Calories burned running: is speed a factor at all?

Options
245678

Replies

  • Smuterella
    Smuterella Posts: 1,623 Member
    Options
    Tuesday I ran 7K in 48 minutes and burned 350 calories

    Thursday I ran 4K between sprinting and walking in 30 minutes and burned 315 calories


    So speed, at least in the case of intervals, increases burn.
  • mikeyrp
    mikeyrp Posts: 1,616 Member
    Options
    Tuesday I ran 7K in 48 minutes and burned 350 calories

    Thursday I ran 4K between sprinting and walking in 30 minutes and burned 315 calories


    So speed, at least in the case of intervals, increases burn.

    Can I ask how you measured this? HRM?

    Makes complete sense to me based on my feeling after interval training!
  • Shadowsan
    Shadowsan Posts: 365 Member
    Options
    Tuesday I ran 7K in 48 minutes and burned 350 calories

    Thursday I ran 4K between sprinting and walking in 30 minutes and burned 315 calories


    So speed, at least in the case of intervals, increases burn.

    This ties in to my explanation of fighting against inertia burning more calories than maintaining momentum.
  • rkr22401
    rkr22401 Posts: 216 Member
    Options
    Efficiency is work output divided by work input. If you get out all you put in you would be 100% efficient. This is never the case in the real world due to losses in efficiency from friction, etc.

    Think of it this way. Running 5 miles on a paved surface is easier than slogging 5 miles through knee-deep mud. Same distance but you'd have to expend a great deal more energy to overcome the "friction" losses associated with the running surface.
  • Smuterella
    Smuterella Posts: 1,623 Member
    Options
    Tuesday I ran 7K in 48 minutes and burned 350 calories

    Thursday I ran 4K between sprinting and walking in 30 minutes and burned 315 calories


    So speed, at least in the case of intervals, increases burn.

    Can I ask how you measured this? HRM?

    Makes complete sense to me based on my feeling after interval training!

    Yep - Polar FT4 :-)
  • mirandamayhem
    mirandamayhem Posts: 772
    Options
    Tuesday I ran 7K in 48 minutes and burned 350 calories

    Thursday I ran 4K between sprinting and walking in 30 minutes and burned 315 calories


    So speed, at least in the case of intervals, increases burn.

    Can I ask how you measured this? HRM?

    Makes complete sense to me based on my feeling after interval training!

    Interval training is meant to be more intense isn't it? Because you're raising and dropping your heart rate, so it's a bit start stop, rather than continuing with momentum?
  • Aperture_Science
    Aperture_Science Posts: 840 Member
    Options
    OK - I'm going to rephrase the question because I think some people are missing my point- if my target was to burn, say, 500 calories running - would I always go the same distance irrespective of the speed I was running at?

    roughly... yes

    you have performed the same amount of work (you have hauled yourself over a distance).

    There are small factors (as other point out) of wind resistance and inertia but they are tiny compared to the total energy expended.

    P.S. the walking is the same as running argument is not so straight forward. When you run you lift both feet off the ground, this has an energy requirement that is not present when you walk. So running will always expend more energy than an equivalent distance walk (although the differences will depend upon your running form; less for a shuffler, more for a sprinter).
  • rkr22401
    rkr22401 Posts: 216 Member
    Options
    Tuesday I ran 7K in 48 minutes and burned 350 calories

    Thursday I ran 4K between sprinting and walking in 30 minutes and burned 315 calories


    So speed, at least in the case of intervals, increases burn.

    Work is force times distance. Force is mass times acceleration. Ergo work is mass times acceleration times distance. Intervals require more acceleration than steady state running...more energy/calories if your intervals are at sufficient frequency.

