THIS is why HRMs have limited use for tracking calories

Chevy_Quest · October 2013

Great Thread - Thanks for the info Adzak!

ninerbuff · October 2013

So if an HRM isn't good for interval training, isn't good for lifting weights, and is only good for steady state cardio, then what's the purpose of using one? I thought about getting one but now I'm reconsidering.
I currently jog for 3 minutes and walk for 2 for 2 miles....building up for a continuous run of the whole 2 miles. I also do P90X Lean schedule on alternate days of running. Will an HRM work for calculating calories for this or do these 2 types of exercise fall into the ones that render it useless?

As mentioned HRM's are limited to steady state cardio for accuracy. Easiest way I explain it to clients is one could wear an HRM to a scary movie. Heart rate increase in it obviously will increase and maybe stay throughout the whole movie. Does that mean just sitting there watching it means you burn more significantly more calories compared to watching a movie that isn't scary? Think about it.
Estimation of calories burned is just that, an estimation. Being consistent with it will give one a sense of what intake they need to adjust to for energy needs.

A.C.E. Certified Personal/Group FitnessTrainer
IDEA Fitness member
Kickboxing Certified Instructor
Been in fitness for 30 years and have studied kinesiology and nutrition

TheSink · October 2013

There's always someone on here just waiting to burst a person's balloon animals. If you people spent half as much time trying to come up with a new invention as you do trying to kill the inventions already created (i.e., HRM's), this world wouldn't be such a crappy place.

Chevy_Quest · October 2013

So if an HRM isn't good for interval training, isn't good for lifting weights, and is only good for steady state cardio, then what's the purpose of using one? <<snipped>>

As mentioned HRM's are limited to steady state cardio for accuracy. Easiest way I explain it to clients is one could wear an HRM to a scary movie. Heart rate increase in it obviously will increase and maybe stay throughout the whole movie. Does that mean just sitting there watching it means you burn more significantly more calories compared to watching a movie that isn't scary? Think about it.
Estimation of calories burned is just that, an estimation. Being consistent with it will give one a sense of what intake they need to adjust to for energy needs.

^^this good analogy!

heybales · October 2013

So if an HRM isn't good for interval training, isn't good for lifting weights, and is only good for steady state cardio, then what's the purpose of using one? I thought about getting one but now I'm reconsidering.
I currently jog for 3 minutes and walk for 2 for 2 miles....building up for a continuous run of the whole 2 miles. I also do P90X Lean schedule on alternate days of running. Will an HRM work for calculating calories for this or do these 2 types of exercise fall into the ones that render it useless?

Jogging and then walking isn't the type of interval training being referred to. The variance in your HR between those 2 probably isn't that great.

HIIT type, where you push anaerobically (just like lifting) for only 15-45 seconds, and then recover from 45-135 seconds, causes total non-steady state, and probably variances of 50-60 bpm HR.

Other interval types are also totally anaerobic to a lesser degree for maybe upwards of 1-2 minutes, then a 1-2 min recovery.

Those type being anaerobic and non-steady state will be inflated, the second not as bad. Because while you do have decent periods of bad estimates, it's balanced by periods of good estimates.

What you are doing with running and walking, no nearly as bad.

P90X is totally non-steady state, and many parts of it are anaerobic.

What you'll notice if you watch HR when doing a cardio workout, if you increase the workload (faster, more incline, ect) the HR will of course go up as expected. But it was an overshoot you might say for what was required. So you keep going for 2-4 minutes, and it'll drop back down to what is really needed for that workload, perhaps 5-10 bpm slower.

So now picture a workout where you never keep the same workload for 2-4 minutes, the HR never lowers back down to what is really needed for that level of work - in other words it's always inflated by 5-10 bpm. And that's for aerobic cardio. That's why it's going to be inflated.
Include lifting where the HR increase isn't even for the purpose of required oxygen, really inflated.

