How many calories are we burning?

Mikebike125 said:

I do a weekly Saturday ride of 27 miles with an average speed of about 18.4 to 19.5 miles per hour (we ride for about 1:27:00). The terrain has moderate elevation changes with 3 or 4 good hills during the ride each way. My heart rate averages about 148 with a max of 180. I am wondering if anyone knows about how many calories are burned on a ride like this.

There are a lot of good online estimations like this one: http://www.nutristrategy.com/fitness/cycling.htm based on weight and average speed. You really can't use HR to estimate calories burned though it can be a clue to what energy source you used more of (fats vs. glycogen).

TV News last night showed a bespectacled dude from the University of NSW (Australia) who said they have some new research. It appears that on an exercise bike, doing short bursts of 8 seconds ( i think) of high intensity followed by a certain amount of recovery, and doing this regularly, resulted in loss of 1.5 kgs (per week?) while other guinea pigs doing normal riding on exercise bike showed 0.5 kg loss. One lady says she lost a fair bit of weight...the professor dont know why this works better, he has some theories, but tonite I'm gonna jump on my magtrainer and do 8 second bursts...and on the way home tonite, same deal. Need to lose a bit of excess weight. My bike is heavy but I can't afford the latest 7 kg carbon creation, so I wanna lose weight in my body...

There are calculators for estimating riders speed and power, like this
w3.iac.netvelocity.htmlOpen ↗

Depending how high are the hills, and are you rather drafting or riding in the front, you may get some estimate of your average power. Furthermore, the power is usually converted to calories as 1 J energy for the bike = 1 cal energy consumed by the body. I'd estimate that your power might be somewhere 200 - 250 Watts range, corresponding energy consumption of 700...900 kcal/h.

When I input my figures with 240 watts I get a resultant speed of 23.7 Kmh. If I put in 300 watts I get 27.1 Kmh. Our average speed on our ride is 27.3 Kmh. Now that is just an average so it includes 53 Kmh downhills along with 20 Kmh uphills. I wonder if my average speed correlates with that calculated speed....

Mikebike125 said:

I do a weekly Saturday ride of 27 miles with an average speed of about 18.4 to 19.5 miles per hour (we ride for about 1:27:00). The terrain has moderate elevation changes with 3 or 4 good hills during the ride each way. My heart rate averages about 148 with a max of 180. I am wondering if anyone knows about how many calories are burned on a ride like this.

it's another good reason to get a power-meter 🙂

calories per pound*minute

http://www.bicyclesource.com/body/training/calorie-burn-rate.shtml

Several years ago, Bicycling magazine published the following data:

MPH KPH Calories / lb-min
8 12.9 0.0295
10 16.1 0.0355
12 19.3 0.0426
14 22.5 0.0512
15 24.1 0.0561
16 25.8 0.0615
17 27.4 0.0675
18 29.0 0.0740
19 30.6 0.0811
20 32.2 0.0891
21 33.8 0.0975
23 37.0 0.1173
25 40.2 0.1441

Add 22 calories/hour for each 100 ft of elevation