|
|
Thread Tools | Display Modes |
#11
|
|||
|
|||
"VBadJuJu" none@ wrote
Highly accurate too at least as to speed (and therefore distance, avg speed etc). Recently there was one of those automated radar speed things down the street off and on for about 9 weeks. Coming down the hill on my way out to ride I could verify the read out vs the radar thingie. Bike "computers" are simple wheel revolution counters, they're all as accurate as the tire size input. FWIW, 13 - 15 miles works out to about 1000 calories at 10.5 - 11.5 MPH average for me. That sounds off by a factor of 4 or so, it's way too high unless that is up a very steep hill. You can't accurately measure calories without measuring watts, and that's a difficult thing to do, the equipment is available to do that (e.g. Powertap), but it's expensive. |
Ads |
#12
|
|||
|
|||
On Wed, 01 Sep 2004 16:56:51 GMT, "chris christanis"
wrote (more or less): I had a cheap Bell computer that did it for me but it fell off (cheap). So I bought a cateye but it does not tell you calories burned. Anyway to figure this out? Pretty much, calories burned per kilometre/mile is constant, whether you're going fast or slow. (Walking a mile burns as many calories as running a mile.) If you've kept records of your previous rides, with the distance gone and the calories your old Bell computer told you, then you can do a quick calc of how many calories per mile the old computer was more-or-less using. Then count the kilometres, and multiply by your chosen cal/mile number. The Longer version One question is, how accurate was your old Bell computer anyway... With cycling, because you can get up to speeds where air resistance becomes significant, this isn't entirely true, but it's still close enough for jazz. The key factors for bikes I'd say a - weight of the rider + bike - smoothness or lumpiness of the surface. I've looked at all sorts of sites that discuss calories/hour, and the range I've seen goes from about 30 calories/mile to 65 calories/mile. And these take no account of surface. And often faster riding uses fewer calories/mile, according to these sites. If anyone wants my spreadsheet that works out calories/mile for riders of different weights and average speeds (Excel 5 format), just contact me off-list, and when I return from my holidays I'll email it to you. I pretty much use a 38cal/km (60cal/mile) for me as a 200lb guy on a heavy bike*. (This actually prompted me to go and weigh my bike for the first time. I'd sort of reckoned it as 15kg, but it's actually 20kg (45lb) - before I load anything into the panniers or the bar bag!) So just use your mileometer, and then multiply by the number you feel comfortable with. Figures I've seen on web-sites include: ============================== Calories burnt/10 mins Woman Man Wt (lb) 123 170 5.5mph 36 49 9.4mph 56 74 racing 95 130 And on another: "Cycling burns about 0.15 to 0.17 calories per minute, per kilogram (divide your weight in pounds by 2.2 to get kilograms) of body weight, for fast riding. There is wide variation in this formula, but this gives you a start. For example, 0.17 calories/minute-kilogram x 60 minutes x 73 kilograms (160-pound person) equals 742 calories needed for an hour of fast cycling. For aerobic riding, the range is lower, around 0.10 to 0.15 calories per minute, per kilogram of body weight. Very easy recovery riding is lower yet." -- Cheers, Euan Gawnsoft: http://www.gawnsoft.co.sr Symbian/Epoc wiki: http://html.dnsalias.net:1122 Smalltalk links (harvested from comp.lang.smalltalk) http://html.dnsalias.net/gawnsoft/smalltalk |
#13
|
|||
|
|||
On Wed, 01 Sep 2004 16:56:51 GMT, "chris christanis"
wrote (more or less): I had a cheap Bell computer that did it for me but it fell off (cheap). So I bought a cateye but it does not tell you calories burned. Anyway to figure this out? Pretty much, calories burned per kilometre/mile is constant, whether you're going fast or slow. (Walking a mile burns as many calories as running a mile.) If you've kept records of your previous rides, with the distance gone and the calories your old Bell computer told you, then you can do a quick calc of how many calories per mile the old computer was more-or-less using. Then count the kilometres, and multiply by your chosen cal/mile number. The Longer version One question is, how accurate was your old Bell computer anyway... With cycling, because you can get up to speeds where air resistance becomes significant, this isn't entirely true, but it's still close enough for jazz. The key factors for bikes I'd say a - weight of the rider + bike - smoothness or lumpiness of the surface. I've looked at all sorts of sites that discuss calories/hour, and the range I've seen goes from about 30 calories/mile to 65 