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WONGERCHI's Photo WONGERCHI Posts: 3,889
10/14/09 1:18 P

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Jim:
Interesting stuff about SP cal calculator - it always felt high to me but I stopped using it a while back... Didn't think to pop in the #s.

Good question about efficiency. I'm slightly confused but yeah, all things being equal, if you rode 30k in an hour one day and then the next time you rode 35k in an hour you would be putting out more power and burning more Cals. However, if you rode 30k both times, you'd be doing the SAME amount of work, only your ride would take you 51 mins @ 35kph as opposed to 60 mins @ 30kph.

Watts is a function of power or speed. So I can increase my power output by either increasing gear (force, simplistically) or speed (cadence, simplistically). So I can go from, say 200W to 250W in one of 2 ways - spin a smaller gear faster, or go to a bigger gear and hold the cadence. Cyclists who prefer to spin will do the former. Those that like to mash (i.e. me) will do the latter.

In God we trust, all others bring data.
- W. Edwards Demings

If God invented marathons to keep people from doing anything more stupid, the triathlon must have taken Him completely by surprise.
-P.Z. Pearce

Specificity, specificity, specificity.
-Andy Coggan

The plural of "anecdote" is not "data".
- Frank Kotsonis


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JHOLLNAGEL Posts: 1,768
10/14/09 11:33 A

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I know I'm late on this but boy did i learn a lot.

This is what I was able to get out of the thread: Power tap meter would be the best measurement if you could afford it.

The next best would be "Stinky Diaper's site or Wongerchi's All around rough estime of 40 cals per mile (I'll explain later)

Next would be the Garmins if you fudge your weight accordingly

The worst is SP

Now on to the numbers: Stinky indicated that on Sp he burned 3,544 calories and on his web site he burned 2,105 calories. A huge difference and roughly a 41% difference. Now if the site is relatively accurate and I have not been there to see how easy it is to key in the information .... but I took Stinky's mileage of what he did 50.1 which is what he used as his example of calories burned you come up with 2,004 calories burned which equates to about a 5% difference. Not a bad estimate.

So if you use 40 cals burned per mile cycled it would be a better guesstimator than SP. Which I think I will start using until i can afford a PT for the bike.

As far as efficiency goes I know it was mentioned that if you rode a route earlier and now it takes less time than before you have improved efficiency but aren't you also using more force and thus pushing more watts in this case as was mentioned? If you are in the same gear you are spinning at a faster rate but I would think that you are really pushing a bigger gear which will require greater force to this thus increasing the watts per hour or per ride?

Did I miss this whole discussion or am I on the right track???

Jim

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KJNE8O's Photo KJNE8O SparkPoints: (190,634)
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10/9/09 4:56 P

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OH! You're ONE of THOSE! Yup!

I work in IT as a Business Analyst and I am always working the techies so I understand. I've seen it here on SP where I start a thread about a question I have and then people are posting comments about something totally unrelated, like their dog!

At least this conversation stayed on the general topic of calories.

:)

Kris

If you focus on results, you will never change. If you focus on change, you will get results. Jack Dixon

If we all did the things we are capabale of doing we would literally astound ourselves.
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SWEETCYCLINHAMS's Photo SWEETCYCLINHAMS Posts: 1,247
10/9/09 4:51 P

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Hey, Guys, don't get me wrong. My precious feelings aren't hurt or anything like that.

I guess it's the mindset I have. I am IT guy (oh, jeez! One of THOSE! HA-HA-HA-HA-HA!) and I have long had a pet peeve about forums that tend to deviate from the topic. But that's my bugaboo.

At any rate, what I had envisioned was bringing a resource that I had found to be of value to others. I can understand, and even appreciate, the added value of the contributions of the others in this forum. Dear God! I can't tell you how refreshing it is to actually find people who are not only intelligent but people who have a shared passion.

On so many forums, even some here on SP, it's so grating to read some of the obviously misinformed entries made by people. It was at a friend's recommendation that I join this team and I am so glad I did.

