average heart rate vs calories

[mntlion]

Girl guide has been using a heart rate monitor for a bit now biking and ones in the past show calories burn, So this has to be a formula right ???

Average HR over an hour = ??? calories burnt. (her watch now just shows the current HR and average HR)

I know that other things will factor in like her size (145pounds and 5"4') and fat to muscle ratio, and bone density and lots of other things that I have not thought of yet, but overall does anyone know a basic formula to find this out?

thanks guys

[focus]

I'd think heartrate change would have to figure into the calories burned....

i'm sure those calculators figure calories burned at rest and then how calorie burnage increases along with percentage heartrate increase. I have a resting heartrate of around 60, at 80 I'm sure I'm burning more calories than somebody whose resting heartrate is 75.

(I don't know that much about these things...just speculating along with you.)

edit: quick google search seems to indicate that the calorie burned calculations are derived from percentage to target heart rate, figuring in body mass somehow too...

here's one for horses: Y = e^(3.20 + .0065x); where x is the speed is meters/minute, and Y equals the calories expended per kg per minute.

ugh....finals procrastination rears its ugly head...

[theferret]

My understanding is that this gives you an estimation, with a big margin of error. For instance, you burn around 50% more calories per hour at the same heart rate on a rowing machine as you do mountain biking. If you mostly do the same couple things for exercise though (say run and ride) the watches are internally consistent - if you are trying to lose weight and you track calories eaten and "calories burned" on a watch, you can adjust to reach your decided rate of weight loss. So if you are losing a pound a week and want to lose 2 a week, you cut food eaten by 500 calories a day, or add 500 calories of exercise. Probably the best thing the watch does is keep you from working out too hard and losing muscle if you are dieting, or helping you do interval training if you are after CV fitness. PolarUSA has some info on their web site, as does concept2 (rowing machine manufacturer, rowers are big into heart rate training).

[yentna]

I wish I knew more about it, wear my HR monitor religiously but am never quite sure it's accurate. And if it is, then why. So, sorry, no help here.

[fluffballs]

Calories burnt is based on the amount of work done, run a mile, walk a mile you burn the same amount of calories. This is how those treadmills can calculate your calories burned, fairly accurately, just off the distance you've traveled. Using HR to calculate Kcal usage is totally inaccurate because depending on the individual HR rate can be totally different for a given work load. HR is usually a good determination of intensity of work, which is the most important factor to aerobic fitness (how efficiently your body is able to use the fuels you give it). Generally you want to be working out at a minimum of 70% of you maximal HR, easy estimation is 220bpm - your age. If you're 25, your max HR is 195 beats per minute.

P.S. you usually burn 100 Kcals per mile

[bdog]

Calories burnt is based on the amount of work done, run a mile, walk a mile you burn the same amount of calories.

Not quite so. You are quite correct that HR is not a good measure of Kcal burned. However, the amount of calories (Kcal) burned will differ greatly as mentioned in Bullet's post depending on whether one is trained and what they are doing. Cycling for an hour at a specific HR will burn a different amount of Kcal than running for an hour or say swimming or nordic skiing.

[runethechamp]

Not quite so. You are quite correct that HR is not a good measure of Kcal burned. However, the amount of calories (Kcal) burned will differ greatly as mentioned in Bullet's post depending on whether one is trained and what they are doing. Cycling for an hour at a specific HR will burn a different amount of Kcal than running for an hour or say swimming or nordic skiing.

You're not giving any points here contradicting what he's saying, and he's actually correct, at least if you have a little bit of pace on your walking. It's going to take you longer if you walk, but you'll get about the same result per distance walked.

[Max Gosey]

My stairmaster at home goes from intensities of 1 to 17, saying that 1 is like a 12 minute mile and 17 is like a 6:30 or so mile. I select "manual program" and when I'm in good shape, I'm on that thing for about 3 consecutive 15-minute periods, each of which starts with asking for a weight, presumably to calculate calories (at an average intensity of 16.98, I supposedly burn 324 calories, which equates to 2.3ish miles... in 15 minutes).

Do the math: this is 1300 calories per hour. When I was in great shape before J-Hole, I would do two 60-minute days per week, one 45-minute day, and two 30-minute days, and I'd be freakin' tired at the end, but not necessarily to the point where I couldn't go anymore. Didn't seem like I had done 1300 calories' worth of work... My heart rate was usually about 165 to 170 at the end of that (I'm 19) and was pretty consistent throughout those long intervals.

Does the machine lie, or was I just a fucking robot that could go forever?

What is you guys' experience with stairmaster in terms of heart rate vs calories? It seems like I burned a hell of a lot more calories per minute at the same HR on the stairmaster (according to the machine) as I do on an elliptical/treadmill.... Which I suppose would refute the correlation between absolute caloric burning (as opposed to relative) and heart rate...