calories/mile. And these take no account of surface. And often faster riding uses fewer calories/mile, according to these sites. If anyone wants my spreadsheet that works out calories/mile for riders of different weights and average speeds (Excel 5 format), just contact me off-list, and when I return from my holidays I'll email it to you. I pretty much use a 38cal/km (60cal/mile) for me as a 200lb guy on a heavy bike*. (This actually prompted me to go and weigh my bike for the first time. I'd sort of reckoned it as 15kg, but it's actually 20kg (45lb) - before I load anything into the panniers or the bar bag!) So just use your mileometer, and then multiply by the number you feel comfortable with. Figures I've seen on web-sites include: ============================== Calories burnt/10 mins Woman Man Wt (lb) 123 170 5.5mph 36 49 9.4mph 56 74 racing 95 130 And on another: "Cycling burns about 0.15 to 0.17 calories per minute, per kilogram (divide your weight in pounds by 2.2 to get kilograms) of body weight, for fast riding. There is wide variation in this formula, but this gives you a start. For example, 0.17 calories/minute-kilogram x 60 minutes x 73 kilograms (160-pound person) equals 742 calories needed for an hour of fast cycling. For aerobic riding, the range is lower, around 0.10 to 0.15 calories per minute, per kilogram of body weight. Very easy recovery riding is lower yet." -- Cheers, Euan Gawnsoft: http://www.gawnsoft.co.sr Symbian/Epoc wiki: http://html.dnsalias.net:1122 Smalltalk links (harvested from comp.lang.smalltalk) http://html.dnsalias.net/gawnsoft/smalltalk |
#14
|
|||
|
|||
On Wed, 01 Sep 2004 16:56:51 GMT, "chris christanis" wrote:
I had a cheap Bell computer that did it for me but it fell off (cheap). So I bought a cateye but it does not tell you calories burned. Anyway to figure this out? Lifeform is nice software to track food and exercise. http://www.fitnesoft.com/ --- "BitwiseBob" - Bob Anderson Eugene Oregon |
#15
|
|||
|
|||
On Wed, 01 Sep 2004 16:56:51 GMT, "chris christanis" wrote:
I had a cheap Bell computer that did it for me but it fell off (cheap). So I bought a cateye but it does not tell you calories burned. Anyway to figure this out? Lifeform is nice software to track food and exercise. http://www.fitnesoft.com/ --- "BitwiseBob" - Bob Anderson Eugene Oregon |
#16
|
|||
|
|||
"Kevan Smith" wrote in message
... On Wed, 1 Sep 2004 15:26:20 -0700, "GaryG" from Posted via Supernews, http://www.supernews.com wrote: "chris christanis" wrote in message ... I had a cheap Bell computer that did it for me but it fell off (cheap). So I bought a cateye but it does not tell you calories burned. Anyway to figure this out? I've included a Calorie and Watts Calculator in my CycliStats ride log and training diary software ( http://www.CycliStats.com ). This is really obvious, but any calorie calculation uses depends on what you think the calorie burn rate is. The burn rate is also logarithmic; that is, the faster you go, the number of calories burned per unit of time increases on a logarithmic curve. Therefore, finding an accurate base is important. There are also other factors to consider, such as elevation gain, wind, bike position, weight, etc, which also go into the base. The Calorie and Watts Calculator built into CycliStats takes into account a bunch of variables, including: rider weight, bicycle weight, distance, speed, elevation gain, average headwind, rider position on the bike, rolling resistance factor, and air temperature. Average headwind and rider position are the two most significant variables (after rider weight and speed which are known quantities). The underlying calculation (from a sports physiology Master's thesis...not mine) first calculates Average Watts. It then converts that into Calories burned (and also displays calories per mile/km, per minute, per hour, and equivalent fat pounds/kg burned). The calculation can be completely automatic, or the user can override some of the assumed variables. For instance, rider position on the bike is assumed to be more "aero" as you ride faster, but you can override this assumption for each ride. Is it an "accurate" number? Well, outside of a sports lab, everything is just an estimate. But, I've compared the numbers for Watts and Calories from CycliStats with many others that I've seen, and I'm pretty confident that they are reasonable for most rides. As a test, I recently plugged in Lance Armstrong's numbers for his Alp d'Huez time trial and came very close to what I've heard reported as his average wattage output on that climb (around 450 watts!). All in all, I consider it impossible to get an accurtate measurement outside lab conditions. That's why I ignore all that stuff. A ballpark figure is good enough for me, and