So, in closing, please, no one think I'm not appreciative of the intelligent contributions of all, even on this particular topic. I merely feel (felt) that the contributions would be better served under a heading that would more accurately disclose the content.

Ride safe!

Edited by: SWEETCYCLINHAMS at: 10/9/2009 (19:37)
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WONGERCHI's Photo WONGERCHI Posts: 3,889
10/9/09 4:31 P

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STINKY:
The key word really was "accurate". SCOTTCR1 then threw in the point that HRMs/Garmins aren't accurate at all but Powermeters are, Kris chipped in with the whole efficiency thing and we just took it to its logical conclusion...

Any cal calculator is bound to spark debate on here especially seeing as the whole point about Spark is to log and track cal intake and expenditure.

But you're right, the cal calculator is pretty accurate. At least according to my PowerTap.

In God we trust, all others bring data.
- W. Edwards Demings

If God invented marathons to keep people from doing anything more stupid, the triathlon must have taken Him completely by surprise.
-P.Z. Pearce

Specificity, specificity, specificity.
-Andy Coggan

The plural of "anecdote" is not "data".
- Frank Kotsonis


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SWEETCYCLINHAMS's Photo SWEETCYCLINHAMS Posts: 1,247
10/9/09 11:58 A

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To be fair, I actually said it was the most accurate calculator I've used thus far. I never said it was the most accurate one out there. That would be a relative statement and one subject to conjecture.

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WONGERCHI's Photo WONGERCHI Posts: 3,889
10/9/09 11:46 A

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STINKY:
Sorry mate, messageboard threads have a life of their own! Saying that though, I figured this thread may be headed in this direction.

You provide a link to the calculator, then you say it's "far more accurate" than any other one out there and you don't anticipate a discussion on the pros and cons of cal burn calculations?

I was going to write a post about how I thought it came up with the #s as well, but decided against it.

In God we trust, all others bring data.
- W. Edwards Demings

If God invented marathons to keep people from doing anything more stupid, the triathlon must have taken Him completely by surprise.
-P.Z. Pearce

Specificity, specificity, specificity.
-Andy Coggan

The plural of "anecdote" is not "data".
- Frank Kotsonis


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WONGERCHI's Photo WONGERCHI Posts: 3,889
10/9/09 11:41 A

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Kris:
I think you're getting your efficiencies confused. Metabolic efficiency (conversion of energy from food to generate work, e.g. pedaling a bike) is relatively constant. The other "efficiencies" e.g. biomechanical, cardiovascular etc are the ones that drastically improve with fitness.

Lets say I do a 1hr ride at 200W. My FTP (threshold power, the single biggest predictor of cycling performance) is 200W. This is a HARD ride, in terms of exertion level. I've also burned 720kJ of energy.

(Remember, 1J = 1W per second, so 200W*3600s in an hour = 720,000J = 720kJ ~= 720 kCal (or Calories)).


Then I go train smart for a couple of months, and my FTP moves up to 250W. Now an hour at 200W is relatively straightforward. I still burn the same # of cals because my work done is the same (200W in 1hr = 720kJ) but all the adaptations in the muscular and CV systems have made it that much easier to put out that much power. So you are still burning the same # of cals, it just feels easier.

If I wanted to do a an equivalent ride to the first one, it'd have to be done at 250W. Now you're burning more cals because you're doing more work (900kJ as opposed to 720kJ).

In God we trust, all others bring data.
- W. Edwards Demings

If God invented marathons to keep people from doing anything more stupid, the triathlon must have taken Him completely by surprise.
-P.Z. Pearce

Specificity, specificity, specificity.
-Andy Coggan

The plural of "anecdote" is not "data".
- Frank Kotsonis


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10/9/09 11:17 A

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Ah - I get what you're saying, however, as they way most conversations go, the end result of where the conversation takes you doesn't look like where you started.

I'll stop talking about calories then.

