WTF is wrong with my HRM?

nytrifisoul

I have had my suunto t3c hrm for a few years and recently it randomly gives me a way way off calorie burn. Most of the time its pretty accurate with online heart rate calculators. I frequently check the monitor to make sure im staying within range of 160-175bpm and today for example, my average hr was 165bpm for 45 minutes. It calculated 533 calories burned , which is way off. For my age,height,weight it should have calculated around 750 calories. Now this doesnt happen all the time, and i make sure i dont change any personal settings unless my age or weight changes, but i keep getting these way off calculations every once and awhile. I also changed the batterys a few weeks ago when i noticed this happening again, but its still doing it, and i want to know why. Im wondering if theres some other reason besides the thing needing repair?

erickirb

actually for 45 min the 533 sounds much more reasonable vs. the 750. about 12cals/min vs 16.67cal/min. I can see if you are 230+lbs the 16 cals/min, but if you are much less than that the 533 sounds about right, may even be high, depending on your weight

cmriverside

Maybe you need to replace the chest transmitter. They go after a while.

nytrifisoul

actually for 45 min the 533 sounds much more reasonable vs. the 750. about 12cals/min vs 16.67cal/min. I can see if you are 230+lbs the 16 cals/min, but if you are much less than that the 533 sounds about right, may even be high, depending on your weight

You did read the part about keeping heart rate between 160-175 bpm? This is constant, no breaks, if it starts to drop i pick up the pace. There is no way in hell that intense of a cardio workout would only burn 533 or less.

Mr_Knight

actually for 45 min the 533 sounds much more reasonable vs. the 750. about 12cals/min vs 16.67cal/min. I can see if you are 230+lbs the 16 cals/min, but if you are much less than that the 533 sounds about right, may even be high, depending on your weight

You did read the part about keeping heart rate between 160-175 bpm? This is constant, no breaks, if it starts to drop i pick up the pace. There is no way in hell that intense of a cardio workout would only burn 533 or less.

Sorry, the person you are responding to is most likely correct. Especially if this is an interval-y type workout (Insanity and what not), HRMs notoriously over-estimated calorie burns.

Heart rate and calorie burn only correlate well under very specific conditions.

qtgonewild

mine is the ft7 and it LOVES to give me the check heart transmitter message EVERY time during my workout. frustrates the shhhhhhhh. out of me and i'm trying to figure out what the problem can be. If anyopne knows PLEASE HELP. thanks. and sorry, not trying to hijack your post. but if yours is doing that too, during your workout, and you are not noticing, obviously your calories will be off.

nytrifisoul

Maybe you need to replace the chest transmitter. They go after a while.

I have considered this. I have been wanting to buy the DUAL module transmitter/chest strap that works with my treadmill aswell as my hrm watch. I have the ANT module that came standard with the watch.

erickirb

actually for 45 min the 533 sounds much more reasonable vs. the 750. about 12cals/min vs 16.67cal/min. I can see if you are 230+lbs the 16 cals/min, but if you are much less than that the 533 sounds about right, may even be high, depending on your weight

You did read the part about keeping heart rate between 160-175 bpm? This is constant, no breaks, if it starts to drop i pick up the pace. There is no way in hell that intense of a cardio workout would only burn 533 or less.

I did, and intense workouts tend to burn 10-15 calories/minute depending on a bunch of factors, rarely do you see burns (that are accurate) in the 15+/min amount for any length of duration.

nytrifisoul

actually for 45 min the 533 sounds much more reasonable vs. the 750. about 12cals/min vs 16.67cal/min. I can see if you are 230+lbs the 16 cals/min, but if you are much less than that the 533 sounds about right, may even be high, depending on your weight

You did read the part about keeping heart rate between 160-175 bpm? This is constant, no breaks, if it starts to drop i pick up the pace. There is no way in hell that intense of a cardio workout would only burn 533 or less.

Sorry, the person you are responding to is most likely correct. Especially if this is an interval-y type workout (Insanity and what not), HRMs notoriously over-estimated calorie burns.

