Friday, January 06, 2006

Computrainer modeled course matches real world results

After riding the Silver Comet Trail time trial last weekend, I used the elevation data that my Polar heartrate monitor gathered during the ride and recreated the course profile on my Computrainer. The slopes on the trail are small (most range between 0.1% and 0.8%) because the trail lies on an abandoned railroad bed. I added a 5 mph wind from the west because that is typical for the trail ride.

After setting up the course on the computer, I rode it trying to keep my heartrate at about 147 for the entire 10 miles. I figured that would give me a data point between the 153 bpm and 143 bpm that I got from my real-world rides. The out portion of the ride is much slower than the back stretch becase it's slightly uphill and into the wind. I averaged about 18.5 mph going out, and 22 coming back in with the wind at my back. I think my average power was about 200 watts.

I finished the Computrainer ride at 147 bpm average heartrate and and average speed of 20.0 mph. When I plotted the new data point on my graph of HR vs speed for last weeks ride, it hit dead on the line! So now I have a perfect way to try different strategies to prepare for the time trial in Feburary. Also using the 'race against previous performance' feature, I can see how different strategies (starting out easier, etc.) relate on the course to my other rides.

It's the best possible way to squeeze out all possible speed using my average abilities.