* n'at a "general extender" (http://en.wikipedia.org/wiki/Pittsburgh_English)
For those of you not well versed in the language of “Pittsburghese”, we use the phrase “n”™at” for a variety of reasons, but in this case it means “along with some other stuff”. Consider this a “side-bar” to the story I”™ve been building in this Evidence Based Cycling blog. John Macgowan wrote an article on incorporating the “grade of a climb” into your Indoor Cycling classes, and it seemed like a great topic to write a follow up for.
Power, Speed & Grade of the Hill
While writing the first book on Training with Power for the Indoor Cycling environment, it became imperative to create a system that was both practical and easy to teach from Indoors, but that could also be directly applicable outdoors. After all, the mission of Cycling Fusion™ from day 1 has been to bring these two worlds together, and the validation of how our training translates while riding on 2 wheels continues to be a Start Trek level “Prime Directive”.
To that end, my crew and I followed the same approach I have been describing each week through this blog. . So, I purchased an outdoor power meter (the iBike was the cheapest that had about a 5% tolerance for accuracy — plenty for our application. Getting 100% accuracy is absolutely necessary indoors, since we won”™t have the same power gauges outside anyway, and we just need to know that we are improving it, not that we are at 200 or 300 or 225 or some other arbitrary power number.
When I would ride outside, I would compare the wattage I was seeing indoors with wattage figures while riding outdoors. This led to a variety of research undertakings with myself and my study participants. This work on Power truly marked the beginning of Evidence Based Cycling, I just had not put a name and more structure to it at that time.
1 Watt per Pound
One of the key principles presented in the book is the notion that if we want to ride outside, or more specifically, if we want to be able to climb typical hills that cyclists normally climb outside, we need to be able to achieve a minimum of about 1 Watt per pound of weight you are carrying up the mountain (rider wt + bike wt).
Through existing math equations, we were able to create a chart that showed how many Watts/lb would be required on hills with specific grades, given specific speeds. It turns out that under 1 Watt/lb there are few hills that can be ridden at a speed of 5 MPH or greater. Below 5 MPH it becomes increasingly hard to hold the bike upright. One can just about walk at 4mph, and that”™s not “speed walking”.
Willing Guinea Pigs… er Volunteers
I was lucky enough to have a bunch of regular members that embraced the whole EBC approach to training and learning, and they were more than willing to help with the research. We first wanted to know if the chart and our math seemed to bear itself out in the real world. We used different people, at different riding and fitness levels to climb various hills with differing grades with our power meter, and we found that the numbers seemed to jive. While the testing of our own clients and fellow coaches/instructors would have been enough for us to build our training with, in writing a book for “the masses” we were compelled to go a bit further.
We wanted to establish some early credibility with both the book and our own research, so we commissioned a University Study to validate the formula and the chart in a different state with different riders, and with a Power Tap that would directly measure power instead of our inexpensive model that only calculated it.
Carl Foster, Ph.D., FACSM; is the director of the Performance Lab at the University of Wisconsin. His team independently validated the chart that our 1 Watt/Lb principle is based upon, and thus we have a solid foundation for using this as a good target Power goal for the average rider. Here are the final excerpts from their published paper:
Results: Predicted PO and measured PO (within the range of 140-400W) were highly related (r=0.989), with an essentially zero value for intercept (Figure).
Conclusions: Without correction for wind, altitude or the effect of additional riders, the relationship between predicted and measured PO during cycling was very strong, supporting the value of published climb equations.
Comparison of Predicted and Measured Power Output During Uphill Cycling
Carl Foster, Ph.D., FACSM; Jacob Cohen, Gene Nacey University of Wisconsin-La Crosse and Cycling Fusions.
Implications for Indoor Cycling Instructors
Given that there are no real hills and real grades in an indoor cycling room, one must artificially create the feeling by adding resistance. With the spate of power indoor cycles there are now on the market, using the Speed & Power Chart, and specifically 1 Watts/Lb as a target, and the concept of Watts/Lb as a training parameter can provide a ton of useful options for cueing climbs or even entire classes.
Originally posted 2012-06-14 05:42:48.
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- Blog Post #10 Baseline& Performance Testing - June 29, 2023
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