Kris

If you focus on results, you will never change. If you focus on change, you will get results. Jack Dixon

If we all did the things we are capabale of doing we would literally astound ourselves.
Thomas Edison


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SWEETCYCLINHAMS's Photo SWEETCYCLINHAMS Posts: 1,247
10/9/09 11:14 A

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Kris, what I meant was, I had provided a link for a resource that I found valuable, hence the title, ''Cycle Calorie Calculator'' and had thought others might find it to be both helpful and informative to have this resource; however, what we've been discussing, as valid as the information and data may be, has nothing to do with the original post or its purpose. This is analogous to posting an ad for a car that's for sale and, instead, debating what's better for the car to achieve its best efficiency and performance, Ethanol or gasoline.

From what I can tell, the vast majority of the content of this particular forum should be under another title, perhaps, ''Watts vs. Calories vs. Metabolic Efficiency''.

Edited by: SWEETCYCLINHAMS at: 10/9/2009 (11:15)
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10/9/09 11:02 A

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Stinky - I'm sorry that this isn't giving you the information that you needed or desired. Not sure what you are looking for when you say "I was hoping for more constructive and positive feedback than the obvious volley of banter that's ensued." I though we were having a very good discussion about calorie burning and the efficacy of various tools?

"don't believe that we significantly change our efficiency. 19-25% efficiency is a pretty small range." Ah yes, I read this, and I haven't done much delving into the science of it but I did note that there was a study done on Lance that showed that efficiency took a long time to improve however there are now criticisms of the way that study was done and the results of the study may not be correct.

We just don't know - the human body is very interesting and complicated and while there are good general rules there will always be exceptions to the rule.


Kris

If you focus on results, you will never change. If you focus on change, you will get results. Jack Dixon

If we all did the things we are capabale of doing we would literally astound ourselves.
Thomas Edison


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10/9/09 10:56 A

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I think you're saying the same thing that I was trying to say - I think!

"They stick to the same speed, which gives the same cal burn but it gets easier and easier as their fitness improves (my race pace when I started cycling is my recovery pace now)."

So why does it get easier and easier as your fitness improves? Aren't you more efficient? And then don't you end up burning less calories because the amount of work you have to do to go the same distance in whatever it is - running or cycling - is less?

Kris

If you focus on results, you will never change. If you focus on change, you will get results. Jack Dixon

If we all did the things we are capabale of doing we would literally astound ourselves.
Thomas Edison


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WONGERCHI's Photo WONGERCHI Posts: 3,889
10/9/09 10:30 A

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STINKY:
That's good, because there's no stats in my previous post! It's all good ol' fashioned physics and biology. So 100% of people should believe it, 100% of the time.... emoticon


Seriously though, I'm glad you started this discussion. The relationship between cal input and output is at the heart of the SP website and it's important to appreciate how variable cal calculations can be. At least on the bike we have a good way of measuring cal burn, I'm a runner too and what happens with that?

Kris:
I meant to pick up something you said too - I don't believe that we significantly change our efficiency. 19-25% efficiency is a pretty small range.

I definitely think the plateau phenomenon occurs because people overestimate cals though. They stick to the same speed, which gives the same cal burn but it gets easier and easier as their fitness improves (my race pace when I started cycling is my recovery pace now). But they don't change the speed! IMO this is not the same as changing efficiency in the strictest sense of the word.

I'd like to see the links too if you have them...

In God we trust, all others bring data.
- W. Edwards Demings

If God invented marathons to keep people from doing anything more stupid, the triathlon must have taken Him completely by surprise.
-P.Z. Pearce

Specificity, specificity, specificity.
-Andy Coggan

The plural of "anecdote" is not "data".
- Frank Kotsonis


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SWEETCYCLINHAMS's Photo SWEETCYCLINHAMS Posts: 1,247
10/9/09 10:15 A

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That's a lot to absorb, Wonger. Are you aware that only 23% of the people actually believe 57% of the statistics they read a meager 18% of the time...statistically speaking, of course.

The funny thing is, I only wanted to share a link for a great little tool I'd found that has benefited me greatly. I was hoping for more constructive and positive feedback than the obvious volley of banter that's ensued.