the really important thing, anyway, is to use the same method each time. Agreed...it's all just an estimate. For most folks, 40 calories per mile would probably be a reasonable number to use (a little more if you're heavy, and a little less if you're light). Here's a good free site to do it: http://www.primusweb.com/fitnesspart...e/calculat.htm By tracking results over time, you can get a general idea of how much you need to ride to lose or maintain weight. Of course, you also have to keep track of how many calories you eat, and that's another kettle of fish. CycliStats tracks calories burned for each ride, and shows summaries for each week, month, and year (or any other time frame you choose), along with a whole bunch of other stats. You can download a free, fully functional 30-day trial version from the website ( http://www.CycliStats.com ). -- ~_-* ....G/ \G http://www.CycliStats.com CycliStats - Software for Cyclists -- Kevan Smith |
#17
|
|||
|
|||
"Kevan Smith" wrote in message
... On Wed, 1 Sep 2004 15:26:20 -0700, "GaryG" from Posted via Supernews, http://www.supernews.com wrote: "chris christanis" wrote in message ... I had a cheap Bell computer that did it for me but it fell off (cheap). So I bought a cateye but it does not tell you calories burned. Anyway to figure this out? I've included a Calorie and Watts Calculator in my CycliStats ride log and training diary software ( http://www.CycliStats.com ). This is really obvious, but any calorie calculation uses depends on what you think the calorie burn rate is. The burn rate is also logarithmic; that is, the faster you go, the number of calories burned per unit of time increases on a logarithmic curve. Therefore, finding an accurate base is important. There are also other factors to consider, such as elevation gain, wind, bike position, weight, etc, which also go into the base. The Calorie and Watts Calculator built into CycliStats takes into account a bunch of variables, including: rider weight, bicycle weight, distance, speed, elevation gain, average headwind, rider position on the bike, rolling resistance factor, and air temperature. Average headwind and rider position are the two most significant variables (after rider weight and speed which are known quantities). The underlying calculation (from a sports physiology Master's thesis...not mine) first calculates Average Watts. It then converts that into Calories burned (and also displays calories per mile/km, per minute, per hour, and equivalent fat pounds/kg burned). The calculation can be completely automatic, or the user can override some of the assumed variables. For instance, rider position on the bike is assumed to be more "aero" as you ride faster, but you can override this assumption for each ride. Is it an "accurate" number? Well, outside of a sports lab, everything is just an estimate. But, I've compared the numbers for Watts and Calories from CycliStats with many others that I've seen, and I'm pretty confident that they are reasonable for most rides. As a test, I recently plugged in Lance Armstrong's numbers for his Alp d'Huez time trial and came very close to what I've heard reported as his average wattage output on that climb (around 450 watts!). All in all, I consider it impossible to get an accurtate measurement outside lab conditions. That's why I ignore all that stuff. A ballpark figure is good enough for me, and the really important thing, anyway, is to use the same method each time. Agreed...it's all just an estimate. For most folks, 40 calories per mile would probably be a reasonable number to use (a little more if you're heavy, and a little less if you're light). Here's a good free site to do it: http://www.primusweb.com/fitnesspart...e/calculat.htm By tracking results over time, you can get a general idea of how much you need to ride to lose or maintain weight. Of course, you also have to keep track of how many calories you eat, and that's another kettle of fish. CycliStats tracks calories burned for each ride, and shows summaries for each week, month, and year (or any other time frame you choose), along with a whole bunch of other stats. You can download a free, fully functional 30-day trial version from the website ( http://www.CycliStats.com ). -- ~_-* ....G/ \G http://www.CycliStats.com CycliStats - Software for Cyclists -- Kevan Smith |
#18
|
|||
|
|||
On Thu, 02 Sep 2004 11:51:18 GMT, Peter Cole