    Acceleration is not the same as speed. It is the rate of change in momentum.
  • Martucha123
    Martucha123 Posts: 1,093 Member
    Options
    OK - I'm going to rephrase the question because I think some people are missing my point- if my target was to burn, say, 500 calories running - would I always go the same distance irrespective of the speed I was running at?

    yes I belive you burn pretty much same amount of kcals running 3 miles, it does not matter if you complete the distance in 20 or 30 minutes
  • retrobaby
    retrobaby Posts: 613 Member
    Options
    Oh...you ALL made me smile today with all this math talk.
  • Arrabindi
    Arrabindi Posts: 169 Member
    Options
    Calories/mile is (almost) constant for a given person - slight variations are due to air resistance, movement of other body parts than the legs (running style) etc., but as a rule of thumb, the calories burned per mile is constant. As someone else pointed out, it's just basic physics.

    However, there are a lot of other effects that differ with speed/effort. Really getting your heart pumping does so many great things to your body other than just the calorie burn. Several studies conclude that high intensity training sort of relocates the fat, so you will have less fat around the internal organs and on your belly, which is great for your health. So basically, if one simply wants to lose weight, doesn't like to get sweaty and has plenty of time it's great to take a long walk. But the health benefits from interval training or other high intensity cardio are far superior to walking or jogging.
  • Stoicus
    Stoicus Posts: 34 Member
    Options
    When I run 5k at an easy pace I burn around 250 calories, when I run it at race pace I burn around 490. I use a HRM. I've found MFP estimates to be completely inaccurate as far as calories burned are concerned.
  • mikeyrp
    mikeyrp Posts: 1,616 Member
    Options
    OK - I just did an experiment with MFP exercise calorie calculator - I took the pace and entered the same value for the minutes of exercise (eg 6 minute mile pace, 6 minutes) - which means that the output is the number of calories per mile. As my weight is a fixed quantity and MFP doesn't know my fitness level we can assume that there are no other factors changing.These are the results.

    pace / cals
    6 / 122
    7 / 124
    8 / 127
    9 / 126
    10 / 127
    12 / 122

    As you can see, there is no linear correlation between pace and cals per mile shown here - meaning either MFP has incorrect values (possible) or that there really is no correlation and that the body doesn't have a peak efficiency in terms of running speed.

    Note that I would define efficiency here in terms of calories burnt - obviously muscle fatigue sets in over a shorter distance at higher speeds.

    This means that the calculator is wrong really.

    Although how wrong is debatable. Obviously to increase speed, you may be able to do that simply by increasing your stride length which would result in nearly the same amount of muscle contractions as the slower speed.

    Which ties in to what I originally said - as your speed increases, the difference in expenditure begins to result in an inverse exponential curve - diminishing returns.


    Can I ask what you are basing this information on? I'm not saying its wrong - I'm just trying to determine if this is something you are deriving for yourself of based on a study.



    My instinct is that most people have a 'natural pace' which is going to be very efficient - running below this pace will burn marginally less efficient but will produce a pretty similar cals burned / mile. As you start to increase from this pace I would expect efficiency to decrease as technique will start to suffer.

    Also - as you pointed out there are two ways to increase speed - the first is to increase cadence (number of foot falls per minute) - the second is to increase stride length. Interestingly - my learning is that during a long distance run you should maintain cadence and alter stride length to manage your effort levels - however to improve your net running speed you need to work on increasing your cadence. I have no idea how this impacts efficiency either.
  • Shadowsan
    Shadowsan Posts: 365 Member
    Options
    Calories/mile is (almost) constant for a given person - slight variations are due to air resistance, movement of other body parts than the legs (running style) etc., but as a rule of thumb, the calories burned per mile is constant. As someone else pointed out, it's just basic physics.

    However, there are a lot of other effects that differ with speed/effort. Really getting your heart pumping does so many great things to your body other than just the calorie burn. Several studies conclude that high intensity training sort of relocates the fat, so you will have less fat around the internal organs and on your belly, which is great for your health. So basically, if one simply wants to lose weight, doesn't like to get sweaty and has plenty of time it's great to take a long walk. But the health benefits from interval training or other high intensity cardio are far superior to walking or jogging.