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WONGERCHI's Photo WONGERCHI Posts: 3,889
10/9/09 10:09 A

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All:
There appears to some bogus physiology at work here, at least according to this physiologist. Lets start from the top...

First off, cal burn estimates are just that, estimates. The trick therefore is to limit the size of that ballpark. The best way to count calories is to measure WORK done, e.g. with a Powermeter and then calculate cal burn from there.

A watt is the SI unit of POWER. One watt is defined as the rate at which work is done when an object is moved at a speed of one meter per second against a force of one newton.

A power meter on a bike (e.g. a PT) uses a network of strain gauges to measure torque (force, in Newtons) and angular velocity (speed) to, effectively, calculate power. From there, you can calculate Joules because 1J = 1W per second.

(Side note - 1J is the energy exerted by a force of one newton acting to move an object through a distance of one meter)

The conversion factor for Joules to Calories is 1cal ~ 4.21J. The CALORIE is a definition of heat - 1 calorie is is the amount of energy required to heat 1g of water 1 degree Celcius. There is a temperature dependence between cals and joules but at 20C 1cal ~ 4.2J.

So you're thinking, OK, divide J by 4.2 to get cals, right? Not so fast. This is where it gets fuzzy. The human body is between 19-25% efficient when it comes to generating power. Using 25% to simplify the math, if 250W is getting to the road (measured by the PT), I'm actually generating 1000W. The excess energy is released as heat, we've all seen this when we work out, right?

So because I'm only 25% efficient, and 1J is ~25% of a cal, then we can simply convert J to cal in a 1:1 ratio. This is THE most accurate way of calculating cal burn that I know of.

The other cal calculators (e.g. Garmin and Polar, for example) both try and guesstimate this process. What Garmin does is take into account weight, pace/speed and time (and terrain, if GPS is on) and plugs it into some sort of formula to get METs. This is a decent approach because you don't get into HR and all the caveats that are associated with it. The problem is that the Garmin formula is consistently 45% over.

From what I remember, Polar also uses these parameters but plugs in HR too (instead of pace? I can't remember). Which is good for for you only - so a 30' Z2 workout would burn less cals than a 30' Z4 workout. Great. But the problem with Polar is setting your HR zones right - the protocol that they give you is a REALLY crappy one.

Final point, I promise...

SCOTTs actually has a pretty good example of how HR cal calculations can fall down. Just as a side note though, his formula of (work = power = watts = calories) is nice, but not strictly true. Here's why:

If you're riding with Lance, and he's shooting the breeze about Michelob (or now, that crappy flavoured beer/water thing) then the assumption is that you're going the same speed. The problem is that speed on a bike is a function of W per kg. (generally, on the flats it's a slightly different variable). So to be going the same speed, I have to be putting out the same W/kg #s as Lance, say 3W/kg. Lets say Lance weighs 60kg. He's putting out 180W. I weigh 100kg. I have to put out 300W to maintain the same speed as him, so in that hour I'm riding, I am actually burning more calories than he is, based on the calculations above.

In God we trust, all others bring data.
- W. Edwards Demings

If God invented marathons to keep people from doing anything more stupid, the triathlon must have taken Him completely by surprise.
-P.Z. Pearce

Specificity, specificity, specificity.
-Andy Coggan

The plural of "anecdote" is not "data".
- Frank Kotsonis


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SWEETCYCLINHAMS's Photo SWEETCYCLINHAMS Posts: 1,247
10/9/09 8:52 A

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I concur, Kris. Though I've not read the documentation you refer to, it does go inline with the basic physiology of the human condition, so I would agree with you solely on the basis that what you say seems perfectly logical.

I also contend, regardless of what an electrical engineer or anyone else will tell you, that watts does NOT equal power. Though it is used to measure power, it is not entirely accurate. A watt, a unit of measure named after James Watt, a Scottish engineer born in the 18th Century, is a measurement of heat ONLY. With Watts work on increasing efficiency of the steam engine, this was a value of which to be constantly aware; however, aside from measuring heat, it means nothing more. Even though there is a formula for figuring watts, 1Volt x 1Amp = 1Watt, this doesn't transfer over into certain applications (home audio being a prime example) but that's another argument for another time.

