Tuesday, November 30, 2010

Why I love my Computrainer

Today I completed another interval workout.  It was a tough workout, but that is what intervals are all about.  I did it on my computrainer – using the coaching software.  This allows me to specify the precise power that I need to generate for the whole session. 
Today’s session looked like this:-

  • Warm-up – 10 minutes
    • start slow and increase power for 7 minutes
    • hold 172 watts for 2 minutes
    • rest for 1 minute
  • Initial Set – 5 minutes - to get ready for the main course
    • 30 seconds @ 230 watts
    • 30 seconds @ 123 watts
    • repeat 5 times
  • Main Set – 45 minutes
    • 6 minutes @ 240 watts
    • 3 minutes @ 123 – recovery between sets
    • repeat 5 times
  • Cool down – 10 minutes
    • reducing watts to around 125

1hr 10mins total – the actual watts were calculated based on power from previous workouts.  The great thing about this is that it really helps to keep your focus when all you have to do is ride, the computrainer dishes out the power/pain – so there really is no cheating.  I’d find it hard to do this workout on the road or a regular trainer.  Most of the time I listen to music or podcasts whilst riding in the basement.

The cool thing is that once the workout is over (and actually even during the workout) you can see what you have done (or are about to do) – check this out…


you can easily see the green line at the bottom represents the workout power, as described above.  The yellow line is RPM and the pink line is my heart rate.  I switched off other measurements to make it easier to view.  The view at the very top is the plan for the workout – a visual representation of the description above.  You get to see all of this during the session.

It is interesting to see the curve on the HR lagging behind the watts, which is expected.  This good thing here is that the HR/watts/cadence for each interval are all taking on the same shape (except for the first part of the first 6min interval). I  guess this means that my endurance is decent, meaning that I am not really struggling to complete the last 6 minute interval, it felt about the same as the 4th and 5th.

The blue vertical line just right of middle is where my mouse is positioned, it tells me that at that instant, my power output is 255w and the HR is 166 @ 99 rpm.

I had a look at as similar workout from a few months ago.  Back then my cadence and HR were at similar levels but my power during the intervals was much lower @200w.  That is some pretty good progress.  I still have a long way to go, but

Even though my CT is around 10yrs old – it still seems to work very well.  I am looking forward to the updated software which should be available in the next few weeks.

Friday, November 12, 2010

Computrainer Power/Efficiency

I usually spend a few hours a week reading articles, blog posts and other materials.  One thing that really interests me is the whole concept of power meters.

Earlier this year I purchased a 10yr old Computrainer.  After updating the handlebar controller chip and replacing a few other parts, I now have power when training indoors! 

I can see some good progress on my power output, using a 30 minute time trial on a flat course (10 miles). I have gone up from 194 watts to 214 after 6 weeks, and after 3 months I managed complete 30minutes at 245!  This is pretty amazing, for the last test I was hoping for something in the 220’s.  So that works out to around a 25% increase in 10 weeks, a great effort. 


Whilst my power is going up, my riding efficiency is something that I have to work on.

The computrainer software has a large amount of data available, both on screen while you are riding, and of course on the computer after a workout has been completed. 
Some of the more interesting statistics are :-

  • left/right power split – which helps to make sure you are in balance
  • spinscan value – how efficient or even each pedal stroke is
  • ATA – average torque angle. a measure of where the most power is generated – in degrees from top dead center.  This is something that I am working on understanding

It is obvious that you want the left/right split to be an even 50/50 – I am right around there most of the time, sometimes it drops 48/52 for a while but for the most part I seem evenly balanced.

Spinscan and the ATA numbers are something that I have to work on.  The idea is to get the spinscan numbers as high as possible, with 100 being perfect (but practically impossible, unless you are an electric motor). 

The question that I had was is:  what is a good/bad/average/excellent spinscan numbers?

For most of my recent training – I have been in the low-mid 60’s and a few times in the 70’s.  it is generally trending upwards, but I still didn’t know if a 65 is good or not.  I found an article on YouTube (here) which suggested the following for both spinscan and ATA:-


So – I am a C in ATA numbers, and lower (a D or E) for Spinscan.  This gives me a new short-term goals to work on for the off season.  I’d like to improve my efficiency before/during base training over the winter.

I’ve also read a lot of articles about power on the bike – and almost all of them refer to the “bible” – “Training and Racing with a Power Meter” by Hunter Allen and Andrew Coggan. 

powermeter-bible2 I am really looking forward to reading this and getting a deep understanding of the whole power concept.  I want to understand as much as I can before I purchase a power meter for the bike.  I am considering waiting for Garmin to release the Vector unless is can somehow find the $$$ to purchase one sooner (not very likely).

Before I start reading this book – I am still working on finishing “Iron Fit” by  Don Fink.


Garmin Forerunner 210 giveaway – DCRainmaker

dcrainmaker is doing another giveaway, this time for a new Forerunner 210 – here’s the link november-forerunner-210-giveaway