Heart rate and calorie burn only correlate well under very specific conditions.

This is not interval. This is 7/mph treadmill running with 1% or higher incline. If the rate starts to drop i pick up pace or add hand weights, or swing arms to keep rate elevated. Again, 533 is way low for extreme cardio, and as i said, this is random, I get accurate calculations most of the time with the same workout/time.

Firekeeper66

mine is the ft7 and it LOVES to give me the check heart transmitter message EVERY time during my workout. frustrates the shhhhhhhh. out of me and i'm trying to figure out what the problem can be. If anyopne knows PLEASE HELP. thanks. and sorry, not trying to hijack your post. but if yours is doing that too, during your workout, and you are not noticing, obviously your calories will be off.

I have the Polar FT60 and I get the SAME DAMN THING! Annoying is an understatement! (I still love it though)

erickirb

actually for 45 min the 533 sounds much more reasonable vs. the 750. about 12cals/min vs 16.67cal/min. I can see if you are 230+lbs the 16 cals/min, but if you are much less than that the 533 sounds about right, may even be high, depending on your weight

You did read the part about keeping heart rate between 160-175 bpm? This is constant, no breaks, if it starts to drop i pick up the pace. There is no way in hell that intense of a cardio workout would only burn 533 or less.

Sorry, the person you are responding to is most likely correct. Especially if this is an interval-y type workout (Insanity and what not), HRMs notoriously over-estimated calorie burns.

Heart rate and calorie burn only correlate well under very specific conditions.

This is not interval. This is 7/mph treadmill running with 1% or higher incline. If the rate starts to drop i pick up pace or add hand weights, or swing arms to keep rate elevated. Again, 533 is way low for extreme cardio, and as i said, this is random, I get accurate calculations most of the time with the same workout/time.

7 mph is def not extreme, though isn't slow either... How many calories does the treadmill say you burn?

BrianSharpe

actually for 45 min the 533 sounds much more reasonable vs. the 750. about 12cals/min vs 16.67cal/min. I can see if you are 230+lbs the 16 cals/min, but if you are much less than that the 533 sounds about right, may even be high, depending on your weight

You did read the part about keeping heart rate between 160-175 bpm? This is constant, no breaks, if it starts to drop i pick up the pace. There is no way in hell that intense of a cardio workout would only burn 533 or less.

There is not a linear relationship between heart rate and caloric expenditure. At 7mph for 45 minutes you would have traveled 5.25 miles. If you multiply .63 x your weight x 5.25 you would have a reasonable estimate of net caloric expenditure (ie calories expended directly attributable to the exercise) (source Runners World) Adding hand weights and/or swinging your arms doesn't make a huge difference in terms of calories. (Running 7mph is a good pace but hardly "extreme cardio")

nytrifisoul

actually for 45 min the 533 sounds much more reasonable vs. the 750. about 12cals/min vs 16.67cal/min. I can see if you are 230+lbs the 16 cals/min, but if you are much less than that the 533 sounds about right, may even be high, depending on your weight

You did read the part about keeping heart rate between 160-175 bpm? This is constant, no breaks, if it starts to drop i pick up the pace. There is no way in hell that intense of a cardio workout would only burn 533 or less.

Sorry, the person you are responding to is most likely correct. Especially if this is an interval-y type workout (Insanity and what not), HRMs notoriously over-estimated calorie burns.

Heart rate and calorie burn only correlate well under very specific conditions.

This is not interval. This is 7/mph treadmill running with 1% or higher incline. If the rate starts to drop i pick up pace or add hand weights, or swing arms to keep rate elevated. Again, 533 is way low for extreme cardio, and as i said, this is random, I get accurate calculations most of the time with the same workout/time.

7 mph is def not extreme... How many calories does the treadmill say you burn?

It maxes out at 999.I usually max it out. But i lost its chest strap, hence wanting to buy the DUAL module for my suunto.

