2x20 minute FTP intervals seem pretty popular.

But if you're racing a TT at an hour or a road race at longer than that, shouldn't you be doing longer FTP intervals?

(we'll assume you're doing shorter, more intense intervals as well)

Try 3x20 @ 105% then

2x20s create stimulus leading to adaptation of FTP improvement. Just look at the zone 4 column in the Power Training Levels page (http://www.cyclingpeakssoftware.com/power411/levels.asp).

It's about the amount of time spent in a given zone. 2x20s gives you 40 minutes in zone 4. If you do longer intervals at the same intensity, it may have too big of an impact on the rest of your training week. Technically, to do 60 minutes at FTP should require a taper, so training before the effort will not be stimulating any adaptation. After the effort, some recovery will be required, so you'll likely have a day off or at least really easy.

2x20s are somewhat invasive early in the season, so people seem to stick with SST (zone 3/4 mix), which can be repeated day after day. I recently saw my gains start to flatten out with SST, so I've been doing 2x20s (four 2x20 workouts in 10 days so far), and I'm adapting to the efforts. Hopefully I'll see some FTP bumps from it.

Does that help?

1x60's @ 100% are mentally a beat down. FTP is the "best case" scenario for what you can hold for an hour, but you're rarely likely to be fresh enough to handle it.

The point of training a system is to do just enough training to provide the desired adaptation while not leaving yourself so fatigued you can't meet the desired training objectives of the following day. For most of us mortals, a 40km TT/60 minute effort would net a rest day the following day. However, I can do 2x20's and still get a good workout in the next day usually.

I'm a fan of 3x20's one day followed by 2x20's the next. In fact, I start my re-build for my summer goals tomorrow with 3x20's on Mondays from now until July. For the next two weeks, I'll just do 3x20's on Mondays. After that, I'll switch to 3x20's @ 91% on Monday, 2x20's @ 95% on Tuesday for three weeks. Then I go to 2x20's on Monday @ 100% for 3 more weeks. Fun, fun, fun :)

The point of training a system is to do just enough training to provide the desired adaptation

+1

2x20s are somewhat invasive early in the season

What does this mean? Invasive how?

Here is my philosophy:
Level 2 and 3 are for wuss. Level 1 or 4-7, as little as needed of each to do its thing. My week consists of 4 days of Level 4-7 (intervals), three days of Level 1 (or 2 days and a day off). You are either stressing your body to raise your 20min (which dictates FTP and beyond)/5 min/1 min/30 sec power, are recovering, or are not "training."
I may bump up to 5 days of 4-7 now that I no longer seem to get sore and feel relatively fresh after the hard days, or else add more intervals if I am able to maintain output through the interval set.

See http://www.pezcyclingnews.com/?pg=fullstory&id=5521
http://www.pezcyclingnews.com/default.asp?pg=fullstory&id=4456&status=true

zone2/3 is not "for wuss"
zone 1 is only good to recover slightly quicker than if you sat on your ass and does not help you at all, zone 2/3 is beneficial, I ride a couple longer rides a week trying to stay in them.

for ftp intervals I do 4x10, 3x15, and 2x20..

The point of training a system is to do just enough training to provide the desired adaptation while not leaving yourself so fatigued you can't meet the desired training objectives of the following day

Dunno, I thought it was to cross the line first.

Dunno, I thought it was to cross the line first.

Don't confuse them with the obvious Gary.

What does this mean? Invasive how?

If you're in the early training cycles, you might cause too much multi-day fatigue with 2x20s. In other words, you might not be able to do enough intensity the next day.

Here is my philosophy:
Level 2 and 3 are for wuss. Level 1 or 4-7, as little as needed of each to do its thing. My week consists of 4 days of Level 4-7 (intervals), three days of Level 1 (or 2 days and a day off). You are either stressing your body to raise your 20min (which dictates FTP and beyond)/5 min/1 min/30 sec power, are recovering, or are not "training."
I may bump up to 5 days of 4-7 now that I no longer seem to get sore and feel relatively fresh after the hard days, or else add more intervals if I am able to maintain output through the interval set.

See http://www.pezcyclingnews.com/?pg=fullstory&id=5521
http://www.pezcyclingnews.com/default.asp?pg=fullstory&id=4456&status=true

I wouldn't discount level 3 too much. These are my improvements from focusing on SST (level 3/4) at the beginning of this season:
5s: 1469W --> 1570W
1m: 669W --> 801W
5m: 368W --> 459W
20m: 320W --> 358W

I don't have the schedule to spend much time in zone 2, but if I had more training time, I'd be filling it with zone 2 and 3, for endurance and aerobic fitness.

EDIT: note that in general, I agree that intervals are more important. I just want to make sure I have the fitness to manage the training load so I don't overcook it.

What does SST mean?

Check out BOTH of these links:
Sweet Spot Training
(http://www.fascatcoaching.com/sweetspot.html)Sweet Spot Part Deux: How to Sweet Spot (http://www.fascatcoaching.com/training_tips/SweetSpot_partdeux.html)

because the guys on the wattage board say to, and they know everything