Such thing as burning 900 kcalories/hour?



Mike_Rides_Red

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Oct 30, 2003
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My polar S-720 saids at 194 bmp (when my max is 204) that i am burning 911 calories an hour. Also i rode 3 hours quite intensively and it said that i burned about 2000 calories. Is all this possible cause if it is i need to eat alot more calories. How many calories are you guys burning?
 
Mike_Rides_Red said:
My polar S-720 saids at 194 bmp (when my max is 204) that i am burning 911 calories an hour. Also i rode 3 hours quite intensively and it said that i burned about 2000 calories. Is all this possible cause if it is i need to eat alot more calories.

Yes, if you are riding at your max sustainable power, I.e., equal to a 40K TT, you will burn that amount or more. Racers can burn 5-6000 calories or more during major mountain stages
 
My Powertap says that I burn about 1000 kcal/hr doing my endurance rides. I ave around 280 watts at a ave HR of 145-155bpm. The amount of kcal's you burn is dependant on the energy you are using i.e watts.... Your HRM is just making a guess.


grchester said:
Yes, if you are riding at your max sustainable power, I.e., equal to a 40K TT, you will burn that amount or more. Racers can burn 5-6000 calories or more during major mountain stages
 
OKpro said:
My Powertap says that I burn about 1000 kcal/hr doing my endurance rides. I ave around 280 watts at a ave HR of 145-155bpm. The amount of kcal's you burn is dependant on the energy you are using i.e watts.... Your HRM is just making a guess.
That's exactly right. A HR monitor uses a calculation based on the linear relationship between HR and O2 kinetics. However, Polar themselves acknowledge the high degree of variablitliy in their products prediction of calories used, especially when the effort is varied (as is typical when cycling outdoors, especially over rolling terrain or when with a group). A power meter will give you a very accurate, measured (rather than predicted) amount of calories used.
How many cal/hr you are using is highly influenced by your mass as well as your intensity - the larger the cyclist, the more energy is required to move down the road, uphill or flat (but not downhill ;) ).
 
I was amazed at my output considering my weight, 5'11 145lbs. Even my coach was surprised that I was using that much energy during my "base" rides. But to each his own....





Smartt/RST said:
That's exactly right. A HR monitor uses a calculation based on the linear relationship between HR and O2 kinetics. However, Polar themselves acknowledge the high degree of variablitliy in their products prediction of calories used, especially when the effort is varied (as is typical when cycling outdoors, especially over rolling terrain or when with a group). A power meter will give you a very accurate, measured (rather than predicted) amount of calories used.
How many cal/hr you are using is highly influenced by your mass as well as your intensity - the larger the cyclist, the more energy is required to move down the road, uphill or flat (but not downhill ;) ).
 
Given that dieting is somewhat important to cycling and racing, Smartt/RST's comments got me started doing a little 'research':

According to the Power-FAQ(1) work reported from powermeters will have to be adjusted for thermodynanic efficiency(TE) to get the total metabolic work (MW): that work your body has performed to produce the net effect that the powermeter accurately reported.

The Power-FAQ states that TE can be expected to lie between 20% to 25%, from individual to individual. (2) and (3) verifies this to some extend, and also adds evidence that TE varies with intensity and pedal rate. Based on TE, a reported energy expenditure from a powermeter might very well add up to quite a different total energy.

Example:
Based on one of my own rides: 2 hours total, mostly endurance with 4 muscletension workouts (5 minutes each) thrown in.

SRM-data:
Work: 1503 KJ (yes...I know I'm a slacker ;))
Duration: 126 minutes
With TE = 25%: MW = 6037 KJ (11,45 KJ/min)
With TE = 20%: MW = 7546 KJ (14,31 KJ/min)

This is quite a span. Given that my TE hasn't been lab testet, there is pratically no way to know for sure what my MW was.

Turning to the other option under discussion: Polars OwnCal method. Evidence is available to suggest that this method has some validity(4). Some of the research shows quite respectable accuracy: "the error of estimate (mean+SD) for OwnCalS was -0.7+1.3 and -0.3+0.8 kcal/min for men and women respectively". Still quite a span though, and MW might vary accordingly.


What to do?
Well for any of the approaches to work you need to narrow the factors that influence the predictions...obviously ;)

The powermeter method would seem to only need you to determine TE and you be flying. Given the evidence in (3), a more sofisticated algorithm taking intensity and pedal rate into consideration might produce quite valid results.

