This post is an attempt to summarize my training philosophy toward middle distances.
I recently read an interview of Tirunesh Dibaba, three-time Olympic gold medalist (two in the 10,000 and one in the 5,000), in Running Times. The interviewer asked her how long her longest runs were.
Her answer? 90 minutes.
This is a woman who can run 14:11 in the 5,000 and sub-30 in the 10,000, and she never runs longer than an hour and a half. That's a profound thought for anyone who trains over 50 miles a week and can't break 19 in the 5K.
Of course, she has extreme talent, but the fact is, if you want to get fast, you have to run fast consistently. 7-9 hours a week is more than enough if you're looking to maximize your potential in sub-marathon distances, but you need specificity consistently over a long period of time if you want to get fast. Aerobic fitness is a critical and basic step to developing speed later, but there is a seriously decreasing marginal utility to that kind of training if you've been doing it for a long time.
Would a six-month Lydiard base period of 15-20 hour weeks help you realize your potential? Of course, but it's not going to make you all that fast unless you do something specific with it later. Period.
I've read lots about Lydiard, Canova, Maffetone and others. But, by far, the biggest influence on my training philosophy toward middle distance is my first running coach, Doug Bell -- badass masters runner and overall great guy.
Doug's philosophy is simple, but it's also profound, and I might say it's particularly meaningful the older you get. Doug does about 8-10 hard workouts a month, including races, and he makes sure to fully recover between those workouts. Once you have a base, the point of training is to maximize the effectiveness of your workouts. Any other stress is simply counterproductive, because it impedes the supercompensation cycle. Even when he was a 14:30 masters 5K guy, you'd rarely see him running much faster than 8-minute pace on his easy days. He does intense workouts consistently, probably 11 months a year, and over the course of many years that has enabled him to become one of the best age group competitors in the world.
That's it. So, if you're currently an 18:30 5K runner (that's probably where I am right now, if I'm lucky), and you want to get faster, your easy days should be closer to 9-minute miles than 8-minute miles, and they certainly shouldn't be in the 7s. But, that said, you gotta bring it to your workouts.
In conclusion, if you want to get fast, your long runs don't need to be that long. If 80-90 minutes is long enough for a three-time Olympic gold medalist, and 50 miles a week is good enough for one of the world's best age-group competitors, I'm going to go out on a limb and say it's long enough for the rest of us, too.