Forums >Suggestions and Feature Requests>Calories burned calculation?

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ScottChapman

It would be nice to automatically calculate this. A simple formula is weight*distance*.653. But I bet there are other ones...

Scott,
I'll add it along with the VO2 max calculation
eric

I added calories burned and VO2 Max calculations for run entries. These values are only listed when you view the run entry (as opposed to editing it). Here is the caveat. For calories burned, you need to enter a distance and weight. This will be easier once I add weight pre-population.
I looked through some of your logs to check if the numbers are realistic, and they are quite shocking for some entries. For example, jlynnbob burned over 13,000 calories on his 100 miler stint, and oce222's VO2 max for his marathon was 61.8! You guys are amazing!!!
eric

Eric,
Just noticed the calories burned stat come up when I looked at the details for a workout. Very nice! Any chance you can sum these and add it as another line on the calendar page, in the column for the weekly summary? You know: Run: x mi\n Calories: Y cal.
You're way ahead in terms of features---you've got things I haven't seen anywhere else and haven't ever thought of. Nice work!
-tm35

ScottChapman

I don't see where this shows up. I am seeing the VO2 max calculation (nice!).
I click on the workout, but I don't see it in the details.
And, I agree, it would be a useful stat to show and report on in summaries.

ScottChapman

Never mind. I see it. I guess it doesn't appear if there is missing data (like no weight specified).

I think the calories burned is great. Have you thought about taking it a step further and letting people graph calories burned by week, date, etc? Also could you add the calories burned for cycling workouts? If I run and bike the same week it would be really cool to see how many calories I burned each week.

chill182,
I need to revamp the searching/graphing code to handle more than just running. Hopefully I can get to that in 2 months. I'm tied up with another major feature right now. I want to add the calorie calculation for common workouts, but I need to find the formulas first. If you have one for biking, let me know and I'll add it.
eric

ScottChapman

Well, I found a site that has good information about calculating calories burned cycling. It is a very good read, but a bit complicated. There are some simplifying things that can be done:
http://www.cptips.com/energy.htm
Or simpler: http://www.calorielab.com/burned/

Scott,
Thanks for the link. I read through it and it was very interesting. It brought me back to the days of high school and college physics. You are certainly right to say that it is complicated because there are so many variables. Obviously, calorie calculation will always be an estimate unless you get hooked up in the lab.
I guess I'm asking where do you draw the line between asking for too much detail and not enough? Asking if you were drafting is probably too much. How about elevation changes? Would you settle for a simpler formula? I found one that uses a lookup table for the coefficient, which I can combine with the distance and time to come up with a calorie estimate. For example:
8 miles/hour = 0.0295 cal/lb/min
20 miles/hour = 0.0891 cal/lb/min
Would that be acceptable?

I would be happy with a rough estimate.

ScottChapman

I agree, I think simple rough estimation is just fine.

ok, I'll use the look up table to cycling calories.

My watch does my calorie calculation for me; not sure how accurate it is; but maybe add a field where we can either type it in manually or have it calculate.

Goals: 20:00 5K, 3:30 Marathon, Finish Marathon, 4:00 Marathon, Finish IronMan, 45:00 10K

I think you will need to add the elevation somewhere in the equation.
The best way to do it would be:
E = climb * weight * g;
where
E is the energy output in joules, climb is in meters, weight is in kg and g = 9.81
The energy expenditure is
E_in = E / efficiency.
Efficiency ranges from 0.14 to 0.27 for cycling. You could just use the 0.27 value and let users plug in their own estimates perhaps.
To convert to kcal, simply divide by 4184
a lot of my climbs are done at a pace smaller than 10km/h but at a climb rate of more than 10meters/min I personally use my HRM to estimate the calories so I could plug a value in if I needed to.

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Forums >Suggestions and Feature Requests>Calories burned calculation?