Calorie counter -- how accurate? Based on what studies?

[doninaustin]

Does anybody know what kind of studies support the calories burned calculations? What body type is used? What would be the correction factor for a body type that deviates from the standard used for the ergometer's calculations? Just trying to get a feeling for whether or not they have any meaning at all other than strictly relative.

Don

[jamesg]

The C2 readout is the sum of the work input to the handle x 4 x the W/Cal conversion factor, plus a free 300/hour for sitting on the machine and moving the slide, breathing etc.

My guess is accuracy is OK (say +/-10%) if you work at 1000 kCal/h readout, but not at 500kCal/h.

If you want an accurate value, weigh yourself before and after, and multiply the kg diff plus any drinks x 500. If you sum the values over a number of days, this can be very accurate, because balance errors will tend to cancel, but you may want to look at the steam tables to get a more accurate value than 500. Or just note the litres sweated.

[c2jonw]

We use a baseline of an average 175 pound person for the calorie calculation and have both an on-line weight adjustment calorie calculator at http://www.concept2.com/us/interactive/ ... alorie.asp and we offer a cool slide chart which does the same conversion and also converts your scores to METS.
That said, even with the weight adjustment, the calories that an individual actually burns to achieve a score on the erg will vary due to differences in efficiency. C2JonW

[iain]

The 300Cal/hr added to cover calories used going up and down the slide and normal metabolic uses won't just vary with weight. As the metabolic rate of a 75kg man (the standard) is around 100/hr. the 200 is presumably for going up and down the slide. As well as general efficiency (length of stroke etc.) I believe the calories used is proportional to cube of rating. Some of this may be within the 4 x multiplier of "useful work" (as rating generally increases with pace), but I would expect that this overstates calories used at low ratings and understates for high ratings. In addition, this doesn't include calories burned after the workout repairing the body and so may significantly understate calories used on high intensity workouts.

- Iain

[q445187]

Where can I find that calculator that takes watts to mets?

[Citroen]

Where can I find that calculator that takes watts to mets?

I found this on a cycling forum

http://en.wikipedia.org/wiki/Metabolic_equivalent
They give a MET as 1 kcal / kg / hr

It basically the rate of work done by your body, normalized by your weight.
For example, if you perform 14 MET's and weigh 160 lbs (72.6 kg), you burn:
14 kcal / kg / hr * 72.6 kg = 1016 kcal / hr
This is the rate of calories burned.

Assuming a 24% efficiency (only 24% goes into the bike, I've seen this used many places, including here: http://www.braydenwm.com/calburn.htm
1016 *0.24 = 254.0117 kcal/hr put into the drive train

Convert kcal/hr to Watts to get an estimate of your power:
254.0117 kcal/hr * 4186.795 J/kcal / 3600 sec /hr = 284.6 (J/s or Watts).

[q445187]

Thank you for responding.

That doesn't do what I need though. I need to take the results from the c2, the avg watts, and get a MET value.

I have a business that has access to genetic testing (for less than $150) to determine, based on your genes, what kind of exercise (based on METS) and the percentages of calories from fat, carb, and protein that YOUR genes need to facilitate your goals.

I was hoping for a simple calculator to take watts to mets and maybe one for treadmill results also.

Jeff

[Citroen]

I was hoping for a simple calculator to take watts to mets and maybe one for treadmill results also.

It's not that simple since it's based on your BMR value.

[Bob S.]

I was hoping for a simple calculator to take watts to mets and maybe one for treadmill results also.

Jeff

Try this:

http://ptresources.com/forms/free/p_watts_mets.htm

I doubt if it is any good, but it is simple enough.

Bob S.

[macroth]

I was hoping for a simple calculator to take watts to mets and maybe one for treadmill results also.

Jeff

Try this:

http://ptresources.com/forms/free/p_watts_mets.htm

I doubt if it is any good, but it is simple enough.

Bob S.

I think it will be perfect for its intended use.

[q445187]

What do you mean "doubt if it is any good? it looks like what I need. Are you saying it is inaccurate? I am not an Olympic athlete by the way, just a normal person...

[Bob S.]

What do you mean "doubt if it is any good? it looks like what I need. Are you saying it is inaccurate? I am not an Olympic athlete by the way, just a normal person...

I just don't think that weight alone is sufficient to provide the BMR, which is needed for the met calculation.

Bob S.