Well, here's what the book says (p. 51): "The reason for subtracting 5 percent of the watts from your 20-minute test is that FTP is defined as the highest average wattage or power that you can maintain for 60 minutes. Because some athletes have a hard time focusing for 60 minutes on a maximal effort, and those who can learn very quickly that a 60-minute time trial is not that much fun, we have found that 20 minutes is more realistic in terms of getting athletes to do more regular and higher quality tests. Since 20 minutes is a shorter time period, it incorporates more of the athlete's anaerobic capacity, however, and this skews the wattage data by about 5 percent over a 60-minute effort. By subtracting that 5 percent, you will come up with a wattage number that would be very close to your 60-minute power measure."

The test is described on p. 50.

Let me put on my wattage-lurker hat and see if I can answer that one ...

B/c your AWC will somewhat recharge in the 10 min rest between the 5 min all out effort and the FTP test. The protocol is designed to isolate changes in your AWC from affecting the 20 min effort. So you first deplete your AWC, then let it recharge a bit, then do the 20 min effort and subtract 5%. Since the rate at which AWC/MAOD recharges is largely driven by VO2Max, which in turn scales roughly with FTP, the amount of AWC recharged will be proportional to FTP rather than total AWC. So improvements in AWC shouldn't affect the FTP test, or at least not as much as if you skipped the 5 min effort and just did a maximal 20 min one.

'Nuff acronyms?

The 5% figure is just a pretty good guess. You'll find a lot of people who say their difference was more like 10%, but that's usually because they skipped the 5 min effort.

I hadn't known that. So we're talking somewhere around a Zone 2 (65%-70% of MHR) heart rate? Or is he talking of a higher heart rate where you'd fatigue at that rate if you went for even another 5 minutes?

EDIT: Just saw this quote from the book as posted above: "FTP is defined as the highest average wattage or power that you can maintain for 60 minutes." That contradicts your statement that it's a "quasi-steady state without fatiguing." In other words, if you can hold 90% of your Max HR for 60 minutes, you can do that to determine your FTP, regardless of the fact that you'll be fatigued afterwards.

That's a BIG difference. If a Cat 1 rider can hold 5 watts/kg for an hour without any fatigue (i.e. a zone 2-3) as opposed to doing it at 85-90% MHR, that's a monstrous difference.

In this context, "without fatiguing" means without having to drop to a lower power level. You'll be plenty exhausted after an hour at FTP.

It's not my statement. Both are direct quotes from the same book.


Come on, are you kidding? 90% MHR for an hour?

So it's like the initial 5 minutes simulates some of the fatigue you'd experience over the full hour, and the additional 5% accounts for the difference in anaerobic effort over the shorter time period, or something like that.

In any case, like I said, I'm just quoting exactly what the book says. I have no reason to question Coggan or Allen on any of this myself, but it would be interesting to read any reasoned arguments as to why the test might not be valid as an estimation of FTP. Until I do, I'll stick with what they say.

According to the poll ( http://bikeforums.net/showthread.php?t=287048 ), there's more than 20 people here that can do it. I can do 85-90% MHR for an hour (and do so every week) and I am pretty sure that I could do 90% for a full hour if I had someone pushing me so my concentration didn't wane.

I did it the day before Yesterday. 191 MHR, 174 average for an hour. 91%.

Oh, well that I've done (averaging 90% for a full hour). But there are times where my HR has dipped to 85% during the hour, so I consider it as doing 85%+ for an hour, not 90% for an hour. I still think i could do 90% and higher only for a full hour but I'd need a "pacer" to make sure I didn't lose concentration.

::shrugs:: OK, well you guys have much better ability to focus than I do. That's great.



Back to the question of the test procedure, and what "fatiguing" means:
That's pretty much the interpretation I had, and I don't find it contradictory to the other statement of "the highest average wattage or power that you can maintain for 60 minutes".

