questions on 2 x 20

portuguese mike

I've followed the the 2 x 20 thread with interest and i have a few questions:

What is threshold power - is it different to lactate threshold?

how often should you do a 2x20 session, is once a week adequate?

my main targets for the year are sportives, with the first being in May - is it too soon to include these sort of sessions into my training?

i was thinking of doing this sort of session on my commute home (i can easily alter the route to make it long enough) however the terrain is unavoidably rolling so there's no chance of a flattish 20min section - does this matter.

also it will be dark on my commute home until the clocks change therefore i won't be able to read my HRM or speed most of the time so will have to ride on PE - is this ok or should i get up earlier and do them on the way to work?

Sorry for starting a new thread but i thought it might get missed at the end of a long thread

thanks

bahzob

Heres my three hapence, others I am sure will also have views:

Threshold power/FTP: this is the average watts you can sustain over 60 minutes. Probably the best way to measure it is do a 25mile time trial but other means exist e.g. by doing a 20minute test and applying a frig factor. See here for more:
http://www.insidetri.com/portal/news/news.asp?item=101043

As the above link explains "functional threshold" is related to lactate threshold. I would not get too concerned about the differences. The main reasons for wanting to know functional threshold are that
- interval type training starts to be a appropriate at around threhold effort (go much below and its sufficient to measure overall ride time)
- its one measure of training progress, as you get better it should go up
- knowing where it is useful in pacing events. e.g. in sportives as a rule of thumb during long climbs I stay just under threshold, shorter happy to go over provided I know there's a recovery opportunity coming.

Rolling terrain: If it really is rolling then it should not matter, provided you feel you have a good independent measure of your effort that you can monitor. In fact it will be good training as one key skill is keeping pacing to keep effort steady during changing condtions. This will definitely help riding sportives. However if you have full on hills with descents that you cannot pedal at required effort then it will be difficult unless you can time the end of an interval to come at the top of a hill (if you can do this then it would be excellent drill, most of my "interval" training outdoors consists of riding up a succession of hills (we have lots))

Commute If you feel you can judge your PE on the rides home then it would be good to experiment using it as a measure, as again its a good skill to build up and will be useful during sportives in terms of pacing (as mentioned above). It will probably be interesting for you to look at actual HR when you get home, it may well differ from what you expect.