Calorie Count Algorithm

[jowwy]

And there is also plenty of calorie counting websites out there that u can put weight, speed and time into that will give a decent reading on calories burnt too.

But everything is based on averages and assumptions........and you know what they say when you assume something.

:-)

 

[amaferanga]

Thats because tdf riders are fitter, stronger and lighter than the average overweight guy on a bike trying to lose weight.

The more unfit and overweight you are the harder your body works to do certain things. Hence the higher calorific burn.

It's very simple - for cycling the calories you burn is mostly determined by your power output. So even if the fat, unfit cyclist is sweating like a pig, it's very likely their power output is significantly less than that of even an amateur racer. They might feel like they're working harder than the Pro cyclist, but in cycling it's all about the Watts you're putting out.

To give you a bit of perspective on your calories burnt figure....

1100 calories --> 306W power output --> enough power to average ~25mph on a road bike on a flat road. 306W is also a very respectable power average for a pro cyclist on a TDF stage. 306W is not a likely power output for someone averaging only 12.6mph on rolling roads in the UK.

Just because you're overweight doesn't change the fact that calories burnt comes from the energy you use to propel yourself forward and if as an average overweight cyclist you can average 306W for an hour then I suggest you give up your day job and train full time because you're blessed with a talent and a pro contract will be well within your reach.

I'm sure you won't accept this because you've looked at some websites that say otherwise, but please stop perpetuating the wildly optimistic calorie figures.

 

[lulubel]

The 705 uses distance/time to calculate calories burned, and the 800 uses your heart rate. Hence the difference.

http://www.weightlossresources.co.uk

How many calories will cycling burn?
Depending on your weight and exertion level cycling will burn off between 75-670 extra calories* in a half-hour cycle session.


30min Cycling will burn:

• Recreational, 5mph: 75-155kcal
• Moderate, 10mph: 190-415kcal
• Vigorous, 15mph: 300-670kcal

That particular website (which I use because it's very useful for keeping track of calorie consumption) underestimates my cycling calories burned by 150-200 an hour.

 

[jowwy]

The 705 uses distance/time to calculate calories burned, and the 800 uses your heart rate. Hence the difference.



That particular website (which I use because it's very useful for keeping track of calorie consumption) underestimates my cycling calories burned by 150-200 an hour.

No it doesnt LULUBEL that site and all the other sites that estimate calorie consumptions including heart rate monitors are absolutely useless because the above members said so!!!!

 

[lulubel]

No it doesnt LULUBEL that site and all the other sites that estimate calorie consumptions including heart rate monitors are absolutely useless because the above members said so!!!!

Calorie consumption is the amount of calories you consume by eating food. There's no estimate involved, unless you guess your portion sizes. If you weigh everything, you can calculate your calorie consumption accurately.

As for calories burned, that's another matter entirely. I'm not aware of any totally accurate way of calculating it (although I suppose it could be done in controlled conditions in a lab with the right equipment) because there are so many variables involved. Experience tells me that my HRM is fairly accurate for me.

 

[jowwy]

Sorry lulubel burnt is what i meant to say.

And as for heart rate monitors mine works for me too, hence the 4stone + weight loss.

 

[amaferanga]

Calorie consumption is the amount of calories you consume by eating food. There's no estimate involved, unless you guess your portion sizes. If you weigh everything, you can calculate your calorie consumption accurately.

As for calories burned, that's another matter entirely. I'm not aware of any totally accurate way of calculating it (although I suppose it could be done in controlled conditions in a lab with the right equipment) because there are so many variables involved. Experience tells me that my HRM is fairly accurate for me.

A power meter. The only unknown is your efficiency, but this doesn't vary much between individuals and for a given person it changes little if at all with changes in fitness. Certainly should be possible to compute calories burnt to within 10% for anyone.

No it doesnt LULUBEL that site and all the other sites that estimate calorie consumptions including heart rate monitors are absolutely useless because the above members said so!!!!

Just because a hundred websites repeat the same bit of information doesn't make it correct. You cannot reliably calculate calories burnt from HR. That is a fact. If it happens to work for you then you're very lucky, but stop kidding yourself into thinking you're burning 1100 calories riding at 12.6mph for an hour.

 

[lulubel]

A power meter. The only unknown is your efficiency, but this doesn't vary much between individuals and for a given person it changes little if at all with changes in fitness. Certainly should be possible to compute calories burnt to within 10% for anyone.