You'll get better calorie count using the MFP estimate if you truly match the speed given in the description (on avg) and did it flat, which is what it's based on.
Otherwise, use this. MFP and HRM would give you a gross figure, but use NET here to log and eat it all back.
http://www.exrx.net/Calculators/WalkRunMETs.html

But you can use the HRM to get a good idea you are still pushing as hard as you need to.
For instance, if after couple months you are still doing the same pace routine, but the avgHR dropped 20 bpm, it just got easier for your heart muscle. If you weigh the same it's the same calorie burn and workload for your other muscles at least, but that's likely not the case, you probably weigh less and should be going faster so the muscles get the same workout. And actually, for the heart to get a better workout, probably need to go even faster still.

Chevy_Quest · October 2013

This ^^^^ the post above - Very good explanation and totally logical! :drinker:

heybales · October 2013

There's always someone on here just waiting to burst a person's balloon animals. If you people spent half as much time trying to come up with a new invention as you do trying to kill the inventions already created (i.e., HRM's), this world wouldn't be such a crappy place.

Pardon us for helping people understand better the tool they are using doesn't do exactly what they thought it did.

And how in the world are we killing a HRM, that would be Heart Rate Monitor in case you didn't know, by talking about something it was never intended to do in the first place, estimate calorie burn.

Go drive your car in a lake. oh wait, you mean it's not a boat!

bekahlou75 · October 2013

So if an HRM isn't good for interval training, isn't good for lifting weights, and is only good for steady state cardio, then what's the purpose of using one? I thought about getting one but now I'm reconsidering.
I currently jog for 3 minutes and walk for 2 for 2 miles....building up for a continuous run of the whole 2 miles. I also do P90X Lean schedule on alternate days of running. Will an HRM work for calculating calories for this or do these 2 types of exercise fall into the ones that render it useless?

Jogging and then walking isn't the type of interval training being referred to. The variance in your HR between those 2 probably isn't that great.

HIIT type, where you push anaerobically (just like lifting) for only 15-45 seconds, and then recover from 45-135 seconds, causes total non-steady state, and probably variances of 50-60 bpm HR.

Other interval types are also totally anaerobic to a lesser degree for maybe upwards of 1-2 minutes, then a 1-2 min recovery.

Those type being anaerobic and non-steady state will be inflated, the second not as bad. Because while you do have decent periods of bad estimates, it's balanced by periods of good estimates.

What you are doing with running and walking, no nearly as bad.

P90X is totally non-steady state, and many parts of it are anaerobic.

What you'll notice if you watch HR when doing a cardio workout, if you increase the workload (faster, more incline, ect) the HR will of course go up as expected. But it was an overshoot you might say for what was required. So you keep going for 2-4 minutes, and it'll drop back down to what is really needed for that workload, perhaps 5-10 bpm slower.

So now picture a workout where you never keep the same workload for 2-4 minutes, the HR never lowers back down to what is really needed for that level of work - in other words it's always inflated by 5-10 bpm. And that's for aerobic cardio. That's why it's going to be inflated.
Include lifting where the HR increase isn't even for the purpose of required oxygen, really inflated.

You'll get better calorie count using the MFP estimate if you truly match the speed given in the description (on avg) and did it flat, which is what it's based on.
Otherwise, use this. MFP and HRM would give you a gross figure, but use NET here to log and eat it all back.
http://www.exrx.net/Calculators/WalkRunMETs.html

But you can use the HRM to get a good idea you are still pushing as hard as you need to.
For instance, if after couple months you are still doing the same pace routine, but the avgHR dropped 20 bpm, it just got easier for your heart muscle. If you weigh the same it's the same calorie burn and workload for your other muscles at least, but that's likely not the case, you probably weigh less and should be going faster so the muscles get the same workout. And actually, for the heart to get a better workout, probably need to go even faster still.

Thanks!

heybales · October 2013

Thanks!

I forgot to get in to your question of why you'd want to use a HRM if calorie count is possibly so bad and invalid for some workouts.

As you probably got the point - HRM main purpose is exactly what the name says - monitoring HR.

