For me, power data is most useful in training. Since having power data on my bike and the turbo, I've been able to see exactly how much I'm fooling myself into thinking I'm working hard, especially on the turbo.
Since doing a couple of maximal efforts on the Watt Bike, I've had proper targets to aim for during turbo training sessions. Previously I had been going on feel, using the RPE (rate of perceived exertion) which is a very subjective measure. Now I can use the objective measure of power. This pleases the scientist in me. I am no longer able to be fooled into thinking I'm working hard enough. The numbers stare at me from the little yellow computer on the front of my TT bike telling me to push harder, keep going, don't let up. I now know that I can go much harder than I thought I could and I can hold a sustained effort for much longer. Though on a bad day, it is very obvious that it's a bad day; the numbers stay low and won't climb up to the target no matter how hard I try.
Training out on the open roads is also improved by the use of a power meter. I can ensure I don't push too hard on the climbs but more importantly, I can make sure I push hard enough on the flats and the downhills. Though not the steep or twisty downhills, there's no way I'm going to pedal hard down something like that!
I've been out on the Bolton IM course a few times over the past weeks and I'm getting to know the spots where I can push on and where I need to ease off slightly. The power meter is always there reminding me of the effort I'm putting in and how this deviates from my optimal power. I'm looking forward to using it to slow me down at the start of the cycle leg of the Ironman, when race day adrenaline is in full flow!
Oh and, one last thing: it pays to go to time trials. A cheque arrived in the post today - prize money for 3rd place in the 50 mile time trial! (I'd need to get a lot more of those to keep me going with the amount of food I'm consuming at the moment)