Others might be interested in reading the documentation you refer to, and I wouldn't mind learning something new, so if you could provide links, that would be great.

Thanks for the insight.

Edited by: SWEETCYCLINHAMS at: 10/9/2009 (08:53)
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KJNE8O's Photo KJNE8O SparkPoints: (190,634)
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10/9/09 7:11 A

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Sorry to disagree with you here but calorie burning is more complicated than just a unit of work. I will burn more calories because my body is not accustomed to the work. As my body becomes more efficient I will not need as much energy to fuel the work and my calorie burning will go down. This is why you have to continually change up your cardio workouts, increasing duration or effort (adding hills, increasing speed) so that your muscles have to continually adjust. To stay the same will cause you to plateau because you think you are burning the same number of calories as you were before and you just aren't. I can get you scientific references if you'd like. Let me know.

Kris

If you focus on results, you will never change. If you focus on change, you will get results. Jack Dixon

If we all did the things we are capabale of doing we would literally astound ourselves.
Thomas Edison


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SCOTTCR1's Photo SCOTTCR1 Posts: 103
10/8/09 8:40 P

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I'll try it again later Stinky, it sounds good. More parameters = more accuracy. I'm a web programmer myself of a major dot-com site but still can't get the plug-ins to work on a mac. Haven't tried on Parallels yet. For those on PC, it does sound better than HRM or SP calculator so check it out.

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SWEETCYCLINHAMS's Photo SWEETCYCLINHAMS Posts: 1,247
10/8/09 8:32 P

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That's a valid point, Scott, and if you use the SP calorie counter for your rides, you'll see that they commonly overshoot the caloric guesstimation by about 400-800 calories (at least for the numbers I put in).

I recall my first ride where I broke 50.1 miles. I did it in 2:48:26 with a solid 18.0 mph average for the first 40 miles, 17.9 for the next 5 and 17.8 for the last 5. When I punched the numbers in, SP stated I'd burned 3,544 calories while the calorie calculator I've linked (below) stated I'd burned 2,105 - BIG difference.

As I've said, this calculator is far more accurate than anything else I've found I never said it was perfect (as nothing truly will be anyway). It's your choice to use or forego it but I'm sure others will appreciate the improved accuracy and benefits it offers over other calculators.

Ride safe.

Edited by: SWEETCYCLINHAMS at: 10/8/2009 (20:39)
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SCOTTCR1's Photo SCOTTCR1 Posts: 103
10/8/09 5:32 P

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Yes, Garmin's are the worst of all time. Everytime I see a new firmware update I expect to see a "New Calorie Calibration" update but never do. Anyway, most of this stuff is highly personal... the estimates may work for some but not others...

Consider, you go on a ride with Lance Armstrong for 1 hour. You have the same bikes, same aerodynamics. You might be killing yourself and out of breath at 170bpm while Lance leisurely discusses is affliction for Michelob at a mere 115bpm. If you both have the same HRM, it will state that you burned many more calories than Lance... although, you both actually did the same work (work = power = watts = calories). Aside from some efficiency differences you can see why HR is a bad indicator for many (yes, for a few lucky folks it will be accurate, but it appears that I am not a lucky one). A nice guess, but a guess nonetheless. For me, personally, I have yet to come across a calorie counter that did NOT overstate calories. The lowest I can find is the powertap which also happens to be the most accurate I've used. Relatively, using estimates is fine, but if you are the perfectionist type and really focus on calories-in vs calories-out, I would proceed with caution.

Not sure about Bodybugg, I checked the website and it wanted $200 so that was the end of that :) It's just at HR monitor correct?

Edited by: SCOTTCR1 at: 10/8/2009 (17:43)
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10/8/09 4:44 P

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OH, and with your calculations and what my HRM gave me my HRM is pretty accurate. Thanks!