So especially intervals is it useful.
For really getting a benefit from most intervals, it must be so much of a workout for the heart and muscles, so it needs to reach a certain level.
If it doesn't, you don't get the improvements that workout could provide. You'll get some, but possibly not the same, nor not nearly as much as could have been gained.

Might view it as lifting. If you can squat 200 lbs 3 x 8, but you proceed to do your workouts with 50 lbs - gonna see much of any improvement?
It will only become difficult, possibly, if your muscles lose their strength and that level is now maintaining.

And even in lifting with that example, HR would show up that fact.
200 lb you'd probably end up pushing the HR in to the anaerobic HR zone.
50 lb might cause some spikes, but not nearly as high.

Now anyone could read their body for that extreme difference, and know why one is harder.

But it also can confirm if you are lifting on tired muscles, not getting as good a workout as you could. If your muscles are so tired that they can't push the HR as high as normal, you missed sleep, or perhaps that cardio workout day before took too much out of ya, ect. Now you know that if lifting was more important, don't do those things that impact it.

Same way the vast majority think they are doing HIIT just because they are pushing themselves hard. Doing that tired and fresh is very different, and HR will show up the difference.
And HIIT only has it's intended benefit if you reach that anaerobic lifting-like HR levels. If you don't, then you aren't getting the benefit you think you are. Even if you feel like you are pushing as hard as you think.
Might as will do SIT or regular intervals and get a different but still beneficial workout for the time and effort given.

And just as intervals provide a benefit by going hard and then easy, so that hard is really hard and see body improvement, and easy allows recovery, HRM can confirm your workout days follow the same method.

Hard days can truly be hard, when easier days are in between. So HRM can confirm that you keep the load light, but still active, on another workout.
For years that was called Active Recovery HR zone, but lately it's been called by the fad name fat-burning zone. Still a totally valid and useful training zone, increase blood flow, use the muscle, but don't add another load the body must recover from while it's already trying to recover from a hard workout day before.

TheSink · October 2013

Pardon us for helping people understand better the tool they are using doesn't do exactly what they thought it did.

And how in the world are we killing a HRM, that would be Heart Rate Monitor in case you didn't know, by talking about something it was never intended to do in the first place, estimate calorie burn.

Go drive your car in a lake. oh wait, you mean it's not a boat!

Remind me to scare you from the gutter, grampa.

_Zardoz_ · October 2013

Some people have far you'll much time on their hands

Manda_1986 · November 2013

That was a really interesting read thanks! People really do put too much emphasis on what HRM's say. I think you should take any "measurement" tool with a grain of salt.

While I have never been obese I have been overweight. At my heaviest I was 77kg. I am now 67kg and nearly at my goal. To fix this I taught myself about nutrition. Nutrition is the key to weigh loss along with exercise. Everyone sits around talking about the calories they are burning etc and how much they can eat. I think people need to look more at WHAT they eat. I was reading posts earlier from certain people that are trying to learn about how to lose weight. My advice to them is to educate yourself with good nutritional facts. No one needs to starve themselves or workout for 4 hours a day.

You need to fuel your body with the right foods and you will find that your calories will stretch sooo much further. Calculate your BMR and use that as a basis for what you should be eating in a day to maintain weight. Any exercise increases that number. Nothing is every going to be exact it is all just estimated and may take some trial and error. If you work out for example that 1600 calories a day will be your 500 deficit and you don't lose any weight for a few weeks/gain weight. Reduce the calories by 100 and repeat until you start to lose weight. That is what I did and it worked. Plus I am healthier and stronger from fueling my body with the right foods.

heybales · November 2013

Calculate your BMR and use that as a basis for what you should be eating in a day to maintain weight. Any exercise increases that number.

Actually, TDEE is what maintains weight.

BMR is what your body would like to burn sleeping all day on the most basic functions of life. Basal Metabolic Rate.
Even bed-ridden people if they wake up burn more than their BMR in a day, well, if they move. Though the awake brain burns more with more stimuli going on.