A power meter only records chemical energy that has been converted into kinetic (movement) energy required to move the bike. It doesn't record chemical energy that has been converted into electrical energy (within the body's nerves) or heat energy. Just 2 examples. In most kinds of energy conversion, heat is a massive "waste" of energy. Our bodies generate a lot of heat - that's why we sweat.

Your posts are as evangelistic about power meters as other people's are about heart rate monitors for calorie calculation, but you're just oversimplifying a massively complex process.

 

[amaferanga]

A power meter only records chemical energy that has been converted into kinetic (movement) energy required to move the bike. It doesn't record chemical energy that has been converted into electrical energy (within the body's nerves) or heat energy. Just 2 examples. In most kinds of energy conversion, heat is a massive "waste" of energy. Our bodies generate a lot of heat - that's why we sweat.

Your posts are as evangelistic about power meters as other people's are about heart rate monitors for calorie calculation, but you're just oversimplifying a massively complex process.

I give up. If you still believe that you can calculate calories burnt from HR then I suspect that your mind is made up and closed and that you won't even consider that the science behind that is flawed.


A power meter will be consistent for everyone with only one assumption. HR based estimates could be way out or they could be close, but you'll never really know for sure.

 

[lulubel]

I give up. If you still believe that you can calculate calories burnt from HR then I suspect that your mind is made up and closed and that you won't even consider that the science behind that is flawed.

I notice that I'm losing weight at the rate I expect with the calorie deficit I've created using the figures from my current HRM. I've used other HRMs in the past, and they haven't given me the same figures, or the same results. I also don't claim that any HRM will give accurate figures for any individual. I do claim it's better than using distance and time to guess calories, which can give wildly inaccurate figures.

A power meter will be consistent for everyone with only one assumption.

Consistent, yes. But consistently right is very different from consistently wrong.

Also, as you can see from my post above, a power meter disregards a significant amount of chemical energy use. Basing calorie input on figures from a power meter will result in the body receiving insufficient energy input and making adaptations to improve efficiency in energy use. This is an excellent result if your goal is increased performance, but a very bad result if your goal is weight loss. If you are trying to lose weight, you want your body to use energy as inefficiently as possible.

HR based estimates could be way out or they could be close, but you'll never really know for sure.

I know for sure that I'm logging the calories my HRM gives me and I'm losing weight at the rate I expect.

 

[VamP]

Your posts are as evangelistic about power meters as other people's are about heart rate monitors for calorie calculation, but you're just oversimplifying a massively complex process.

No. Unlike you amaferanga knows what he's talking about.

Still, carry on as you are, you are only kidding yourself, and not causing any harm

 

[VamP]

I know for sure that I'm logging the calories my HRM gives me and I'm losing weight at the rate I expect.

You're adding up two wrongs and coincidentally getting a right. Good for you. Now stop spreading the nonsense.

 

[Rob3rt]

I dont know how these Garmin algorithm's work, however I would expect them to only use HR as some sort of scaling factor, as given a proper minimum HR and a tested max HR it is sort of like an percieved exertion, the device percieves you to be working to a certain intensity and thus can adjust its output (of course its an indirect measure thus anything infered from this is subject to error). I would be doubtful of such a device only taking into account HR.

A power meter will give the best measure no doubt, however it still will not be truly accurate. But really, who needs super accuracy?

 

[VamP]

A power meter will give the best measure no doubt, however it still will not be truly accurate. But really, who needs super accuracy?

Totally agree. Most people will be better off by assuming 500 calories per hour of fairly intense cycling, than almost anything else. Any efficiency variations from that will be less than 10%. Well below what is actually controlable within a daily diet. And way better than letting a cock-a-hoop website con you into believing you can burn more than twice what you actually are burning.

Not a big problem if you only cycle a couple of hours a day, but if you're riding 5+ hours regularly you'll get into some serious overeating

 

[lulubel]

No. Unlike you amaferanga knows what he's talking about.

Still, carry on as you are, you are only kidding yourself, and not causing any harm

I don't doubt that amerferanga knows what he's talking about, but what he's talking about is only one very simple part of the science. Unfortunately, calculating required calorie consumption is far more complex than:

BMR + day to day activity + what my power meter says = how much I need to eat

The human body isn't a computer, and anyone who believes you can calculate its needs with a few basic equations is living in fantasy land.