I keep reading this here, but it doesn't make sense to me
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hbrittingham
Posts: 2,518 Member
When people are talking about calories burned when running, there are several people who say that a HRM isn't necessary, that all you need to do is take your weight x .66 x distance in miles and you will get an accurate calorie burn.
I am admittedly not the brightest bulb in the box when it comes to math and science, so that may be why it doesn't make sense to me.
Say that I weigh 170 lbs and I regularly run 2-3 miles at a time. I'm 5'5" tall and in decent shape, but running 5 miles would be a tough challenge to me.
Say a guy weighs 170 lbs and he regularly runs marathons. He's 5'11" and in great physical shape.
Say a woman weighs 170 lbs and she struggles to run 1 mile. She's 5'0".
Now all three of us run 3 miles. Do we all honestly burn the exact same number of calories? I am pretty sure the guy wouldn't even break a sweat, I'd be sweating pretty decently and the other woman would likely be exhausted. I am also pretty sure that all of our heart rates would vary hugely.
Can anyone explain this to me, in simple terms for my simple mind?
I am admittedly not the brightest bulb in the box when it comes to math and science, so that may be why it doesn't make sense to me.
Say that I weigh 170 lbs and I regularly run 2-3 miles at a time. I'm 5'5" tall and in decent shape, but running 5 miles would be a tough challenge to me.
Say a guy weighs 170 lbs and he regularly runs marathons. He's 5'11" and in great physical shape.
Say a woman weighs 170 lbs and she struggles to run 1 mile. She's 5'0".
Now all three of us run 3 miles. Do we all honestly burn the exact same number of calories? I am pretty sure the guy wouldn't even break a sweat, I'd be sweating pretty decently and the other woman would likely be exhausted. I am also pretty sure that all of our heart rates would vary hugely.
Can anyone explain this to me, in simple terms for my simple mind?
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Replies
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Because it's still just physics. It takes X work to move Y mass Z distance.
Take a car for example. If it takes 75 hp to go 60 MPH, it doesn't matter if it comes from a I4 or a V12, it's the same amount of work (hp).0 -
Because many people here are of the opinion that the average poster here should only focus on the absolute simplest of tools and calculations. I think that there is a group that should adhere to this and a group that shouldn't, and if you're asking yourself that kind of question then you should be using something a bit more precise. You running a mile at 7mph and a seasoned athlete running a mile at 7mph are going to have very different results.
This whole process can get extremely, and often overly, complicated. Think of those rock-simple basics as 50%-60% of the real information and the more complex tools as a search for the remaining % with ever-diminishing returns. Because some of the toys that work to close that gap are so cool and interesting though, people tend to chase that and lose sight of the bigger picture. Like people who will have a heated debate between the merits of 2 variations of the squat, you can focus too much on the minutia.
I wouldn't consider a heart rate monitor for myself because for the exercise that I do and the shape that I am in it would be wildly inaccurate. (Strength training, HIIT, Brazilian Jiu Jitsu) For a low to middle shape endurance runner or biker, that tool is going to be quite accurate, all things considered.
Even with those tools, I think it all really comes back to the basics.
Are you getting faster, stronger, and have more energy without causing injury? The exercise is working.
- Is it getting easier? Then work harder
- Not getting stronger? Then work harder and educate yourself to see if you're doing something wrong
Are you eating when you're not hungry? Stop it and listen to your body
Are you not eating when you/re hungry? Stop it and listen to your body
Are you gauging your self-worth by the numbers on the scale? Stop it and learn to like yourself no matter what
- Part of liking yourself is doing what's best for you, like exercise and a good diet.0 -
I honestly disagree. I have a HRM. Even if I go to the Polar training website and type in my sex/height/weight/etc--I enter my exercise time and the amount it calculates is almost double the calories my HRM confirms. Even if I enter my "average" heart rate (which my polar watch gives me) it still calculates WAY over the calories my watch gives me. Your heartrate is going to be unique to you. Nobody works out the same during a run.0
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stop over thinking it and go for a damn run.
seriously- it's not THAT critical.
I haven't used a HRM in- well ever. I've never owned one. I've survived almost 20 years of working out and I look great.0 -
What is more heavy? 5 pounds of popcorn or 5 pounds of stones?