wrote: "VBadJuJu" none@ wrote Highly accurate too at least as to speed (and therefore distance, avg speed etc). Recently there was one of those automated radar speed things down the street off and on for about 9 weeks. Coming down the hill on my way out to ride I could verify the read out vs the radar thingie. Bike "computers" are simple wheel revolution counters, they're all as accurate as the tire size input. FWIW, 13 - 15 miles works out to about 1000 calories at 10.5 - 11.5 MPH average for me. That sounds off by a factor of 4 or so, it's way too high unless that is up a very steep hill. You can't accurately measure calories without measuring watts, and that's a difficult thing to do, the equipment is available to do that (e.g. Powertap), but it's expensive. HR monitors should be better in this regard, as at least they take into account how hard you're working (and know data like your weight, sex, age, etc.). Power monitoring would be great, too. -- Bob in CT Remove ".x" to reply |
#19
|
|||
|
|||
On Thu, 02 Sep 2004 11:51:18 GMT, Peter Cole
wrote: "VBadJuJu" none@ wrote Highly accurate too at least as to speed (and therefore distance, avg speed etc). Recently there was one of those automated radar speed things down the street off and on for about 9 weeks. Coming down the hill on my way out to ride I could verify the read out vs the radar thingie. Bike "computers" are simple wheel revolution counters, they're all as accurate as the tire size input. FWIW, 13 - 15 miles works out to about 1000 calories at 10.5 - 11.5 MPH average for me. That sounds off by a factor of 4 or so, it's way too high unless that is up a very steep hill. You can't accurately measure calories without measuring watts, and that's a difficult thing to do, the equipment is available to do that (e.g. Powertap), but it's expensive. HR monitors should be better in this regard, as at least they take into account how hard you're working (and know data like your weight, sex, age, etc.). Power monitoring would be great, too. -- Bob in CT Remove ".x" to reply |
#20
|
|||
|
|||
"chris christanis" wrote in message ...
I had a cheap Bell computer that did it for me but it fell off (cheap). So I bought a cateye but it does not tell you calories burned. Anyway to figure this out? This is a very tricky question. Having investigated this in the past, I know there is no agreed, accurate method of determining the calories used. A few observations, though. 1) Any method that does not take account of the speed at which you are cycling is pure rubbish. 2) Unless you are cycling on the flat at a steady speed, any method that does not take account of the total moved mass is pure rubbish. 3) Conversly, any method which ties the calories burned to the moved mass without taking account of the altitude gained/lost and the amount of acceleration/decelerations is pretty much rubbish. 4) Any method that does not take account of the wind speed is likely to be wildly inaccurate if the w/s is over about 5 mph (consider that if you are cycling with a groundspeed of 15mph, your airspeed will vary from 10 to 20 mph tail/head wind at this w/s. At 12 mph, the difference would be 3 to 27 mph) 5) Within a fairly wide range, you can probably find a figure or algrorithm that will give you any result you want, if you research enough sites/books/articles. The method I used to *ESTIMATE* the calorie burn was as follows. a) Find a step aerobics machine which has a calories burned* readout. b) Use an HRM and set the machine to various resistances. For each resistance setting, wait until your heart rate stablises, and note the Hr/Calories readings. c) Plot a graph of these figures d) Use an HRM that will give you a mean Hr for your ride, and use that against your graph to determine your approximate calorie burn. * Try and determine if the calorie readout is the number of calories calculated from the kg/m raised on the machine, or whether the machine introduces a "fudge factor" to account for the inefficiency of human power generation/delivery. If it is the former, it will be a considerable underestimate of the calories burned. All the heat you produce is on top of the energy used to effectively raise your body mass the distance used in the calculation. If you can do the maths, you can use the Hr/Cal figures to produce an equation, but as the relationship is non linear, it's not that easy Apart from the above, I would say that the algorithm given based on mean Hr and weight has the best chance of being accurate, although both this, and the moethod I outline above will not be too good if there is a large variation in Hr during your ride. |
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
calories burned - HRM vs. Web sites?? | Bob | General | 24 | February 3rd 06 07:04 PM |
Calorie Estimates.... | LaoFuZhi | UK | 59 | July 26th 04 07:17 PM |
Polar Heart rate monitor help | Peter Jones | Australia | 15 | April 2nd 04 02:19 PM |
Influence of weather on calories burned? | Sb083459 | General | 9 | April 1st 04 11:56 AM |
Strange fatigue again...? (long) | Mitch Pollard | General | 42 | October 12th 03 02:41 PM |