Kris

If you focus on results, you will never change. If you focus on change, you will get results. Jack Dixon

If we all did the things we are capabale of doing we would literally astound ourselves.
Thomas Edison


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10/8/09 4:43 P

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Bodybugg doesn't use HR to determine your calories burned. It's based off of heat generated.

Kris

If you focus on results, you will never change. If you focus on change, you will get results. Jack Dixon

If we all did the things we are capabale of doing we would literally astound ourselves.
Thomas Edison


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WONGERCHI's Photo WONGERCHI Posts: 3,889
10/8/09 4:33 P

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Kris:
All normal caveats apply. In fact, I think Polar is the worst for cal burn because it uses HR to calc cal burn. Which is good in theory but the way it gets you to set up your HR zones is totally bogus. The Garmin gets around this problem by not using HR but the cal burn is consistently 45% over. I just adjusted my weight down and it's fine and because it doesn't use HR it scales pretty well.

Never used a bodybugg but I'd guess it overestimates too.

Seriously, the rules of thumb work. 40 cals per mile on the bike and 100 cals per mile running. Regardless of pace.

In God we trust, all others bring data.
- W. Edwards Demings

If God invented marathons to keep people from doing anything more stupid, the triathlon must have taken Him completely by surprise.
-P.Z. Pearce

Specificity, specificity, specificity.
-Andy Coggan

The plural of "anecdote" is not "data".
- Frank Kotsonis


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10/8/09 4:20 P

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Scott - I have a Timex HRM and it seems to be pretty accurate for me on calories burned. At least it seems to be. I use that to track my calories burned during any activity.

What do you make of the bodybugg?

Kris

If you focus on results, you will never change. If you focus on change, you will get results. Jack Dixon

If we all did the things we are capabale of doing we would literally astound ourselves.
Thomas Edison


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WONGERCHI's Photo WONGERCHI Posts: 3,889
10/8/09 4:15 P

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Funny you guys should mention the PowerTap. I ran the cal calculator #s on 2 totally different rides that I've done with my PT (indoor fitness test and outdoor hilly-ish tempo ride) and the cal #s came pretty damn close to the kJ # on the PT. 1kJ ~ 1Cal assuming 25% efficiency.

So, not bad, methinks. The total cal burn # for me is the more accurate one based on my ride data.


EDITED to add:
SCOTTCR1:
I'm running Firefox 3.5.2 and it's fine. My guess is it's the Mac OS - XP in Parallels would sort it I think.

I have the same issue with the cal burn on the Garmin - I dropped my weight about 45% to match Garmin cal burn with PT work. My run cal burn #s are now more in line as well!

Edited by: WONGERCHI at: 10/8/2009 (16:19)
In God we trust, all others bring data.
- W. Edwards Demings

If God invented marathons to keep people from doing anything more stupid, the triathlon must have taken Him completely by surprise.
-P.Z. Pearce

Specificity, specificity, specificity.
-Andy Coggan

The plural of "anecdote" is not "data".
- Frank Kotsonis


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SWEETCYCLINHAMS's Photo SWEETCYCLINHAMS Posts: 1,247
10/8/09 3:17 P

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Sounds like a plan.

Just for poops and giggles, I opened it in FireFox (v3.0.10) and it worked fine. I can't imagine why it's giving problems for you but I hope it does provide some good information for you...if you're able to get it working.
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Ride safe!

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SCOTTCR1's Photo SCOTTCR1 Posts: 103
10/8/09 3:14 P

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Hmmm, sounds interesting. I use Firefox which is usually better than IE in terms of compatibility issues. Maybe I'll try it later by opening Parallels Windows XP and IE.

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SWEETCYCLINHAMS's Photo SWEETCYCLINHAMS Posts: 1,247
10/8/09 3:06 P

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Yeah, the PowerTap stuff is pretty cool - a tad pricey, but pretty cool.

Odd that it wouldn't work for you, but there is a download link, bottom of the page, where you can get the app to run locally.

This actually is a very slick app. It takes into account aero or non-aero, head\tail or cross-wind, climbing, drafting, etc. Granted, nothing is perfect but it's far better than many of the others I've found that are out there.

