As the temperatures drop I still ride my bicycle to and from work every day. However, it becomes very difficult to do proper training due to ice and snow on the roads and the temperatures: I get exercise induced asthma when I breathe too deeply in cold weather. The solution? My basement and a stationary trainer. But not just any trainer. As a triathlon geek it will come as little surprise that I have a ‘Computrainer’ which is connected to my computer. The computer runs a program which simulates different courses, and the Computrainer adjusts the load on my bike so as simulate the conditions on the courses, increasing efforts on the upgrades, and decreasing on the downgrades. But that is just the start …
Functional Power Threshold
When I studied Civil Engineering I was taught the maxim ‘if you cannot measure it, you cannot improve it’ and I have carried that over to many aspects of life, especially triathlon training. When it comes to cycling, the key is your power output: how many watts of power you are putting out at the rear wheel. What you try and accomplish through training is to put out more power for the same level of effort, as well as by improving your overall cycling efficiency by improving your aerodynamic profile or your pedal stroke.
For training, it is important to establish your ‘Functional Threshold Power’ (FTP). This is the wattage which can be held for a 60 minute time trial and serves as a benchmark. To calculate my FTP I use 2 x 20 minute intervals, with a 2 minute rest in between. These are very challenging. If you are doing them right, after about 12 minutes the clock begins to slow down. After 15 minutes it has stopped and by minute 18 it is going backwards 🙂 Fortunately, you only do this once a month, as the test really is grim.
While some people do the test outdoors, I prefer to use my trainer. The Computrainer records the power so all I do is put in a flat course and ride as best I can for the FTP test. At the end I’ve got my power and from that I calculate the FTP. I ran my Powertap power meter (which is in the hub of my bicycle) at the same time as the Computrainer and there was a systematic bias of about 5 watts higher with the Powertap than the Computrainer, which is important when it comes to racing.
With my FTP established, I then do different rides at certain percentages of my FTP in order to try and increase the FTP level. With regular testing I can then monitor my progress – or lack thereof 🙂
Another really neat feature of the Computrainer is its ‘Spin Scan’. This uses the torque produced on the pedals to monitor you pedaling efficiency. People who are very smooth cyclists have a fairly constant level of pressure on the pedals throughout the stroke, whereas ‘stompers’ have distinct high and low points. I am a stomper of course and if you look carefully at the figure below you will see in the top right a ‘peanut’ shaped profile–if I was a smooth peddler it would be more of a circle. What is interesting is that when I get out of aerodynamic position it becomes more of a circle. One goal I have over the winter is to play with my peddling efficiency.
The SpinScan also shows that my right leg is doing 48% of the work , and my left 52%. This is likely a reflection of the 4 x knee operations I’ve had on my right knee which have caused me to favour the leg. I’m using a set of Powercranks on my road bike for commuting over winter. These force each leg to work completely independently and will hopefully balance things out. I will do a post on those later.
With all this data one can also improve ones bike fit. This is done by altering different elements-for example your seat height-and then seeing if it has a positive or negative impact on your power output for the same level of effort. It is interesting to see the results for some people who report 10% or more changes in power output by adjusting some basic aspects of their bike setup.
Computrainer is great for simulating the experience of cycling on different courses. I was able to preview the Ironman Switzerland course before the race, and I’ve already been checking out Ironman Louisville (looks to be much flatter course than Switzerland). I like to supplement this with the ‘Spinerval’ DVDs. These are structured training sessions with cyclists which are very challenging. My favourite is ‘Suffer-o-rama’ (#3) which is a very hard interval session. It is an easy gauge of my fitness since at the start of the season I cannot complete it, at least without wanting to throw up, but over time I get stronger and can complete it. There is also the Time Trial (#22) which is an FTP workout (20/15/10/5 minute intervals at FTP).
I keep myself from going mad with boredom by watching movies/TV on Lis’ notebook computer. There is a great web site www.hulu.com which streams films and shows to the Internet. I’ve also joined Netflix for the winter.
So the above shares how I’ve learned to love my basement by spending an inordinate amount of time peddling on my trainer. Let’s just hope that come race season I will see some fruit from all my labours! And in case some sharp eyed person is wondering what the use is of an aero wheel on stationary trainer, I am testing the disc wheel covers here along with my Powertap. I figured it was safer to put a few hundred miles on them in my basement before I ventured outside with them in the spring.