Virtual Power vs Power Meter FTP

power-meter

#1

Hello Folks, Hopefully this sparks some healthy & fun discussion:

The painful reality: My power meter FTP ramp test results are Significantly Lower than my my virtual power. I did a ramp test this week with 2 computers running TR, 1 using my new Vectors & the other using good ol’ Virtual Power. The Power meter FTP was 190 & the Virtual Power was 265.

The back story: I just bought my first power meter (Garmin vector 3) after using Trainer Road’s virtual power for roughly 1 year. FWIW, I’m on a cyclops super magneto pro & I was using Garmin speed & cadence sensors. Now I had read that one should expect a drop in power when switching to an actual power meter… But i was a little disheartened to see that my virtual power “big gains” from 190-265 over the past year were probably not all that real.

Now I’ve kind of accepted that I’m a significantly worse cyclist than I thought. Just curious what others experience with the difference between virtual power & power meter results.


#2

I wouldn’t worry about it. You are what you are and you’re trying to improve.

Now you have the same power indoors and out you’ve got the best setup.


#3

Does it really make a difference? I trained for a couple of years with virtual power and had a ridiculous figure for my FTP. Retested when I got a power meter and the result was much different. The important thing is that the figure is consistent and you’re training at the right intensity. Be that 400W or 200W. And that change does not make you a significantly worse cyclist, nor negate any gains you’d made while training with vitual power.


#4

I think you are thinking about this incorrectly. Those gains were absolutely real! You are just using a different, more accurate method to assess power now. So you got a ton stronger over the past year - you built your FTP up to 190 on an accurate power meter - this just means you started lower than that a year ago


#5

Yup. Gains are gains.

Look at the same “ruler” and measure the delta on that one only. To that end, look at the percentages between your start and end point. That delta is a REAL way to measure the gains.

Having a more accurate (true to life number) is nice, but not necessarily any better. One of the only advantages of real power vs virtual power is the ability to compare to other riders with similarly accurate equipment.

Having said that, DON’T do it :stuck_out_tongue:
Focus on your own training, and gains relative your own starting point. Try to resist the temptation to measure yourself against others. It really doesn’t help much and can lead to poor choices in some cases.


#6

Wow- Thanks all for the therapy session! Hopefully this is helpful for others when they drop $$ on a power meter & have buyers remorse for similar reasons lol.

But in all seriousness, thanks for the encouragement!


#7

No need for remorse. The common mistake is to take virtual power for more than it is. Sadly, since we still call them watts, people often consider them the same as a PM wattage. Sometimes they are, but often they are not.

So, ignore the past values as they are irrelevant in an absolute sense, but the percentage gains are still what matter.

Take your new power meter, run a Ramp Test (or your other FTP test preference), and use that value as your new baseline. Use that new FTP and measure against it in the future to see your continued progress.

The simple idea is that you just swapped measuring sticks. It might as well be like thinking you switched out an old Imperial tool with a new style Metric tool. They both measured stuff, but with different values.


#8

The other benefit of real power is in having faster response to output, virtual power is dreadful for short power work.