OruxMaps v. 4.8.11beta calories

Today I tried the Calories indicator of the new beta version.
As descibed it works only in connection with a heartrate sensor.
On a bike ride of about 43 km it showd 2100 kcal.
For the same data mapmytracks calculated about 850 kcal.
It would be interesting to know the calculation behind the results.
I suppose that for mapmytracks it is only distance and time.
Is the heart rate a factor in the calculation of oruxmaps?
Anyway - important is only the result in comparison to a ride before
or later.
Fortunately the system do not know how many pieces of cake I had in
the break.
Uli
p.s. sorry I don't know how to upload a screenshot

Uli wrote:Today I tried the Calories indicator of the new beta version.
As descibed it works only in connection with a heartrate sensor.
On a bike ride of about 43 km it showd 2100 kcal.
For the same data mapmytracks calculated about 850 kcal.
It would be interesting to know the calculation behind the results.
I suppose that for mapmytracks it is only distance and time.
Is the heart rate a factor in the calculation of oruxmaps?
Anyway - important is only the result in comparison to a ride before
or later.
Fortunately the system do not know how many pieces of cake I had in
the break.
Uli
p.s. sorry I don't know how to upload a screenshot

Hi, Uli;

Thanks for the feedback.

OruxMaps uses this formula-->http://www.shapesense.com/fitness-exercise/calculators/

There you can find some calculators.

And you can check (using non heart rate calculator) that it is really difficult to calculate the true value.

orux

Thank you for your fast reply and the url
which is quite useful.
Now I know how you calculate calories.
I did it step by step (age and average heart rate) and
got the same result Oruxmaps calculted.

Uli

Oruxmaps - the best ever outdoor navi program

A few questions and suggestions regarding the calories computation (which is indeed a great addition to Oruxmaps):

1- I was wondering if the same formula is used regardless of the average heart rate because it seems the formulas in "http://www.shapesense.com/fitness-exercise/calculators/heart-rate-based-calorie-burn-calculator.aspx" only apply to average BPM between 64% and 89% of maximum heart rate.
2- Are the calories computed only as a global average or are they computed for each interval in a workout? (wondering if the latter would be more accurate) [Edit: on second thought I realize the computation for each interval may not make sense unless we define larger interval that contain somewhat consistent heart rates]
3- Would it make sense to start the calories calculation only when we start recording (GPS or HRM) and stop it when we stop the recording? (as of now it seems the calories count start as soon as we connect a HRM and don't stop until we disconnect it, I am also not sure how/when it is reset to zero)
4- How can we access the calories count for a given (saved) exercise? It does not show in the statistics page which would be a good place. What would also be nice is to log this in the GPX (like all the other infos such as altitude gain, moving time etc.).

Keep up the good work. Oruxmaps is an awesome application and you are doing a tremendous job adding these new functionality.

Uje

ujecrh wrote:A few questions and suggestions regarding the calories computation (which is indeed a great addition to Oruxmaps):

1- I was wondering if the same formula is used regardless of the average heart rate because it seems the formulas in "http://www.shapesense.com/fitness-exercise/calculators/heart-rate-based-calorie-burn-calculator.aspx" only apply to average BPM between 64% and 89% of maximum heart rate.
2- Are the calories computed only as a global average or are they computed for each interval in a workout? (wondering if the latter would be more accurate) [Edit: on second thought I realize the computation for each interval may not make sense unless we define larger interval that contain somewhat consistent heart rates]
3- Would it make sense to start the calories calculation only when we start recording (GPS or HRM) and stop it when we stop the recording? (as of now it seems the calories count start as soon as we connect a HRM and don't stop until we disconnect it, I am also not sure how/when it is reset to zero)
4- How can we access the calories count for a given (saved) exercise? It does not show in the statistics page which would be a good place. What would also be nice is to log this in the GPX (like all the other infos such as altitude gain, moving time etc.).

Keep up the good work. Oruxmaps is an awesome application and you are doing a tremendous job adding these new functionality.

Uje

Hi, Uje;

Please, test last beta--> www.oruxmaps.com/cs

About calories calculators, remember it is a very bad value which is calculated using this type of formulas. You can check this by trying different methods of calculation.

I will try to improve the data offered, but keep in mind that a track can be composed of several segments, and heart rate monitor data stored may not match the length of all the segments.

At the moment it is best to create a track for work, and start / stop recording the track with the heart rate monitor.

orux

Great, I see you added the HRM and calories data to the gpx export. Note that after re-exporting my last track the calories count in the export was almost half of the count oruxmap initially indicated when finished that track. Also, when I load any previous track and the HRM is already started I see the calories count in the daskboard jumping to over 12000 so there may be some problem there.

