number seems too high for that kind of exertion (distance aside).
    The heart rate depends on age and physical condition. Basic formula is (220-age)x60-80%. So for myself at 60, 220-60=160, this should be my maximum heart rate. 60-80% for moderate to vigorous workouts would be approx 95-130. If someone is a beginner exerciser then they should work at 50-60% of max. I am an advanced exerciser, so I exercise at 80-90% of max.
    A basic way to guesstimate calorie burn for 1 mile is 100 calories for a 150 pound person. So, at 282 pounds the equation would look like this: 282-150=132, 132/282=47, 100+47=147 calories per mile, 147x4.97=730 calories burned. I hope this helps.

    Heart rate doesn't determine or measure calorie burn. Calorie burn depends on the amount of work done, in pretty much the physics sense of "work". That's why sound calorie estimates for walking, based on distance and bodyweight, can be a reasonable approximation. In the case of walking, moving bodyweight through space is the work.

    A fit person will do that work at a lower heart rate (that's kind of the definition of fitness: adaptation to work), and an unfit one will do it at a higher heart rate. If both people are the same size, they'll burn roughly the same number of calories ( . . . and some heart rate monitors will estimate either or both of them inaccurately, because of the HR difference).

    HRmax also depends signficantly on genetics, and (in my understanding) declines more slowly with age in active people. The age-based calculations can be quite inaccurate for a surprising number of people. My HRmax by 220-age would be 157 (age 63). If I believed that, I'd severely undertrain. Actual (tested) HRmax is around 180. 157 is just nudging into anaerobic threshold; it's a HR I see and exceed fairly regularly during workouts. Without a tested HRmax, RPE (rate of perceived exertion) can be a better training guide, or at least a gut check on the age-based HRmax estimates.

    One needn't get their HR to any particular level to start burning calories. For the same person, a one-mile walk at HR 100 would burn about the same number of calories as a one-mile walk at HR 150. The walk at 150 (absent any pathological or confounding factors) would likely take a shorter time, though.

    OP, just stick with a consistent estimating method, carry on for 4-6 weeks, and adjust your intake based on weight loss results if needed. That works fine for most of us.
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