Different trainers would have different level of reaction time from the instance the interval power changes from say 100w to 120w. Some trainers take 2 seconds, some trainers up to 10seconds. All these reaction time is actually a good thing as, similar in real life, you don’t instantly go from 0% slope to 5% slope and then you basically grind to a halt.
However, it is also understandable that users may want to tweak the trainer lag so that the interval data (lap data) line up based on the intended timing. In this case, if you know the approximate reaction time of your trainer, you can utilise this feature to compensate (or anticipate early) and the app will send the command for the next interval just a few seconds earlier.
User defined Trainer Lag compensation. (Up to 10secs). Assuming that your trainer has a lag time of 4secs, putting it at 4secs, the app will send the Next Power Target (Slope% or Watt) per the structured workout to the smart trainer 4 seconds earlier so it will sync to the Next Lap Start.
BreakAway 