I had a tiny bit of panic going on last week.
You see, I moved house fairly recently. Before the move, I was doing my VO2 interval reps at 250-230 watts (the range is that way round because they start at 250 and sink to 230!). I know that’s a fairly small number, but please be kind and remember I’m about 5-10% down on watts when on the turbo.
On arriving at my new home, I set myself up in my lovely turbo room, and got ready to suffer. I decided, after all the hustle and bustle of moving, that a ‘Manual Zero’ was a good idea. This is where you tell the PowerTap to reset its torque (or something like that), and it’s actually advised that you do it before every ride. This done, I did my session. I didn’t turn auto zero back on…
To my horror, the numbers started at 225 watts, and sunk to 204. Oh dear- I thought! I’d actually been on antibiotics and had a week off training, so I thought I must be really lacking in form.
Session number 2 – a 2 x 20. With my heart rate pumping up to around 185 bpm by the end of each rep, you would expect that I’d be seeing some decent numbers. I always get low figures on the turbo for longer reps – so what outside would be around 205 watts is often about 180 inside. What I actually saw on the screen, as an average for the end of the session, was 160 and 140. Oh, oh dear oh dear..
Next up, and by this point I’m convinced there is something wrong with the PowerTap, came a round of 5 x 3min intervals. The first burst of each sessions saw me hitting a HUGE (tiny weeny) 220 watts, and by the end of 3mins I had sunk to 174 watts. Horror.
I tweeted PowerTap – who were amazingly quick to respond. Being a social media/content/customer engagement person/guru/rep for a large bike chain, I know that tweets can be a great way to communicate as long as used correctly (eg POLITELY, people…), and PowerTap got back lightening fast which was really impressive (seriously guys, damn good job):
The suggestion was to send my beloved piece of hardware back to PT towers for some love. But first, I decided to check it against my boyfriend’s (ok – fiancé’s – but we find that word overly formal) Power2Max cranks.
I sat biting my nails as he got on the turbo, with his cranks and Garmin, as well as my PowerTap and Joule, reading out identical figures. Sitting comfortably at 200 watts, he ramped it up for 10 seconds and got similar numbers in the early 500s.
Oh dear – is it me – I wonder?
The only available option left was that my lack of returning the auto zero function to the ‘on’ position may have caused the issue. You see, the Power2Max vs PowerTap test had been carried out over about 4minutes, so there was no time for heat or other variables to affect the PowerTap, which is what auto zero accounts for.
Yesterday, I spend my day with thoughts drifting towards my evening session. I now knew the PowerTap was not faulty, and all I wanted to know was if I was in fact, in some way faulty.
Arriving home, I got on the turbo. I ran a manual zero – torque was 507 (it should be between 500 and 520, so I’m told). Then I turned auto zero ON. I warmed up, and began rep number one. And? Success! Back to normal – neither me, nor the PowerTap, were broken.That, my friends, is the power of auto zero.
This little foray into dodgy wattage taught me more than just how to auto zero.
My sessions without correct numbers felt hard to judge, and easy to give up on. With only RPE to go on, I could almost hear myself thinking “there is no number to tell you that you’re not giving your all to this rep, so why not just take it down a notch and make it hurt less?” That’s a weakness in myself, of course – but it won’t make me faster. The inability to do that is the magic of training with power.
I’m not suggesting training without power is ‘easy’ – I did so for years, training with RPE and just working at a level that felt right for the interval. Now that I’m used to power, I rely on that number, and returning to training with the right figures in front of me was both painful, and a relief. I finished every interval with my nose on the bars, just wanting the minutes to end – trying to keep the numbers as high as I could. And that is how it should be.