I'd recommend downloading the locally run app and giving it a shot. It may also be a Safari issue, too. I know it works fine on IE 6 and 7.

Edited by: SWEETCYCLINHAMS at: 10/9/2009 (12:00)
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SCOTTCR1's Photo SCOTTCR1 Posts: 103
10/8/09 2:35 P

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Didn't work for me... on a high powered Java enabled MacBook Pro. Perhaps the "copyright 1997" is to blame... who knows. Anyway, I'll "weigh in" on calorie expenditure related to cycling....

Quick Physics... A calorie is a unit of work... Work is often measured in the power unit of watts. Do more work (or output more watts), burn more calories. Like a light bulb, you can burn dim for a long time or bright for a shorter time... Easy.

The problem is that here are many, many devices and "web calculators" that claim to calculate your calorie expenditure during exercise. Some, like Polar watches, try to use your HR and weight to guess the amount of work (power or watts) you are doing or outputting. They don't know what is going on with your legs and power output through the pedals... they just know your weight and heart rate. I have found that just about all of these overstate the caloric amount. Garmin is probably the worst offender I've ever seen, online calculators (including SparkPeople) is very very bad, Polar is also way overstated.

If you REALLY want to know how much power you produce during a ride, buy (or borrow a friend's) PowerTap or SRM Power Meter. These devices actually measure the power or work that you push through the pedals. Since work = calories, this is the only accurate way to determine your true expenditure.

I used to ride with a PowerTap many many years ago so I know the basic power to calorie conversion and what I can expect when I go hard, or go easy... so here is what I do...

If you own a Garmin (Edge cycling computer, or Forerunner):
Adjust your weight in your "Profile" to 65% of your current weight. For instance, I weight around 175lb and my Garmin is set at 110lbs. The calorie expenditure estimates are then relatively good (still a bit overstated I think, but much closer to actual), although still estimates. (But even after doing this conservative measure, I still get people on SP that say "4000 calories in one workout!!!" ... what they don't know is that my Garmin [and Spark People calculator] WOULD'VE stated 6500 calories if I didn't make the change. (yes, it's a long ride, 100 miles in 5 hours)

If you own a Polar HRM:
Do as above, but I can get away with saying I am 120lbs. Overstates badly if you enter your correct weight as above.

If you use online calculators:
Unless they ask your 1) Average speed, 2) elevation gain, 3) Heart Rate, 4) Wind speed and direction... then it is a total guess. Simply entering distance or distance and time is not going to produce an accurate measure of how much power you output to the pedals during the ride.

If you don't have a Polar or Garmin:
Use this basic rule of thumb:
1000 calories per hour is HAMMERING... ie you probably are in shape enough to enter a race and during this particular hour you where going as hard as you would be going in any race where you broke away from the peloton and rode like your life depended on it. I like this idea because sometimes I go "hard" but not "race hard" so I guess 750 calories per hour... if I'm lazy, 400-500 calories per hour. But all this does depend on your efficiency.

So basically that is all. You can pedal twice as hard for an hour or go for 2 hours and you burn the same calories. I recommend anyone within a "friend reach" of a PowerTap to try one out so you can see exactly how much your online-calculator/Heart Rate Monitor/Bike Computer is overstating your power.

Calories and Power and Work have only marginal relationship to speed (hills anyone?) or heart rate (fitness, efficiency, etc) which is what most simple fitness computers use.

Just my 2 euro cents.

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SWEETCYCLINHAMS's Photo SWEETCYCLINHAMS Posts: 1,247
10/8/09 1:28 P

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Several people have commented on needing an accurate calorie calculator for their rides. While SP offers a decent all-around calculator, it is far from accurate. This is one specifically for cyclists:

http://www.geocities.com/SiliconValley/V
ista/6434/CalCalcApplet.html

I think you'll find this to be far more accurate, especially taking into account several variables that are omitted on others.

NOTE: You will need to have Java installed for this to work. You can get Java, for free, from http://www.java.com/

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