Do exercise calories vary with weight?

nxd10
nxd10 Posts: 4,570 Member
in Fitness and Exercise
Does MFP calculate different numbers of calories depending on your weight? In some ways that would make sense, but it surprises me.

My sister is on MFP, is taller than me, and weighs 100+ pounds more than me. She logged 8 minutes of walking for 55 calories. That seemed high. I tried logging it for me and it was only 32. Is it the weight? Or is she actually picking a different activity? It is labeled exactly the same.

I knew MFP calculates different calorie needs based on weight. But I didn't know they calculated different exercise calories. Maybe this is why people are always complaining about the 'huge number' of calories other people log for 'trivial' amounts of exercise? Heavy people do burn more and get more credit?

Replies

  • dfquigley
    dfquigley Posts: 186
    Yes, think about it this way.

    Exercising is doing "work". The amount of fuel to burn for a certain amount of work will depend on how hard you need to work.

    If your body weighs twice as much, you are going to need to work a lot harder than someone who is light and wafer this, to move in similar ways. Throw 30 pounds into a weight vest or backpack to see how much harder you have to work to run!

    It's like comparing the fuel efficiency of a little honda civic versus a big broken down old truck. It's heavier and less efficient, so it takes more fuel to get from point A to point B.
  • aswearingen22
    aswearingen22 Posts: 271 Member
    Yes I do believe it's the weight. It is harder work for a 300 pound guy to run a mile, than it is for a tiny 110 pound woman. My husband outweighs me by about 80 pounds and even when we use our HRM's during our runs, we'll run the same distance/time roughly and he'll burn about 125 calories per mile while I only burn about 80 per mile.
  • Azdak
    Azdak Posts: 8,281 Member
    Weight is one of the primary factors that determines calorie burn. The other is workload intensity.
  • neverstray
    neverstray Posts: 3,845 Member
    Yes.

    The good news is, as you lose, you should also be more fit, so the extra time and increased effort is no problem.
  • cwolfman13
    cwolfman13 Posts: 41,865 Member
    Weight is one of the primary factors that determines calorie burn. The other is workload intensity.

    ^^^^This^^^^.....also, when you're not very fit you don't have to do that much to get your heart rate up and get a burn. as you become more fit, it becomes harder to get and keep your heart rate up for that same burn which is why very fit individuals really have to work it hard to get anything out of it.
  • nxd10
    nxd10 Posts: 4,570 Member
    Huh. The program is better than I thought. This may also be why my exercise tracking program (RunKeeper) always gives me more calories for my walking than MFP does. Maybe I should trust MFP. Darn! Fewer exercise calories.
  • Azdak
    Azdak Posts: 8,281 Member
    Weight is one of the primary factors that determines calorie burn. The other is workload intensity.

    ^^^^This^^^^.....also, when you're not very fit you don't have to do that much to get your heart rate up and get a burn. as you become more fit, it becomes harder to get and keep your heart rate up for that same burn which is why very fit individuals really have to work it hard to get anything out of it.

    Yes and no. As fitness level improves, yes, one must work at a higher absolute intensity to get the same training benefits. However, since maximum fitness level has improved, that higher workload should feel roughly the same effort as before.

    E.g. A beginner is running at 5.0 mph with a heart rate of 150. After training, they may now have to run 6.0 mph to reach the same heart rate of 150. So technically, yes, they are working "harder". However, at the beginning, that 5.0 mph may have been 75% of their maximum. Now, since max fitness has improved, although the actual speed is faster, it still represents 75% of maximum.
  • BlackKat75
    BlackKat75 Posts: 210 Member
    Huh. The program is better than I thought. This may also be why my exercise tracking program (RunKeeper) always gives me more calories for my walking than MFP does. Maybe I should trust MFP. Darn! Fewer exercise calories.

    Weird - RunKeeper and MFP are pretty much exactly the same for me when I run (roughly 6 mph), but MFP gives me *way* more calories for walking than RunKeeper does.
  • Azdak
    Azdak Posts: 8,281 Member
    Huh. The program is better than I thought. This may also be why my exercise tracking program (RunKeeper) always gives me more calories for my walking than MFP does. Maybe I should trust MFP. Darn! Fewer exercise calories.

    The two should be using similar equations for estimating calories for walking. It depends on how precisely you enter the data. I don't use MFP to track calories, so I forget how they do walking.

    If you are entering the exact speed (e.g. 3.5 mph) and elevation (probably 0 if you are walking outside), then the calorie burns should be similar.

    If one has you putting in "walking, brisk pace" or only allows larger increments (e.g. choosing between 3.0 and 3.5 w/nothing in between) then that might be a discrepancy.

    If you are using the GPS on Run Tracker, then it is calculating all the fluctuations in walking speed that occur and there are going to be discrepancies due to how well it is picking up the GPS signal.
  • contraryquite
    contraryquite Posts: 22
    Yes, think about it this way.

    Exercising is doing "work". The amount of fuel to burn for a certain amount of work will depend on how hard you need to work.

    If your body weighs twice as much, you are going to need to work a lot harder than someone who is light and wafer this, to move in similar ways. Throw 30 pounds into a weight vest or backpack to see how much harder you have to work to run!

    It's like comparing the fuel efficiency of a little honda civic versus a big broken down old truck. It's heavier and less efficient, so it takes more fuel to get from point A to point B.

    This is right ^.


    However, I don't know if MFP calculates individual calorie expenditure based on weight for your logged exercise. I believe that if two users of a different weight were to log the exact same exercise/duration from one of the pre-populated choices that the recorded 'burn' would be the same. I'd be interested to know the answer!

    As a result, when I log my cardio I use the figures from gym equipment where weight is factored into time and effort; as oppose a calculation from MFP

    Being a scientist; I'm sceptical about some of the calorie calculations so where I can't ue my own based on gym equipment or my HRM, I always estimate conservatively
  • debi_f
    debi_f Posts: 330 Member
    Yes, MFP takes weight into account. I guess it assumes that the less you weigh, the less it takes to accomplish a "task."

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