Understanding Virtual Power

Dear Ms. Agony,

Welcome to a whole new world of PAIN, MISERY and AGONY! And - most importantly - serious fitness gains and results out on the road!

Using can virtual power can help you train at the right efforts during your workouts and, with hard work and a smart approach, improve your power and fitness objectively.

As a rule, we've got all the answers in our Help Centre. But let me be your guide...

setting your bike up for virtual power

Make sure you've configured your bike and device correctly to get the most out of the virtual power feature. Here's a short video on how: 

... and let's rewind a bit. In order to understand virtual power, let's first look at power.

Simply put, power, which is measured in watts (w), refers to how much work you're doing on the bike - how much energy you're putting through the pedals. The harder you work, the more watts you're generating (with some exceptions). It also means you're going FASTER, assuming you're on flat terrain or on a bike trainer.

The relationship between speed and power output is where virtual power comes in.

First, make sure you're using one of our compatible trainers.  Next, make sure you set up you bike with the appropriate speed sensor. Make sure to read the setup instructions here. Lastly, make sure you sync those sensors to our app! Here's how. Now you're ready to start training with virtual power. You'll be accountable to hit some objective numbers - lucky you!

OK, but... what am I capable of?

Good point. It's all well and good to have a power meter, but how do you make sense of the numbers? Is 100 watts (w) good? What about 200w? 862w? 1437? These numbers, in isolation don't mean much. The next step is to determine how long you can sustainably hold a a certain wattage over a period of time. To do so, you need to take a Functional Threshold Power (FTP) test.

FTP, eh? I've heard about this...

If you spend any time in cafes around other cyclists you might have heard this term bandied about. Knowing your FTP is important. Understanding what it means in also pretty important. Good thing we've got a bunch of answers on FTP in our Rubber Glove FAQ blog post. Read it before going any further.

Rubber Glove. This brings me to my next point.

Together with Dig Deep Coaching, we've designed a 20 minute FTP test called Rubber Glove. You subscribe to the app, so you have this video available at your fingertips! Stream it anytime, or download it for later use. We recommend you download it because any streaming hiccups can be both frustrating and lead to inaccurate numbers.


This looks HARD! Any tips?

Rubber Glove is brutal. After a relatively pleasant warm up and a series of cadence drills, you will need to turn yourself inside out over the 20 minute test. Like anything, after a few tries, Rubber Glove gets... well, not easier but less apocalyptic.

That said, you can do a few things to get the most out of yourself during this test.

  • Pace yourself at the start. If you go too hard too early then you'll blow before the end and the results will be off. All part of the learning curve, so don't worry too much if you blow on the first few tries.
  • Eat properly in the lead up to the test. Your muscles needs enough glycogen to produce the energy required. I highly recommend our nutrition guide Eating to Suffer for expert advice from sports nutritionist Alan McCubbin.
  • Be hydrated but be careful not to drink too much! Your gut can only drain so much fluid over an hour.
  • Be fresh. It's a good idea to ride this test on fresh legs, so if you did a big effort in the previous 2-3 days you may not hit the numbers you're capable of. At the other end of the spectrum, don't go into the test after days of inactivity. You'll be flat. With more training and experience, you'll learn what works best for you.
  • Use a fan to help keep your core temperature down. If you overheat, you will feel like you're suffering without actually generating any additional power. Stay frosty.
  • Get in the zone. This is a flippin' hard effort and one not to be underestimated. Mentally prepare yourself for how much pain, misery and agony you will need to endure. Push beyond your limits in the last minutes of the test - you may surprise yourself.
Rubber Glove done. Crushed it, and myself. Now what?

You've done Rubber Glove. OUCH! Our app has made the calculations and determined your functional threshold. You now know your FTP and are on your way to smarter (and harder) training. Our Suffer Scale can be mapped to your power zones and each effort targeted to a certain percentage of your FTP. The beautiful thing is that our app will make the calculations for you and prompt you to target a certain wattage according to the intensity of the interval. It's all quite scientific. We even have a chart to help you make sense of it all. Click it to view or download a larger version.

As you can see above a 9 on 10 effort, for example, corresponds to 120% of your FTP. If your FTP is 200w, then you'll be prompted to target 240w when it's time for a 9 on 10 effort.

...speaking of 9 out of 10 efforts, have you heard of our video Revolver...

C'mon Minion, anything else (before I try Revolver)?

Yes. You remember how I mentioned that virtual power was a function of speed? Well, you need to keep the variables that determine the speed of your back wheel (as it spins in your trainer) consistent. The rolling resistance is the factor that will determine this consistency. There are two key things that you can do to keep your rolling resistance consistent and you virtual power accurate over time:

  1. Keep your tyre pressure consistent. If your tyres were at 90 psi for your FTP test, make sure your tyre pressure remains as close to 90 psi. This is done best using a pump with a pressure gauge.
  2. Keep your 'trainer pressure' consistent. Trainer pressure refers to the contact between the turbo trainer and the rear tyre. To achieve consistent trainer pressure, make sure you adjust the 'roller' equally every time you install in the bike on the trainer. 
You're now ready to train with your very own FTP based on virtual power.

So, apart from being afraid, you should be excited. You now have some very powerful tools in your training routine. Enjoy!

... All this talk of Rubber Glove makes this Minion want to suffer. If you need me, I'll be a flogging station 32! 


Jared McClintock
Jared McClintock


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