Here's the file - I had to rename it from Power Output Chart.xls to Power Output Chart.doc so that the forum would allow it as an attachment.

Download it, rename the extension to .xls, and you should be OK.

The FTP #s in the new chart that CP has out are too low IMO. If you can't push 4.5w/kg you aren't hanging with the best climbers.......at least in the M35+/45+ Cat IV fields in NCal and SCal races.

gene r

Sadly, from experience, I must concur (I don't know about 4.5W/kg specifically, but I know that if I were using the chart instead of actual race experience to gauge where I was, I would be very, very wrong).

4.5w/kg for how long? A one hour climb?

--Steve

Yeah, that doesn't make sense unless you're really in the mountains. Not the Michigan 'mountains'.

By definition FTP is your 1 hour highest sustainable power. So being able to hold 4.5 w/kg for one hour.

There aren't any races (other than the Mt. Hamilton RR in NCal) where you are climbing for 1 hour as most of the hilly road races require really solid 10-20 minute climbing power and the watts/kg for those efforts are far higher than 4.5 w/kg.

In fact I think if you want to do well in NCal/SCal RRs its best to really work on your ability to arrive at the base of a climb "fresh", have killer 15-20 power, and have great repeatability. I'm sure its the same in other districts that have lots of hilly RRs.

Last, there is a lot of sandbagging in the M 35/45 cat IV fields because the "open" races are sooo tough for mere mortals.

gene r

Do you have some PowerTap/CyclingPeaks examples to show where you averaged higher than 4.5 w/kg on a 20-minute climb in a Masters Cat4/5 race and still got dropped (or broke away)? That would be cool to see.

Around here (Raleigh area) there are no climbs lasting more than a few minutes. In the three Masters 4/5 road races I've won this year it has come down to being able to overpower people in the last 2-to-4 minutes of the race.

--Steve

thats well over 300 watts (~360 for me) and I know I can't hold that for long.. and I've done ok in the 4/5s on climbs.

I've never done anything more than a 4min/1mile climb. These "mountains" and "20min climbs" that you speak of intrigue me.

I've heard it discussed elsewhere, but are you guys capable of producing more power on a 20min climb than you do on the flats for 20 minutes?

I havent done one with a powermeter.. but with the small amount of riding I have done I would say yes.. There is a ~1hour 20min climb near me that I'll be doing in the next few weeks hopefully.. so i'll let you know.

Mentally I find it easier to sustain higher power numbers for longer on climbs as opposed to flats. That shouldn't be the case, but something about going up...maybe causes more intense focus. I kinda get bored in the flats.

that plus when i do them i feel worse if i look down and see 10 or 11mph (climbing) vs 18 (flat) when in reality the 10mph is producing more power.

That makes sense. In one of my races last weekend, we were hitting the 1min climb at 450ish if there weren't any attacks, and while that wasn't killing me, it still hurt, and it was easier to maintain that than it would have been on the flat.

Hey Steve -

I did a M45+ 4/5 race in mid April that is a killer w a 14 min killer climb and sections as steep as 15+%. I put out 4.66 w/kg to stay with the leaders and make it into an 8 man breakaway that stayed away for the rest of the day, but trust me when I say, the best in that group were holding back on the first climb! :eek:

While I was able to stay in contact on the 1st climb and recover on the flats after the climb I was crushed on lap 2, the second time up the climb, as I could only put out 4.3 w/kg. The 6 that went up the road just hammered me and 2 others. We chased in vain and never saw them again.

This was a TOUGH RR, but was a small field. They had so many M45 4/5s registered that day that they split us into 2 fields of 30 riders each, and we were the weaker field based on my observations. I've got believe that out of the 60 or so M45 4/5s that raced that day at least a dozen have an FTP around 4.5 w/kg.

gene r

I have a couple of teammates that race the masters 4/5 in Nor-Cal and I think the 4.5w/kg is pretty close to hang with the lead group on a climb.