How are people burning such high calories

Just wanted to chime in with a bit of clarification here. Firstly, HRM's are not terribly accurate to begin with (especially the lower end models like Polar FT7). Models that take into account resting HR and VO2 max are a little better. Most folks do not accuratley know what their max HR is and/or not capable of testing it so that further dilutes the accuracy. Most importantly, HRM's are designed to estimate caloire burns for steady state aerobic activities like running, so using them for thinks like kick boxing, circuit training, or High intensity activities where many breaks are taken will not be as accurate. They are next to useless for weight lifting calorie numbers.

With all that being said, let's take about the "fat-burning" zone in an over simplified explanation. At all times during training, your body is burning both fat and carbs for energy. Your training instenisty will determine the mix being used. What the HR monitor fat burning zone is trying to tell you is the point at which your body begins to go into oxygen debt because you are excersing harder than your current fitness is capable of keeping up with. If all you care about is calorie burns, then training at this higher intsensity for short intervals is fine. Note of warning; if you don't take sufficient breaks and regularly workout at this high threshold without recovering, you are risking metabolic damage and overtraining. However, if you care about improving your overall aerboic fitness, you need to establish your base by doing a lot of easier training at an intensity at which you could still carry on a conversation.

To all the people who are telling the OP that her question is “irrelevant”…

How can you say that? That is a perfectly legit question. She is obviously trying to learn something about her HRM, reasonable expectations for a calorie burn, etc.

Whatever happened to the idea that the only useless question is the one that was never asked?

I will throw in some of my data for variation based on weight and fitness level--two runs, 4 years apart:

February 2009--ran (had to walk some) 7.0 miles, burned 1216 calories. Weight: 192. HR: ave. 176, max 181

February 2013--ran 7.6 miles (no walking), burned 690 calories. Weight: 163. HR: ave. 143, max 157

So I went nearly 10% further a few days ago but burned 526 fewer calories than I did when I was heavier and in worse shape. That's not in an hour, but I think it's a good illustration of different calorie burn.

Unless you A) set your HRM with your actual VO2max and HR max at the start, and then adjusted your HRM settings to reflect your higher VO2 max after training increases, then you are not comparing apples to apples. Your initial calorie reading were an overestimate when you started and they are an underestimate now.

Calories burned = body weight x intensity.

That's it.

Burning high calorie numbers is simple math---it just requires that someone have the right combination of weight and fitness.

220 lb person runs 6 miles in 1 hour = 1000 calories.

176 lb person runs 7.5 miles in 1 hour = 1000 calories

150 lb person: needs to run 9+ miles in 1 hour to burn 1000 calories.

Walking 4.0 mph: to burn 1000 calories in 1 hour you need to weigh ~ 500 lbs.

I usually burn less than 1 cal per minute during intense exercise, but I know I used to burn more than 1 cal per minute when I weighed more. Also, I don't let my HRM tell me how intensely I should be exercising. I use my common sense for that. Where are you getting your HR recommendations? My HR hits the 180s during high intensity intervals, and sits in the 160s during steady state cardio. Of course age, weight, gender, etc will affect what your HR "should" be.

You must mean 10 cal per minute during intense exercise don't you? You burn very approximately 1 cal/min just sitting there staring at the monitor and reading this forum.

it's very unlikely they are burning 1000 calories per hour.

I can (and do) burn a 1,000 in an hour. Here's the trick be pretty heavy and pretty fast.

I'm ~ 180 lbs and burn ~ 130 per mile. 8 miles @ 7:30 pace = 1,000+ calories.

Just this morning I ran 7 miles @ 7:32 pace, so that was 900+ in 52 minutes (would have done an hour, but I got a late start and had to take the kids to school).

I'm not sure where you got that but I'm pretty sure my Polar is a 7 (if not then 6) and it does indeed have settings for Vo2Max and resting HR.

Along, a "low end" brand would not be Pilar, the highest rater HRM's available and cost $150-$300. My irst HRM had almost no settings and cost a whopping $35 (also said I burned nearly twice what my polar reports).

Just wanted to chime in with a bit of clarification here. Firstly, HRM's are not terribly accurate to begin with (especially the lower end models like Polar FT7). Models that take into account resting HR and VO2 max are a little better. Most folks do not accuratley know what their max HR is and/or not capable of testing it so that further dilutes the accuracy. Most importantly, HRM's are designed to estimate caloire burns for steady state aerobic activities like running, so using them for thinks like kick boxing, circuit training, or High intensity activities where many breaks are taken will not be as accurate. They are next to useless for weight lifting calorie numbers.

With all that being said, let's take about the "fat-burning" zone in an over simplified explanation. At all times during training, your body is burning both fat and carbs for energy. Your training instenisty will determine the mix being used. What the HR monitor fat burning zone is trying to tell you is the point at which your body begins to go into oxygen debt because you are excersing harder than your current fitness is capable of keeping up with. If all you care about is calorie burns, then training at this higher intsensity for short intervals is fine. Note of warning; if you don't take sufficient breaks and regularly workout at this high threshold without recovering, you are risking metabolic damage and overtraining. However, if you care about improving your overall aerboic fitness, you need to establish your base by doing a lot of easier training at an intensity at which you could still carry on a conversation.

This! Agreed..

When I started back in August I would burn about 1200cals cycling to and from work, now 5stone lighter I'm lucky if I burn 600cals. That's about an hour

Well just got back from a walk with my HRM was out for 2 hours 15 min and used 1750 cal my Avg heart rate was 84 % and my Max heart rate was 97 %

wouldn't that be a run then?