    Yup - the secondary effects from increasing intensity are just as important if not more so than plainly calories burnt. Increasing your bodys ability to carry oxygen and expend more energy via aerobic respiration is extremely important. Because by training this, you also increase your bodys ability to expend more calories via aerobic respiration at lower intensity - just like doing weight training and increasing your muscle mass increases your resting metabolic rate.
  • rkr22401
    rkr22401 Posts: 216 Member
    Options
    OK - I just did an experiment with MFP exercise calorie calculator - I took the pace and entered the same value for the minutes of exercise (eg 6 minute mile pace, 6 minutes) - which means that the output is the number of calories per mile. As my weight is a fixed quantity and MFP doesn't know my fitness level we can assume that there are no other factors changing.These are the results.

    pace / cals
    6 / 122
    7 / 124
    8 / 127
    9 / 126
    10 / 127
    12 / 122

    As you can see, there is no linear correlation between pace and cals per mile shown here - meaning either MFP has incorrect values (possible) or that there really is no correlation and that the body doesn't have a peak efficiency in terms of running speed.

    Note that I would define efficiency here in terms of calories burnt - obviously muscle fatigue sets in over a shorter distance at higher speeds.

    This means that the calculator is wrong really.

    Although how wrong is debatable. Obviously to increase speed, you may be able to do that simply by increasing your stride length which would result in nearly the same amount of muscle contractions as the slower speed.

    Which ties in to what I originally said - as your speed increases, the difference in expenditure begins to result in an inverse exponential curve - diminishing returns.


    Can I ask what you are basing this information on? I'm not saying its wrong - I'm just trying to determine if this is something you are deriving for yourself of based on a study.



    My instinct is that most people have a 'natural pace' which is going to be very efficient - running below this pace will burn marginally less efficient but will produce a pretty similar cals burned / mile. As you start to increase from this pace I would expect efficiency to decrease as technique will start to suffer.

    Also - as you pointed out there are two ways to increase speed - the first is to increase cadence (number of foot falls per minute) - the second is to increase stride length. Interestingly - my learning is that during a long distance run you should maintain cadence and alter stride length to manage your effort levels - however to improve your net running speed you need to work on increasing your cadence. I have no idea how this impacts efficiency either.

    As your efficiency improves you will expend less energy for the same output. A more efficient runner will burn fewer calories over a given distance than a less efficient runner (all other factors being consistent).
  • tadpole242
    tadpole242 Posts: 507 Member
    Options
    http://www.runnersworld.com/article/0,7120,s6-242-304-311-8402-0,00.html

    In "Energy Expenditure of Walking and Running," published last December in Medicine & Science in Sports & Exercise, a group of Syracuse University researchers measured the actual calorie burn of 12 men and 12 women while running and walking 1,600 meters (roughly a mile) on a treadmill. Result: The men burned an average of 124 calories while running, and just 88 while walking; the women burned 105 and 74. (The men burned more than the women because they weighed more.)

    http://www.ncbi.nlm.nih.gov/pubmed/15570150
    CONCLUSION:
    Running has a greater energy cost than walking on both the track and treadmill. For running, the Leger equation and ACSM prediction model appear to be the most suitable for the prediction of running energy expenditure. The ACSM and Pandolf prediction equation also closely predict walking energy expenditure, whereas the McArdle's table or the equations by Epstein and van der Walt were not as strong predictors of energy expenditure.

    http://w4.ub.uni-konstanz.de/cpa/article/viewFile/450/390
    The study presented here shows that running has a higher energetic cost compared to
    walking the same distance, what might be associated to a higher vertical oscillation on
    gravity center during running. This knowledge may be useful on exercise prescription in order
    to achieve negative caloric balance, also considering factors as time for exercise practice
    and orthopedic limitations.
  • mikeyrp
    mikeyrp Posts: 1,616 Member
    Options
    When I run 5k at an easy pace I burn around 250 calories, when I run it at race pace I burn around 490. I use a HRM. I've found MFP estimates to be completely inaccurate as far as calories burned are concerned.

