[Whilst watching Alan Stone's presentation about his 2012 trip kayaking down the Grand Canyon.]
Bashful +1 is 3 sets of 7x1-minute intervals at 125% FTP where recoveries between intervals are 30 seconds long and recoveries between sets of intervals are 6 minutes long.
Primarily, these efforts are about improving your maximum aerobic power or your ability to repeatedly operate at or near it.
Intervals like these can raise your aerobic ceiling and create room for later improvements in your VO2max, and in the process they'll bring about aerobic adaptations that benefit your performance across the board.
Strive for a cadence of 100rpm or even a bit higher during each interval. But if fatigue forces a lack of control at these higher cadences, shoot for something closer to 90rpm and ride smoothly.