# Heart rate vs. calorie burn

1. Mar 11, 2015

### Evil Bunny

Is there a direct correlation between calorie burn and heart rate?

If an athlete and a couch potato each weighed 175 lbs and ran a mile in 10 minutes, would they burn the same amount of calories?

I would assume the couch potato would have a much higher heart rate during this event. Does that make any difference at all?

2. Mar 11, 2015

### Pierce610

The main duties of heart are to regulate temperature keeping it constant, to bring O2 and to bring away CO2.
So O2 increases if heart rate increase. But O2 reacts and burns calories if there is a request of muscular force.
I think then there is a correlation if we want get motion of body, for example, but yet one can have a patology with very frequently beats without do any movement.

3. Mar 11, 2015

### Staff: Mentor

This should help answer.

http://www.mayoclinic.org/healthy-living/weight-loss/in-depth/metabolism/art-20046508?pg=2

4. Mar 12, 2015

### Evil Bunny

Thanks for the replies...

I guess what I'm trying to find out is an answer to a more specific question.

In physics, if you move an object with a specific weight (175 lbs in my example) at a specific rate (6 mph in my example), there is a specific energy requirement.

Energy is measured in joules, and a calorie is just a certain amount of joules... Therefore, I would say that both subjects in the example would burn the same amount of calories regardless of how fast their hearts are beating.

But this is in conflict with things like heart rate monitors that tell you how many calories you have burned during your workout based on your heart rate.

So... do the athlete and the couch potato (who weigh the same) burn the same amount of calories after the 10 minute mile or don't they? Their hearts were beating at much different rates, but the energy requirement (calories burned) seems like it should be the same.

5. Mar 13, 2015

### Choppy

So the question you want to ask is whether a fit individual is more efficient than a non-fit individual.

I suspect the answer is yes.

EDIT: But now that I think about it, that might just be a conclusion that results from a circular definition.

6. Mar 13, 2015

### Staff: Mentor

7. Mar 18, 2015

### Evil Bunny

I understand that an athlete will have a higher metabolism than a non-athlete. And if they were each sitting on a couch next to each other, the athlete would burn more calories while they're both resting based on metabolism alone.

But what happens with calorie burn when they both run 6 mph for 10 minutes (remembering that they weigh the same)? And how is it related to heart rate?

Are we saying that, since the athlete has a higher metabolism, he will burn more calories?

Further, if each of them were wearing a heart rate monitor that estimated their calorie burn, would this device be in agreement with that idea?

It seems to me that the non-athlete would have a much higher heart rate than the athlete during this event, and his heart rate monitor would tell him that he burned more calories than the athlete did.

Both of these ideas can't be correct.

8. Mar 18, 2015

### Staff: Mentor

The answer is in the link I gave you, muscle burns more calories. You are referring to one person as an athlete, so I would assume that you are inferring that the athlete has more muscle than the *couch potato*. A heart rate monitor cannot tell the difference between the two people and could not give you an accurate estimate of calories burned.

9. Mar 25, 2015

### Martin Evans

"In physics, if you move an object with a specific weight (175 lbs in my example) at a specific rate (6 mph in my example), there is a specific energy requirement.

Well, no. Only accelerating an object requires energy. In theory, if you could run without raising and lowering your centre of gravity , on a flat plane you would expend little energy. I think that the heart rate required to keep up any level of activity is just a measure of your body's efficiency. i.e. fitness. I know that, when I am 'fit' my resting heart rate drops significantly.

10. Mar 27, 2015

### Evil Bunny

Good point... I guess gravity is the only reason we need to expend energy on a steady run in the first place.

So, what I learned from this thread is that heart rate monitors are completely useless if you're interested in calorie burn. Interesting...