Low Calorie Burns on HRM...and my TDEE

yankeedownsouth

I'm curious about this. I seem get relatively low calorie burns for the activity I do. Numerous times, my friends will comment that my burns for walking/running/hiking etc seem low to them compared to what they earn for the same amount of time doing the same exercise. I've noticed this as well. I use a HRM, so I'm pretty sure my numbers are accurate. Of course, most of my friends use HRMs too, so I believe theirs are accurate as well. I just think I may be a "low burner," if such a thing exists.

This is all fine with me, but it does make me wonder if it would affect my TDEE. I’m using the online calculators to figure my BMR and TDEE; if I tend to burn fewer calories for my activities, wouldn’t my BMR and TDEE then be lower as well? I would imagine this would affect the number of calories I should be eating each day.

I just started EM2WL one week ago. I snuck a peak at the scale today, and I’m up 1.5 pounds. I realize this could be from a number of reasons, but I have to admit, I’m very nervous about eating 1800 calories a day. I’d like to lose 3 or 4 pounds – or at the very least lose fat and gain LBM. So going up this much in a week is causing me stress. I’m not going to make any decisions until Feb 1, but I’m still nervous…

Opinions?

holleysings

What HRM do you have?

GoGoGadgetMum

I guess heart rate readings are quite unique to people and is connected to their cardio health etc. I can keep mine quite high for a
Good time and my trainer used to comment on it. But my friend had a weird thing that the harder the workouts hers would drop. Might be to do with blood pressure, but I'm no expert on it.

Have you tried using your friends for a workout and see if they record a similar burn on the same activity?

sagj

Are you smaller than your friends? If you have only a couple pounds you want to lose compaired to friends who have more or if you are just more petite it could absolutely cause a difference in burn amounts. I'm on the other end of the spectrum since I'm taller and bigger than most of my friends and that is what I've noticed, just in reverse

Greenrun99

the bigger you are the more you burn.. you may do 45 minutes of cardio with your HR in the upper 80% and burn 300 calories, someone who has 40 lbs to lose can do the exact same with their HR in the upper 80% and burn 700.. More energy to move.

LBNOakland

Good question! I alos notuce that MFP gives me a higher count from the elliptical than my machine says. I figure the machine is more accurate so I use it. My weight is input into both but MFP soesn't have a clue what intensity I am working at! Obviously, not high enough!! LOL:yawn:

yankeedownsouth

What HRM do you have?

Polar FT60

yankeedownsouth

Thanks for the replies! I'm pretty average - 5'7" and 140 pounds. My friends (on MFP) that I've compared myself to are typically fit and sometimes smaller than me.

Strange...maybe I'm a special little snowflake after all...

holleysings

Thanks for the replies! I'm pretty average - 5'7" and 140 pounds. My friends (on MFP) that I've compared myself to are typically fit and sometimes smaller than me.

Strange...maybe I'm a special little snowflake after all...

Looks like you have a great HRM! Why don't you have one of your similarly sized friends use it and see if they get a lower burn than normal too?

natini

I have a Polar and I find that when I am on the treadmill I burn about 100 calories for every mile. If you are nervous about your TDEE why dont you use the online calculator and set it to sedentary. Use that calorie goal and add it your typical calories burned in a week from your HRM to get your TDEE. I think that will work.

yankeedownsouth

I just walked three miles at 4mph and only burned 160 calories. My calorie burn for the same distance has decreased over the last couple months so it might just be that I've gotten too used to this exercise. I'd change it up, but I NEED to walk my dog or he'll drive us all mad!

heybales

So you have a HRM with VO2max stat and I believe the Fitness test - have you done that since entering in lower weight? Or every month anyway?
And properly - first thing in the morning after a restful night after a rest day?

If not and you just entered in lower weight, it will appear you are less fit, because your VO2max automatically goes up as your weight goes down - with no improvement in actual fitness.

Why?

Because VO2max is mL per KG per min. It is a stat expressed per weight.

Say your's was 40 @ 67 kg, that means you could process max 2.68 L/min of O2 to burn carbs/fat and provide energy, calories.
You drop to 60 kg, and say that 2.68 L/min is the same because you got no improvement in your cardiovascular system, VO2max becomes 44.7 mL/kg/min.
12% increase in VO2max merely by losing weight.

So that means if you kept a pace the same as you used to do, you now have a HR that can beat lower to provide that same amount of oxygen required. Why, because you weigh less, so less effort to move you, even though you didn't increase fitness, and walking you didn't increase efficiency.
Most people have walked their whole lives and don't make much improvement in efficiency after age 6, teenage years getting worse. Actually, without a physical defect causing problem, most people walk the same pace with the same level of efficiency.

Such that the formula's for calculating calories burned on a treadmill at set speed are more accurate than a HRM.

http://www.myfitnesspal.com/topics/show/774337-how-to-test-hrm-for-how-accurate-calorie-burn-is

Regarding your last comment, your calorie burn for the walk has stayed exactly the same.
Your ability to provide the oxygen has improved to supply that exact same energy, so your HR is lower.
Your HRM is confused and thinks that means less effort, therefore less calorie burn.

HRM is wrong.

140 lb at 4 mph for 45 min, assuming 1% incline, would be 272 calories gross.
Your NET above and beyond what you would burn just resting is 222.
Your NET in the diet world of accounting for calories would be 272 minus your non-exercise TDEE / 1440 * 45.

http://www.exrx.net/Calculators/WalkRunMETs.html

That's why an updated fitness test on it is needed, your VO2max went up even beyond what a loss of weight would cause.

And your friends have the same model?

Because the Polar's that don't have VO2max are calculating that based on your BMI. It's assumed the more unhealthy your BMI is, the worse your VO2max is.

So on those cheaper Polar's, if you are heavy but fit, you really get underestimated calorie burn.
But if you are thin and in terrible fitness shape, you get overestimated burns.
If the HR was to stay the same.

Yep, the only place weight comes into play in the HRM's is in calculating other factors that are actually used in estimating calories burn.

For any that find that hard to believe, look up a past workout on your HRM and see what the avgHR and calorie burn was.
Now increase the weight by 20 lbs and go do it again, trying to hit that AHR and time, and see what the calorie burn is.

If you want more detail on that then you'd ever want to know, just wrote up comparing my last 2 VO2max tests, and what HRM's are trying to do.

http://www.myfitnesspal.com/blog/heybales?month=201301

Oh, and your friends, and yours, may have very bad defaults in it for everything, nothing tweaked for you specifically.

heybales

Separate point.

If you do a lot of strong cardio, and good training with it, you can indeed improve your body's resting efficiency such your RMR can be lower.

My RMR was about 200 calories below what was estimated based on tested Lean Body Mass. And the formula's for that, based on real LBM, are within 5% in the studies, so I was way outside the curve.

And I was eating well above my higher estimated BMR/TDEE/Deficit amount, so it was no problem of eating too little and suppressing metabolism.

What was interesting I thought, my resting oxygen usage was right at what is considered avg. 3.5 mL/kg/min.

But that slowdown was after triathlon training, so lots of good cardio.

yankeedownsouth

Haybales, thank you! That was very helpful. You had a great point about the fitness test. I haven't done one lately; in fact, it's been probably 3 months. I wish I had read your post last night before I went to bed, because this morning was the perfect day to do it. Now, after two cups of coffee, not so much! But I'll do it next Saturday for sure!