BMR, Pulse Monitor & Calories...confuzzled!

Liadora11

Ok, so I bought me a watch that calculates how many calories I burn by measuring my pulse, weight and height. After using it for a couple of days it suggests that I am burning about 200 cals per hour in my regular daily activities (student so lots of sitting interspaced with lugging a 25kg rucksack about campus) and about 100 cals per hour while sleeping. That would mean that on average I am burning about 4000 cals per day.....surely that can't be right? I'm a 27 year old, 85kg, 163cm woman.
When I work out it goes up to anything between 400 and 1000 cals per hour, depending on what I do (500ish for zumba and karate, 1000 for an hour long hike).
So if I take a regular day, add to that 1 hour of hiking and an hour of karate training and I would need to eat BUCKETLOADS of food in order to make my numbers match up, and I don't. I hardly ever go over 2000 cals per day.

Is my watch playing silly buggers? Should I ignore it? Thanks in advance!

//Lia

DocMarr

Have you checked that the setting for your monitor are definitely set for someone your height, weight and age? Maybe they are set for a much bigger and heavier person? However, it may be right as you do do a lot of vigorous exercise and you are carrying quite a bit more weight than me, which makes a difference. (I'm 164 cm but weigh 67kg). I have found that if I have a sedentary day I burn 1550 calories. If I have an active day (like yesterday with zumba, weights and a run) my daily total goes up to about 2400. So as you'll burn more being bigger, you may well get to 3000 calories. You can still eat lots and lose weight when you are doing so much exercise.

BobSassafrass

Well just to add some common sense into this, are you rapidly losing weight atleast 1 pounds a day? Then yeah it's probably off, I trust MFP estimates before the HRM personally. Plus what is the point of looking for the burn for your everyday activities like sleeping? MFP already takes regular activities into account when giving you your calorie limit so you should really only use the HRM for exercise.

omma_to_3

What kind of watch did you buy? Because no, it doesn't sound right at all. If it's just a HR monitor, with the wrist watch only, it's NOT accurate. It would only take a measurement when you touch it. But since you said it monitors your sleep, that doesn't sound like what you have. Any heart rate monitor is only going to be accurate for aerobic activity with a heart rate above a certain threshold and they're not made to be worn all day.

The only things that do (in theory) measure your full daily expenditure would be something like a Body Bugg.

iWaffle

When I work out it goes up to anything between 400 and 1000 cals per hour, depending on what I do (500ish for zumba and karate, 1000 for an hour long hike).

Don't use the heart rate monitor (HRM) for anything other than stuff you do outside of your daily activities. Resting calories aren't easily recorded by a HRM so the reading will be way way off for those times.

Liadora11

Erm, I'm from Sweden and I bought the watch from Jula.

It has an a timer function, you set the clock ticking, then stop the clock and check your heart rate, then it calculates what calories you burned assuming your heart rate was constant the whole time. Yes I see the flaw sooooo.... I left it recording for 3 days and intermittantly checked the calories it offered me, then took all the readings I got to work out an average (I know I'm such a geek).

It has been set for my height, weight and age too.

I have only been using it this past week and I haven't lost anything.

I forgot to mention that I do heavy karate training 3 times a week too. Don't know if that's important.

omma_to_3

Sorry, it's not going to do what you want it to. Polar makes a good HRM that is likely available in your country but that still is only accurate for cardio workouts above a certain threshold.

Mokey41

HRM's are set with algorithms for your heart rate being elevated. They aren't made to be worn all the time and give hugely exaggerated numbers (as you've found out). Without a chest strap it will be inaccurate to start with because as you mentioned it assumes your HR has been constant for whatever period of time it's been between readings. Your HR can vary wildly within any period of time (ex: if I'm running my HR may be 155 but if I stop and walk 30 sec it will be down to 130).

Liadora11

So just use it for specific exercise sessions and ignore it the rest of the time, check!

Thanks folks

Cyclink

Your watch is way off.

How far off, you may ask?

I'm 5'9", 175 pounds, and I ride my bike at 18 to 20 mph for two hours (6 days a week) and I only burn 3000 calories per day.