Calories and Calories....

[oliglynn]

I've recently invested in a cateye v3 computer with heart rate monitor, and it gives me a calorie reading for my rides. The manual tells me this is calculated using your heart rate (my heart rates measured by the v3 seem to be accurate). The values it calculates for calories however are wildly different to those that I have been calculating on internet sites which I use to log rides.

Take for example my commute home today. 9.4 miles, at an average of 18.7mph, avg heart rate 143bpm. Flat terrain.

cateye v3: 220 calories (based on heart rate)
mapometer.com: 598 calories (based on my weight and distance)
http://www.csgnetwork.com/caloriesactburned.html: 592 calories (based on distance, speed band (16-19 mph), and my weight).


How are these values so different?! I know that the calculations measure different variables, and make different assumptions, but to have this kind of error seems crazy. I just want a rough estimate of calories burned so I can get an idea of how much I'm burning with my commuting and other rides. Which of these estimates seems the most realistic? The internet calculated ones or my Cateye's figure?

 

[Tyres23]

Yes they ate pretty out there I did 52 miles some long slogs avg of 14.4 calories burned 2750!!!! Yes if only

 

[Tyres23]

Poops 42 miles still aiming for the big 50

 

[amaferanga]

220 is too low, but then 600 is way too high for a 30min ride at that speed (unless you were climbing a mountain). If you assume 500-600 an hour riding at that speed then you probably won't be far under, but more importantly you won't be overestimating the number of calories you've burned.

 

[oliglynn]

Don't want to over-estimate, as i'm trying to lose a little weight. Just like to know roughly how much chocolate I can scoff having commuted, and still have a small calorie deficit....

 

[Moodyman]

Don't want to over-estimate, as i'm trying to lose a little weight. Just like to know roughly how much chocolate I can scoff having commuted, and still have a small calorie deficit....

I recall that after extensive tests the conclusion was that the average person riding at a decent but not lung-bursting intensity burned 35 calories per mile. This was a conservative estimate. So your 10 mile ride would equate to around 350 calories.

 

[Alun]

15 miles for 100g bar of Cadbury's.

 

[lulubel]

What data does the Cateye collect from you? My Garmin collects height, weight and "activity level", and uses that data in conjunction with heart rate to calculate calories.

I generally get around 600 cals an hour with my average heart rate in the 140s, but it fluctuates between 120s-170s due to the hills, which results in more calories burned overall. Assuming your heart rate is steadier because you're riding on the flat, your overall cals burned would be lower, but I think 440 per hour is probably a bit on the low side.

 

[oliglynn]

The cateye claims to "display the estimated calorie consumption from the start of measurement based on the heart rate." So heart rate and either distance or time. I thought the figure sounded low, and it seems to be consistently low. HRM is showing what i'd consider to be accurate data for HR.
7 mile commute this morning, 24minutes, avg 17.2mph, avg heart rate 126 = 144 calories burned. Doesn't sound right to me - doesn't even cover the 42g granola bar I had for breakfast.

 

[lulubel]

To be honest, I don't burn many cals with my heart rate in the 120s, so that one doesn't look far out to me.

 

[jowwy]

To be honest, I don't burn many cals with my heart rate in the 120s, so that one doesn't look far out to me.

i'd be saying the same - to burn sufficient calories or fat your heart rate should be up around 85% of your maximum.

the maximum being 220 - minus age = MHR

then to burn fat you need your heart rate to be in the 65% to 85% zone.


only hitting 120bpm thats just like taking a quick walk to the shops or a quickesh walk with the dog.

 

[Deleted member 1258]

Where does age fit into all these figures? whether I use the old 220 minus age calculation or max it out on a hill my max heart rate now is a lot less than it was twenty years ago, and I probably burn calories different as well. How do these take that into account

 

[amaferanga]

You can't base calorie burn on HR, hence why all these devices and websites give estimates that vary wildly. Manufacturers will claim they have the best algorithm ever for calorie estimation cos it sells their devices, but the reality is that they're all just guesses and a given device may provide a good guess for one person, but a rubbish one for another person.

Pick a number and stick with it (e.g. 500 kcal/hour) or get a power meter and calculate the energy you expend.

 

[Arsen Gere]

dave_r, your max heart rate is subjective too. 220-age is another rough guess. You can work it out though by repeated testing.

As you get older two things happen, your resting pulse rises and your max falls, double whammy to age groupers.

In my twenty's I had a resting hr in the upper 20's lower 30's and a max in the 200's now its low 40's and 164, I'm 51.

I can get my max by running hill repeats, its safer than doing this on a bike. You can use a turbo trainer too.

When you are maxed out you start to feel a tingling in your fingers, arms and scalp, your vision starts to go. It might be spotty or tunnel. Beyond that you start to keel over. I've tried it a few times. If your ticker is ok you'll survive, you can't oxygen deplete yourself to death its like strangling yourself you can't do it. Thats your true max, your body can't take anymore.
You can't repeat this two days in a row and get reliable results, it takes a couple of days to get things cleared out. In the experiments I have done, I have found alcohol improves the repeats if you do them two days in a row, I'm talking half a pint not a skin full. I don' t know exactly why, may be blood vessel dilation, carbs etc.

 

[Arsen Gere]

All these devices are inaccurate when it comes to measuring 'total callories burned'. They don't take in to account the total energy expenditure, the wind for example a big factor on a bike.

The best way for mere mortals like us to work out the energy expenditure is with a good power meter. But even then it is only for the duration of the ride.

What you have to bear in mind is to maintain a pound of muscle you need 90 cal/hour, a pound of fat 3 cal/hour.

When you train hard, intervals for example you continue to burn a large amount of calories after you stop. You can see your heart rate elevated the next day after some sessions. This is the period when a lot of fat burning takes place.

A lot of the fashions around burning fat now include HIT, high intensity interval training, not because of the fat burned during the session but the elevated metabolic levels it creates which burn a lot of calories.

I think these devices are fun and the more things you can measure AND RECORD, the better you will become.

HTH.