I know the treadmill estimates high, alot higher then my hrm. I havent used the treamill calorie estimate in awhile. I actually cover it so i dont look at the damn thing.

nytrifisoul

actually for 45 min the 533 sounds much more reasonable vs. the 750. about 12cals/min vs 16.67cal/min. I can see if you are 230+lbs the 16 cals/min, but if you are much less than that the 533 sounds about right, may even be high, depending on your weight

You did read the part about keeping heart rate between 160-175 bpm? This is constant, no breaks, if it starts to drop i pick up the pace. There is no way in hell that intense of a cardio workout would only burn 533 or less.

There is not a linear relationship between heart rate and caloric expenditure. At 7mph for 45 minutes you would have traveled 5.25 miles. If you multiply .63 x your weight x 5.25 you would have a reasonable estimate of net caloric expenditure (ie calories expended directly attributable to the exercise) (source Runners World) Adding hand weights and/or swinging your arms doesn't make a huge difference in terms of calories. (Running 7mph is a good pace but hardly "extreme cardio")

I say extreme because simply going 7/mph doesnt push me anymore but going faster hurts my knees, so i added 10/lb hand weights to elevate my heart rate and intensify the workout. I also wear a 20/lb weight vest when im not using the hand weights, sometimes use both.

Mr_Knight

This is not interval. This is 7/mph treadmill running with 1% or higher incline.

Then you don't need an HRM at all:

Net burn -> 0.63 * distance in miles * body weight in pounds (plus body vest etc)

nytrifisoul

This is not interval. This is 7/mph treadmill running with 1% or higher incline.

Then you don't need an HRM at all:

Net burn -> 0.63 * distance in miles * body weight in pounds

Probably not, but i use it so i can push myself harder and it helps me make sure i keep pushing harder.

dawlschic007

mine is the ft7 and it LOVES to give me the check heart transmitter message EVERY time during my workout. frustrates the shhhhhhhh. out of me and i'm trying to figure out what the problem can be. If anyopne knows PLEASE HELP. thanks. and sorry, not trying to hijack your post. but if yours is doing that too, during your workout, and you are not noticing, obviously your calories will be off.

Mine was doing that for awhile too. You most likely need to replace the batteries in the transmitter. Also, you may need to wash the sensors on the chest strap by soaking the whole strap in water for a while and then let it dry out.

Mr_Knight

This is not interval. This is 7/mph treadmill running with 1% or higher incline.

Then you don't need an HRM at all:

Net burn -> 0.63 * distance in miles * body weight in pounds

Probably not, but i use it so i can push myself harder and it helps me make sure i keep pushing harder.

So when you do that, what number do you get? Does it agree with any of the HRM readings?

nytrifisoul

These are not the responces i was expecting, Lets skip the fact that many think my personal estimates are high and focus on the fact that most of the time it estimates what i personally believe is accurate, aswell as most online based heart rate calculators, so why is it estimating in your opinions high most of the time, and randomly estimating what you believe is more accurate?

Is it most likely the chest strap module going bad?

dawlschic007

These are not the responces i was expecting, Lets skip the fact that many think my personal estimates are high and focus on the fact that most of the time it estimates what i personally believe is accurate, aswell as most online based heart rate calculators, so why is it estimating in your opinions high most of the time, and randomly estimating what you believe is more accurate?

Is it most likely the chest strap module going bad?

You can try replacing the battery in it and see if that helps, but honestly I think the numbers are pretty accurate. You can also try a different model type and see what the outcome is for that.

nytrifisoul

This is not interval. This is 7/mph treadmill running with 1% or higher incline.

Then you don't need an HRM at all:

Net burn -> 0.63 * distance in miles * body weight in pounds

Probably not, but i use it so i can push myself harder and it helps me make sure i keep pushing harder.

So when you do that, what number do you get? Does it agree with any of the HRM readings?

math isnt my strong suit. I leave that to the hrm and online calculators based on the hrm readings. And yes most of the time i monitor the hr and also keep track of the hrm's calculated average, its spot on with every online calculator.