Lets say you take two 5 pound bags. One is bag of of popcorn and other is bag of stones. Popcorn bag is bigger but stones bag is smaller even if they both weight the same. Which do you think you will need more strength to lift? They both weight the same...
In this case your muscle strength = energy necessary to move the object. Even if they both are different size the weight is the same, therefore you will need same amount of energy to move them.
In runner example energy necessary to move the object (person) = calories (cos calories are basically energy). Even if they are different size it doesn't matter because they both weight the same.
Now the thing is, just because it is harder for you to run than other guy doesn't mean he burns less calories. Energy necessary to move the mass is still the same, basics rules of physics apply. It's just that he doesn't feel it anymore cos he is used to it.0 -
Thanks for all the thoughts and opinions on this!
scorpio516, that's the simple explanation I needed. But it just opens up another question in my mind. If you drive 60 mph in a 4 cylinder, a 6 cylinder and an 8 cylinder, isn't the fuel used more based on the size of the engine?
Alehmer, thanks. You are right, it can be overly complicated! I am not the most logical person in the world, but if it doesn't make sense, I try to figure out how to make it make sense. lol0 -
I am strongly looking forward to being strongly entrenched with my maintenence and not worrying about how many calories I'm burning while I am running. I haven't done the math and trending but my calorie burn from running (per distance/time) seems to have gotten lower quicker than my weightloss and I believe it is because I have become a stronger / more efficient runner and running isn't quite the effort it used to be and I don't believe that the ease has come completely from being lighter and having to move less of a body to move my body.
But that's all just empirical evidence and not backed by even simple statistical analysis.0 -
I think they're saying you will get a passable estimate. A HRM also gives a passable estimate. If you are an elite runner or an obese midget, you might be at some end of 'normal' but for most of us, the estimates are good enough. We're not going to get any actual calorie burns, so you use what you have.that all you need to do is take your weight x .66 x distance in miles and you will get an accurate calorie burn.
I don't think amount of sweat has anything to do with calorie burn. Some people just sweat more.0 -
Thanks for all the thoughts and opinions on this!
scorpio516, that's the simple explanation I needed. But it just opens up another question in my mind. If you drive 60 mph in a 4 cylinder, a 6 cylinder and an 8 cylinder, isn't the fuel used more based on the size of the engine?
Alehmer, thanks. You are right, it can be overly complicated! I am not the most logical person in the world, but if it doesn't make sense, I try to figure out how to make it make sense. lol
Exactly!!! You can't compare a 4cy to an 8 cy.0 -
It's not true that two runners at the same weight but different fitness will burn the same calories. Imagine two identical cars, one with slightly deflated tyres. One will burn more fuel because it's less efficient.0
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What is more heavy? 5 pounds of popcorn or 5 pounds of stones?
Lets say you take two 5 pound bags. One is bag of of popcorn and other is bag of stones. Popcorn bag is bigger but stones bag is smaller even if they both weight the same. Which do you think you will need more strength to lift? They both weight the same...
In this case your muscle strength = energy necessary to move the object. Even if they both are different size the weight is the same, therefore you will need same amount of energy to move them.
In runner example energy necessary to move the object (person) = calories (cos calories are basically energy). Even if they are different size it doesn't matter because they both weight the same.
Now the thing is, just because it is harder for you to run than other guy doesn't mean he burns less calories. Energy necessary to move the mass is still the same, basics rules of physics apply. It's just that he doesn't feel it anymore cos he is used to it.
This is incorrect. You are assuming the exact same machinery behind the work when that's not the case. Looking at the support system alone, a seasoned athlete has a much more efficient energy delivery to those muscles for the same muscular output. Greater capillary density in the muscle tissue, expanded lung capacity and oxygen absorption, higher red blood cell count, greater standing glycogen stores in the muscles, etc etc etc. An athlete of the same weight on the same run will burn fewer calories than a beginner on the run, and then most importantly will burn far fewer after the run in recovery because of that same support system.
