When the nice guys at CycleOps offered to lend me a set of powertap wheels, I was seriously excited. Ask anyone who sits anywhere near me at Evans HQ – I think I was dancing around our office for several days.
Why do I want to train with power?
I took up cycling in 2010 to race triathlon and after a couple of seasons realised I’m not a natural runner and I’m rather a fan of my bike, so now I’m focusing on that. I soon discovered, however, that training on a bike is a little harder to measure than swimming and running. You can fit a speed/cadence sensor to your bike on the turbo trainer – but on mine the resistance tends to alter so it isn’t that accurate. You can measure your speed over a set course outside – but the strength and direction of the wind is always going to have an effect.
I’ve been intrigued by training with power for a while, but there were a few barriers:
1) It’s expensive
2) I didn’t think I was ‘good’ enough a cyclist to be using a metric employed by the ‘serious’ guys
3) I thought it would be complicated
Number one is a tricky one to answer. Anyone tempted to play with power who cant quite get over that hurdle, should have a go with the PowerCal – which uses really clever science to help you train with power via your heart rate. Luckily for me, I answered no1 with a loan from CycleOps – and I hope this blog reassures anyone who’s over that hurdle that 2 and 3 were just wrong. If I’m not good enough – well – power will help make me better! And it’s not complicated; it just takes a little bit of reading and understanding.
What is training with power about, and why do it?
A power meter measures, in watts, exactly how much force you’re putting through the pedals. It’s an accurate way of setting zones you can then use for training. Unlike measuring improvement based on speed (affected by weather) or heart rate (which is very useful, but like any other muscle, your heart is affected by many variables, like heat, hydration, and even just how tired you are) – you can measure power and know it as a definite and total measure of where your fitness is.
After a short phase of testing to find you limits, you can then use the power meter to set intervals at a wattage that is just what you can sustain. You can also then use the power meter to test yourself – so for example, you might ride as hard as you can for 20minutes on a stationary trainer – work out your average wattage over that time, then repeat the exercise a month later – in the hope your average has gone up.
The power meter is also really handy for helping you to work out were your strengths and weaknesses are. I’m using a book by Hunter Allen and Andrew Coggan called ‘Training and Racing with a Power Meter’, in which they’ve produced a chart to show what sort of power to weight ratio (you work this out by dividing average watts by your weight in KG) different category riders generally manage to produce. Looking at average wattage over a 20minute test for example, vs a 30 second max effort – I know now that I’m ‘ok’ at hammering out a hard effort for 5mins or 20mins, but I’m off-the-scale- bad at going all out for 30 seconds (genuinely I’m not on the scale..). Given my time trial background, this doesn’t surprise me. But it does surprise me how extreme the difference is. Training with the power meter tells me I need to get better at those short, sharp, all out efforts.
The chart looks like this. I’ve yet to do a ‘test’ to work out where I am exactly, but using the data I’ve collected over the last week, the software has already given me my ‘max’ power to weight ratio over set period of time. Using what I’ve got so far, I’ve marked about where the computer says I am.. I’m a bit sceptical on the 20min and 5min intervals, and looking forward to getting accurate data when I’ve done ‘the test’ (basically pedalling for that amount of time..) – but look at the difference?! It’s clear what I need to work on:
The power meter also tells you lots of other snazzy things. It breaks down distribution over a ride, telling you what % of the ride you did at peak pace. It gives you a ‘Training Stress Score’ so you know, at the end of a ride, how much pressure you’ve put your body under (and therefore when to rest).
There are loads of different types of power meters – you can measure through the cranks, via the pedals, you can fit a sensor to the chainstay. Personally, I’m using CycleOps PowerTap wheels (Evans have a selection here) – which measure your power through a sensor in the hub. Set up for this was really just about as easy as slotting in a new pair of wheels and attaching a CycleOps Joule computer to the front of my bike:
I’ll admit a minor complication during set up – in that the powertap records data when either your front wheel is moving, or you are using the heart rate monitor. So it took me a little bit of time to figure out why I wasn’t getting any readings as I spun the wheel with the bike still on the workstand. That overcome, I was good to go. I knew I’d want to look at data pretty quickly, so I popped over to the website and used the link that come in the box to download the software. Not bad.
The first ride was something of a novelty. I’ll be carrying out a couple of tests soon to work out what wattage I should training at over set intervals over the next couple of weeks – but first instruction from a knowledgeable friend of mine was just to get used to using it. So I basically had a license to do my normal session exactly as I would. I did 8 x 2min intervals and 3 x 1min intervals – and it looked like this:
It all looked a bit scary. So I decided I should maybe un-tick a few boxes:
The software then picked up points from my ride and worked out my max wattage and then wattage over 5 secs, 30 secs, 1min, 2min, all the way up to an hour. Neat, huh?
On Saturday I had a race at Cyclopark in Kent- it went ok (results still not published…) and after the race (obviously the hardest i’d ridden with the power tap) I was able to upload data and compare all my peaks with that of the last session.
So far, I’m just testing the water with the power meter. The more you get to learn about the software and the data, the more you can discover about yourself – your strengths, weaknesses – and more importantly how to improve. Next week I’ll do a test to work out what wattage I should be doing my intervals at – so I can really use the powertap wheels properly to my advantage.
Looking at the above – I need to improve A LOT. But it’s good to know my trusty powermeter is going to be on hand to help me.
For the other blogs in the series – check out:
2/3) Using the data: http://bit.ly/13t5mHr
3/3) Using the data for the season and beyond: http://bit.ly/15vorpI
(Michelle works in Marketing and also blogs at www.trainbynumbers.blogspot.com )