NP and Training Response

i would venture to say that it depends. in senario 1, you are flooding your body with lactate, but not so much that you cant clear and buffer it as fast as you are producing it. also, your anaerobic system is "hot" but not in overdrive. in senario 2, your avg power is 225W, but like you said, there are many times you are over that. and when that occures, the anaerobic system goes from hot to overdrive. even though but senarios accumulate the same amount of training stress, the paths are different. like going from your home to the nearest Mal-Wart. there are plenty of ways to get to the same place. SO TO ANSWER YOUR QUESTION: it depends on your goals. if you are a crit rider, stick with senario 2. but if you want to do well in TT, senario 1.

I don't think they are the same. The NP from your group ride is similar to your power output during racing. You will spend a lot of time drafting. Is either you sit in or attack. I guess in the second case it can improve your 1 to 5 minutes power.

palewin said:

Is the training response the same or different for these two scenarios: (1) 2x20 at 225w (since effort is steady, NP will be same as AvP, 225w) (2) Group ride, with 40min NP = 225w. In the second case, the NP says that the effort is equivalent to 40 minutes at 225w, but the effort is made up of lots of short intervals above 225w and many below. So is the physiological adaptation the same? (The reason for the question is that I find the GR/NP case more enjoyable than going out solo for 2x20, etc., but I'm not sure whether the end benefit is the same.)

vio765 said:

i would venture to say that it depends. in senario 1, you are flooding your body with lactate, but not so much that you cant clear and buffer it as fast as you are producing it. also, your anaerobic system is "hot" but not in overdrive. in senario 2, your avg power is 225W, but like you said, there are many times you are over that. and when that occures, the anaerobic system goes from hot to overdrive. even though but senarios accumulate the same amount of training stress, the paths are different. like going from your home to the nearest Mal-Wart. there are plenty of ways to get to the same place. SO TO ANSWER YOUR QUESTION: it depends on your goals. if you are a crit rider, stick with senario 2. but if you want to do well in TT, senario 1.

ok, to really answer your question. i dont think the psysiological adaptation will be the same. in the TT effort, your adaptation will be clearing and buffering the lactic acid. and the more your body can clear, the more power you can produce. in the group ride effort, you will, on many occasions, go above LT and go into the anaerobic energy system. the adaptation there is that your body will be able to tolerate more acid, and therefor allow you to create more power (or the same power for longer). the end result is that senario 1 will more likely to help you in TT effort and senario 2 will help you in short bursts. personally, i would do both senarios becuase they accent each other somewhat.

I agree with vio and BJ that the two rides probably do not result in the same adaptations. I have a new program that buckets ride time by level based on both power and duration (it's a tricky problem). The group rides I have run this program against typically result in a bunch of time in L3 and L6, with a little L5 time and usually no L4 time. Basically, the durations >= the L4 floor aren't long enough to qualify as L4 efforts. It's for this reason that I consider group rides only so-so for training.

vio765 said:

...
in the TT effort, your adaptation will be clearing and buffering the lactic acid. and the more your body can clear, the more power you can produce. in the group ride effort, you will, on many occasions, go above LT and go into the anaerobic energy system. the adaptation there is that your body will be able to tolerate more acid, and therefor allow you to create more power (or the same power for longer). ...

vio765, I'd recommend you look at the following article:
http://wholeathlete.com/documents/Lactate_and_lactic_acid.pdf