Why do you think one person is doubled over, gasping for air and red-faced after a mile run while another person barely breaks a sweat? The out of shape person has a significant bottleneck on their ability to deliver oxygen and glycogen to those muscles and has to work much harder to fuel the same activity. They are gasping because they can't get enough oxygen out of the same air, shaking because those muscles have exhausted their 'ready' energy stores and have fallen back on much less efficient processes, and their hearts are pounding because the heart is struggling to delivery the necessary resources through a cruddy delivery system with far more beats to get the same job done.0 -
What is more heavy? 5 pounds of popcorn or 5 pounds of stones?
Lets say you take two 5 pound bags. One is bag of of popcorn and other is bag of stones. Popcorn bag is bigger but stones bag is smaller even if they both weight the same. Which do you think you will need more strength to lift? They both weight the same...
In this case your muscle strength = energy necessary to move the object. Even if they both are different size the weight is the same, therefore you will need same amount of energy to move them.
In runner example energy necessary to move the object (person) = calories (cos calories are basically energy). Even if they are different size it doesn't matter because they both weight the same.
Now the thing is, just because it is harder for you to run than other guy doesn't mean he burns less calories. Energy necessary to move the mass is still the same, basics rules of physics apply. It's just that he doesn't feel it anymore cos he is used to it.
This is incorrect. You are assuming the exact same machinery behind the work when that's not the case. Looking at the support system alone, a seasoned athlete has a much more efficient energy delivery to those muscles for the same muscular output. Greater capillary density in the muscle tissue, expanded lung capacity and oxygen absorption, higher red blood cell count, greater standing glycogen stores in the muscles, etc etc etc. An athlete of the same weight on the same run will burn fewer calories than a beginner on the run, and then most importantly will burn far fewer after the run in recovery because of that same support system.
Why do you think one person is doubled over, gasping for air and red-faced after a mile run while another person barely breaks a sweat? The out of shape person has a significant bottleneck on their ability to deliver oxygen and glycogen to those muscles and has to work much harder to fuel the same activity. They are gasping because they can't get enough oxygen out of the same air, shaking because those muscles have exhausted their 'ready' energy stores and have fallen back on much less efficient processes, and their hearts are pounding because the heart is struggling to delivery the necessary resources through a cruddy delivery system with far more beats to get the same job done.
Thank you! That's what I was trying to ask and describe in my OP.0 -
There is a lot of good information on this topic in this thread: http://www.myfitnesspal.com/topics/show/97228-fit-vs-unfit-calories-burned-doing-identical-exercise
The summary seems to be that if you take two runners who are the same age, height and weight and only differ in fitness level then, yes, the energy they use to run the same distance at the same speed will be roughly the same. The thread doesn't mention it but I'd imagine this has been confirmed by getting people to run on a treadmill and measuring how much CO2 they breathe out and thus how many calories they are burning.
The thread also says that HRMs can be misleading when you use them to calculate calories burned. To work out calories HRMs take your age, weight etc. and use a statistical model to work out the maximum rate at which you can use oxygen or VO2 max. As you get fitter your VO2 max will improve and move further away from this statistical average. This will lead the HRM to underestimate the calories you are burning unless you measure your own VO2 max and enter it.0 -
First and foremost a calorie is a unit of energy. It is a constant, to get technical it is the approximate amount of energy needed to raise the temperature of one gram of water by one degree Celsius. In order to determine a unit of energy you need three things; mass (weight of the person), distance, and time. V02 max also factors into this when talking about humans.
Any equation for calories that doesn't factor in at least mass, distance, and time is incorrect. Since the equation in the original post has a constant for mass I consider it an incorrect equation.0 -
Thanks for all the thoughts and opinions on this!
scorpio516, that's the simple explanation I needed. But it just opens up another question in my mind. If you drive 60 mph in a 4 cylinder, a 6 cylinder and an 8 cylinder, isn't the fuel used more based on the size of the engine?
Alehmer, thanks. You are right, it can be overly complicated! I am not the most logical person in the world, but if it doesn't make sense, I try to figure out how to make it make sense. lol
Not necessarily. Fuel use is based on load on an engine, which is dictated by gearing and aerodynamics.
My 4 cylinder Volvo gets 18-20 MPG. A Corvette gets about 30 MPG at highway speeds because it's geared to go 175 MPH, so 70 mph is barely working the engine at all. Not totally comparable with a human running.
