Heart Rate Monitors...Calories burned accurate? Polar F11.

I recently changed my Polar F5, to a Polar F11.  I input my weight, height, age and gender and set my monitor.  I try to stay in the 142-160 bpm.  I'm pretty fit aerobically, so I push myself.

So today I did a HIIT session.  I walked at 4.2mph at 2% incline for 2 minutes and then ran at 6.8mph at 2% inclide for 1 minute.   I did this for 25 minutes and then did a cool down for 5 minutes.  Then I did 4.2 mph at 2% for another 15 minutes for a total of 45 minutes.  The heart rate monitor said I burned 746 calories!!!  WHAT?  That sounds really high!  My old one would have shown 500-550.  

AT the end the review said my average was 147 bmp at 82% of my MHR.  Does this sound right? 

 

yeah. that sounds a bit high to me.

I think that sounds right. I have an F11 too and when I do hiit, I will usually do it for about 30 mins on treadmill, although I only get up to about 5.5 mph during my sprint, for 1 minute, and stay in the 3.6-4.0 range for about 5 minutes. And mine says I will burn close to 700 at that speed. Sometimes at that speed my heart rate will get to over 95%. Yikes! But I'm out of shape and 36 years old too... :(

I'm 40!  Do you use the "ownindex" they give you  or do you turn it off?  I'm thinking the "ownindex" might not be accurate and turn it off because I had a professional do my VO2Max and it was 41.2 not 58 like my Polar F11 said. I'm definitely in the above average for fitness, but NOT elite!  I think this might be where it's calculating too high?  Then again, I did eat and walk the dog before I did the test.  I will do it again tomorrow before I move or eat and see what the test score says.

 I'm going to turn it off, do the workout again on Friday and see what the calories say then.  My old one did not have the "ownzone" and would register around 500-550 calories for that workout.

 Thanks so much for your response.  Maybe it is correct... 

i have an f11 too.  i can work as hard as i want, but can't seem to burn more than 650/hr (and that's like when i'm like sprinting away).    when i do hiit, i burn about 210/20minutes.  so to me your numbers sound really high; but i don't know if maybe you burn more calories bec your vo2max is different?  i don't know.

If you did the fitness test correctly it should be pretty accurate.  HOw long ago did you have it done by the physcian??  Mine can change by 5- 10 pts up and down on any given day I do it.  I'd say if its been over a month and you've done some good cardio workouts in the meantime your vo2 could be much higher.

I love my F11 and have used it for years and for most workouts this site and waht my HRM says I burned are well within 100 cals of each other usually with this site being more. 

HOw was your weight loss with the old monitor and the lower cal burn vs now?  I mean if you were good and sticking with the <500 of burn and losing a lb a week then I'd say your old hrm was probably pretty good.  If you start to lose slower accounting for more intake because you eat more then your new HRM may not be adjusted right for you.

I know my calorie burn for the same or similar workout within the same week can vary 100 - 300 calories alone.  Stresses in your life or even how much sleep you had the night before can effect how many calories you burn.

I did my VO2Max 6 MONTHS AGO.  So you may be right because since then my workout have been 3-5 days a week and ALL within the 143-161 BPM rate for 45-60 minutes.  I try to stay in the 80% of my MHR. Back then my VO2Max was 141.2 which is above average for my age.

Maybe those 6 months really did improve my fitness that much.  I'm here because for years I only ate 800-1000 calories a day and still weighed 155 ( I still do!)  I've been slowly upping my calories over the last 6 weeks to 1200-1300 (NO WEIGHT LOSS, but GAIN of 3 lbs. )  I'm now taking in anywhere from 1450-1700 depending on the day and trying to slowly up the calories on my workout days to 1800 in HOPES to lose 15 lbs. by June or July.  I would like to be at 138-140.  I'm 5'7".  I will see what happens this week.  I figure it will take months to fix my metabolism and that I may gain for a while till my body realized I'm not trying to starve it anymore.

Any suggestions? 

Definetely redo the vo2 test  - do it first thing in the morning before any food or caffiene I try to do mine before I even get out of bed. 

Also vary your workout intensity-- its just as important to do light workouts.  YOu didn't say how old you are but at 5'7" 155 lbs is good.  I'm 5'6" and my goal is to be 155 I am 48. 

The polar f11 has programs it suggests use that function -- its a great way to add variety to your workouts and keep the body guessing and helps keep it working more efficiently.

Because they focus on the heart rate, there are other things that may make the HR increase higher than normal.  If you were dehydrated, stressed, a little sick or fatigued.  My HR goes higher on days that I did not sleep well.