Tuesday, February 18, 2014

Latest Training Aid. Virtual Power v Power

What can I say. I love using my turbo trainer now ! Yes. I sold two in the past because it's soul destroying, boring as hell.

Now it's great.  The reason is Trainer Road. 

I mentioned this before in my last blog so hit the above link if you haven't got beta on it yet.

I started off using Virtual Power to determine my FTP and all subsequent workouts were based on this. My Training plan was the Intermediate Base 1 a six week program working on the 'sweetspot' range of power output.

I got on well with this program with obvious improvements out in the real world. I did however notice that it wasn't quite right. I had been lazy with the bike setup. I should have checked my tyre pressure on the rear wheel to make sure that everytime i connected it to the turbo trainer the same amount of resistence was being generated. In reality the slow loss of air was making my workouts easier !! When I noticed I re inflated the tyre to over 100 psi and found that my FTP was actually much lower than I had thought.

Before this though I had already made the decision to get a more accurate view of my power, one that didn't care about tyre pressure, one I could use out on the road. I ordered a power meter.

I settled on the Stages power meter, I had to wait a month as they were out of stock. Many thanks to my friend and fellow cyclist John Macleod for facilitating the acquisition of the power meter.

The above one is on the bike of Richie Porte of Team Sky, they can't be that bad then I hear you say ?

The upshot is that my REAL FTP is 191, I'm more or less a beginner again :) I have restarted the six week Intermediate Base 1 program. I'm in week 2.

I have noticed that the Power Meter is very sensitive and its a lot harder to be bang on the power demanded by the workout. Even though I have reset my FTP, the workouts feel a wee bit harder. I immediately noticed that it was harder to achieve the low power 'warm up' and 'recovery' wattage. Needless to say I'm glad I went back to Base 1 and didn't plough into Base 2 !

Here's an example of the same workout, the first is using Virtual Power and the second is done with the Power Meter.

You can claerly see the 'shakier' plot of power with the second picture.

Now lets examine the heart rates. Remember the FTP has been adjusted down from 251 virtual to 191 power meter.

It's perfectly clear that I'm running a higher heart rate in the second  (power meter) picture. Remember this is a sweetspot workout, admittedly power orientated, but I feel that the HR results than in the first ( Virtual ) picture are far too low.

So there you have it. I have heard a lot of people say that the results they have had with Virtual power match up pretty good with the power meter but, maybe it's my lazy attitude to setting up, it didn't really work out for me. All was not in vain, as I said, I still made improvements out on the road and trail with vitual power.

I'm looking forward to the next 4 weeks of the program but most of all getting back out to test myself on some Strava segments in a month :)

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