I’m on Week 3 of SSB1 and first time using AT. The week’s description says:
Once again, if you’d rather go easier but longer on Sunday, Boarstone is a good choice or take a look at Warren +1 if you’d like to include a trio of sprints early in your workout.
McGregror -3 (Achievable Sweet Spot) is currently scheduled for Sunday. If I delete this workout and insert Boarstone (Stretch Endurance) in its place will AT do the right thing?
what do you mean by ‘do the right thing’?
Firstly, if the plan isnt built with Plan Builde then AT wont give adaptions anyway.
AT wont replace future Sunday workouts with endurance if thats what you mean? AT will simply replace workouts of the same type with versions that are easier (lower PL) or harder (higher PL) based on your success rates and survey responses. It will never swap endurance for SST, or VO2 to endurance etc. It follows the plan as its originally created.
Then why are TR’s weekly notes telling me to replace the SS with endurance? 
I mean will AT recognize the substitution and give me credit for it?
…because the plan was written a long time before AT came along and used by many people with no AT access…
If you complete it, and its all set up via PB, then you will get credit for endurance, but it probably wont adapt any future SST sessions.
AT is pretty 1 dimensional really. It doesnt know how tired you are, if you prefer SST or endurance, how much time you may have or not etc. It simply knows if you completed a type workout and the difficulty rating its assigned, and then makes a call on whether future similar sessions (of the SAME type) will now be too easy or too hard. It then makes a suggested adaption, or not.
If you want to try a workout of a different type to the one on the plan you are supposed to use Train Now for a recommendation.
Yes, you will get credit for the ride (all caveats about recoding unit, etc.). But no, AT won’t adjust it based on your Endurance PL levels / any other criteria
I’ve been doing exactly this since June, replacing the Sunday Sweet Spot rides with a longer Endurance ride. Every week is the same result, once I skip or delete the SS ride, AT adapts all the following Sunday SS rides down. Not big deal honestly.
I suspect this might not happen if I was going through a plan with other SS rides throughout the week, so SSB1, I’m not familiar with any other plans that have SS sprinkled throughout.
I guess I have been assuming that SS is time-crunched Endurance. If you have time for Endurance then it is worth doing so that you will be all the more fresher for the Threshold and above workouts.
However either way, I guess at the moment there is no clear road to an alternate for when I have more time but I do not want to make the workout harder. The alternates for an SS workout are all harder if you increase the time.
@IvyAudrain Can we have Endurance workouts added to the list of alternates for SS workouts?
That would be interesting, but the endurance alternate would have to be longer.
I think it‘s physiologically more correct right now: If you want to do z2, choose the time you have available and your workout level for z2.
Of course any other capability goes up with more z2 as well. But the system now accepts only adaptions that are proven with workouts in this zone.
This is accurate. Alternates are primarily meant to train the same systems assigned in the original workout, so I think selecting an endurance workout via TrianNow instead will ultimately serve that purpose for you!