What I've been trying to do lately on the elliptical is maximize the "calories per minute" (one of the displays on the machine that fluctuates with the amount of force/speed you input) at the lowest heart rate possible, both to get in the best CV shape and to burn the most fat. Can this really be regulated, or am I psyching myself out by trying to alter this ratio? (In other words, is this ratio constant after several weeks of training?)

Lots of good issues in here...

[theferret]

Any exercise physio's out there? I'm not, but I've read a fair bit. Feedback from someone who knows would be great.

My understanding is that working out to lose weight and working out to gain fitness are done differently.

1) To lose weight, you do a lot of low intensity cardio (under 65% of max heart rate (MHR) - this is really easy). The theory is you can only metabolise so much fat per hour, so if you work out too intensely you wind up breaking down muscle. Better to do 2 hours at 65% than one hour at 80%. Then you throw in a small amount of very intense weightlifting a couple times a week (i.e. maxing out at 3 or 5 reps on squats, deadlifts, bent-over rows), again in an effort to preserve muscle mass.

2) For CV fitness, you do interval training - short bursts of really high intensity (over 90% of MHR) sprints with easy rests in between.

3) The really painful workouts (like running an hour at a fast pace) seem to be the worst of both worlds- its easy to break down muscle, and usually aren't intense enough to stimulate the positive CV changes you are after.

I'd like to know if this is correct or not - for years I did the third option, figuring it must be the best since it involved the most suffering, but lately I've had MUCH better results with less time and misery combining 1 and 2 depending on what I need to accomplish.

[theferret]

Also, the exercise machine that would give you the best calculation of calories burned on its display would be one of the concept2 rowers - it measures how much energy is put into the flywheel, which is independent of user size/fitness. Its actually pretty slick, the flywheel is a fan and the computer measures how fast it accelerates and decelerates. Indoor rowing is incredibly boring so the rowers are big on remote training (racing against their friends over the internet), and they need a way to calibrate for manufacturing differences in the fans. Supposedly the computers in the rowers are good enough to compensate for altitude and even dust buildup on the fans.

If I was trying to get an accurate measurement of calories burned, I would compare my watch to a concept2 rower for an hour to get a baseline, and then find out the calorie/hour ratio of rowing versus other cardio exercises.

But, I don't think the absolute numbers are important - if you maintain the same diet and its not working, increase the calories burned on the watch each week.

[The AD]

2) For CV fitness, you do interval training - short bursts of really high intensity (over 90% of MHR) sprints with easy rests in between.

3) The really painful workouts (like running an hour at a fast pace) seem to be the worst of both worlds- its easy to break down muscle, and usually aren't intense enough to stimulate the positive CV changes you are after.

I'd say your number two would be called "anaerobic training" and three would be "aerobic training." From another website the purpose of aerobic training is to: "improve maximal aerobic power or the maximal amount of oxygen the body can obtain and utilize per unit time (Vo2 max.)" The purpose of anaerobic training is to "progressively improve the body's ability to tolerate oxygen debt, increases stores of ATP and muscle glycogen." Aerobic training builds endurance, anaerobic training improves your ability to sprint and do other short duration, explosive activities.

I don't really think you can say which of these is "better." It all depends on what you're trying to achieve. A marathoner of Tour de France cyclist is going to rely on primarily aerobic training. A 100 meter runner is going to do almost exclusively anaerobic conditioning.

[Vinman]

Calories burnt is based on the amount of work done, run a mile, walk a mile you burn the same amount of calories.

Not even close. You're telling me that running a 7:00 pace would be the same calories burnt as walking?

No way do I believe that. Calorie expendature is based on exercise intensity.

The following was taken from my old Ex Phys Text:

walking 3.5mph 5.0 kcal/min male 3.9kcal/min female
running 7.5 mph: 14.0 kcal/min males 11.0 females
10.0 mph: 18.2 kcal/min male 14.3 kcal/min female
swimming 3.0 mph 20.0 kcal/min male 15.7 kcal/min female

treadmills use an average based on the speed the machine is set at. Some of the better ones use the person's weight and the speed to come a bit close but those are still a general figure.


And 220 minus your age is a very rough estimate of max HR. For me 220 -34 is a max HR of 186. This is low for me. My max HR is more like 189-191 depending on what type of exercise I am doing. i.e. I can get a higher HR while running that I can while cycling.

[Viva]

1) To lose weight, you do a lot of low intensity cardio (under 65% of max heart rate (MHR) - this is really easy). The theory is you can only metabolise so much fat per hour, so if you work out too intensely you wind up breaking down muscle.

Low intensity (aerobic) excercise in the trained individual will preferentially burn fat, so over time and with appropriate eating habits, one can lose weight this way.

