"So, does the Pareto Principle have any relevance to run training, specifically to runs of three-to-four miles, runs of one hour, and runs of 1.5-to-2 hours?"
Leave it to my friend Carlos to drop a difficult question in my lap.
For those of you who have not dealt in matters economic or sociological, the Pareto Principle (not to be mistaken with the Peter Principle, where a person is always promoted one level beyond their competence), also known as the "80/20 principle," states that 80 percent of one measurable quality is produced by 20 percent of a population.
The first mention of the theory, attributed initially to an economist by the name of Vilfredo Pareto, had to do with crop yield; four-fifths of the harvest was produced by one-fifth of the farmland.
Management consultant Joseph Juran said that when it comes to gaining effectiveness in human endeavors, correcting 20 percent of the known weaknesses will, in theory, correct 80 percent of the problems. Once again, that's a theory.
When I began to think more closely about Pareto and the 80/20 ratio I found it aligned almost perfectly to several coaching observations:
"A person training for a marathon runs eighty percent of their training mileage at paces which are too fast, and twenty percent at a pace which is too slow." In a perfect world, the longest training run during the week would not exceed 25 percent of the training volume. Unfortunately, most of the packaged plans, regardless of the coach, are not prescriptive enough as to how intense the long run should be.
I guess its the Donald Rumsfeld theory of coaching; those knowable known, unknowable unknowns and perfectly good running socks which end up going missing in the dryer.
A marathoner who is capable of running continuously for two and a half hours at eight minutes per mile can reasonably consider twenty miles as their longest marathon training run. What drives me insane is to see a runner with a marathon goal performance of three hours, thirty minutes doing all of their long runs at nine minutes per mile for every mile of their long training runs. Oh, and the same pace goes for every mile of their "recovery" runs during the training week.
In order to race at a particular pace it's important to train at that particular pace. Long runs which start at 30 seconds per mile slower than the target pace and finish up at the target pace or a little faster, averaging out to the target pace, that's good.
"Eighty percent of a runner's mileage ideally are 'easy' runs, with the other twenty percent at lactate threshold or faster." Even the 5,000-meter race distance on the roads is an aerobic event, with more than nine-tenths of the race run using the aerobic energy system.
Dr. Jack Daniels recommends, in his "Running Formula," ten percent of the weekly training mileage to be run at the lactate (or aerobic) threshold, eight percent to be run near VO2max pace, and five percent at VO2max. The rest is to be run at intensities which are a minute slower than marathon goal pace...one where a runner could most likely engage in a discussion on the Pareto Principle.
A runner who takes the time to look at the biggest training bugaboos, having to do with training intensity and training mileage, are likely to take care of most all of the big problems which hold back their run performance.