What's your wattage?

[aicabsolut]

Have you done an FTP test? What is your FTP (functional threshold power, or approx. your hour TT-effort power)? It's getting to be computrainer season for me, too. I haven't tested in a long time and am thinking I need to compare to at least one test out on the road with a borrowed power meter. It seemed like I was chronically underestimating my FTP last year. Either that, or I was just testing poorly compared to my performance on the CT courses.

What does your avg. wattage translate into as W/kg (if you don't mind me asking)? I think over a 60-90 min CT workout last year, I'd tend to average around 3 W/kg.

[limewave]

Have you done an FTP test? What is your FTP (functional threshold power, or approx. your hour TT-effort power)? It's getting to be computrainer season for me, too. I haven't tested in a long time and am thinking I need to compare to at least one test out on the road with a borrowed power meter. It seemed like I was chronically underestimating my FTP last year. Either that, or I was just testing poorly compared to my performance on the CT courses.

What does your avg. wattage translate into as W/kg (if you don't mind me asking)? I think over a 60-90 min CT workout last year, I'd tend to average around 3 W/kg.

I'll have to pay attention to all the numbers when I go this week and report back. Being that my bike computer has been broken the last 3 months, all this information/feedback is really exciting to me.

[aicabsolut]

Well you can figure out your avg. W/kg if you know your weight in kg. Pure watts don't mean a whole lot except for max power for sprinting or maybe other small intervals. W/kg gives some more information. And your FTP is probably the most important number for using power as a training tool...which is why I want to be sure I get a better estimate of my FTP this winter training season. I'm just not ready to spend so many hours indoors yet!

[limewave]

Okay, so I'm at 68kg right now. So the W/KG would be 3.35?

How does one figure out FTP?

Thanks!

[aicabsolut]

I think a lot of people use a 20min time trial effort test minus something like 5% to estimate FTP. Friel advocates a 30min test: http://www.trainingbible.com/joesblo...and-power.html and argues that the average for a 30min solo TT effort is really FTP (what you should be able to maintain for an hour or 40km TT). I think this depends on how good you are at pacing for a 20km TT.


The reason I asked about your W/kg is because it's easier to compare that number across a population of people who aren't the same size for varied terrain than raw power, except when you're talking about max power. Max power is pretty hard to test on a computrainer, though, because the bike doesn't move and you can get some tire slip.

[chicagogal]

3.3 W/kg for me (FTP) at the beginning of last road season. I am hoping that number has gone up some, but I don't train with power on the road and have not yet moved indoors for winter training on the CT.

I think I'll give myself a couple of weeks of training at my "old" FTP to readjust to the CompuTrainer, and then I'll re-test using 95% of my 20min number as my FTP.

[TxDoc]

Actually the best way to determine your FTP is to do the FTP test, which by definition is a 1 hour time trial. So the golden rule would be - you want to know your FTP? Do a 1h time trial as hard as you can go and measure average power over the 60 minutes.

For some reason, a lot of people seem to not want to do the actual 1h TT, so they resort to other shorter tests like a 20' test, or a 30' test, and such. I think Coggan listed somewhere all the methods to calculate FTP and how each one is less accurate than the actual 1h TT.
Taking 95% of your 20' test average power will give you an approximation of your FTP, but keep in mind that some people test better than others at 20 minutes. In other words, if you really do your 60 min TT and your 20min TT, you may find out that your FTP is actually 97% of your 20min or maybe 92%, or 94%, or who knows. It lies usually between 92 and 98% - but when you talk time trial you talk seconds, so that 4 or 5% difference may be really significant.

Also be aware that what you see as 'average power' from a ride or CT training session is usually higher than your actual FTP.
This is especially true of road racers as opposed to time trial specialists. The old coaches when we were young used to say that if you spend more than 70% of your race pedaling, then you are doing something wrong. Meaning that you should coast, draft, sit in and rest for a good portion of your race, and be ready to attack full-speed when needed. So over 1h of race or ride time, you will spend some significant time resting, and then be able to produce a higher power output in the remaining time. If you had to pedal all the time, your power output would be lower.
The main reason is that FTP is your sustainable power at threshold, when you have to maintain that power output for the whole hour. On the other hand, when you are doing your road race, or your regular training sessions - you can alternate the surges with recovery periods where you sit in or draft or rest. So when you look at your graph, you will see spikes in wattage that show the surges, often leading to the anaerobic zones - and then recovery periods at low wattage when you rest or when a teammate is pulling you along on a race. At the end of the race (or workout), the average power may be higher than what you would be able to sustain on your own without rest and without breaks.
Makes sense?

Some people resort to normalized power to try and extrapolate an average number that represents what would have been your average power if you had a smooth ride sustaining the pace (instead of 'intervals' or 'surges'). Same as above (and for many of the same reasons), the normalized power often tends to be a higher number than your FTP would be, if you were to actually measure it by the 1h TT definition test.

It takes some time if you are not used to ride 'all out' for a while, but my suggestion would be to really do a FTP test if you want to determine FTP. Yes, it is painful, but then time trial is always painful, so there's not much of a choice - and at least it will give you believable numbers.

Last, there are a few issues with measuring wattage on computrainer as opposed to using a power meter on the road (srm, quarq, powertap, whatever), and this is due to the fact that the bike is anchored to a trainer, as aicabsolut mentioned earlier. MAP tests on computrainer do not work that well. Max power jumps work even worse. FTP however can be done on the computrainer, although it may give you a result that is slightly different than what you will see if testing on the road. It will most likely be in the 7-8% difference window, so if you can live with a small % error, it will work. If your goal is to race TT, then that error is too much, and I would forget the computrainer and use SRM or PT, much more reliable.

As per how to gauge your average power/weight at FTP when compared to other people, there's a table on WKO that does that automatically. You can also just look at the printed table on Training Peaks and find your FTP there to see where you stand: the article is at http://www.peaksware.com/articles/cy...profiling.aspx and the table at http://www.peaksware.com/media/69406...ofiling_v4.xls

Hope this helps, good luck