I think you have to be honest with yourself. If you’re pausing a workout mid interval to go get a drink or something to eat, then maybe you’re kidding yourself that you might have completed that interval in one go. If on the other hand you go grab a drink in between intervals then I don’t see that being as much an issue unless it takes you 2mins to get a drink when the recovery is actually only meant to be 30 seconds. Have you altered the physiological intent of the timings by getting off the bike midway?
TR usually asks you why you’ve struggled on a workout if you stop more than a few times or if you are always switching between erg and resistance mode. I’m guessing it will probably factor in a lower power average.
In the grand scheme of things, I doubt it will make much difference. But if you know it’s a thing, then prepare with snacks and drink to hand surely?
We all get the munchies, need a bottle refill, and I know I’ve sure dropped stuff when I’m on the trainer – I’ve even gotten a flat during an indoor workout!
As @mtbtomo and @AlphaDogCycling said, pausing your workout briefly during recovery blocks of your workout won’t impact your AI FTP Detections (or your Adaptive Training Progression Levels).
Pausing during an interval will trigger Adaptive Training to look into what’s going on.
Also keep in mind that should you experience interruptions for whatever reason wherever you are in your workout, it will be but a small point of data in a much larger set, so remember to consider the big picture of your overall training as well!
If I remember correctly, the cause was a worn-out rim strip. I had a wheel-on trainer, so I put the bike on, tightened the roller down onto the wheel, and within the first half of the ride, BOOM!
I was living at home at the time, so my dad heard the noise in the basement and came down to check it out. As a cyclist and former racer himself, he knew I didn’t like having my training sessions interrupted, so he helped me out by centering the rim strip as best as possible and fixing the flat in under 5 minutes – felt like having a personal mechanic!
This was before TR had come out with Adaptive Training and AI FTP Detection, so, of course, the kind of questions we see today regarding how these kinds of pauses affect our AT Progressions/AI FTP Detections didn’t come to mind on that day. This was back in the old “manual planning/testing” days when rim brakes were still alive and everyone still ran tubes!!
I had this happen too, only for me it was a little thorn or something embedded in the tire that finally found its way into the tube mid-workout. I was traveling and on a borrowed trainer, and the explosive sound coupled with a sudden complete loss of resistance (the flat tire was no longer contacting the wheel) had me momentarily thinking I owed my friend a new trainer (and everyone else in the house thinking something had detonated in the basement).