Today, I ran a "Miracle Mile"workout in the Garmin Coach Jeff Galloway 5K plan. During this run, I accidentally hit the Lap button during the acceleration glider drill and my watch skipped past the run section to the cooldown section. I tried to undo this by immediately hitting the down button but the watch continued with the cooldown. I had to end this workout, discard it and start all over again. I saw some previous posts about the lap undo feature that indicate it doesn't work in structured workouts, which is probably why it didn't work in myGarmin Coach workout today.