RoadBikeReview.com's Forum Archives - General


Archive Home >> General(1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 )


caloric expenditure while cycling(11 posts)

caloric expenditure while cyclingjust starting out
Mar 13, 2002 1:56 PM
can anyone recommend a good resource for determining caloric expenditure during different cycling intensities? i'm trying to map out a smart diet for myself and having some trouble since i don't really know how to estimate the number of calories i'm burning...
Try this website...Pedal Jockey
Mar 13, 2002 3:05 PM
http://www.stevenscreek.com/goodies/calories.shtml

I had another one that I used before I bought my HRM, but I cannot seem to find its website.

PJ
Download Lifeform Fitness SoftwareRollinFast
Mar 13, 2002 3:41 PM
I use a software call Lifeform. You can download it on the internet. It is a really cool program.
Rough numbers ...Humma Hah
Mar 13, 2002 3:53 PM
... I use, for the cruiser, a figure that was determined years ago on relatively inefficient bikes: 50 calories per mile for the typical adult male riding reasonably hard.

The figure may drop to 35-40 calories per mile for roadbikes, unless ridden at a race pace.

You can probably add another 20 calories per 100 ft of climbing.

A lot has to do with how hard you ride. I checked these guestimates against some figures at analyticcycling.com, and came out pretty close. However, if I dropped the speed to 8 mph (my wife's speed) the energy expenditure per hour dropped to couch-potato levels, and the energy per mile was very low. Its all about wind resistance. Faster means more calories, both per minute and per mile.
re: caloric expenditure while cyclingHoward2
Mar 13, 2002 4:24 PM
I used equations from:

http://www.halcyon.com/gasman/energy.htm

To build an excel worksheet that calculates calories based on rider & bike mass and total ascent. I'll send you the worksheet if you'd like (email me at snell@unm.edu).

I've been using a Polar HRM which estimates calories based on measured HR, mass, and some other characteristics. The equations listed above calculate values that are routinely lower than those reported by the Polar HRM by about 25%.

Howard
Here's the equationKerry
Mar 13, 2002 5:14 PM
calories/hr = [Vg*W(.0053 + %G/100) + .0083(Va^3)]*7.2

Where Vg is your speed in mph, W is your weight in lbs, %G is the grade (expressed as 0.06 for a 6% grade), and Va is your speed through the air. The 0.0053 constant accounts for all friction terms (bearings, chain, tires, etc.). The 0.0083 constant accounts for all wind drag. Both of these assume a racing position on a racing bike. A clunker bike or a more efficient riding position will change these numbers, which are averages anyway.

In English, calories per hour equals speed times weight times the quantity 0.0053 plus grade plus 0.0083 times speed through the air cubed, all time 7.2. The Va term takes into account the added work due to working against a head wind, but recognize that the wind you actually face on the road is probably only 1/3 of the "posted" wind speed. For example, if you are riding 20 mph into a "15 mph head wind" you probably are only experiencing 25 mph for calculating work. The reason for this is that the reported wind speed is taken 30 feet above ground and well away from buildings, hills, trees, etc. When you're riding, you often have things that block the wind and wind speed near the ground is much less.

For reference, a 150 lb rider at 20 mph is burning about 600 calories per hour (30 caloried per mile).
Here's the equationjust starting out
Mar 13, 2002 6:25 PM
that is exactly the information i was looking for. a lot of what i've been able to find so far has been way too simplistic. thank you!
Very interesting - question please....muncher
Mar 14, 2002 9:47 AM
Firstly, it seems to me (a layman) odd that the heavier the rider, the less the calories consumed - I would have thought the other way around. Why is it thus?

Secondly, out of interest, do you happen to know the "equivatent" equation for running?

Thanks.

M.
For MuncherKerry
Mar 14, 2002 5:33 PM
Sorry I can't reply to your message directly, my ability to post is compromised right now. Anyhow, I don't get your question. The equation clearly gives higher calorie consumption with higher rider weight. The first element is speed times weight times (1 plus grade). Increasing weight = increasing calories.
For Munchermuncher
Mar 15, 2002 4:00 AM
Kerry,

Thanks for the reply. Was reading that after a very long day and doing the maths in my head and got a wrong answer (3 times though - consistent at least!). You are right of course.

Still be interested to know where you got the info from, and weather you have similar for other sports, particualy running and rowing?

Thanks.

m.
re: estimates here for caloric expenditure while cyclingFrank
Mar 14, 2002 8:36 PM
Here is a formula that came from Bicycling magazine a while back.

First, note the average speed of your ride (20 mph for example).

Second, find the coefficient of that speed in the table below (.0891 cal burned per minute) and multiply that coefficient by your body weight (180 lbs. for example) for a calories burned per minute total of 16.038.

Finally, take that number (16.038 cal per minute) and multiply it by the number of minutes ridden (60 for example) for a total of 962.28 calories burned in a 60 minute ride at an average of 20 mph for a 180 lb. rider.

Avg. Speed -----------Coefficient
(mph)------------(cal per lb. per minute)
8-------------------- .0295
10------------------- .0355
12------------------- .0426
14------------------- .0512
15------------------- .0561
16------------------- .0615
17------------------- .0675
18------------------- .0740
19------------------- .0811
20------------------- .0891
21------------------- .0975
23------------------- .1173
25------------------- .1411

Hope this helps!

Frank