With respect to too much intensity breaking down muscle, while prolonged, exhaustive endurance exercise is capable of inducing skeletal muscle damage and temporary impairment of muscle function, I think you're talking about anaerobic excercise. In this case, the load exceeds the person's ability to perform aerobic work and so you recruit skeletal muscle, as well as liver, glycogen as the primary energy source. Creatine phosphate can also be used to supply muscle energy. This is a very simplistic explanation, but I think that I'm addressing your questions.

[Viva]

Girl guide has been using a heart rate monitor for a bit now biking and ones in the past show calories burn, So this has to be a formula right ???

Why does this matter? Does she want to replentish the calories burned either during the ride or after in the form of engergy drink, powerbar, etc.?

[Orange Julius]

Not even close. You're telling me that running a 7:00 pace would be the same calories burnt as walking?

No way do I believe that. Calorie expendature is based on exercise intensity.

There is also the benefit of the increased metabolic rate post-exercise when doing intense workouts. Your body does not stop burning calories once you stop exercising, and in fact consumes a considerable amount repairing itself and maintaining a higher HR for a period of time. It is often beneficial to finish a long run with a few quick sprints to maintain a good burn after the exercise. Overall, you will burn considerably more energy running hard than going for a stroll.

Heart rate monitors are good motivators, but I don't always wear mine. Sometimes I just like to run.

[Mofro261]

Not even close. You're telling me that running a 7:00 pace would be the same calories burnt as walking?
No way do I believe that. Calorie expendature is based on exercise intensity.
The following was taken from my old Ex Phys Text:

walking 3.5mph 5.0 kcal/min male 3.9kcal/min female
running 7.5 mph: 14.0 kcal/min males 11.0 females
10.0 mph: 18.2 kcal/min male 14.3 kcal/min female
swimming 3.0 mph 20.0 kcal/min male 15.7 kcal/min female
.

Well hold on here... Check your math, your phys ed book formula actually gives greater calories burned per mile to running 7.5 mph vs. 10 mph.

The bigger advantage to running over walking the same distance is the calories you will continue to burn AFTER you've finished, that and finishing quicker.

EDIT: OJ beat me to it- what he said.

[Vinman]

Well hold on here... Check your math, your phys ed book formula actually gives greater calories burned per mile to running 7.5 mph vs. 10 mph.

The bigger advantage to running over walking the same distance is the calories you will continue to burn AFTER you've finished, that and finishing quicker.

EDIT: OJ beat me to it- what he said.

The error here is duration of exercise

The calories per mile is not the correct measurement because of exercise duration.

18.2 kcal x 6 min = 109 kcal/mile
14.0 kcal x 8.5 = 119 kcal/mile

so yes you are burning more calories per mile, but it is taking you 2.5 minutes longer to complete the mile.

This is the whole basis of a fat burning exercise. A longer slower distance will burn more calories that a shorther more intense distance because of the duration factor.

Also I think that calorie expenditure is not on a linear scale. The human body can only go just so fast at a given activity. And calorie expenditure is eventually limited by how much O2 we can process while exercising. (VO2 max). Your metabolism increses with exercise intensity, but your O2 consumptionis limited, of which VO2 max is the peak.

[fluffballs]

Not quite so. You are quite correct that HR is not a good measure of Kcal burned. However, the amount of calories (Kcal) burned will differ greatly as mentioned in Bullet's post depending on whether one is trained and what they are doing. Cycling for an hour at a specific HR will burn a different amount of Kcal than running for an hour or say swimming or nordic skiing.

The second part of you statement is correct, different modes of exercise burn calories at a different rate, why's that? because you're doing a different amount of work. In addition if you train by swimming to perform in running, your swim VO2max may improve, you're not likely to see much improvement when testing in running (specificity of training). You're using different muscle groups in different ways, not to mention you may be using different energy systems, though even if both are endurance activities you'll see a difference.

walking 3.5mph 5.0 kcal/min male 3.9kcal/min female
running 7.5 mph: 14.0 kcal/min males 11.0 females
10.0 mph: 18.2 kcal/min male 14.3 kcal/min female
swimming 3.0 mph 20.0 kcal/min male 15.7 kcal/min female

Notice that everything is kcal/min, sure you're going to burn more kcal/per minute running a 7 minute mile than walking a mile in a 30 minutes, but that's becuase you're performing the same amount of work in a much shorter time. And the amount of kcal/min burned for that 30 min walk is less, but you've got more minutes. The Rough estimate is 100 kcal/mile.

The 220 - your age = Max HR thing is also rough, but fairly accurate, usually within 10bpm. But it's meant to be a rule of thumb for the general public, my 65 year old dad hit 198bpm while climbing Kilamangaro. I'm not sure whether that should scare the crap out of me or be really encouraging. We have a history of heart disease in our family, that should have killed him.