Polars OwnCal relies (as far as I can tell) on weight, max-HR, VO2-max (or Polar ownindex), and your own interpretation of atlethic ability. The Polar S-series has protocols for estimating these values.

My personal protocol is currently based on the Polar, and is very simpel: Based on the HR-monitors estimated MW I consistently go with a daily 2000 KJ dificiency. If I continue to drop weight at around 0,5 KG pr. week the protocol is working :p. I update weight frequently, VO2-max every 4-6 weeks and max-HR every 6 months. So far(2 years and running) quite stable and results are as predicted.

The same protocol could be used with a powermeter, perhaps using, different TE's in base, build and transition-phases. Going with a TE of 25% might get you a long way though!



----------------------------------------------------------------------
To anyone gotten this far, I apologize for the lenghty post, and I hope I got most of it right :D


References:

(1)
http://web.archive.org/web/20040201233725/http://www.midweekclub.com/powerFAQ.htm#Q23

(2)
http://jap.physiology.org/cgi/content/abstract/38/6/1132

(3)
http://jap.physiology.org/cgi/content/full/93/3/823

(4) http://support.polar.fi/PKBSupport.nsf/ALLDOCS/42256C2B001E0F6A422569BA0037881B?OpenDocument
 
Mike_Rides_Red said:
My polar S-720 saids at 194 bmp (when my max is 204) that i am burning 911 calories an hour. Also i rode 3 hours quite intensively and it said that i burned about 2000 calories. Is all this possible cause if it is i need to eat alot more calories. How many calories are you guys burning?
I have a Polar 725, and I think that the calories consumed is an estimate, based on all the personal data you enter into the HRM. And I think the estimate is probably close, at least in the ball park.

I took a short ride yesterday, and I used 1042 calories in 55 minutes. Sounds close to me, considering the 20 to30 mph wind I was riding into for at least half of the ride.
 
OKpro said:
My Powertap says that I burn about 1000 kcal/hr doing my endurance rides. I ave around 280 watts at a ave HR of 145-155bpm. The amount of kcal's you burn is dependant on the energy you are using i.e watts.... Your HRM is just making a guess.
at 145lbs, and 280watts average during endurance rides, are you a pro? that is the same power armstrong averages during his endurance rides.

what do you time trial at? (40km)

i use a powertap too, and my endurance rides are at about 190watts average, and am 178lbs. just a cat 3
 
I turned Pro this year about 2 weeks after I got my cat 1 upgrade. If power were the only thing that mattered I would be a lot better than I am. I may have a Pro license but last year was my first year racing on the road. I lost about 15lbs this fall and my coach got me the Powertap. I have hit the weights pretty hard and it has paid off. I make 410-425 watts at LT 180-185bpm. I hoping that this year is a big year for me and my team. I am writing a column for ROAD Magazine for the 2005 season. Check out the February 2005 issue for my first column.



velomanct said:
at 145lbs, and 280watts average during endurance rides, are you a pro? that is the same power armstrong averages during his endurance rides.

what do you time trial at? (40km)

i use a powertap too, and my endurance rides are at about 190watts average, and am 178lbs. just a cat 3
 
OKpro said:
I turned Pro this year about 2 weeks after I got my cat 1 upgrade. If power were the only thing that mattered I would be a lot better than I am. I may have a Pro license but last year was my first year racing on the road. I lost about 15lbs this fall and my coach got me the Powertap. I have hit the weights pretty hard and it has paid off. I make 410-425 watts at LT 180-185bpm. I hoping that this year is a big year for me and my team. I am writing a column for ROAD Magazine for the 2005 season. Check out the February 2005 issue for my first column.
that is some serious power for someone who is 145lbs. i bet you will do well this year.
 
Thanks for the kind words. There is a lot more to racing than just making watts. I am lucky to be in a environment where I can develop without much pressure. If you doubt what I say I will send you the powertap files....


beerco said:
:eek: Can we say understatement of the year! 410w @ 145lbs = 6.3w/kg!!! The highest ever known threshold power is 6.4w/kg (see http://www.cyclingpeakssoftware.com/powerprofiling.xls ).

