Without consistency, there is no true peak in performance which can be achieved. The higher the goals, the more important consistency of training is, and there is no magical workout or training plan which can make up for a lack of consistent training.
Consistency may seem hard to do for many athletes, as it requires a HIGH level of commitment. There are plenty of times when training may need to take a back seat, but those with a commitment to consistent training find ways to get it done.
Consistency rewards those athletes who commit to it, because the performance levels reach new heights, many times beyond the athlete's highest expectations. Consistency of training for many months and years also provides an insurance policy to athletes who might have an injury develop, a sickness, or something else which takes them out of the routine for a week or so.
An athlete of mine has been incredibly consistent for the past 18 months, and has been showing abilities which put him in contention for a Kona slot at Ironman Texas. He had a foot injury of tendonitis that cut his running for a week, and his 3 year old daughter spent a week in the hospital with pneumonia, which you can imagine would make training difficult. He has been worried that everything he has worked for is slipping away, but in 2 week's time he is now amazed at how quickly his fitness rebounded, and how little he lost. I told him, "You cashed in the insurance policy your consistency for the past 18 months has provided."
He can't take many more weeks like those two he had, but his consistency helped cover the gap for him, much like an insurance policy.
Consistency rewards athletes who commit to it, in both performance, and in times of injury or other challenges. Commit to it, and get the rewards.