    Hmm... the HRM on my Garmin 305 doesn't impact the calorie calculations (its designed to be used in HR training) - I really don't want to go out wearing two watches :) Garmin gives similar cal estimates to MFP by the way.


    By the way - I completely agree about mixing up the training intensity in terms of overall fitness. Burning Cals -> loosing weight is just one factor in getting fit.
  • Shadowsan
    Shadowsan Posts: 365 Member
    Options
    OK - I just did an experiment with MFP exercise calorie calculator - I took the pace and entered the same value for the minutes of exercise (eg 6 minute mile pace, 6 minutes) - which means that the output is the number of calories per mile. As my weight is a fixed quantity and MFP doesn't know my fitness level we can assume that there are no other factors changing.These are the results.

    pace / cals
    6 / 122
    7 / 124
    8 / 127
    9 / 126
    10 / 127
    12 / 122

    As you can see, there is no linear correlation between pace and cals per mile shown here - meaning either MFP has incorrect values (possible) or that there really is no correlation and that the body doesn't have a peak efficiency in terms of running speed.

    Note that I would define efficiency here in terms of calories burnt - obviously muscle fatigue sets in over a shorter distance at higher speeds.

    This means that the calculator is wrong really.

    Although how wrong is debatable. Obviously to increase speed, you may be able to do that simply by increasing your stride length which would result in nearly the same amount of muscle contractions as the slower speed.

    Which ties in to what I originally said - as your speed increases, the difference in expenditure begins to result in an inverse exponential curve - diminishing returns.


    Can I ask what you are basing this information on? I'm not saying its wrong - I'm just trying to determine if this is something you are deriving for yourself of based on a study.



    My instinct is that most people have a 'natural pace' which is going to be very efficient - running below this pace will burn marginally less efficient but will produce a pretty similar cals burned / mile. As you start to increase from this pace I would expect efficiency to decrease as technique will start to suffer.

    Also - as you pointed out there are two ways to increase speed - the first is to increase cadence (number of foot falls per minute) - the second is to increase stride length. Interestingly - my learning is that during a long distance run you should maintain cadence and alter stride length to manage your effort levels - however to improve your net running speed you need to work on increasing your cadence. I have no idea how this impacts efficiency either.

    Basing my opinions on 4 years of sports science research (i.e. reading a LOT of books and plenty of practical tests) at university.

    There are admittedly lots of factors in this, like you've said. Making your body do the most inefficient things is the best way to increase calorie expenditure. And the body itself does have a natural speed (which varies per person) at which they are at their most efficient.

    As for interval training and its effects - interval training generally if you're sprinting as fast as you can for 30 seconds and then go to a steady state running/walking for 2/3 mins to recover and then go again... Not only trains your aerobic system (which uses aerobic respiration, which is extremely efficient per gram of glucose), but also trains your anaerobic/lactic acid system (which is inefficient by comparison - anaerobic respiration typically can produce about 2ATP per molecule of glucose - aerobic respiration for the same molecule of glucose can provide about 30ATP. 15 times more efficient)

    So if you wanted to really burn lots of calories, you'd do plenty of high intensity intervals, with active recovery between for your aerobic system to address the balance before going again.
  • rkr22401
    rkr22401 Posts: 216 Member
    Options
    Intuitively, it seems walking would be a more energy efficient means to travel a given distance than running (not a more time efficient means). With running your are expending additional energy lifting your body weight off the ground. When walking, one foot remains in contact with the ground at all times. This explains the higher calorie burn associated with running as compared to walking.
  • Shadowsan
    Shadowsan Posts: 365 Member
    Options
    Intuitively, it seems walking would be a more energy efficient means to travel a given distance than running (not a more time efficient means). With running your are expending additional energy lifting your body weight off the ground. When walking, one foot remains in contact with the ground at all times. This explains the higher calorie burn associated with running as compared to walking.

    Exactly. You're fighting against a force (in this case, gravity).

    It's also why for instance, if you stood still doing squats with bodyweight for the same amount of time you tried running for, you would also burn more calories.

Categories