If this is true, you have the potential of winning the TdF someday...can I get your autograph now? :D
 
OKpro said:
I turned Pro this year about 2 weeks after I got my cat 1 upgrade. If power were the only thing that mattered I would be a lot better than I am. I may have a Pro license but last year was my first year racing on the road. I lost about 15lbs this fall and my coach got me the Powertap. I have hit the weights pretty hard and it has paid off. I make 410-425 watts at LT 180-185bpm. I hoping that this year is a big year for me and my team. I am writing a column for ROAD Magazine for the 2005 season. Check out the February 2005 issue for my first column.
Interesting that you attribute your continued improvements to hitting "the weights pretty hard". Was this your idea or your coaches?

Steve
 
OKpro said:
If you doubt what I say I will send you the powertap files....

I'm not doubting but can you blame me for being sceptical? It's not every day that someone posts "I do 6.3w/kg".

It would be pretty cool to check out a big watts file...you would drop me on an endurance ride.

p.s. note I wrote "potential" to win the TdF.
 
It was my coach's idea.... If it were up to me I would just ride but they have a weight lifting plan that I followed. I really hated lifting but I guess it paid off. Since I just got the Powertap this fall I don't know where I was at this time last year in terms of power output. We kinda started from scratch this fall because I got really sick at the beginning of August and had to end my season early. It was alright because being my first year racing on the road full time my body just kinda feel apart after like 80 days of racing....
So, I focused on losing as much weight as possible while I was getting healthy and I guess I didnt really lose any power. I live like monk and work part time so my life revolves around training and recovery. I haven't been racing that long so I still dont really understand what all the numbers mean.... I am just hoping that all my hard work pays off next season.



Steve McGregor said:
Interesting that you attribute your continued improvements to hitting "the weights pretty hard". Was this your idea or your coaches?

Steve
 
OKpro said:
I haven't been racing that long so I still dont really understand what all the numbers mean.... I am just hoping that all my hard work pays off next season.

Hint: 6.3w/kg* = potential to set the hour record, win the Tour and any mountain stage.

Get yourself noticed so you can get a coach who really really knows what he's doing. You've got the numbers to go far, don't let some bonehead coach blow it for you in the weight room.

*I should note that you've got to be able to hold that 6.3w/kg for an hour to achieve those things.

You should go to this site: http://lists.topica.com/lists/wattage/read and hang out, perhaps introduce yourself. You can learn a lot there.
 
Thanks for the vote of confidence.... I don't know anybody in this sport. I haven't really been around long enough to meet anyone. I called my coach because they live close to me. I think that they have probably done a good job, I have gotten this far. I was a super fat kid when I was younger and have never done any other sports so I had no idea what to expect. Only time will tell I guess....


beerco said:
Hint: 6.3w/kg = potential to set the hour record, win the Tour and any mountain stage.

Get yourself noticed so you can get a coach who really really knows what he's doing. You've got the numbers to go far, don't let some bonehead coach blow it for you in the weight room.
 
OKpro said:
I haven't really been around long enough to meet anyone. ...

In case you didn't notice when you posted this message, I added some info to my last post. Go to wattage and introduce yoursolf. If your threshold is really 6.3w/kg you should be able to make some friends really quick.

If you don't mind my asking, what's your name? Feel free to private message it to me...I want to know who to keep an eye on in the magazines.
 
OKpro said:
Thanks for the vote of confidence.... I don't know anybody in this sport. I haven't really been around long enough to meet anyone. I called my coach because they live close to me. I think that they have probably done a good job, I have gotten this far. I was a super fat kid when I was younger and have never done any other sports so I had no idea what to expect. Only time will tell I guess....
Well, I certainly don't want to poach an athlete from another coach, but I agree with Beerco, that I wouldn't want your potential talent wasted on frivolous pursuits. I doubt if I would have you spend much time in the weight room, and I certainly wouldn't attibute much of your power at threshold to weight lifting. I'd be interested to see one of your powerfiles if you could shoot it to me offlist.

Thanks
Steve
 
Alright guys, here is the info. My name is Omer Kem. I turned 22yrs old in October of this year and I weighed 144lbs this morning when I weighed myself. Steve, what is your email address?

Steve McGregor said:
Well, I certainly don't want to poach an athlete from another coach, but I agree with Beerco, that I wouldn't want your potential talent wasted on frivolous pursuits. I doubt if I would have you spend much time in the weight room, and I certainly wouldn't attibute much of your power at threshold to weight lifting. I'd be interested to see one of your powerfiles if you could shoot it to me offlist.

Thanks
Steve