I know this goes against your whole plain english point, but this is where the numbers come from:
http://www.ncbi.nlm.nih.gov/pubmed/15570150
And here's another article that refutes the counterpoint:
http://jap.physiology.org/content/18/2/367
The research states that elite runners only burn 5-7% fewer calories than an average runner/schlub off the street. Economy of running only counts for very, very little changes.0 -
How do you figure it has a constant mass? It has body weight as one of the variables. It doesn't have a time variable but I imagine they're using some 'normal human running speed' as that.Since the equation in the original post has a constant for mass I consider it an incorrect equation.
Even if you run in a lab with a hose in your mouth to measure your VO2 max, it just gives you a better estimate of your actual runs. There is no way to measure one's actual calorie burn so we use estimators. For most people, the broad formulas and HRMs give a good enough estimate.0 -
Intensity is a key point in this discussion that has not been well addressed.
It's key because in part the highly developed body will see a greater return on those physiological efficiencies at higher intensities. Take for instance the fact that the more basic strength you have to use for a movement, the less blood flow you get through that muscle. Generally, at about 50% of maximal strength limit the muscle is constricting tight enough with the effort that effectively zero blood flow is happening at contraction. This means 2 things for fit vs. non-fit. At a set pace, the fit body is using a lower % of strength and can rely on greater blood flow to the muscles. This is in addition to an already higher ability to deliver blood to the muscles via a more developed support system.
Why would this matter in the workout? It actually means very little..... in the workout
However, when we consider the recovery phase, where MOST of the calorie burn happens for intense exercise, the difference is dramatic. The non-fit person has to maintain a higher heart rate, oxygen intake, etc. during the recovery phase to replenish the muscles as they had to use more glycogen stores and have an inferior ability to replenish it. IE that workout that had you beat all day and sore for 2 wouldn't even register to a pro athlete. Even more so, as a more intense input gets a more intense response from the body in healing/building, the not-fit person's body will be building muscle and infra-structure in response at a much higher degree than the fit person as it simply wasn't nearly as intense for them.
Picture the Corvette vs. Volvo analogy. Run that Volvo to it's very limits for 20 laps around a racetrack, then have the Corvette match that pace for 20 laps. What are you left with? A fun day in a Corvette and a few gallons of gas burnt, and a Volvo that has significant tire wear, a stressed cooling system, smoking brakes, etc. etc. It's not the cost of the gas on track, it's the cost to get it back to healthy after the race. Now on top of that the Volvo mechanic recommends better tires, shocks, brake pads, etc. so that it will be able to take that pace better on the next track day. All additional cost that the Vette driver doesn't need to pay out (or you could say has already paid for)
This is why Tabatas and HIIT work as well as they do. It's not the calories burned in a few minutes, it's how many it takes to recover from that expenditure.0 -
stop over thinking it and go for a damn run.
seriously- it's not THAT critical.
Seriously, less talking more doing. If you don't get out there now you'll keep putting it off. Just go.0 -
Do people still use Heart Rate monitors? ha
If those 3 people ran 3 miles they wouldn't burn the same calories. You didnt say how fast they did it?!
Calculations like this are very generic and used as a average range to give a very average result. Before you put your heart rate monitor on, did you do a test to see what your maximum heart rate is? Please say you didn't do 220-your age? again, a very generic result!
IMO running for distance is a bye gone era. If you run 3 miles 3 times a week your bound to be good at it somewhere which would make your time decrease, why would you want to burn less calories than the week before?! Run for 30 minutes instead, you hit 3.5 miles at some point ans so on.
slow and long cardio is also a bye gone too, New studies show that HIIT and interval is the way forward and that Tabata training is quickest form of raising fitness levels (VO2 max). Get an iphone and get an interval training app. their cheaper, more effective and a lot more fun0 -
stop over thinking it and go for a damn run.
seriously- it's not THAT critical.
Seriously, less talking more doing. If you don't get out there now you'll keep putting it off. Just go.
I'm confused. Who's putting what off?
I personally like to understand the whys behind something, especially when it doesn't necessarily make sense to me.0
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