Heart rate vs caloric expenditure

[bifodus]

I realize that how well we distribute oxygen to our muscles is determined by our heart rate, our stroke volume, and our oxygen saturation. What I'm curious about, though, is do those latter two variables remain relatively constant for an individual of a given level of fitness? Restating in more practical terms: Can the intensity of a given workout be entirely determined by my heart rate? Will I burn just as many calories keeping my heart rate at 160bpm for 30 minutes while running as I would by keeping it at 160bpm for 30 minutes by rigorously flossing my teeth? Just doing a single exercise like running gets tedious for me, so I'm trying to develop a more spontaneous routine (don't worry, it won't include rigorous flossing) where my only benchmark is heart rate. Is this a worthwhile approach?

[YoMaMa84]

good question, but I think the process of using more muscle to do the work burns more calories in the long run. I dont think being startled and your HR goes up to 160 for a minute burn more calories than if you ran for a minute while youre HR is at 160.

plus, I understand why people will say cardio gets boring, but try to do other things to make it more interesting....or stop thinking about it. eitherway, if you want the result, you have to do the work.

[wnc817]

I realize that how well we distribute oxygen to our muscles is determined by our heart rate, our stroke volume, and our oxygen saturation. What I'm curious about, though, is do those latter two variables remain relatively constant for an individual of a given level of fitness? Restating in more practical terms: Can the intensity of a given workout be entirely determined by my heart rate? Will I burn just as many calories keeping my heart rate at 160bpm for 30 minutes while running as I would by keeping it at 160bpm for 30 minutes by rigorously flossing my teeth? Just doing a single exercise like running gets tedious for me, so I'm trying to develop a more spontaneous routine (don't worry, it won't include rigorous flossing) where my only benchmark is heart rate. Is this a worthwhile approach?

I am not a scientist. But I believe that calorie expenditure depends on more than your heart rate. For example, when you use your muscles, they begin to use their stored energy, and that energy has to be replaced. Also, people that are in good cardio-vascular shape tend to have lower resting heart rates than people that are out of shape.

I think there is somewhat of a correlation between heart rate and calories burned, but I think other factors are involved as well.

I guess if what you are asking is a replacement for LISS, you could do HIIT for a shorter period of time in the day and maybe get similar results. And it doesn't matter what "kind" of cardio you do, as long as you do it.

[ejthomp]

Now that is a darn good question.

I do several types of cardio...treadmill...elliptical...basketball...spi n class...

I try and wear my heart rate monitor for all of them.

No science behind my answer other than to say that if my heart rate is 140 and above, I get a good sweat going regardless of the method.

My inclination is to say they must all be the same in terms of caloric expenditure.

[Wowzer]

I realize that how well we distribute oxygen to our muscles is determined by our heart rate, our stroke volume, and our oxygen saturation. What I'm curious about, though, is do those latter two variables remain relatively constant for an individual of a given level of fitness? Restating in more practical terms: Can the intensity of a given workout be entirely determined by my heart rate? Will I burn just as many calories keeping my heart rate at 160bpm for 30 minutes while running as I would by keeping it at 160bpm for 30 minutes by rigorously flossing my teeth? Just doing a single exercise like running gets tedious for me, so I'm trying to develop a more spontaneous routine (don't worry, it won't include rigorous flossing) where my only benchmark is heart rate. Is this a worthwhile approach?

No, heart rate does not correlate well with energy expenditure when comparing different exercises. Heart rate is actually pretty useless as a tool for estimating energy expenditure during exercise as it changes from day to day due to environmental factors (stress, hydration, what you've eaten, ******t temperature and more). One day you may be able to run at 12km/hr at 160bpm, the next day only run 10-11km/hr at 160bpm. Your energy expenditure will be different but heart rate the same.

As some people have touched on, heart rate and energy expenditure is also affected by how much muscle mass you are using for a particular exercise. Heart rate response is related to the % maximum intensity (or power output) for the muscles being used.

As an example, a person using an arm cycle (picture attached) or riding an exercise bike. The arms maximum power output is significantly less than the leg muscles (the arms being smaller and weaker than the legs). If you were to exercise at the same heart rate on both machines, you would be producing much more power (and therefore higher energy expenditure) on the bike as your leg muscles are significantly larger. So for maximum energy expenditure for a given heart rate, you would ideally find an exercise that uses as much muscle mass as possible.

Fitness also changes the equation. As you get fitter, heart rate will be lower for the same power output, but energy expenditure is the same.

Another thing to consider is blood flow. An exercise that impedes blood flow will cause a higher heart rate, as the heart has to beat more and harder to increase blood pressure enough to force blood flow through blood vessels in contracting muscles. This is why people who wear heart rate monitors when doing weights find their heart rate is always quite high. Unfortunately, 'bodybugs' and heart rate monitors will always significantly over estimate energy expenditure on people doing weight training.

[kc_shuffle]

using bigger muscles groups during cardio will burn more cals.

running and cycling are good ones as they use bigger muscles.

whereas flossing your teeth will use smaller muscles and burn less cals even if you keep the same heart rate as running /cycling.

go for the burn.