Exercise! - Trying to figure out spinning watts

02-12-2013, 01:00 PM
My gym (well one of the three) has the computerized bikes so that we can see how many watts we are generating as a class and per bike. Now, I'm not a biker, but I am pretty active with other fitness classes.

We went for about 55 minutes and I had the tension for flats at 5-6, hills at 11 and tough hills at 14-15. My total output it said on the screen was 68.6 The only other time I have recorded was from 14 months ago and i had 38.8.

Up on the screen, for the entire class of 28 bikes for the hour the total output was 550 watts.

Something doesn't jive here and nothing I'm finding online is helpful. I'll ask an instructor when I can, but I would like to figure out what it all means because it doesn't add up quite literally.

Goddess Jessica
02-12-2013, 02:52 PM
This might help you out. From http://www.beginnertriathlete.com/cms/article-detail.asp?articleid=433

Watts = Torque x Cadence, where Torque = Force x Distance; or how hard you press on the pedals multiplied by the number of times per minute you apply this force.

Two cyclists, Bob and Bill, weigh the same, have identical bikes, identical aerodynamics and are riding next to each other at the same speed on a flat road. Because they are riding the same speed and we’ve controlled all the other variables, they are performing the same work, ie, riding at the same watts. However, Bob is mashing at 70rpm while Bill spins at 110 rpms. Bob’s pedaling style dictates that he press hard on the pedals with each stroke. But he does so less frequently than Bill, who is pushing lightly on the pedals but much more frequently.

There is more on watts at the end of the article as well.