View Full Version : Mileage Question

06-29-2005, 01:16 PM
Hi everyone, I have been asked by a member at my club how many miles we ride in a 45min class.

I told him that every class is different, we may climb the entire class, so we'll cover less terrain...

Regardless though, have you ever measured your distance? If so, how? We have Star Trac and Schiwnn bikes so we can't use the cool computers that the Lemond bikes use for this purpose...

I'm curious now...

Your help is greatly appreciated.

07-01-2005, 12:36 PM
You probably have set yourself up for a whole slew of responses from the sarcastic to the engeneering calculations needed to determine the actual distance.

Please don't be offended by my response.

If I know the participants in the class, I start with the sarcastic approach and tell them, "Zero, your bike hasn't moved an inch since you started pedaling."

I follow this by saying, "We do not focus on the distance we cover during our ride, but the quality of our training. Does the way you are riding help you obtain your training objectives for this ride?"

I finish it up with something similar to your response that it depends on a lot of factors and isn't a meaningful number since we are simulating road condidtions and not really riding a real road. A general calculation may not give a realistic number based on those factors.

I have read an old post on the old Spinning Forum where someone actually did a calculation and provided the engineering reasoning behind their conclusions.

07-01-2005, 07:27 PM
An instructor of mine who also teaches on LeMond bikes at another gym has told me that for a typical Interval Spinning class (our's are 1 hour), that you go at least 15 miles to at most 20, depending on pace, and that a strength class is usually about 13 at least to 18 at most. Usually. So if you apply that for 45 minutes, an interval class is looking at 11.25 to 15, and 9.75 to 13.5 for a strength class. He said as well that that amount is for indoor cycling only, and that that equivalent of expenditure outdoors would yield a longer distance, because of coasting. So add a couple of miles to equate outdoors.

07-01-2005, 08:39 PM
As a frequent outdoor rider, I can judge by feel and intensity. As noted, the terrain of the outdoors changes things.

The intensity of an indoor ride is very roughly equal to a moderate-to-hard ride outdoors. Call it a flat-course average speed of 19-20 mph in my current shape. (I've been strong enough in recent years to maintain a strong 22-24, but can't take the time to train nowadays.) That's an equivalent 15 miles for a steady-state indoor ride at RPE level 7-8 out of 10.

Interval rides full of sprints will be about the same, since speed would be both much faster and much slower than a steady-state ride.

A hill-climb on an outdoor bike that feels like a hard indoor ride might cover as little as 4 miles depending on the slope (like, a 10%-er). I'm no climber!

If you have a competitive racer or triathlete in your class, they'll "go farther," maybe 20. Likewise a couch potato taking their first ride might muster less than 10 miles in 45 minutes.

If you measure the size of the flywheel and assume you're riding along on that size of wheel, the numbers will be smaller. (It's smaller than a typical bike wheel). I measured the Star Trac V bike and crunched out an RPM-speed equation, but can't remember what it was.