Anyway, I will try all this tonight with a new track created directly from this last beta and let you know how it works.

Cheers,
Uje

Thanks, it works like a charm. Calories got computed on this evening' outing and exported properly into the gpx.

I would not worry too much about the accuracy of the numbers as I am not sure there is a better way to calculate calories expenditure anyway. The advantage of the HRM method compared to a MET-based formula for example is that it is completely independent from the kind of exercise or the duration/distance. Therefore, accurate or not, it provides a mean to compare the efforts between various exercises (say walk vs run vs bike etc.).

One more suggestion/question. I wonder if you save all the parameters used for calories calculation in the Oruxmaps database for a given exercise (things like weight, age etc.). It may be necessary (and even adding this to the gpx exports stats) so that if someone loads an old track, the computed values (like calories) are still based on the old weight/age. Just food for thoughts.

Anyway, thanks again, I understand this is just a first try at adding this kind of features to Oruxmaps but it is already pretty useful.

Uje

Where in the gpx-file are the calories stored?
Can you give me a hint?
Sorry - my eyes are not very good.
Uli

Uli wrote:Where in the gpx-file are the calories stored?
Can you give me a hint?
Sorry - my eyes are not very good.
Uli

Hi, Uli;

Certainly it is not for human eyes:

<desc><h1>OruxMaps</h1><br /><hr align="center" width="480" style="height: 2px; width: 517px"/><h2>Nombre: </h2><br /><p>Hora Inicio: 03/23/2012 17:30</p><p>Hora Fin: 03/23/2012 17:37</p><p>Distancia recorrida: 0,5 km (00:06)</p><p>Tiempo en movimiento: 00:05</p><p>Velocidad media: 4,5 km/h</p><p>Vel. en Mov.: 5,8 km/h</p><p>Velocidad Máxima: 9,2 km/h</p><p>Altura Mínima: 947 m</p><p>Altura Máxima: 951 m</p><p>Ganancia Altitud: 0 m</p><p>Pérdida Altitud: -4 m</p><p>Tiempo Ascenso: 00:00</p><p>Tiempo Descenso: 00:03</p><p>Min. Pulso: 55</p><p>Max. Pulso: 113</p><p>Med. Pulso: 88</p><p>Calculadora Calorias: 0</p><hr align="center" width="480" style="height: 2px; width: 517px"/></desc>


Inside the desc tag of the track.

orux

If I'm not the only one who is interested in calories:
Is there a way to get the value into the statitic?
E.g. shifting Distance to the left and inserting Calories to the right?
At present time I make a screenshot of the map screen (showing the calories value), short before the
end of the tour. So I get the calory value stored.
Uli

Sorry to bother you again.
In the exported statistic the values for MIN.HRM, Avg.HRM and Max.HRM
are missing.
But that is just a little flaw and most users will not notice it.
Have a nice weekend.
Uli

Uli wrote:Sorry to bother you again.
In the exported statistic the values for MIN.HRM, Avg.HRM and Max.HRM
are missing.
But that is just a little flaw and most users will not notice it.
Have a nice weekend.
Uli

Hi, Uli;

Try with last beta-->www.oruxmaps.com/cs

--added calories to statistics view,

--should find HRM info in the exported statistics.

orux

You are too fast for me.
Great! The Value for calories is shown now in
the statistics screen.
I can store that now and see how it varies from day to day.
Haven't seen the values in the exported statistic but will give it
a try tomorrow morning.
Thank you.
Uli

I couldn't wait till tomorrow and first I loaded the old file.
But now it is right and shows all values inclueding calories.
Thank you very much.
Uli



Startzeit: 03/22/2012 08:57
Zielzeit: 03/22/2012 10:25
Distanz: 23,1 km (01:28)
Bewegungszeit: 01:26
Durchschnitts-Geschw.: 15,7 km/h
Netto Geschwindigkeit: 16,1 km/h
Max. Geschwindigkeit: 28,8 km/h
Minimale Höhe: 21 m
Maximale Höhe: 65 m
Steig-Geschw.: 403,5 m/h
Sink-Geschw.: -344,6 m/h
Aufstieg: 150 m
Abstieg: -142 m
Steigzeit: 00:22
Sinkzeit: 00:24
Min. HRM: 104
Max. HRM: 152
Avg. HRM: 131
Calories: 1148

I second that. Just tried the latest beta today and it is great. Thanks!
Uje