Sorry, I took my exercise physiology final yesterday, and graduate with a B.S. in Sports Medicine Saturday, I don't want to throw too much bs out there when there are some pretty simple standards. If you really want to know all about your personal capacities you can pay a lot of money and do some tests, but unless you're training for the olympics just take the FREE standards.

[Vinman]

Back to the original question

Mtnlion here is a simple calcualtor for estimating calories burnt. Just put in weight, duration of activity and type of activity.

For get about the HR thing. HR varies too much between individuals to be able to accurately estimate how many calories will be burnt for a given duration.

opps forgot the link

http://www.hsc.edu/fitness/calculators/calories.html

[fluffballs]

[/QUOTE]This is the whole basis of a fat burning exercise. A longer slower distance will burn more calories that a shorther more intense distance because of the duration factor.

Also I think that calorie expenditure is not on a linear scale. The human body can only go just so fast at a given activity. And calorie expenditure is eventually limited by how much O2 we can process while exercising. (VO2 max). Your metabolism increses with exercise intensity, but your O2 consumptionis limited, of which VO2 max is the peak.[/QUOTE]


A longer slower distance will not burn more calories if you're doing the same amount of work. However, a longer slower workout (over an hour) will be aerobic metabolism burning more calories from fat, as opposed to carbs or protein. You get percentages of caloric engergy from carbs, fat, and protein depending on what type of exercise you're doing, though they're on a continum.

as mentioned above, you do continue to burn calories after exercise depending on intensity and duration. Your body is still working, increased HR increased Breathing rate, increased temperature.

As far as best exercise per minute, swimming, look at the numbers presented earlier. You're using your whole body, that requires a lot of energy.


edit: to fix quote

[Vinman]

A longer slower distance will not burn more calories if you're doing the same amount of work. However, a longer slower workout (over an hour) will be aerobic metabolism burning more calories from fat, as opposed to carbs or protein. You get percentages of caloric engergy from carbs, fat, and protein depending on what type of exercise you're doing, though they're on a continum.

as mentioned above, you do continue to burn calories after exercise depending on intensity and duration. Your body is still working, increased HR increased Breathing rate, increased temperature.

As far as best exercise per minute, swimming, look at the numbers presented earlier. You're using your whole body, that requires a lot of energy.


edit: to fix quote

Work is a function of time and can be a function of power. Time = duration. More duration = more calories burnt for a specific intensity at a specific activity.

You can impact the amount of work done by either doing the activity longer or doing the activity faster.

So you will do more work if you run faster or run longer = more calories burnt

To burn the same amount of calories by walking you would have to walk a very long time.

For example walking for 1 hr at 3.5 mph for a 150 lb male would be about 345 calories

1 hr of running at 7 mph/8.5 min/mi would be about 810 calories

To eqaul thing out this person would have to walk for 140 minutes(805 calories) to expend the same amount of calories.

edit and this is not answering mtnlion's question, let's get back on track, besides ex phys makes my head hurt.

[Mofro261]

Work is a function of time and can be a function of power. Time = duration.

Wrong. Time = Money.

Work is disfunctional.

If you like spending more time spent at work, hey more power to yah.

[Viva]

The human body can only go just so fast at a given activity.

Yeah, but I don't think it has anything to do with O2 or caloric expenditure. The heart's the limiting factor here, more specifically, the coronary blood supply and delivery of oxygen to the myocardium. Skeletal muscle craps-out to prevent the development of a progressive myocardial ischemia during maximum exercise, i.e., cardiovascular function/fitness limits maximum exercise capacity.

[Vinman]

Yeah, but I don't think it has anything to do with O2 or caloric expenditure. The heart's the limiting factor here, more specifically, the coronary blood supply and delivery of oxygen to the myocardium. Skeletal muscle craps-out to prevent the development of a progressive myocardial ischemia during maximum exercise, i.e., cardiovascular function/fitness limits maximum exercise capacity.

The main limiting factor in exercise for trained people is VO2 max. The fitness of the heart itself has less to do with it. I agree that skeletal muscle craps out way before cardiac muscle, no contest there. But in aerobic exercise for trained people, VO2 max is really the determining factor. If you can consume the O2 to maintain the exercise intensity then everything else isn't relevant.

For the untrained it can be more of a skeletal muscle fatigue that prevents continueing exercise before the aerobic systems shut down

Yes there are some other factors at play like, availability of glucose, dehydration, accumulation of metabolic by products and failure of the the muscles ability to contract.

[homerjay]

Work is a function of time and can be a function of power. Time = duration. More duration = more calories burnt for a specific intensity at a specific activity.

Work is a force applied over a distance. Power is work over time. So the person running 1 mile is doing the same work as a person running 1 mile. The runner has more power since it is a shorter duration.