The more I hear about Boyle, the more I’m convinced he knows little about training speed. Perfect example of what I stated earlier. Do your research before claiming to be an authority or expert. Otherwise you are just misinforming people. Often these types of people will claim that “Team sports athletes should not train like track athletes.” Having trained athletes at elite levels in both track and teams sports, I know this is bullshit and a cover for “I don’t know how to train sprinters, so I’ll tell everyone that sprint training is useless for non-track athletes.”
Pioneer is much closer to the mark. Early in a speed development phase, you would be running sub-maximal sprints over short distances with shorter intervals (i.e. easy walk back). This allows you to get more reps in and work on postural issues during the start and initial acceleration. However, even for this type of work, 18 seconds would be ridiculous. As you approach maximum effort (90-95% of best time and above), you will use 1 minute per 10 meters of travel as an absolute minimum. If working with elite athletes (i.e. 100m sprinters running 10.5 or better), these recovery durations would be moved well beyond that duration. 30 meter sprints (standing, falling start) may require 4-5 minutes. Block starts even more. Other considerations may be temperature during the runs. If it’s really hot, you may take longer, as there is less concern of the athletes cooling down. In cooler environments, you may shorten recovery times (at the expense of lower intensities on the runs) to prevent the athlete from cooling down too much between reps.
Charlie was big on providing whatever recovery was necessary to keep the athletes running fast. 18 seconds will not do that - ever. If it takes 5 minutes between 30 meter runs, then you must take the full 5 minutes.