I know that power-based training is all the rage for road training regimens (5x5, 2x20 intervals, etc), but is there any data on the usefulness of power-based interval training for track purposes? I would imagine there would be some usefulness, but from the little I have learned about track so far, all training is all-out efforts, then rest, as opposes to %'s of FTP. Any thoughts on this?

track racing isn't all about all out efforts. you have a lot of enduro type races like the scratch, miss n out, win n out etc... A lot of top sprinters have powermeters on their bikes. Having a powermeter is just another tool for training (don't want to get into that whole debate)

As Impreza_aL has already said there is benefits.

Including as mentioned specific efforts for enduro efforts, training for pursuits / pacing and aero testing...

https://www.trainingandracingwithapow...it-part-1.html
https://www.trainingandracingwithapow...it-part-2.html
https://www.trainingandracingwithapow...it-part-3.html
https://alex-cycle.blogspot.com/2011/...us-faster.html

I have a power tap wheel for track. I use it for aero testing and measuring efforts. For example, I can do flying kilos at the track at a certain power level depending on the training goals.

I can also do a flying kilo and have a timer calling out lap times. I may want 18 second lap, 250 track, which would yield a 1:12 kilo. However, I can set the target lap time to whatever I want.

So a stopwatch and another person to time efforts is very helpful on the track and may be more significant than power measurement. For example, a 1/2 lap time after a full power standing start is a good measure of a sprinters start and acceleration. One can choose different gears and optimize the 1/2 lap starting time. However, a power profile can also be useful in showing weakness off the line or during initial acceleration.

One thing I have found is that the TSS generated from the Training Peaks and other software is bogus for the track. IMO, the efforts, especially full power sprints, are very fatiguing but do not score a high TSS.

On the whole, IMO, power measurement is an excellent tool at the track.